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Development of Vehicular and Personal Universal

1. 10 00 14 99 Other Yes 15 00 19 99 Ga know refuse d Yes 20 00 24 99 Yes 25 00 29 99 If final destination answer is no Yes more than 30 00 4 If answer is No and previous mode is not Auto truck van If final destination answer is yes 26 Copyright 2011 AHMCT Research Center UC Davis GPS Automated Travel Diary User Guide GPS ATD Passive Mode Menu Flowchart n N Thank you Have a safe trip Continue traveling Stop traveling M 4 17 a 21 Welcome to the dr 1 ave you stopped Begin a new trip No Yes l m making a stop 4 Yes This is my final destination u 4 27 gt Your trip is finished Thank you for your cooperation ok u 4 21 Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology APPENDIX D DETAILED DELIVERABLES PROVIDED BY CALTRANS TSI 97 Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology 98 Copyright 2011 AHMCT Research Center UC Davis DELIVERABLES The contractor shall at a minimum accomplish the following deliverables to meet the objectives of this contract 1 Review literature and products on a Human Computer intera
2. This manual contains safety instructions that must be observed in order to avoid potential hazards that could result in personal injuries damage to the GPS ATD or loss of data Warning e f you notice any abnormal conditions such as odor smoke or overheating disconnect the AC or Auto charger adapter Continued use of the GPS ATD may result in fire electronic shock or burn and serious injury e If water or other liquid gets inside the GPS ATD immediately disconnect the AC or Auto charger adapter Please return the GPS ATD for service as soon as possible Continued use of the GPS ATD may result in fire electronic shock or burn and serious injury e If you drop or damage the GPS ATD please return the GPS ATD for service as soon as possible Continued use of the GPS ATD may result in fire electronic shock or burn and serious injury e Do not disassemble modify or repair the GPS ATD unit Any modification may result in fire electronic shock or burn and serious injury e Do not allow any foreign objects such as water metal or liquids to enter or drop into the GPS ATD connector ports or other openings or gaps Such objects may result in fire electronic shock or burn possibly in serious injury e Do not use the GPS ATD on an airplane or near medical equipment or in any other location where use of personal electronics is expressly limited e Do not use the GPS ATD in a place that is exposed to water e Do not use the GP
3. o Bending with force twisting or bundling Copyright 2011 AHMCT Research Center UC Davis Copyright 2011 AHMCT Research Center UC Davis GPS Automated Travel Diary User Guide TABLE OF CONTENTS USAGE 1 71 2011 Ton M iii Safety DFeCOUllOHs s fO ONERE RI lii Warn NU UE AEG iii FA TITO RETO cA vii TEASE OF FIi ures ne zzz o aaa ia E A EAO OO ix BASE OF Tables seo ROAR E UI xi DisclamnercDISClOSUFO s neh eis xiii List of Acronyms and Abbreviations ecce ecce eee eee eene eee e eene co 00000000000000000000000000 xv Section I Welcome amp INITOAUCHON eio R OO 1 About tbe GPS A DD 52i ero oes 22a BR RE RE Ri 2 Sechon 2 P rt ATAM eet 3 SECHNON I DELED esse sine 7 Section 4 Basic operation for USETS ccccccrssssscccccccccsssssssscccccccccccccsssscsscccccsccsssscsccccsees 11 Section 5 Downloading Df u a lau 17 Travel Survey Respondents 222 OE OOO 17 Authorize GPS ATD Administrator ssssssssssssssssssnnnnnnnsnsssnnnnnnnnssssssssssnnnnnnsssssssssssnnee 17 Section 6 Frequently Asked questions scccccccssssssssssscccccccsssssssscscccccssscsssssssssccooees 19 SOCIO 72 SPECILCAHONS ausruhen 21 APPENDIX A ATD MENUS Flowchatrt sssssssssssssseccccosssssseeeccocsssesceccccocosssssseeesoso 23 vu Copyright 2011 AHMCT Research Center UC Davis Copyright 2011 AHMCT Research Center UC Davis GPS Automated Travel Diary User Guide LIST OF FIGURES Figure L GPS ATD Usage Diagram sca
4. GPS ATD USER GUIDE 95 Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology 96 Copyright 2011 AHMCT Research Center UC Davis California AHMCT Program University of California at Davis California Department of Transportation GPS Automated Travel Diary User Guide for Caltrans Firmware Version 0 1 0 Kin S Yen Stephen M Donecker Kimball Yan Travis Swanston Bahram Ravan amp Ty A Lasky Principal Investigator AHMCT Research Report UCD ARR 06 12 31 01 Appendix C o oc December 29 2006 Affiliations The authors are with the AHMCT Research Center Department of Mechanical amp Aeronautical Engineering University of California Davis CA 95616 5294 This report has been prepared in cooperation with the State of California Business and Transportation Agency Department of Transportation and is based on work supported by Contract Number RTA 65A0189 through the Advanced Highway Maintenance and Construction Technology Research Center at the University of California at Davis Copyright 2011 AHMCT Research Center UC Davis Copyright 2011 AHMCT Research Center UC Davis GPS Automated Travel Diary User Guide USAGE WARNING Do not interact with the GPS ATD while driving a vehicle Please enter the answer the survey before driving or after you have stopped your vehicle SAFETY PRECAUTIONS
5. Medical 16 Medical appointment surgery treatment pick up prescription EA Recreation Entertainment _ _ o 17 Fitness activities gym health club playing sports ummmsnsnssssssssunsnssnunnusunununnne Loococ000000000000000000000000000000000000000000000000000000000000000000000000000000000000 000 00 000000000000000000 0 o 222020000006000060600006060060606000060600606060060606606060660606066060600006060000600000000000000000000000000000 20 jVisitfuends relatves 21 _ Community meetings political civic event public hearing voting etc 22 Occasional volunteer work 235 Church temple religious meeting 0 NENNEN Personal 1 24 Buy fuel for vehicle gasoline diesel station _ 25 Incidental shopping groceries house wares over counter drugs etc 26 Incidentaleating drinking ie coffee 27 Major shopping house furniture clothes purchase a vehicle etc 28 ATM banking post office utilities 0 0 gt Other o LLL EE Ground Access to Airport 0 0 30 _Home Airport Airport Home eee 31 Hotel Airport Airport Hotel 321 Business Airport Airport Business 0 Other Out of Home 33 With another person at their activity 89 Strikethrough are confidential fields Copyright 2011 AHMCT Research Center
6. 0 55 mm anti pads based on manufacturing tolerances However this setup did not allow avoidance of all necessary pins using standard via locations hence we used via in pad for the CPU This presented some manufacturing challenges for the PCB fabricator both in cost and time It turns out that caps on the in pad vias used so that the BGA sees a flat circular pad can pop up during reflow process if any gases are trapped during the via fill and cap process This choice allowed us to continue with the 6 layer design and escape the majority of pins in the two signal layers with some less critical pins escaped on the top and bottom layers since the Flash level transceiver was an 0 65 mm pitch BGA via in pad was again required for pin escape Since the via process worked well it was also used for the larger 0 80 mm pitch SDRAM BGA which allowed for much easier pin escape All routing between the CPU and memory devices was constrained routed simulated and met timing and noise requirements The SDRAM was designed to operate at 133 MHz and the NAND Flash at 66 MHz The design was simulated on Agilent ADS software and laid out accordingly on the PCB The two stage LNA Low Noise Amplifier was placed as close as possible to the PCB mount antenna and the LNA output was as close as possible to the GPS module input The ZigBee CPU was placed 57 Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudi
7. 7 Pick up Drop off Are you the driver or a Welcome to the passenger Automated Travel Diary Thank you Have a safe trip Pick up someone Drop off someone 1 2 3 4 5 6 T 8 Get picked u 9 Passenger What is your trip Get eae a d ww or more d Continue traveling Driver Begin a new trip activity Stop traveling u d Home 1 IT Please select a trip u 4 Travel SA ce 4 4 Pick up Drop off activity en Work l selget transit type m Education childcare Work include scheduled and Were there any parking Dining volunteer work cost on your trip Local bus Recreation entertainment Work related meeting errand Please select a trip Express commuter bus Social civic religious ete 4 activity sub category No Select mode of travel Light rail street car Personal Education childcare Yes prepaid trolley School preschool K 12 grade Yes less than 1 00 Cable car Medical E School college or vocational p gt Yes 1 00 1 99 Auto truck van Coaster Other out of home ac ivity lease select a trip 3 Childcare day care befor
8. Entered Data Specific Information Household Region TBD TBD Etc Household Address i Varah a a I D LU ud gt U City County Pre entered menu option i e 1 Alameda 2 Alpine etc State Zip code Type of Dwelling Unit Unattached single family home Duplex Apartment Condominium or townhouse Mobile home or trailer Group quarters dorms barracks etc Other Don t Know Refused Owner Renter Status Own Rent Other Don t Know Refused Number of Persons in Household Ordinal Variable Don t Know Refused Number of Vehicles in Household Ordinal Variable Don t Know Refused OIA Nin BR WN m 79 Strikethrough are confidential fields Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology HOUSEHOLD INFORMATION Table 1 continued Pre Entered Data Code Vehicle ID Number Veh 1 Vehicle ID Number m M N M n Code Vehicle Model Year Text Vehicle Make and Model Honda Accord etc 4 Digit Model Year Don t Know Vehicle X Body Type Automobile Van RV Sport utility vehicle SUV Pick up truck Other truck Motorcycle Moped Other specify Don t Know Vehicle X Fuel type Gasoline Diesel Electric
9. GPS signal amplification sub sections primarily the LNA are subject to interference from other on board components Future revisions must provide better 1solation from noise radiated by other on board circuitry through proper physical shielding of both the GPS signal LNA and the GPS module Furthermore future revision must better mitigate any conducted power noise to both the GPS signal LNA and the GPS receiver module through better power filtering and ground plane isolation this can be achieved by connecting the RF ground plane to the digital ground plane through narrow traces that act inductively In addition any new design should employ newly available lower power GPS receiver modules using SIRF III LP or MTK chipsets Due to time limitations some software and hardware features such as ZigBee OBD II reader a more efficient data storage format ZigBee communication software audio prompting software and power management software were not implemented These features would enhance the GPS ATD capability considerably Of most importance for the full scale use of the GPS ATD n a real world travel behavior survey such as the pending 2010 California Statewide Household Travel survey the Phase II post processing and automation will be essential A Stage II research effort would develop data analysis automation tools suited for a longitudinal travel behavior survey that uses the GPS ATD units While it 1s clear that the GPS ATD prototypes ha
10. Nevertheless these large positional errors can be eliminated by map matching and or use of inertial sensors such as a rate gyro 4 15 24 GPS receiver performance varies for different models and manufacturers They all have different internal proprietary positional solution routines and Kalman filtering for invalid GPS positional solutions 18 Therefore intensive testing on different GPS receivers must be performed to determine the model best suited for the traveler behavior survey data collection application Commercially available GPS receivers and components were evaluated on their e size power consumption and weight e cold start acquisition and re acquisition time in open sky as well as in harsh GPS signal environments 31 Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology e and availability and accuracy in various indoor situations such as metal and concrete buildings concrete parking structures household garages as well as outdoors in urban canyons heavy tree cover and open sky In addition various GPS antennas were tested for performance in different conditions particularly for signal loss at varlous orientations and the effects of human tissue in changing the antenna signal gain pattern 16 Size and weight were also compared Low Cost Inertial Sensors for Dead Reckoning Dead reckoning DR is a n
11. S Yen Stephen M Donecker Kimball Yan Travis Swanston Ayalew Adamu 8 Performing Organization Report No Leo Gallagher Mohammad Assadi Bahram Ravani amp Ty A Lasky UCD ARR 06 12 31 01 9 Performing Organization Name and Address 10 Work Unit No TRAIS AHMCT Research Center UCD Dept of Mechanical amp Aeronautical Engineering 11 Contract or Grant Davis California 95616 5294 RTA 65A0189 12 Sponsoring Agency Name and Address 13 Type of Report and Period Covered California Department of Transportation Final Report Division of Research and Innovation January 2005 December 2006 P O Box 942873 MS 83 Sacramento CA 94273 0001 14 Sponsoring Agency Code Caltrans 15 Supplementary Notes 16 Abstract This report provides an overview of travel surveys including literature review and background as well as the motivation for the research and development of the Global Positioning System Automated Travel Diary GPS ATD The system requirements and specifications for the device development are presented and discussed In addition the detailed architecture hardware software and user interface design are included Vehicular and personal GPS ATD systems were developed to support comprehensive traveler behavior studies The GPS ATD provides an intuitive user interface to capture trip activity information trip purpose travel mode etc with minimal user input and burden during travel surveys Each survey participant interac
12. SECTION 2 PART DIAGRAM Battery Status Menu Selection Area Selection s highlighted GPS Antenna OK Select Key GPS ATD Status Area Question Area Back Cancel LCD Display Key Figure 1 GPS ATD Usage Diagram Copyright 2011 AHMCT Research Center UC Davis GPS Automated Travel Diary User Guide Power Charging USB Data Port Figure 2 GPS ATD Side View The GPS ATD has an LCD display which is divided into three areas e GPS ATD status area located at the very top e Question area located in the middle within a rectangle and e Menu Selection area located on the bottom of the display Please note that the selected item 1s highlighted The GPS ATD has four keys located next to the LCD display e The user moves the desired selection item by pressing the Up or Down key e the User may cancel the selection and go back to the previous menu by pressing the Back Cancel key and e the user picks the selected menu item by pressing the OK Select key Do not forcibly press in the buttons on the front surface The user should hear and feel a click when the button is activated Do not place the GPS ATD in a trouser pocket When you sit down the GPS ATD could receive a strong impact and be damaged A typical fully charged battery will allow for eight hours of continuous GPS ATD operation The user can recharge the battery at an
13. TOS EET TT TTD TQ TR 73 APPENDIX A GPS ATD MENU TODOS Aiii tete en anal 77 VEHICLE RR RE ers 86 IRIPACTIVIIY z WE O R IO HII UE NI Eu 88 TRIP PURPOSE 82823 885288 90 APPENDIX B GPS ATD Menu Flowchart eee ee eese eee eee eene eerte 93 APPENDIX C GPS ATD User Gilde aussen 95 APPENDIX D Detailed Deliverables Provided by Caltrans TSI 97 vili Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology LIST OF FIGURES Figure 1 WAAS geostationary satellites coverage map http gps faa gov CapHill geosat htm 29 Figure 2 WAAS GPS vertical accuracy map http www nstb tc faa gov vpl html 29 Figure 3 Example commercial GPS receivers 0 00020000000000000000 00000 nn anao nn nn nn nn WO Ek EG nun nn nenne 31 Figure 4 Analog Devices MEMS gyro and accelerometer chipS 00000000oooo0oo000000000000000000000000000000 32 Figure 5 System architecture including data collection and post processing phases 35 OPI elut iN vli er 44 Figure 7 Residential streets with tree blockage eooooooooooooooooooooo000000000000000000000000000000000000000000000000000000 45 Figure 8 Bridge test results for SiRF II SiRF III and Sony GPS receivers number on symbol indicates number of satellites us
14. UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology TRIP PURPOSE Table 5B Hybrid Mode User Input Drop off someone or get dropped off of person TRIP PURPOSE What is the purpose of this Trip From OOOO To Home 2 Workplace 2 3 Work related OoOO 3 4 Social or entertainment EEE 5 Recreation national parks theme park etc 5 6 Shop ee 7 School eee 7 8 Other use other for anything not shown above 8 90 Strikethrough are confidential fields Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology TRIP Table 6 User Input 91 Strikethrough are confidential fields Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology NE VehideOccupancy Number How many total people were in the vehicle at the start of your trip including NE oO Don t Know Refused Personal Vehicle Parking Cost 0 00 Parking Cost Unit in dollar amount _How Do You Pay for Parking Hourly Daily Weekly Monthly Quarterly Annually None Subsidized Other l 2 3 4 5 6 7 8 9 Toll Co
15. Universal Longitudinal Travel Diary Systems using GPS amp New Technology 8 layer board 130 components 470 parts ZEE rec un GPS RF GPS Gyro and ZigBee Amplifier Module Accelerometers Wireless WAFYRE ZET f NL fe sus u Rad F ex m Ta z RAB FL Ties uf CB i th E e ei rege E ot i AL rez 2 8 z i Mi m LE E ul Cal gaa gt wi ara at aj je LE TE P E B LEES i px ATH e WWAN cu a Lrrmm J kal bu u mn USB SDRAM CPU 256MB NAND Flash zw M C189 cor cry Se aT LLL ME inir C125 Cle f cin T BI Kur II ee LUE pa USC ell j gi T gt ont t LE LI LIE UE TR ciTe 114 i ise a w m 1B di REA Os Ed AE LS CET A PIS cose Four DC DC Switching Power Supplies AHMCT UC Davis Alhama Figure 21 Assembled GPS ATD circuit board bottom side 59 Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology GPS ATD Manufacturing Due to the small volume of GPS ATD fabrication the ma n GPS ATD boards were assembled in AHMCT s Sensing and Communications Lab This was a significant manufacturing challenge due to small component package size system complexity high number of parts and mainly the new Restriction of Hazardous Substances RoHS soldering process required by the new semico
16. a day 7 days a week from the Coast Guard s Navigation Center in Alexandria Virginia NDGPS also provides GPS integrity monitoring capability it gives an alarm to users within 6 seconds of detecting a fault with the signal from any GPS satellite in view NDGPS receivers are generally much bigger and consume more power because of the extra MF 150 175 kHz radio modem The Federal Aviation Administration FAA Wide Area Augmentation Service WAAS GPS differential correction signals enable even higher positional accuracy 1 3 m without the need for an additional FM radio WAAS broadcasts correction signals by geostationary satellites and uses a system of ground stations to provide necessary augmentations to the GPS navigation signal A network of approximately 25 precisely surveyed ground reference stations are strategically positioned across the country including Alaska Hawaii and Puerto Rico to collect GPS satellite data The system is then able to estimate the amount of signal delay and error that is the result of the ionospheric and or solar activity This information is then passed on to the user as a part of the WAAS navigation message to correct GPS signal errors These correction messages are then broadcast through communication satellites to GPS receivers using the same frequency L1 1575 42 MHz as GPS WAAS is designed to provide the additional accuracy availability and integrity necessary to enable users to rely on GPS within the te
17. an identical SiRF III module to compare their performance on the open highway and in a parking structure The performance of the SiRF III GPS with Sarantel GeoHelix antenna is slightly less than with a patch antenna The GPS signal received is about 3 db less with the GeoHelix antenna However the GeoHelix antenna should out perform the patch antenna if the patch antenna is oriented sideways or upside down according to manufacturer s literature Thus the Sarantel GeoHelix is better suited for handheld applications where orientation varies Therefore it was selected for the personal GPS ATD Based on the same tests a patch antenna was selected for the vehicular GPS ATD Figure 13 Sarantel GeoHelix GPS antenna GPS Antenna Placement Simulations simulations were run to determine the performance degradation of placing the GPS patch antenna on the dashboard instead of the roof The vehicle metallic roof was simulated as a perfect GPS signal block The effect of the metallic roof blockage depends on the vehicle travel direction The effect 1s less when the vehicle is traveling south as shown in Table 10 and Figure 14 Generally the vehicle metallic roof will block one to two satellites However the GPS antenna still receives more than four satellites to give a positional solution Based on the simulation results we concluded that the ease and convenience of GPS antenna installation on the dashboard outweighs the performance gained by placing t
