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Vectornav VN-100 User Manual

Manual is about: Embedded Navigation Solutions

Summary of VN-100

  • Page 1

    Um001 1 firmware v2.1.0.0 document revision 2.22 vn-100 user manual embedded navigation solutions.

  • Page 2

    2 um001 document information title vn-100 user manual subtitle inertial navigation modules document type user manual document number um001 v2.22 document status released vectornav technical documentation in addition to our product-specific technical data sheets, the following manuals are available t...

  • Page 3

    Um001 3 table of contents 1 introduction 5 1.1 product description 5 1.2 factory calibration 5 1.3 operation overview 5 1.4 packaging options 6 1.5 vn-100 product codes 8 2 specifications 9 2.1 vn-100 surface-mount sensor (smd) electrical 9 2.2 vn-100 rugged electrical 12 2.3 vn-100 surface-mount se...

  • Page 4

    4 um001 5.2 configuration registers 57 5.3 status registers 75 5.4 factory defaults 76 5.5 command prompt 77 6 imu subsystem 79 6.1 imu measurement registers 79 6.2 imu configuration registers 81 6.3 factory defaults 88 6.4 command prompt 89 7 attitude subsystem 91 7.1 commands 91 7.2 measurement re...

  • Page 5: 1  Introduction

    Um001 5 1 introduction 1.1 product description the vn-100 is a miniature surface mount high-performance inertial measurement unit (imu) and attitude heading reference system (ahrs). Incorporating the latest solid-state mems sensor technology, the vn- 100 combines a set of 3-axis accelerometers, 3-ax...

  • Page 6: Packaging Options

    6 um001 three-axis accelerometer are compared to the expected magnitude and direction of gravity in determining the pitch and roll angles while measurements from the three-axis magnetometer are compared to the expected magnitude and direction of earth’s background magnetic field in determining the h...

  • Page 7

    Um001 7 1.4.1 surface-mount package for embedded applications, the vn-100 is available in a miniature surface-mount package. Features  small size: 22 x 24 x 3 mm  single power supply: 3.2 to 5.5 v  communication interface: serial ttl & spi  low power requirement: 1.4.2 rugged package the vn-100 ...

  • Page 8: Vn-100 Product Codes

    8 um001  board size: 76 x 76 x 14 mm 1.4.4 vn-100 rugged development kit the vn-100 rugged development kit includes the vn-100 rugged sensor along with all of the necessary cabling required for operation. Two cables are provided in each development kit: one custom cable for rs-232 communication and...

  • Page 9: 2  Specifications

    Um001 9 2 specifications 2.1 vn-100 surface-mount sensor (smd) electrical pin assignments (top down view).

  • Page 10

    10 um001 vn-100 smd pin assignments pin pin name type description 1 gnd supply ground. 2 gnd supply ground. 3 gnd supply ground. 4 gnd supply ground. 5 tx2 output serial uart #2 data output. (sensor) 6 rx2 input serial uart #2 data input. (sensor) 7 restore input normally used to zero (tare) the att...

  • Page 11

    Um001 11 2.1.1 vn-100 smd power supply the minimum operating supply voltage is 3.2v and the absolute maximum is 5.5v. 2.1.2 vn-100 smd serial (uart) interface the serial interface on the vn-100 operates with 3v ttl logic. Serial i/o specifications specification min typical max input low level voltag...

  • Page 12: Vn-100 Rugged Electrical

    12 um001 2.2 vn-100 rugged electrical vn-100 rugged pin assignments pin pin name description 1 vcc +4.5v to +5.5v 2 tx1 rs-232 voltage levels data output from the sensor. (serial uart #1) 3 rx1 rs-232 voltage levels data input to the sensor. (serial uart #1) 4 sync_out output signal used for synchro...

  • Page 13

    Um001 13 2.2.1 vn-100 rugged power supply the power supply input for the vn-100 rugged is 4.5 to 5.5 v dc. 2.2.2 vn-100 rugged serial uart interface serial i/o specifications specification min typical max input low level voltage -25 v input high level voltage 25 v output low voltage -5.0 v -5.4 v ou...

