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1. Accuracy 2 0 rms Heading RGSS Oak Range Pitch 90 Attitude Roll 180 Accuracy 2 0 rms Resolution 0 01 Power Average Current Draw Maximum Sample Rate 55 mA Consumption Current Draw During Application of External Power See Figure 3 1 Table 3 2 Performance Specifications in Compass Mode Parameter METTE Static Accuracy 0 3 rms Heading Resolution 0 1 Repeatability 0 05 rms Range Pitch 90 Roll 180 Attitude Static Accuracy 0 2 rms Resolution 0 01 Repeatability 0 05 rms Power Average Current Draw Maximum Sample Rate 28 mA Consumption Sleep Mode Current Draw 0 5 mA Table 3 3 I O Characteristics Parameter Value Supply Voltage 3 6 to 5 VDC Communication Interface RS232 UART amp USB Communication Protocol PNI Binary Communication Rate 2400 to 921 600 baud Maximum Data Output Rate 30 samples sec PNI Sensor Corporation TRAX User Manual March 2012 DOC 1016505 r05 Page 3 of 60 Parameter Table 3 4 Environmental Requirements Parameter METT Operating Temperature 40C to 85C Storage Temperature 40C to 85C Table 3 5 Mechanical Characteristics Value Dimensions Trax Enclosed 6 4x5 9x2 3 cm 1x wx h Trax PCA 3 5 x 4 3 x 1 3 cm Trax Enclosed 75 gm at Trax PCA 7 gm Gonnadiar Trax Enclosed 7 pin ODU pn K20LOC PO7LCC0 520S Trax PCA 9 pin Molex pn 53780 0970 Footnotes to Tables
2. kTrueNorth Boolean True or False False kBigEndian 1 2 6 Boolean True or False True kMountingRef 10 Ulnt8 1 STD 0 2 XUP0 3 YUP0 4 STD 90 5 STD 180 6 STD 270 7 Z DOWN 0 8 X UP 90 9 X UP 180 10 X UP 270 li A UP SoS 12 Y UP 180 TEMUR 14 Z DOWN 90 15 Z DOWN 180 16 Z DOWN 270 kUserCalNumPoints 12 Ulnt32 4 18 12 kUserCalAutoSampling 13 Boolean True or False True kBaudRate 14 Ulnt8 4 2400 5 3600 6 4800 7 7200 8 9600 9 14400 10 19200 11 28800 12 38400 13 57600 14 115200 kMilOut 1S Boolean True or False False kHPRDuringCal 16 Boolean True or False True kMagCoeffCopySet 18 Ulnt32 ver kAccelCoeffCopySet 19 Ulnt32 0 7 Configuration parameters and settings for kSetConfig kDeclination Config ID 1d This sets the declination angle to determine True North heading Positive declination is easterly declination and negative is westerly declination This is not applied unless kTrueNorth is set to TRUE PNI Sensor Corporation TRAX User Manual March 2012 DOC 1016505 r05 Page 39 of 60 kTrueNorth Config ID 24 Flag to set compass heading output to true north heading by adding the declination angle to the magnetic north heading kBigEndian Config ID 6
3. Accelerometer Calibration Note The payload needs to be 32 bit 4 byte If no payload is entered or if less than 4 bytes are entered the unit will default to the previous calibration method PNI Sensor Corporation DOC 1016505 r05 TRAX User Manual March 2012 Page 47 of 60 The CalOption values are given below along with basic descriptions of the options Full Range Calibration Recommended calibration method when gt 45 of tilt is possible Can be used for between 20 and 45 of tilt but accuracy will not be as good 2D Calibration Recommended when the available tilt range is limited to lt 5 Can be used for 5 to 10 of tilt but accuracy will not be as good Hard Iron Only Calibration Recalibrates the hard iron offset for a prior calibration If the local field hard iron distortion has changed this calibration can bring the Trax back into specification Limited Tilt Range Calibration Recommended calibration method when gt 5 of tilt calibration is available but tilt is restricted to lt 45 i e full range calibration is not possible Accelerometer Calibration Select this when an accelerometer calibration will be performed Below is a complete sample packet to start a 2D Calibration kStartCal 00 09 00 00 00 14 5C F9 ByteCount Frame ID CalOption CalOption Checksum MSBs 2D Calibration Heading pitch and roll information is output via the kGetDataResp frame during the calibration process This fe
4. Single then only one measurement will be displayed on the screen The button will briefly gray out while the data is being output to the screen then return to reading lt Start gt TRAX User Manual r05 Page 28 of 60 Show 3D Model Selecting the lt Show gt button launches the 3D Model window as shown below Clicking the lt Start gt button begins continuous updating of the orientation of the rendered model and of the heading pitch and roll output fields The lt Start gt button on the Test Tab screen and on the 3D Model screen are linked such that selecting either of them will stop or start both screens Clicking on lt Fullscreen gt will expand the window to the full computer screen and the button will now read lt Windowed gt Clicking lt Windowed gt will shrink the window back down Output Format amp North Reference The Output Format and North Reference fields mimic the settings on the Configuration Tab To change these return to the Configuration Tab make the change then lt Apply gt or lt Save gt the change Background amp Foreground Color The foreground and background colors of the screen can be changed by the user Simply click on the color square and select the new desired color The change in color automatically is saved The default is black lettering on a grey background Functional Mode The Trax can operate either in AHRS Mode or Compass Mode While the Trax is intended to
5. To clear the data select lt Clear gt To clear both the data and the plot select lt Apply gt 6 9 System Log Tab The System Log tab shows all communication between Trax Studio and Trax Closing Trax Studio will erase the system log Select the lt Export gt button at the bottom right of the screen to save the system log to a text file Configuration Calibration Test Log Date Graph System Log 2011 11 17 09 29 37 Disconnected 2031 11 17 09 29 45 Connecting 2031 12 17 09 20 45 Connected 38400 bps 2058 38 97 09 29 45 Reading config 2011 41 47 09 29 46 Read config done F Atoso Ca Epet Denotes settings changed but nat yet applied Defaut ao TRAX User Manual r05 Page 32 of 60 7 Operation with PNI Binary Protocol The Trax utilizes PNI s binary protocol that is transmitted over either a USB virtual communication port or an RS232 UART Communication parameters should be set as follows Table 7 1 Communication Port Configuration Parameter Value Number of Data Bits 8 Start Bits 1 Stop Bits 1 Parity none 7 1 Datagram Structure The data structure is shown below ByteCount Packet Frame CRC 16 Ulnt16 1 4092 Ulnt8 Ulnt16 je e Payload Uints 1 4091 UlInt8 Figure 7 1 Datagram Structure The ByteCount is the total number of bytes in the packet including the CRC 16 checksum The CRC 16 is calculated starting from the ByteCount to the
6. User Manual FieldForce TRAX Attitude amp Heading Reference System AHRS INT SENSOR CORPORATION Table of Contents 1 COPYRIGHT amp WARRANTY INFORMATION ssssscccccccsssssseeceeceessssesceeees 1 2 INRODUCION 42545454 2 3 SPECIFICATIONS sis csssussixneessnsansnesnesanccsensncancpeusassarivcseusaiseriniaenieuperanceeni me 3 3 1 Characteristics amp Requirements rrrrrnrrnnnnnnnnrnrrenrrnsnnnnnnnnnrnnvnnrsnsnnnnnnnnnn 3 3 2 Mechanical Drawings ccscccscccccecesssesessaececeeeeessessaeeeeeeseseessesssaeess 5 2 SETUP E ET ETT EEEE 7 4 1 Electrical Comnechons uuuemuvsentmbmmsmnnjjenmnkenumnie 7 4 2 Installation LOCATION scctecsfecscodaagts sadesnus docdeguaadieiddacecediendacedonidesdmnatataancalucay 8 4 2 1 Operate within the Trax s dynamic range rannrnnnrannrrvnrsnnrvrnvssennnn 8 4 2 2 Locate away from changing magnetic fields rrrrrrnnrrrrrennrrvnnrne 8 4 2 3 Mount in a physically stable location srrrrrannrrrnvrrennrnvnrennrrvnrenn 8 4 3 Mechanical Mounting rrnnnnrorronrrronnnonnnnrrnrrnnnrnsnnnnnnnnrnnvnnssnsnnnnnnnnvsnnsnnr 8 4 3 1 Pitch and F lComenlbhuuvvaqvesummmimenmsn jeien 8 4 3 2 Mounting Orientation a ararnrnrnrnrnrnrnrnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnner 9 5 CALIBRATION REE 11 5 1 Magne tic CalibiatlOn aasisiasiancxesduiocsasauiesacauamcsaatvnlestdl vues vicaadtaahavmdavadias 12 5 1 1 Full Range Callbr tion uassnassemmmmmeaasnselmsaiens ea 13 5
7. lt 2 for other methods Note that it is possible to get acceptable scores for DistributionError and TiltError and still have a rather high MagCalScore value The most likely reason for this is the Trax is close to a source of local magnetic distortion that is not fixed with respect to the device Bytes 5 8 Reserved for PNI use AccelCalScore Represents the over riding indicator of the quality of the accelerometer calibration An acceptable score is lt 1 DistributionError Indicates if the distribution of sample points is good with an emphasis on the heading distribution The score should be 0 Significant clumping or a lack of sample points in a particular section can result in a poor score TiltError Indicates if the Trax experienced sufficient tilt during the calibration taking into account the calibration method The score should be 0 TiltRange This reports the larger of either half the full pitch range or half the full roll range of sample points For example if the device is pitched 10 to 20 and rolled 25 to 15 the TiltRange value would be 20 as derived from 25 15 2 For Full Range Calibration and Hard Iron Only Calibration this should be gt 45 For 2D Calibration ideally this should be 2 For Limited Tilt Range Calibration the value should be as large a possible given the user s constraints TRAX User Manual r05 Page 50 of 60 7 6 4 Factory Calibration kSetFactoryMagCoeff fram
8. kDistortion Component ID 84 This flag indicates at least one magnetometer axis reading is beyond 125 uT It is only applicable in Compass Mode and will always read FALSE in AHRS Mode kCalStatus Component ID 94 This flag indicates the user calibration status False means it is not user calibrated and this is the default value kAccelX kAccelY amp kAccelZ Component IDs 214 224 234 These values represent the accelerometer sensor data for the x y and z axis respectively The values are normalized to g Earth s gravitational force kMagX kMagY amp kMagZ Component IDs 274 284 294 These values represent the magnetic sensor data for the x y and z axis respectively The values are given in uT kGyroxX kGyroY kGyroZ Component IDs 744 754 764 These values represent the gyroscope sensor data for rotation around the x y and Z axis respectively The values are in radians per second 7 5 4 Making a Measurement kGetData frame ID 44 If the Trax is configured to operate in Polled Acquisition Mode see kSetAcqParams then this frame requests a single measurement data set The frame has no payload kStartContinuousMode frame ID 21 4 If the Trax is configured to operate in Continuous Acquisition Mode see kSetAcqParams then this frame initiates the outputting of data at a relatively fixed data rate where the data rate is established by the SampleDelay parameter The frame has no payload kStopContinuou
9. 07 9724971069144e 3 01 4823725958818e 3 2 04 5329134234467e 1 06 4500864832660e 2 01 2710056429342e 2 02 0737124095482e 3 3 04 5329134234467e 1 01 6637325898141e 1 02 5971390034516e 2 03 2757326624196e 3 4 04 6708657655334e 2 02 4925036373620e 1 04 6451949792704e 2 05 3097803863757e 3 5 02 4925036373620e 1 07 1024151197772e 2 08 3414139286254e 3 6 01 6637325898141e 1 09 5354386848804e 2 01 2456836057785e 2 7 06 4500864832660e 2 01 1484431942626e 1 01 7646051430536e 2 8 01 9875512449729e 2 01 2567124916369e 1 02 3794805168613e 2 9 01 2567124916369e 1 03 0686505921968e 2 10 01 1484431942626e 1 03 8014333463472e 2 11 09 5354386848804e 2 04 5402682509802e 2 12 07 1024151197772e 2 05 2436112653103e 2 13 04 6451949792704e 2 05 8693165018301e 2 14 02 5971390034516e 2 06 3781858267530e 2 15 01 2710056429342e 2 06 7373451424187e 2 16 07 9724971069144e 3 06 9231186101853e 2 17 06 9231186101853e 2 18 06 7373451424187e 2 19 06 3781858267530e 2 20 05 8693165018301e 2 21 05 2436112653103e 2 22 04 5402682509802e 2 23 03 8014333463472e 2 24 03 0686505921968e 2 25 02 3794805168613e 2 26 01 7646051430536e 2 27 01 2456836057785e 2 28 08 3414139286254e 3 29 05 3097803863757e 3 30 03 2757326624196e 3 31 02 0737124095482e 3 32 01 4823725958818e 3 DOC 1016505 r05 Page 53 of 60 PNI Sensor Corporation TRAX User Manual March 2012 kSetFIRFiltersDone frame ID 20 4 This frame is the response
