USER GUIDE. Trimble BD935-INS GNSS Receiver Module

Transcription

1 USER GUIDE Trimble BD935-INS GNSS Receiver Module Version 5.11 Revision A December

2 Corporate Office Trimble Navigation Limited Integrated Technologies 510 DeGuigne Drive Sunnyvale, CA USA Legal Notices , Trimble Navigation Limited. All rights reserved. Trimble and the Globe & Triangle logo are trademarks of Trimble Navigation Limited, registered in the United States and in other countries. CMR+, EVEREST, Maxwell, and Zephyr are trademarks of Trimble Navigation Limited. Microsoft, Internet Explorer, Windows, and Windows Vista are either registered trademarks or trademarks of Microsoft Corporation in the United States and/or other countries. All other trademarks are the property of their respective owners. Support for Galileo is developed under a license of the European Union and the European Space Agency (BD910/BD920/BD930/BD935/BD970/BD982/BX935/BX982). Release Notice This is the December 2015 release (Revision A) of the BD935-INS GNSS Receiver Module User Guide. It applies to version 5.11 of the receiver firmware. BD935-INS GNSS Receiver Module User Guide 2

3 Contents Contents 3 1 Introduction 5 About the BD935-INS GNSS receiver 6 BD935-INS receiver features 7 Default settings 9 Technical support 10 2 Specifications 11 Positioning specifications 12 Performance specifications 13 Physical and electrical characteristics 14 Environmental specifications 14 Communication specifications 15 3 Mechanical Drawings 16 BD935-INS module mechanical drawing 17 BD935-INS evaluation I/O board 19 4 Electrical System Integration pin header connector pinouts 21 1PPS and ASCII time tag 24 ASCII time tag 25 Power input 26 Antenna power output 26 LED control lines 27 Power switch and reset 28 Event 29 Serial port 30 USB 30 Ethernet 35 Recommended electrical specifications for the antenna 35 ESD protection 35 5 Installation 36 Unpacking and inspecting the shipment 37 Installation guidelines 37 Interface board evaluation kit 39 Routing and connecting the antenna cable 40 LED functionality and operation 41 BD935-INS GNSS Receiver Module User Guide 3

4 Contents 6 Reference Frames and Offset Measurements 42 Reference frames and offset measurements overview 43 IMU Body Frame definition 44 Reference Body Frame definition 44 Vehicle Body Frame 45 Lever Arm definitions 46 Receiver configuration 49 7 Troubleshooting Receiver Issues 50 Glossary 52 BD935-INS GNSS Receiver Module User Guide 4

5 CHAPTER 1 Introduction About the BD935-INS GNSS receiver BD935-INS receiver features Default settings Technical support This manual describes how to set up, configure, and use the Trimble BD935-INS GNSS-Inertial receiver module. The receiver uses advanced navigation architecture to achieve real-time centimeter accuracies with minimal latencies. Even if you have used other GNSS-Inertial products before, Trimble recommends that you spend some time reading this manual to learn about the special features of this product. If you are not familiar with GNSS or GPS, visit the Trimble website ( BD935-INS GNSS Receiver Module User Guide 5

6 1 Introduction About the BD935-INS GNSS receiver The Trimble BD935-INS module is a powerful multi-constellation, multi-frequency GNSS receiver with on-board integrated inertial sensors. Taking advantage of Trimble s expertize in both GNSS and Inertial technology the Trimble BD935-INS module has been designed for applications requiring continuous centimeter accuracy in a compact package. By integrating inertial sensors on the same module, robust high accuracy positions are produced in all environments. A simple intuitive web interface and interface protocol allows a variety of dynamic models to be supported. The GNSS components are fully shielded. This design ensures that the high quality signals are protected from the sources of EMI on the host platform. The Trimble BD935-INS supports both the triple frequency for the GPS and GLONASS constellations, and the dual frequency from BeiDou and Galileo. As the number of satellites in the constellations grows, the BD935-INS is ready to take advantage of the additional signals. This delivers the quickest and most reliable RTK initializations for 1 to 2 centimeter positioning. For applications that do not require centimeter accuracy, the BD935-INS integrated GNSS-Inertial engine delivers high accuracy GNSS/DGNSS positions in the most challenging environments such as urban canyons. Different configurations of the module are available. These include everything from a DGPS L1 unit through to a four-constellation triple-frequency RTK unit. Choose the receiver that suits your requirements. All features are password-upgradeable, allowing functionality to be upgraded as your requirements change. The receiver also supports Fault Detection and Exclusion (FDE) and Receiver, and Autonomous Integrity Monitoring (RAIM) for safety-critical applications. Key features include: High update rate position and orientation solutions Continuous positioning in GNSS denied environments Lever arm calculation from antenna to navigation point of interest Robust Moving Baseline RTK for precision landing on moving platforms Single antenna heading not influenced by magnetic field variations BD935-INS GNSS Receiver Module User Guide 6

7 1 Introduction BD935-INS receiver features The BD935-INS receiver has the following features: Position antenna based a on 336-channel Trimble Maxwell GNSS-Inertial technology: GPS: L1 C/A, L2E, L2C, L5 BeiDou: B1, B2 GLONASS: L1 and L2 C/A, L3 CDMA Galileo: E1, E5A, E5B, E5AltBOC QZSS: L1 C/A, L1 SAIF, L2C, L5 SBAS: L1 C/A, L5 Advanced MEMS inertial sensors High precision multiple correlator for GNSS pseudorange measurements Unfiltered, unsmoothed pseudorange measurement data for low noise, low multipath error, low time domain correlation and high dynamic response Very low noise GNSS carrier phase measurements with <1 mm precision in a 1 Hz bandwidth Proven Trimble low elevation tracking technology 1 USB 2.0 device port 1 LAN Ethernet port: Supports links to 10BaseT/100BaseT auto-negotiate networks All functions are performed through a single IP address simultaneously including web interface access and raw data streaming Network protocols supported: HTTP (web interface) NTP Server NMEA, GSOF, CMR over TCP/IP or UDP NTripCaster, NTripServer, NTripClient mdns/upnp Service discovery Dynamic DNS alerts Network link to Google Earth Support for external modems through PPP 2 x RS-232 ports (baud rates up to 115,200) BD935-INS GNSS Receiver Module User Guide 7