  • Page 14: Vn-100 Rugged Dimensions

    14 um001 2.3 vn-100 surface-mount sensor (smd) dimensions * measurements are in inches 2.4 vn-100 rugged dimensions.

  • Page 15: Absolute Maximum Ratings

    Um001 15 2.4.1 rugged connector type the main connector used on the vn-100 rugged is a 10-pin harwin m80-5001042. The mating connector used on the cable assemblies provided by vectornav for use with the vn-100 rugged is a harwin m80- 4861005. 2.5 absolute maximum ratings smd absolute maximum ratings...

  • Page 16

    16 um001 2.6.2 north-east-down frame the vn-100 velocity estimates can be output in the north-east-down (ned) coordinate frame defined as follows (n x , n y , n z ):  right-handed, cartesian, non-inertial, geodetic frame with origin located at the surface of earth (wgs84 ellipsoid);  positive x-ax...

  • Page 17: Imu Subsystem

    Um001 17 3 vn-100 software architecture the software architecture internal to the vn-100 includes four separate subsystems. These subsystems are the imu, the navstate, the navfilter, and the communication interface. The high-level functions performed by these subsystems are outlined below. This chap...

  • Page 18

    18 um001 3.1.1 magnetometer magnetometer imu measurements 3.1.2 accelerometer accelerometer imu measurements 3.1.3 gyro gyro imu measurements 3.1.4 raw imu measurements the raw imu measurements are collected from the internal mems at the highest rate available for each individual sensor. For the gyr...

  • Page 19

    Um001 19 3.1.6 user calibration the vn-100 provides the user with the ability to apply a separate user calibration to remove additional bias, scale factor, and axis misalignments. The user calibration is applied after the factory calibration, and can be used to optionally fine tune the calibration f...

  • Page 20: Navstate Subsystem

    20 um001 3.2 navstate subsystem the navstate subsystem generates a continuous reliable stream of low-latency, low-jitter state outputs at a rate fixed to the imu sample rate. The state outputs include any output such as attitude, position, and velocity, which are not directly measureable by the imu ...

  • Page 21

    Um001 21 velocity, as well as the time varying gyro, accelerometer, and barometric pressure sensor biases. The output of the ins kalman filter is passed to the navstate, allowing for the attitude, position, and velocity to be made available at the higher fixed rate of the navstate. 3.3.2 vector proc...

  • Page 22: Vector Processing Engine

    22 um001 3.3.6 world gravity model the world gravity model (wgm) is a large spatial-scale representation of the earth’s gravity potential as a function of position on the globe. The internal model used on the vn-100 is consistent with the earth gravity model (egm96), which consist of a spherical-har...

  • Page 23

    Um001 23 absolute heading mode in absolute heading mode the vpe will assume that the principal long-term dc component of the measured magnetic field is directly related to the earth’s magnetic field. As such only short term magnetic disturbances will be tuned out. This mode is ideal for applications...

  • Page 24

    24 um001 which minimizes the effect of gyro drift while maintaining a stable and accurate pitch and roll solution. Since the relative heading mode assumes that other magnetic disturbances can be present which are indistinguishable from the earth's field, relative heading mode cannot always ensure th...

  • Page 25

    Um001 25 indoor heading mode disadvantages  measurement repeatability may be worse than relative mode during periods when the vpe corrects for known errors in absolute heading. Overview of heading modes a summary of the different types of disturbances handled by each magnetic mode is summarized in ...

  • Page 26: Communication Interface

    26 um001  the minimum value of zero turns off all adaptive tuning.  the maximum value of 10 applies several times the estimated level of uncertainty. Adaptive filtering gain the adaptive filtering stage of the vpe monitors both the magnetic and acceleration measurements to determine if large ampli...

  • Page 27: Communication Protocol

    Um001 27 3.6 communication protocol the vn-100 utilizes a simple command based communication protocol for the serial interface. An ascii protocol is used for command and register polling, and an optional binary interface is provided for streaming high speed real-time sensor measurements. 3.6.1 seria...

