TDF42IMU0 Fiber Optic Inertial Unit

Keyword：

Introduction

Accesories

Recommended

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, single axis, and dual axis modulation inertial units, meeting the needs of new unmanned platforms, water/torpedo weapons, as well as land and airborne weapon platforms for small size and high-precision inertial unit equipment. They 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 (100s)	0.05°/h
	Zero bias stability (10s)	0.1°/h
	Variable temperature zero bias stability	0.5°/h
Scale Factor	Full temperature scale factor	≤200ppm
Other indicators	Random walk coefficient	0.01°/√h
Other indicators	Input range	400°/s
Performance indicators of accelerometer
Deviation index	Deviation monthly comprehensive error	50μg
Zero bias indicator	Zero bias temperature sensitivity	50μg/℃
Scale Factor	Scale factor monthly comprehensive error	50ppm
Scale Factor	Scale factor temperature sensitivity	50ppm/℃
Range indicator	Input range	±20g
Whole machine characteristics
Environmental performance indicators	Operation temperature	-40℃～60℃
Environmental performance indicators	Storage temperature	-45℃～70℃
General requirements	Power supply	18～36V（DC）
General requirements	Stable power consumption	≤12W	Startup power consumption ≤ 25W

Electrical interfaces

The external electrical interfaces of the inertial group equipment include power interface, RS422 communication interface, and 100Mbps Ethernet interface. The socket model for the external electrical interface is J30JM-15ZKP43, and the matching plug model is J30J-15TJL.

1、2	External power supply	PCS power supply positive	24V
3、4		PCS power supply ground	Power Ground
5	200Hz signal output	IMU_TX1+	IMU data output positive
6		IMU_TX1-	IMU data output negative
9	Synchronization signal	IMU_RX1+	IMU synchronization signal positive
10		IMU_RX1-	IMU synchronization signal negative

Communication Protocol

a. RS422 serial port 1 outputs 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 2 outputs a time synchronization signal at sampling time 1 (with a valid rising edge, representing 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, and sends serial port 1 data after 50 μ s of rising edge emission.

Output Data Protocol

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).