Abstract:The space climbing legged robot based on Bio-inspired adhesive materials can be attached to the surface of the spacecraft and replace astronauts to complete extravehicular inspections, maintenance and other tasks, which is an effective way for unmanned in-orbit service and maintenance. The stable adhesion of robots and spacecraft is the premise of the work. In this paper, an optimization and control method of foot preload force is proposed to solve the problem of the influence of foot preload force on the adhesion stability of space climbing robots when it is in contact with spacecraft. Firstly, based on the characteristics of Bio-inspired adhesive materials, the stability constraints of the adhesive materials in the preloading stage and the adhesion stage are established. Secondly, the foot end force is optimized based on the quadratic programming under the constraints to ensure sufficient preload force and reduce the detached force on other feet. Finally, the optimized force distribution is realized through the admittance control based on the environmental stiffness identification. The results show that the admittance control can achieve the compliant control of the preload force, and the optimized preload force can reduce the normal desorption force of other adherent feet, and ensure the climbing stability of adhesion.