  • Page 28

    28 um001 error codes error name code description hard fault 1 if this error occurs, then the firmware on the vn-100 has experienced a hard fault exception. To recover from this error the processor will force a restart, and a discontinuity will occur in the serial output. The processor will restart w...

  • Page 29: Checksum / Crc

    Um001 29 3.8 checksum / crc the serial interface provides the option for either an 8-bit checksum or a 16-bit crc. In the event neither the checksum nor the crc is needed, both can be turned off by the user. Refer to the communication protocol control register for details on disabling the checksum/c...

  • Page 30

    30 um001 3.8.3 16-bit crc for cases where the 8-bit checksum doesn't provide enough error detection, a full 16-bit crc is available. The vn-100 uses the crc16-ccitt algorithm. The resultant crc is a 16-bit number and is represented in the command as four hexadecimal characters. The c function snippe...

  • Page 31: Available Output Types

    Um001 31 4 user configurable binary output messages the vn-100 supports 3 separate user configurable binary output messages available on the serial interface. Each message can be configured by the user to contain any of the available output measurement types from the imu, navstate, or navfilter subs...

  • Page 32

    32 um001 (if present) selects groups 8-14, and so on. The sequence of group selection bytes will always end with a byte whose extension bit is not set. Name bit offset description output group 1 0 common group output group 2 1 time group output group 3 2 imu group output group 5 4 attitude group out...

  • Page 33

    Um001 33 4.2.3 setup the configuration register once you have determined the desired outputs for your output messages, you will need to configure the user output message configuration registers (register 75 – 77). These registers are described in detail under the binary output register 1-3 in the sy...

  • Page 34

    34 um001 4.2.4 example case 1 – selecting outputs from only the common group for many applications you might be able to get by with only the output types available in the common group. For these situations the configuration of the output message is simple. Suppose only the following information show...

  • Page 35

    Um001 35 4 magned also assume that you want the message to stream at 50 hz over serial port 1. To configure this output message you would send the following command to the vn-100. $vnwrg,75,1,16,15,0001,000c,0014*xx now let’s dissect this command to see what is actually being set: field value descri...

  • Page 36

    36 um001 4.3 serial output message format the binary output message packets on the serial interface consist of a simple message header, payload, and a 16-bit crc. An example packet is shown below for reference. The header is variable length depending upon the number of groups active in the message. ...

  • Page 37

    Um001 37 4.3.3 group fields the group field parameter consists of a series of one or more 16-bit words per selected output group which are used to identify the selected output fields for that group. The first series of one or more words corresponds to the fields for the first selected group, followe...

  • Page 38

    38 um001 4.3.6 payload length when parsing the packet you will need to know the length of the payload (in bytes) in order to know where the packet ends in the data stream. In order to reduce the overhead of the packet header length, the length of the payload is not included in the header. Instead it...

  • Page 39

    Um001 39 example code // 2d array to determine the payload length for a binary output packet. The first // index of the array is the group number, and the second index // is the group field index. Both indices are assumed to be zero based. Const unsigned char grouplen[7][16] = { {8, 8, 8, 12, 16, 12...

  • Page 40

    40 um001 example case 2 for the second example case we will assume that both binary group 1 and 3 are active. In binary group 1, the ypr output is selected, and in binary group 3, the temp output is selected. Header field sync group group 1 fields group 3 fields byte offset 0 1 2 3 4 5 byte value (h...

  • Page 41

    Um001 41 4.4 binary group 1 – common outputs binary group 1 contains a wide assortment of commonly used data required for most applications. All of the outputs found in group 1 are also present in the other groups. In this sense, group 1 is a subset of commonly used outputs from the other groups. Th...

  • Page 42

    42 um001 4.4.3 yawpitchroll the estimated attitude yaw, pitch, and roll angles measured in degrees. The attitude is given as a 3,2,1 euler angle sequence describing the body frame with respect to the local north east down (ned) frame. This field is equivalent to the yawpitchroll field in group 5. Ya...

  • Page 43

    Um001 43 rate and acceleration measurements straight from the imu. The measurements have not been corrected for bias offset by the onboard kalman filter. These are equivalent to the uncompaccel and uncompgyro fields in group 3. Imu accel[0] accel[1] accel[2] rate[0] rate[1] rate[2] byte offset 0 1 2...

