indoor positioning with a view to team sport track- ing
Contents
1. WAKEUP Ba IROn R41 DNF 00 D D 3V6 DW1000 SUBSYSTEM DNF 109 SEES SPIVF J6 POWER SUBSYSTEM SPI VF to POWER SOURCE Always computer SELECTION Connected ARM SUBSYSTEM 5 V DC input from USB J5 USB Connector FIGURE 19 Logical View of EWB100 27 29 During the project the SPI channel was used to communicate with a DW1000 chip by computer via an SPl adapter Figure 20 S2 switch needed to be turned off to have a straight channel to a DW1000 subsystem Switching off S2 enabled to avoid connection to the ARM subsystem which would have been pointless in this case SPI adapter J6 SPI header FIGURE 20 External Application control using SPI External Header 27 3 1 Bus Pirate v3 6 Bus Pirate is an open source SPI adapter which can be used to communicate with electronics from a PC serial terminal Figure 21 Bus Pirate v3 6 was used during the project because it has an SPI bus traffic sniffer the manual is well documented cost effective open source and scriptable from a Python program ming language It is also easy to connect to a computer via a USB connector Bus Pirate v3 6 was developed by a US company called Dangerous Prototypes 28 30 FIGURE 21 Bp Protocol of Bus Pirate 28 3 2 Ubuntu 14 10 The software itself was implemented on an Ubuntu 14 10 operating system Ub untu is an open source operating system developed by Canonical2. 51 29 m 52 45m 53 37 m 54 00 m 54 40 m 54 65 m 54 67 m 43 6 CONCLUSION Currently radio technologies seem to be a better option for sport tracking sys tem than non radio technologies because they are more accurate in the indoor environment Comparing different types of radio technologies the ultra wide band came prominence because of the accuracy multipath communication and cost The methods used with an ultra wideband are typically the TDOA and the AOA The future sport tracking indoor positioning system needs for sure a pre installation of infrastructure because it will not be able to use the already exist ing wireless network The conclusion of the experimental evaluation of the Decawave s EVK1000 evaluation board was that it needs a custom software and better antennas to be more accurate The first experiment with a passive target and in a low speed mode was better than was expected The biggest error value was 1 1 centime ters during the first experiment The second experiment was worse than was expected because the range of signal decreased from 100 meters to 22 meters when turning the slow speed mode of the response time to a high speed mode The shortening of the range was known but the magnitude of the change was unexpected In the third experiment the task was to evaluate an active target with a maximum velocity of 20km h The experiment proved that the EVK1000 is not
3. 2 2 3 The Received Signal Strength Indicator RSSI The power of a signal travelling between two nodes contains a signal parameter which is valuable information for estimating a distance between the nodes 5 RSS can be equivalently reported as the squared magnitude of the signal It can be related to positioning purposes if its path loss model is known 8 The RSSI method is similar to the TOA method because it also uses a triangulation to lo calize the target node Figure 4 However instead of using the time of arrival the system uses the received signal strength The strength of the received signal determines the distance travelled by the signal 7 Usually the RSSI method is used with RF signals such as WLAN or Bluetooth 11 One of the disadvantages of the RSS method is shadowing and a small scale channel effect causing the random deviation from the mean received signal strength therefore the technigue is less accurate than other technigues 7 The following formula can be used to estimate the effect of multipath fading and shad owing PL PL 10logio d 5 FORMULA 3 PL represents the total Path Loss between the Receiver and Transmitter must be bigger than zero PL represents the reference path loss in dB when distance is 1 meter and this must be specified as greater than or equal to zero d represents the distance between the transmitter and receiver in meters n represents the path loss exponent for the environment
4. s represents the standard deviation associated with the degree of shadow fad ing present in the environment in dB 9 Another disadvantage is that RSS needs an accurate global reference power for all positions because an antenna does not transmit signals with equal power in all directions The RSS method is not suitable for large buildings because it highly reduces the accuracy The RSS technique is cheap and easy to obtain with low complexity algorithms Clock bias do not exist in RSS systems therefore there is no need for an expensive time synchronization 8 15 d distance al a2 anchor x target FIGURE 4 The d represents the Distance in Error free Case between Center Node and the Target Node located on the Circle 2 2 4 The Angle of Arrival AOA The angle of the arriving signal can be estimated by estimating the AOA param eter of a signal traveling between the nodes 5 To estimate the angle of the received signal requires antenna arrays at the target node The AOA offers com plementary technique beside the RSS technique by using directional information 8 Like in the TOA and the TDOA also in the AOA method all anchor nodes should be known However the AOA method requires only two anchors along with two AOA measurements 3 The first advantage of the AOA technique is that there is no need for the expen sive time synchronization since the AOA of one anchor receiver pair is obtained using the pseudo range differ
5. K 2004 Geolocation by time difference of arrival us ing hyperbolic asymptotes Acoustics Speech and Signal Processing 2004 Proceedings ICASSP 04 IEEE International Conference on IEEE 11 Mautz R 2009 Overview of current indoor positioning systems Geodezija ir kartografija 35 1 18 22 12 Randell C Muller H 2001 Low cost indoor positioning system Ubicomp 2001 Ubiquitous Computing Springer 13 Liu H Darabi H Banerjee P Liu J 2007 Survey of wireless indoor posi tioning techniques and systems Systems Man and Cybernetics Part C Appli cations and Reviews IEEE Transactions on 37 6 1067 80 14 Mautz R 2012 Indoor positioning technologies Habilitation Thesis ETH Zurich Zurich Switzerland 15 Goswami S 2012 Indoor location technologies Springer Science amp Busi ness Media 16 Gu Y Lo A Niemegeers 2009 A survey of indoor positioning systems for wireless personal networks Communications Surveys amp Tutorials IEEE 11 1 13 32 17 Li B Gallagher T Dempster AG Rizos C 2012 How feasible is the use of magnetic field alone for indoor positioning International Conference on In door Positioning and Indoor Navigation 18 Woodman OJ 2007 An introduction to inertial navigation University of Cambridge Computer Laboratory Tech Rep UCAMCL TR 696 Pages 14 15 19 Titterton D Weston JL 2004 Strapdown inertial navigation technology IET Page 2 48 20 Wils
