Impedance Control for Free-flying Space Robots -Basic Equations and Applications-

One of the most important phases of a satellite capturing operation by a space robot is the contact phase. During the contact between the end-effector and grasping point, there is a risk that the target and the robot can be pushed away from each other by the contact force. An impedance control of the hand with respect to the inertial coordinate is effective in keeping the contact with the target. In this paper, we propose a method for impedance control for a space manipulator. The end tip of the manipulator is controlled like a mass-damper-spring system fixed at a point in space in spite of the reactive motion of the base. In order to verify the proposed method, numerical dynamics simulations are carried out. Furthermore, an application of the proposed control to orbital service mission is discussed