  • Page 44

    44 um001 4.4.10 syncincnt the number of syncin trigger events that have occurred. This field is equivalent to the syncincnt field in group 2. Syncincnt byte offset 0 1 2 3 type u32.

  • Page 45

    Um001 45 4.5 binary group 2 – time outputs binary group 2 provides all timing and event counter related outputs. Some of these outputs (such as the timegps, timepps, and timeutc), require either that the internal gps to be enabled, or an external gps must be present. Binary group 2 name bit offset d...

  • Page 46

    46 um001 4.6 binary group 3 – imu outputs binary group 3 provides all outputs which are dependent upon the measurements collected from the onboard imu, or an external imu (if enabled). Binary group 3 name bit offset description imustatus 0 reserved for future use. Uncompmag 1 uncompensated magnetic ...

  • Page 47

    Um001 47 4.6.4 uncompgyro the imu angular rate measured in units of rad/s, given in the body frame. This measurement is compensated by the static calibration (individual factory calibration stored in flash), however it is not compensated by any dynamic calibration such as the bias compensation from ...

  • Page 48

    48 um001 4.6.8 deltav the delta velocity (dvel) is the delta velocity incurred due to motion, since the last time the values were output by the device. The delta velocities are calculated based upon the onboard conning and sculling integration performed onboard the sensor at the imu sampling rate (n...

  • Page 49

    Um001 49 4.7 binary group 5 – attitude outputs binary group 5 provides all estimated outputs which are dependent upon the estimated attitude solution. The attitude will be derived from either the ahrs or the ins, depending upon which filter is currently active and tracking. All of the fields in this...

  • Page 50

    50 um001 table 1 - attitudequality field value description 0 excellent 1 good 2 bad 3 not tracking 4.7.2 yawpitchroll the estimated attitude yaw, pitch, and roll angles measured in degrees. The attitude is given as a 3,2,1 euler angle sequence describing the body frame with respect to the local nort...

  • Page 51

    Um001 51 stored in flash), and the dynamic calibration such as the user or onboard hard/soft iron compensation registers. Magned mag[0] mag[1] mag[2] byte offset 0 1 2 3 4 5 6 7 8 9 10 11 type float float float 4.7.6 accelned the estimated acceleration (with gravity) reported in m/s^2, given in the ...

  • Page 52

    52 um001 4.7.8 linearaccelned the estimated linear acceleration (without gravity) reported in m/s^2, and given in the north east down (ned) frame. This measurement is attitude dependent as the attitude solution is used to map the measurement from the body frame into the inertial (ned) frame. This ac...

  • Page 53: 5  System Module

    Um001 53 5 system module 5.1 commands 5.1.1 read register command this command allows the user to read any of the registers on the vn-100. The only required parameter is the id of the register to be read. The first parameter of the response will contain the same register id followed by a variable nu...

  • Page 54

    54 um001 5.1.3 write settings command this command will write the current register settings into non-volatile memory. Once the settings are stored in non-volatile (flash) memory, the vn-100 module can be power cycled or reset, and the register will be reloaded from non-volatile memory. Example write...

  • Page 55

    Um001 55 5.1.6 firmware update command this command is used to enter the boot loader for performing firmware updates. Upon receiving this command on serial port 1, the vn-100 will enter into firmware reprogramming mode. The easiest method of updating firmware is to use one of the vectornav firmware ...

  • Page 56

    56 um001 5.1.8 asynchronous output pause command this command allows the user to temporarily pause the asynchronous outputs on the given serial port. When paused, both the ascii and the 3 binary asynchronous output messages will temporarily stop outputting from the device on the serial port for whic...

  • Page 57: Configuration Registers

    Um001 57 5.2 configuration registers 5.2.1 user tag register user tag register id : 0 access : read / write comment : user assigned tag register. Any values can be assigned to this register. They will be stored to flash upon issuing a write settings command. Size (bytes): 20 example response: $vnrrg...