6. The magnetic positioning uti lizes surrounding generated magnetic fields Magnetic fields can be generated either from permanent magnets or from coils It is also possible to combine an electric field and a magnetic field for positioning purposes 14 The best advantage of the magnetic field positioning is that there is no need for deploying infrastructure 17 Implementing the magnetic positioning system is relatively cheap compared with other positioning systems The sensors are small therefore they do not need much space The magnetic based positioning sys tems offer a multi position tracking 16 Using fingerprinting gives a more accu rate estimation in magnetic positioning Fingerprinting is useful if a signal propa gation is unpredictable or a direct line of sight propagation is not typical 17 The disadvantage of the magnetic based system is that there is only a limited cover age range Increasing the coverage range area requires further development 16 Also electronic devices or moving objects containing ferromagnetic materi als may affect the magnetic field and therefore cause an error in estimation Ad ditionally the intensity data of the magnetic field consist of only three intensities in X Y and Z directions 17 19 2 3 1 2 Inertial Navigation Inertial navigation systems INS are sophisticated autonomous electromechan ical systems which supply the position velocity and attitude of the object in which they
7. The ra dio frequency range is around 3 kHz to 300 GHz Figure 11 The most difficult parts of the development of the radio based indoor positioning system are multi path and shadow fading The functionality of the radio based indoor positioning 22 system relies on the availability of a line of sight LOS 4 Also if the chosen radio technology needs the pre installation of infrastructure or fingerprinting da tabase etc the implementation is difficult slow and expensive 1 Energy increases Short wavelength Long wavelength WV VV V N VV VA 105 nm 10 nm 1nm 102 nm 105 nm 1m 103 1 1 1 wei 1 1 1 5 5 Ultraviolet Infrared Microwaves Radio waves 10 Hz 107Hz 10 Hz 10 8 2 10 5Hz High frequency 10 Hz 10 Hz 108 Hz 105Hz 10 Hz 10 Hz Low freguency Visible light 7 x 10 Hz 4 x 10 Hz FIGURE 11 Electromagnetic spectrum 2 3 2 1 Bluetooth The Bluetooth is a short range data communication protocol which is also known as the IEEE 802 15 standard 21 The range band of the radio fre quency of the Bluetooth is from 2 4 to 2 485 GHz 22 Figure 12 The Blue tooth positioning system is one of the network based positioning systems and can also be categorized as LPS Bluetooth devices contain mini cells which have a strong effect on accuracy 21 Wavelength 100 1um 10 um 100 um 1mm 10mm 0 1m im 10m 100m 1km UV Infrared Microwave
8. conditions due to a shadow fading and multipath fading 4 2 2 1 Time of Arrival TOA The time of arrival of the received signal is the most important parameter in an accurate indoor positioning system 7 The time of arrival estimation allows the measurement of distance in an indoor positioning system In the TOA method the anchor nodes use a triangulation to localize the target node The anchor nodes can be static or dynamic It is assumed that the positions of all static anchor nodes are known If the anchor nodes are dynamic there is a need to use GPS to local ize the anchor nodes all the time TOA requires the anchor nodes and target nodes to work synchronized 3 The estimation of TOA requires a very accurate timing reference at the target node which needs to be synchronized with the clock at the anchor nodes The distance between a target node and an anchor node can be obtained by multiply ing the TOA with the speed of light 8 A small timing error in the indoor position ing system which uses the TOA may cause a large calculation error of the dis tance When running the system each transmitted signal needs to be labeled 11 with own timestamp in order to determine the time when the signal was initiated at the target node 3 The TOA value can be estimated by the following formula D FORMULA 1 D represents distance in meters c represents the speed of light in m s t represents time in seconds 9 The advan
9. Community Help Wiki 2015 Date of retrieval 13 3 2015 https help ubuntu com community Minicom Minicom 1 49
10. System in an implemented Network Infra structure Another way is to use an already existing wireless network infrastructure to locate a target node Figure 18 The advantage of the second case is to avoid time consume and expenses in implementing a network infrastructure because it al ready exists However these two systems need intelligent algorithms to patch the low accuracy results for measured metrics 18 27 WAP Wireless access point T Target node FIGURE 18 Wireless Geolocation System in Existing Network Infrastructure 28 3 THE WORK ENVIRONMENT 3 1 Decawave DW1000 The DW1000 is a single chip transceiver which enables developers to imple ment cost effectively indoor positioning solutions The DW1000 is a fully inte grated low power single chip CMOS radio transceiver IC compliant with the IEEE 802 15 4 2011 ultra wideband standard The DW1000 consists of an ana log front end both RF and baseband containing a receiver and transmitter and a digital back end that interfaces to a host processor The measurement accu racy range of DW1000 is about 10cm 26 The DW1000 has been devel oped by an Irish company called Decawave DW1000 is attached to the EWB1000 evaluation board which can be used eas ily in development The EWB1000 evaluation board consists of DW1000 ARM and a power subsystem Figure 19 EWB1000 has four connectors USP SPI power and antenna connector 27 J1 Antenna Connector
11. 0 mechanical interferometry Sound cm 2 10 distances from time of arrival WLAN WiFi m 20 50 fingerprinting RFID dm m 1 50 proximity detection fingerprinting Ultra Wideband cm m 1 50 body reflection time of arrival High Sensitive GNSS 10m global parallel correlation assistant GPS Pseudolites cm dm 10 1000 carrier phase ranging Other Radio Frequencies m 10 1000 fingerprinting proximity Inertial Navigation 1 10 100 dead reckoning Magnetic Systems mm cm 1 20 fingerprinting and ranging Infrastructure Systems cm m building fingerprinting capacitance Typical Application metrology robot navigation people detection tracking automotive metrology hospitals tracking pedestrian navigation LBS pedestrian navigation robotics automation location based services GNSS challenged pit mines person tracking pedestrian navigation hospitals mines ambient assisted living FIGURE 7 Overview of Indoor Positioning Systems 14 18 2 3 1 Non radio Technologies A number of different types of non radio technologies are used in indoor posi tioning such as ultrasound inertial systems imaging infrared etc 15 This pa per covers the most used non radio technologies in localization 2 3 1 1 Magnetic Positioning The magnetic positioning is a classic way of positioning tracking It offers a high accuracy positioning because it does not reguire the maintenance on line of sight LOS between the anchor and target nodes 16