8 1 Introduction Up to 100 Hz raw measurement and position outputs Correction inputs/outputs: CMR, CMR+, scmrx, RTCM 2.1, 2.2, 2.3, 2.4, 3.X, 3.2. Note: The functionality to input or output any of these corrections depends on the installed options. Different manufacturers may have established different packet structures for their correction messages. Thus, the BD9xx receiver may not receive corrections from another manufacturer's receiver, and another manufacturer's receiver may not be able to receive corrections from the BD9xx receiver. Navigation outputs: ASCII: NMEA-0183: AVR; BPQ; DTM; EVT; GBS; GDP; GGA; GGK; GLL; GNS; GRS; GSA; GST; GSV; HDT; LLQ; PASHR; PJK; PJT; ROT; RMC; VGK; VHD; VTG; ZDA. Binary: Trimble GSOF. Control software: HTML Web browser (Google Chrome (recommended), Internet Explorer, Mozilla Firefox, Apple Safari, Opera) 1 pulse-per-second (1PPS) output Event Marker Input support Supports Fault Detection and Exclusion (FDE), Receiver Autonomous Integrity Monitoring (RAIM) Note Galileo support is developed under a license of the European Union and the European Space Agency. Note There is no public GLONASS L3 CDMA ICD. The current capability in the receivers is based on publicly available information. As such, Trimble cannot guarantee that these receivers will be fully compatible. BD935-INS GNSS Receiver Module User Guide 8

9 1 Introduction Default settings All settings are stored in application files. The default application file, Default.cfg, is stored permanently in the receiver, and contains the factory default settings. Whenever the receiver is reset to its factory defaults, the current settings (stored in the current application file, Current.cfg) are reset to the values in the default application file. These settings are defined in the default application file. Function Settings Factory default SV Enable - All SVs enabled General Controls Elevation mask 10 PDOP mask 99 RTK positioning mode Motion Low Latency Kinematic Ports Baud rate 38,400 Format Flow control 8-None-1 None Input Setup Station Any NMEA/ASCII (all supported messages) All ports Off Streamed Output All types Off Offset=00 RT17/Binary All ports Off Reference Position Latitude 0 Longitude 0 Altitude 0.00 m HAE Antenna Type Unknown Height (true vertical) Measurement method 0.00 m Antenna Phase Center 1PPS Disabled Event Ports Disabled BD935-INS GNSS Receiver Module User Guide 9

10 1 Introduction If a factory reset is performed, the above defaults are applied to the receiver. The receiver also returns to a DHCP mode, and security is enabled (with a default login of admin and the password of password ). To perform a factory reset: From the web interface, select Receiver Configuration / Reset and then clear the Clear All Receiver Settings option. Send the Command 58h with a 03h reset value. Technical support If you have a problem and cannot find the information you need in the product documentation, send an to GNSSOEMSupport@trimble.com. Documentation, firmware, and software updates are available at: BD935-INS GNSS Receiver Module User Guide 10

11 CHAPTER 2 Specifications Positioning specifications Performance specifications Physical and electrical characteristics Environmental specifications Communication specifications This chapter details the specifications for the receiver. Specifications are subject to change without notice. BD935-INS GNSS Receiver Module User Guide 11

12 2 Specifications Positioning specifications Note The following specifications are provided at 1 sigma level when using a Trimble Zephyr 2 antenna. These specifications may be affected by atmospheric conditions, signal multipath, and satellite geometry. Initialization reliability is continuously monitored to ensure highest quality. Feature Specification Initialization time Typically <10 seconds Initialization accuracy >99.9% Mode Accuracy Latency (at max. output rate) Maximum Rate Single Baseline RTK (<30 km) DGNSS m + 1 ppm horizontal m + 1 ppm vertical 0.1 deg Roll & Pitch 0.5 deg True Heading 0.25 m + 1 ppm horizontal 0.5 m + 1 ppm vertical 0.1 deg Roll & Pitch 0.5 deg True Heading <20 ms 100 Hz <20 ms 100 Hz SBAS m horizontal <20 ms 100 Hz 0.85 m vertical 0.1 deg Roll & Pitch 0.5 deg True Heading 1 GPS only and depends on SBAS system performance. FAA WAAS accuracy specifications are <5m 3DRMS. BD935-INS GNSS Receiver Module User Guide 12

13 2 Specifications Performance specifications Note The Time to First Fix specifications are typical observed values. A cold start is when the receiver has no previous satellite (ephemerides/almanac) or position (approximate position or time) information. A warm start is when the ephemerides and last used position is known. Feature Specification Time to First Fix (TFF) Cold Start <45 seconds Warm Start Signal Re-acquisition <30 seconds <2 seconds Velocity Accuracy 1 Horizontal m/sec Vertical m/sec Maximum Operating Limits 2 Velocity 515 m/sec Altitude 18,000 m Acceleration 11 g 1 1 sigma level when using a Trimble Zephyr 2 antenna. These specifications may be affected by atmospheric conditions, signal multipath, and satellite geometry. Initialization reliability is continuously monitored to ensure highest quality. 2 As required by the US Department of Commerce to comply with export licensing restrictions. BD935-INS GNSS Receiver Module User Guide 13