  • Page 58

    58 um001 5.2.2 model number register model number register id : 1 access : read only comment : model number size (bytes): 24 example response: $vnrrg,01,vn-310*58 offset name format unit description 0 product name char - product name. Max 24 characters..

  • Page 59

    Um001 59 5.2.3 hardware revision register register id : 2 access : read only comment : hardware revision. Size (bytes): 4 example response: $vnrrg,02,1*6c offset name format unit description 0 revision uint32 - hardware revision..

  • Page 60

    60 um001 5.2.4 serial number register serial number register id : 3 access : read only comment : serial number size (bytes): 4 example response: $vnrrg,03,0100011981*5d offset name format unit description 0 serialnum uint32 - serial number (32-bit unsigned integer).

  • Page 61

    Um001 61 5.2.5 firmware version register firmware version register register id : 4 access : read only comment : firmware version. Size (bytes): 4 example response: $vnrrg,04,0.4.0.0*71 offset name format unit description 0 major version uint8 - major release version of firmware. 1 minor version uint...

  • Page 62

    62 um001 5.2.6 serial baud rate register serial baud rate register id : 5 access : read / write comment : serial baud rate. Size (bytes): 4 example command: $vnwrg,05,115200*58 offset name format unit description 0 baud rate uint32 - serial baud rate. 4 serial port uint8 - optional. The serial port ...

  • Page 63

    Um001 63 5.2.7 async data output type register asynchronous data output type register id : 6 access : read / write comment : asynchronous data output type. Size (bytes): 4 example command: $vnwrg,06,0*6c offset name format unit description 0 ador uint32 - output register. 4 serial port uint8 - optio...

  • Page 64

    64 um001 asynchronous solution output settings setting asynchronous solution output type header 0 asynchronous output turned off n/a 1 yaw, pitch, roll vnypr 2 quaternion vnqtn 8 quaternion, magnetic, acceleration and angular rates vnqmr 9 directional cosine orientation matrix vndcm 10 magnetic meas...

  • Page 65

    Um001 65 5.2.8 async data output frequency register asynchronous data output frequency register id : 7 access : read / write comment : asynchronous data output frequency. Size (bytes): 4 example command: $vnwrg,07,40*59 offset name format unit description 0 adof uint32 hz output frequency. 4 serial ...

  • Page 66

    66 um001 5.2.9 synchronization control synchronization control register id : 32 access : read / write comment : contains parameters which allow the timing of the vn-100 to be synchronized with external devices. Size (bytes): 20 example response: $vnrrg,32,3,0,0,0,6,1,0,100000000,0*6b offset name for...

  • Page 67

    Um001 67 syncinedge the syncinedge register controls the type of edge the signal is set to trigger on. The factory default state is to trigger on a rising edge. Syncinedge mode value description 0 trigger on rising edge 1 trigger on falling edge syncinskipfactor the syncinskipfactor defines how many...

  • Page 68

    68 um001 5.2.10 communication protocol control communication protocol control register id : 30 access : read / write comment : contains parameters that controls the communication protocol used by the sensor. Size (bytes): 7 example response: $vnrrg,30,0,0,0,0,1,0,1*6c offset name format unit descrip...

  • Page 69

    Um001 69 serial count the serialcount field provides a means of appending a time or counter to the end of all asynchronous communication messages transmitted on the serial interface. The values for each of these counters come directly from the synchronization status register in the system subsystem....

  • Page 70

    70 um001 spicount the spicount field provides a means of appending a time or counter to the end of all spi packets. The values for each of these counters come directly from the synchronization status register. Spicount field mode value description none 0 off syncin_count 1 syncin counter syncin_time...

  • Page 71

    Um001 71 errormode this field controls the type of action taken by the vn-100 when an error event occurs. If the send error mode is enabled then a message similar to the one shown below will be sent on the serial bus when an error event occurs. $vnerr,03*72 regardless of the state of the errormode, ...

  • Page 72

    72 um001 5.2.11 binary output register 1 binary output register 1 register id : 75 access : read / write comment : this register allows the user to construct a custom binary output message that contains a collection of desired estimated states and sensor measurements. Size (bytes): 6-22 example resp...

