A Moment and Torque Sensor With a Birfield-Type Structure, Using a Mechanically Self-Decoupled Method

A moment and torque sensor with a birfield-type structure using a mechanically self-decoupled method was proposed, analyzed, fabricated, and tested. The self-decoupling operation was achieved by arranging the moment and torque transmission along different routes by designing a birfield-type mechanical structure. Two pieces of magnetostrictive material 2826MB were pasted on the sensitive parts along the moment and torque transmitting route for detection purposes. Then, the moment and torque were measured on the sensitive parts and were found not to affect each other. The sensor can realize noncontact and dynamic detection based on the Villari effect. Experiments were conducted to test the performance of the sensor. Experimental results showed that the sensor had a good self-decoupling performance, with an error less than 1.10%. The sensor had an excellent linear performance. The sensor can also work dynamically with an error less than 3.54%. Based on the uncertainty analysis, the total uncertainty of the sensor is 0.015, which ensures the stability in multiple precision measurements. Furthermore, the sensor displayed advantages of working passively, wirelessly. All these advantages enable the sensor potential applications in cutting tools, sealed gearboxes, etc.