18. and low cost GPS receivers 21 Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology GPS is continuously being modernized with additional radio frequency and transmission power resulting In more reliable and accurate positional and time solution However civilian users will not benefit from the effects of in progress and planned GPS modernization until 2008 Free Nationwide Differential GPS DGPS Services GPS accuracy can be improved by additional information provided by fixed ground GPS monitoring stations The Wide Area Augmentation System WAAS and the Nationwide Differential GPS NDGPS are two free differential GPS services available in the United States Both systems provide improved GPS accuracy and integrity monitoring services NDGPS is a land based GPS augmentation that typically provides l to 3 meter positioning accuracy to receivers capable of receiving the differential correction via a Medium Frequency MF signal transmitted by a ground station It s an expansion of the U S Coast Guard s Maritime DGPS network NDGPS is now providing single station coverage over about 80 of the landmass of the continental U S and is expected to be fully operational with dual station coverage throughout the continental U S in the near future To ensure accuracy integrity and continuity NDGPS is managed and monitored 24 hours
19. based or activity based survey 31 Place based surveys focus on respondent movements from one place to another during the survey period 31 Survey methods evolved from the mail out mail back Paper and Pencil Interview PAPI m the 1960 s through the Computer Assisted Telephone Interview CATI in 1980 s to the Electronic Travel Diary with or without GPS of today 31 Computer Assisted Self Interview CASI methods in which respondents input their travel information directly into a computer have become widely used 17 However respondents are required to have access to a computer and the Internet Each method improved upon the previous approaches by better capturing incidental trips reducing underreporting improving data accuracy and minimizing respondent burden and fatigue Nevertheless gathering complete information from travelers has been problematic Drawbacks of self administered paper based survey designs are well known and this approach is not suited for long term mobility pattern observations Moreover multi day personal surveys often suffer the ll effects of survey fatigue and low response rates typical 1n longer survey durations 23 It is common for respondents to underreport or to provide incorrect data due to poor memory misunderstanding instructions or carelessness Short or infrequent trips that occur during the day are the most often not reported 23 20 Copyright 2011 AHMCT Research Center UC Davis
20. eee e ette eee eese ee eeu 42 Table 10 Number of available satellite summary statistics 000000000000000000000000000000000000000snnnnnnnnnnnnnne 49 Table IT GPS ATD Systeni hardwarca ecco ENSE LECHE NR e stends Nessie 54 XI Copyright 2011 AHMCT Research Center UC Davis Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology DISCLAIMER DISCLOSURE The research reported herein was performed as part of the Advanced H ghway Maintenance and Construction Technology AHMCT Research Center within the Department of Mechanical and Aeronautical Engineering at the University of California Davis and the Division of Research and Innovation at the California Department of Transportation It is evolutionary and voluntary It is a cooperative venture of local State and Federal governments and universities The contents of this report reflect the views of the authors who are responsible for the facts and the accuracy of the data presented herein The contents do not necessarily reflect the official views or policies of the State of California the Federal Highway Administration or the University of California This report does not constitute a standard specification or regulation xili Copyright 2011 AHMCT Research Center UC Davis Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Uni
21. shows a typical battery voltage discharging curve The 67 Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology battery discharges from a fully charged state of 4 15 V to a fully discharged state of 3 5 V At 3 5 V the battery protection circuit automatically disconnects the battery from the load and hence prevents any over discharging of the Li ion battery GPS ATD Battery Charging Voltage Profle Battery Voltage Volt 120 140 Time min Figure 30 GPS ATD battery charging curve Operational GPS ATD Battery Discharge Profile o o o UG o gt gt 2 U a 0 40 80 120 160 200 240 280 320 360 400 440 480 520 560 600 640 680 Time min Figure 31 GPS ATD battery discharging curve 68 Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology Initial pilot testing by the Caltrans TSI team found that the units are very portable and easy to use It generally takes the user one to two minutes to answer all trip related questions AHMCT is now conducting on going prototype field testing with Caltrans and early field testing feedback is positive A COTS PDA holder may be used hold and mount the personal GPS ATD in a vehicle or on a bicycle shown in Figure 32 or motorcycle The personal GPS
22. when the user s traveling When the user finishes the current leg of the trip they should press the down button and then the OK Select button to select the Stop traveling menu 13 Copyright 2011 AHMCT Research Center UC Davis GPS Automated Travel Diary User Guide After that the user has to confirm whether they have arr ved at the end of th s leg of the trip by selecting either Yes I am making a stop or Yes This s my final destination If the user selects Yes I am mak ng a stop the menu loops back and asks the user information about the next leg of the trip If the user selects No the menu will loop back to the previous menu This is designed to trap accidental key presses If the user selects Yes This is my final destination then the user is asked the post trip questions as discussed below Next the user will be asked to answer a set of post trip questions related to cost of travel such as fare cost parking cost or toll cost 14 Copyright 2011 AHMCT Research Center UC Davis GPS Automated Travel Diary User Guide If the user has selected Yes This is my final destination in previous menu the following question figure will be shown to the user Once the user selects OK by pressing the OK Select button the user has completed the travel survey for this trip The complete menu flowcharts of all three modes ar
23. with available manufacturing technologies Small package components usually have finer pitch and smaller electrical contacts for soldering onto the main printed circuit board PCB The finer the component s pitch the more costly it will be to place onto a PCB by pick and place machines Even though new low power components may cost less because of smaller die and package resulting increased manufacturing difficulty may negate any cost savings 51 Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology Thus component selection is an iterative process whereby the designer must balance power cost size manufacturability and availability GPS Satellite AX bu AU Wireless communication with Embedded 240x160 other GPS ATD GPS LCD Display HMI Digital Input Module i i AA Wireless Ireless Communication SOC Embedded On Board Arm SDRAM Processor On Board Flash ZigBee Clock ODB II Interface Audio Output Temperature Sensor To Car MEMS Gyro 8 Computer Four Switching Accelerometer Power supplies 5 VDC Power input Figure 15 GPS ATD system block diagram Once major components are selected schematic design may start However the detail design is carried out simultaneously with the c
24. 1 4 1 mumbersatelies 4 1 4 1 velocity HDOP OBD II oxygen sensor 1 Oxygen sensor 2 Temp ADEL ACER Gyro Accel Identity olo 8 01 8 0 002 0 002 0 002 0 002 Trip 0 002 Linktrp dropoff 2 0 001 0 002 1 0 002 total bytes sec 164 01 duty cycle storage size MB 128 maximum days 31 57 NO 40 Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology Design Tradeoffs Table 9 represents the relationships between the system features and their influence on weight s ze cost user burden data quality battery duration and survey duration The system features are the row headings and the major constraints are the column headings The colors and numbers represent the effects of including or increasing one of the features with red or 3 representing a very negative bad effect and blue or 3 representing a very positive good effect As an example by increasing the display size feature we see that the weight would be slightly increased negative the size would be more increased more negatively impacted and the cost would be greatly increased very negatively impacted We see that by increasing the display size the user burden is somewhat reduced positively effected The battery duration 1s negatively effected as larger screens use more pow
25. 1 99 Is there a change of 5 Recreational parks etc Yes 2 00 2 99 drivers 6 Shop d Yes 3 00 3 99 7 School Yes 4 00 4 99 No 8 Other Yes more than 5 00 Yes 9 S Select transit type 10 or more u 4 Were there any parking cost on your trip 24 Local bus 4 Express commuter bus Light rail street car trolley Are you picking up or Cable car Dropping off person s No Welcome to the Coaster What is the purpose of Yes prepaid Automated Travel Diary SAB use o GU red Ferry your trip From No Yes less than 1 00 Metro Blue Line Pick up someone Yes 1 00 1 99 Auto truck van diete Gus Line P Home Drop off someone Have you stopped Yes 2 00 2 99 Public transit Metro Red Line Work place Get picked up Yes 3 00 3 99 Other BART Work related Get dropped off Begin a new trip i Yes 4 00 4 99 u d s Metro Link Social or entertainment s d Ho SR pee Yes 5 00 9 99 Heavy Rail Caltrain Recreational parks etc Ms g MR s E Yes 10 00 14 99 Yes This is my final destination Amtrak Shop Yes 15 00 24 99 n an transit UN 1 87 h u Yes 25 00 29 99 If answer is No and Chool related Dus er Yes more than 30 00 previous mode is por u Sup ce u Auto truck van eer u d ick up Drop o 1 5 2 4 3 21
26. 26 4 a gt p gt Select type 5 T Your trip is finished Thank Are you changing your 6 Mie ae Did you pay fare on this you for your cooperation model of travel On foot 7 mos A m trip Bicycle 8 imo or Intercity bus ok Motorcycle moped 9 No Taxi shuttle bus limo 10 or more Yes prepaid Yes Intercity bus Greyhound etc u 4 a R than 5 00 u 4 d Airplane commerical ye 5 00 9 99 Airplane private Yes 10 00 14 99 Other Yes 15 00 19 99 Ga know refuse d Yes 20 00 24 99 Yes 25 00 29 99 If final destination answer is no Yes more than 30 00 4 If answer is No and previous mode is not Auto truck van If final destination answer is yes 26 Copyright 2011 AHMCT Research Center UC Davis GPS Automated Travel Diary User Guide GPS ATD Passive Mode Menu Flowchart n N Thank you Have a safe trip Continue traveling Stop traveling M 4 17 a 21 Welcome to the dr 1 ave you stopped Begin a new trip No Yes l m making a stop 4 Yes This is my final destination u 4 27 gt Your trip is finished Thank you for your cooperation ok u 4 21 Copyright 2011 AHMCT Research Center UC Davis Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology APPENDIX C
27. 5 was driven by the design requirements Hardware design focused on portability light weight small size and low power consumption Once the actual system architecture was developed appropriate components to implement the system functions could be selected The GPS ATD is composed of following major components ABS plastic case LCD display panel with built in backlight custom membrane switch user interface 1800 mAh Lithium ion battery and the main circuit board with all the electronics The LCD panel and battery are assembled into the GPS ATD unit with little modification The battery capacity was limited by the size of the GPS ATD case Other components are custom design or COTS with major modifications Component selection principles were based on availability package size power consumption technical specification and cost No single criterion 1s necessarily more important than any other In order to extend the battery run time as long as possible each component s power usage must be scrutinized carefully The GPS receiver module SDRAM synchronous dynamic RAM and CPU were the major power consuming devices on board In addition to selecting inherently low power components one must also select components that allow lower voltage supply levels Components that quickly change binary states such as the CPU use power based upon the voltage supply and the digital communication data bus voltage to other components Therefore SDRAM and 32 bit AR
28. 6 27 28 29 30 31 32 33 Cost Rate Gyro n Institute of Navigation GPS Conference Portland OR September 24 27 2002 E I Pas Multiday Samples Parameter Estimation Precision and Data Collection Costs for Least Squares Regression Trip Generation Models Environment and Planning A18 pp 73 87 1986 E I Pas Intra Personal Variability and Model Goodness of Fit Transportation Research 21A pp 431 438 1987 E I Pas Weekly Travel Activity Behavior Transportation 15 pp 89 109 1988 E I Pas and F S Koppelman An Examination of the Determinants of Day to Day Variability n Individuals Urban Travel Behavior Transportation 14 pp 3 20 1987 R M Pendyala Measuring Day to Day Variability in Travel Using GPS Based Data Set Federal Highway Administration Rept DTFH61 99 P 00266 Tampa FL 1999 M Petovello O Mezentsev G Lachapelle and M E Cannon High Sensitivity GPS Velocity Updates for Personal Indoor Navigation Using Inertial Navigation Systems in Institute of Navigation GPS Conference Portland OR September 9 12 2003 A J Richardson R K Seethaler and P L Harbutt Design Issues for before and after Surveys of Travel Behaviour Change in 26th Australasian Transport Research Forum Wellington New Zealand October 1 3 2003 2003 J L Shewfelt R Nishikawa C Norman and G F Cox Enhanced Sensitivity for Acquisition in Weak Signal Enviro
29. 8 Canada March In vehicle GPS only 1999 Georgia Institute 2000 ETD and comprehensive in vehicle data collection of Technology system with both GPS technology and an engine monitoring device gt 100 Ibs 34 Diary Stopher s pilot 1999 Vehicle passive logging with Garmin GPS III max experiment 1900 point 29 GeoStats Logger Passive logger using Garmin 35 GPS sensor with 4 MB max storage 1 0 or 0 2 Hz logging rate 1 lbs McNally UC 2002 X86 133 MHz CPU running embedded Linux with Irvine CA 16 MB for 28 hours data logging GPS amp CDPD modem Estimated cost size amp power 1 200 1 400 7 x9 x4 4 watt Limited to Vehicular use Georgia Institute 1999 Psion WORKABOUT handheld 16 MB storage of Technology 240x100 pixel display with key input 11 46 ounces Handheld Travel 2 AA batteries 8 only Used in a survey of 25 Orange County households in which all homes are newly built n a new residential development 17 23 Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology Previous longitudinal surveys utilizing GPS refer to Table 4 have shown great potential 1 3 7 23 33 GPS based surveys are more accurate and minimize the respondent burden In addition GPS digital data can be readily imported into computer analysis programs This approach captures route choice path and sp
30. 9 Yes 4 00 4 99 Yes more than 5 00 Un boarding airplane rail intercity Pick up Drop off 1 activity sub category l 2 Working at home Travel Did you pay a toll on 3 Shopping at home your trip 4 SE at home d Get on vehicle Wait for a ride Is there a change of 5 Leave Park a vehicle No Boarding airplane rail intercit drivers 6 bus g p y Number of person s Yes prepaid 7 8 a 10 7 Pick up Drop off Are you the driver or a Welcome to the passenger Automated Travel Diary Thank you Have a safe trip Pick up someone Drop off someone 1 2 3 4 5 6 T 8 Get picked u 9 Passenger What is your trip Get eae a d ww or more d Continue traveling Driver Begin a new trip activity Stop traveling u d Home 1 IT Please select a trip u 4 Travel SA ce 4 4 Pick up Drop off activity en Work l selget transit type m Education childcare Work include scheduled and Were there any parking Dining volunteer work cost on your trip Local bus Recreation entertainment Work related meeting errand Pl
31. AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology PERSON INFORMATION Table 2 continued Pre Entered Data Person X Race Indicate all that this person considers himself herself to be E White alone but not Hispanic gt E 2o spam ooo E 3 Black or African American alone mE 4 Asian alone Asian Indian Chinese Filipino Japanese Korean NONE 1 Vietnamese Other Asian ee 5 Native Hawaiian or other Pacific Islander alone 1 KNEE American Indian or Alaska Native alone 1 1 B 7 Otherrace alone specify during interview E 98 2 Combination of two or more of the above categories 1 E 99 DontKnow Refued 1 1 Person X Education Highest level of education completed 5 1 No schooling completed 000000 B 2 Rdursryschoo Preschol eee 35 Kindergarten n 4 Actual Grade ltoGradel2 1 RENE High school graduate eee E 8 Some college no degree 10 iUndergrduateBachelors degree B ll Some graduate school no degree n 12 Master s degree 5 13 Professional degree ea 5 l4 ooo Doctorate or higher dgree eee 99 Don t Know Refused 5 i Nursery school Prescho 0 t 2 Kindergarten oo 3 Actual Grade I to Grade 12 6 College undergraduate years fre
32. ATD also fits well in shirt and jacket pockets as well as hand bags Thus survey respondents may carry it in all modes of transportation Moreover the initial GPS ATD menu requires fine tuning to improve ease of use For example the initial menu structure does not allow for respondents to change their mind regarding their destination and trip activity type in the middle of the trip a Figure 32 GPS ATD on a bicycle mount 69 Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology Figure 34 Trip information displayed in Google Earth example short trips often not reported 70 Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology CHAPTER 8 CONCLUSIONS AND FUTURE WORK The goal of this development was to create an information gathering system which in the end will provide the highest quality data for purposes of analysis and model creation This report provides background and technical tradeoff information functional requirements and specifications and a design and prototype development that best supports future travel behavior surveys The GPS ATD is a highly integrated and custom designed system with HSGPS as its core component technology Two GPS ATD versions vehicular and personal have b
33. Assembled GPS ATD circuit board top side 2 0000000000000000000000000000sssnnnnnnnunnnnsssssssssnnse 59 Figure 21 Assembled GPS ATD circuit board bottom side ecce eere ee eere een 59 Figure 22 GPS ATD circuit board bottom and top stencil 2 000000000000000000000000000000000nsnnnnsnnsssssssnnnse 61 Figure 23 GPS ATD circuit board fixture for applying RoHS solder paste 61 Figure 24 Fully assembled GPS ATD bottom side circuit boards qty 10 shown 62 Figure 25 Fully assembled GPS ATD unit internals 20000000000000000000000000000000000000000000000000000000000000000 62 Figure 26 GPS ATD firmware architecture 0000ooooo000000000000000000000000000000000000000000000000000000000000000000000 63 LEisire27 GPS ATD User inter ace oni eibi ei EIE EOS LOD 65 Fiseure 28 Personal GPS A TD ennn ii Pi Re 67 Figure 29 Personal GPS ATD with optional patch antenna eee ee eee eee eee eee eee eee ee eee e sans 67 Figure 30 GPS ATD battery charging curve eeoooooooooooooooooooooo0o0ooooo00000000000000000000000000000000000000000000000 68 Figure 31 GPS ATD battery discharging curve 22000000000000000000000000000000000000000000000000000000000000000000000 68 Figure 52 GPS A TD n bicycle HOME od a aa Oo wawa ao 69 Figure 33 Trip information displayed in Google Ear
34. California AHMCT Program University of California at Davis California Department of Transportation DEVELOPMENT OF VEHICULAR AND PERSONAL UNIVERSAL LONGITUDINAL TRAVEL DIARY SYSTEMS USING GPS AND NEW TECHNOLOGY Kin S Yen Stephen M Donecker Kimball Yan Travis Swanston Ayalew Adamu Leo Gallagher Mohammad Assadi Bahram Ravani amp Ty A Lasky Principal Investigator AHMCT Research Report UCD ARR 06 12 31 01 Final Report of Contract RTA65A0189 December 31 2006 Affiliations 1 AHMCT Research Center Department of Mechanical amp Aeronautical Engineering University of California Davis CA 95616 2 Caltrans Division of Transportation System Information 1120 N Street MS 38 Sacramento CA 95814 This report has been prepared in cooperation with the State of California Business and Transportation Agency Department of Transportation and is based on work supported by Contract Number RTA 65A0189 through the Advanced Highway Maintenance and Construction Technology Research Center at the University of California at Davis Copyright 2011 AHMCT Research Center UC Davis Copyright 2011 AHMCT Research Center UC Davis Technical Documentation Page 1 Report No 2 Government Accession No 3 Recipient s Catalog No F CA IR200645 4 Title and Subtitle 5 Report Date GPS and New Technologies to Improve Longitudinal Travel December 31 2006 Surveys 6 Performing Organization Code 7 Author s Kin