14 2 Specifications Physical and electrical characteristics Feature Dimensions (L x W x H) Power Weight Connectors Antenna LNA Power Output Minimum required LNA gain Specification 60 mm x 67 mm x 15 mm 5 V DC to 28 V DC Typical 3.5 W (L1/L2 GPS + L1/L2 GLONASS) 60 grams I/O: 44-pin SAMTEC TMM S-D (rated for >1000 cycles) Can be mated with but not limited to: SAMTEC CLT, ESQT, MMS, SMM, SQT, SQW, TCSD, TLE, or TLSD types of connectors Antenna: MMCX receptacle (Rated for 500 cycles) Output voltage: 3.3 to 5 V DC Current rating: 200 ma Maximum current: 400 ma 31 db Note This receiver is designed to operate with the Zephyr Model 2 antenna which has a gain of 50 db. Higher-gain antennas have not been tested. Environmental specifications Feature Temperature Specification Operating: -40 C to 75 C (-40 F to 167 F) Storage: -55 C to 85 C (-67 F to 185 F) Vibration Mechanical shock Operating humidity MIL810F, tailored Random 6.2 grms operating Random 8 grms survival MIL810D +/- 40 g operating +/- 75 g survival 5% to 95% R.H. non-condensing, at +60 C (140 F) BD935-INS GNSS Receiver Module User Guide 14

15 2 Specifications Communication specifications Feature Specification Communications 1 LAN port Supports links to 10BaseT/100BaseT networks. All functions are performed through a single IP address simultaneously including web interface access and data streaming. 2 x RS-232 ports Baud rates up to 115,200 1 USB 2.0 port Receiver position update rate 1 Hz, 2 Hz, 5 Hz, 10 Hz, 20 Hz, 50 Hz and 100 Hz positioning Correction data input CMR, CMR+, scmrx, RTCM , RTCM 3.X, 3.2 Correction data output Data outputs CMR, CMR+, scmrx, RTCM 2.0 DGPS (select RTCM 2.1), RTCM , RTCM 3.X, 3.2 1PPS, NMEA, Binary GSOF, ASCII Time Tags BD935-INS GNSS Receiver Module User Guide 15

16 CHAPTER 3 Mechanical Drawings BD935-INS module mechanical drawing BD935-INS evaluation I/O board The drawings in this section show the dimensions of the receiver. Refer to these drawings if you need to build mounting brackets and housings for the receiver. BD935-INS GNSS Receiver Module User Guide 16

17 3 Mechanical Drawings BD935-INS module mechanical drawing Note Dimensions are shown in millimeters (mm). Dimensions shown in brackets are in inches. BD935-INS GNSS Receiver Module User Guide 17

18 3 Mechanical Drawings The following drawing shows the 3D view of the board. BD935-INS GNSS Receiver Module User Guide 18

19 3 Mechanical Drawings BD935-INS evaluation I/O board ❶ GNSS Receiver module ❺ Receiver status ❾ LEDs Ethernet ❷ Serial Port 1 ❻ USB Type A ❿ Serial port 2 ❸ Serial Port 3 ❼ USB Type B ⓫ Power switch and Reboot button ❹ 1 PPS ❽ Event Pins ⓬ Not used BD935-INS GNSS Receiver Module User Guide 19

20 CHAPTER 4 Electrical System Integration 44-pin header connector pinouts 1PPS and ASCII time tag ASCII time tag Power input Antenna power output LED control lines Power switch and reset Event Serial port USB Ethernet Recommended electrical specifications for the antenna ESD protection BD935-INS GNSS Receiver Module User Guide 20

21 4 Electrical System Integration 44-pin header connector pinouts The 44-pin SAMTEC TMM S-S-MW has the following pinouts. Pin Signal name Description Integration notes 1 GND Common ground connection 2 LED2- LED driver for power/data logging 3 LED1- LED driver for RTK corrections Connect to common ground. Active high 3.3 V 4 ma. Active high 3.3 V 4 ma. 4 LED1+ LED driver for tracking SVs Active high 3.3 V 4 ma. 5 USB_VBUS USB 5 V power 5 V output to power USB devices, enabled by USB_ID. 6 IMU_LED LED driver for IMU status Active high 3.3 V 4 ma. 7 5V Output of 5 V switching regulator Do not connect. For Boxster I/O board. 8 EVENT1 Event1 input 3.3 V input. 9 USB_DM USB D- differential signal USB_DM and USB_DP need to be differentially routed. BD935-INS GNSS Receiver Module User Guide 21

22 4 Electrical System Integration Pin Signal name Description Integration notes 10 GND Common ground connection Connect to common ground. 11 USB_DP USB D+ differential signal USB_DM and USB_DP need to be differentially routed. 12 GND Common ground connection Connect to common ground. 13 MX_PPS2 One pulse-per-second 3.3 V output, 8us width, <20ns rise time. 14 USB_ID Cable detect for USB device or host 3.3 V input, floating = USB device mode and VBUS is OFF, 3.3 V = USB device mode and VBUS is OFF, 0 V = USB host mode and VBUS is 5 V. 15 Event0 Event0 input 3.3 V input. 16 DMI1 Quadrature 2-pin DMI input 3.3 V input, DMI1 leads DMI2 in forward direction. 17 COM4_CTS Serial port 4 Clear To Send 3.3 V input. 18 COM4_RTS Serial port 4 Ready To Send 3.3 V output. 19 COM1_RX_RS232 Serial port 1 receive input RS232 voltage level input. 20 COM1_TX_RS232 Serial port 1 transmit output RS232 voltage level output. 21 COM4_RX Serial port 4 receive input 3.3 V input. 22 COM4_TX Serial port 4 transmit output 23 GND Common ground connection 3.3 V output. Connect to common ground. 24 PWR_ON Graceful shutdown control Active high. 0 V = OFF/start graceful shutdown, Floating = ON, 3-32 V = ON 25 GND Common ground connection 26 GND Common ground connection 27 ET_RD+ Ethernet differential receive plus (+) Connect to common ground. Connect to common ground. Magnetics on-board, ET_RD+ and ET_ RD- need to be differentially routed. BD935-INS GNSS Receiver Module User Guide 22

