Research Of Robotic Grinding And Polishing Technology For Large Freeform Surface

In recent years, with the rapid development of aerospace and advanced manufacturing technology, grinding and polishing machining is essential of the precision products processing. So far, the grinding and polishing processing for large freeform surface of transparent parts is still mainly rely on manual, it is time-consuming and laborious, low efficiency, and the uniformity of surface quality is poor, the precision is not high.The papers, which are on automatic polishing technology based on industrial robot technology, have been read. For polishing of transparent parts based on previous researching results, the key technology of robotic automated grinding and polishing is further studied. The main contents of this paper include:1) An automated polishing system is established based on industrial robot, and designing a new active and passive flexible polishing tools, the tool is able to imitate manual polishing, and overcome the contradiction between the rigidity and flexibility of robot.2) By using the finite element contact analysis method, the pressure distribution model of polishing tool is built. Then the material removal model of polishing tool for transparent part is established based on Preston and Archard theories. And the experimented results also verify the correctness of the model.3) Through the force analysis of the flexible polishing tool on polishing processing, the polishing robot force control system is developed based on the sliding mode variable structure control theory(SMCS), and realized the robot to imitate manual polishing operation, real-time monitoring and control of contact pressure between the polishing disk and the workpiece, adjust the robot pose, ensure constant pressure polishing process of polishing.4) Robotic automated polishing system is used as experimental platform to execute grinding and polishing experiments. The experimental results showed that the proposed automated polishing technology can meet the precision machining requirements of transparency: Surface roughness Ra<(10~20) nm, and without mechanical and optical defects of transparency parts.In summary, the research and application based on transparent parts of the industrial robot polishing technology, not only has theoretical value, but also has important practical application value and potential economic value.