Dynamic behavior and parameter sensitivity of the free-floating base for space manipulator system considering joint flexibility and clearance

The joint flexibility and clearance greatly affect the dynamic behavior of the free-floating base when space manipulators operate due to the dynamic coupling between the manipulators and the free-floating base. Based on the Lagrange–Euler method and momentum conservation, the dynamic model of a free-floating space manipulator system with joint flexibility and clearance is obtained. With this model, the coupling effects of joint flexibility and clearance on the dynamic response of the free-floating base are analyzed and some case studies are conducted to investigate the effects of different parameters of joint flexibility and clearance on the free-floating base. Further, the parameter sensitivity of the free-floating base for space manipulator system with joint flexibility and clearance is analyzed using the improved response surface method. According to the analysis of response surface method, we can increase the joint clearance size or decrease the dynamic friction coefficient to improve the stability and motion accuracy of the free-floating base position and attitude. This work points out the direction for reducing the base disturbance and provides a basis for the optimization design for free-floating space manipulator system.