12. 014 Distributed indoor positioning system with inertial measurements and map matching IEEE Transactions on Instrumentation and Measurement 63 11 2682 95 2 Yayan U Yucel H Yazici A 2014 A Low Cost Ultrasonic Based Position ing System for the Indoor Navigation of Mobile Robots Journal of Intelligent amp Robotic Systems 3 Zekavat SAR Buehrer R 2011 Handbook of Position Location Theory Practice and Advances 4 Pahlavan K Li X M kel J 2002 Indoor geolocation science and technol ogy IEEE Communications Magazine 40 2 112 8 5 Gezici S 2008 A survey on wireless position estimation Wireless Personal Communications 44 3 263 82 6 Fuchs C Aschenbruck N Martini P Wieneke M 2011 Indoor tracking for mission critical scenarios A survey Pervasive and Mobile Computing 7 1 1 15 7 Ali AA Omar A 2005 Time of Arrival estimation for WLAN indoor positioning systems using Matrix Pencil Super Resolution Algorithm Proceedings of the 2nd Workshop on Positioning Navigation and Communication WPNC 8 Yan J 2010 Algorithms for indoor positioning systems using ultra wideband signals Delft University of Technology 9 Wi Fi Location Based Services 4 1 Design Guide Location Tracking Ap proaches Design Zone for Mobility Cisco 2008 Date of retrieval 28 2 2015 47 http www cisco com c en us td docs solutions Enterprise Mobility WiFiLBS DG wifich2 html 10 Drake SR Dogancay
13. Ltd Ubuntu belongs to a Unix based Linux distribution package The mission of the Ubuntu development was to create a free software to everybody All volunteers were gathered together and therefore the first Ubuntu version saw the daylight in 2004 After many years Ubuntu still is and always will be free to use share and develop to everybody 29 The Ubuntu operating system was used in this project because it is an open source operating system and easy to set up 3 3 Minicom Minicom is a serial communication program for Linux operating systems The serial communication programs are used to send data one bit at the time over computer bus 30 Minicom was used as a communication tool between the computer and the hardware device EVK1000 in this project 31 4 CONFIGURATION The configuration started by installing a Minicom serial communication program on the Ubuntu operating system After installation the configuration of the USB port for Minicom needed to be set and saved as default When the configuration was completed the Bus Pirate SPI adapter was reguired to connect with the com puter via the USB bus Before connecting the EVK1000 with the SPI adapter it was reguired to configure the EVK1000 so that straight communication with the DW1000 was possible At first all the S1 dips of the EVK1000 board had to be set to off mode to enable the SPI connection Additionally the EVK1000 dips needed to be set so that the transmission speed of pa
14. OAM lt OULU UNIVERSITY OF APPLIED SCIENCES Niina M kinen INDOOR POSITIONING WITH A VIEW TO TEAM SPORT TRACK ING INDOOR POSITIONING WITH A VIEW TO TEAM SPORT TRACK ING Niina M kinen Bachelor s Thesis Spring 2015 Degree program in Information Technology Oulu University of Applied Sciences ABSTRACT Oulu University of Applied Sciences Information Technology Author Niina M kinen Title of thesis Indoor Positioning System with a View to a Team Sport Tracking Supervisor Pekka Alaluukas Term and year of completion Spring 2015 Pages 49 The need for indoor positioning is emerging but the expected breakthrough has not happened so far The lack of accuracy cost effectiveness and suitability for all kinds of use cases have been the main problems with current solutions Even though there are such amazing indoor positioning systems none of them has stood out like GPS in outdoor environments This document opens up a little bit the world of indoor navigation and points out the current issues of the most used indoor positioning systems The objective of this Bachelor s thesis was to find out the most proper design for a future sport tracking indoor positioning system The document covers well con sidered technologies methods and algorithms used in current indoor positioning systems This paper also provides an experimental evaluation of an ultra wide band based indoor positioning system The evaluation was done for D
15. Radio Freguency 3PHz 300 THz 30 THz 3THz 300 GHz 30 GHz 3 GHz 300 MHz 30 MHz 3MHz 300kHz FIGURE 12 The Black Line illustrates the Freguency Range of Bluetooth 14 23 Bluetooth technology is suitable for providing some limited communication with the positioning information but it has also an issue The disadvantage of Blue tooth technology is that the architecture of the system reguires a lot of expen sive receivers The accuracy of Bluetooth indoor positioning system depends strongly on the number and size of the cells in device 21 2 3 2 2 WLAN A wireless local area network is a typical network based LPS 21 WLAN is a wireless computer network that links two or more devices using a wireless distri bution method 1 The WLAN which is also known as the Wi Fi or the IEEE 802 11 standard is a higher bandwidth communication protocol than Bluetooth 21 WLAN operates at 2 4 GHz 3 6 GHz 4 9 GHz 5 GHz and 5 9 GHz bands 23 Figure 13 The range of the radio frequency of WLAN and Bluetooth over laps at 2 4 GHz However neither WLAN nor Bluetooth was implemented to deal with the interference that each creates for the other Overlapping may cause little issue when developing indoor positioning system with either of these technolo gies 24 WLAN is an older technology than Bluetooth therefore it is a little bit more sophisticated 21 Wavelength 100 nm 1um 10 um 100 um 1mm 10 mm 0 1m 1m 10m 100m 1km uv 1 Infrared i Mic
16. WLAN Universal Character Set U Transformation T Format F 8 bit is a character encod ing capable of encoding all possible charac ters in Unicode The encoding is variable length and uses 8 bit code units A wireless networking technology that al lows computers and other devices to com municate over a wireless signal 1 INTRODUCTION The last decades have seen the revolutionary development in positioning sys tems Especially the development of outdoor positioning systems has been sig nificant The indoor positioning systems have become very popular in recent years but still there is a lot to further develop them Some indoor positioning sys tems have been successfully used in different types of tracking or navigation pur poses However none of the current indoor positioning systems have become the most useful for any type of use cases like GPS in an outdoor environment GPS is not suitable for indoor positioning systems because the attenuation caused by roofs and walls affects the localization estimation Therefore the old indoor positioning systems such as magnetic positioning and inertial positioning systems which have many advantages have taken place early on However these technologies have also several disadvantages which caused the develop ment of indoor positioning systems based on radio technologies This document provides an overview of the most used radio and non radio tech nologies which could be proper fo
