A New Self-decoupling Five-dimensional Force/Torque Sensor for Rehabilitation Robot

Abstract

Multi-dimensional force/torque sensor is an important part of the rehabilitation robot system. Double holes strain beam is a sensitive structure of force sensor with high precision and high stability. Also it has the advantage of load invariance and deformation parallelogram. According to the requirements of force sensor for the rehabilitation robot system, a novel five-dimensional force/torque sensor based on double holes strain beams was proposed in this paper. Its sensitive structure consists of six double holes strain beams which are divided into three groups. In each group, the common-mode signal is used to measure the spatial force and the differential signal is used to measure the torque. Finite element simulation analysis and experimental results show that the developed five-dimensional force sensor has the advantages of small multi-component coupling and high linearity. The new 5-DOF sensor is a “Θâ€shaped structure and the“-†inside of “Θ†is a freely rotating handle that can be used for patients to hold or fix affected limb with a palm gloves. Its comprehensive measurement accuracy can reach 2% FS and can be applied directly to the rehabilitation robot system.