35. Center UC Davis Copyright 2011 AHMCT Research Center UC Davis GPS Automated Travel Diary User Guide SECTION 4 BASIC OPERATION FOR USERS In a typical trip there are two sets of questions to be answered The first set of questions should be answered right at or before the beginning of a trip The second set of questions is to be answered at the end of the each leg of a trip At the beginning of each trip the user survey respondent should select Begin a new trip by pressing the OK Select button After that the user will enter the mode of travel and or the trip activities purpose User should follow the menu and answer each question displayed The number of questions varies from 3 to 7 depending on the selected answers and options Below figures shows a typical trip menu flow 11 Copyright 2011 AHMCT Research Center UC Davis GPS Automated Travel Diary User Guide Ze Are you the driver or a passenger m Dec 29 9 21am Number of passengers including yourself 12 Copyright 2011 AHMCT Research Center UC Davis GPS Automated Travel Diary User Guide Incidental eat drink ATM bank post office The following display marks the end of the first set of questions to be answered at the beginning of the trip The user should not answer this question until the end of this leg of the trip This menu structure is designed to trap any accidental button pressing
36. Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology Table 1 Fixed static information collected in a travel survey Information Categories Specific information Houschold Information Vehicle details vehicle type fuel type ownership etc Household Member Personal Information Table 2 Dynamic travel diary information collected for given trip s Category Data Element Sub Element Activity Type of activity Start time End time Origin location Destination Travel Mode Switching travel mode Reason of mode choice Personal Vehicle Vehicle used Driver or passenger Vehicle occupancy Parking cost Other toll costs Distance OBD II data Transit Transit fare Location of access Location of egress Wait time Number of transfers Distance Bicycle Use of bicycle lanes Distance Means of securing bicycle at destination 21 Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology Table 3 Summary of previous travel surveys Location Year Duration Sample Size Survey Methods Z mec 35 149 ma MEN ae PAPI Lexington KY mE l Er s 100 households Vehicle only GPS PDA with 2 3 sec sampling period California 2000 Oct 2000 and Dec 58 counties and 17 040 Computer Assisted 2001 2001 one 24 hr households Telephone Interview w
37. M processor based on a 1 8 V memory bus were selected with the CPU core requiring a 1 5 V rail The processor data bus connected to the 256 MB NAND Flash device was also 1 8 V therefore the optimal design used a 1 8 V NAND Flash device Part availability in both small and large quantity 1s a major issue especially if the part is new or being used in popular devices such as PDA portable GPS navigation devices and MP3 players A new part may not be up to full production for months after the manufacturer s announcement of availability The resulting short supply is often sold before manufacture and often the minimum order is 10 000 units or more Larger customers are given preferential treatment and higher shipment priority on available stocks In some cases large customers may have exclusivity with the component manufacturer For example the proliferation of pocket electronics has put an enormous load on the NAND Flash industry so that it s virtually impossible for prototype developers to obtain any current generation Samsung Flash devices Despite Samsung s superior Flash specification the only option left is to design using previous generation parts at higher cost larger package size higher power requirements and more associated glue circuitry Availability changes with market conditions and industry trends which led to design changes throughout the project for certain major components Finally the selected components must be compatible
38. MCT Research Center UC Davis Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology CHAPTER 3 SYSTEM OVERVIEW OF THE GPS AUTOMATED TRAVEL DIARY Automation is the key to reduced respondent burden and increased accuracy and data integrity To lower the cost weight complexity and power consumption of the GPS Automated Travel Diary GPS ATD its required tasks should be minimized Therefore longitudinal travel surveys should be divided into two phases as shown in Figure 5 data collection and data post processing The GPS ATD should collect all necessary raw data leaving further processing for the subsequent data post processing and analysis phase Researchers and analysts may then process and re process the raw data with various criteria methods and GIS information updates in the post processing phase Phase I Data Collection Phase Il Post Processing T 1 Data Visualization TL N s j GPS ATD X Vehicular Ta X Units e E e e E XML DBF ata In TXT etc Analysis ER Data Bo Format Conversion n f r E GPS ATD Personal T GIS Database nits e9 x E A A Th P ES Figure 5 System architecture including data collect
39. No Welcome to the Coaster What is the purpose of Yes prepaid Automated Travel Diary SAB use o GU red Ferry your trip From No Yes less than 1 00 Metro Blue Line Pick up someone Yes 1 00 1 99 Auto truck van diete Gus Line P Home Drop off someone Have you stopped Yes 2 00 2 99 Public transit Metro Red Line Work place Get picked up Yes 3 00 3 99 Other BART Work related Get dropped off Begin a new trip i Yes 4 00 4 99 u d s Metro Link Social or entertainment s d Ho SR pee Yes 5 00 9 99 Heavy Rail Caltrain Recreational parks etc Ms g MR s E Yes 10 00 14 99 Yes This is my final destination Amtrak Shop Yes 15 00 24 99 n an transit UN 1 87 h u Yes 25 00 29 99 If answer is No and Chool related Dus er Yes more than 30 00 previous mode is por u Sup ce u Auto truck van eer u d ick up Drop o 1 5 2 4 3 21 26 4 a gt p gt Select type 5 T Your trip is finished Thank Are you changing your 6 Mie ae Did you pay fare on this you for your cooperation model of travel On foot 7 mos A m trip Bicycle 8 imo or Intercity bus ok Motorcycle moped 9 No Taxi shuttle bus limo 10 or more Yes prepaid Yes Intercity bus Greyhound etc u 4 a R than 5 00 u 4 d Airplane commerical ye 5 00 9 99 Airplane private Yes
40. PS receiver test results 47 Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology As such we selected a SIRF III based GPS chipset module to be incorporated in the GPS ATD design based mainly on ts urban canyon and underground parking structure performance Note that several new GPS receiver chipsets became available twelve months after our GPS testing but too late in the GPS ATD development cycle According to www gpspassion com users found that MTK chipset based GPS units perform as well as the SiRF III chipset and in some cases better The MTK GPS chipset also consumes 50 less power than SiRF III In addition there is now a low power version of the SiRF III chipset which consumes half the power of the previous version Thus the GPS ATD battery run time may be further extended using the new low power MTK or SiRF III modules However these new generation modules were not available until the current project s development was complete GPS Antenna Test Results The Sarantel GeoHelix antenna is a new generation of GPS antenna designed specifically for handheld device applications It offers several advantages over a traditional patch GPS antenna compact size omni directionality light weight and less susceptibility to interference by the human body and hand 16 Both the Sarantel GeoHelix and a patch antenna were connected to
41. RF II SIRF III and Sony GPS receivers number on symbol indicates number of satellites used for position calculation 45 Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology The remaining systems were tested n the basement and first levels of a parking structure The SIRF III was the only GPS that continuously tracked GPS signals and provided good positional solutions in both the first and basement levels of the parking structure Other GPS modules generally lost track and could not provide solutions midway into the parking structure Moreover the remaining GPS were tested in an urban canyon environment specifically downtown Sacramento California The SiRF III was the only GPS that could continuously provide solutions Other GPS modules would lose track near tall buildings ld if C WEEK By T TOW die M ed ma Lond T la dm EET FETTE 5 A AS ha AA g ren 0 sape E ER ege ccs L M M ww vw E I a am x a are m a Figure 10 Parking structure GPS receiver test results in the basement level 46 Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology RR a zam e a o RR 4 gocsssm Figure 12 Downtown Sacramento G
42. S low cost small Micro Electro Mechanical Systems MEMS inertial sensors low power embedded computers high capacity storage devices wireless communications and high speed Internet have converged to make a portable and low cost data collection system a feasible reality Each of these technical areas will be discussed in detail in this chapter Current Global Positioning System GPS Status The Global Positioning System GPS is a space based radio navigation system consisting of a constellation of satellites and a network of ground stations used for monitoring and control A minimum of 24 GPS satellites orbit the Earth at an altitude of approximately 11 000 miles providing land sea and airborne users with accurate information on position velocity and time anywhere in the world and in all weather conditions with precision and accuracy far better than other radio navigation systems available today or in the foreseeable future see http gps faa gov Currently there are 30 operational GPS satellites 1n orbits They circle the Earth twice per day The space and ground control GPS segments are operated and maintained by the Department of Defense DOD In 1996 a Presidential Decision Directive later passed into law transferred ownership from DOD to an Interagency GPS Executive Board IGEB co chaired by senior officials of the Departments of Transportation and Defense to provide management oversight to assure that GPS meets both civil a
43. S ATD in a bathtub or shower e Do not interact with the GPS ATD while walking driving a vehicle riding a motorcycle or riding a bicycle You may fall or cause a traffic accident possibly resulting in serious injury e If you notice leaking fluid or odor from the GPS ATD immediately move the GPS ATD away from any source of fire The fluid from the GPS ATD is leaking from the built in battery In the event of battery leakage the fluid may ignite and cause an explosion possibly resulting in serious injury 111 Copyright 2011 AHMCT Research Center UC Davis GPS Automated Travel Diary User Guide e If you discover leakage from the GPS ATD do not touch the fluid The leakage from the GPS ATD is fluid from the built in battery Battery fluid contacting the eye or the skin can result In serious eye injury or skin damage If battery fluid enters your eye rinse your eye thoroughly with clean water and seek immediate medical attention If battery fluid should contact your skin or clothes immediately rinse it away with clean water and seek immediate medical attention e Do not charge or discharge the GPS ATD near fire or under the hot sun The built in battery may leak causing fire or explosion possibly resulting in serious injury e Do not place the GPS ATD in a hot location Placing the GPS ATD under direct sunlight near a stove etc can result in heat generation or fire possibly resulting in serious injury e Do not subject t
44. T Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology PERSON INFORMATION Table 2 Pre Entered Data Code Specific Information Person X Name First Name Middle Initial Person X Sex Ls l Male L 2 Female 99 Refused Person X Age Ordinal Variable 1 97 Actual Age If less than one year of age enter 1 98 Age 98 99 Don t Know Refused Annual Person Income Wages salary commissions bonuses or tips from all jobs Report amount before deductions for taxes bonds dues or other items 4 35 000 49 999 6 75 000 99 999 8 150 000 199 999 9 200 000 99 Don t Know Refused Person X Relation to the Head of Household Self Spouse Partner Son Daughter includes Stepchildren Mother Father Mother in Law Father in Law Other relative Not related Don t Know Refused Residence During the Year How many months a year do In Less than one month _ One or more months Ordinal Variable Reason for Residence What is the main reason members of this household stay at the address given for the household E l This is their permanent address E z This is their seasonal or vacation address E To be close to work 4 To attend school or college 82 Strikethrough are confidential fields Copyright 2011
45. aa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa aaa 33 Wireless Technology Developments ak AAAA AGO 33 Chapter 3 System Overview of the GPS Automated Travel Diary 35 Recommended GPS Aided Electronic Travel Diaries Systems 35 System Implementation au 38 Desin TV AGC OES m M 41 Chapter 4 Component Testing and Evaluation eee e eee eee eere eene eene 43 GPS Sensor Test Results zes kai a 43 GPS Antenna Test Results eite 222 aa 48 GPS Antenna Placement SimulationsS 22200000000000000000000000000000000000000000000000000000000000000 48 Chapter 5 Hardware Design and Implementation e eeee ecce eere eere 51 Circuit Board DOSIER er RE ER Fe 56 GES ATD M anufacturine i GO A T 60 Circuit Board Assembly Piocess a 2er 60 Chapter 6 GPS ATD Firmware idee e eer a 63 User ilio ulum M Ee 64 vil Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology Chapter 7 GPS ATD Testing and Evaluation e eee esee eee eene eerte 67 Chapter 8 Conclusions and Future Work cc eeee esee ecce eee eee eene eee ene 71 Recommendation for Future Research 4 ee ee eee eee eee e e eese eene ee eese eee oeste eoe 71 Refren OS oane TETTE C
46. ailure to provide power 3 24 Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology Respondents not carrying the unit due to o Weight and size 8 o Difficult to carry when bicycling 1 e Software bugs 1 e Inability to differentiate vehicle stop at the end of a trip vs a stop caused by congestion or pedestrian crossing 3 29 e Loss of GPS signal due to urban canyons improper GPS antenna orientation on the respondent body and signal blockage inside vehicles such as buses 1 6 e and loss of GPS data during GPS receiver cold start period 6 7 Nevertheless the GPS aided electronic travel diary has the strongest potential to fully capture all travel behavior exactly for accurate modeling The drawbacks of previous GPS aided travel diaries and loggers have been overcome in the current project s GPS ATD system by tight component integration additional sensors longer lasting backup batteries and increased onboard processing power and intelligence 25 Copyright 2011 AHMCT Research Center UC Davis Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology CHAPTER 2 RECENT EMERGENCE OF SUPPORTING TECHNOLOGIES Recent technological developments and improvements in the Global Positioning System GP
47. ate attention must be applied to the design and isolation of the various RF circuits from the rest of the system components Noise may come in from of conducted noise through the power supply rails and ground planes as well as radiated noise through coupling of adjacent circuit traces The supply rails must be adequately filtered so that existing noise does not modulate into the signal path and so that RF energy doesn t travel to the supply rails 53 Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology This may be accomplished by inductive components and traces supplying the voltage to the LNAs In the GPS ATD design a two stage LNA was created and placed in front of the SiRF III based GPS receiver module Our front end used good RF design techniques to match to the Sarantel antenna and GPS receiver while maximizing gain and minimizing noise figure Currently the GPS module power supply is isolated from the main system power supply using a bypass capacitor A better design would include a series inductor to the GPS module power supply input A ZigBee transceiver was implemented to enable wireless communication between personal and vehicular GPS ATD and the ZigBee OBD II reader Initially a fully integrated single chip Chipcon ZigBee CPUttransceiver design was selected However availability forced redesign using the previous generatio
48. avigation method used in ships aircraft and more recently mobile robots Essentially it is used to estimate an object s position based on the distance traveled in the current direction from its previous position A simple dead reckoning system measures acceleration and angular rates and estimates heading and speed then integrates to obtain position For a vehicle heading could be measured by compass and or gyro and the speed may be obtained through accelerometer or wheel rotational speed DR will provide position information if GPS is not available for a short period of time Since DR relies on integration of sensor measurements error increases as usage duration increases this s referred to as drift The error can be corrected with a positional update from the GPS receiver Traditionally DR is used to estimate current position based on previous position in time However a non causal technique can be used to back calculate to obtain a previous position based on the current position given by the GPS receiver Thus during post processing the user position can be determined during the long GPS cold start up time if the system logs inertial data Small and low cost MEMS gyro and accelerometer chips see e g Figure 4 available today make low cost DR possible In addition MEMS gyros and accelerometers can measure vehicle acceleration detect lane changes and provide dead reckoning to increase GPS availability in a complementary fashion Combini
49. beginning of a trip The second set of questions is to be answered at the end of the each leg of a trip At the beginning of each trip the user should select Begin a new trip by pressing Vv After that the user will enter the mode of travel and or the trip activities purpose The user should follow the menu and answer each question The number of questions varies from three to seven depending on selected answers and options Detailed GPS ATD operation is provided in the GPS ATD user guide which can be found in the appendix along with the GPS ATD menu structure 64 Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology GPS AID Battery GPS Up OK Select Status Area Status Status Date Time Key Key GPS Antenna i N ie 191 Li Vee Menu Selection Area LCD Back Cancel Ke Down Selection is highlighted Display Key Figure 27 GPS ATD user interface 65 Copyright 2011 AHMCT Research Center UC Davis Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology CHAPTER 7 GPS ATD TESTING AND EVALUATION The prototype boards performed as designed with respect to timing All high speed circuitry worked flawlessly However the system power noise was higher than predicted based
50. ber of passengers vehicle type fuel type and identity of the driver cannot be determined without the input of the respondents or an image of the vehicle interior Replacing traditional self administered paper travel diaries with interactive GPS aided travel diaries has shown significant reduction in the resulting respondent burden Battelle reports that 75 of respondents took less than one minute to enter all required trip information into an interactive electronic travel diary 1 On the other hand respondents would generally spend 10 minutes on a paper diary or 20 25 minutes on a follow up phone call Therefore a GPS aided interactive travel diary could save both surveyors and respondents time and money Previously all GPS aided travel surveys were performed on a relatively small scale sample size lt 300 Moreover all GPS aided electronic travel diary devices were developed by loosely integrating commercial off the shelf items Typically a GPS receiver was connected to a data logger or a Personal Digital Assistant PDA hand held computer 1 3 6 8 29 32 Data were entered using touch screen or keypad interfaces Each device had its own power source These GPS travel diary data loggers used in previous surveys have their drawbacks A high percentage of the units failed to achieve full data collection capability due to e Hardware failure o Broken cable connection between the GPS and the data logger or PDA 1 32 o Respondent f
51. bus Yes less than 5 00 O ve Airplane private ATM banking post office Yes 5 00 9 99 gt O her GE D Yes 10 00 14 99 V Don t know refuse p u 4 Yes 15 00 19 99 Er z Yes 20 00 24 99 Ec lt Yes 25 00 29 99 49 If answer is No and previous mode is not Auto truck van Yes more than 30 00 If final destina ion u d Q is no 25 Copyright 2011 AHMCT Research Center UC Davis GPS Automated Travel Diary User Guide GPS ATD Hybrid Mode Menu Flowchart If mode selection is Auto truck van Motorcycle or Other Are you the driver ora Number of passengers wikt O Uns eme e GU Devo pavo your trip To your trip passenger g including yourself Thank you Have a safe Driver 1 Home trip Nlo Work place i 28 Passenger A Work acd Continue traveling ur ARNE 1 00 48 4 Social or entertainment Stop traveling Yes 1 00 1 99 Is there a change of 5 Recreational parks etc Yes 2 00 2 99 drivers 6 Shop d Yes 3 00 3 99 7 School Yes 4 00 4 99 No 8 Other Yes more than 5 00 Yes 9 S Select transit type 10 or more u 4 Were there any parking cost on your trip 24 Local bus 4 Express commuter bus Light rail street car trolley Are you picking up or Cable car Dropping off person s
