Small Size TDF37IMU0 Fiber Optic Inertial Unit Low Power
Consumption
Overview
Fiber optic inertial units have the advantages of small size, light
weight, low power consumption, and high accuracy. They can be used
to design pure strapdown systems, meet the needs of new unmanned
platforms, water/torpedo weapons, as well as land, airborne, and
missile weapon platforms for small size and high-precision inertial
unit equipment, and have dynamic measurement functions for carrier
angular and linear motion information.
Performance
Project | Content | Index | Remark |
Performance indicators of gyroscope |
Zero bias indicator | Zero bias stability (10s) | 0.2°/h | |
Variable temperature zero bias stability (100s) | 0.5°/h | |
Scale Factor | Scale factor nonlinearity | ≤20ppm | |
Other indicators | random walk coefficient | 0.02°/√h | |
input range | 400°/s | |
Performance indicators of accelerometer |
Deviation index | Zero bias repeatability | 0.3mg | |
Zero bias indicator | Zero bias temperature sensitivity | 50μg/℃ | |
Scale Factor | Scale factor repeatability | 300ppm | |
Scale factor temperature sensitivity | 20ppm/℃ | |
Range indicator | input range | ±20g | |
Whole machine characteristics |
Environmental performance indicators | operation temperature | -40℃～65℃ | |
storage temperature | -40℃～60℃ | |
General requirements | power supply | 18～36V(DC) | |
Stable power consumption | ≤8W | Startup power consumption ≤ 15W |
Communication protocols
a. RS422 serial port 1IMU raw data output. Output three channels of
angle increment information, three channels of speed increment
information, IO count information, temperature information, with a
data frequency of 200Hz (raw observation values without
interpolation are compensated for errors). The data protocol is
shown in Appendix A, and the output data is not lost;
b. RS422 serial port 2IMU synchronous data output. Output the time
synchronization signal for sampling time 1 (valid rising edge,
rising edge time represents the sampling time of the inertial
sensor), RS422 differential signal, pulse width of 10 ± 2 μ s,
sampling signal interval of 5ms ± 20 μ s, rising edge and falling
edge level establishment time not exceeding 100ns, sending serial
port 1 data after 50 μ s of rising edge emission.
c. RS422 serial port 3 gyroscope raw data output. Transmission
rate: 460.8kbps ± 2kbps; Verification method: even verification;
Output format: RS422; Output information: The gyroscope receives an
external 2kHz square wave through the 422 interface, synchronized
at the falling edge of a positive pulse (or the gyroscope sends
data in broadcast form with a 2k update frequency); Scale factor:
see test report.
Output Data Protocol
The raw data output frequency of IMU is 200Hz, and the protocol is
as follows:
a. Baud rate: 460800bps;
b. Output format: RS422, 1-bit start bit, 1-bit stop bit, 8-bit
data bit, no checksum;
c. Data frequency: 200Hz;
d. Communication Protocol: The communication protocol is detailed
in the table below;
e. All undefined bits are filled with 0 by default. When
transmitting multiple bytes, the low byte comes first and the high
byte comes last.
Byte Number | Meaning | Data Type | Length | Description |
1-4 | packet header | unsigned int | 4 bytes | 0x55,0x55,0x55,0x55 |
5-8 | Packet Count | unsigned int | 4 bytes | IMU internal count value |
9-12 | X gyroscope data | Single precision floating point | 4 bytes | linear measure |
12-16 | Y gyroscope data | Single precision floating point | 4 bytes | linear measure |
16-20 | Z-gyroscope data | Single precision floating point | 4 bytes | linear measure |
21-24 | Add table data to X | Single precision floating point | 4 bytes | M/S |
25-28 | Y adds table data | Single precision floating point | 4 bytes | M/S |
29-32 | Z adds table data | Single precision floating point | 4 bytes | M/S |
33-34 | X adds temperature to the meter | unsigned int | 2 bytes | linear measure |
35 | IO1 pulse counting | unsigned int | 1 byte | - |
36 | IO2 pulse counting | unsigned int | 1 byte | - |
37 | Sign position | unsigned int | 1 byte | - |
38 | checksum | unsigned int | 1 byte | Sum of 1-37 bytes |
Note: X. The Y-axis and Z-axis gyroscope data are angle increments,
measured in degrees. X. The data on the Y and Z axes is the speed increment, measured in
meters per second. Temperature unit: degrees, positive=(D33+D34 * 256) * 0.01,
negative=(D33+D34 * 256-65536) * 0.01. The definition of the flag is shown in Appendix 1 (b). |
Electrical interfaces
The device connector model is J63A-242-015-261-TH, used for power
supply and communication, and the mating plug is
J63A-12-015-161-JC.
Pin | Connectivity | Signal Name | Signal Characteristics |
1,2 | External power supply | PCS power supply | 24V |
3,4 | PCS Power Supply | Power Ground |
5 | 200Hz signal output | IMU_TX1+ | IMU data output positive |
6 | IMU_TX1- | IMU data output negative |
9 | Synchronization signal | IMU_SYN+ | IMU synchronization signal positive |
10 | IMU_SYN- | IMU synchronization signal negative |
Dimensions
Weight: ≤ 0.5kg
