Impedance matching in capturing a satellite by a space robot

In this paper, the contact motion between rigid body systems floating in space is formulated and dynamic conditions are investigated in order to capture a non-cooperative satellite. As for the theoretical investigation, impedance matching is discussed for the case in which the robot hand under impedance control approaches and collides with a passive target, and a specific impedance value is defined to yield the matching. The impedance matching is understood to give a criteria if the contact is maintained with a target, or the target is pushed away. Experiments are carried out using two robot manipulators as a motion simulator of the chaser and target. Through the experiments, the concept of the impedance matching is verified, and a satellite capture operation is demonstrated using the strategy that an impedance controlled probe is inserted into the thruster nozzle cone of the target.