Motion Planning for Redundant Parallel Kinematic Mechanism Using Joint Torque Distribution

This paper presents the motion planning for the redundant parallel kinematic mechanism using joint torque distribution that satisfies a path of the end-effector. The redundant parallel kinematic mechanism more numbers of actuator than numbers of degrees-of-freedom, and it has the advantage of bigger workspace than non-redundant parallel kinematic mechanism by eliminating singularities. The redundant parallel kinematic mechanism, however, has the problem not to able to select the unique motion of actuator for the motion of the end-effector. In this paper, the method of motion planning is presented, that is to find out joint torque distribution with dynamic modeling and to find out unique motion of actuators for minimizing the energy of actuators. The dynamic modeling is compensated with the frictional effects, and is verified by comparing torques and energy with measured values. Also two cases of experiments with a redundant parallel kinematic mechanism, Eclipse-II, are performed to verify the motion planning. And two cases of simulations are examined.