23 4 Electrical System Integration Pin Signal name Description Integration notes 28 GND Ground Digital Ground Ground Digital Ground. 29 ET_RD- Ethernet differential receive minus (-) 30 GND Common ground connection 31 ET_TD+ Ethernet differential transmit plus. 32 GND Common ground connection 33 ET_TD- Ethernet differential transmit minus. 34 GND Common ground connection Magnetics on-board, ET_RD+ and ET_ RD- need to be differentially routed. Connect to common ground. Magnetics on-board, ET_TD+ and ET_ TD- need to be differentially routed. Connect to common ground. Magnetics on-board, ET_TD+ and ET_ TD- need to be differentially routed. Connect to common ground. 35 RESET_IN BD930 reset Active low, internally pulled high to 3.3 V, 0 V = held in reset. 36 GND Common ground connection 37 GND Common ground connection Connect to common ground. Connect to common ground. 38 DMI2 Quadrature 2-pin DMI input 3.3 V input, DMI1 leads DMI2 in forward direction. 39 CAN1_H CAN + differential signal CAN1_H and CAN1_L need to be differentially routed 40 CAN1_L CAN - differential signal CAN1_H and CAN1_L need to be differentially routed 41 GND Common ground connection 42 GND Common ground connection Connect to common ground. Connect to common ground. 43 EXT_PWR_IN Input power 6-32 V DC Connect pin together. 44 EXT_PWR_IN Input power 6-32 V DC Connect pin together. BD935-INS GNSS Receiver Module User Guide 23

24 4 Electrical System Integration 1PPS and ASCII time tag The receiver can output a 1 pulse-per-second (1PPS) time strobe and an associated time tag message. The time tags are output on a user-selected port. The leading edge of the pulse coincides with the beginning of each UTC second. The pulse is driven between nominal levels of 0.0 V and 3.3 V (see below). The leading edge is positive (rising from 0 V to 3.3 V). The receiver PPS out is a 3.3 V TTL level with a maximum source/sink current of 4 ma. If the system requires a voltage level or current source/sink level beyond these levels, you must have an external buffer. This line has ESD protection. The illustration below shows the time tag relation to 1PPS wave form: The pulse is about 8 microseconds wide, with rise and fall times of about 100 ns. Resolution is approximately 40 ns, where the 40 ns resolution means that the PPS shifting mechanism in the receiver can align the PPS to UTC/GPS time only within +/- 20 ns, but the following external factor limits accuracy to approximately ±1 microsecond: Antenna cable length Each meter of cable adds a delay of about 2 ns to satellite signals, and a corresponding delay in the 1PPS pulse. BD935-INS GNSS Receiver Module User Guide 24

25 4 Electrical System Integration ASCII time tag Each time tag is output about 0.5 second before the corresponding pulse. Time tags are in ASCII format on a user-selected serial port. The format of a time tag is: UTC yy.mm.dd hh:mm:ss ab Where: UTC is fixed text. yy.mm.dd is the year, month, and date. hh:mm:ss is the hour (on a 24-hour clock), minute, and second. The time is in UTC, not GPS. a is an integer number representing the position-fix type: 1 = time solution only 2 = 1D position and time solution 3 = currently unused 4 = 2D position and time solution 5 = 3D position and time solution b is the number of GNSS satellites being tracked. If the receiver is tracking 9 or more satellites, b will always be displayed as 9. Each time tag is terminated by a carriage return, line feed sequence. A typical printout looks like: UTC :21:16 56 UTC :21:17 56 UTC :21:18 56 Note If the receiver is not tracking satellites, the time tag is based on the receiver clock. In this case, a and b are represented by??. The time readings from the receiver clock are less accurate than time readings determined from the satellite signals. BD935-INS GNSS Receiver Module User Guide 25

26 4 Electrical System Integration Power input Item Power requirement Description The unit, excluding the antenna, operates at 8-32 V DC. The typical power consumption based on band usage is 3.5 W. Antenna power output Item Power output specification Short-circuit protection Description The antenna DC power is supplied directly from the BD935-INS MMCX antenna connection. The antenna output is rated to a maximum voltage of 5 V DC and can source a recommended 150 ma maximum. The antenna power is short-circuit protected, which will cut off antenna power if shorted. BD935-INS GNSS Receiver Module User Guide 26

27 4 Electrical System Integration LED control lines Item Description Driving LEDs The outputs are 3.3 V TTL level with a maximum source/sink current of 4 ma. An external series resistor must be used to limit the current. The value of the series resistor in Ohms is determined by: (3.3-Vf)/(If) > Rs > (3.3 V - Vf)/(.004) Rs = Series resistor If = LED forward current, max typical If of the LED should be less than 3 ma Vf = LED forward voltage, max typical Vf of the LED should be less than 2.7 V Most LEDs can be driven directly as shown in the circuit below: LEDs that do not meet If and Vf specification must be driven with a buffer to ensure proper voltage level and source/sink current. Power LED Satellite LED RTK Correction LED This active-high line indicates that the unit is powered on. This active-high line indicates that the unit has acquired satellites. A rapid flash indicates that the unit has less than 5 satellites acquired while a slow flash indicates greater than 5 satellites acquired. This line will stay on if the unit is in monitor mode. A slow flash indicates that the unit is receiving corrections. This will also flash when the unit is in monitor mode. IMU Navigation Status LED Status Unknown or No GNSS/INSS Solution Coarse Leveling Degraded Solution Aligned Solution Signal Status Off 5 Hz 2 Hz 1 Hz BD935-INS GNSS Receiver Module User Guide 27

28 4 Electrical System Integration Power switch and reset Item Power Switch Boot Monitor Switch Reset switch Description Driving PWR_ON, Pin 24, low will start the graceful shutdown of the board. This pin has to be kept low for the board to stay powered down. If left floating the board will be powered on. If driven 3-30 V the board will be powered on. Driving Boot_Monitor* test point low while the unit is starting will cause the receiver to go into the boot monitor. This keeps the application from loading. For normal operation, keep Boot_Monitor* floating. Driving Reset_IN*, Pin 35, low will cause the unit to reset. The unit will remain reset at least 30 ms after the Reset_IN* is deasserted. The unit remains powered while in reset. BD935-INS GNSS Receiver Module User Guide 28

