OXTS xNAV650, Hardware Manual

Page 1: ...xNAV650 Hardware Manual 20 Years Navigation Experience in one small INS ...

Page 2: ... Limited All brand names are trademarks of their respective holders The software is provided by the contributors as is and any express or implied warranties including but not limited to the implied warranties of merchantability and fitness for a particular purpose are disclaimed In no event shall the contributors be liable for any direct indirect incidental special exemplary or consequential damag...

Page 3: ... will be made by Oxford Technical Solutions Limited personnel or by personnel expressly authorised by Oxford Technical Solutions Limited for this purpose In no event will Oxford Technical Solutions Limited be liable for any indirect incidental special or consequential damages whether through tort contract or otherwise This warranty is expressly in lieu of all other warranties expressed or implied ...

Page 4: ...nate frame 14 Interfaces 15 Main connector 15 PPS 16 Serial 16 Digital I O 17 User cable 17 Antennas 18 Internal storage 18 Ethernet configuration 19 Connection details for ethernet configuration 19 Best practices 20 Mounting 20 Orientation and alignment 20 Dual antenna systems 21 Multipath effects on dual antenna systems 22 Antenna placement and orientation 22 xNAV650 orientation and alignment 23...

Page 5: ...ure 7 xNAV650 user cable 17 Figure 8 xNAV650 mounting points mm 20 Figure 9 Dual antenna orientations 22 Figure 10 Windows Firewall warning message 29 Figure 11 Schematic of the strapdown navigator 30 Figure 12 NAVconfig LiDAR Scanner tab 33 Figure 13 The PPS Triggers tab in NAVconfig 34 List of tables Table 1 Supplementary manuals 7 Table 2 xNAV650 scope of delivery 8 Table 3 xNAV650 points of in...

Page 6: ...Solutions Ltd http www oxts com Page 6 of 42 Table 15 NAVsuite components 28 Table 16 Hardware integration manuals for surveying devices 32 Table 17 Epoch time configurations 35 Table 18 Time epoch advanced commands 36 ...

Page 7: ...this manual Table 1 lists related manuals and where to find them The xNAV650 Quick Start Guide is another useful tool for using your INS system Table 1 Supplementary manuals Manual Description OxTS Georeferencer Use OxTS Georeferencer to calibrate your setup and create pointclouds https support oxts com hc en us articles 360016436060 NAVconfig Use NAVconfig to configure the settings on your INS an...

Page 8: ...ith the items listed below in the basic kit Other items such as antennas and antenna cables are provided separately Table 2 xNAV650 scope of delivery Item xNAV650 basic kit xNAV650 inertial navigation system Software USB Quick start guide Ethernet cable 2 m Ethernet cross coupler Declaration of conformity ...

Page 9: ...her the L1 GPS frequency 1575 MHz or L2 1228 MHz The xNAV650 conforms to the requirements for CE The xNAV650 is certified for use with GNSS antennae with a gain of less than or equal to 35 dB Regulator testing standards EMC BS EN 61326 2 1 2013 Electrical equipment for measurement control and laboratory use BS EN 301 489 19 v2 1 1 2019 04 Electro Magnetic Compatibility EMC standard for radio equip...

Page 10: ...r antenna baselines and ensures stable heading performance even when stationary and during low dynamics The custom built quad IMU array consists of four individual IMU sensors that each combine 6 axis MEMS gyros and accelerometers providing improved performance noise reduction and redundancy The sensor fusion between the GNSS receivers and inertial sensors is done seamlessly in real time for a con...

Page 11: ...50 top view Table 3 xNAV650 points of interest Label number Description 1 Main I O connector 15 way Micro D o Power o Ethernet o PPS o Serial TX RX o Digital I O signal 1 2 configurable 2 Primary GNSS connector SMA 3 Secondary GNSS connector SMA 4 Measurement origin point 5 LEDs ...

Page 12: ...er has not yet output a valid time position or velocity Red The GNSS receiver has locked on to satellites and has adjusted its clock to valid time 1PPS output now valid The INS is ready to initialise Orange The INS has initialised and data is being output but the system is not yet real time the Kalman filter delay is a few seconds It takes 10 seconds for the system to become real time Green The IN...

Page 13: ... Figure 3 shows the outer dimensions of the xNAV650 the mounting points and the measurement origin point When making measurements required in the configuration files measurements should be made from the origin point Figure 3 xNAV650 dimensions and measurement origin point mm ...

