Analysis of a Pre-stressed Six-component Force/Torque Sensor Based on Stewart Platform

Abstract

In this paper, the structure analysis and finite element analysis (FEA) of a novel pre-stressed six-component force/torque sensor based on the Stewart platform are presented. The structure feature of the sensor is analysed in comparison with the traditional Stewart platform-based sensor. The measure principle of the sensor is introduced briefly and the mathematical expression of the sensor's force mapping matrix is built by using the screw theory. With the objective of achieving high measurement sensitivity, good isotropy and least effect of frictional moment, the key structural parameters of the sensor are determined and the prototype of the sensor is manufactured. The finite element method is employed for the analysis of the static and dynamic characteristics of the prototype. The finite element model of the prototype is built and the stress distribution of the elastic legs of the sensor is achieved. The natural frequencies and the natural vibration mode shapes of the prototype are obtained, which provide a reference basis for the sensor's dynamic analysis. The results of the theoretical deduction and the finite element analysis indicate that the structure is suitable for six-component force/torque sensor and the validity of the finite element model.