Fig. 1. Schematic diagram of fiber Grating sensing

Fig. 2. Schematic diagram of sensor structure

Fig. 3. Sensor structure diagram

Fig. 4. Calibration experimental system

Fig. 5. Coupling interference in x ，y，z direction

Fig. 6. Structure diagram of extreme learning machine neural network

Fig. 7. Algorithm flow chart

Fig. 8. Relationship between MSE and decoupling time

Fig. 9. Linear characteristics after decoupling in three directions

Fig. 10. Coupling error output after decoupling in three directions

Fig. 11. Comparison of four algorithm errors