10. 330 lt 45 30 to 40 Footnote 1 Yaw listings are not absolute heading directions but rather relative heading referenced to the first sample 5 1 2 2D Calibration A 2D Calibration is intended for very low tilt operation lt 5 where calibrating the Trax with greater tilt is not practical This procedure calibrates for hard and soft iron effects in only two dimensions and in general is effective for operation and calibration in the tilt range of 5 to 5 The recommended 12 point calibration pattern is a circle of evenly spaced points as given in Table 5 3 PNI Sensor Corporation DOC 1016505 r05 TRAX User Manual March 2012 Page 15 of 60 Footnote Table 5 3 12 Point 2D Calibration Pattern Sample Yaw Pitch Roll 1 0 0 0 2 30 max negative max negative 3 60 0 0 4 90 max positive max positive 5 120 0 0 6 150 max negative max negative 7 180 0 0 8 210 max positive max positive 9 240 0 0 10 270 max negative max negative 11 300 0 0 12 330 max positive max positive 1 For best results the tilt experienced during calibration should match that experienced in service For example if the Trax is restrained to a level plane in service then calibration should be in a plane where max positive and max negative are 0 5 1 3 Limited Tilt Range Calibration A Limited Tilt Range
11. Calibration is recommended when 45 of tilt isn t feasible but gt 5 of tilt is possible It provides both hard iron and soft iron distortion correction The recommended 12 point calibration pattern given below is a series of 3 circles of evenly spaced points with as much tilt variation as expected during use Table 5 4 12 Point Limited Tilt Calibration Pattern Sample Yaw Pitch Roll First Circle 1 0 0 0 2 90 0 0 3 180 0 0 6 270 0 0 Second Circle 7 45 gt 5 gt 5 8 135 gt 5 gt 5 11 225 gt 5 gt 5 12 315 gt 5 gt 5 Third Circle 13 45 lt 5 lt 5 14 135 lt 5 lt 5 17 225 lt 5 lt 5 18 315 lt 5 lt 5 TRAX User Manual r05 Page 16 of 60 Note that a similar and acceptable alternative pattern would be to follow the recommended 12 point Full Range Calibration pattern but substituting the gt 45 of pitch with whatever pitch can be achieved and the 10 to 20 of roll with whatever roll can be achieved up to these limits See Section 5 1 1 for more information 5 1 4 Hard Iron Only Calibration It is not uncommon for the hard iron magnetic distortions around the Trax to change Some reasons for this include significant temperature change or temperature shock to a system as well as gradual aging of components A Hard Iron Only Calibration allow
12. FALSE or 1 TRUE 7 0 byte 7 3 Commands Overview Table 7 2 provides a summary of the basic commands available with the Trax These commands are discussed in the following subsections Table 7 2 Trax Binary Command Set de Command Description Set Up 1 kGetModInfo Queries the device s type and firmware revision 2 kGetModInfoResp Response to kGetModInfo 6 kSeiConfig Sets internal configurations in Trax 19 kSetConfigDone Response to kSetConfig 7 kGetConfig Queries Trax for the current internal configuration 8 kGetConfigResp Response to kGetConfig Sets if dip angle amp radius establish mag truth ee ge dre Badalona criteria tight 120 kGetMagTruthMethod Queries for standard or tight truth method 121 kGetMagTruthMethodResp Response to kGetMagTruthMethod 9 ke Saves the current internal configuration and any new user calibration coefficients to non volatile memory 16 kSaveDone Response to kSave Operation 110 kSetResetRef Establishes criteria for the reference magnetic field 24 kSetAcqParams Sets the sensor acquisition parameters 26 kSetAcqParamsDone Response to kSetAcqParams 25 kGetAcqParams Queries for the sensor acquisition parameters 27 kGetAcgParamsResp Response to kGetAcqParams 3 kSetDataComponents Sets the data components to be output 4 kGetData Queries the Trax for data 5 kGetDataResp Response to kGetData 21 kStartContinuousMode Comm
13. User Manual March 2012 Page 13 of 60 The recommended 12 point calibration pattern is a series of 3 circles of evenly spaced points as illustrated in Figure 5 1 and listed in Table 5 2 The pitch used in the second and third circles of the calibration should at least match the maximum and minimum pitch the device is expected to encounter in use Minimum 12 good user calibration points Additional points can be added including upside down if possible Alternate Roll between points odd number points positive roll even negative roll Side Views Top Views ca 1 Large Positive j Pitch R AA 11 Pitch Figure 5 1 12 Point Full Range Calibration Note While Figure 5 1 shows the location of the device changing this is for illustration purposes and it is best for the location of the device to remain constant while only the orientation is changed TRAX User Manual r05 Page 14 of 60 Table 5 2 12 Point Full Range Calibration Pattern Sample Yaw Pitch Roll First Circle 1 0 50 30 to 40 2 90 5 30 to 40 3 180 5 30 to 40 4 270 59 30 to 40 Second Circle 5 30 gt 45 30 to 40 6 120 gt 45 30 to 40 7 210 gt 45 30 to 40 8 300 gt 45 30 to 40 Third Circle 9 60 lt 45 30 to 40 10 150 lt 45 30 to 40 11 240 lt 45 30 to 40 12
14. an extended period 6 12 months typically If either of these Reset buttons are selected it is necessary to click lt Save gt or lt Apply gt to have the factory coefficients take effect PNI Sensor Corporation DOC 1016505 r05 TRAX User Manual March 2012 Page 27 of 60 6 6 Test Tab The Test Tab is used to demonstrate and evaluate the performance of the Trax The Heading Pitch and Roll are output during testing as well as the Heading Status The Heading Status provides an indication of the accuracy of the heading A green box represents a heading accuracy of lt 2 a yellow box means the heading uncertainty is approximately 2 to 10 and a red box means the uncertainty is gt 10 These heading uncertainties assume the Trax was properly calibrated in a clean magnetic environment Configuration Calibration Te Log Data Graph System Log Test Output Vest Settings sv re EE Son 3D Model Output Format DEGREES Morth Reference MAGNETIC sigordco Dente stings hang a yet ape C Start Stop Testing Clicking the lt Start gt button results in the Heading Pitch and Roll values being updated on the Test Tab screen as well as the Heading Status If the Acquisition Mode is set to Continuous then the data will be continuously updated The button will change to read lt Stop gt such that clicking it again will stop the screen from updating If the Acquisition Mode is set to
15. in the Trax are calibrated at PNI s factory in a magnetically controlled environment However sources of magnetic distortion positioned near the Trax in the user s system will distort Earth s magnetic field and should be compensated for in the host system with a user calibration Examples of such sources include ferrous metals and alloys ex iron nickel steel etc batteries audio speakers current carrying wires and electric motors Compensation is accomplished by mounting the Trax in the host system and performing a user calibration It is expected the sources of magnetic distortion remain fixed relative to the Trax s position within the host system By performing a calibration the Trax identifies the local sources of magnetic distortion and negates their effects from the overall reading to provide an accurate heading As with the magnetic sensors the accelerometers in the Trax are calibrated at PNI s factory But the accelerometers gradually change over time and the user either will need to periodically perform a user accelerometer calibration or return the unit to PNI for recalibration As a rule of thumb the accelerometers should be recalibrated every 6 to 12 months Unlike a magnetic calibration the accelerometers may be calibrated outside the host system Accelerometer calibration is more sensitive to noise or hand jitter than magnetic calibration especially for subsequent use at high tilt angles Because of this a stabilized
16. on Figure 3 2 After making the electrical connections it is a good idea to perform some simple tests to ensure the Trax is working as expected See Section 6 for how to operate the Trax with Trax Studio or Section 7 for how to operate the Trax using PNI s binary protocol PNI Sensor Corporation DOC 1016505 r05 TRAX User Manual March 2012 Page 7 of 60 4 2 Installation Location The Trax s wide dynamic range and sophisticated algorithms allow it to operate in many environments For optimal performance however you should mount the Trax with the following considerations in mind 4 2 1 Operate within the Trax s dynamic range The Trax can be field calibrated to correct for static magnetic fields created by the host system However each axis of the Trax has a calibrated dynamic range of 125 uT If the total field exceeds this value for any axis the Trax may not perform to specification When mounting the Trax consider the effect of any sources of magnetic fields in the host environment that when added to Earth s field may take the Trax out of its dynamic range For example large masses of ferrous metals such as transformers and vehicle chassis large electric currents permanent magnets such as electric motors and so on 4 2 2 Locate away from changing magnetic fields While the Trax can compensate for transient changes in the local magnetic field it is good design practice to keep the Trax away from sources of local magneti
17. then do so Note that the module must be motionless when being plugged in and for 5 seconds afterwards as this is when the gyros initialize Double click on the Trax Studio icon to launch Trax Studio Below is a picture of the Trax Studio header The header includes Module Information and Connection Settings and PNI Sensor Corporation DOC 1016505 r05 TRAX User Manual March 2012 Page 19 of 60 under the header are the various Trax Studio tabs which are discussed in the subsequent sections The header is the same regardless of which tab is selected dd MAAS 10 99 0 Fie Edt Hep Mode Deformation Tanneching Sattings Type TRAX SM 10316680 Sana Dort coms E Stabs Connected amp 32400 bps Rev P727 PCARevi ROS Baud Rate 400s Configuration Calibration Test Graph Data Log System Log To connect set the Serial field to the appropriate COM port To determine this in Windows right click on My Computer select Manage then select Device Manager Expand Ports and note the port for USB Serial Port This should be the assigned COM port for the Trax Set the baud rate The default is 38400 and this should be the setting the first time the Trax is used Once a connection has been established the desired baud rate can be changed on the Configuration Tab as discussed in Section 6 4 1 Click the lt Connect gt button When the connection is established the light
18. to the left of Status will turn green Status will change to Connected the baud rate the lt Connect gt button will now say lt Disconnect gt the lt Power Down gt button will be live and the Device Information section of the header will populate 6 3 Trax Studio Footer and Saving Applying Settings Below is a picture of the Trax Studio footer The footer includes 4 buttons which are discussed below The footer is the same regardless of which tab is selected Note that if a field is changed on any of the Trax Studio tabs then either lt Apply gt or lt Save gt must be selected for the change to take effect Denotes settings changed but nat yet applied Read Swe TRAX User Manual r05 Page 20 of 60 Save Clicking the lt Save gt button will save any changes made in Trax Studio to the Trax s onboard non volatile and volatile memory Apply Selecting the lt Apply gt button will apply any changes to the Trax s volatile memory but not to the non volatile memory If the Trax is powered off on the settings will revert to whatever was last saved in the non volatile memory Read Clicking the lt Read gt button will read the current settings in the Trax s volatile memory and display them This will change any item in bold which indicates a setting was changed in Trax Studio but not applied to the Trax s volatile memory back to regular type and the setting change will not be applied to the
