Robotic Simulation of On Orbit Servicing Including Hard Impacts

Abstract

Industrial robots are often used for the simulation of satellites during on orbit servicing. In order to cover also the docking phase, both robots are equipped with force-torque sensors, and the measured forces and torques are taken to compute the desired motion of the position controlled robots. Since the system dynamics of robots and of free floating bodies obviously differ, for each robot we distinguish between the really executed and the assumed satellite motion. The difference between the two motions is used to adapt the measured forces in such a way that they correspond to the satellite's trajectory. In this way the docking procedure can be visualized by two robots which closely follow the satellites' trajectories. Stability of the robot control is not compromised even if the dynamics of the satellites and the robots are totally different. Simulation results verify the approach.