Dynamics Evaluation for Capturing a Target by a Space Robot. Effects of the Joint Stiffness.

Abstract

To capture a target on orbit is a fundamental task for space robots. As the target doesn't have a fixed base, it might be bounced away before the capture procedure is completed. When the target is much heavier than the robot hand, the manipulator controller gain affects such dynamics. This paper uses two measures for evaluation, namely, 1) contact time (duration until the target is bounced off) and 2) final relative velocities (target velocities relative to the hand when the target drifts away) . Analytical approximations of the two measures are derived and validated through numerical simulations and hardware experiments.