Modeling and control of robotic automatic polishing for curved surfaces

This paper presents the solutions adopted for a robotic automatic polishing platform for finishing machining on curved surfaces to reduce cost and improve quality on such manual finishing operations. The polishing platform was built and the polishing process was studied. In order to accomplish the control of polishing force, the relationship among the robot, sensor, polishing tool (cutter) and the force impacted on the polished parts is established. On this basis, the model of removal distribution is built for each polishing path, a suitable path spacing algorithm further obtained by the same scallop height, and an effective planning algorithm of tool location is proposed. An active and passive compliance control polishing model is set up by explicit force control based on position and the methods of tilting polishing tool with elastic sponge disk. Finally, validation experiments are performed on mold parts of NAK80 steel. The experiments display that the robot achieves a relatively constant force control effect by the active and passive compliance force control. The results show that the proposed automatic polishing platform has the good ability of effectiveness and feasibility for polishing on curved surfaces, and is able of achieving a mirror effect surface and keep a good global uniformity.