Performance Analysis and Comparison of Three Planar Parallel Manipulators

This work presents a comprehensive performance evaluation and comparison of three planar parallel manipulators with PPR limbs. The kinematic model of the redundant 4-PPR planar parallel manipulator is established, upon which the inverse position model and singularity are analyzed. Then, the evaluations of dexterity, velocity and stiffness performance are achieved. Performance comparison between the redundant manipulator and another two non-redundant 3-PPR planar parallel manipulators, one with Δ-shape structure and the other with U-shape structure, is presented. Simulation results reveal that the U-shape manipulator owns the greatest velocity performance. Moreover, the redundant one possesses the best dexterity and stiffness performance.