17. able to track at regular intervals and the longest distance for the first de tected signal was around 22 meters in a sleepy mode The plan of the indoor positioning system was mainly based on the information found from the sources of this document The radio signal technology used in this indoor positioning system will be ultra wideband The most suitable device found was the Decawave s EWK1000 evaluation board The method which will be used in this system is the TDOA method which draws hyperbolae curves The intersections of the hyperbolae curves are the coordinates of the target node The anchor nodes must be placed on the sides of the tracking area The anchor nodes do not need to be equally located on the sides but their clocks 44 need to be synchronized Each anchor node communicates with the target nodes and sends the information to the server where the data will be stored Figure 30 On the server side the data will be processed with algorithms and sent to a Ul layer where it will be displayed to the user The data is valuable in formation for example in team sport tracking anchor 2 anchor 3 Server anchor 4 1 anchor 86 anchor 85 FIGURE 30 The Plan of the Indoor Positioning System During my Bachelor s thesis learned a lot about different radio and non radio technologies which can be used in the indoor positioning systems They all have different types of pros and cons which affect signific
18. antly the architecture of the system also found out how to classify and compare the technologies and methods with each other This Bachelor s thesis helped one software com pany to select the right technology and methods and evaluate the analysis for the selected devices In the middle of the thesis learned how to configure and use the SPI adapter with the EWB1000 evaluation board also learned how to configure set up and change the response mode of the EWB100 evaluation board This Bachelor s thesis was interesting because the evaluated test anal yses proved that some of the found theories did not guite match with the anal yses However our test environment was not error free and thus the claims 45 cannot be fully supported Throughout this Bachelor s thesis cooperated with my project managers and followed the instructions carefully If had to do something differently would do the testing during the summer be cause now the weather was continually too bad for the devices The testing could have been done in an error free environment to get more accurate re sults This document holds all information from the technical perspective and it can be used to start the implementation of the ultra wideband based indoor positioning system Overall the Bachelor s thesis was successful and satisfac tory results were achieved 46 7 REFERENCES 1 Perttula A Leppakoski H Kirkko Jaakkola M Davidson P Collin J Ta kala J 2
19. are mounted Nowadays INS is used in many different applications including the navigation of an aircraft tactical and strategic missiles submarines ships and spacecraft 18 The operation of INS is based on the laws of classical me chanics formulated by Isaac Newton Newton s laws tell us that the motion of a body will continue uniformly in a straight line unless disturbed by an external force acting the body The laws also tell us that this force will produce a proportional acceleration of the body 19 In INS accelerometers and gyroscopes provide an ability to track the position and orientation of a tracking object relative to a known starting point orientation and velocity Inertial measurement units IMUs usually contain three orthogonal rate gyroscopes and three orthogonal accelerometers Figure 8 Orthogonal rate gyroscopes and orthogonal accelerometers measure the angular velocity and lin ear acceleration respectively in the system 18 The inertial navigation system relies on the availability of the knowledge of the starting point In order to navigate it is necessary to keep track of the direction of the accelerometer Figure 9 Gyroscopic sensors are used to determine the orientation of the accelerometer at all times 19 20 Stable platform Xh FIGURE 9 The Body and Global Frames of Reference of Inertial Navigation System 9 21 2 3 1 3 Ultrasonic In nature there are living creatures which have indepe
20. ckages was faster than the default to speed up the testing Finally the small cords of the SPI adapter were reguired to connect with right spikes on the EVK1000 board Figure 22 If some of the cords would have connected with a wrong spike it would have caused a short circuit in the worst case Figure 22 SPI Adapter connected with EWK1000 Evaluation Board After completing all hardware connections it was possible to start setting up SPI settings in Minicom prompt The working SPI settings were 32 e speed 1MHz e clock polarity idle low default e Clock output edge active to idle default e clock phase middle default e CS CS default e OUtput type normal After going through all settings the SPI channel was ready for use The development started with the MISO and MOSI testing to figure out if the con nections and settings were set up right MISO stands for Master In Slave Out which means to generate the Slave line for sending data to the master Mutually MOSI means Master Out Slave In and means to generate the Master line for sending data to the peripherals By sending an index value to master the re sponds were exactly the ones they were supposed to be and therefore the con figurations were successful Figure 23 vs o0o X X X Miso __ 0x30 0x01 spicsn FIGURE 23 MOSI and MISO Non indexed Read of Device ID Register 5 TESTING The aims of the testing were to find out h
