1.Application Products
ER-FNS-03 Low Cost 3 Axis FOG North Seeker
2.1 Triaxial Fiber Optic Gyro
2.1.1 Performance Indicators
Table 1 Performance requirements of fiber optic gyroscope
No | Indicator | Value |
1 | Operating temperature (℃) | -45~+75 |
2 | Start time τ (s) | ≤5 |
3 | Dynamic range (° / s) | ≥±400 |
4 | Zero-bias stability (1σ,/h) (100s Standard Deviation) | ≤0.3 |
5 | Zero bias repeatability (1σ,/h) | ≤0.3 |
6 | Random walk coefficient (°/ √h) | ≤0.03 |
7 | Non-linearity of scale factor (ppm) | ≤100 |
8 | Asymmetry of the scale factor (ppm) | ≤100 |
9 | Repeatability of scale factor (ppm) | ≤100 |
10 | Extreme temperature scale factor (ppm) | ≤200 |
11 | Bandwidth (Hz) | ≥200 |
2.1.2 Interface Protocol
Table 2 FOG interface communication protocol
Data frame | Output Data | Edition | First edition | ||
Frame description | |||||
Content | Types | Asynchronous serial data frame | |||
source | Fiber Optic Gyro | ||||
Standards compliant | RS-422; baud rate 614400bits / s; 1bit start bit, 8bit data bit without parity, 1bit stop bit | ||||
Update rate | 400Hz | ||||
Element | Signal name | Signal description | |||
1 | Head of Gyro data | 0xEB | |||
2 | 0x90 | ||||
3 | Gyro Data | 4-byte 32-bit signed integer, character 3 is the lowest 8 bits, and character 6 is the highest 8 bits. Negative data are in two’s complement form. The scale factor is: 1 | |||
4 | Gyro Data | 4-byte 32-bit signed integer, character 3 is the lowest 8 bits, and character 6 is the highest 8 bits. Negative data are in two’s complement form. The scale factor is: 1 | |||
5 | Gyro Data | 4-byte 32-bit signed integer, character 3 is the lowest 8 bits, and character 6 is the highest 8 bits. Negative data are in two’s complement form. The scale factor is: 1 | |||
6 | Gyro Data | 4-byte 32-bit signed integer, character 3 is the lowest 8 bits, and character 6 is the highest 8 bits. Negative data are in two’s complement form. The scale factor is: 1 | |||
7 | Reservation | Fill in 00; | |||
8 | Reservation | Fill in 00; | |||
9 | Reservation | Fill in 00; | |||
10 | Reservation | Fill in 00; | |||
11 | Reservation | Fill in 00; | |||
12 | Reservation | Fill in 00; | |||
13 | Reservation | Fill in 00; | |||
14 | Reservation | Fill in 00; | |||
15 | Temp/condition | Temperature calculation formula: output according to standard 18B20, the negative number of data is in two’s complement form. The scale factor is: 1/16 (the output code value is multiplied by the scale factor to obtain the temperature in Celsius) | |||
16 | Status: 0 ~ 3, update period: 1ms | ||||
17 | 15,16 data description | State 0: gyro temperature; 1: reserved; 2: reserved; 3: working state | |||
18 | Cycle count | The value of each packet of data is increased by 1, and after 255, the next packet of data is 0;; | |||
19 | Checksum | After accumulating characters from 3 to 18, take the lower 8 bits as the checksum |
2.1.3 Power Supply
Power supply type: + 5V -5V GND
Power quality: ± 5%, ripple 20mv
Power (3 way):
Transient: + 5V: 5.0W; -5V: 2.0W
Steady state: + 5V: 3.0W; -5V: 1.5W