19. 1 2 DAA DAG 15 5 1 3 Limited Tilt Range Calibration rrrrrnnnnnrorrnnrrnnnnnnnnnnnrnrvnnennnnnn 16 5 1 4 Hard Iron Only Calibration sororrrnnrnononnnnrnrvnnennrsnnnnnnnnrnvvnnsnnnnnn 17 5 2 Accelerometer Calibration rsnrrvnnannnnvnnenennnvnnneennrvenssnnnnvnsessnnrsesse 17 6 GETTING STARTED WITH TRAX STUDIO cccccccsssssseeceecccesssssceeceeeeeeees 19 6 1 nstallati Mennin aar nacciedantaceaniadlalestwanas 19 6 2 Trax Studio Header and Connecting to Trax Studi ccseeeeeseees 19 6 3 Trax Studio Footer and Saving Applying SettingS ccccscccsseeeees 20 6 4 Configuration TAD eeiszcctsyeiied daceeecessveved ccvevdecsssevextacseteees a KE 21 6 4 1 General Settings sa csacancnesaciiuisnriect ania be eae 22 6 4 2 ACQUISITION Settings r rrrrrvrvrvrvvvrvevenarevaverarevanenanenanananenanannnen 23 6 5 Calibration and the Calibration Tab uarenvrnrnrennrrvrrennnrrnnesverrrnvsrennn 24 6 5 1 Calibration Settings nersinioseei ean aa 24 6 5 2 Performing a Calibration ccccccccccccsssssessessececeeeesssssssseaeeeeees 26 6 5 3 Calibration RESUltSnnricorinneniancnneinne aR 26 6 6 Test TaD ninne E a 28 6 7 Eor ADEI E EE E A E A 30 6 8 Graph Ta Disses srne a E A a 31 6 9 System Log TD Ladies 32 PNI Sensor Corporation DOC 1016505 r05 TRAX User Manual March 2012 Page i 7 OPERATION WITH PNI BINARY PROTOCOL esernenevrennnevvnnnnnvvnnnnnenennnuneeennnee 33 7 1
20. 4 Sets the Endianness of packets TRUE is Big Endian FALSE is Little Endian kMountingRef Config ID 104 This sets the reference orientation for the Trax Please refer to Figure 4 2 for additional information kUserCalNumPoints Config ID 124 The user must select the number of points to take during a calibration The number of sample points must be within the listed Allowable Range or the Trax may not work properly Calibration generally is not as good if less than the Minimum Recommended is selected but may be acceptable Table 7 4 Sample Points Number of Samples Calibration Mode Allowable Recommended Range Pattern Full Range Calibration 10 to 18 12 Limited Tilt Calibration 10 to 18 12 2D Calibration 10to 18 12 Hard Iron Only 4 to 18 6 Accelerometer 18 18 kUserCalAutoSampling Config ID 134 This flag is used during user calibration If set to TRUE the Trax automatically takes calibration sample points once the minimum change and stability requirements are met If set to FALSE the device waits for kTakeUserCalSample to take a sample with the condition that a magnetic field vector component delta is greater than 5 uT from the last sample point If the user wants to have maximum control over when the calibration sample point are taken then this flag should be set to FALSE kBaudRate Config ID 144 Baud rate index value A power down power up cycle is required when changing the baud
21. ARON temperature varies Current MA 300 250 Specifications are typical unless otherwise noted and subject to change Assumes heading status is 1 See Section 6 6 or Section 7 5 3 Assumes Trax is motionless and the local magnetic field is clean relative to user calibration The Trax can operate up to 921 600 baud but native RS232 is limited to 115 200 baud To meet performance specifications across this range recalibration will be necessary as the Time ms Figure 3 1 Typical Current Drawing During Application of External Power TRAX User Manual r05 Page 4 of 60 3 2 Mechanical Drawings DIMENSIONS ARE MILLIMETERS 35 000 0 051 702870 990 29 00040 025 CLEARANCE FOR Va 4 40 UNC FASTENER hv QS 43 000 37 00040 025 2X 3 00020 025 x 5 LZ 2X 3 00040 025 MOLEX PIN 53780 0970 Figure 3 2 Trax PCA Mechanical Drawing L 457 6 18 00 0 25 gt il 76 5 Molex PN 51146 0900 er ar ee dimensions in mm inches Figure 3 3 PNI Pigtailed Molex Cable Drawing PNI Sensor Corporation DOC 1016505 r05 TRAX User Manual March 2012 Page 5 of 60 inches 14 825 i s mm 376213 Dimensions In 12 52 5 318213 i CONNECTOR ODU P N K20L0C POTLCC0 5605 TNT Figure 3 4 Trax Enclosed Mechanical Drawing _ EE FR O MESH Figure 3 5 Trax USB Cable Drawing vERMOLDET re Figure 3 6 Trax RS232 Cable Drawing TRAX Use
22. Datagram Structure r ranannrnnrrnrnnenanennrnnsnnrnnnnnnsnssnnvnvsnnnnnnenessrnnrnnnnnnese 33 7 2 Parameter FORMAtS wisseeviaietenssiereniassceistanevene neta E REA 34 7 3 Commands OVerviemLu umommetupnmeentimibuvnidatpdnevndde 36 7 4 Set Up CommandS ij sisrctsncidaingcsdacosancaudesedesdageantaleapasdetaseudaeeialiadiuagaved 37 7 4 1 Module Inf rmatlbhVosasgnmsgumnaenmmmauvn 37 7 4 2 Module Configuration rrrnnrororrrnrrnannnnnnnnnrrnvrnrrnnnnnnnnrnnsnnssnsnnn 38 7 4 3 SAVING Settingsuuuuuaanduumigtnitdavvitandvimetikedv 42 7 5 Measurement Commandsuvuvrvveamdns adardamnsaandddsndinn 43 7 5 1 Setting the Reference Magnetic Field Criteria rrrnnannnnrnnerennr 43 7 5 2 Data Acquisition Parameters rnnnnnnnnnnnnnnnnnnnnnnnnvnnnenenennnnnenener 43 7 5 3 Data COMPONENTS 2 045 ss ede eieledassevlae Nadie ena aaliedee 44 7 5 4 Making a M aSureMme nt c ccsccccccceceesesssseseeesececeeessseseseseeees 46 7 6 Calibration Commands vuuaasaasasammmmmenuimvelhjv 47 7 6 1 User Calibration CommandS ssrvrnrannrnvnnannnnvnnsernnnrnnnssnnrvvnssnnnnene 47 7 6 2 Performing a User Calibration cccccccssssseceesssseeeecessseeeeeesenes 49 7 6 3 Calibration SCONG uasorrardeneeda jada 50 7 6 4 Factory Calibration disencsicceaniasiannaicaseradsanaeiiwaienierecenacies 51 7 7 Compass Mode Commands csessssececeeeceseesseseaeeecececessessnseaeeeeees 51 7 7 1 Switching Functional Mode rasennvnnneennvnvneennvrnnsssnnnnvnssn
23. Section 5 To perform a calibration follow the following steps e Click the lt Start gt button to begin the calibration process e If Automatic Sampling is not checked the first sample will be taken automatically assuming the Trax is relatively stationary After this it is necessary to click the lt Take Sample gt button to take a calibration sample point This should be repeated until the total number of samples is taken changing the orientation of the device between samples as discussed in Section 5 1 e If Automatic Sampling is checked the Trax needs to be held steady for a short time and then a sample automatically will be taken Once the window indicates the next number the device s orientation should be changed and held steady for the next sample Once the pre set number of samples has been taken as set on the Configuration tab the calibration is complete Regardless of whether Automatic Sampling is selected two criteria must be met for a calibration sample to be taken First the Trax must be held steady enough to meet PNI defined stability criteria Second the Trax s orientation must have changed enough to meet PNI defined orientation change criteria If H P R Output During Cal is selected then the Heading Pitch and Roll fields will be populated in real time once the lt Start gt button is selected Note that the readings in these fields are relative since calibration is in proces
24. Trax s memory Default Selecting the lt Default gt button will display the default settings which are stored in Trax Studio Selecting this button will not automatically apply these values and either lt Apply gt or lt Save gt must be selected for the read values to be applied 6 4 Configuration Tab The Configuration Tab is shown below and its contents discussed in the following subsections For any changes to take effect the lt Save gt button must be selected Clicking on the lt Default gt button will load the factory default values although these must be saved to take effect Clicking the lt Retrieve gt button will show the current settings of the device organ Celestion Test LogDete Gah Syste Log are al Settings Atkotian Setting Raat Rate 4H had Aquisition Mode Conbinucus av Mounting Stoo hd Sancie Delay s 5 00 Output Units Degrees E North Reference Magnetic fa Fish Fiber Decidon 000 Fiter Taps 32 bd Denotes settings changed but not yet applied bet d Reed Apply Seve PNI Sensor Corporation DOC 1016505 r05 TRAX User Manual March 2012 Page 21 of 60 6 4 1 General Settings Baud Rate The baud rate can be altered by selecting the desired baud rate from the pull down menu clicking on Save and then powering the device off and back on The new baud rate will not take effect until the device has been powered off on The default baud rate is 38400 Mounting Trax Studio supports 16
25. Trax Studio makes this request at a fixed rate which is set by the Polling Delay In both cases data is continuously output but in Continuous Acquisition Mode the Trax controls the data rate while in Polled Mode the Trax Studio program controls the data rate Polled Mode is the default Sample Delay The Sample Delay is relevant when Continuous Mode is selected It is the time delay in seconds between completion of Trax sending one set of data and the start of sending the next sample set If the delay is set to 0 then Trax will begin sending new data as soon as the previous data set has been sent Note that the inverse of the Sample Delay is greater than the sample rate since the Sample Delay does not include the actual measurement acquisition time The default is 0 Polling Delay The Polling Delay is relevant when Polled Mode is selected It represents the time delay in seconds between the completion of Trax Studio receiving one set of sampled data and requesting the next sample set If the delay is set to 0 then Trax Studio requests new data as soon as the previous request is fulfilled Note that the inverse of the Polling Delay is greater than the sample rate since the Polling Delay does not include the actual measurement acquisition time The default is 0 PNI Sensor Corporation DOC 1016505 r05 TRAX User Manual March 2012 Page 23 of 60 6 5 Calibration and the Calibration Tab As discussed in Section 5 a user calibration shoul
26. User Manual r05 Page 54 of 60
27. ands the Trax to output data at a fixed interval 22 kStopContinuousMode Stops data output when in Continuous Mode TRAX User Manual r05 Page 36 of 60 Calibration 10 kStartCal Commands the Trax to start user calibration 11 kStopCal Commands the Trax to stop user calibration Commands the Trax to take a sample during user 31 kTakeUserCalSample calibration 17 kUserCalSampleCount ae from the Trax after taking a calibration sample 18 kUserCalScore Contains the calibration score Resets magnetometer calibration coefficients to se PESO eG Eol original factory established values 30 kSetFactoryMagCoeffDone Response to kSetFactoryMagCoeff Resets accelerometer calibration coefficients to oe reacio ninteke oo original factory established values 37 kSetFactoryAccelCoeffDone Respond to kSetFactoryAccelCoeff Compass Mode 79 kSetFunctionalMode Puts Trax in Compass Mode or AHRS Mode 80 kGetFunctionalMode Queries for Compass Mode or AHRS Mode 81 kGetFunctionalModeResp Response to kGetFunctionalMode Sets the FIR filter settings for the magnetometer amp ie KEM SEE accelerometer sensors 20 kSetFIRFiltersDone Response to kSetFIRFilters Queries for the FIR filter settings for the magnetometer ue SECIS amp accelerometer sensors Contains the FIR filter settings for the magnetometer amp 1 KOMPANIENE accelerometer sensors 15 kPowerDown Powers down the module 28 kPowe
