Modeling and Force Control of Robotic Polishing System for the Wheel Hubs

Polishing is a key step in the manufacturing of wheel hubs since it will affect the appearance and performance of the wheel hubs. In this paper, a robotic polishing system is designed for the wheel hubs. To facilitate variable selection and controller design, the polishing process is firstly modeled. A roughness model considering the classic Preston material removal model is proposed. The roughness model aims at controlling the surface roughness rather than the material removal of the workpiece, which is more suitable for the robotic polishing for the wheel hubs. Then, a position-force hybrid control framework is proposed for the robotic polishing system. To improve the performance of the force control, a three-level rule-based adjusting method is designed and robot motion trajectory is planned based on the resolution surface of the wheel hubs. Finally, polishing experiments on the wheel hubs are fully conducted to demonstrate the effectiveness of the proposed modeling and control method of this paper.