In order to achieve real-time monitoring of stress state of robot’s wrist

combining the fiber Bragg grating(FBG)with classic Maltese cross-beam structure

a 3D force sensor based on FBG for robot wrists is designed.The finite element analysis software ANSYS is used to study the strain distribution characteristics and dynamic performance of the sensor

and the optimal pasting position of the FBG on the beam is determined.Through differential measurement methods and summation

measurement of 3D force for self-decoupling and temperature compensation is realized with only 5 FBG.Finally

the experimental platform is established to study the sensitivity of the sensor and th

e inter-dimension coupling.The experimental results show that the sensitivity of the sensor in direction of

x

y

and

z

in the force measurement range of 0~100N 16.475

15.068

and 8.651pm/N

respectively

and the inter-dimensional coupling errors are 1.3%

0.8%

and 1.5%

respectively.The structure of the sensor is simple and can work reliably

and can be applied to 3D force monitoring of the robot’s wrist.