28. ane As shown in Figure 4 1 for the Trax a positive pitch is when the front edge of the board is rotated upward and a positive roll is when the right edge of the board is rotated downward The order of rotation is given as heading pitch and then roll Vs RAVEL ad ar lt 5 eS t p gt el Ne 4 Q CA y P gt as we a x Se NEGA V 4 Di 2 7 SS p r Wiad VETT IVE Ha i lt T en aiie MOL ain NEGATIV Figure 4 1 Positive amp Negative Roll and Pitch Definition 4 3 2 Mounting Orientation The Trax can be mounted in 16 different orientations as shown for the enclosed version of the Trax in Figure 4 2 All reference points are based on the silk screened arrow on the cover of the enclosed version of the Trax or on top side of the Trax PCA board The orientation should be programmed in the Trax using the Configuration Tab in Trax Studio or using the kSetConfig command and the kMountingRef setting in the PNI Protocol as described in Section 7 4 2 The default orientation is STD 0 PNI Sensor Corporation DOC 1016505 r05 TRAX User Manual March 2012 Page 9 of 60 x UP o Figure 4 2 Trax Enclosed Mounting Orientations TRAX User Manual r05 Page 10 of 60 5 Calibration To optimize the performance of the Trax such that it performs to specification it is necessary to properly calibrate both the magnetic sensors and the accelerometers in the device The magnetic sensors
29. ature provides guidance during the calibration regarding calibration sample point coverage During calibration in the kGetDataResp frame the number of data components is set to be 3 and then followed by the data component ID value pairs The sequence of the component IDs are kHeading kPitch and kRoll kTakeUserCalSample frame ID 31 4 This frame commands the Trax to take a sample during user calibration The frame has no payload TRAX User Manual r05 Page 48 of 60 kUserCalSampleCount frame ID 17 4 This frame is sent from the Trax after taking a calibration sample point The payload contains the sample count with the range of to 18 Payload SampleCount Ulnt32 kStopCal frame ID 114 This command aborts the calibration process The prior calibration results are retained 7 6 2 Performing a User calibration The steps below provide an example of the steps to perform a user calibration Using the kSetParam command set the number of tap filters to 0 Using the kSetConfig command set kUserCalAutoSampling False is generally recommended but True may be more convenient Using the kSetConfig command set kCoeffCopySet magnetometer calibration and or kAccelCoeffCopySet accelerometer calibration These fields allow the user to save multiple sets of calibration coefficients 0 is the default Using the kSetConfig command again set kUserCalNumPoints to the appropriate number of calibration poi
30. available but tilt is restricted to lt 45 i e full range calibration is not possible Accelerometer The user should select this when accelerometer calibration will be performed Accelerometer calibration is recommended every 6 to 12 months to Page 24 of 60 compensate for bias drift in the accelerometer The Trax can also be returned to PNI for accelerometer calibration Number of Points This establishes how many samples will be taken during the calibration The minimum and recommended number of samples depends on the calibration method and is summarized in Table 5 1 The maximum number of samples is 18 Mag Coefficient Set amp Accel Coefficient Set At any one time the Trax will use one set of magnetic calibration coefficients and one set of accelerometer calibration coefficients The magnetic coefficients compensate for measured magnetic distortions in the host system as determined during a magnetic calibration The accelerometer coefficients compensate for bias and offset of the accelerometers as determined during an accelerometer calibration However the Trax can store eight 8 sets of magnetic calibration coefficients and eight 8 sets of accelerometer calibration coefficients This feature is useful if the compass will be placed in multiple locations that have different local magnetic field properties The default is index number 0 and initially this is populated at PNI with factory generated coefficients for the dev
31. be used as an AHRS there are times when it is necessary or beneficial to PNI Sensor Corporation DOC 1016505 r05 TRAX User Manual March 2012 Page 29 of 60 place it in Compass Mode Specifically it is necessary to calibrate the Trax in Compass Mode This is handled automatically in Trax Studio so it is not necessary for the user to place the Trax in Compass Mode when doing a calibration in Trax Studio Also it may be beneficial to operate in Compass Mode to conserve battery life since in Compass Mode the Trax turns off the gyros generally uses less CPU power and can be placed in Sleep Mode to significantly reduce current consumption Truth Method This field allows the user to have control over the breadth of criteria used to establish if the local magnetic field conforms to the reference magnetic field criteria Auto is the default Reference Field Reset Clicking the Reference Field lt Reset gt button re establishes the criteria for a clean magnetic field After clicking this button the Heading Status box will go green Assuming an accurate heading reading is desired this should be done only when the user is confident the local magnetic field is free from distortions For the purpose of demonstrating the general capabilities of the Trax a distortion free local magnetic field may not be required but the user should realize the heading reading likely will not meet the accuracy specification 6 7 Log Data Tab Trax St
32. c distortion that knowingly will change with time such as electrical equipment that will be turned on and off or ferrous bodies that will move 4 2 3 Mount in a physically stable location Choose a location that is isolated from persistent vibration or other dynamic motion The Trax can provide accurate headings while experiencing intermittent dynamic motion such as vibration or quick heading changes But if this is persistent the Trax will have difficulty holding an accurate heading over extended periods of time 4 3 Mechanical Mounting The Trax is factory calibrated with respect to its mounting holes It must be aligned within the host system with respect to these mounting holes Ensure any stand offs or screws used to mount the Trax are non magnetic Refer to Section 3 2 for dimensions hole locations and the reference frame orientation 4 3 1 Pitch and Roll Convention The Trax utilizes Euler angles as the primary method for providing orientation data although quaternions outputs also are available The Euler angles are the common method used for aircraft orientation where the outputs are heading pitch and roll When TRAX User Manual r05 Page 8 of 60 using Euler angles in aviation roll is defined as the angle rotated around an axis through the center of the fuselage while pitch is rotation around an axis through the center of the wings These rotations are dependent on each other since the axes of rotation move with the pl
33. cal magnetic field then a somewhat higher level of accuracy is achievable in Compass Mode Also by placing the Trax in Compass Mode it can subsequently be placed into Sleep Mode which will significantly reduce power consumption when not taking measurements 7 7 1 Switching Functional Mode kSetFunctionalMode frame ID 79 4 This frame establishes whether the Trax operates in AHRS Mode or Compass Mode The frame has a one byte payload The payload byte is 0 to operate in Compass Mode and 1 to operate in AHRS Mode The default is 1 PNI Sensor Corporation DOC 1016505 r05 TRAX User Manual March 2012 Page 51 of 60 Payload FunctionalMode Payload Value FunctionalMode 0 Compass Mode 1 AHRS Mode default Ulnt8 Sending the kSave command after changing the mode will save the new setting in non volatile memory kGetFunctionalMode frame ID 80 4 This frame queries the Trax functional mode The frame has no payload kGetFunctionalModeResp frame ID 81 4 This is the response of kGetFunctionalMode and it has the same payload definition as kSetFunctionalMode 7 7 2 FIR Filters When operating in Compass Mode the Trax incorporates a finite impulse response FIR filter to provide a more stable heading reading The number of taps or samples represents the amount of filtering to be performed The number of taps directly affects the time for the initial sample reading as all the taps must be po
34. chnology papers Hard Iron Effects Hard iron distortions are caused by permanent magnets and magnetized steel or iron objects within close proximity to the sensors This type of distortion remains constant and in a fixed location relative to the sensors for all heading orientations Hard iron distortions add a constant magnitude field component along each axis of sensor output Soft Iron Effects Soft iron distortions are the result of interactions between the Earth s magnetic field and any magnetically soft material within close proximity to the sensors In technical terms soft materials have a high permeability The permeability of a given material is a measure of how well it serves as a path for magnetic lines of force relative to air which has an assigned permeability of one Unlike hard iron distortion soft iron distortion changes as the host system s orientation changes making it more difficult to compensate Temperature Effects While the hard iron and soft iron distortions of a given component in a system may remain quite stable over time normally this distortion signature will change over temperature Therefore no matter how stable a compass is over temperature it is usually necessary to recalibrate as the temperature changes since the magnetic distortion signature of the host system will change over temperature One way the Trax helps with this issue is by allowing the user to save up to 8 sets of calibration coeffic
35. d be performed to optimize Trax performance The Calibration Tab is shown below and following this are discussions of how to set the calibration settings how to perform a calibration and how to interpret the results 6 5 1 Configuration Calbration Test LogDate Graph System Log Cair ation Settings st akan Cale ation beste Type Full Range vi et Mag Cal Number of Points 2 Accel Cat Mag Coslticnnt Set 6 vi Cestrbution Error Accel Cosfficent Set 0 5 Ta Error 9 Automatic Samberg Ti Range Burr Output During Cal C Audible Feedback Mag Factory Reset Accel Factory Reset Reset oser ret Je Je Denotes settings Changed but not yet applied Calibration Settings Calibration Type TRAX User Manual r05 The Calibration Type pull down menu establishes the type of calibration to be performed The options are Full 2D Hard Iron Only Limited Tilt Range and Accelerometer These are briefly discussed below and in more detail in Section 5 Full Range recommended calibration method when gt 45 of tilt is possible 2D recommended when the available tilt range is limited to lt 5 Hard Iron Only serves as a hard iron recalibration to a prior calibration If the hard iron distortion around the device changes this procedure can bring the device back into specification more quickly than other methods Limited Tilt Range recommended calibration method when gt 5 of tilt calibration is
36. d be selected when the host system will poll the Trax for each data set Continuous Mode should be selected if the user will have the Trax output data to the host system at a relatively fixed rate FlushFilter This is only relevant in Compass Mode Setting this flag to TRUE results in the FIR filter being flushed cleared after every measurement The default is FALSE Flushing the filter clears all tap values thus purging old data This can be useful if a significant change in heading has occurred since the last reading as the old heading data would be in the filter Once the taps are cleared it is necessary to fully repopulate the filter before data is output For example if 32 FIR taps is set PNI Sensor Corporation DOC 1016505 r05 TRAX User Manual March 2012 Page 43 of 60 32 new samples must be taken before a reading will be output The length of the delay before outputting data is directly correlated to the number of FIR taps PNiReserved These 4 bytes serve no function PNI recommends populating the bytes with 0 SampleDelay The SampleDelay is relevant when the Continuous Acquisition Mode is selected It is the time delay in seconds between completion of Trax sending one set of data and the start of sending the next data set The default is 0 seconds which means Trax will send new data as soon as the previous data set has been sent Note that the inverse of the SampleDelay is somewhat greater than the actual sample rate
