Optimum design of a novel redundantly actuated parallel manipulator with multiple actuation modes for high kinematic and dynamic performance

A novel redundantly actuated parallel manipulator with multiple potential actuation modes is proposed in this paper to conquer the drawbacks of the traditional planar 5R parallel manipulator. Firstly, some feasible topology configurations are presented and then an optimum scheme was achieved through some selection criteria. Kinematic analysis indicates that the redundant actuation modes have remarkable advantage over the non-redundant actuation modes because the redundant actuation ones can completely conquer the type II singularities within the theoretical reachable workspace. To investigate the dynamics, the Lagrangian formulation is employed to establish the uniformly dynamic model of the proposed parallel manipulator with multiple actuation modes. Based upon the dynamic model, two global dynamic performance indices are proposed for minimization by taking into accounts both inertia and centrifugal/Coriolis effects. Finally, the dynamic dimensional synthesis is performed subject to geometric constraints and some kinematic performance constraints. By using this approach, the designer can obtain a set of optimum dimensional parameters satisfying both the kinematic and dynamic performance. This approach can be extended to the optimum design for other high-speed parallel manipulators, especially for the ones with multiple actuation modes.