52. ck line includes LPV a b Color Scale is Vertical Protection Level VPL 15 Nov 2004 13 00 15 WJH FAA Tech Grir MI USA ia i 180 160 140 120 100 50 VPL W J H FAA Technical Conder Longitude 5 degree sample size meters RVG Test Team LRL ES Figure 2 WAAS GPS vertical accuracy map http www nstb tc faa gov vpl html 29 Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology GPS Vulnerability Many factors can degrade GPS performance GPS receivers require a direct line of sight to the satellites in order to obtain a signal representative of the true distance from the satellite to the receiver Therefore any object n the path of the fa rly weak GPS signal has the potential to interfere with its reception Objects which can block a weak GPS signal mclude tree canopies buildings and terrain features Similarly the WAAS geostationary satellite signal can also be blocked Furthermore reflective surfaces can cause the GPS signals to bounce before arriving at a receiver thus causing an error in the distance calculation This problem known as multipath can be caused by a variety of materials including water glass and metal Even the water contained in the leaves of vegetation can produce multipath error In some instances operating under heavy and wet forest canopy can degrade the abilit
53. creation of the Global Positioning System Automated Travel Diary GPS ATD The authors gratefully acknowledge the Division of Research and Innovation of Caltrans which has supported this work through the AHMCT Research Center at the University of California Davis under contract RTA65A0189 The authors also thank the GPS ATD development team in the AHMCT Research Center Stephen M Donecker Kimball Yan and Travis Swanston Finally the authors thank the Caltrans Division of TSI team members Coco Briseno the current Division Chief of TSI Robert Copp the former Division Chief of TSI David Saia the former Chief of the Office of Travel Forecasting and Analysis Frank Law Chief of the Statewide Modeling Branch Leo Gallagher Mohammad Assadi Azita Fatemi Gregory Miyata Soheila Khori and Diana Portillo XVII Copyright 2011 AHMCT Research Center UC Davis Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology CHAPTER I INTRODUCTION AND BACKGROUND This chapter provides a brief introduction to objective longitudinal traveler surveys including previous methods of conducting surveys and their findings The objectives are to e Summarize travel survey goals and define the data needed for travel demand forecasting e Identify the challenges inherent in longitudinal travel surveys and pitfalls encountered in previous GPS aid
54. ction Identify types of household travel survey respondents who are representative of the target population by age group language ethnicity and technological skills for the use of GPS device Classify survey participants by their capabilities and limitations to understand and use either the simple or more sophisticated GPS device Rank the GPS devices from high to low according to the literacy and technological skills required to operate these GPS devices within the parameters of the survey For highly skilled respondent a more sophisticated GPS device may be needed For participants with the lesser technological skills a totally automated GPS device which requires minimum respondent interaction may be appropriate In summary prepare a report on GPS selection criteria and recommended GPS application by various household types b Develop protocols for collection and analyses of multi modal trip data for multi day longitudinal household travel survey 1 Develop methodologies for downloading and processing trip data Provide GPS data output that 1s readable by GIS software 3 Identify multi modal trips and develop a method on how to combine all legs of the multi modal trip information 4 Develop Methodology on how to identify linked trips e g change travel mode drop off or pick up passenger c Identify Trip Route from GPS data d Develop guidelines to collect long distance trips for the statewide modeling by trip pur
55. ctivity 2 UN On foot sub category Personal Did you pay fare on this 6 Bicycle 17 trip Motorcycle moped VT Fueling vehicle Are you changing your y model of travel Taxi shuttle bus limo uee Nel neee If mode selection is Public No Intercity bus Greyhound etc Incidental eating drinking coffee Transit Taxi shuttle Yes prepaid ae No Airplane commerical Major shopping limo or Intercity bus Yes less than 5 00 O ve Airplane private ATM banking post office Yes 5 00 9 99 gt O her GE D Yes 10 00 14 99 V Don t know refuse p u 4 Yes 15 00 19 99 Er z Yes 20 00 24 99 Ec lt Yes 25 00 29 99 49 If answer is No and previous mode is not Auto truck van Yes more than 30 00 If final destina ion u d Q is no 25 Copyright 2011 AHMCT Research Center UC Davis GPS Automated Travel Diary User Guide GPS ATD Hybrid Mode Menu Flowchart If mode selection is Auto truck van Motorcycle or Other Are you the driver ora Number of passengers wikt O Uns eme e GU Devo pavo your trip To your trip passenger g including yourself Thank you Have a safe Driver 1 Home trip Nlo Work place i 28 Passenger A Work acd Continue traveling ur ARNE 1 00 48 4 Social or entertainment Stop traveling Yes 1 00
56. d during the reflow process In addition it is vital that an appropriate amount of lead free solder paste is applied preferably using a laser cut mask as shown in Figure 22 Circuit Board Assembly Process The bottom side of the GPS ATD circuit board 1s assembled first in part because the components and assembly are less sensitive to the second reflow for the top side After testing and validation of the power supplies of the fully assembled bottom circuit the top side 1s then assembled The assembly process for both board sides 1s very similar First the proper amount of lead free solder paste 1s applied to the soldering area of the circuit board with time and labor significantly reduced using the laser cut stencil shown in Figure 22 A CNC computer numerical control machined fixture shown im Figure 23 was used to hold the circuit board in a fixed position relative to the stencil After the board is placed into the fixture the stainless steel stencil is placed on top Solder paste is then spread across the stencil surface Next the stencil 1s carefully lifted and the circuit board 1s removed from the fixture Each part 1s then hand placed onto the circuit board Finally the fully populated board is baked inside a reflow oven following a precise temperature profile This process is repeated for the top side of the circuit board Each fully assembled board shown n Figure 24 and 25 then goes through a board validation process The GPS an
57. data stored in an efficient binary format in flash The other sensors are adaptively sampled as required with the resultant data also stored in binary format for optimal memory use The wireless interface is based on the familiar ZigBee technology and is used for data transfer and unit to unit communication The user interface 1s based primarily on a 160x240 resolution LCD graphic display with backlighting and automatic contrast control to ease user burden In the case of the portable device the system 1s powered by a Lithium Ion polymer battery and has a built in charger The system can be charged by a power supply in a manner similar to cell phones Preliminary tests suggest that the portable system should be able to run for eight hours continuously when the user device is at rest or 1s riding in a car with a vehicle system already gathering data Table 1 GPS ATD System Hardware 200 MHz 32 bit ARM 32 MB SDRAM 256 MB Wireless Sirf IN Vehicle Interface OBD II 2 G max with 5 mG resolution 75 deg sec max 160x240 backlit automatic contrast User Interface control 4 application specific buttons Li lon polymer battery Power Switching supply Built in charger and battery protection 21 Copyright 2011 AHMCT Research Center UC Davis GPS Automated Travel Diary User Guide Table 2 Comparison of Vehicular and Personal Versions of the GPS ATD Data ersonal Identity rip Purpose ravel Begin Time ravel End Time Vehicular Ve
58. ds and reduce the likelihood that loss of GPS data occurs at the beginning of a trip due to potentially long GPS cold start time Moreover the MEMS inertial sensor data is also collected and stored in solid state memory The vehicular GPS ATD can determine the starting and shutting off of the vehicle by monitoring the power input voltage and via other means Typically a vehicle s 12 Volt source will have a voltage greater than 13 Volts when the engine is started Thus the vehicle stopping at the beginning and end of a trip can be easily separated from traffic Jam stops or stops at rail and pedestrian crossing Finally the vehicle system contains an interface to the OBD II port on all new vehicles 1996 and later The OBD II interface provides access to vehicle telemetry and diagnostics to determine vehicle speed engine characteristics and dynamic emissions The features of the two GPS ATD versions are compared in Table 6 37 Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology Table 6 Comparison of vehicular and personal versions of GPS ATD Data ersonal Identity rip Purpose ravel Begin Time ravel End Time Vehicular Ver Personal Ver rip Distance by GPS ost of Tr p fees parking toll etc OFA SSS zi D gt e amp Un ko C I r 6 g lt eo y un witching Mode of T
59. e after Yes 2 00 2 99 Public transit Ferry activity RA i C care Yes 3 00 3 99 Other Metro Blue Line LIS Yes 4 00 4 99 u Metro Green Line Eat out restaurant etc Yes 5 00 9 99 Metro Red Line Drive Through 146 Yes 10 00 14 99 BART Please select a trip activity 7 Have you stopped Yes 15 00 24 99 9 If answer is No and previous Metro Link sub category Yes 25 00 29 99 mode is Auto truck van Heavy Rail Caltrain 1 Recreation Entertainment No Yes more than 30 00 Amtrak IT Please select a trip activity l Fitness ac ivities gym sports Yes I m making a stop 4 ARA WE sub category Vaca ion sightseeing camping etc Yes This is my final destination sine were bus 4 Social Civic Religious Movies dancing spectator sports Your trip is finished Thank TEE t u 4 you for your cooperation 5 Visit friends rela ives u d N Community mee ings public event etc If answer Select type Occasional volunteer work 1 67 T uz is yes Religious gathering 4 Please select a trip activity 2 UN On foot sub category Personal Did you pay fare on this 6 Bicycle 17 trip Motorcycle moped VT Fueling vehicle Are you changing your y model of travel Taxi shuttle bus limo uee Nel neee If mode selection is Public No Intercity bus Greyhound etc Incidental eating drinking coffee Transit Taxi shuttle Yes prepaid ae No Airplane commerical Major shopping limo or Intercity
60. e located n the appendix 15 Copyright 2011 AHMCT Research Center UC Davis Copyright 2011 AHMCT Research Center UC Davis GPS Automated Travel Diary User Guide SECTION 5 DOWNLOADING DATA Travel Survey Respondents GPS ATD logged data are vigorously protected and may not be downloaded by end users or any unauthorized person Authorize GPS ATD Administrator GPS ATD logged data are vigorously protected and may only be downloaded by an authorized administrator using special software and password through the USB port See data download software Instructions for further detail 17 Copyright 2011 AHMCT Research Center UC Davis Copyright 2011 AHMCT Research Center UC Davis GPS Automated Travel Diary User Guide SECTION 6 FREQUENTLY ASKED QUESTIONS TBD Copyright 2011 AHMCT Research Center UC Davis Copyright 2011 AHMCT Research Center UC Davis GPS Automated Travel Diary User Guide SECTION 7 SPECIFICATIONS Table 1 shows the hardware specification The Central Processing Unit CPU is a 32 bit 200 MHz ARM chip This chip runs the embedded Linux operating system OS At boot up the program stored in the on chip flash will be loaded into the 32 Megabyte MB Synchronous Dynamic Random Access Memory SDRAM for execution The internal 256 MB non volatile flash stores the survey data GPS menu choices and related In general the GPS data sampled and parsed once per second 1 Hz with the pertinent
61. ease select a trip Express commuter bus Social civic religious ete 4 activity sub category No Select mode of travel Light rail street car Personal Education childcare Yes prepaid trolley School preschool K 12 grade Yes less than 1 00 Cable car Medical E School college or vocational p gt Yes 1 00 1 99 Auto truck van Coaster Other out of home ac ivity lease select a trip 3 Childcare day care before after Yes 2 00 2 99 Public transit Ferry activity RA i C care Yes 3 00 3 99 Other Metro Blue Line LIS Yes 4 00 4 99 u Metro Green Line Eat out restaurant etc Yes 5 00 9 99 Metro Red Line Drive Through 146 Yes 10 00 14 99 BART Please select a trip activity 7 Have you stopped Yes 15 00 24 99 9 If answer is No and previous Metro Link sub category Yes 25 00 29 99 mode is Auto truck van Heavy Rail Caltrain 1 Recreation Entertainment No Yes more than 30 00 Amtrak IT Please select a trip activity l Fitness ac ivities gym sports Yes I m making a stop 4 ARA WE sub category Vaca ion sightseeing camping etc Yes This is my final destination sine were bus 4 Social Civic Religious Movies dancing spectator sports Your trip is finished Thank TEE t u 4 you for your cooperation 5 Visit friends rela ives u d N Community mee ings public event etc If answer Select type Occasional volunteer work 1 67 T uz is yes Religious gathering 4 Please select a trip a
62. ed for position calculation 45 Figure 9 UC Davis parking Structure ai 1r otia dw add Lobo Co edos raiot i orias 46 Figure 10 Parking structure GPS receiver test results in the basement level 46 Figure 11 Parking structure GPS receiver test results in the first level 47 Figure 12 Downtown Sacramento GPS receiver test results eee e ecce eee eee ee eee eee eee eee eesos 47 Figure 15 Sarantel GeoHelix GPS antenna aiii hoop eoi ber dada L ALEZ 48 Figure 14 Simulated effect of placing the GPS antenna on the dashboard vs on the roof No blockage line represents GPS antenna on the vehicle roof and the others represent GPS antenna on the vehicle dashboard traveling in various directions 49 Figure 15 GPS ATD system block diagram sseoooooo000000000000000000000000000000000000000000000000000000000000000000000000 32 Figure 16 GPS ATD membrane switch user keypad sssooooooooooooooooooooo0000000000000000000000000000000000000000 55 Figure 17 All layers and layer 3 of the GPS ATD circuit board ssoooooooooooooooooooooooooo0000000000000000000 56 Figure 18 Layer 4 and layer 5 of the GPS ATD circuit board 222222 00000000000000000000000000000000000 56 Figure I9 GPS ATD circuit board een 58 Figure 20
63. ed longitudinal travel surveys e Summarize previous major travel surveys e Highlight the reference research and literature In addition details of GPS and other relevant new technological developments are provided The authors recommend review of all the cited references to gain a deeper understanding The aim is to illuminate the key findings of the past research to foster ongoing discussion and understanding of the context and need for the GPS Automated Travel Diary GPS ATD Longitudinal Traveler Survey and Demand Forecast Modeling There is a need for finer grained understanding of traveler behavior than current data collection techniques allow Traditional cross sectional survey methods are somewhat coarse and seek to provide traffic measurements for a single point of a road or intersection thus providing traffic loading at a specific location over time While this may support conclusions regarding the capacity of a particular location it does not provide needed information on traveler behaviors such as trip purpose trip frequency and schedule route selection and speeds used throughout the entire route Many factors can contribute to a driver s reasons for choosing a particular route A system which can monitor current traveler location time speed and current and next tasks is required Longitudinal surveys directly measure traveler behavioral change at the level of the individual traveler and provide information that can lead t
64. eed profile information items not feasible with traditional paper surveys 7 23 These data may be used to measure the level of congestion of a particular highway 2 27 GPS travel diaries used in the past may be classified into two types interactive and passive 6 28 An interactive electronic travel diary requires the respondent to interact with the hand held computer to input survey Information such as marking trip start and end trip purpose cost of trip and travel mode A passive travel diary requires essentially no interaction with the respondent respondents only need to carry and turn on the device whenever they travel Other essential trip information is collected through paper survey or follow up phone call or s estimated by computer aided software based on the GPS data Passive travel data loggers have been used to determine a Trip Underreporting Correction Factor TUCF which was used to adjust the statistical results of a larger sample paper survey 3 35 Some methodical GPS data post processing approaches have been developed to successfully extract temporal trip start and end trip purpose and travel mode from the passive GPS data collected 3 6 28 32 35 Determining the cost of a given trip from GPS data was not done in previous research However toll and parking costs could be extracted based on the vehicle route and stop duration if detailed toll and parking fee structures in the traveled area are known Nevertheless the num
65. eekday one 48 CATI on all respondent hr weekend 20 and passive GPS weeks with monitoring on 292 passive GPS households Used GPS to logger determine underreporting factor Atlanta Georgia 2000 5 days 250 households with All methods were Electronic Travel Diary used 33 ETD amp GPS 50 households with ETD GPS amp OBD I 250 households with passive GPS Mobidrive Spring amp 6 weeks 362 persons in 162 Paper and Pencil Germany Fall households Interview PAPI 1999 Swedish 80 weeks 186 vehicle and 49 667 Passive GPS with vehicle Intelligent Speed 2000 to vehicle days engine on off sensing Adaptation Borlange Lund and Lidkoping Puget Sound July amp 48 hrs 6 000 households Paper and Pencil Household Nov Interview PAPI Travel Survey 1999 Previous longitudinal surveys have shown that there are day to day and seasonal variations in travel behavior that can only be captured by a multi week longitudinal survey Furthermore multi day travel survey data have been found to be more efficient and accurate estimators of trip generations Pendyala 23 provided a detailed literature review on day to day variability in travel behavior He noted there are two sources of day to day travel behavior variability people s needs and desires vary from day to day and behavior varies because of feedback from the transportation system In supporting his hypothesis he cited the research work of Hanson and Huff 9 11 us
66. een developed to capture the complete spectrum of traveler behavior The versions share most components differing only with respect to inertial sensors and GPS antenna selection The GPS ATD provides an intuitive user interface to capture trip activity information trip purpose travel mode etc with minimal user input a key design goal for the system Each survey participant interacts with their own personal GPS ATD and information is automatically coordinated between personal and vehicular GPS ATD units via ZigBee wireless The system captures and logs data from the GPS receiver allowing subsequent identification of corridors route lengths and regional and inter regional trips Because of the advanced and highly integrated design the GPS ATD can provide many enhancements beyond previous travel survey methods reduce the user burden by automating data collection and reducing data entry e provide activity time space relationships e minimize under reported trips e capture all modes of transportation and mode connectivity changes e provide vehicle position during GPS outages using inertial sensors vehicular GPS ATD e provide second by second detailed vehicle position speed acceleration and emissions information e provide wireless synchronization and allow survey duration up to 30 days The prototype was designed to be mass produced and deployable for future full scale household survey The resulting improved surveys will
67. em and Universal Serial Bus USB The I C bus connected to Analog Devices A D converter AD7994 battery monitor temperature sensor TCN75A and Maxim IC audio DAC control interface MAX9850 The serial UARTs are linked to the Globalsat ET 301 SiRF III GPS module the ZigBee CPU controller and the debug console The custom digital control lines allow the power management software to enable and disable power to LCD display LCD backlight GPS module audio devices MEMS inertial sensors and ZigBee wireless The two most significant libraries on the system are uClibc and Qtopia Core 4 uClibc is a C library that has been optimized for embedded systems and was chosen for its small 63 Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology memory footprint stability and large user base and hence better support community Trolltech s Qtopia Core is a heavily used cross platform application framework that 1s well suited to embedded Linux devices We developed Qtopia Core 4 patches to support our custom GPS ATD LCD display driver The data is stored in files on a dedicated YAFFS2 Yet Another Flash File System version 2 file system specifically designed for NAND Flash on the GPS ATD 256 MB NAND Flash The data files are in a custom log format that 1s interpreted by post processing tools after they are downloaded from the device T