21. e of distances of the points of hyperbola compared to two fixed points is a constant Therefore the intersection of two or more hyperbolae gives the loca tion of the target node 10 Figure 2 A TDOAg cC Target node FIGURE 2 Illustration of TDOA Estimation where Target Node esti mated by finding the Intersection of Two Hyperbolae Synchronization in a TDOA system is less expensive than synchronizing all the units in the TOA system because in the TDOA system there is a need to syn chronize only the anchors with known positions The TDOA is less accurate than the TOA system if they are using the same system geometry For example if in some case the vectors between the anchor nodes and the target node form a cone the localization of the target node is impossible Figure 3 The situation happens when there exists an unlimited number of possible values for the clock 13 bias corresponding to an unlimited number of possible positions of the target node However the TOA method is suitable for solving this type of cone sym metry positioning problem 8 A1 A2 T1 A Anchor node T Target node FIGURE 3 Geometry Symmetric Problem Case in Indoor Positioning System where the Anchor Nodes A1 A2 A3 A4 and the Target Node T1 form a SD Dimensional Cone By using the TDOA Method the Problem is Unsolvable but Instead of using the TOA Technique the Problem Case is possible to solve
22. e point located to a ceiling or on top of the positioning area Attenuation is a general term that refers to any reduction in the strength of a signal A wireless technology that enables commu nication between Bluetooth compatible de vices for short range typically less than 30 meters connections A fingerprinting algorithm is a procedure that maps a large data item to a much shorter bit string A Global Navigation Satellite System is a space based satellite system operated by the Russian Aerospace Defense Forces A Global Positioning System is a satellite navigation system used to determine the ground position and velocity in an outdoor environment An operating system based on UNIX that runs on many different hardware platforms 5 LOS MISO MOSI Multi paradigm language NLOS OSI RFID and whose source code is available to the public Line of Sight is an unobstructed view from a transmitter to a receiver The accuracy of the radio technologies relies on the LOS be tween nodes Master In Slave Out MISO Slaves gener ates MISO signals and the recipient is the Master Master Out Slave In MOSI MOSI signal is generated by the Master the recipient is the Slave A multi paradigm programming language is a programming language that supports more than one programming paradigm In other words a language that supports multi ple programming language styles A non Line of Sight radio transmiss
23. ecawave s EVK1000 evaluation boards During the work the most suitable technology meth ods and algorithms for sport tracking system were selected and the future indoor positioning system was designed This Bachelor s thesis can be used as a base line of the implementation of the ultra wideband based indoor positioning system Keywords Indoor positioning sport tracking ulta wideband Decawave CONTENTS ABSTRACT CONTENTS TERMS AND ABBREVIATIONS 1 INTRODUCTION 2 THEORY 2 1 Classification 2 2 Methods used in Indoor Positioning Systems 2 2 1 Time of Arrival TOA 2 2 2 Time Difference of Arrival TDOA 2 2 3 The Received Signal Strength Indicator RSSI 2 2 4 The Angle of Arrival AOA 2 3 Indoor Positioning Technologies 2 3 1 Non radio Technologies 2 3 2 Radio Signal Technologies 2 4 Design of wireless geolocation system 3 THE WORK ENVIRONMENT 3 1 Decawave DW1000 3 1 Bus Pirate v3 6 3 2 Ubuntu 14 10 3 3 Minicom 4 CONFIGURATION 5 TESTING 5 1 Hypothesis 5 2 The First Experiment 5 3 The Second Experiment 5 4 The Third Experiment 5 5 Results 6 CONCLUSION 7 REFERENCES 47 47 47 10 10 11 11 12 14 16 17 19 22 27 29 29 30 31 31 32 34 34 34 36 37 38 44 47 TERMS AND ABBREVIATIONS Anchor node Attenuation Bluetooth Fingerprinting GLONASS GPS Linux An anchor node is a party which communi cates via a radio signal with the target node and its location is known Also known as ref erenc
24. ences of multiple antenna components at the same receiver 8 However this method causes higher cost complexity and power consumption compared with other methods 3 a angle FIGURE 5 Estimation of the Angle of the Arriving Signal Between two Nodes 2 3 Indoor Positioning Technologies In the indoor positioning non radio technologies such as a magnetic positioning and inertial measurements can provide an increased accuracy and decrease the expenses of the system However these technologies are not suitable in all use cases Wireless technologies are the most used and developed technologies in the indoor positioning field 12 There are guite many radio signal technigue op tions for indoor positioning but all of them have their own advantages and disad vantages see figure 6 and figure 7 17 3 automation control etc lt guiding tracking routing etc as ai ad N 5 rad GSM CDMA 3G obile cellular network ane Proprietary TDOA 8 13 microwave F sd solutions RSS TDOA RTOF Indoors imeter 0 1meter 10meters wide Signal strength fihgepmt FIGURE 6 Accuracy of Different Positioning Systems in 2007 13 Technology Typical Typical Typical Accuracy Coverage m Measuring Principle Cameras 0 1mm dm 1 10 angle measurements from images Infrared cm m 1 5 thermal imaging active beacons Tactile amp Polar Systems im mm 3 200
25. he biggest measured deviation was 1 1 centimeters in 50 meters and the small est in 30 meters in where the deviation was nearly zero The first test measure ments in short distances demonstrate that the EWB1000 evaluation board might have been set to display a little lower value to measure a more accurate result in longer distances There are also some adverse factors which need to be taken into account when interpreting the results In longer distances there is a bigger probability to have a distraction on line of sight which affects on accuracy by ascending the value Additionally there is no evidence of having the tape measure placed exactly on a straight line Placing another EWB1000 board on highlighted points might also have caused a little offset because the board was placed on the points by hand 39 By EVB1000 measured average value compared with actual value 60 50 40 30 20 10 Actual value m 1 2 3 lt 5 6 7 Measurement point number measure EVB1000 FIGURE 29 Comparison Line Graph between Values Measured by the EVK1000 and Actual Values The results of the second experiment were dramatic but expected When the S1 2 switch of the EWB1000 evaluation board was turned to off it enabled the slow mode where the response time was 150 milliseconds In the experiment the range of transmission turned out to be 100 meters As the S1 2 switch was turned to on mode it enabled the high speed mode where the resp
