Dimension optimization of a planar 3-RRR parallel manipulator considering motion and force transmissibility

As the intrinsic characteristic of parallel manipulators, motion/force transmission performance has an extremely important influence on the performance of parallel robot systems. This study focuses on the evaluation of the motion/force transmission performance and dimensional optimization of a planar 3-RRR parallel manipulator by considering its motion/force transmissibility. An inverse kinematic analysis of the manipulator is presented. The local transmission index (LTI) of the manipulator is calculated, and two global design indices are defined based on the LTI for performance evaluation and dimensional synthesis. The process of optimal kinematic design of the manipulator based on performance charts is then presented. The optimized manipulator has a large workspace in area and shape, within which it has good motion/force transmissibility.