68. er However this negative effect can be somewhat offset by the fact that the display 1s powered down n the portable version to conserve power when not in use At the bottom of Table 9 we see an importance table which is a weighting for the various system constraints The above constraint matrix 1s multiplied by the weighting vector resulting in the total weighted sum on the right of the table A more positive number represents a more efficient feature and a more negative number represents a less efficient feature The highlighted weighted sums represent features which are most highly recommended in Table 9 4 Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology Display Size Backlit 3 Graphics Menu Content Interface Method Onboard Flash Removable Flash Serviceman Download Flash Card Pickup Flash Card Mail Remote Batch Transfer Real time Transfer Unit to Unit Transfer GPS OBD II Accelerometer Gyro Temperature Battery Size Battery Type Rechargabilit Worse Same Better Importance 1 5 User Data Battery Survey Table 9 Feature cost benefit tradeoff analysis 42 Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology CHAPTER 4 COMPONENT TESTING AND EVALUATION GPS Sens
69. er consumption mode Thus the long start time may be eliminated Furthermore keeping the receiver on may eliminate the cold start time In addition the reacquisition time the time to reacquire the satellite signal lock when the signal was temporarily blocked varies from 1 to 3 seconds for different manufacturers Moreover GPS receivers perform differently in GPS challenged areas like urban canyons or heavily wooded areas Their size and power consumption varies as well These factors were closely examined in the project s GPS receiver testing and evaluation phase discussed 1n Chapter 4 uii Fm zd hi i b E a fe Figure 3 Example commercial GPS receivers Some GPS receivers can track weaker GPS signals better than other models A newly developed class of GPS receiver the High Sensitivity GPS HSGPS can operate in urban canyons with weak GPS signals supporting traveler behavior data collection in areas previously thought ill suited for GPS 18 26 Experiments conducted by the PLAN Position Location and Navigation Group of the University of Calgary show that a high sensitivity GPS receiver achieved 100 positional solution availability while a traditional high performance dual frequency survey type GPS receiver could only provide 30 availability in the same downtown Calgary urban canyon 18 However by their very nature HSGPS errors are typically larger 100 200 m in hostile GPS signal environments 18
70. erational time gt 3days time 3 days Ares metae interface Upgradeanie mare U firmware Besy instalation Niny Bi installation Suitable for vehicular Sutable for vehicular walking or Biking use __ or biking use Little or no Eie or ne capi Compactforsecurity for security LCD a CEN display 160x240 resolution Display Backlit o Automatic contrast control High Sensitivity Integrated GPS Easy mount GPS antenna Dead reckoning for GPS startup and low signal availability Gyro Acce User position for GPS startup User position for GPS low signal availability Vehicle Interface OBD II vehicle telemetry Wireless Unit to unit communication The travel diary contains all of the necessary sensors and interfaces to reliably collect the needed information with low user burden over the specified survey period Based on previous research the minimum survey period should be approximately four weeks in length This allows capturing the various patterns of the average traveler Intra week surveys tend to only capture quick and short term travel patterns and fail to fully sample long term long trip travel patterns Additionally to account for seasonal travel pattern variations this four week survey should be repeated quarterly These requirements suggest a compact data collection device which 1s easily deployable and installed by the end user 1 e the survey participant In general there will be two d
71. ersely affects the readability The LCD panel is directly connected to the 1MX21 LCD interface via an 18 pin 1 mm pitch ZIF socket The detailed electrical circuit design 1s provided in a supplement Circuit Board Design Because of the overall size constraints a custom 6 layer main circuit shown in Figures 16 to 20 was designed to connect all the electronic components Furthermore the circuit board has components on both sides totaling 130 components and 470 parts The bottom side of the circuit board shown in Figure 21 contains five power supplies battery charging and protection circuits and connectors to LCD and custom keypad The top side of the circuit board houses the CPU RAM NAND and GPS module Figure 17 All layers and layer 3 of the GPS ATD circuit board Figure 18 Layer 4 and layer 5 of the GPS ATD circuit board When capturing the design to schematics each component must be defined as a part for Mentor Graphics DxDesigner We have developed an extensive in house database containing all of our desired parts part specifications cost size power availability RoHS Restriction of Hazardous Substances status and inventory This database interfaces directly with the Library Manager of DxDesigner which uses the part attributes from the database and then associates the part to a specific DxDesigner symbol Although these schematic symbols can be created manually in DxDesigner our automated process using software d
72. es ZigBee wireless communications to the car computer On Board Diagnostics connector OBD II Following the design discussion complete system testing results and user feedback are discussed The report concludes with recommendations for future work related to the GPS ATD and its use in the 2010 California Statewide Household Travel Survey 111 Copyright 2011 AHMCT Research Center UC Davis Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology EXECUTIVE SUMMARY This report provides a basic background and brief summary of longitudinal travel surveys the use of the Global Positioning System GPS in previous surveys and new technological developments that can improve surveys by increasing GPS availability and reducing the cost of conducting a survey It s fundamentally important that surveys can be carried on for a long duration while maintaining the survey data accuracy and integrity and yet minimizing the burden on survey respondents Therefore a new method is needed for comprehensive highly automated and efficient data collection for individual travelers The survey data are crucial for modeling trip generation predicting the effects of transportation policy changes and supporting the decision making process at the Federal State county and city level In this project a new solution was developed to address known deficienci
73. es of previous approaches The mismatch between existing methods and the stated needs of travel surveyors drove the Global Positioning System Automated Travel Diary GPS ATD system specifications and developments Previously typical travel survey duration was one or two days however researchers have shown benefits 1f the duration 1s extended to beyond one or two weeks Therefore the GPS ATD was designed with storage to handle four weeks of data For prior attempts at applying GPS receivers for travel surveys long GPS startup time and signal blockage in urban canyons were major obstacles thus Micro Electro Mechanical Systems MEMS inertial sensors were used for dead reckoning to calculate position solutions when GPS s not available The report documents the well balanced GPS ATD system design which meets data storage and cost constraints while minimizing the survey respondents burden Readers are strongly encouraged to read the references cited herein along with a sampling of the papers cited in these references to gain a deeper understanding of longitudinal travel surveys and the benefit provided by the GPS ATD system This report provides an overview of travel surveys including literature review and background as well as the motivation for the research and development of the GPS ATD The system requirements and specifications for the device development are presented and discussed In addition the detailed architecture hardware sof
74. esearch Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology TABLE OF CONTENTS ADS ACE OOOO GOO AGORA Id eDEE lii EX COULIVE SUTIN GT RR y Table OF Contents acce ae vii EIS I Gda ian ii ix LOCO TV ADIOS T M xi DiSciauner DNCLOSUTE poi ii dA ea xiii List of Acronyms and Abbreviations c eeee esses eese eese eee eene eee eere eee eee eese eene Xv Acknowledsmenis usd ait oto tiii uo OOO e a bu xvii Chapter 1 Introduction and Background aaa aaa aaa aaa eee eee eee eee eerte 19 Longitudinal Traveler Survey and Demand Forecast Modeling 19 Previous Travel Survey S aa Eo eo east 20 Chapter 2 Recent Emergence of Supporting Technologies 27 Current Global Positioning System GPS Status eee e eere eere eene 27 Free Nationwide Differential GPS DGPS Services 2200022000000000000000000000000000000000 28 GPS Vulnerability a asseeve O Wasi UR sine Nee 30 GES SENSOIS ar GA CA OO NWA 30 Low Cost Inertial Sensors for Dead Reckoning e eee rece eee ee eee enun 32 Other New Technologies to Improve Travel SurveyS 000000000000000000000000000000000000000000 33 Vehicle On Board Diagnostic OBD Interface eeeeeaa a
75. eveloped in house improved productivity and reduced human errors This software uses Microsoft Excel as the base application due to its excellent ability to manage information in a row column format and implements custom operations in Visual Basic for Applications code First tabular or grid data from the component PDF or HTML datasheet is copied and pasted into a blank Excel spreadsheet 56 Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology After that the user assigns symbolic pin locations and arrangements to the various pin names and numbers The pin list is then consolidated Finally the symbol is written to file and imported to the Mentor Graphics Library Manager The Library Manager associates this symbol and the part attributes and provides the part data to DxDesigner for placement This process and workflow reduces human error in data entry After the entire system is captured to schematic attributes such as trace timing crosstalk trace width and minimum spacing these parameters are then exported to the layout tool Mentor Graphics Expedition Expedition uses these parameters to control characteristics of the final PCB such as signal timing and noise In Expedition the board outline is drawn and parts can be initially placed on the top and bottom layers For the GPS ATD primarily all functional IC s were placed on the
76. f Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology Acronym NDGPS NiMH NMEA M Operating System OSS Open Source Software Portable Document Format RA Random Access Memory Radio Frequency PLAN Position Location and Navigation MF MP PO BD OS CB DA DF OR M RF I SA BC M MC TSI CD RoHS Restriction of Hazardous Substances RTOS Real Time Operating System SDRA T TSOP TUCF UART U UI USDOT USNO VDOP O P P P P RF S Radio Frequency Interference PAPI Paper and Pencil Interview Printed Circuit Board Personal Digital Assistant Pacific Ocean Region WAAS YAFFS2 U U V W SB TC MT Vehicle Miles Traveled GS ZIF XVI Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology ACKNOWLEDGMENTS The authors thank the California State Department of Transportation for their support n particular the guidance and review provided by Dr Ayalew Adamu Chief of the Statewide Analysis Branch of the Office of Travel Forecasting and Analysis in the Division of Transportation System Information TSI of the California Department of Transportation Caltrans and the staff members of the Statewide Travel Analysis Branch and the Statewide Modeling Branch Staffs withn TSI He and his research staff created the idea and wrote specifications for the
77. he GPS ATD to impact Impact may result in a damaged display broken glass or leaking fluid possibly resulting in serious injury e Store and operate the GPS ATD out of reach of small children e Do not cover the GPS ATD with a cloth paper or cushion e Do not use the supplied AC adapter with any device other than GPS ATD e Use only the supplied AC adapter or Auto charger to charge the GPS ATD e Insert the AC adapter power plug firmly into the power outlet e When removing the power plug from the power outlet do not pull directly on the cable Always hold the plug to remove it e Do not connect or disconnect the power plug with a wet hand e Connect the power plug of the AC adapter only to a 120 Volt AC source Connecting the power plug of the AC adapter to a power outlet power source other than 120 VAC may result in fire or electric shock possibly resulting in serious injury e Do not attempt to disassemble modify or repair AC adapter Any modification may result in fire electronic shock or burn and serious injury e Do not cover the AC adapter with cloth paper or cushion or place it near a heater or on carpet when the adapter 1s conducting current e Do not subject the AC adapter power cable to any of the following o Scratching extending or otherwise modifying IV Copyright 2011 AHMCT Research Center UC Davis GPS Automated Travel Diary User Guide o Heating o Pulling placing below a heavy object or pinching
78. he GPS antenna on the roof 48 Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology Table 10 Number of available satellite summary statistics No Blockage Blockage Blockage Blockage Blockage lion dm PME City Mean Dev Mean Dev ean e Mean Dev Mean Dev ECT jus os am oe PPS CA 0 61 0 0 0 8 12 8 16 10 54 San Sacramento CA 5 0 05 N N A N A N A N A N A N A N A 9 48 71 0 06 9 28 0 05 Available GPS Satellites at Los Angles CA under various Signal Blockage Conditions e No Blockage Southern Blockage Northern Blockage e Eastern Blockage e Western Blockage Freqency 5 min interval 2 Days Duration 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Number of Satellite Figure 14 Simulated effect of placing the GPS antenna on the dashboard vs on the roof No blockage line represents GPS antenna on the vehicle roof and the others represent GPS antenna on the vehicle dashboard traveling in various directions 49 Copyright 2011 AHMCT Research Center UC Davis Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology CHAPTER 5 HARDWARE DESIGN AND IMPLEMENTATION The system design shown in Figure 1
79. he primary function of the GPS ATD survey application 1s to collect and record data from the onboard sensors along with information obtained interactively from the user The interactive user interface behavior is governed by state machines each of which was designed by the Caltrans TSI group to collect the desired information for a particular mode of operation The behavior of the application and its menus can be switched among various modes each of which can be described by a text file and the device could support other data collection activities with appropriate application and interface development User Interface The GPS ATD user interface 1s shown in Figure 27 The LCD display s divided into three areas the GPS ATD status area located at the top the travel survey question area located 1n the middle within a rectangle graphic and the survey answer menu selection area located on the bottom of the display The user selected item 1s highlighted User survey respondent inputs are provided though four application specific keys located to the right of the LCD display The user can move the desired selection item by pressing the Up A or Down V key The user can cancel the selection and go back to the previous menu by pressing the Back Cancel x key and can pick the selected menu item by pressing the OK Select v key In a typical trip there are two sets of questions to be answered The first set should be answered right before the
80. iary units one for the vehicle and one portable unit for each user These two units share common features and functionality Both vehicular and wearable personal versions are based on a shared modular system architecture Furthermore both vehicular and personal GPS ATD units can operate in passive interactive or hybrid mode Moreover they are simple to use robust compact low power light weight simple to install esthetically pleasing rugged and low cost for easy 36 Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology implementation in a wide array of vehicles or travel modes for the portable units The units are entirely self contained with all of the sensors integrated into a single package The sensor outputs positional and temporal data are collected automatically by an onboard embedded processor and stored in solid state memory Human machine interfaces HMI that are overly complicated or tedious are viewed negatively and can impact the data collection and the survey results The HMI can address biases of potential language barriers literacy or technology illiteracy Use of customizable icons and menus has been successful in the past Previous electronic travel diary HMI approaches were used as a reference and baseline guide The user interface 1s based on a Liquid Crystal Display LCD and application specific bu
81. ing the 1971 Uppsala Sweden household survey data 35 days long 149 individuals using self administered travel diaries Pas and Koppelman s 14 19 22 analysis of both 1973 Reading England and 1989 Seattle Washington travel survey data and Kitamura and Van der Hoorn s 13 examination of Dutch National Mobility panel data Previous research suggests that there is substantial day to day variability in travel behavior Furthermore Richardson suggested that the number of sample households may be reduced if the study duration increases 25 In order to accurately capture the full spectrum of travel behavior it 1s 22 Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology fundamentally important that surveys can be carried on for a long duration while maintaining the survey data accuracy and minimizing the burden on the respondents Table 4 Summary of previous GPS aided travel survey diary hardware Researcher Survey Description Year Lexington KY Fall 1996 Sony MagicLink PIC 2000 with interface software that controlled the recording of GPS data and allowed respondents to enter trip information 2 MB storage Transport ETD with handheld data logging devices equipped Research Centre with a combined GPS DGPS receiver and battery AVV pack Netherlands 1997 1998 Passive in vehicle GPS system Quebec city Dec 199
82. ion and post processing phases Recommended GPS Aided Electronic Travel Diaries Systems The current project focuses on development of the data collection units 1 e on the Phase I portion of the architecture Vehicular and personal GPS Automated Travel Diary GPS ATD systems have been developed to address the need for comprehensive travel behavior study data collection The devices support interactive passive and hybrid operating modes hybrid implies any of a variety of modes between interactive and passive Ideally the system would capture all pertinent data over the entire survey period without zero burden on the user in question clearly this is never the case and we seek to approach a reasonable set of criteria These features are summarized below in Table 5 and are based on user responses in exit surveys and analysis conducted in prior research referenced in this report The objective was to provide internal and external 35 Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology decision makers and stakeholders with current accurate reliable and spatially dense traveler behavior data at a significantly reduced cost Table 5 ati features 4 week data Anoek data captu OO Nemea lesh data Flash ee 5 user Intuitive user interface Reduced user burden U user burden Travel aa 12 0 SOOO 712 oz Diary Low EZ Low power op
83. ip package These were widely available through several distributors Choosing the NAND Flash was much more complicated The CPU can operate all memory interfaces at 1 8 V or 3 3 V The only available 256 MB NAND Flash components used a 3 3 V interface not the desired 1 8 V interface The CPU memory bus can be configured to operate at 3 3 V to work with more power consuming 3 3 V SDRAM and 3 3 V Flash Alternatively the CPU can be configured to interface with 1 8 V SDRAM and 3 3 V NAND Flash through a 1 8 V to 3 3 V transceiver The latter design increases part count by about 30 and raises cost and complexity but has lower power consumption than the first alternative and was the option selected for the GPS ATD A Micron 3 3 V 256 MB NAND Flash memory with 48 pin TSOP Thin Small Outline Package Type 1 package was selected The last major dependency of the CPU is the power supply rails and the sequencing of these rails during system power up and down The CPU has a specific requirement of turning on higher voltages before lower voltages so that reverse biases are not exceeded during startup and conversely during power down Therefore the power supply sequencing circuitry must meet the CPU power sequencing requirements Furthermore all power supplies were designed as high efficiency step down switching regulators to maximize battery life These power switching supplies along with other digital switching circuitry add noise to the system Mitiga
