1 、System workflow
The inertial guidance system consists of two workflows, a combined navigation process and a pure inertial navigation process.
1.1、Start-up prompt message
Connect the cable, power up the system, monitor the COM1 interface information through the serial debugging tool of the test computer, and send workflow commands to the COM1 interface through the serial debugging tool after the interface displays "Please enter NaviMode within 20s! "If the command is not sent within 20s, the system will automatically enter the internal saved workflow after 20s.
1.2、Portfolio navigation process
After entering the combined navigation process, the first binding satellite information, if the satellite does not position, it is in the state of waiting for satellite information; when the satellite information is valid, it enters the alignment state, alignment time 1min, alignment period requires the inertial guide stationary, alignment is complete, the inertial guide can move, the system is in the combined navigation state.
1.3、Pure inertial navigation process
After entering the pure inertial navigation process, the first 1min coarse alignment, if the satellite information is valid, the binding satellite information for 1500s fine alignment, if there is no satellite information, the static base must be aligned 1500s; alignment is completed after the transfer to the pure inertial navigation state, the inertial guidance can move.
2、System configuration commands
2.1 、Configuration scheme and save
The inertial guidance system provides 4 serial ports (configuration number: com2~com5) externally, and provides one internal storage channel (configuration number: file), each serial port function assignment and related configuration are as follows.
Table 4 Inertial guidance system serial port function assignment table
After the system is powered on and the COM2 port displays the startup information, you can input commands such as COM2~COM5 serial port baud rate configuration, serial port protocol and update rate setting, etc. Each command output will return "cmd ok" if successful, otherwise it will display "cmd error ". After the input is finished, type "saveconfig" to save the configuration, and the next reboot will automatically call this configuration, if you don't enter this command, the serial port configuration will be restored to the last saved configuration after the next reboot.
2.2、 Configuration queries
Typing "log loglist" or "log rxstatus" through COM2 will list all the configurations of COM2~COM4, including the following:
1.Serial port number, serial port baud rate, serial port protocol and update rate.
2.Function module open status: including zero speed correction status and smooth processing status, open as enable, close as disable; carrier type;
3.Internal storage status information: including the file name of the last file, remaining space, etc;
4.Initial binding latitude and longitude;
5.System number and factory date;
6.Software version number: including preprocessing software version number and navigation software version number;
7.Operating mode: including combined navigation (DGI) and pure inertial navigation (INS).
2.3、 Baud rate configuration
Enter the following command in this mode to enter the serial port baud rate configuration:
com comX BAUDRATA
Where X is 2~4 and BAUDRATA is the baud rate in bps.
For example, to set the baud rate of COM2 port to 460800bps, enter the following command:
com com2 460800
2.4 、Serial RS232 configuration
When the configured serial port is RS232 (if the configured serial port is COM3-COM4, you need to do the adapter wire, see section 4.2 Electrical Interface for wiring definition), the command is as follows:
rs232 COMX
where X is 2~4.
For example, to set COM3 port to RS232, enter the following command:
rs232 com3
2.5、 Serial port RS422 configuration
When the configured serial port is RS422 (if the configured serial port is COM2, you need to do an adapter cable, see section 4.2 Electrical Interface for wiring definition), the command is as follows:
rs422 COMX
where X is 2~4.
For example, to set the COM2 port to RS422, enter the following command
rs422 com2
2.6、 Update rate configuration
The configuration of COM2~COM5 and memory file port GPFPD, BDFPD, inspvasa, and inspvasb protocols is performed through COM2 with the following configuration commands:
log comX/file LOG ontime updataTime
where comX can be com2~com4 configuration number, file is the memory interface configuration number; updataTime represents the update time, which can be 5(0.2Hz), 1(1Hz), 0.2(5Hz), 0.1(10Hz), 0.01(20Hz) and other periods that can be 200Hz division, unit s.
LOG indicates the protocol name, which can be inspvasa, inspvasb, gpfpd, bdfpd.
For example, to configure the COM2 port to output 10Hz GPFPD data, enter the following command via COM1:
log com2 gpfpd ontime 0.1
If you need to output 10Hz bdfpd data at COM2 at the same time, then you can enter the following command via COM1 again:
log com2 bdfpd ontime 0.1
As another example, to store the 1Hz inspvasa protocol data in the internal memory of the inertial guide, the following command can be entered via COM2:
log file inspvasa ontime 1
If you want to turn off a protocol, configure the command as follows：
log comX/file LOG off
The configuration of the rawimusb and rawdata protocols for the COM2~COM4 ports and the memory file port is performed via COM2 with the following configuration commands:
log comX/file rawdata onchange
If you want to turn off the rawdata protocol for this serial port, the configuration command is as follows：
log comX/file rawdata off
If you want to disable all protocols on the serial port, the command is as follows：
unlogall comX/file
Note that increasing the update rate or outputting several protocols at the same time, these will increase the amount of data sent by the serial port, and you need to configure the baud rate to match it before using it, otherwise it may cause lost numbers. In general, the larger the amount of data, the higher the baud rate required.
