Design and optimization of a high sensitivity joint torque sensor for robot fingers

Abstract In order to protect target objects from being destroyed, the torque exerted on finger joints should be accurately measured and used for controlling the dexterous robotic hand. However, restricted by the space of the finger joint, it is difficult to improve the sensitivity of the finger joint torque sensors. To solve this problem, a novel joint torque sensor with floating beams and supporting beams is designed based on an analysis of the traditional cross-beam torque sensor. The structure of the sensor is newly modeled and analyzed. Then response surface methodology (RSM) is employed to optimize the sensor structural parameters. A comparison of finite element analysis results and optimization results is used to estimate the sensitivity of the proposed sensor and verify the optimized attachment positions for the strain gauges. Finally, a finer joint torque sensor is fabricated and calibrated. The results show a good performance of repeatability, nonlinearity, hysteresis and sensitivity.