An Experimental Study of a Redundantly Actuated Parallel Manipulator for a 5-DOF Hybrid Machine Tool

This paper deals with the experimental study of a redundantly actuated parallel manipulator for a 5-DOF hybrid machine tool. Based on the kinematics of the redundantly actuated parallel manipulator, the inverse dynamics is derived by using the virtual work principle. A position and force switching control strategy is used for the two extendible chains of the parallel manipulator. Further, the difference predictive control is presented for the extendible chain with force mode. The parallel manipulator is incorporated into a 5-DOF hybrid machine tool. Linear and circular contouring experiments of both the hybrid machine tool as well as its corresponding nonredundant counterpart with the redundant limb removed are conducted to evaluate the machine performance. Finally, the machine experiment is used to demonstrate the machine's applicability.