Abstract
This paper treats the positioning control problem of the endtip of space manipulator without con-trolling the motion of the spacecraft which is the manipulator's base. The conventional local feedback at each joint is not applicable for such a case, because the position and orientation of the endtip cannot be functions only of the joint displacements. We propose a sensory feedback scheme for space manipulators based on the artificial potential defined in a sensor coordinate frame. In this scheme, information measured with a visual sensor on the base is fed back to the joints in term of control torques. Since the base's motion changes the view of the visual sensor, the manipulator must track the target seeming to move. However, we can prove that the endtip asymptotically approaches thee target by using the Liapunov's method. Finally the effectiveness of the proposed scheme is shown by results of computer simulation for a 6-link space manipulator model.
