Performance Research of Planar 5R Parallel Mechanism with Variable Drive Configurations

All joints of the serial mechanism are active ones, while only some joints are active ones for the parallel mechanism. Thus, there is a variety of drive configurations with different active joint selections. Drive configuration will affect the performance of parallel mechanism and the effect deserves further study. A planar 5R parallel manipulator with the capability of adjusting drive configurations in real time is proposed in this paper. Based on the deduced Jacobian matrices, performances of the 5R parallel manipulator are analyzed, considering three symmetrical drive configurations. Typical kinematic performance indices, such as local conditioning index and kinematic manipulability, are adopted to give a complete illustration of the performance variation. Then, the optimal adjustment of driven configurations is proposed and studied, considering local conditioning index. Simulation results reveal that the performance of the 5R parallel manipulator improves obviously through the reasonable combination of different drive configurations in the workspace. The drive configuration adjustment proposed in this paper provides a novel potential way to enhance the comprehensive performance of the parallel mechanism.