Self-decoupling six-dimensional force/ torque sensor based on fiber bragg grating

A self-decoupling six-dimensional force/torque sensor based on Fiber Bragg grating is described, which is designed based on a spherical rotor and a double-layer beam. 14 FBGs are symmetrically attached to the elastic structure, enabling differential measurement of force/torque-induced strains. The sensing characteristics are obtained through simulation and experiment. Calibration experiments demonstrate low cross coupling errors of 2.26 %, 2.37 %, 1.49 %, 2.89 %, 1.79 % and 1.66 % within the range of ±5.72 N, ±5.72 N, ±5.72 N, ±0.206 Nm, ±0.206 Nm and ±0.147 Nm, for the detection of Fx, Fy, Fz, Mx, My and Mz, respectively. Compared to existing six-dimensional force/torque sensors, the designed sensor uses a spherical sliding structure to reduce dimensional coupling, simplifying calibration and maintenance. This sensor holds significant potential for broad application in six-dimensional force/torque measurement, particularly in robotics, medicine, and aerospace.