Modeling for Elastomer Displacement Analysis of Capacitive Six-Axis Force/Torque Sensor

Estimation of elastomer displacements is crucial for predicting the capacitance variation and studying the sensing performance of capacitive six-axis force/torque(F/T) sensors. This paper presented a novel analytical model to improve the estimation accuracy of elastomer displacements for Y-type elastomer capacitive six-axis F/T sensor. The proposed Y-type elastomer capacitive six-axis F/T sensor consists of three main parts, including a Y-type elastomer, a capacitor and a printed circuit board(PCB). Then, the analytical model is established to estimate the elastomer displacements based on Statics and Timoshenko beam theory. In this analysis, the measurement principle of proposed sensor is depicted and the various elastic beams deformations of the elastomer are analyzed with less simplification. Also, FEA simulation is adopted to verify the accuracy of analytical model. The results showed the maximum relative error is 8.12%. Compared with the analytical model of previous method, these obtained analytical model is confirmed to be accurate and higher efficiency. The proposed analytical model is expected to provide a specific theoretical model of estimation, design and optimization for capacitive six-axis F/T sensors.