37. dges taking one calibration sample on each edge Then place the Trax flat on the surface and take a calibration sample then flip it over roll it 180 and take another sample Next starting with the Trax as shown on the right take a calibration point with it being vertical 0 Now tilt the Trax back 45 and take another calibration point 45 then tilt the device forward 45 and take another calibration point 45 Repeat this 3 point calibration process for the Trax with it resting on each of its 4 corners Note that it is possible to perform an Accelerometer Calibration with as few as 12 sample points although it generally is more difficult to obtain a good calibration with just 12 sample points Also the maximum number of calibration points is 18 Figure 5 2 Accelerometer Calibration Starting Orientations TRAX User Manual r05 Page 18 of 60 6 Getting Started with Trax Studio The Trax Studio program puts an easy to use graphical user interface GUI onto the binary command language used by the Trax Trax Studio is intended for evaluating demonstrating and calibrating the enclosed version of Trax Trax Enclosed Among other features the program can log and save the outputs from the Trax to a file for off line evaluation Anything that can be done using Trax Studio also can be done using PNI s binary protocol as discussed in Section 7 6 1 Installation Trax Studio is provided as an executable program which ca
38. e ID 29 4 This frame clears the magnetometer calibration coefficients and loads the original factory generated coefficients The frame has no payload This frame must be followed by the kSave frame to save the change in non volatile memory kSetFactoryMagCoeffDone frame ID 30 4 This frame is the response to kFactoryMagCoeff frame The frame has no payload kSetFactoryAccelCoeff frame ID 36 4 This frame clears the accelerometer calibration coefficients and loads the original factory generated coefficients The frame has no payload This frame must be followed by the kSave frame to save the change in non volatile memory kSetFactoryAccelCoeffDone frame ID 37 4 This frame is the response to kFactory AccelCoeff frame The frame has no payload 7 7 Compass Mode Commands The Trax normally operates in AHRS Mode which uses a proprietary Kalman algorithm to fuse the inputs of its 3 axis gyroscope 3 axis accelerometer and 3 axis magnetometer However the user can place the Trax in Compass Mode wherein it only uses the inputs from the accelerometer and magnetometer to establish heading pitch and roll In this case the Trax operates very similarly to PNI s TCM electronic compass There are a couple of reasons it may be desirable to place the Trax in Compass Mode As previously mentioned it is necessary to place the Trax in Compass Mode to perform a calibration Additionally if a static measurement is to be made in a known clean lo
39. electing a larger number of taps can significantly slow the time for the initial sample reading and if Flush Filters is selected the rate at which data is output The default setting is 32 TRAX User Manual r05 Page 22 of 60 The FIR filtering operates on a first in first out FIFO basis For example with FIR Taps set to 32 once the initial 32 samples are taken the next sample 33 is included in the filtering and the initial sample 1 is dropped from the filtering Flush Filter The Flush Filter setting is only relevant when in Compass Mode as it affects how the FIR filters are implemented Flushing the FIR filter clears all the filter values so it is necessary to fully repopulate the filter before a good reading can be given For example if 32 FIR taps is set then 32 new samples must be taken to provide a good reading It is particularly prudent to flush the filter if the Sampling Delay is set to a non zero value as this will purge old data Note that flushing the filters increases the delay until data is output with the length of the delay being directly correlated to the number of FIR taps The default is not to Flush Filters 6 4 2 Acquisition Settings Acquisition Mode When operating in Continuous Acquisition Mode the Trax continuously outputs data to the host system The rate is set by the Sample Delay When operating in Polled Mode Trax Studio simulates a host system and polls the Trax for a single measurement but
40. ennvnsseennr 51 7 7 2 FIR FFF 52 7 7 3 Power Down Up gane vers cunartsncoetianionearniuearasadacaaninaeeaateeceeass 54 List of Figures Figure 3 1 Typical Current Drawing During Application of External Power 4 Figure 3 2 Trax PCA Mechanical Drawing ccccsssscsceceeeeeeseessaeeeeeeeeseessssseaeees 5 Figure 3 3 PNI Pigtailed Molex Cable Drawing sccccssssececesssneeceesssseeeesesnneeens 5 Figure 3 4 Trax Enclosed Mechanical Drawing essrrrnvnronnvrvrrennrvenessrernrnssrennrvensene 6 Figure 3 5 Trax USB Cable Drawing suizeciigcd eccascataendages crcdhvadaconssidesengehedacsannddaaaguadduns 6 Figure 3 6 Trax R5232 Cable Drawing siicssssuccasevsatacuevaucievasrane st seadoauevevens silecdenstvacnts 6 Figure 4 1 Positive amp Negative Roll and Pitch Definition rrororrrnrrnonnnnnnrnrsnnnnrr 9 Figure 4 2 Trax Enclosed Mounting Orientations ccccccccsssseceeessnteeeeesseeeees 10 Figure 5 1 12 Point Full Range Calibration rrnnrorrrrrrnonnnnnnnnnnnrvnnennrnnnnnnnnrnnsnne 14 Figure 5 2 Accelerometer Calibration Starting Orientations rrnrrrrrrnnvrvnnnn 18 Figure 7 1 Datagram Structure rerrnononrnrnrnrnrnrnrnrnrnrnsnrnsnsnsnsnsnsnsnsnsnsnsnsnsnrnrnenen 33 TRAX User Manual r05 Page ii List of Tables Table 3 1 Performance Specifications in AHRS MOde ssccccesssseeceesesteeeeeees 3 Table 3 2 Performance Specifications in Compass Mode cccece
41. fixture is suggested for accelerometer calibration although resting the unit against a stable surface often is sufficient Key Points e User calibration is required for the Trax to perform optimally and meet specification e Magnetometer calibration o Requires incorporating the Trax into the user s host system such that the magnetic components of the user s system can be compensated for o Allows for 4 different methods of calibration Full Range Calibration provides the highest heading accuracy but requires 245 of pitch during calibration 2D and Limited Tilt Calibration allow for good calibration when the range of allowable motion is limited Hard Iron Only Calibration updates the hard iron compensation coefficients with a relatively easy procedure e Accelerometer calibration requires rotating the Trax through a full sphere of coverage but the Trax does not need to be incorporated into the user s system during calibration PNI Sensor Corporation DOC 1016505 r05 TRAX User Manual March 2012 Page 11 of 60 5 1 Magnetic Calibration Two fundamental types of magnetic distortion exist hard iron and soft iron These are discussed in the following paragraphs plus a discussion on how temperature effects magnetic fields and other considerations For more information on magnetic distortion and calibration see PNI s white paper Local Magnetic Distortion Effects on 3 Axis Compassing at PNI s website http www pnicorp com te
42. ice itself The other sets initially are unpopulated To store a coefficient set first select the index number 0 to 7 then perform a calibration The coefficient values will be stored in the defined index number assuming the lt Save gt is selected after the calibration To recall and use a different set of coefficients change the Mag Coefficient Set and or Accel Coefficient Set number then click the lt Save gt button Automatic Sampling If selected the Trax will take a sample point once predefined minimum change and stability requirements have been satisfied If the user wants to have more control over when the point will be taken then Auto Sampling should be deselected H P R Output During Cal When selected the heading pitch and roll of the device will be output below the sample number during a calibration Using this feature the user can monitor the device s orientation to easily follow the appropriate recommended calibration pattern Since a calibration is being performed these values are relative and should not be considered accurate Audible Feedback If selected Trax Studio will give an audible signal when a calibration sample is taken PNI Sensor Corporation DOC 1016505 r05 TRAX User Manual March 2012 Page 25 of 60 6 5 2 Performing a Calibration Before proceeding ensure you are familiar with the recommended calibration pattern corresponding to the Type selected These are discussed in
43. ients so that as the temperature changes a magnetic calibration coefficient set matching the new temperature can be used in the Trax Other Considerations The Trax measures the total magnetic field within its vicinity and this is a combination of Earth s magnetic field and local magnetic sources The Trax can compensate for local static magnetic sources However a magnetic source which is not static such as a motor which turns on off can create errors and it is not possible to compensate for such a dynamic nature In such cases keeping the Trax away from dynamic magnetic fields is recommended or taking measurements only when the TRAX User Manual r05 Page 12 of 60 state of the magnetic field is know For example only take measurements when a nearby motor is turned off The main objective of a magnetic user calibration is to compensate for hard iron and soft iron distortions to the magnetic field caused by components within the user s host system To that end the Trax needs to be mounted within the host system and the entire host system needs to be moved as a single unit during a user calibration The Trax allows the user to perform a calibration only in a 2D plane or with limited tilt but provides the greatest accuracy if the user can rotate through a full sphere The following subsections provide instructions for performing a magnetic calibration of a Trax system Calibration may be performed using Trax Studio or using the PNI bina
44. kTemperature 7 Float32 Celsius kDistortion 8 Boolean Ea kCalStatus 9 Boolean oan kAccelX 21 Float32 G kAccelY 22 Float32 G kAccelZ 23 Float32 G kMagX 27 Float32 ul kMagY 28 Float32 uT kMagZ 29 Float32 ul kGyrox 74 Float32 radians sec kGyroY 75 Float32 radians sec kGyroZ 76 Float32 radians sec Component types are listed below All are read only values kHeading kPitch kRoll Component IDs 54 244 254 Provides compass heading pitch and roll outputs The heading range is 0 0 to 359 9 the pitch range is 90 0 to 90 0 and the roll range is to 180 0 to 180 0 kHeadingStatus Component IDs 794 The heading status provides an indication of the uncertainty of the heading 1 represents a heading uncertainty of lt 2 2 means the heading uncertainty is approximately 2 to 10 and 3 means the uncertainty is gt 10 Quaternion Component ID 774 The quaternion values generated by the Trax algorithm are output in one data package that contains the four quaternions The quaternions are output as QO QI PNI Sensor Corporation DOC 1016505 r05 TRAX User Manual March 2012 Page 45 of 60 Q2 and Q3 where Q3 is the scalar quaternion When in AHRS Mode heading pitch and roll are subsequently calculated from these quaternions kTemperature Component ID 74 This value is provided by the device s internal temperature sensor Its value is in degrees Celsius and has an accuracy of 3 C