Page 14: ...where the positive X axis points forwards the positive Y axis points right and the positive Z axis points down The xNAV650 can be mounted in any orientation it is not necessary for its axes to match those of the host vehicle The configuration file will specify the transformation from the IMU frame to the vehicle frame Figure 4 xNAV650 coordinate frame axes ...

Page 15: ...ower supply 2 Supply P Power supply 3 Serial I O Serial RS232 RX 4 Serial I O Serial RS232 TX 5 ERX I Ethernet receive 6 ERX I Ethernet receive 7 ETX O Ethernet transmit 8 ETX O Ethernet transmit 9 I O signal 2 I O Configurable I O Contact OxTS for options 10 I O signal 1 I O Configurable I O Contact OxTS for options 11 Signal ground isolated P Isolated signal ground 12 PPS isolated O Pulse per se...

Page 16: ... high No more than 10 mA should be drawn from this output Table 8 PPS electrical specifications PPS Typical Min Max Output Voltage High V 3 3 2 3 3 Output Voltage Low V 0 0 8 Output Current mA 2 The signal is configurable to the rising or falling edge For details please refer to the support article for NAVconfig or check the hardware section of this manual Figure 6 PPS waveform Serial The serial i...

Page 17: ...le The standard xNAV650 user cable is designed for quick access to the main interfaces Figure 7 shows the cable diagram and Table 11 shows the pin descriptions for the interface connectors At the end of this manual there is a full page drawing of the user cable provided Power lines should be correctly terminated and insulated and wired up with a fuse somewhere between the unit and power source bef...

Page 18: ...b Galileo signals and B1 and B2 Beidou signals should be used for optimal performance and improved reliability The xNAV650 is certified for use with GNSS antennae with a gain of less than or equal to 35 dB When using the xNAV650 in a dual antenna configuration it is recommended to use the same type of antenna with the same cable lengths for both the primary and secondary receivers A suitable groun...

Page 19: ...ternative configurations require FTP to put the configuration files on to the xNAV650 The default username and password are both user The xNAV650 outputs its data over ethernet using a UDP broadcast The use of a UDP broadcast allows everyone on the network to receive the data sent by the xNAV650 The data rate of the UDP broadcast is 100 Hz Each xNAV650 is configured with a static IP address to ena...

Page 20: ...e xNAV650 where it is in direct sunlight as this may cause the case to exceed the maximum temperature specification Orientation and alignment The orientation of the xNAV650 in the vehicle is normally specified using three consecutive rotations that transform the system to the vehicle s co ordinate frame Refer to Figure 4 for directions of axes The order of the rotations is o Heading z axis rotatio...

Page 21: ...ntenna orientation should be known to within 5 For wider separations the secondary antenna orientation angle needs to be more accurate 7 Once the RTK Integer solution is available the xNAV can start to use the dual antenna solution to improve heading The level of correction that can be applied depends on how accurately the angle of the secondary antenna is known compared to the inertial sensors 8 ...

Page 22: ... INS in GNSS conditions where multipath effects are prevalent lots of objects particularly buildings around then it is worth using higher end antennas that have a greater signal filtering capability Antenna placement and orientation For optimal performance it is essential for the GNSS antenna s to be mounted where they have a clear uninterrupted view of the sky and on a suitable ground plane such ...

Page 23: ... GNSS signal repeaters that are designed to accurately repeat the GNSS signal Cable length options are available in 1 m 5 m and 15 m lengths This is important because the signal can deteriorate over longer cables and the signals are expected to match xNAV650 orientation and alignment The orientation of the xNAV in the vehicle is normally specified using three consecutive rotations that rotate the ...

Page 24: ...e The distance from the xNAV measurement point to the primary GNSS antenna must be known by the system to a precision of five millimetres or better The vibration of the system relative to the vehicle cannot allow this to change by more than five millimetres The system will estimate this value itself in dynamic conditions For dual antenna systems the system must know the relative orientation of the...

Page 25: ...mperature 40 to 70 C Calibration temperature 20 to 70 C Vibration 10 500 Hz 1 42 g RMS Shock 15 g 11 ms half sine Internal storage 32 GB Data logging rate 3 MB s Data output rate 100 Hz with 200 and 250 Hz options a To achieve specification relevant differential corrections from a base station or NTRIP are required b With two meter antenna separation Wider separation will improve accuracy up to ar...