26. ion across a path that is partially obstructed usually by a physical object The Open Source Initiative is a California public benefit corporation In brief they ap prove Open Source licenses Automatic identification technology which uses radio frequency electromagnetic fields to identify objects carrying tags when they come close to a reader SPI SPICS Target node Triangulation Trilateration Ultrasonic Unix A Serial Peripheral Interface is a hard ware firmware communications protocol de veloped by Motorola and later adopted by others in the industry The clock speed of the Serial Peripheral In terface A target node is another party which com municates with anchor nodes trying to find out its location Target node can be passive or active Also can be known as mobile ter minal located to a positioning target A method of finding a distance or location by measuring the distance between two points whose exact location is known and then measuring the angles between each point and a third unknown point A method of determining the relative posi tions of three or more points by treating these points as vertices of a triangle or tri angles of which the angles and sides can be measured Ultrasound is an oscillating sound pressure wave with a frequency greater than the up per limit of the human hearing range An operating system written in C program ming language developed in the 1970s UTF 8
27. ndently evolved bio sonar systems to navigate and locate and catch prey Toothed whales and bats are able to operate in darkness but also communicate with a same species comrade by ultrasonic 20 The freguency range of ultrasonic is from 20 kHz to 10 MHz Fig ure 10 The velocity of sound waves is about 340 m s whereas the speed of radio waves is 300 000 000 m s 15 Wavelength 100nm 1 um 10 100 um 1mm 10 mm 0 1m 1m 10m 100m 1 km audible Frequency 343 MHz 34 MHz 3MHz 343kHz 34 kHz 3 kHz 300 Hz 30H 3H 0 3 Hz FIGURE 10 The Black Line illustrates the Frequency Range of Ultrasonic 14 Slower velocity makes it a lot easier to estimate the time of flight measurement 15 Ultrasonic offers a low cost solution which can also be used in indoor posi tioning One of the disadvantages of an ultrasonic system is a loss of signal due to the interference with obstacles on line of sight Sometimes the signal can also turn to be false because of the reflection or measurement can face interference from other high frequency sounds such as keys jangling 12 Ultrasonic is also sensitive to temperature variations and multipath signals which makes it unsuita ble to some use cases 11 2 3 2 Radio Signal Technologies Radio signal technologies are the most developed technologies in indoor posi tioning field at the moment However the radio positioning systems are often more expensive compared to non radio based positioning systems 17
28. ntegrated antenna that gets its power from the received signals sent by anchor nodes In the RFID system the anchor nodes send signals with a specific freguency to keep the RFID tags activated as long as it is needed 3 Wavelength 100nm 1um 10 100 um 1mm 10mm 0 1m 1m 10m 100m 1km uv infrared i Frequency 3PHz 300THz 30 THz 3THz 300 GHz 30GHz 3GHz 300MH 30MHz 3MHz 300kHz FIGURE 15 The Black Line illustrates the Frequency Range of RFID 14 Electric Waves Radio Infra red UV Xray Gamma Ray Waves 9kHz 30kHz 300kHz 3000kHz 30 2 300MHz 3000MHz 3000 GHz VLF LF MF HF VHF UHF SHF EHF 5 8 GHz 125 kHz 13 56 MHz 2 45 GHz 134 2 kHz 433 and 860 960 MHz FIGURE 16 The Electromagnetic Spectrum with the Frequency Bands of the RFID Systems 26 2 4 Design of wireless geolocation system There are two kinds of ways to design a wireless geolocation system The first way is to implement a signaling system and a network infrastructure of location sensors focused on a geolocation application Figure 17 The advantage of the first case is to have the physical specification and guality of the location sensing results under control The mobile terminal can be designed as a wearable small tag or sticker which can be placed for example under a T shirt The density of the anchors of the system is in designer s hands so it can be changed easily if needed A Anchor node T Target node FIGURE17 Wireless Geolocation
29. on M Wahlberg M Surlykke A Madsen P T 2013 Ultrasonic preda tor prey interactions in water convergent evolution with insects and bats in air Frontiers in physiology Page 4 Frontiers in Physiology 21 Renaudin V Yalak O Tome P Merminod B 2007 Indoor navigation of emergency agents European Journal of Navigation 5 3 36 45 22 Home Bluetooth Technology Special Interest Group 2015 Date of re trieval 30 2 2015 https www bluetooth org en us 23 IEEE SA IEEE Get 803 Program 802 11 Wireless LANs 2015 Date of retrieval 1 3 2015 http standards ieee org about get 802 802 11 html 24 Lansford J Stephens A Nevo R 2001 Wi Fi 802 11 b and Bluetooth enabling coexistence Network IEEE 15 5 20 7 25 RFID freguency ranges 2015 Date of retrieval 2 3 2015 http www cen trenational rfid com rfid frequency ranges article 16 gb ruid 202 html 26 Decawave DW1000 user manual 2014 Date of retrieval 5 3 2015 http www decawave com sites default files resources dw1000 user man ual 2 03 pdf 27 Decawave EVK1000 user manual 2014 Date of retrieval 10 3 2015 http www decawave com sites default files product pdf evk1000 user man ual v107 pdf 28 Bus Pirate DP 2015 Date of retrieval 11 3 2015 http dangerousproto types com docs Bus Pirate 29 The leading OS for PC tablet phone and cloud Ubuntu 2015 Date of re trieval 12 3 2015 http www ubuntu com 30 Minicom
30. onse time was 5 milliseconds In the experiment the range of transmission turned out to be 22 meters which is too short for usage because the planned tracking area is about 60 meters long and 30 meters wide or even bigger TABLE 2 The Results of the Second Experiment Mode S1 2 switch Response time Range Slow speed off 150 ms 100 m High speed on 5 ms 22 m 40 The third experiment focused on the velocity issue when the device is in the high speed mode The video camera was used to gather the data during the drive In all trials when the target was in initial point it was in a rest state and started to accelerate to get the speed up to 20km h before passing the anchor node The first trial started in 100 meters away from the anchor node and the velocity of the target node was around 20km h when the target passed the an chor The device detected the target in 16 53 meters and lost the sight after 9 33 meters Table 3 In the second trial the target node started from 21 58 meters and did not reach 20km h before the anchor node The recording was stopped at 3 53 meters when the car was exactly aligned with the anchor node In both trial three and four the target node started at around 22 meters and it was recorded till the end Also in these two trials the velocity did not quite reach to 20km h In trial three the last distance in the end was 54 67 meters and in the trial four it was 66 25 meters The data gathered d