  • Page 73

    Um001 73 5.2.12 binary output register 2 binary output register 2 register id : 76 access : read / write comment : this register allows the user to construct a custom binary output message that contains a collection of desired estimated states and sensor measurements. Size (bytes): 6-22 example resp...

  • Page 74

    74 um001 5.2.13 binary output register 3 binary output register 3 register id : 77 access : read / write comment : this register allows the user to construct a custom binary output message that contains a collection of desired estimated states and sensor measurements. Size (bytes): 6-22 example resp...

  • Page 75: Status Registers

    Um001 75 5.3 status registers 5.3.1 synchronization status synchronization status register id : 33 access : read / write comment : contains status parameters that pertaining to the communication synchronization features. Size (bytes): 12 example response: $vnrrg,33,2552498,0,0*6a offset name format ...

  • Page 76: Factory Defaults

    76 um001 5.4 factory defaults settings name default factory value user tag null (empty string) serial baud rate 115200 async data output frequency 40 hz async data output type ins_lla synchronization control 3,0,0,0,6,1,0,100000000,0 communication protocol control 0,0,0,0,1,0,1 binary output registe...

  • Page 77: Command Prompt

    Um001 77 5.5 command prompt the command prompt provides a fast and simple means of configuring and monitoring the status of the sensor by typing commands to the unit using the serial port. 5.5.1 list available commands commands for the system subsystem can be accessed by typing in ‘system’ at the co...

  • Page 78

    78 um001 current serial 1 tx bandwidth usage : 00.0 current serial 2 tx bandwidth usage : 49.3 max serial 1 tx bandwidth usage : 49.3 max serial 2 tx bandwidth usage : 50.5 min serial 1 tx bandwidth usage : 00.0 min serial 2 tx bandwidth usage : 48.1 -------------------------------------------------...

  • Page 79: 6  Imu Subsystem

    Um001 79 6 imu subsystem 6.1 imu measurement registers 6.1.1 imu measurements this register provides direct access to the calibrated magnetometer, accelerometer, gyro, barometric pressure, and temperature measurements available from the onboard imu. Imu measurements register id : 54 async header : i...

  • Page 80

    80 um001 6.1.2 delta theta and delta velocity delta theta and delta velocity register id : 80 async header: dtv access : read comment : this register contains the output values of the onboard coning and sculling algorithm. Size (bytes): 28 example response: $vnrrg,80,+0.665016,-000.119,-000.409,-000...

  • Page 81

    Um001 81 6.2 imu configuration registers 6.2.1 magnetometer compensation magnetometer compensation register id : 23 access: read / write comment : allows the magnetometer to be compensated for hard/soft iron effects. Size (bytes): 48 example command: $vnrrg,23,1,0,0,0,1,0,0,0,1,0,0,0*73 offset name ...

  • Page 82

    82 um001 6.2.2 acceleration compensation accelerometer compensation register id : 25 access : read / write comment : allows the accelerometer to be further compensated for scale factor, misalignment, and bias errors. Size (bytes): 48 example command: $vnrrg,25,1,0,0,0,1,0,0,0,1,0,0,0*75 offset name ...

  • Page 83

    Um001 83 6.2.3 gyro compensation gyro compensation register id : 84 access : read / write comment : allows the gyro to be further compensated for scale factor, misalignment, and bias errors. Size (bytes): 48 example command: $vnrrg,84,1,0,0,0,1,0,0,0,1,0,0,0*7e offset name format unit description 0 ...

  • Page 84

    84 um001 6.2.4 reference frame rotation reference frame rotation register id : 26 access : read / write comment : allows the measurements of the vn-100 to be rotated into a different reference frame. Size (bytes): 36 example response: $vnrrg,26,1,0,0,0,1,0,0,0,1*6a offset name format unit descriptio...

  • Page 85

    Um001 85 6.2.5 imu filtering configuration imu filtering configuration register id : 85 access : read / write comment : controls the level of filtering performed on the raw imu measurements. Size (bytes): 15 example response: $vnrrg,85,0,5,5,5,0,0,3,3,3,0*78 offset name format unit description 0 mag...