45. last byte of the Packet Frame The ByteCount and CRC 16 are always transmitted in big Endian Two examples follow Example The complete packet for the kGetModInfo command which has no payload is ByteCount Frame ID Checksum Example Below is a complete sample packet to start a 2D Calibration kStartCal 00 09 00 00 00 14 5C F9 ByteCount Frame ID CalOption CalOption Checksum MSBs 2D Calibration PNI Sensor Corporation DOC 1016505 r05 TRAX User Manual March 2012 Page 33 of 60 7 2 Parameter Formats Note Floating point based parameters conform to ANSI IEEE Std 754 1985 Please refer to the Standard for more information PNI also recommends the user refer to the compiler s instructions to understand how the compiler implements floating point format 64 Bit Floating Point Float64 Below is the 64 bit float format in big Endian In little Endian the bytes are in reverse order in 4 byte groups eg big Endian ABCD EFGH little Endian DCBA HGFE 63 62 5251 0 S Exponent Mantissa The value v is determined as v 1 S 2 Exponent 1023 1 Mantissa if and only if 0 lt Exponent lt 2047 32 Bit Floating Point Float32 Shown below is the 32 bit float format in big Endian In little Endian format the 4 bytes are in reverse order LSB first 3130 2322 0 S Exponent Mantissa The value v is determined as v 1 S 2 Exponent 127 1 Mantissa if and only if 0 l
46. mounting orientations as previously illustrated in Figure 4 2 The default is Standard Output Units The Trax can output heading pitch and roll in either degrees or mils The default is Degrees There are 6400 mils in a circle such that 1 degree 17 7778 mils and 1 mil 0 05625 degree North Reference When Magnetic is selected the heading output will be relative to magnetic north When True is selected heading will be relative to true north and the declination value should be entered in the next field The default is Magnetic Declination The declination represents the heading difference between magnetic north and true north and needs to be entered if True is selected as the North Reference Declination varies primarily with location although it also gradually changes over time years for a given location To find the declination for where the Trax will be used go to http www ngdc noaa gov geomagmodels Declination jsp Filter Taps When operating the Trax in Compass Mode the Trax will use a finite impulse response FIR filter to effectively provide a stable heading reading When operating in AHRS Mode a completely different filtering method is used and the number of FIR Taps is not relevant The number of taps or samples represents the amount of filtering to be performed Either 0 4 8 16 or 32 taps may be selected with zero taps representing no filtering Note that s
47. n be downloaded from PNI s website It will work with Windows XP Windows Vista and Windows 7 operating systems Check the PNI web page at www pnicorp com for the latest version Copy the TraxStudio msi file onto your computer Double click on the icon and step through the Setup Wizard The program will be installed into the following directory unless you direct it otherwise Program Files PNI Sensor Corporation TRAX Studio A Trax Studio shortcut icon will be placed on your computer s desktop Now plug the Trax into the USB port of your computer Ensure the Trax is completely still when plugging it into the USB port as the gyros initialize during the first five seconds after being plugged in If you are using the Windows XP operating system then the first time you plug in the Trax device it will launch the Found New Hardware Wizard Select a Yes button then click on lt Next gt and proceed with the installation The computer should find the required virtual communications port VCP driver by searching the internet which may take a minute or two If you are using Windows 7 the computer automatically searches for and installs the driver If there is a problem with this download the driver from FTDI s website at http www ftdichip com Drivers VCP htm You have now completed the installation of Trax Studio 6 2 Trax Studio Header and Connecting to Trax Studio If the Trax is not already plugged into the computer
48. nfig frame ID 74 This frame queries the Trax for the current internal configuration value The payload contains the configuration ID requested Payload Config ID Ulnt8 kGetConfigResp frame ID 84 The response to kGetConfig is given below The payload contains the configuration ID and value Payload Ulnt8 ID Specific Example If a request to get the set declination angle the payload would look like PNI Sensor Corporation DOC 1016505 r05 TRAX User Manual March 2012 Page 41 of 60 Payload Declination ID Declination Angle Float32 kSetMagTruthMethod frame ID 1194 This frame allows the user to have control over the breadth of criteria used to establish if the local magnetic field conforms to the reference magnetic field criteria The AutoMerge criteria is the default The payload is defined below Payload MagTruthMethod Payload Value MagTruthMethod 1 Standard 2 Tight Ulnt8 3 AutoMerae kGetMagTruthMethod frame ID 120 4 This frame queries the setting of the Mag Truth Method It has no payload kGetMagTruthMethodResp frame ID 121 4 This frame is the response of kGetMagTruthMethod and the payload is the same as for kSetMagTruthMethod 7 4 3 Saving Settings kSave frame ID 94 This frame commands the Trax to save internal configurations and user calibration to non volatile memory Internal configurations and user calibration are restored on power up The frame has n
49. nts Initiate a calibration using the kStartCal command Note that this command requires indentifying the type of calibration procedure i e Full Range 2D etc Follow the appropriate calibration procedure as discussed in Section 5 If kUserCalAutoSampling was set to False then send a kTakeUserCalSample command when ready to take a calibration point If kUserCalAutoSampling was set to True then look for kUserCalSampCount to confirm when a calibration point has been taken During the calibration process heading pitch and roll information will be output from the Trax and this can be monitored using kDataResp When the final calibration point is taken the device will present the calibration score using kUserCalScore If the calibration is acceptable see Section 7 6 2 save the calibration coefficients using kSave PNI Sensor Corporation DOC 1016505 r05 TRAX User Manual March 2012 Page 49 of 60 7 6 3 Calibration Score kUserCalScore frame ID 18 4 The calibration score is automatically sent upon taking the final calibration point The payload is defined below and the various payload components are discussed after this Payload MagCalScore Bytes 5 8 AccelCalScore DistributionError TiltError TiltRange Float32 Float32 Float32 Float32 Float32 Float32 MagCalScore Represents the over riding indicator of the quality of the magnetometer calibration Acceptable scores will be lt 1 for full range calibration
50. o payload This is the ONLY command that causes the device to save information to non volatile memory kSaveDone frame ID 16 4 This frame is the response to kSave frame The payload contains a UInt16 error code 0 indicates no error 1 indicates an error when attempting to save data to memory Payload Ulnt16 TRAX User Manual r05 Page 42 of 60 7 5 Measurement Commands 7 5 1 Setting the Reference Magnetic Field Criteria Prior to operating the Trax in AHRS mode it is necessary to establish the criteria for a known distortion free local field This should be done with the Trax installed in the host system as the distortion presented by the host system is constant and will be compensated for by the Trax algorithms kSetResetRef frame ID 110 4 This frame re aligns the Trax 9 axis heading to the 6 axis mag and accel heading and establishes the criteria for the reference magnetic field The frame should be sent when the user is confident the local magnetic field is not distorted It has no payload 7 5 2 Data Acquisition Parameters kSetAcqParams frame ID 24 4 This frame sets the sensor acquisition parameters in the Trax The payload should contain the following Payload AcquisitionMode FlushFilter PNIReserved SampleDelay Ulnt8 Ulnt8 Float32 Float32 AcquisitionMode This flag sets whether output will be presented in Continuous or Polled Acquisition Mode Continuous Mode is TRUE and is the default Polled Mode shoul
51. pulated before data is output The FIR filter settings have no affect when operating in AHRS Mode The Trax can be configured to clear or flush the filters after each measurement as discussed in Section 7 5 2 Flushing the filter clears all tap values thus purging old data This can be useful if a significant change in heading has occurred since the last reading as the old heading data would be in the filter Once the taps are cleared it is necessary to fully repopulate the filter before data is output For example if 32 FIR taps is set 32 new samples must be taken before a reading will be output The length of the delay before outputting data is directly correlated to the number of FIR taps kSetFIRFilters frame ID 124 The payload for kSetFIRFilters is given below Payload Ulnts Ulnt8 Ulnt8 ID Specific ID Specific ID Specific ID Specific Byte 1 should be set to 3 and Byte 2 should be set to 1 The third payload byte indicates the number of FIR taps to use which can be 0 no filtering 4 8 16 or 32 This is followed by the tap values 0 to 32 total Values can be in the payload with each Value being a Float64 and suggested values given in Table 7 6 TRAX User Manual r05 Page 52 of 60 Table 7 6 Recommended FIR Filter Tap Values Count 4 Tap Filter 8 Tap Filter 16 Tap Filter 32 Tap Filter 1 04 6708657655334e 2 01 9875512449729e 2
52. r Manual r05 Page 6 of 60 4 Set Up This section describes how to configure the Trax in your host system To install the Trax into your system follow these steps e Make electrical connections to the Trax e Evaluate the Trax using the Trax Studio program or a binary terminal emulation program such as RealTerm or Tera Term to ensure the Trax is working properly e Choose a mounting location e Mechanically mount the Trax in the host system e Perform a user calibration 4 1 Electrical Connections The enclosed version of Trax incorporates a pigtailed 7 pin ODU connector part number K20L0C PO7LCCO0 560S which mates with ODU part S20LOC TO7MCCO0 560S_ or equivalent The Trax PCA incorporates a 9 pin Molex connector part number 53780 0970 which mates with Molex part 51146 0900 or equivalent The pin out for both is given below in Table 4 1 Table 4 1 Trax Pin Descriptions Trax Enclosed Trax PCA Pigtailed 7 Pin 9 Pin Molex PNI Cable Connector Connector Wire Color 1 USB D Ground Black 2 RS232 5 VDC USB 5 VDC Gray 3 RS232 Tx Ground Green 4 RS232 Rx Not Connected Orange 5 USB 5 VDC USB D Violet 6 USB D A USB D Brown 7 Ground RS232 Tx Yellow 8 RS232 Rx Blue 9 RS232 5 VDC Red Footnote 1 For the Trax Enclosed pin 1 is the first pin to the left of the key and numbering runs counter clockwise from pin 1 with pin 7 in the middle For the Trax PCA pin 1 is indicated
53. rDownDone Response to kPowerDown 23 kPowerUpDone Confirms the Trax has received a signal to power up 7 4 Set Up Commands 7 4 1 kGetModinfo frame ID 14 Module Information This frame queries the device s type and firmware revision number The frame has no payload kGetModinfoResp frame ID 24 The response to kGetModInfo is given below The payload contains the device type identifier followed by the firmware revision number Payload Ulnt32 PNI Sensor Corporation TRAX User Manual March 2012 Ulnt32 DOC 1016505 r05 Page 37 of 60 Note that the Type and Revision can be decoded from the binary format to character format using the ASCII standard For example the hex string 00 OD 02 54 52 41 58 31 32 30 38 C7 87 can be decoded to read Trax 1208 7 4 2 Module Configuration kSetConfig frame ID 64 This frame sets internal configurations in the Trax The first byte of the payload is the configuration ID followed by a format specific value These configurations can only be set one at time To save these in non volatile memory the kSave command must be issued Payload Ulnt8 ID Specific Example To configure the declination the payload would look like Payload Declination ID Declination Angle Float32 TRAX User Manual r05 Page 38 of 60 Settings kDeclination Table 7 3 Configuration Identifiers Config ID4 Format Values Range Float32 180 to 180 Default 0