29 4 Electrical System Integration Event Item Event 1 Event 2 Description Pin 8 is dedicated as an Event_In pin. This is a TTL only input; it is not buffered or protected for any inputs outside of 0 V to 3.3 V. It does have ESD protection. If the system requires event to handle a voltage outside this range, the system integrator must condition the signal prior to connecting to the unit. Pin 15 is dedicated as an Event_In pin. This is a TTL only input; it is not buffered or protected for any inputs outside of 0 V to 3.3 V. It does have ESD protection but if the system requires event to handle a voltage outside this range, the system integrator must condition the signal prior to connecting the unit. Trimble recommends adding a Schmitt trigger and ESD protection to the Event_In pin. This prevents any 'ringing' on the input from causing multiple and incorrect events to be recognized. U1 is Texas instrument: SN74LVC2G17 U2 is ON Semiconductor: NUP4301MR6T1G SN74LVC2G17 is also suitable for 5 V systems. It accepts inputs up to 5.5 V even when using 3.3 V VCC. Take care to make sure that I/O does not exceed 3.3 V. For more information, go to EventInput.html. BD935-INS GNSS Receiver Module User Guide 29

30 4 Electrical System Integration Serial port Item COM 1 TTL level no flow control COM 3 TTL level with flow control Description COM 1 is at 0 to 3.3 V TTL. If the integrator needs this port to be at RS-232 level, a proper transceiver powered by the same 3.3 V that powers the receiver needs to be added. For development using the I/O board, this COM port is already connected to an RS-232 transceiver. This is labeled Port 1 on the I/O board. All TTL-COM will support either 3.3 V CMOS or TTL levels. COM 3 is at 0 to 3.3 V TTL. If the integrator needs this port to be at RS-232 level, a proper transceiver powered by the same 3.3 V that powers the receiver needs to be added. For development using the I/O board, this COM port is already connected to an RS-232 transceiver. This is labeled Port 3 on the I/O board. All TTL-COM will support either 3.3 V CMOS or TTL levels. USB The CPU of the BD935-INS has two integrated USB PHYs. One PHY supports USB 2.0 OTG in high, full, and low-speed modes. The second PHY supports host-only configuration at low speed and full speed. If the OTG port is set to device mode, the BD930-UHF will behave like an external storage device to a PC. If the OTG port is in host mode, external memory can be connected to the BD935-INS to provide additional storage space. The port has ESD protection; however a USB 2.0-compliant common mode choke located near the connector should be added to ensure EMI compliance. The USB_ID pin (Pin 14) is the one that determines if the BD935-INS receiver will act as a host (a digital 1 ) or as a device (a digital 0 ). The BD935-INS receiver has a pull-up resistor on this line, so this pin should be left floating for the receiver to act as a device. BD935-INS GNSS Receiver Module User Guide 30

31 4 Electrical System Integration USB OTG reference design To be OTG compliant, the connector must be MICRO AB. An OTG-compliant cable has both A and B ends. When the B side of the cable is inserted, the ID pin is not connected (floating) and the BD935- INS will enter device mode. The A side cable connects the ID pin to ground, which enables the BD935-INS to act as a USB host. To reduce EMI, place a USB 2.0 compliant common mode choke on the data lines. The choke should be located near the USB MICRO AB connector to ensure best EMI performance. In addition, Trimble recommends using an L-C-L type EMI filter for the output power. For product robustness and protection, place ESD protection diodes on both USB_VBUS and USB_ OTG_ID lines. The BD935-INS has no internal ESD protection on the USB data lines. To ensure best USB high-speed performance, careful consideration of PCB routing and placement practices must be taken: Place components so the trace length is minimized. Do not have stubs on data lines more than Route data lines differentially with as much parallelism as possible. Data lines should be nearly the same length. Data lines must be controlled to 90 Ohms differential impedance, and 45 Ohms single ended impedance. Route over continuous reference plane (either ground or power). For more detailed information, refer to the Intel High Speed USB Platform Design Guidelines. BD935-INS GNSS Receiver Module User Guide 31

32 4 Electrical System Integration Alternate OTG reference This is the USB design implemented on the development I/O board. There are both type A (J9) and type B connectors (J10). When a host (a PC, etc.) is plugged into J10, the design recognizes the +5 V on the bus provided by the host. The USB_OTG_ID pin is driven low representing that BD935-INS is acting as a device. When no host is plugged into the I/O board, USB_OTG_ID is driven high through the 1 KOhm pull-up resistor. This causes BD935-INS to be in Host mode. BD935-INS GNSS Receiver Module User Guide 32

33 4 Electrical System Integration USB host only reference design For USB host-only support, a type-a connector is required. Since dynamic role switching is not supported, the ID pin should be grounded on the BD935-INS. See the OTG reference design section above for additional recommendations for EMI, ESD protection, and layout considerations. USB device only reference design For device only operation, the USB_OTG_ID pin is left floating. The integrator is required to pull USB_OTG_ID high usually through a pull-up resistor. The pull-up resistor is limited at 1 KOhm and should be powered by the output from the I/O ready pin. In this mode of operation, the USB_ DEVICE_VBUS is used only by the BD935-INS to detect the presence of the host power connected. See the OTG reference design section above for additional recommendations for EMI, ESD protection, and layout considerations. BD935-INS GNSS Receiver Module User Guide 33

34 4 Electrical System Integration USB VBUS The integrator needs to control VBUS. When the BD935-INS is in device mode, VBUS is provided by the host device and the integrator should not provide any power. In host mode, VBUS comes from pin 5 of J1 and the integrator needs to route this to pin 1 of the USB device. BD935-INS GNSS Receiver Module User Guide 34