31. ow accurate the measurement per formed by two EWB1000 evaluation boards in different circumstances Is there a couple of factors which need be considered as adverse factors on the meas urement accuracy such as distance velocity temperature and objects placed on line of sight The adverse factors need to be taken into account because it is assumed that they have a strong effect on accuracy In this document just ve locity and distance issues were tested 5 1 Hypothesis According to the sources found about ultra wideband it is assumed that the UWB technology should not be suitable for a long distance measuring because of its limited transmission range of signals Therefore the measurement accuracy should decrease while lengthening the distance between two nodes It was also mentioned in one of the sources that the accuracy of the ultra wideband also decreases if there are any objects disturbing the line of sight of the radio signal Additionally it is assumed that velocity effects on descending range of ultra wide band signal 5 2 The First Experiment The first experiment was performed indoors using two EVK1000 boards two lap tops a tape measure a Shealt application on Galaxy S4 a pen and a paper During the first experiment the task was to evaluate the accuracy of the EWB1000 boards in indoor circumstances where the temperature varied from 8 C to 11 C and the humidity from 52 96 to 44 96 The main objective of the test was to mea
32. points which are related to its own loca tion points in the positioning area Those points can be static or dynamic Remote positioning systems are divided into two groups active and passive target remote positioning systems 3 Figure 1 Positioning systems Local positioning systems Global positioning systems L Self positioning systems Remote positioning systems Active target remote systems _ Passive target remote systems FIGURE 1 Classification of the Positioning Systems 10 2 2 Methods used in Indoor Positioning Systems By using radio signal technologies there are three location metrics used in the wireless indoor positioning to estimate the direction of the received signal or dis tance The angle of arrival AOA measures the arrival angle of the received sig nal in direction based systems In distance based systems the distance can be estimated by using the received signal strength RSS the carrier signal phase of arrival POA or the time of arrival TOA of the received signal 4 In order to obtain more accurate information about the position of the target node some po sitioning systems combine two or more position related parameters 5 The most commonly used techniques which can be used to determine the metrics are tri lateration triangulation and fingerprinting 6 The two major sources of errors in the location metrics in the indoor environment are no LOS NLOS
33. r a sport tracking indoor positioning system Different technologies methods and algorithms were explored and evaluated during the work This paper also gives a sight how to test and configure Decawave s EVK1000 evaluation board The main objective of this work was to discover a proper technology methods and algorithms for a sport tracking indoor positioning system and do an experimental evaluation for the selected device The evaluation of EVK1000 evaluation board was necessary for further develop ment 2 THEORY 2 1 Classification The need for indoor positioning is emerging but developers have not yet imple mented an enough accurate and suitable solution for all kinds of use cases 1 GPS and GLONASS are well known global positioning systems for outdoor envi ronments but there is not such a system for an indoor environment 2 Indoor positioning systems can be classified into two groups global and local positioning systems In the global positioning system GPS the mobile can find its own po sition on the globe The local positioning system LPS is a relative positioning system which can be classified into two subcategories called as a self and re mote positioning The self positioning system allows a target to find its position by using the static coordination points at any given time and location An example of self positioning systems is the inertial navigation system In remote positioning systems the system finds the reference
34. reference points can be located outside the building and therefore UWB is a more reliable technology than other radio signal technologies 1 Wavelength 100nm lum 10 um 100 um 1mm 10mm 0 1m im 10m 100m 1km UV Microwave Freguency 300THz 30 THz 3TH 300 GHz 30 GHz 3 GHz 300 MHz 30 MHz 3MHz 300kHz FIGURE 14 The Black Line illustrates the Frequency Range of UWB 14 In UWB based systems the reference points locate themselves using GPS and thus the tracked reference points can be converted to absolute coordinates The advantage of this system is that there is no need for pre installed infrastructure UWB is not suitable for large buildings because of a limited transmission range of signals Another disadvantage is that reference points need to be placed rela tively evenly around the building which makes the technique impractical or even impossible 1 25 2 3 2 4 RFID RFID is a wireless system that locates an object which has the RFID target node The RFID system consists of anchor nodes also called as reference points and target nodes 3 RFID operates at low freguencies 125 kHz 134 2 kHz high freguencies 13 56 MHz ultra high freguencies 860 MHz 960 MHz and super high freguencies 2 45 GHz 25 Figure 15 Figure 16 RFID systems can be classified into two groups such as passive remote systems and active remote systems according to whether they are using passive or active tags In passive RFID tags there is an i
35. rowave Radio Frequency 3PHz 300THz 30 THz 3 300 GHz 30GHz 30 3MHz 300kHz FIGURE 13 The Black Line illustrates the Freguency Range of WLAN 14 In emergency situations WLAN is often vulnerable because it reguires a local infrastructure However it has been used for indoor positioning in hospitals but for an accurate positioning the signal strength measurements and triangulation are not sufficient Advanced methods such as fingerprinting might be a solution but collecting a database of offline points is guite time consuming Nowadays 24 WLAN exists everywhere but most of them are not sufficient for accurate posi tioning The access points are not designed for positioning purposes and the den sity of points is too low to detect the different locations independently 1 Addi tionally the access points used in WLAN positioning systems are relatively ex pensive 21 2 3 2 3 UWB Ultra wideband is a slightly different radio technology which is also used in indoor positioning 1 The freguency range of UWB is from 3 1 GHz up to 10 6 GHz Figure 14 It has a large bandwidth gt 500 MHz which enables it to have a multipath communication UWB has a low transmit power compared with the amount of transmitted data The pulse duration varies between some picosec onds and nanoseconds 21 The low transmit power enables the pulses to not get affected by the interference with obstacles on line of sight The