84. ity Hybrid Other Don t Know Owned or Leased Owned by a household member Owned by a person not in your household Leased by a member of your household Rented by a member of your household Don t Know un gt eii D gt A D un IE K 2 c D m t c D D 8 Strikethrough are confidential fields Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology HOUSEHOLD INFORMATION Table 1 continued Pre Entered Data 5 To be close to a family member or friend receiving medical care in a medical facility 0 0000 0 0 0 00000 i 6 Looking for permanent housing _ 1 0 1 7 Other Annual Household Income Wages salary commissions bonuses or tips from all jobs Report amount before deductions for taxes bonds dues or other items dA lt 10 000 00 0 00 0 0000 LL PNE 15 000 824 999 gt Se 25 000 34 999 eee 4 _ 35 000 49 999 a E 5 1 50 000 874 999 OL E 6 al 75 000 99 999 OOOO MD 100 000 149 999 a E 8 150 000 199 999 OL 9 200000 0 0 000 00 00000 0 LLL nen USUS MG NEN 1 _Language s Spoken in the Home up to 3 languages Io o English MN 2 Spanish o SE Tagalog 0000000000000 LLL AE Chinese eee E 5 Japanese 0000000000 Li 6 i Vietnamese a 9 Other 81 Strikethrough are confidential fields Copyright 2011 AHMC
85. ld Travel Survey Final Report California Department of Transportation 2002 J Collin O Mezentsev and G Lachapelle Indoor Positioning System Using Accelerometry and High Accuracy Heading Sensors in Institute of Navigation GPS Conference Portland OR September 9 12 2003 P David OBD II Diagnostic Secrets Revealed Kotzig Publishing Boca Raton FL 2002 R de Jong and W Mensonides Wearable GPS Devices as a Data Collection Method for Travel Research Institute of Transport Studies University of Sydney Rept ITS WP 03 02 Sydney Australia 2003 G Draijer N Kalfs and J Perdok GPS as a Data Collection Method for Travel Research in 79th Annual Meeting of the Transportation Research Board Washington D C January 2000 R Guensler and J Wolf Development of a Handheld Electronic Travel Diary for Monitoring Individual Tripmaking Behavior in 78th Annual Meeting of the Transportation Research Board Washington D C January 1999 S Hanson and J O Huff Assessing Day to Day Variability in Complex Travel Patterns Transportation Research Record 891 pp 18 24 1982 s Hanson and J O Huff Classification Issues m the Analysis of Complex Travel Behavior Transportation 13 pp 271 293 1986 s Hanson and J O Huff Systematic Variability in Repetitious Travel Transportation 15 pp 111 135 1988 B Hofmann Wellenhof H Lichtenegger and J Collins Global Positioning S
86. ment worker Self employed workers in own not incorporated business Unpaid family workers 85 Strikethrough are confidential fields Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology VEHICLE Table 3 User Input Vehicle ID Number Ordinal Variable Vehicle ID Number from Table 1 Don t Know 86 Strikethrough are confidential fields Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology MODE OF TRANSPORTATION Table 4 User Input Code Auto Truck Van p Driver Passenger i in car truck van NENNEN Transit Local bus Express bus Commuter Bus Light rail Street car Trolley Cable car Coaster M Ferry Metro Blue Line Metro Green Line Metro Red Line BART Metro Link Heavy Rail CALTRAIN Amtrak Dial A Ride Para transit School Bus Chartered bus for school activities _ Other Modes Walk Bicycle Motorcycle moped Taxi shuttle bus limousine Greyhound Trailways Intercity bus Airplane commercial Airplane private Other Don t Know Refused Will you use more than one mode of transportation for this trip Yes 87 Strikethrough are confidential fields Copyright 2011 AHMCT Research Center UC Davi
87. n Chipcon transceiver resulting in a two chip design with a Silicon Labs CPU interfacing to a Chipcon transceiver A minimal radio frequency RF circuit and dipole antenna was designed following Chipcon application notes Consequently PCB block area usage power consumption and cost doubled for the ZigBee block design Table 11 GPS ATD system hardware Vehicle OBD II via ZigBee PC Interface USB 2 0 2 G max with 5 mG resolution 75 deg sec max Microtips 160x240 grayscale with EL backlight 4 application specific buttons 1800 mA h Li Ion polymer battery Power 4 Switching supplies o 4 Switching supplies Weight 4 5 oz Vehicular GPS ATD 5 oz Personal GPS ATD 2 62 x4 4 x0 83 Remaining major components are summarized here and the main hardware components selected are listed in Table 11 A USB 2 0 data interface was implemented to support high speed data download An 1800 mAh Li ion Lithium ion polymer rechargeable battery was selected because of its high power density compared to other rechargeable batteries as well as form factor allowing a better fit inside a COTS plastic case A grayscale 160x240 resolution LCD was selected rather than color due to better readability in all lighting conditions particularly under bright sunlight A four button membrane custom keypad was designed by the AHMCT team and fabricated by a custom keypad maker The system can be charged by a power supply via a mini USB connector commonly fo
88. n I I BIER Goa Figure 2 GPS A D Side View e T Figure 3 Charging GPS A TD uice trot vereor buta v e eir w asics ben aaa Te MEER a IX Copyright 2011 AHMCT Research Center UC Davis Copyright 2011 AHMCT Research Center UC Davis GPS Automated Travel Diary User Guide LIST OF TABLES Table 1 Features Synthesized with the Following Hardware Table 2 Comparison of Vehicular and Personal Versions of GPS ATD XI Copyright 2011 AHMCT Research Center UC Davis Copyright 2011 AHMCT Research Center UC Davis GPS Automated Travel Diary User Guide DISCLAIMER DISCLOSURE The research reported herein was performed as part of the Advanced H ghway Maintenance and Construction Technology AHMCT Research Center within the Department of Mechanical and Aeronautical Engineering at the University of California Davis and the Division of Research and Innovation at the California Department of Transportation It is evolutionary and voluntary It is a cooperative venture of local State and Federal governments and universities The contents of this report reflect the views of the authors who are responsible for the facts and the accuracy of the data presented herein The contents do not necessarily reflect the official views or policies of the State of California the Federal Highway Administration or the University of California This report does not constitute a s
89. nal Travel Diary Systems using GPS amp New Technology near the transceiver which was placed as close as possible to the center tapped folded dipole antenna The power was distributed to all components on the PCB through eight different power nets Three power planes were implemented on the power layer two on the vertical s gnal layer and three more on the bottom layer The ground plane was uniform and limited to the ground layer Although we had s gnificant prior in house experience with the manufacturing of fine pitch components onto PCB s th s project turned out to be vastly more difficult than any of our prior efforts The trace space was fine but not anything that most PCB fabricators cannot handle however the via in pad was something relatively new to most of them This raises an interesting application oriented question the only way to avoid the via in pad requirement for fine pitch devices s to drastically increase the layer count The primary PCB cost design decision boils down to which is a more economical alternative a via in pad low layer count PCB or a no via in pad high layer count PCB We opted for the former alternative as it is simultaneously more advanced and more cost effective within the constraints of our prototype environment dd E d ia u i Frid LMB EAN maa TI Figure 19 GPS ATD circuit board 58 Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal
90. ncy Built in charger The data budget shown in Table 8 provides the various data and related sampling rates The duty cycle represents the percent time that the sensors in question are sampled These are realistic sampling rates which assume a maximum of 8 hours of usage per day resulting in approximately 30 days of storage utilizing 128 MB of internal Flash It is important to note that the user and or trip information 1s taken only once while the bulk of the data gathered is GPS based To ensure high positional data confidence the gyroscope and accelerometer are adaptively sampled 1 e at varying rate depending on conditions to complement the GPS data The vehicle data will also be sampled adaptively It is important to always keep in mind that one of the major goals of this work is to reduce the user burden and maintain the data quality One way this can be achieved is to drastically reduce the amount and difficulty of end user data input which can be achieved by deriving as much information as possible in post processing This goal was always in the forefront when analyzing the various systems suitable for this development 39 Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology Table 8 Data elements and update rates adjusted time 2 1 2 1 2 laitue 4 1 4 1 longitude Jatte 4 1
91. nd military user requirements GPS receivers collect signals from the satellites in view a k a line of sight They provide the user s position velocity and time and some receivers give additional data such as distance and bearing to selected waypoints or digital charts after further processing of the positional and time solutions Without going into full detail each satellite transmits an accurate position and time signal The user s receiver measures the time delay for the signal to reach the receiver which provides a direct measure of the apparent range called a pseudorange to the satellite Measurements collected simultaneously from a minimum four satellites are processed to solve for the three dimensions of position latitude longitude and altitude and precise time Position measurements are in the World Geodetic System WGS 84 geodetic reference system and time is with respect to a worldwide common U S Naval Observatory USNO time reference For more information see Hoffmann Wellenhof et al 12 Until recently Selective Availability SA was used to protect the security interests of the United States and its allies by globally denying the full accuracy of the civil system to potential adversaries SA was turned off at midnight on May 1 2000 and it is not the intent of the U S to use SA ever again Currently with removal of SA accurate position 25 m time and speed can be obtained throughout the country using small
92. nd vehicle identification 5 These data may be useful 1n estimating vehicle emissions In addition vehicle speed could be input to a Kalman filter to improve dead reckoning and provide an estimate of vehicle miles traveled VMT when the GPS signal is not available Wireless Technology Developments Coarse data may be transmitted automatically in real time via CDMA Code Division Multiple Access or GSM Global System for Mobile communications and high resolution sampled data may be stored for subsequent automatic transfer without any user input via a high speed wireless network Bluetooth or WiFi 802 11 and high speed Internet connection Digital Subscriber Line DSL or cable modem once the vehicle is parked at the end of the trip Data may also be stored in internal solid state Flash memory for later retrieval 1f a data link 1s not available Real time vehicle data transfer allows the vehicle to act as a probe for traffic congestion 2 17 These data would be valuable to a Transportation Management Center although this was not addressed in the current research These technological advancements have increased the system s robustness and availability and reduce survey costs and needed user interaction The result is a physically small low cost embedded system which is easily installed and which creates minimum impact or burden on the respondent while providing the maximum accurate and complete data collection 33 Copyright 2011 AH
93. nductor packages The small component package size and large part count increased the assembly time approximately 4 to 6 hours per side Most significantly the RoHS soldering process caused low yield and decreased reliability RoHS soldering processes are much less robust compared to traditional lead based soldering processes New solder paste must be used and this paste is very sensitive to temperature variation and has a much shorter shelf life All semiconductor parts are subjected to higher solder temperature profile Months were spent to refine and improve the RoHS soldering process to an acceptable yield and reliability since all of the parts were RoHS compliant previous lead based solder paste and reflow procedures could not be employed The first test boards were soldered using these procedures and the resulting assembled boards were very unreliable with many marginal or bad solder joints Through six months of experimentation and trial and error a new lead free soldering process was refined and improved to provide acceptable yield and reliability We determined that it 1s critical to use very freshly made lead free paste and follow a strict optimal reflow profile to avoid BGA pin disconnects Through repeated tests using a thermocouple on the circuit board to verify the reflow temperature profile the oven temperature profile was carefully adjusted Lead free solder paste is much more sensitive to temperature variation on the circuit boar
94. ng these technologies a system can collect positional and temporal data automatically and accurately with high availability Furthermore in some cases acceleration and speed profiles and other driving characteristics could be used to determine driver identity Figure 4 Analog Devices MEMS gyro and accelerometer chips 32 Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology Other New Technologies to Improve Travel Surveys Vehicle On Board Diagnostic OBD Interface All 1996 and later vehicles are equipped with a standard On Board Diagnostic OBD version II data bus including an OBD II Diagnostic Link Connector which enables a diagnostic scan tool to communicate with OBD II compliant control units via protocol ISO9141 2 JI850 PWM or J1850 VPW depending on the make of the vehicle According to the 2000 2001 California Statewide Travel Survey 62 7 of the vehicles are less than 10 years old implying that approximately 62 7 of vehicle currently on the road have an OBD II interface This percentage will increase over time and can be expected to be higher when the next Statewide travel survey is conducted OBD II provides real time vehicle operating parameters such as engine coolant temperature calculated load fuel trim fuel pressure engine RPM vehicle speed intake air temperature throttle position oxygen sensor output a
95. nments through the Use of Extended Dwell Times in nstitute of Navigation GPS GNSS Conference Salt Lake City UT September 9 12 2001 P R Stopher P Bullock and F Horst Exploring the Use of Passive GPS Devices to Measure Travel Institute of Transport Studies University of Sydney Rept ITS WP 02 06 Sydney Australia 2002 P R Stopher P Bullock and Q Jiang GPS GIS and Personal Travel Surveys An Exercise in Visualisation in Australian Transport Research Forum Canberra October 2 4 2002 P R Stopher and C G Wilmot Some New Approaches to Designing Household Travel Surveys Time Use Diaries and GPS in 79th Annual Meeting of the Transportation Research Board Washington D C January 2000 R Tourangeau M Zimowski and R Ghadialy An Introduction to Panel surveys in Transportation Studies Federal Highway Administration 1997 J Wolf Using GPS Data Loggers to Replace Travel Diaries in the Collection of Travel Data Ph D Dept of Civil Engineering Georgia Institute of Technology 2000 J Wolf R Guensler and W Bachman Elimination of the Travel Diary An Experiment to Derive Trip Purpose from GPS Travel Data 1n 80th Annual Meeting of the Transportation Research Board Washington D C January 2001 J Wolf R Guensler L Frank and J Ogle The Use of Electronic Travel Diaries and Vehicle Instrumentation Packages in the Year 2000 Atlanta Regional Household Travel Survey Test Resul
96. nsors are adaptively sampled as required with the resultant data also stored in binary format for maximum memory utilization The wireless interface 1s based on the familiar ZigBee technology and is used for unit to unit communication The user interface 1s based primarily on a 160x240 resolution LCD graphic display with backlighting and automatic contrast control to ease user burden The main input 1s by application specific custom buttons In the case of the portable device the system will be powered by Lithium ion battery and will include a built in charger The system will be connected to a power supply similar to cell phones for recharging Power calculations and lab tests suggest that the portable system should be able to run for three days during business hours 1 e 38 Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology approximately 8 hours per day Longer operational periods could be achieved by powering down in certain scenarios e g when the user device is at rest or is riding In a car with a vehicle system already gathering data Table 7 GPS ATD system hardware Interface ZigBee GPS DGPS Vehicle Interface OBD II 2 G max with 5 mG resolution 75 deg sec max 160x240 backlit automatic contrast User Interface control Application specific buttons Lithium ion battery Power Switching supply 95 efficie
97. o a better understanding of the factors that influence and direct personal travel behavior These data are critical in e developing travel demand models and forecasting future demand e predicting the number of trips generated by households as a function of demographics socioeconomics and location relative to employment and commercial centers 31 e estimating travel mode choice and traffic volumes on various roads e measuring and understanding trends in population behavior 19 Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology e assessing the impact of changes in transportation policy or the transportation system 7 23 30 e predicting emissions from motor vehicles and input for air quality analys s 31 e and calibrating regional models Previous Travel Surveys Household level travel surveys collect three categories of data household information household member personal information and travel activity information for a particular day or range of days see Table I and Table 2 Travel diaries are the standard method used to capture participating household travel activity information Travel diaries have progressed over the last few decades due to improved understanding of trip generation as shown in Table 3 The most recent trend in travel surveys is the use of the place based survey instead of a trip
98. omponent selection process because of interdependences component selection affects schematic detail and conversely Once the system level functional design is defined the system level blocks can then be synthesized into a component level design Since the CPU connects to most components the CPU system block design is initiated first This block contains a 266 MHz Freescale 1 MX21 32 bit ARM processor in a 256 pin Fine Ball Grid Array FBGA package configured to operate at 1 5 V with memory buses running at 1 8 V and all other interfaces running at 3 3 V This design provided the lowest operational power requirements for this system block Further reductions in the system power consumption can be attained by further throttling the software configurable operating frequency from the initial clock frequency of 133 MHz we opted to run the chip at half speed for power 24 Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology savings The remaining CPU dependencies are clock crystals SDRAM NAND Flash storage and necessary power rails and sequencing requirements Clock crystals are available from several manufacturers and suppliers in a variety of sizes generally at low cost Based on initial software run time memory requirement estimate 32 MB of RAM was selected using two 1 8 V Micron SDRAM 128 Mbit x 16 bit wide bus in a 54 ball FBGA ch
99. on the manufacturer s power supply design and simulation software The noise impact on the GPS signal LNA circuitry was higher than anticipated which degraded GPS receiver performance significantly Although the GPS ATD units do vary slightly with respect to noise performance the major contribution to noise s believed to be a function of design choices rather than manufacturing and component tolerance variation Figure 28 Personal GPS ATD mni i iH W m Figure 29 Personal GPS ATD with optional patch antenna A typical fully charged battery provides twelve hours of continuous GPS ATD operation significantly exceeding the initial design requirement of eight hours Continuous run time may be further extended by adding power management software The user can recharge the battery at any time by plugging the AC adapter into the GPS ATD mini USB port on the side of the unit next to the GPS antenna Charging takes approximately four hours for a completely discharged internal battery The GPS ATD battery management circuitry prevents over charging or discharging of the internal Lithium ion battery Figure 30 shows a typical battery voltage charging curve The battery charging circuit charges a fully discharged Li ion battery from 3 5 V to a fully charge voltage of 4 15V At 4 15V the battery charging circuit automatically disconnects the battery from the power source and hence prevents any over charging of the Li ion battery Figure 31