35 4 Electrical System Integration Ethernet The BD935-INS provides magnetics for Ethernet so the integrator only needs to route the transmit/receive traces differentially to the Ethernet connector and terminate the spare lines. Recommended electrical specifications for the antenna The receiver has been designed to support a wide variety of GPS antenna elements. GNSS band coverage will be dictated by the bandwidth of the antenna chosen. In addition, the unit is capable of supporting antenna elements with a minimum LNA gain of +31 db. For optimum performance, the recommended antenna electrical specifications are outlined below: Feature Frequency VSWR Bandwidth Impedance Peak Gain Amplifier Gain Noise Figure Output VSWR Filtering DC Voltage DC Current Specification 1551 to 1614 MHz 1217 to 1257 MHz 1164 to 1214 MHz 2.0 max. 60 MHz 50 Ohm 4 dbic min. 31 db Note Required LNA gain does not account for antenna cable insertion loss. 1.5 db typical 1.5:1 typical -30 db (+/- 100 MHz) +3.3 to +5 V DC 300 ma max. ESD protection All pins on the 44-pin I/O connector are ESD protected. They are tested according to IEC level 3, 6 kv contact, 8 kv air discharge. BD935-INS GNSS Receiver Module User Guide 35

36 CHAPTER 5 Installation Unpacking and inspecting the shipment Installation guidelines Interface board evaluation kit Routing and connecting the antenna cable LED functionality and operation BD935-INS GNSS Receiver Module User Guide 36

37 5 Installation Unpacking and inspecting the shipment Visually inspect the shipping cartons for any signs of damage or mishandling before unpacking the receiver. Immediately report any damage to the shipping carrier. Shipment carton contents The shipment will include one or more cartons depending on the number of optional accessories ordered. Open the shipping cartons and make sure that all of the components indicated on the bill of lading are present. Reporting shipping problems Report any problems discovered after you unpack the shipping cartons to both Trimble Customer Support and the shipping carrier. Installation guidelines The receiver module is shipped in an unsoldered form along with the I/O evaluation board (if ordered). The I/O evaluation board has mounting slots to accommodate the GNSS module. For more information, refer to the drawings of the receiver. Considering environmental conditions Install the receiver in a location situated in a dry environment. Avoid exposure to extreme environmental conditions. This includes: Water or excessive moisture Excessive heat greater than 80 C (176 F) Excessive cold less than 40 C ( 40 F) Corrosive fluids and gases Avoiding these conditions improves the receiver s performance and long-term product reliability. Supported antennas The receiver tracks multiple GNSS frequencies; the Trimble Zephyr II antenna supports these frequencies. Other antennas may be used with the receiver. However, ensure that the antenna you choose supports the frequencies you need to track. For the BD930, BD930-UHF, BD935-INS receivers, the minimum required LNA gain is 31.0 db. BD935-INS GNSS Receiver Module User Guide 37

38 5 Installation Mounting the antennas Choosing the correct location for the antenna is critical for a high quality installation. Poor or incorrect placement of the antenna can influence accuracy and reliability and may result in damage during normal operation. Follow these guidelines to select the antenna location: If the application is mobile, place the antenna on a flat surface along the centerline of the vehicle. Choose an area with clear view to the sky above metallic objects. Avoid areas with high vibration, excessive heat, electrical interference, and strong magnetic fields. Avoid mounting the antenna close to stays, electrical cables, metal masts, and other antennas. Avoid mounting the antenna near transmitting antennas, radar arrays, or satellite communication equipment. Sources of electrical interference Avoid the following sources of electrical and magnetic noise: Gasoline engines (spark plugs) Television and computer monitors Alternators and generators Electric motors Propeller shafts Equipment with DC-to-AC converters Fluorescent lights Switching power supplies BD935-INS GNSS Receiver Module User Guide 38

39 5 Installation Interface board evaluation kit An evaluation kit is available for testing the receiver. This includes an I/O board that gives access to the following: Power input connector Power ON/OFF switch Three serial ports through DB9 connectors Ethernet through an RJ45 connector USB port through USB Type A and B receptacles Two pairs (Event and Ground) of pins for Event 1 and 2 respectively. One pair of pins (PPS and GND) for the 1 PPS Output Four LEDs to indicate satellite tracking, receipt of corrections, radio status, and power. The following figure shows a typical I/O board setup: ❶ BD935-INS receiver ❷ I/O board ❸ Zephyr antenna The computer connection provides a means to set up and configure the receiver. BD935-INS GNSS Receiver Module User Guide 39

40 5 Installation Routing and connecting the antenna cable 1. After mounting the antenna, route the antenna cable from the GPS antenna to the receiver. Avoid the following hazards when routing the antenna cable: Sharp ends or kinks in the cable Hot surfaces (such as exhaust manifolds or stacks) Rotating or reciprocating equipment Sharp or abrasive surfaces Door and window jams Corrosive fluids or gases 2. After routing the cable, connect it to the receiver. Use tie-wraps to secure the cable at several points along the route. For example, to provide strain relief for the antenna cable connection, use a tie-wrap to secure the cable near the base of the antenna. Note When securing the cable, start at the antenna and work towards the receiver. 3. When the cable is secured, coil any slack. Secure the coil with a tie-wrap and tuck it in a safe place. BD935-INS GNSS Receiver Module User Guide 40

41 5 Installation LED functionality and operation The evaluation interface board comes with four LEDs to indicate satellite tracking, RTK receptions, IMU Navigation Status, and power. The initial boot-up sequence for a receiver lights all the three LEDs for about three seconds followed by a brief duration where all four LEDs are off. Thereafter, use the following table to confirm tracking of satellite signals or for basic troubleshooting. Power LED RTK Corrections LED SV Tracking LED Status On (continuous) Off Off The receiver is turned on, but not tracking satellites. On (continuous) Off Blinking at 1 Hz The receiver is tracking satellites, but no incoming RTK corrections are being received. On (continuous) Blinking at 1 Hz Blinking at 1 Hz The receiver is tracking satellites and receiving incoming RTK corrections. On (continuous) Off or blinking (receiving corrections) Blinking at 5 Hz for a short while Occurs after a power boot sequence when the receiver is tracking less than 5 satellites and searching for more satellites. On (continuous) Blinking at 1 Hz Off The receiver is receiving incoming RTK corrections, but not tracking satellites. On (continuous) Blinking at 5 Hz Blinking at 1 Hz The receiver is receiving Moving Base RTK corrections at 5 Hz. On (continuous) On (continuous) Blinking at 1 Hz The receiver is receiving Moving Base RTK corrections at 10 or 20 Hz (the RTK LED turns off for 100 ms if a correction is lost). On (continuous) On, blinking off briefly at 1 Hz Blinking at 1 Hz The receiver is in a base station mode, tracking satellites and transmitting RTK corrections. On (continuous) Blinking at 1 Hz On (continuous) The receiver is in Boot Monitor Mode. Use the WinFlash utility to reload application firmware onto the board. For more information, contact technical support. For information about the LED pattern for the IMU Navigation Status, see LED control lines, page 27. BD935-INS GNSS Receiver Module User Guide 41