2.7、 Initial value latitude and longitude configuration
Initial latitude and longitude configuration, the configuration command is
initialpos LONGITUDE LATILUDE
where LONGITUDE and LATITUDE are the configured local latitude and longitude values, in degrees.
2.8、 Function module configuration
The function modules with on configuration mainly include zero speed correction and output position smoothing.
2.8.1、 "Zero speed correction" configuration
Zero speed correction function mainly refers to the inertial guide to detect the sensitive information, if the inertial guide is judged to be zero speed, then make the corresponding correction.
If the satellite information is invalid for a long time in the combined navigation state, and the user wants to get pure inertial navigation information, it is recommended to turn off the zero speed correction mode.
The zero speed correction configuration command is as follows:
inszupt switch
The switch value is disable or enable, where disable means turn off the function and enable means turn on the function.
2.8.2 、"Position output smoothing" configuration
The position information in the INSPVASA and GPFPD protocols is inertial navigation position information, in order to get smoother position information, the navigation software has added the position output smoothing function, the smoothed position noise is smaller.
The default "position output smoothing" in the combined navigation process is off, but for the convenience of the user, this function can be configured with the following command:
possmooth SWITCH
The switch value is disable, enable, where disable means turn off the function, enable means turn on the function.
2.9、Satellite serial port mapping configuration
In the process of use, if the satellite card does not have extra serial ports for configuration or use, you can use the satellite card serial port mapping to the external interface COM4, which is configured with two commands as follows:
connect gpscard com2
connect gpscard com3
connect gpscard disable
Send connect gpscard com2 command, it will map COM2 of satellite card 718D to COM4 of external connection port, then COM4 port must be configured as 230400 to configure satellite navigation card board, this command will make inertial guidance work in abnormal state, after configuring the board, you need to reboot inertial guidance, then inertial guidance can be normal state. This command will make the inertial guidance work in an abnormal state, and the inertial guidance will not be saved after the reboot.
Send connect gpscard com3 command to map COM3 of satellite card 718D to COM4 of external connection port, at this time, COM4 port baud rate must be configured to COM3 of 718D for normal communication, if you need to save, send saveconfig command.
Sending the connect gpscard disable command will restore the external COM4 serial port to the internal CPU output port.
2.10、 Carrier type configuration
According to the different carriers installed in the inertial guidance, the carrier type configuration is required, and for different carrier types, different algorithms are processed within the system.
The configuration commands are as follows:
carrier vehicle/ship/air
In order, they are vehicle, ship and airborne.
After the configuration is complete, you need to enter the save command saveconfig, and then hard start or enter the #reset command, the carrier type configuration will be valid after the start. The inertial guide does not support the current configuration for current use during use, it must be restarted.
After the carrier type is configured as vehicle type, the inertial guide is required to be installed on the vehicle and fixed, and the inertial guide is oriented in the same direction as the front of the carrier vehicle, with an error of not more than 10 degrees.
2.11 、Online RTK
When using online RTK processing, you need com2 to enter the following commands.
possmooth disable
com5, the com1 port of the 718D, is configured as follows
serialconfig com1 9600 (variable baud rate, according to the actual DTU configuration)
interfacemode com1 rtcmv3 novatel on
Saveconfig
2.12、 GNSS antenna pole arm configuration
Depending on the relative mounting relationship between the antenna and the inertial guide, an antenna rod arm configuration is required. The value of the rod arm between the configured inertial guide to the antenna must be measured to the nearest millimeter (mm), any rod arm measurement error will go directly into the position error of the inertial guide output, when installed and used, the inertial guide is as close as possible to the main antenna, especially in the horizontal position. This command is required before the inertial guide is aligned with the static base or in the middle and before the dynamic base is aligned. Once this configuration is complete, it needs to be saved via "saveconfig".
The configuration includes the master antenna arm configuration and the slave antenna arm configuration.
The master antenna configuration command is as follows:
setimutoantoffset1 armX armY armZ
The configuration commands from the antenna are as follows:
setimutoantoffset2 armX armY armZ
where armX, armY and armZ are the configured pole arm values in meters, representing the component of the vector from the inertial guide to the antenna phase center within the inertial guide vector coordinate system, which is chosen to be right front up (XYZ). For the example in Figure 5, armX and armY should have negative values and armZ should have positive values.
Figure 4 Schematic diagram of the antenna pole arm
2.13 、Output lever arm setting
The default value for the product output lever arm configuration is [0, 0, 0] (upper right front), which is the position and velocity value at the output inertial guide. If you need to output the position and velocity of the user's test point, you need to set the output lever arm according to the relative mounting relationship between the test point and the inertial guide.
