Planning spiral motion of nonholonomic space robots

A freeying space robot with a 6 DOF manipulator cannot follow an arbitrary trajectory in the 9D generalized coordinates(3 of the satellite orientation and 6 of the manipulator) with only manipulator joint control, though it was shown to be commonly controllable in the literature. In this paper, we propose a method to approximate the desired 9D path by introducing a perturbation around it. We call the approximated trajectory the \spiral motion." A computational scheme for planning the spiral motion is presented, and is followed by computer simulation that illustrates the effectiveness of the scheme.