Five Bar Planar Manipulator Simulation and Analysis by Bond Graph

This work focuses on the bond graph modelling method and its application on multi-body system, especially on the five-bar parallel robot. Five-bar parallel robot is comprised of four arms, two revolute actuators and five revolute joints. This paper adopts five-bar parallel robot in symmetric configuration as simulation object. As it will be used as a pickup and placing machine, its workspace is fixed on Cartesian coordinate. The relationship between the two rotating angles and end effector’s desire position is built by inverse kinematics. Bond graph is used to describe moment, torque, velocity, angle relationships. In this project, the dynamic performances between arms, motors at robot basement and end effector will be researched. In this paper, an investigation about how to use bond graph to model DC (direct current) servo motor and an integrated motion control system is carried out. During a typical end effector point-point displacement, the torque change between arms is plotted. Finally, 3-D animation experiment is conducted. Experiment results show that bond graph can simulate robot dynamics performance without having to make a large number of equations. It is able to simulate and solve five-bar kinematics problem in the process.