The bar arm value between the configured inertial guide and the test point must be measured to the nearest millimeter (mm) and any bar arm measurement error will go directly into the position error of the inertial guide output. This command is required before the inertial guide's static base is aligned or before the inertial guide's dynamic base is aligned. Once this configuration is complete, it needs to be saved via "saveconfig".
The output lever arm configuration command is as follows:
setimutosensoroffset armX armY armZ
Where armX, armY and armZ are the configured bar arm values in meters, representing the vector from the inertial guide to the test point as a component within the inertial guide vector coordinate system, which is chosen to be right front up (XYZ). Figure 6 example, armY, armZ should be positive values.
Figure 5 Schematic diagram of output lever arm
2.14 、Mounting angle setting
2.10、 Mounting angle setting
Both the attitude and heading information output by the product are the Euler angles of the product coordinate system with respect to the geographic coordinate system. The angular mounting relationship between the product and the carrier coordinate system is the mounting angle, and the configuration default value is [0, 0, 0] (pitch, heading, roll), which means that the product coordinate system is considered to overlap with the mounting carrier coordinate system. If there is a mounting angle for the product installed on the carrier, and the product is required to output the Euler angle of the carrier coordinate system relative to the geographic coordinate system, the mounting angle should be set according to the relative mounting relationship between the product and the carrier.
The installation angle configuration command is as follows:
vehiclebodyrotation angleX angleZ angleY
where angleX, angleZ, and angleY are configured mounting angle angle values in degrees, representing the angle from the carrier coordinate system to the combined navigation system coordinate system in the order of pitch, heading, and roll.
Note: This function will cause the output angular velocity, acceleration, and attitude to change with the settings.
3 、Protocol format
The output protocols supported by the product are shown in the following table.
Table 5 Description of output data protocols
3.1、 SNCNAVPVTB
Example of inertial configuration command:
log com2 sncnavpvtb ontime 1
Table 6 sncnavpvtb format
3.2 、GPFPD
Example of inertial configuration command:
log com2 gpfpd ontime 1
Example of inertial guidance output
$GPFPD,2083,199022.049,271.356,-2.149,0.767,39.7085178,116.1311212,39.93,-11.422,-0.077,0.050,1.500,27,0,1*59
Table 4 GPFPD format
3.3 、BDFPD
Example of inertial configuration command:
log com2 gpfpd ontime 1
Example of inertial guidance output
$BDFPD,2105,355160.246,90.96184,-1.14427,1.01899,39.71066564,116.11209956,46.076,-0.0037,-0.0065,0.0147,20,16,0*68
Table 5 BDFPD format
3.4 、Short Message Protocol Header
There are two types of short header protocol headers, one is ASCII and the other is binary.
ASCII short header
3.5、32-bit CRC checksum
The C code history is as follows
#define CRC32_POLYNOMIAL 0xEDB88320L
/* --------------------------------------------------------------------------
Calculate a CRC value to be used by CRC calculation functions.
-------------------------------------------------------------------------- */
unsigned long CRC32Value(int i)
{
int j;
unsigned long ulCRC;
ulCRC = i;
for ( j = 8 ; j > 0; j-- )
{
if ( ulCRC & 1 )
ulCRC = ( ulCRC >> 1 ) ^ CRC32_POLYNOMIAL;
else
ulCRC >>= 1;
}
return ulCRC;
}
/* --------------------------------------------------------------------------
Calculates the CRC-32 of a block of data all at once
ulCount - Number of bytes in the data block
ucBuffer - Data block
-------------------------------------------------------------------------- */
unsigned long CalculateBlockCRC32( unsigned long ulCount, unsigned char*ucBuffer )
{
unsigned long ulTemp1;
unsigned long ulTemp2;
unsigned long ulCRC = 0;
while ( ulCount-- != 0 )
{
ulTemp1 = ( ulCRC >> 8 ) & 0x00FFFFFFL;
ulTemp2 = CRC32Value( ((int) ulCRC ^ *ucBuffer++ ) & 0xFF );
ulCRC = ulTemp1 ^ ulTemp2;
}
return( ulCRC );
}
3.6、 INSPVAS
The command is short message protocol output
Example of inertial configuration command:
log com2 inspvasa ontime 1 (ASCII)
log com2 inspvasb ontime 1 (binary)
ASCII example
%INSPVASA,1264,144059.000;1264,144059.002135700,51.116680071,-114.037929194,515.286704183,277.896368884,84.915188605,-8.488207941,0.759619515,-2.892414901,6.179554750,INS_ALIGNMENT_COMPLETE*855d6f76
INSPVAS format
This command is short message protocol output (output binary only)
Example of inertial configuration command:
log com2 rawimusb onchanged (binary)
RAWIMUS format
40μJ High refrequency erbium glass laser.High refrequency erbium glass laser.
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