100. or Test Results The GPS receiver is the most critical sensor on the GPS ATD A newly developed class of GPS receiver the High Sensitivity GPS HSGPS can track weaker GPS signals better than previous GPS receivers and provide positional solution n challenging GPS environments such as urban canyons some indoor areas and parking structures It can support traveler behavior data collection in areas previously thought ill suited for GPS 18 26 such as inside a bus or tra n Experiments conducted by the PLAN Position Location and Navigation Group of the University of Calgary show that a high sensitivity GPS receiver achieved 100 positional solution availability while a traditional high performance dual frequency survey type GPS receiver could only provide 30 availability in the same downtown Calgary urban canyon 18 However by their very nature HSGPS errors are typically larger 100 200m in hostile GPS signal environments 18 Nevertheless these large positional errors can be eliminated by map matching and or use of inertial sensors such as a rate gyro 4 15 24 These recent developments will greatly improve Longitudinal Travel Behavior surveys Intensive testing on different GPS receivers was performed to determine the model best suited for the traveler behavior survey data collection application Commercially available GPS receivers and components were evaluated on their e size power consumption and weight e cold start acq
101. oreover most receivers can also communicate solution data using proprietary binary communication protocols at a higher baud rate allowing more data or more frequent updates Most GPS users would still not know where they are given their position in latitude longitude and altitude with this raw data most users can at best tell whether they are in the northern or southern hemisphere A digital map or a Geographic Information System GIS database 1s required to determine the user s state city and street location Some receivers have incorporated mapping functions and GIS database They have more memory Flash storage and powerful processors However most handheld units can only store a coarse state map or a detailed city map Digital maps and GIS databases vary in size depending on the number of detailed entries For example Microsoft MapPoint software has a 1 Gigabyte GB GIS database map for all of North America 30 Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology Each GPS receiver has its own power on sequence where it downloads almanac data such as GPS satellite orbital information before establishing a position and time fix This start up time is referred as cold start time typically between 45 sec to 5 min Some receivers have a sleep mode in which the receiver keeps all the almanac data in memory using a low pow
102. ounty or region and Traffic Analysis Zone TAZ Vehicle type Vehicle occupancy number of people n vehicle Driver or passenger Trip cost out of pocket cost for instance parking and toll paid Delay factor e g congestion acc dent and railroad crossing Types of fuel 3 System architecture for both vehicular and personal Universal Longitudinal Travel Diary 4 Component technology test results 5 Ten vehicular UnLTD units 6 Ten personal UnLTD 7 Final prototype test results and performance limitations 8 Develop GPS User Guideline for both vehicular and personal GPS device 9 Provide forty 40 copies of final reports in CD format and ten 10 printed copies including analysis and documentation CopyPssbleih StNEGeRtstaR8 OSiterQHMBatiag Traveler Behavior 2
103. pose commute to work business and recreation and various trip modes 1 e Local bus Express bus Light rail Street car Trolley San Francisco San Diego San Jose Sacramento Metro Blue Line Metro Green Line Metro Red Line BART Heavy Rail Metrolink CALTRAIN Amtrak School Bus Passenger in car truck van Motorcycle moped Driver Taxi shuttle bus limousine Greyhound intercity bus Airplane commercial Airplane private e Prepare summary report of findings Evaluate various systems and recommend best alternatives for items a through d 2 Develop data collection and system requirements a Trip information includes 1 Mode of travel 2 Trip activity CopyPssbleih SEHT HRE OSiterQHMBatiag Traveler Behavior l a xpo Sour SE ZN R 10 11 12 13 14 15 16 Is 18 19 20 21 Trip purpose Home Other Other Other Work Other Home Work Home Shop Business Recreational Time of trip start and end Route Identification Tr p duration Date of travel and total tr ps made during survey period Trip distance Is th s a linked tr p e g change travel mode drop off or pick up passenger For linked tr p definition see page 296 of the 2000 2001 California Statewide Travel Survey Public transit trip duration Vehicle Mile Travel VMT Speed Origin and destination locations of each trip Regional vs interregional trips Record crossing jurisdictional boundaries e g city c
104. provide decision makers with current accurate and reliable traveler behavior data Recommendation for Future Research The current GPS ATD is a first generation proof of concept prototype and several improvements are required before mass production and final deployment Future improvements would affect the cost size and technical performance of the overall system The first subsystem to be improved would be the NAND Flash Currently the 256 MB Flash is implemented as a 3 3 Volt TSOP Flash necessitating a level translator 71 Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology to 1 8 Volt signaling and glue logic Future revisions should use recently available NAND Flash with 1 8 V and a new smaller BGA package consequently the size requirements in the PCB area would reduce and the total part count and associated assembly cost would be reduced by eliminating the level translator and glue logic The new Flash chip would likely be cheaper than the older one due to obsolescence Furthermore Freescale has recently released a lower cost 1M X27 CPU which is exactly like the 1 MX21 CPU except for support for some peripherals that are not used in GPS ATD Although they are pin compatible some board design and software changes may be required to use the new 1 M X27 CPU The personal unit s GPS performance is sub optimal The
105. pset tend to perform very similarly Since GPS receiver modules are usually more difficult to obtain COTS commercial off the shelf GPS 43 Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology receivers were used in the initial testing The main objective of the initial test was to determine which GPS chipset performance best under various conditions The major embedded GPS chipset makers are as of 2007 Garmin SiRF Sony NemeriX Tyco Trimble and Atmel u blox Note that throughout this report trademarks and copyrights are property of their respective owners and are omitted for conciseness To reduce testing time the GPS chipset selection process was conducted on an elimination basis with the goal to find the most suitable GPS chipset for GPS ATD use rather than fully characterize the performance of each GPS chipset under any conceivable conditions GPS chipset performances were directly compared If a GPS chipset performed poorly vs the other GPS chipsets in one test it was immediately dropped from further testing Since the handheld personal GPS ATD with be used in particularly challenging GPS environments availability of the solution is far more important than accuracy The final GPS test candidates were Garmin 18 GPS Holux GR212 SiRF II Xtrac iTrek BT NemeriX 1 generation chipset Sony GXV5005 GPS module San Jo
106. r Personal Ver rip Distance by GPS ost of Trip Fees Parking Toll etc OFA SSS zi D gt e amp Un ko C I r 6 g lt eo y un witching Mode of Travel umber of Passengers BD II Interface Data Acceleration Yaw Rate emperature I J a lt O 7 a O oO O mp ER zaje zZ gt E 2 18 AHE C 27 e O C gt oO 22 Copyright 2011 AHMCT Research Center UC Davis GPS Automated Travel Diary User Guide APPENDIX A ATD MENUS FLOWCHART 23 Copyright 2011 AHMCT Research Center UC Davis Copyright 2011 AHMCT Research Center UC Davis GPS Automated Travel Diary User Guide GPS ATD Active Mode Menu Flowchart If mode selection is Auto truck van Motorcycle or Other Please select a trip activity sub category Home Please select a trip Number of passengers including yourself Yes less han 1 00 Yes 1 00 1 99 Yes 2 00 2 99 Yes 3 00 3 99 Yes 4 00 4 99 Yes more than 5 00 Un boarding airplane rail intercity Pick up Drop off 1 activity sub category l 2 Working at home Travel Did you pay a toll on 3 Shopping at home your trip 4 SE at home d Get on vehicle Wait for a ride Is there a change of 5 Leave Park a vehicle No Boarding airplane rail intercit drivers 6 bus g p y Number of person s Yes prepaid 7 8 a 10
107. ravel umber of Passengers BD II Interface Data Acceleration Yaw Rate emperature I J a Z O Un 2 O o gt O O h m EE e 7 3 O O A 3 His Em o O E By automating the collection of accurate and objective data GPS ATD units may eliminate traditional paper diaries altogether Furthermore previous research has shown that given appropriate GIS information trip purpose travel mode travel duration travel mode switch speed acceleration deceleration trip origin and destination trip cost parking and toll regional or interregional travel vehicle miles traveled trip start and end time may all be determined by either post processing of the data or by respondent input The GPS ATD satisfies the needs of the modern longitudinal travel survey System Implementation Table 7 shows the hardware requirements to implement the features in Table 8 The Central Processing Unit CPU s a 32 bit 266 MHz ARM chip with the program Flash layered on top of the CPU die for a smaller package This chip runs the embedded Linux operating system OS At boot up the program stored in the on chip Flash will be loaded into the 32 Megabyte MB Synchronous Dynamic Random Access Memory SDRAM for execution The internal 256 MB non volatile Flash stores the data shown in Table 8 In general the GPS data 1s sampled once per second 1 Hz parsed and the pertinent data stored in an efficient binary format in Flash The other se
108. ravel Diary Systems using GPS amp New Technology CHAPTER 6 GPS ATD FIRMWARE The GPS ATD firmware consists of the Linux 2 6 kernel custom GPS ATD applications Trolltech Qtopia Core 4 uClibe 0 9 29 libraries and in house developed device drivers including bootloader NAND Flash storage keyboard lC inter integrated circuit USB interface and LCD Figure 26 shows the GPS ATD software layers Since all software components are either Open Source license or were developed in house the complete firmware could be made available under an Open Source license avoiding additional software licensing cost in mass production GPS ATD Main Application Qtopia Core 4 Libraries Runtime Environment Figure 26 GPS ATD firmware architecture The device s firmware image consists of a three stage bootloader and a runtime environment The main task of the bootloader is to initialize the CPU memory system and other hardware and to load and boot the kernel from NAND Flash It also supports various administrative functions via the serial port such as test and debug routines and flashing new firmware images The runtime environment is based on a Linux 2 6 kernel and a minimal GNU Linux OS Drivers and patches were developed against Linux 2 6 to support the following functionality 1 MX21 CPU Microtips LCD GPS ATD keypad Micron NAND Flash MT29F2G08AABWP and MT29F2GO8AACWP I C bus serial UART custom digital control lines YAFFS2 file syst
109. rritory of the United States The FAA commissioned the Wide Area Augmentation System at 12 01am on July 10 2003 At present there are two geo stationary satellites Inmarsat IIIs serving the WAAS Pacific Ocean Region POR and Atlantic Ocean Region West AOR W The FAA s pursuing dual geo satellite coverage throughout the U S to eliminate a possible single point of failure and increase system reliability The West Coast currently has dual satellite coverage as can be seen in Figure 1 Although WAAS was originally designed for aviation use it provides benefits beyond aviation to all modes of transportation including maritime highway and rail Small low power WAAS enabled GPS receivers are more widely available than NDGPS enabled GPS 28 Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology receivers WAAS vertical accuracy over the United States is illustrated in Figure 2 horizontal accuracy of most interest for travel surveys is approximately three times better than vertical due to geometric configuration As with coverage the West Coast has excellent WAAS accuracy ja Pall LE 3 POR Figure 1 WAAS geostationary satellites coverage map http gps faa gov CapHill geosat htm Ls Pr P P T 5 7 bi E oy m Latitude LP Service Contour solid red line LHAV VHAV Service Contour dashed bla
110. s Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology TRIP ACTIVITY Table 5A Active Mode User Input 88 Strikethrough are confidential fields Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology RAE Home 1 Working at home related to primary or second job 1 gt REA Shopping at home ordering by telephone or internet from TV Internet promotions 3 Otherathome aa EN Travel 3 Get on vehicle Wait for a ride y 2A 2 NN Leave Parka vehicle 0 0 0 0 000000 000000 SME Boarding airplane rail intercity bus 6 Deboarding airplane rail intercity bus 4Pick upDrop off T7______ Pick up someone or get picked up ff of person z 1 1 gt NE _Drop off someone or get dropped off of person 1 00 Work o oo 9 Work include regular scheduled and volunteer work 1 10 Work related sales calls business meeting errand travel etc Education Childcare __ O 11 School preschool K 12 grad NN School post secondary college vocational 1 13 Childcare day care before after schoolcare SEE Dining _ 14 Eat out restaurant ete 0 1 Drive through a _
111. s by Caltrans TSI personnel during the evaluation process After selecting the Test config menu the administrator will see the menu shown in the following figure The administrator can test the GPS delete data logs change diary mode active hybrid and passive or display the firmware version as shown in the figure below Copyright 2011 AHMCT Research Center UC Davis GPS Automated Travel Diary User Guide ja 1 are joe pale re imd qe lat 38 32 0953 N long 121 45 2128 w UTC 06 05 05 sats 04 Retum fo main menu Under the GPS test sub menu the GPS ATD will display the current user position time and number of satellites used as shown above Under the Logging sub menu the administrator can enable or disable GPS logging and erase all previous logs used when the internal flash storage 1s full as shown above Copyright 2011 AHMCT Research Center UC Davis GPS Automated Travel Diary User Guide Under the Change diary mode sub menu the administrator can switch the GPS ATD into Active Hybrid or Passive mode as shown above Under the Firmware version sub menu the unit displays the current firmware version Each GPS ATD also has a serial number located on the bottom of the device Other menu selections may be available to support diagnostics by AHMCT personnel These should not be used except by AHMCT Copyright 2011 AHMCT Research
112. se Navigation FV 25 ATMEL u blox ANTARIS chip and Holux GPSlim236 SiRF III GPS chipset Generally all the tested GPS performances achieved similar performance under relatively open sky such as on highways and suburban residential streets The effect of trees on residential streets was comparatively small vs previous generations of GPS All GPS test candidates were able to provide good positional solutions under heavy tree cover The SiRF III chipset GPS was able to maintain lock to all GPS satellites in view while other chipset GPS could lose lock on some GPS satellites n view Figure 6 GPS test setup On the other hand performance varied significantly under GPS challenge conditions such as urban canyon Inside parking structure under a bridge and indoors Firstly the Garmin 18 and Atmel ANTARIS GPS chipset GPS lost track of GPS satellites when placed under any large structure such as a bridge The Atmel ANTARIS GPS stopped providing solution when it lost track of GPS satellites However the Garmin 18 provided a typically poor extrapolated solution based on previous speed and heading for several seconds Based on these results these receivers were eliminated from further testing 44 Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology 7 Image 2007 DigitalGlobe po Figure 8 Bridge test results for SI
113. shman to senior D 7 Graduate or professional school e g medical dental or law school _ 8 Trade Vocational Os Postgraduate a R 0 Military Advanced training o u ll Other specify 0 99 DontKnow Refused NENNEN Person X Work Address E ae Tm E TEE DemetaeeeptaP O Box number 1 D 2 OWY ooo P 3 County ma E RANA gt gt 5 Zip code 83 Strikethrough are confidential fields Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology 84 Strikethrough are confidential fields Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology PERSON INFORMATION Table 2 continued Pre Entered Data Person X Industry of Employment Industry of O 00 ISI9N N db m Professional Scientific Management Administrative and Waste Management Services Arts Entertainment Recreation Accommodation and Food Public Administration Government Person X Occupation Occupation of primary job Sales and Office Occupations Person X Class of Worker Class of worker of primary job Private wage and salary workers Govern
114. st in dollar amount Toll Pay Method l Cash 2 Fastrak 3 None 4 Subsidized 9 Other Transit Cost Ordinal Variable Transit Fare l Single Fare 2 Daily 3 Weekly 4 Monthly J Quarterly 6 Annually 1 None 8 Subsidized 9 Other Transit Information Text Station of access How long does it take you in minutes to walk to this station Text Station of egress How long does it take you in minutes to walk to your final _ destination Wait time at the station Ordinal Variable Number of transfers Is this your final destination 92 Strikethrough are confidential fields Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology APPENDIX B GPS ATD MENU FLOWCHART 93 Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology 94 Copyright 2011 AHMCT Research Center UC Davis GPS Automated Travel Diary User Guide GPS ATD Active Mode Menu Flowchart If mode selection is Auto truck van Motorcycle or Other Please select a trip activity sub category Home Please select a trip Number of passengers including yourself Yes less han 1 00 Yes 1 00 1 99 Yes 2 00 2 99 Yes 3 00 3 9
115. t Package Configurations and Deployment 74 Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology Plans in 9th International Association of Travel Behaviour Research Conference Queensland Australia July 2000 34 J Wolf R Guensler S Washington W Sarasua C Grant S Hallmark M Oliveira M Koutsak R Thittai R Funk and J Hsu Development of a Comprehensive Vehicle Instrumentation Package for Monitoring Individual Tripmaking Behavior Final Report Georgia Tech Rept GTI R 99005 1999 35 J Zmud and J Wolf Identifying the Correlates of Trip Misreporting Results from the California Statewide Household Travel Survey GPS Study in Orh International Conference on Travel Behaviour Research Lucerne August 10 15 2003 75 Copyright 2011 AHMCT Research Center UC Davis Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology APPENDIX A GPS ATD MENU TABLES as provided by Caltrans Division of Transportation System Information FE Copyright 2011 AHMCT Research Center UC Davis Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology HOUSEHOLD INFORMATION Table 1 Pre
116. t 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology ABSTRACT This report provides an overview of travel surveys including literature review and background as well as the motivation for the research and development of the Global Positioning System Automated Travel Diary GPS ATD The system requirements and specifications for the device development are presented and discussed In addition the detailed architecture hardware software and user interface design are included Vehicular and personal GPS ATD systems were developed to support comprehensive traveler behavior studies The GPS ATD provides an intuitive user interface to capture trip activity information trip purpose travel mode etc with minimal user input and burden during travel surveys Each survey participant interacts with their own personal GPS ATD and information is automatically coordinated between personal and vehicular GPS ATD units via ZigBee wireless The system captures and logs data from the High sensitivity GPS HSGPS receiver allowing subsequent identification of corridors route lengths and regional and inter regional trips The primary sensor 1s the HSGPS receiver For the vehicular GPS ATD inertial sensing MEMS gyro and accelerometers is also provided to fill in the gaps during GPS outages and cold starts To obtain vehicle sensor information the GPS ATD us
