Cross-shaped Fe-Ga alloy three-dimensional force tactile sensor and friction recognition

A three-dimensional force tactile sensor was designed based on magnetostrictive and tunnel magnetoresistance effects. The voltage output model of the 3D force sensor was derived, establishing the relationship between the output voltage and the three-dimensional force applied to the sensor. The structure of the sensor unit was optimized using COMSOL Multiphysics simulation software. An experimental platform was set up to test the static and dynamic performance of the sensor. The experimental results showed that the sensitivity of the sensor unit was 164.63 mV/N within the range of - 1.5 N to 1.5 N, and the average error between the experimental and theoretical values of the output voltage was 3.41%. The sensitivity of the sensor to normal forces in the range of 0 N to 6 N was 41.365 mV/N, and the sensitivity to tangential forces in the range of 0 N to 3 N was 49.636 mV/N. The dynamic voltage output of the sensor varied by no more than 4.65%, and the response time was shorter than that of human skin. The sensor was installed on the joints of a robotic hand and used to slide along the surface of an object. By comparing the output voltages of each unit, the friction coefficient of the object's surface could be accurately identified. The results showed that the sensor exhibited good static and dynamic characteristics, enabling perception of object information and precise manipulation of the robotic hand, thus improving the human-machine interaction process.