42 CHAPTER 6 Reference Frames and Offset Measurements Reference frames and offset measurements overview IMU Body Frame definition Reference Body Frame definition Vehicle Body Frame Lever Arm definitions BD935-INS GNSS Receiver Module User Guide 42

43 6 Reference Frames and Offset Measurements Reference frames and offset measurements overview Once the BD935-INS and antenna are installed on the vehicle, the relative position and orientation of the board with respect to the vehicle and GNSS antenna must be entered. Two types of measurements are required: 1. Lever arms vector displacement between two body frames. 2. Mounting angles differences in orientation between two body frames. CAUTION - The correct measurements must be entered into the receiver for the system to correctly function. Failure to do so will result in degraded performance. New values must be entered either after the location of any component has changed or the first time the system is turned on after a new installation. Accurate measurements of the mounting parameters are necessary to ensure optimum performance of the system. Four sets of parameters are required to be measured and input into the system before the BD935-INS can operate. These parameters are as follows: Reference frame origin to IMU lever arm Reference frame origin to GNSS antenna lever arm IMU body frame with respect to reference body frame mounting angles Reference frame with respect to vehicle body frame mounting angles The accuracy requirements of these measurements are important. Mounting angles (known as misalignment or boresight angles) are measured to the accuracy expected from the BD935-INS system. For example, if vehicle roll has a required accuracy of 0.1 degrees, then the IMU body frame with respect to the reference body frame mounting angles must be measured and entered to better than 0.1 degrees accuracy. If the accuracy of the measurements does not meet these requirements, a constant angular offset will be present in the output and the error may manifest itself as a lever arm error. BD935-INS GNSS Receiver Module User Guide 43

44 6 Reference Frames and Offset Measurements IMU Body Frame definition The IMU Body frame is the right-hand orthogonal coordinate system that is measured by the inertial sensors on the BD935-INS. The origin of the IMU body frame is at the center of the board. (see Figure 17). Reference Body Frame definition The Reference Body frame is defined as the right-hand orthogonal coordinate system with its origin at the center of a location to which a related sensor is referenced. For example, using the BD935-INS mounted on a scanner, the origin of the reference body frame is at the origin of the scanner measurements, and the x, y, and z are the orthogonal axis of the scanner frame. All measurements output by the BD935-INS system are at the Reference frame origin and aligned to the Reference frame axis. Figure 17: IMU Body Frame Definition BD935-INS GNSS Receiver Module User Guide 44

45 6 Reference Frames and Offset Measurements Vehicle Body Frame The Vehicle Body Frame is defined as the right-hand orthogonal coordinate system with its origin at the vehicle s centerline. Its three axis are referenced to the vehicle s vertical and horizontal planes where the: X-axis is parallel to the horizontal plane and extends towards the nose (or direction of travel) called the vehicle longitudinal axis; any rotation about this axis is called roll. Y-axis is parallel to the horizontal plane and extends towards the starboard (right) wing called the vehicle lateral axis (wing tip through wing tip); any rotation about this axis is called pitch. Z-axis is parallel to the vertical plane and extends down called the vehicle vertical axis (vertically through the center of gravity when the airborne vehicle is in level flight); any rotation about this axis is called yaw. BD935-INS GNSS Receiver Module User Guide 45

46 6 Reference Frames and Offset Measurements Lever Arm definitions Reference to IMU Lever Arm The Reference to IMU Lever Arm is a three-dimensional vector defining the displacement of the IMU Body Frame (that is the center of the board) origin from the Reference Body Frame origin. This displacement is measured in the Reference Body frame. The displacement is measured as follows: X component Y component Z component The distance from the Reference Body Frame origin along the x axis of the Reference Body Frame to the center of the BD935-INS board. A positive value implies the board is forward of the Reference Body Frame origin. The distance from the Reference Body Frame origin along the y axis of the Vehicle Body Frame to center of the BD935-INS board. A positive value implies the board is to the right of the Reference Body Frame origin. The distance from the Reference Body Frame origin along the z axis of the Reference Body Frame to the center of the BD935-INS board. A positive value implies the board is below the Reference Body Frame origin. Reference to GNSS Lever Arm The Reference to GNSS Lever Arm is the three-dimensional vector defining the displacement of the GNSS Antenna Phase Center (APC) from the origin of the Reference Body Frame. This displacement is measured in the Vehicle Body Frame, not the Reference Body Frame. The displacement is measured as follows: X component Y component Z component The distance from the Reference Body Frame origin along the x axis of the Vehicle Body Frame to the GNSS APC. A positive value implies the GNSS antenna is forward of the Reference Body Frame origin. The distance from the Reference Body Frame origin along the y axis of the Vehicle Body Frame to the GNSS APC. A positive value implies the GNSS antenna is to the right of the Reference Body Frame origin. The distance from the Reference Body Frame origin along the z axis of the Vehicle Body Frame to the GNSS APC. A negative value implies the GNSS antenna is above the Reference Body Frame origin. Mounting Angles The Mounting angles are defined as the physical angular offsets of one body frame with respect to a second body frame (Figure 1). BD935-INS GNSS Receiver Module User Guide 46

