Fig. 1. Fiber Bragg grating sensing principle

Fig. 2. Schematic diagram of flexible packaging of sensing unit

Fig. 3. Schematic diagram of loading

Fig. 4. Dimensions of sensing unit

Fig. 5. Simulation analysis of package body

Fig. 6. Longitudinal path stress profile

Fig. 7. Static simulation deformation cloud

Fig. 8. Mapping of load to wavelength drift

Fig. 9. Temperature simulation deformation cloud

Fig. 10. Temperature and wavelength drift mapping relationship

Fig. 11. Sensor fabrication process

Fig. 12. Robots with FBG sensing unit

Fig. 13. Experimental platform for tactile calibration

Fig. 14. Static pressure response curve

Fig. 15. Static pressure error analysis

Fig. 16. Temperature response curves

Fig. 17. Static temperature error analysis

Fig. 18. Experimental platform for tactile perception

Fig. 19. Contact temperature response curve

Fig. 20. FBG wavelength drift versus contact force and temperature

Fig. 21. FBG wavelength drift versus temperature for different contact forces

Fig. 22. FBG wavelength drift versus contact force at different temperatures

Fig. 23. Co-awareness experimental errors