  • Page 86

    86 um001 6.2.6 delta theta and delta velocity configuration delta theta and delta velocity configuration register id : 82 access : read / write comment : this register contains configuration options for the internal coning/sculling calculations size (bytes): 6 example response: $vnrrg,82,0,0,0,0,0*6...

  • Page 87

    Um001 87 accelcompensation the accelcompensation register setting selects the compensation to be applied to the acceleration measurements before integration. If bias compensation is selected, the onboard kalman filter’s real-time estimate of the accel biases will be used to compensate the imu measur...

  • Page 88: Factory Defaults

    88 um001 6.3 factory defaults settings name default factory value magnetometer compensation 1,0,0,0,1,0,0,0,1,0,0,0 accelerometer compensation 1,0,0,0,1,0,0,0,1,0,0,0 gyro compensation 1,0,0,0,1,0,0,0,1,0,0,0 reference frame rotation 1,0,0,0,1,0,0,0,1 imu filtering configuration 0,4,4,4,0,0,3,3,3,0 ...

  • Page 89: Command Prompt

    Um001 89 6.4 command prompt the command prompt provides a fast and simple means of configuring and monitoring the status of the sensor by typing commands to the unit using the serial port. 6.4.1 list available commands commands for the system subsystem can be accessed by typing in ‘imu’ at the comma...

  • Page 90

    90 um001 6.4.3 imu meas imu meas ------------------------------ imu measurement ------------------------------- current sensor measurements: mag x : -000.866 [gauss] mag y : +001.016 [gauss] mag z : +002.365 [gauss] acel x : +004.178 [m/s] acel y : -000.637 [m/s] acel z : -008.927 [m/s] gyro x : -00...

  • Page 91: 7  Attitude Subsystem

    Um001 91 7 attitude subsystem 7.1 commands 7.1.1 known magnetic disturbance command this command is used to notify the vn-100 that a magnetic disturbance is present. When the vn-100 receives this command it will tune out the magnetometer and will pause the current hard/soft iron calibration if it is...

  • Page 92: Measurement Registers

    92 um001 uart command $vnsgb*xx uart response $vnsgb*xx spi command (8 bytes) 0c 00 00 00 (shown as hex) spi response (8 bytes) 00 0c 00 00 (shown as hex) 7.2 measurement registers 7.2.1 yaw pitch roll yaw, pitch, and roll register id : 8 async header : ypr access : read only comment : attitude solu...

  • Page 93

    Um001 93 7.2.2 attitude quaternion quaternion register id : 9 async header : qtn access : read only comment : attitude solution as a quaternion. Size (bytes): 16 example response: $vnrrg,9,-0.017386,-0.000303,+0.055490,+0.998308*4f offset name format unit description 0 quat[0] float - calculated att...

  • Page 94

    94 um001 7.2.3 yaw, pitch, roll, magnetic, acceleration, and angular rates yaw, pitch, roll, magnetic, acceleration, and angular rates register id : 27 async header : ymr access : read only comment : attitude solution, magnetic, acceleration, and compensated angular rates. Size (bytes): 48 example r...

  • Page 95

    Um001 95 7.2.4 quaternion, magnetic, acceleration and angular rates quaternion, magnetic, acceleration, and angular rates register id : 15 async header : qmr access : read only comment : attitude solution, magnetic, acceleration, and compensated angular rates. Size (bytes): 52 example response: $vnr...

  • Page 96

    96 um001 7.2.5 magnetic measurements magnetic measurements register id : 17 async header : mag access : read only comment : magnetometer measurements. Size (bytes): 12 example response: $vnrrg,17,+1.0647,-0.2498,+3.0628*66 offset name format unit description 0 magx float gauss compensated magnetomet...

  • Page 97

    Um001 97 7.2.6 acceleration measurements acceleration measurements register id : 18 async header : acc access : read only comment : acceleration measurements. Size (bytes): 12 example response: $vnrrg,18,+00.013,+00.354,-09.801*65 offset name format unit description 0 accelx float m/s 2 compensated ...