Page 26: ...nna systems Heading accuracy The heading accuracy that can be achieved by the dual antenna system in the xNAV650 is about 0 2 1σ per metre of separation in ideal open sky conditions The system can provide these accuracies in static and dynamic conditions A two metre separation is required to reach the accuracy listed in Table 11 The maximum recommended separation is five metres at which it may be ...

Page 27: ...r and gyro sensors used in the xNAV650 as well as the xNAV650 navigation system as a whole does not fall under the requirements for controlled items on the Commerce Control List CCL As such the xNAV650 is designated ECCN 7A994 meaning no licence is required for export or reexport ...

Page 28: ...eprocessed It can export NCOM XCOM and CSV file formats NAVgraph Used to graph NCOM XCOM and RCOM files created in post process It can display graphs cursor tables and map plots and data can be exported in CSV or KML Google Earth format NAVbase Used to configure and manage xNAV Base S and GPS Base base stations which can be used to achieve RTK integer level position accuracy Manuals This folder co...

Page 29: ...tions Ltd http www oxts com Page 29 of 42 Figure 10 Windows Firewall warning message Ensure both Private and Public networks are selected to ensure the software can continue functioning when moving from one type to another ...

Page 30: ...e strapdown navigator The angular rates have their bias and scale factor corrections from the Kalman filter applied Earth rotation rate is also subtracted to avoid the 0 25 per minute rotation of the Earth The transport rate is also corrected this is the rate that gravity rotates by due to the vehicle moving across the earth s surface and it is proportional to horizontal speed Finally the angular ...

Page 31: ... filter used in the xNAV is able to apply corrections to several places in the strapdown navigator including position velocity heading pitch roll angular rate bias and scale factor and acceleration bias Using a model of how one measurement affects another the Kalman filter is able to estimate states where it has no direct measurement Position and velocity are compensated directly but other measure...

Page 32: ...com hc en us articles 360016515759 PTP Quick Start Guide Beta For information on setting up a configuration for your INS to work with survey devices you can follow the guides above and the NAVconfig support guide Many devices will require to receive NMEA messages and a time synchronisation For the xNAV650 time synchronisation can be done using PPS or using PTP See the manual at the hyperlink above...

Page 33: ...ces require to receive PPS synchronisation and NMEA data This can be easily configured using NAVconfig The hardware setup will also have to be made to support this via a suitable cable Furthermore ensure that the PPS requirements for the device are the same as the INS output If you require TTL input for example you will need an adapter between the two devices In NAVconfig PPS and NMEA can be set i...

Page 34: ...terfaces section These are set on the right hand side and can be input output triggers or IMU sync triggers PPS signals can be set to have the active edge in the falling or rising edge in this tab also Check your device s manual to determine which is required NCOM navigation data packets can be set to output on triggers in the ethernet tab Figure 13 The PPS Triggers tab in NAVconfig ...

Page 35: ...l be viewable in software such as Wireshark as PTPv2 protocol packets OxTS devices get their time solution from GNSS satellites which use very accurate atomic clocks The time that OxTS devices receive from the satellites is the number of seconds since midnight January 5th January 6th 1980 This is known as the GPS epoch and from this the device can calculate the current date and time By default whe...

Page 36: ...ing timestamps in UTC The following command was required to generate an accurate pointcloud lidar_time_offset 315964785000000000 If the RT3000 v3 was instead in Unix time mode the following command would be required lidar_time_offset 18000000000 Finally ensure that your survey device is correctly configured to anticipate PTP time synchronisation Cable modification The standard user cable for the x...

Page 37: ...igital IO Only connect Wheelspeed or Triggers at any one time connects isolated and non isolated system grounds Micro d pin Colour Signal Female d type pin 12 W BRN PPS ISO 1 9 GRY I O Signal 2 Rx 2 3 10 WHT I O Signal 1 Tx 4 5 13 W RED Signal Ground 6 5 11 W BLK Signal Ground ISO 6 5 Serial For xNAV650 no isolation in this product Micro d pin Colour Signal Male d type pin 3 RED CAN ISO RS232 Rx 2...

Page 38: ...Oxford Technical Solutions Ltd http www oxts com Page 38 of 42 Appendix 2 Drawings ...

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Page 40: ...Oxford Technical Solutions Ltd http www oxts com Page 40 of 42 Revision history ...

Page 41: ...d Technical Solutions Ltd http www oxts com Page 41 of 42 Revision history Revision Comments 201117 Draft version last updated 210204 Draft version for website release 210311 Final release for product launch ...

Page 42: ...Oxford Technical Solutions Ltd ...