Motion regulation of redundantly actuated omni-directional Wheeled Mobile Robots with internal force control

Because of the complexity of the mechanisms of redundantly actuated omni-directional wheeled mobile robots (WMR), its motion regulation is a challenging problem, especially for consideration of the interaction force between the redundantly actuated wheels. The interaction force can be decomposed into motion-induced force and internal force, which are orthogonal between each other. Only the motion-induced force contributes to the motion of the robot, while the internal force abrades the wheels components, and causes the reduction of their life span. So the internal force should be eliminated or minimized. In this paper, kinematic model and dynamic model of redundantly actuated omni-directional WMR considering the interaction force is first established. A proportional differential plus motion regulator is presented. An integral feedback internal force controller is applied to minimize the internal force. Simulation results verify the effectiveness of the proposed control scheme. The robot is regulated successfully, and the internal force is reduced efficiently.