Design and optimization of a novel six-axis force/torque sensor for space robot

• A six-axis force/torque sensor is developed based on strain gauges for space robot.
• The novel sensor measures the force/torque depending on through-hole beams.
• The sensor is optimized by the response surface methodology (RSM).
• The accurate positions of strain gauges bonded are obtained by strain distribution.
• The experimental results show that the sensor has a good performance.

With the development of Chinese space technology, the construction of Chinese Space Station (CSS) has been on the agenda. The space robot takes a critical function in the CSS. It is an important tool in completing space tasks such as on-orbit assembly, maintenance, manipulation assistance, payload care and astronaut on-orbit support. The six-axis force/torque sensor equipped on the space robot could sense the three orthogonal forces and torques simultaneously, which will play an important role in the force control of space robot. Considering the dimension and compatibility, we designed a novel six-axis force/torque sensor based on strain gauges for the space robot. Different with the traditional Maltese cross beam, it is a novel structure with through-hole beam. Compared with the usually optimization method by trial and error, employing the response surface methodology (RSM) to acquire the optimum dimensional parameters is proposed in this paper. To get the accurate positions of the strain gauges bonded on the elastic body, strain distribution analysis on path is adopted. In the end, the sensor is manufactured and the calibration system is developed. The experimental results show a good performance of nonlinearity, repeatability, stability, hysteresis, sensitivity, and accuracy.