47 6 Reference Frames and Offset Measurements These angles define the Tate-Bryant sequence of rotations that bring the first body frame into alignment with the second. For example, when defining body frame A with respect to B, the mounting angles would be the sequence of rotations of body frame B to bring it into alignment with body frame A. The orientation angles follow the sequence of rotation given as follows: right-hand rotation of θz about the z-axis of body frame B, followed by a rotation of θy about the once rotated y-axis, followed by a rotation of θx about the twice-rotated x-axis. Refer to the Tate-Bryant Sequence description. Make note of all measured mounting angles for later input into the BD935-INS and store these measurements in a secure place for future reference. Figure 1: BD935-INS Reference and IMU Body Frame Tate-Bryant Sequence Locate the X1, Y1, and Z1 axis and the XY, YZ, ZX planes of the IMU reference frame. Locate the user frame axis X2, Y2, Z2 (Figure 2). To bring the IMU into alignment with the user frame, rotate the user frame about its Z2 axis until the Y2 axis is in the YZ plane of the IMU (Figure 3). Rotate the user frame about its Y2 axis (already once rotated), until the X2 axis direction is parallel to the X1 axis direction. Rotate the user frame about its X2 axis (already twice rotated) until the Y2 axis is parallel to the Y1 axis. BD935-INS GNSS Receiver Module User Guide 47

48 6 Reference Frames and Offset Measurements Figure 2: Tate-Bryant Planes and Axis Figure 3: Tate-Bryant Rotations Diagram Yaw is the angle θ1 from the first rotation. Pitch is the angle θ2 from the second rotation and Roll is the third rotation angle θ3, shown in the diagram above. IMU wrt Reference Mounting Angles Figure 1 shows the BD935-INS Board (IMU Body Frame) and the Reference Body Frames in different orientations. The sequence of rotations to bring the Reference Body Frame into alignment with the IMU Body Frame will require measurement. BD935-INS GNSS Receiver Module User Guide 48

49 6 Reference Frames and Offset Measurements Reference wrt Vehicle Mounting Angles If the axis of the Reference Body Frame and the Vehicle Body Frames (i.e., aircraft) do not align, then the Reference Body Frame must be defined with respect to the Vehicle Body Frame by entering Vehicle to Reference Mounting angles. These angles follow the same sequence of rotation as described above. For example, if the x axis of the Reference Body Frame is pointing to the right wing of the aircraft, the Vehicle to Reference Body Frame Mounting Angles would be (0,0,90). Receiver configuration The receiver is configured for INS/GNSS operation using the on-board web server in the receiver. Information on how to connect to the web server and specific INS/GNSS settings are detailed in the Configuring the Receiver section of the online help. Here you will also find details of how to configure the receiver using binary commands. BD935-INS GNSS Receiver Module User Guide 49

50 CHAPTER 7 Troubleshooting Receiver Issues This section describes some possible receiver issues, possible causes, and how to solve them. Please read this section before you contact Technical Support. Issue Possible cause Solution The receiver does not turn on. The base station receiver is not broadcasting. Rover receiver is not receiving radio. External power is too low. Port settings between reference receiver and radio are incorrect. Faulty cable between receiver and radio. No power to radio. The base station receiver is not broadcasting. Incorrect over air baud rates between reference and rover. Incorrect port settings between roving external radio and receiver. Check that the input voltage is within limits. Check the settings on the radio and the receiver. Try a different cable. Examine the ports for missing pins. Use a multimeter to check pinouts. If the radio has its own power supply, check the charge and connections. Examine the ports for missing pins. Use a multimeter to check pinouts. See the issue "The base station receiver is not broadcasting" above. Connect to the rover receiver radio, and make sure that it has the same setting as the reference receiver. If the radio is receiving data and the receiver is not getting radio communications, check that the port settings are correct. The receiver is The GPS antenna cable is Make sure that the GPS antenna cable is tightly BD935-INS GNSS Receiver Module User Guide 50

51 7 Troubleshooting Receiver Issues Issue Possible cause Solution not receiving satellite signals. loose. The cable is damaged. The GPS antenna is not in clear line of sight to the sky. seated in the GPS antenna connection on the GPS antenna. Check the cable for any signs of damage. A damaged cable can inhibit signal detection from the antenna at the receiver. Make sure that the GPS antenna is located with a clear view of the sky. Restart the receiver as a last resort (turn off and then turn it on again). BD935-INS GNSS Receiver Module User Guide 51

52 Glossary 1PPS almanac base station BeiDou BINEX Pulse-per-second. Used in hardware timing. A pulse is generated in conjunction with a time stamp. This defines the instant when the time stamp is applicable. A file that contains orbit information on all the satellites, clock corrections, and atmospheric delay parameters. The almanac is transmitted by a GNSS satellite to a GNSS receiver, where it facilitates rapid acquisition of GNSS signals when you start collecting data, or when you have lost track of satellites and are trying to regain GNSS signals. The orbit information is a subset of the ephemeris/ephemerides data. Also called reference station. In construction, a base station is a receiver placed at a known point on a jobsite that tracks the same satellites as an RTK rover, and provides a real-time differential correction message stream through radio to the rover, to obtain centimeter level positions on a continuous real-time basis. A base station can also be a part of a virtual reference station network, or a location at which GNSS observations are collected over a period of time, for subsequent postprocessing to obtain the most accurate position for the location. The BeiDou Navigation Satellite System (also known as BDS ) is a Chinese satellite navigation system. The first BeiDou system (known as BeiDou-1), consists of four satellites and has limited coverage and applications. It has been offering navigation services mainly for customers in China and from neighboring regions since The second generation of the system (known as BeiDou-2) consists of satellites in a combination of geostationary, inclined geosynchronous, and medium earth orbit configurations. It became operational with coverage of China in December However, the complete Interface Control Document (which specifies the satellite messages) was not released until December BeiDou-2 is a regional navigation service which offers services to customers in the Asia-Pacific region. A third generation of the BeiDou system is planned, which will expand coverage globally. This generation is currently scheduled to be completed by BInary EXchange format. BINEX is an operational binary format standard for GPS/GLONASS/SBAS research purposes. It is designed to grow and allow encapsulation of all (or most) of the information currently allowed for in a range of other formats. BD935-INS GNSS Receiver Module User Guide 52