117. tain Technologies Inc according to AHMCT design specification These switches are connected to the built in keyboard interface of the 1MX21 ARM processor In addition it has an adhesive back that 1s used to fasten onto the top cover recess area of the GPS ATD plastic case A window opening for the LCD display was designed into the membrane cover Furthermore the keypad has a three inch built in ribbon cable with a I mm pitch zero insertion force ZIF connection at the end The ribbon cable is passed through an opening in the top cover and connected to the main circuit board during assembly Details of the custom membrane switch are available in a supplement _ J B Ho a Window cutout for 12 mm 340 g force LCD display stainless steel dome Imm pitch ZIF connection d Figure 16 GPS ATD membrane switch user keypad A monochrome 8 bit grayscale LCD with 240x160 resolution and built in electroluminescent EL backlight was selected due general readabil ty in all light conditions A color LCD display would require much brighter backlight under bright sunlight conditions and thus would decrease battery life The high resolution displays text clearly for the user A touch screen interface was not employed because it tends to 55 Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology add glare and adv
118. tandard specification or regulation xili Copyright 2011 AHMCT Research Center UC Davis Copyright 2011 AHMCT Research Center UC Davis GPS Automated Travel Diary User Guide LIST OF ACRONYMS AND ABBREVIATIONS CPU Central ProcessingUnit EID Electronie Travel Diary Liquid Crystal Display CP ET C NDGPS On Board Diagnostics U D D D I D C T XV Copyright 2011 AHMCT Research Center UC Davis GPS Automated Travel Diary User Guide SECTION I WELCOME amp INTRODUCTION Included accessories e AC adapter e Auto charger adapter e USB cable with mini B USB connector only included for Authorized Administrators Copyright 2011 AHMCT Research Center UC Davis GPS Automated Travel Diary User Guide e GPS ATD A w tr SR my A 4 44 4 Pa T S NUT og X a Y gt hd WARE f oc O e GPS ATD user manual this document About the GPS ATD The GPS ATD is specially designed to conduct a travel survey and reduce users burden It prompts the user travel survey respondent with questions and allows the user to select the appropriate answer from a list It has a built in GPS to automatically log the user s travel path All data are stored internally in flash memory The data are vigorously protected again any unauthorized downloading Copyright 2011 AHMCT Research Center UC Davis GPS Automated Travel Diary User Guide
119. tenna and GPS module are then hand soldered The complete GPS ATD s then assembled with the board LCD and battery placed into the 60 Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology plastic case as shown in Figures 24 Finally another series of full system validation tests are performed on the complete GPS ATD unit In large volume production a pick and place machine would dramatically speed up the assembly process However it would require an extensive one time machine programming and physical machine setup The time and cost of board assembly largely depends of the number of parts on the board LUND Figure 23 GPS ATD circuit board fixture for applying RoHS solder paste 61 Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology Figure 24 Fully assembled GPS ATD bottom side circuit boards qty 10 shown TATE z i s NC TEXIPERM X Hai Ft 4 RT 1 PSS we wt i 1 a 4 j Cial STE hi ihe IATNTE i Tun is Li zw i lt E TER PE PES m FIT z 1 i a TAREE TURR H 1 Figure 25 Fully assembled GPS ATD unit internals 62 Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal T
120. th two individual trips with same origin and destination using different route 2200002 10000000000000000000000000000000000000000000000000000000000000000000000000000006 70 Figure 34 Trip information displayed in Google Earth example short trips often not reported 70 1X Copyright 2011 AHMCT Research Center UC Davis Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology LIST OF TABLES Table 1 Fixed static information collected in a travel survey 0020000000000000000000000000s0ssssssnnnnsnnnnnnnnse 21 Table 2 Dynamic travel diary information collected for given trip s 21 Table 3 Summary of previous travel surveys 222200000000000000000000000000000000000000000000000000000000000000000000000000000 22 Table 4 Summary of previous GPS aided travel survey diary hard ware 23 Table 5 System features a R pese I E UNI NI MES 36 Table 6 Comparison of vehicular and personal versions of GPS ATPD 3 Table 7 GPS ATD system hardware eese cipe Seer tete b aid Eri ee Eo Ee ge AP Tee Ungu 39 Table 5 Data elements and update rates esi pies etae en inet ale hehe 40 Table 9 Feature cost benefit tradeoff analysis eee e eee eee e eee eee eene eee eee
121. tion of this noise depends on proper design of the various switching power supplies as well as the selection of bypass capacitors at device operating frequencies Substantial analysis and simulation of the system components were needed to determine the optimum set of bypass capacitors with the goal to select low ESR equivalent series resistance capacitors that are resonant at the noise frequency in question thus shorting that frequency to ground These bypass capacitors were then populated throughout the PCB and placed as close as possible to the supply pins of the various integrated circuit chips As the noise frequency being bypassed increases the distance between the bypass capacitors and supply pin must decrease At 266 MHz the bypass capacitors must be within 10 mm of the supply pin However at 33 MHz the bypass capacitors may be moved up to 100 mm away from the supply pins Since the PCB is smaller than 100 mm in any dimension the bypass capacitor can be placed anywhere on the board for any frequency below 33 MHz Proper noise control 1s not only important for digital circuitry but extremely important for analog circuitry Power supply noise In most analog circuits is modulated into the analog signal In the case of low noise amplifiers LNA used in the front end of low sensitivity GPS receivers the power noise would directly affect the signal to noise ratio of the received GPS signal and reduce the sensitivity of the receiver Therefore adequ
122. top layer and all power supplies bypass capacitors pull up resistors and simple control circuitry were placed on the bottom layer The main placement constraints were the location of the GPS RF circuitry which had to be in the upper left corner based on the case design and the ZigBee IC s and antenna which had to be placed at the other end Naturally the CPU was placed in the middle of the PCB since it connects to almost everything and based on timing noise constraints the SDRAM was placed as close as possible to the CPU Also the level transceiver and the NAND Flash were placed relatively close to the CPU Other system IC s were placed as space permitted with the pull up resistors and capacitors spread around the PCB following the rule for maximum distance between bypass capacitors and supply pins described above Our typical trace space trace width and trace spacing was 0 1 mm for all signal lines This value was not arbitrarily chosen rather t was a result of layout dependencies of the 14x14 mm 0 65 mm pitch CPU Ball Grid Array BGA and the PCB layer count since we sought to keep the PCB layer count low for cost considerations we chose a 6 layer 0 062 thick PCB stack up Primarily the PCB stack up would be made of the top and bottom component layers a power layer a ground layer a vertical signal layer and a horizontal signal layer With the CPU package having a pitch of 0 65 mm we chose via holes to be 0 2 mm in 0 35 mm pads with
123. ts with their own personal GPS ATD and information is automatically coordinated between personal and vehicular GPS ATD units via ZigBee wireless The system captures and logs data from the High Sensitivity GPS HSGPS receiver allowing subsequent identification of corridors route lengths and regional and inter regional trips The primary sensor is the HSGPS receiver For the vehicular GPS ATD inertial sensing MEMS gyro and accelerometers is also provided to fill in the gaps during GPS outages and cold starts To obtain vehicle sensor information the GPS ATD uses ZigBee wireless communications to the car computer On Board Diagnostics connector OBD II Following the design discussion complete system testing results and user feedback are discussed The report concludes with recommendations for future work related to the GPS ATD and its use in the 2010 California Statewide Household Travel Survey 17 Key Words 18 Distribution Statement Longitudinal travel surveys GPS MEMS IMU No restrictions This document is available to the human machine interface HMI highway public through the National Technical Information maintenance Service Springfield Virginia 22161 20 Security Classif of this report 20 Security Classif of this page 21 No of Pages 22 Price Unclassified Unclassified 148 Form DOT F 1700 7 8 72 Reproduction of completed page authorized PF V2 1 6 30 92 Copyright 2011 AHMCT Research Center UC Davis Copyrigh
124. ttons The user make menu choices with the application specific keypad This interface will be intuitive fast and result in reduced user burden In interactive mode an automatic sequence of requests for data could be made after the car 1s started in the case of the vehicle unit or by simply pressing a start button in the case of the wearable personal unit The wearable personal GPS ATD captures all modes of transportation In addition it is light weight and has rechargeable batteries that can be recharged from either the home station or an auto charger Its GPS receiver antenna is less sensitive to orientation several mounting and carrying options for the personal GPS ATD are provided to let the respondents use the unit in many situations walking biking and motorcycling with ease The vehicular GPS ATD has additional sensors OBD II interface and backup batteries which are rechargeable from vehicle power The heart of the system uses a HSGPS receiver for positional data collection When a GPS system initially starts up or suffers intermittent satellite signal loss dead reckoning can be used to supplement the positional data This data is calculated from MEMS inertial sensor gyroscope and accelerometers measurements during a loss of positional fix by the GPS receiver As shown in Table 8 the sample rate of these sensors will be increased during the GPS blackout interval Larger backup batteries can power the GPS receivers for extended perio
125. tware and user interface design are included Vehicular and personal GPS ATD systems were developed to support comprehensive traveler behavior studies The GPS ATD provides an intuitive user interface to capture trip activity information trip purpose travel mode etc with minimal user input and burden during travel surveys Each survey participant interacts with their own personal GPS ATD and information is automatically coordinated between personal and vehicular GPS ATD units via ZigBee wireless The system captures and logs data from the High Sensitivity GPS HSGPS receiver allowing subsequent identification of corridors route lengths and regional and inter regional trips The HSGPS receiver 1s the primary sensor For the vehicular GPS ATD inertial sensing MEMS gyro and accelerometers 1s also provided to fill in the gaps during GPS outages and cold starts To obtain vehicle sensor information the GPS ATD uses ZigBee wireless communications to the car computer On Board Diagnostics connector OBD II Following the design discussion complete system testing results and user feedback are discussed The report concludes with recommendations for future Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology work related to the GPS ATD and its use m the 2010 California Statewide Household Travel Survey vi Copyright 2011 AHMCT R
126. uisition and re acquisition time e and positional solution availability in various GPS challenge conditions such as inside buildings concrete parking structures household garages in urban canyons and under heavy tree cover GPS World magazine provides a comprehensive list of existing GPS equipment makers in its annual survey this served as a basis for the selection process The GPS ATD requires the use of a small and low power GPS module to keep the size and weight down while providing long run time using battery power Therefore any GPS sensors bigger than 2 sq inches or consuming more than 200 mW were eliminated Following GPS World s GPS hardware list each manufacturer s product line was examined in detail to dentify likely candidates In addition web searches were carried out to find other GPS modules makers not on the GPS World annual survey Due to the rapid change in technology and roll out of new GPS chipsets most printed GPS test results are quickly out of date and obsolete On the other hand GPS enthusiast websites such as http www gpspassion com provide current GPS news and test results for popular GPS receivers as well as industry trends The GPS industry is very much like the computer industry Even though there are many computer makers there are only a few CPU makers Similarly there are relatively few GPS chipset makers the chipset 1s the processing engine of the GPS receiver GPS receivers using the same GPS chi
127. und in digital cameras and mobile phones 54 Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology To maintain low unit cost a COTS ABS plastic case part 1593TBK made by Hammond Manufacturing was selected The case is composed of three pieces Each case top cover requires CNC machining to create the LCD display window opening keypad connection opening and recess for the LCD display Two different case front panels were CNC machined for the vehicular and personal version of GPS ATD In the case of the personal GPS ATD openings for the mini USB connector and GPS antenna are required For the vehicular GPS ATD openings for the mini USB connector and GPS antenna MCX connector were machined into the front panel A custom fixture was designed and fabricated to speed up the CNC machine process All the mount posts in the case interior top and bottom cover are removed to allow room for the circuit board battery and LCD display Details of the 1593TBK modifications are available in a supplement A custom membrane switch was found to be the most cost effective and esthetically pleasing way to add a custom user interface hence a custom membrane switch was designed and manufactured for the GPS ATD It has four application specific spherical embossed buttons with 12 mm diameter 340 g force stainless steel dome custom made by Intermoun
128. ve achieved the goals of the Stage I study and provide substantial data collection benefits and reduced user burden a survey using these units will produce large and complex sets of spatiotemporal data Analysis of this data will require development of appropriate techniques and tools to support and facilitate extraction and reporting of useful survey data These tools will enable planners to effectively search and query the large set of data to generate general statistics The final results of this Stage II effort will be the needed analysis tools to support data extraction and reporting of survey results as well as a much larger set of enhanced prototype GPS ATD units all ready for transition to deployment and or commercialization and for use in the Caltrans 2010 Longitudinal Travel Behavior Survey 12 Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology 10 11 12 13 14 15 16 17 18 REFERENCES Battelle Transportation Division Personal Travel Unit PTU Development and Initial Testing Federal Highway Administration 2000 P Bullock P R Stopher G Pointor and Q Jiang GPS Measurement of Travel Times Driving Cycles and Congestion Institute of Transport Studies University of Sydney Rept ITS WP 03 07 Sydney Australia 2003 J Casas 2000 2001 California Statewide Househo
129. versal Longitudinal Travel Diary Systems using GPS amp New Technology LIST OF ACRONYMS AND ABBREVIATIONS ASCII American Standard Code for Information Interchange Ball Grid Array California State Department of Transportation CASI Computer Assisted Self Interview CATI Computer Assisted Telephone Interview CDMA Code Division Multiple Access Computer Numerical Control COTS Commercial Off the Shelf L CPU Central Processing Unit Digital to Analog Converter D F Dilution of Precision Department of Transportation Dead Reckoning DOD DepartmentofDefene DOP DOT DR DRI Division of Research and Innovation po DP Digital Subscriber Line EL TCC Electroluminescet EMI Electromagnetic Interference BSR BD FAA FBGA Equivalent Series Resistance FBGA FM B Gigabyte GS Geographic Information System IC Integrated Circuit Inertial Measurement Unit L HS 4 Intelligent Transportation Systems ITSA Intelligent Transportation Society of America IV IneligentVehide S MB J J Megabyte 5 0 0 MEMS Micro Electro Mechanical Systems Frequency Modulation NC CPU AC OT DR DRI DSL EL EMI ESR ETD AA FM GB GIS SM MI IC MU ITS IV CD MB Copyright 2011 AHMCT Research Center UC Davis Development o
130. y of a GPS receiver to track satellites Typically lower elevation GPS satellites signals are most likely to be blocked In this situation GPS receivers track only the highest satellites in the sky as opposed to those satellites which provide the best Dilution of Precision DOP a measure of the satellite geometry error sensitivity Thus the positional accuracy decreases Unfortunately there will be locations where the minimum required four GPS satellite signals simply are not available due to obstruction such as urban canyon 4n these cases no general GPS solution can be obtained GPS Sensors There are many GPS receiver manufacturers some options and form factors are shown in Figure 3 Each manufacturer may have its own signal tracking positional solution and filtering algorithms Receivers may perform differently during startup reacquisition of signal and in various terrains such as urban canyons and under tree canopies Nevertheless most GPS receivers output the position and time solution in ASCII text standard National Marine Electronics Association NMEA 0183 format via an RS232 serial port NMEA output sentences contains Coordinated Universal Time UTC date and time latitude longitude and altitude in the WGS 84 coordinate system geoidal separation number of visible satellites speed heading horizontal DOP HDOP and solution status Some GPS receivers give additional information such as estimated positional accuracy M
131. y time by plugging the AC adapter to Copyright 2011 AHMCT Research Center UC Davis GPS Automated Travel Diary User Guide the GPS ATD power charging port located on the s de of the unit next to the GPS antenna shown in Figure 2 and 3 The user should then plug the AC adapter to the AC wall outlet The unit may also be charged with an Auto charger adapter using any 12 VDC vehicle power outlet It takes approximately four hours to fully charge a completely discharged internal battery The GPS ATD has battery management circuitry to prevent over charging or discharging of the internal Lithium Ion Battery The user can charge the battery at anytime The GPS ATD has no off switch It turns tself off when the battery is low Figure 3 Charging the GPS ATD Copyright 2011 AHMCT Research Center UC Davis Copyright 2011 AHMCT Research Center UC Davis GPS Automated Travel Diary User Guide SECTION 3 SETUP Setup should only be performed by trained authorized personnel Data can be lost permanently if setup is performed incorrectly The very first screen menu will show Begin a new trip or Test config menu as shown below The Test config menu will not appear in the final version of the firmware of the GPS ATD as sent to the end users The Test config menu s made available to allow easy change between Active Hybrid and Passive modes refer to the main project report for discussion of mode
132. ystem Theory and Practice Springer Verlag New York 2001 R Kitamura and T van der Hoorn Regularity and Irreversibility of Weekly Travel Behavior Transportation 14 pp 227 251 1987 F S Koppelman and E I Pas Estimation of Disaggregate Regression Models of Person Trip Generation with Multiday Data in Proceedings of the Ninth International Symposium on Transportation and Traffic Theory Utrecht The Netherlands pp 513 529 1984 G Lachapelle H Kuusniemi D T Dao G MacGougan and M E Cannon HSGPS Signal Analysis and Performance under Various Indoor Conditions in Institute of Navigation GPS Conference Portland OR September 9 12 2003 O P Leisten and A P Wingfield Commitment to Design for a Safety Critical Function Reliable GPS Antenna Technology for E 911 in Handsets in Institute of Navigation GPS Conference Portland OR September 9 12 2003 M G McNally J E Marca C R Rindt and A M Koos GPS GIS Technologies for Traffic Surveillance and Management A Testbed Implementation Study California PATH Rept UCB ITS PWP 2002 7 2002 O Mezentsev Y Lu G Lachapelle and R Klukas Vehicular Navigation in Urban Canyons Using a High Sensitivity GPS Receiver Augmented with Low 73 Copyright 2011 AHMCT Research Center UC Davis Development of Vehicular amp Personal Universal Longitudinal Travel Diary Systems using GPS amp New Technology 19 20 21 22 23 24 25 2

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