54. rate kMilOut Config ID 154 Sets the output units as mils TRUE or degrees FALSE The default is FALSE TRAX User Manual r05 Page 40 of 60 kHPRDuringCal Config ID 164 This flag sets whether or not heading pitch and roll data are output simultaneously while the Trax is being calibrated The default is TRUE such that heading pitch and roll are output during calibration FALSE disables simultaneous output kMagCoeffCopySet Config ID 184 This command provides the flexibility to store up to eight 8 sets of magnetometer calibration coefficients in the Trax The default is set number 0 To store a set of coefficients first establish the set number number 0 to 7 using kMagCoeffCopySet then perform the magnetometer calibration The coefficient values will be stored in the defined set number This feature is useful if the compass will be placed in multiple locations that have different local magnetic field properties kAccelCoeffCopySet Config ID 194 This command provides the flexibility to store up to eight 8 sets of accelerometer calibration coefficients in the Trax The default is set number 0 To store a set of coefficients first establish the set number number 0 to 7 using kAccelCoeffCopySet then perform the accelerometer calibration The coefficient values will be stored in the defined set number kSetConfigDone frame ID 19 q This frame is the response to kSetConfig frame The frame has no payload kGetCo
55. ritten notice to the OEM however PNI may at any time without such notice make minor changes to specifications or manufacturing processes that do not affect the form fit or function of the Product This warranty will be void if the Products serial number or other identification marks have been defaced damaged or removed This warranty does not cover wear and tear due to normal use or damage to the Product as the result of improper usage neglect of care alteration accident or unauthorized repair THE ABOVE WARRANTY IS IN LIEU OF ANY OTHER WARRANTY WHETHER EXPRESS IMPLIED OR STATUTORY INCLUDING BUT NOT LIMITED TO ANY WARRANTY OF MERCHANTABILITY FITNESS FOR ANY PARTICULAR PURPOSE OR ANY WARRANTY OTHERWISE ARISING OUT OF ANY PROPOSAL SPECIFICATION OR SAMPLE PNI NEITHER ASSUMES NOR AUTHORIZES ANY PERSON TO ASSUME FOR IT ANY OTHER LIABILITY If any Product furnished hereunder fails to conform to the above warranty OEM s sole and exclusive remedy and PNI s sole and exclusive liability will be at PNI s option to repair replace or credit OEM s account with an amount equal to the price paid for any such Product which fails during the applicable warranty period provided that i OEM promptly notifies PNI in writing that such Product is defective and furnishes an explanation of the deficiency 11 such Product is returned to PNI s service facility at OEM s risk and expense and iii PNI is satisfied that claimed deficiencie
56. ry protocol and up to 8 sets of calibration coefficients may be saved The recommended calibration patterns described in the following sub sections provide a good distribution of sample points Also PNI recommends the location of the Trax remain fairly constant while only the orientation is changed Table 5 1 Magnetic Calibration Mode Summary ofSamplesin Allowable Recommended Range of Calibration Static Accuracy in Tilt Range Mode Compass Mode during Cal Cal Pattern of Samples Full Range 0 3 rms gt 45 12 10 18 2D Calibration lt 2 lt 15 12 10 18 Limited Tilt 5 o 10 18 Range lt 2 over 2x tilt range 5 to 45 12 Hard Iron Only Restores prior 343 6 4 18 accuracy Before proceeding with a calibration ensure the Trax is properly installed in the host system The device should be installed as discussed in Section 4 and the software should be properly configured with respect to the mounting orientation Endianness north reference etc Section 6 5 outlines how to perform a calibration using Trax Studio while Section 7 6 2 provides a step by step example of how to perform a calibration using the PNI protocol 5 1 1 Full Range Calibration A Full Range Calibration is appropriate when the Trax can be tilted 45 or more This method compensates for hard and soft iron effects in three dimensions and allows for the highest accuracy readings PNI Sensor Corporation DOC 1016505 r05 TRAX
57. s 6 5 3 Calibration Results Once the calibration is complete the Calibration Results section will indicate the quality of the calibration This may take a few seconds to populate The primary score of concern is the MagCalScore or AccelCalScore depending on whether a magnetic or accelerometer calibration was performed The other parameters provide information that may assist in improving the MagCalScore should it be unacceptably high If a calibration is acceptable then click the lt Save gt button to save the calibration coefficients to the coefficient set defined on the Configuration Tab Note If a calibration is aborted all the score s will read 179 80 and the calibration coefficients will not be changed Clicking the lt Save gt button will not change the calibration coefficients TRAX User Manual r05 Page 26 of 60 Mag Cal Represents the over riding indicator of the quality of a magnetic calibration Acceptable scores are lt 1 for Full Range Calibration and lt 2 for other methods Note that it is possible to obtain acceptable Distribution Error and Tilt Error scores and still have a rather high Mag Cal value The most likely reason for this is the Trax is close to a source of magnetic distortion that is not fixed with respect to the device Accel Cal Represents the quality of an Accelerometer Calibration The score should be lt 1 Distribution Error Indicates if the distribution of sample points is good
58. s 45 Table 7 6 Recommended FIR Filter Tap Values cccsssscccesssteceessssteeeessseneees 53 PNI Sensor Corporation DOC 1016505 r05 TRAX User Manual March 2012 Page iii of 60 1 Copyright amp Warranty Information Copyright PNI Sensor Corporation 2011 All Rights Reserved Reproduction adaptation or translation without prior written permission is prohibited except as allowed under copyright laws Revised March 2012 For most recent version visit our website at www pnicorp com PNI Sensor Corporation 133 Aviation Blvd Suite 101 Santa Rosa CA 95403 USA Tel 707 566 2260 Fax 707 566 2261 Warranty and Limitation of Liability PNI Sensor Corporation PNI manufactures its Trax products Products from parts and components that are new or equivalent to new in performance PNI warrants that each Product to be delivered hereunder if properly used will for one year following the date of shipment unless a different warranty time period for such Product is specified 1 in PNI s Price List in effect at time of order acceptance or ii on PNI s web site www pnicorp com at time of order acceptance be free from defects in material and workmanship and will operate in accordance with PNI s published specifications and documentation for the Product in effect at time of order PNI will make no changes to the specifications or manufacturing processes that affect form fit or function of the Product without w
59. s exist and were not caused by accident misuse neglect alteration repair improper installation or improper testing If a Product is defective transportation charges for the return of the Product to OEM within the United States and Canada will be paid by PNI For all other locations the warranty excludes all costs of shipping customs clearance and other related charges PNI will have a reasonable time to make repairs or to replace the Product or to credit OEM s account PNI warrants any such repaired or replacement Product to be free from defects in material and workmanship on the same terms as the Product originally purchased Except for the breach of warranty remedies set forth herein or for personal injury PNI shall have no liability for any indirect or speculative damages including but not limited to consequential incidental punitive and special damages relating to the use of or inability to use this Product whether arising out of contract negligence tort or under any warranty theory or for infringement of any other party s intellectual property rights irrespective of whether PNI had advance notice of the possibility of any such damages including but not limited to loss of use revenue or profit In no event shall PNI s total liability for all claims regarding a Product exceed the price paid for the Product PNI neither assumes nor authorizes any person to assume for it any other liabilities Some states and provinces do no
60. s for quick recalibration of the Trax for hard iron effects and generally is effective for operation and calibration in the tilt range of 3 or more 245 is preferred The recommended 6 point calibration pattern given below is a circle of alternately tilted evenly spaced points with as much tilt as expected during use Table 5 5 6 Point Hard Iron Only Calibration Pattern Sample Yaw Pitch Roll 1 0 max negative max negative 2 60 max positive max positive 3 120 max negative max negative 4 180 max positive max positive 5 240 max negative max negative 6 300 max positive max positive Footnote 1 For best results the tilt experienced during calibration should match that experienced in service For example if the Trax will be subject to 45 of pitch and roll when in service then max negative should be 45 and max positive should be 45 5 2 Accelerometer Calibration The Trax uses MEMS accelerometers to measure the attitude pitch and roll of the compass This data is output as pitch and roll data Additionally the accelerometer data is critical for establishing an accurate heading reading when the Trax is tilted as discussed in the PNI white paper Tilt Induced Heading Error in a 2 Axis Compass which can be found on PNI s web site http www pnicorp com technology papers As previously mentioned PNI calibrates the accelerometers in its fac
61. sMode frame ID 22 4 This frame commands the Trax to stop data output when in Continuous Acquisition Mode The frame has no payload TRAX User Manual r05 Page 46 of 60 kGetDataResp frame ID 5 4 The response to kGetData and kStartContinuousMode is kGetDataResp The specific data fields that will be output ID 1 Value ID 1 etc should have been previously established by the kSetDataComponents command frame Payload ID Count Value ID 1 Value ID 2 Value ID 3 Ulnt8 Ulnt8 ID Specific Ulnt8 ID Specific Ulnt8 ID Specific Example If heading and heading status are set to be output per the kSetDataComponents command the payload would look like Payload ID Count Heading ID Heading Heading Heading Float32 Status ID Status Ulnt8 7 6 Calibration Commands 7 6 1 User Calibration Commands First note that in order to perform a user calibration it is necessary to place the Trax in Compass Mode as discussed in Section 7 7 Note that Trax allows for a maximum of 12 calibration points kStartCal frame ID 104 This frame commands the Trax to start user calibration with the current sensor acquisition parameters internal configurations and FIR filter settings Payload CalOption Payload Value 10 or OA Full Range Calibration default 204 or 14 2D Calibration UInt32 30 or 1E Hard Iron Only Calibration 40g or 28 Limited Tilt Range Calibration 100 or 64