  • Page 98

    98 um001 7.2.7 angular rate measurements angular rate measurements register id : 19 async header : gyr access : read only comment : compensated angular rates. Size (bytes): 12 example response: $vnrrg,19,+0.002112,-0.000362,-0.000876*6c offset name format unit description 0 gyrox float rad/s compens...

  • Page 99

    Um001 99 7.2.8 magnetic, acceleration and angular rates magnetic, acceleration, and angular rates register id : 20 async header : mar access : read only comment : magnetic, acceleration, and compensated angular rates. Size (bytes): 36 example response: $vnrrg,20,+1.0684,-0.2578,+3.0649,-00.005,+00.3...

  • Page 100: Configuration Registers

    100 um001 8 hard/soft iron estimator subsystem 8.1 configuration registers 8.1.1 magnetometer calibration control magnetometer calibration control register id : 44 access : read / write comment : controls the magnetometer real-time calibration algorithm. Size (bytes): 4 example response: $vnrrg,44,1...

  • Page 101: Status Registers

    Um001 101 8.2 status registers 8.2.1 calculated magnetometer calibration calculated magnetometer calibration register id : 47 access : read only comment : calculated magnetometer calibration values. Size (bytes): 48 example response: $vnrrg,46,1,0,0,0,1,0,0,0,1,0,0,0*70 offset name format unit descr...

  • Page 102: Factory Defaults

    102 um001 8.3 factory defaults settings name default factory value magnetometer calibration control 1,3,5.

  • Page 103: Command Prompt

    Um001 103 8.4 command prompt the command prompt provides a fast and simple means of configuring and monitoring the status of the sensor by typing commands to the unit using the serial port. 8.4.1 list available commands commands for the system subsystem can be accessed by typing in ‘hsi’ at the comm...

  • Page 106: 9  Velocity Aiding

    106 um001 9 velocity aiding velocity aiding provides a method to increase performance of an ahrs sensor for applications where the sensor is subjected to constant accelerations. 9.1 overview ahrs fundamentals an attitude heading reference system (ahrs) is a sensor system that estimates the attitude ...

  • Page 107

    Um001 107 when an aircraft is in a banked turn the accelerometer will measure gravity plus this centripetal acceleration which will result in a measurement vector that acts perpendicular to the wings of the aircraft as shown in the above figure. This will result in the ahrs estimating a roll angle o...

  • Page 108

    108 um001 actual attitude which is derived from the flight simulator. Moving from left to right are three separate types of attitude estimators shown in order based upon the accuracy of their derived solution. The most accurate solution is proved by the inertial navigation system (ins). This type of...

  • Page 109

    Um001 109 velocity measurement rate the performance of the velocity compensation will be affected by both the accuracy of the velocity measurements and the rate at which they are applied. To ensure adequate performance the velocity should be provided at a rate higher than 1hz. Best performance will ...

  • Page 110: Configuration Registers

    110 um001 9.2 configuration registers 9.2.1 velocity compensation control velocity compensation control register id : 51 access : read / write comment : provides control over the velocity compensation feature for the attitude filter. Size (bytes): 8 example response: $vnrrg,51,1,0.1,0.01*5a offset n...

  • Page 111: Status Registers

    Um001 111 9.3 status registers 9.3.1 velocity compensation status internal register this register is not listed in the public user manual. It is not recommended to supply this register to customers unless there is a specific reason to do so. Velocity compensation status register id : 52 access : rea...

  • Page 112: Input Measurements

    112 um001 9.4 input measurements 9.4.1 velocity compensation measurement velocity compensation measurement register id : 50 access : read / write comment : input register for a velocity measurement to be used by the filter to compensate for acceleration disturbances. Size (bytes): 12 example respons...

  • Page 113: Factory Defaults

    Um001 113 9.5 factory defaults settings name default factory value velocity compensation control 1,0.1,0.01.

  • Page 114

    114 um001 please read carefully: information in this document is provided solely in connection with vectornav technologies, llc (“vectornav”) products. Vectornav reserves the right to make changes, corrections, modifications, or improvements to this document, and the products and services described ...