36. seconds The slow speed mode was managed by turning the S1 2 switch to on state The S1 2 switch is used to en able fast two way ranging where the response time is set to 5 milliseconds If turned off the response time is set to 150 milliseconds Figure 26 After the first trial the EWB1000 boards were configured to a high speed mode where the response time was set to 5 milliseconds by turning the S1 2 switch to off state The temperature was around 0 C in the experiment environment 36 High speed mode 5 ms Slow speed mode 150 ms on 11213 4 5 678 jn 11213 4 5 FIGURE 26 S1 2 Pin enabled to change Time of Response 5 4 The Third Experiment During the third experiment the accuracy of the active target in outdoor circum stances was explored when the response time of the EWB1000 evaluation boards were increased This experiment was performed also outdoors using two EVK1000 boards two laptops a video camera a car a pen and a paper One of the EVK1000 boards was located as a static anchor node and other was placed as a dynamic tag into the car The objective of this experiment was to find out if it is enough to increase the response time from 150 milliseconds to 5 milliseconds to be able to track the active tag node when it has a high velocity Figure 27 20 km h N camera UWB signal anchor FIGURE 27 Tracking Active Tag in High Velocity 37 A video camera was used in this experiment to gather the data displa
37. sure how accurate the measurement is in a static state At first the tape measure was placed on a hallway and 2m 5m 10m 20m 30m 40m and 50m 34 points were highlighted One of the EWB1000 boards was placed in Om and an other was moved to the highlighted points step by step Figure 24 FIGURE 24 The Tape Measure was placed between two Nodes Every highlighted point was measured 5 times by the EWB1000 board and marked to a datasheet The EWB1000 interface displays AVG and AVG8 values however in this case only AVG8 was used The EWB1000 board which was placed on different points needed to be set carefully because even a little offset might have caused a bigger error value Figure 25 The EWB1000 boards were required to be connected to computers via a USB cable because they do not have their own power source 35 FIGURE 25 Measuring the Distance 5 3 The Second Experiment The second experiment was performed outdoors using two EVK1000 boards by turning the response time of the EVK1000 boards from a slow to a high speed The objective of this experiment was to find out how much the high speed mode decreases the range of transmission of the signal In the manual of the EVK1000 it is mentioned that when decreasing the response time from 150 mil liseconds to 5 milliseconds the range of line of sight decreases At first the EWB1000 evaluation boards were configured to be in a slow speed mode where the response time was 5 milli
38. tage of the TOA method is that there are already well developed timing based multiple access schemes which allow the high accurate TOA estimation The disadvantages of the TOA is that all the units need to be synchronized with each other in a system but synchronization is difficult and expensive to use for wireless radio systems 8 2 2 2 Time Difference of Arrival TDOA The time difference of arrival method is based on the measurement of the differ ence in time between the signals arriving at two anchors It is assumed that using this method the positions of the anchor nodes are known In the TDOA all anchor nodes receive the same signal transmitted by the target node 3 A perfect ex ample of a TDOA positioning system is the GPS The GPS satellites are synchro nized by means of using atomic clocks and monitoring through the ground control segment 8 Atomic clocks are extremely expensive so they are not quite suitable for indoor positioning systems One way to estimate the TDOA is to first estimate the TOA for each signal trans mitted between the target node and an anchor node and then to define the dif ference between the two estimated values Formula 2 5 TTDoA 2 FORMULA 2 The represents TDOA estimation and 12 the represents TOA value for the signal transmitted between the target node and the anchor node The TOA difference solution at the base nodes is a hyperbola In plane the dif ferenc
39. uring the third experiment shows that the data flow is not constant Table 3 Especially in the fourth trial the anchor lost the target after 16 25 meters and detected it again in 66 25 meters Comparing the first trial to others it can be considered that the anchor needs a pre response before start ing the tracking In the first trial the target node was placed far away from the anchor node and the anchor node did not detect it before start The target reached 20km h therefore it was not detected until in 16 53 meters The most accurate trial was the third one which does not include long intervals between the measurements TABLE 3 Recorded Data when the Target Node had Velocity of 20km h Trial 1th 100 m Trial 2nd 21 58 m Trial 3rd 22 29m Trial 4th 21 81m 16 53 m 21 58m 22 20 m 21 81m 13 74 m 19 62 m 22 28 m 20 08 m 11m 18 23 m 22 12 m 17 24 m 8 40 m 16 61 m 21 71 m 15 18 m 41 5 82 m 14 80 m 20 95 m 12 18 m 3 45m 10 72 m 15 66 m 10 14 m 1 49 m 8 40 m 12 00 m 7 46 m 2 24 m 5 99 m 9 87 m 4 65m 4 35m 3 53 7 60 1 87 6 75 5 23 1 59 9 33 2 78 4 43 1 01 7 56 2 76 10 37 5 36 13 30 8 07 16 28 10 82 66 25 13 67 16 24 18 61 20 81 23 11 34 90 37 34 39 69 41 95 44 20 46 30 48 27 49 91 42
40. yed on the screen of the EVK1000 evaluation board The data was valuable to evaluate how guickly the EVK1000 responds to a transmitted signal The video recording method was used because there was not yet a functionality in the system which would have stored the data to the server The video record was easy to evalu ate afterwards Figure 28 FIGURE 28 Experiment Eguipment of the Third Experiment 5 5 Results The first experiment was carried out as planned and the results gave more infor mation about the suitability of the EWB1000 evaluation board for further develop ment The results were recorded in one decimal place of accuracy The results of measurements of the first experiment were better than were expected Without any distraction on line of sight the measurements of EWB1000 boards were enough accurate As regarding to the Sparkline diagram the measurements where the distance was short between two nodes were descending compared with the actual values Table 1 When the distance was around 30 meters the measurement turned out to be exact As the distance was lengthened from 30 meters the results were ascending compared with the actual values 38 TABLE 1 The Results of Measurements by Decawave EWB1000 Device com pared to the Actual Values Although a Sparkline diagram shows a little deviation from the actual values the accuracy was proven to be enough accurate Figure 29 In the first experiment t
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