Experimental study on control of an asteroid sample return robot during contact based on complementarity modeling

In this paper, we propose a force and attitude control law of an asteroid sample return robot to obtain an enough constraint force for taking samples from the surface of the asteroid during contact. In a phenomenon of the impact between the robot and the asteroid, there is a complementary relation between the robot acceleration and the constraint force on the contact point. To pay attention to the complementarity, we derive a condition to constrain the robot on the surface of the asteroid based on complementarity system (CS). We design a control law which achieves the desired force and attitude with keeping the contact, and verify the effectiveness of the proposed control law by experiments.