REDUNDANT ACTUATORS TO ACHIEVE MINIMAL VIBRATION TRAJECTORY TRACKING OF FLEXIBLE MULTIBODIES - THEORY AND APPLICATION

We address the problem of inverse dynamics for flexible multibodies, w hich arises, in trajectory tracking control of flexible multibodies su ch as space manipulators and articulated flexible structures. Previous research has resolved this trajectory tracking problem by computing t he system inputs for feedforward control of actuators at the joints. R ecently, the use of distributed actuators like electro-strictive actua tors in flexible structures has introduced a new dimension to this tra jectory tracking problem. In this paper we optimally utilize such actu ators to aid joint actuators for tracking control, and introduce a new inverse dynamics scheme for simultaneously (1) tracking a prescribed trajectory and (2) minimizing ensuing elastic deflections. We apply th is scheme for trajectory tracking of a two-link two-joint planar manip ulator with joint motors and distributed electro-strictive actuators. Experimental results are presented to contrast our new scheme with oth er existing methods.