Design and implementation of a 2-DOF 5R parallel mechanism with a coaxial-driven layout

Abstract

In order to expand and improve the reachable workspace of planar parallel manipulators, a 2-DOF 5R parallel mechanism with a coaxial-driven layout is proposed. The configuration analysis and structural design are carried out, and the kinematic model is presented to conduct simulation analysis. The results indicate that the layout with the axes of the two driving devices overlapping has a larger workspace and a more compact structure. Meanwhile, a closed-loop PID control system is established to evaluate the accuracy of the proposed mechanism and analyse the kinematic error under different gain parameters. Simulation results indicate that the kinematic performance of the mechanism has improved. The control system is constructed based on using a motion control card as the primary control component and two servo motors as the drive device. Additionally, gain values are adjusted by the driver to reduce the deviation of the servo motors. Finally, the design of the prototype is deployed, and the experiment proved that the 2-DOF 5R planar parallel mechanism (PPM) with a coaxial-driven layout has the advantages of a large workspace, fast dynamic response, high stiffness, and easy control. The design of the 2-DOF 5R PPM solves the problem of single operation and high repeatability, which is increasingly utilized in the fields of electronics, food, daily chemicals, and pharmaceuticals.