62. since the SampleDelay does not include actual acquisition time kSetAcqParamsDone frame ID 26 4 This frame is the response to kSetAcqParams frame The frame has no payload kGetAcqParams frame ID 254 This frame queries the unit for acquisition parameters The frame has no payload kGetAcqParamsResp frame ID 27 4 This frame is the response to kGetAcqParams frame The payload should contain the same payload as the kSetAcqParams frame 7 5 3 Data Components kSetDataComponents frame ID 34 This frame defines what data is output when kGetData is sent Table 7 5 summarizes the various data components and more detail follows this table Note that this is not a query for the device s model type and software revision see kGetModInfo The first byte of the payload indicates the number of data components followed by the data component IDs Note that the sequence of the data components defined by kSetDataComponents will match the output sequence of kGetDataResp Payload pean vi oe 0 J Ulnt8 Ulnt8 Ulnt8 Ulnt8 Example To query for heading and heading status the payload should contain TRAX User Manual r05 Page 44 of 60 Payload ID Count Heading ID Pitch ID Table 7 5 Component Identifiers Component Component ID Format kHeading 5 Float32 degrees kPitch 24 Float32 degrees kRoll 25 Float32 degrees kHeadingStatus 79 UInt8 value kQuaternion 77 4x Float32 quaternion
63. ssteceeeesteeeeeees 3 Table 3 3 I O Characteristics cccccccccsssssccesssssseesscseessscesseceesesssssessecesseesseaseeseses 3 Table 3 4 Environmental Requirements ccccesessceceeeeeccessesssaeeeeeesesseesssseaeees 4 Table 3 5 Mechanical Characteristics r resnnrrvrrannnnvnrenennrrnnneennvnvnsensrnesssnennrnsssennnn 4 Table 4 1 Trax Pin Descriptions rronrororrrnrroononnnnrnrrvrrnrrnnnnnnnnrnnsnnsnnsnnnnnnnnnrnrsnnenne 7 Table 5 1 Magnetic Calibration Mode Summary rrnnrnnnnnnnnnnnrnnvnnnnnnsnnnnnnnnrnnsene 13 Table 5 2 12 Point Full Range Calibration Pattern rssrrrnrannrvvnrerennrnnvrrrnnrreneen 15 Table 5 3 12 Point 2D Calibration Pattern ssuaanannrnnnrannvrvnnannnvvvnssnennvnnsnennrsense 16 Table 5 4 12 Point Limited Tilt Calibration Pattern rsrrrnrannrrvnrevennrnvrnrrnnrreneen 16 Table 5 5 6 Point Hard Iron Only Calibration Pattern srrrnrannrvrnnnvennrrvrrennrrenen 17 Table 7 1 Communication Port Configuration ssrrrrrrnnrrvnrannrrrnnrrrennrresrennrrensen 33 Table 7 2 Trax Binary Command Set ssrnnnnanonnvnnenennrnnneennnvnvnsennnnenssnennvnnssennrsenee 36 Table 7 3 Configuration Identifiers rrrnrannrrvnnnnennrrnnrrennvrvnrennrrenssrennenesssnnrsense 39 Table 7 4 Sample PointS ssrnrnranonnvnnneennvrvnsannnnvnssnennrnnnsennrnvnssnnnnennssnennvnsssennrsesee 40 Table 7 5 Component Identifiers ccccccesseececsssseececesseeeeceeseaeeceessaeeesesseneee
64. sured field strength on the x axis and y axis magnetic sensors Configuration Callbration Test Log Data Graph System Log HK FR Mr FR 2 437140083 3 149161577 2 41159000 a x 5 3 199940182 15 f f s 3 149 6 0 98775682 83 3 149913072 11800085 2 099172172 0 3449976491 2 41 464500 2 099264202 3450950193 2 412730364 2 040160894 3 150930408 2 411559466 I 32 3 15 J r Gi 2 4371 19865 pa iiia a v 15 0 8 3 F atosorol Cow Expert Frend F User Sample Court 250 ha Denotes settings changed but not yet applied Defaut Read Forty Save The Filt data and plot blue provides magnetic field strength measurements after the FIR filter taps are applied but prior to applying the user calibration coefficients The User data and plot red provides data after applying the user calibration coefficients In AHRS Mode the data and plots are identical while in Compass Mode there is an offset which represents PNI Sensor Corporation DOC 1016505 r05 TRAX User Manual March 2012 Page 31 of 60 the effect of the calibration coefficients The Graph Tab normally would be used in Compass Mode because of this The graph can be used to visually see hard and soft iron effects within the environment measured by the Trax as well as corrected output after a user calibration has been performed The data can be saved to a txt log file by clicking lt Export gt
65. t Exponent lt 255 Signed 32 Bit Integer SInt32 SInt32 based parameters are signed 32 bit numbers 2 s compliment Bit 31 represents the sign of the value where 0 positive and 1 negative 31 24 23 1615 87 0 msb Isb Big Endian 7 0 15 8 23 1631 24 Isb msb Little Endian TRAX User Manual r05 Page 34 of 60 Signed 16 Bit Integer SInt16 SInt16 based parameters are signed 16 bit numbers 2 s compliment Bit 15 represents the sign of the value where 0 positive and 1 negative 15 87 0 7 0 15 8 msb Isb Isb msb Big Endian Little Endian Signed 8 Bit Integer SInt8 UInt8 based parameters are unsigned 8 bit numbers Bit 7 represents the sign of the value where 0 positive and 1 negative 7 0 byte Unsigned 32 Bit Integer Ulnt32 UInt32 based parameters are unsigned 32 bit numbers 31 24 23 1615 87 0 msb Isb Big Endian 7 0 15 8 23 1631 24 Isb msb Little Endian Unsigned 16 Bit Integer Ulnt16 Ulnt 16 based parameters are unsigned 16 bit numbers 15 87 0 7 0 15 8 msb Isb Isb msb Big Endian Little Endian Unsigned 8 Bit Integer Ulnt8 UInt8 based parameters are unsigned 8 bit numbers PNI Sensor Corporation DOC 1016505 r05 TRAX User Manual March 2012 Page 35 of 60 byte Boolean Boolean is a 1 byte parameter that MUST have the value 0
66. t allow limitations on how long an implied warranty lasts or the exclusion or limitation of incidental or consequential damages so the above limitations or exclusions may not apply to you This warranty gives you specific legal rights and you may have other rights that vary by state or province PNI Sensor Corporation DOC 1016505 r05 TRAX User Manual March 2012 Page 1 of 60 2 Introduction Thank you for purchasing PNI Sensor Corporation s Trax attitude amp heading reference system AHRS The Trax employs a proprietary Kalman filtering algorithm that intelligently fuses PNI s patented Reference Magnetic Sensors with a 3 axis gyroscope and 3 axis accelerometer The result is an orientation device that provides accurate heading information under a wide variety of conditions including its ability to overcome errors normally caused by erratic motion and or changes in the local magnetic field The advanced features of the Trax make it ideal for a variety of applications including e Unmanned Ground Vehicles UGV Robots and Unmanned Conversions e Unmanned Underwater Vehicles UUV Autonomous Gliders and ROV s We re sure the Trax will help you to achieve the greatest performance from your system Thank you for selecting the Trax TRAX User Manual r05 Page 2 of 60 3 Specifications 3 1 Characteristics amp Requirements Table 3 1 Performance Specifications in AHRS Mode Parameter Value
67. to kSetFIRFilters The frame has no payload kGetFIRFilters frame ID 134 This frame queries the FIR filter settings for the sensors Byte 1 should be set to 3 and Byte 2 should be set to 1 Payload Byte 1 Byte 2 Ulnt8 Ulnt8 kGetFIRFiltersResp frame ID 144 This is the response to kGetFIRFilters and it has the same payload definition as kSetFIRFilters 7 7 3 Power Down Up For certain applications it is desirable to conserve battery power To maintain accurate heading readings in AHRS Mode generally requires continual sensor updates to the Kalman algorithm However this is not the case in Compass Mode wherein readings may be taken only when heading information is desired Consequently when in Compass Mode the Trax may be powered down when heading data is not required kPowerDown frame ID 154 This frame is used to power down the module The frame has no payload The command will power down all peripherals including the sensors microprocessor and RS 232 driver However the driver chip has a feature to keep the Rx line enabled The Trax will power up when it receives any signal on the native UART Rx line kPowerDownDone frame ID 28 4 This frame confirms the Trax received a command to power down The frame has no payload kPowerUpDone frame ID 234 This frame confirms the Trax received a command to power up The Trax will power up when it receives any signal on the native UART Rx line The frame has no payload TRAX
68. tory prior to shipment But over time the bias and offset of the accelerometers will drift PNI Sensor Corporation TRAX User Manual March 2012 For this reason PNI DOC 1016505 r05 Page 17 of 60 recommends the accelerometers be recalibrated every 6 to 12 months The user may return the Trax to PNI for accelerometer calibration or the user may perform a user accelerometer calibration The remainder of this section covers the user accelerometer calibration The requirements for a good user accelerometer calibration differ significantly from the requirements for a good magnetic calibration Specifically a good accelerometer calibration involves the Trax experiencing a wide range of pitch and roll values preferably seeing both 180 of pitch and 180 of roll Also it is necessary that the Trax be held very still during an accelerometer calibration If possible PNI recommends using a fixture to hold the device during calibration although resting the Trax on a hard surface normally is sufficient On the other hand the Trax does not need to be incorporated in the user s host system to perform a user accelerometer calibration which significantly simplifies calibration when compared to magnetic calibration Figure 5 2 shows the two basic starting positions for the recommended 18 point calibration pattern Starting with the Trax as shown on the left in Figure 5 2 rotate the device about its Z axis such that it sits on each of its 4 e
69. udio can capture measurement data and then export it to a text file Configuration Calteation Test Log Date Gaph System Log Courts ms Pitch 1606 Ral 1625 Papp 1670 Mag 1998 Magt 1750 Accel 1776 Actel ane 1825 ov Q 15 3590 13 5371 emper aise 12 2853 Distortion 13 5583 33 3417 11 5306 12 0574 12 8576 13 8462 14 9878 16 1835 17 022 Farosat Denotes settings changed but not yet applied bear Read any Seve TRAX User Manual r05 Page 30 of 60 To acquire data and export it follow the procedure below e Select the parameters you wish to log in the window on the left Use Shift Click and Ctrl Click to select multiple items In the screen shot above Heading Pitch Roll and Heading Status were selected Note that Heading Status can be 0 1 or 2 corresponding to green yellow or red e Click the lt Start gt button to start logging The lt Start gt button changes to a lt Stop gt button after data logging begins e Click the lt Stop gt button to stop logging data e Click the lt Export gt button to save the data to a file e Click the lt Clear gt button to clear the data from the window Note that the Distortion log indicates if the magnetic field is gt 4125 uT for any of the magnetic sensors It is only applicable in Compass Mode and will always read FALSE in AHRS Mode 6 8 Graph Tab The Graph Tab provides a plot of the mea
70. with an emphasis on the heading distribution The score should be 0 Significant clumping or a lack of sample points in a particular section can result in a poor score Distribution is not calculated for an Accelerometer Calibration Tilt Error Indicates if the Trax experienced sufficient tilt during the calibration taking into account the calibration method The score should be 0 Tilt Error is not calculated for an Accelerometer Calibration Tilt Range This reports the larger of either half the full pitch range or half the full roll range of all sample points For example if the Trax is pitched 10 to 20 and rolled 25 to 15 the Tilt Range value would be 20 as derived from 25 15 2 For Full Range Calibration and Hard Iron Only Calibration this should be 45 For 2D Calibration this ideally would be 2 For Limited Tilt Range Calibration the value should be as large as possible given the user s constraints Tilt Range is not calculated for an Accelerometer Calibration Mag Factory Reset amp Accel Factory Reset Clicking the Mag Factory Reset and or Accel Factory Reset will reset the calibration coefficients to those established at PNI Note that the mag factory coefficients will not take into account magnetic influences inherent in the host system which could result in very large heading errors And the accel factory coefficients will not correct for accelerometer drift which may become significant over

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