Aspheric parts are attracting many researchers’ attention for their excellent optical properties. The commonly used manufacturing technology for aspheric parts are mainly based on dedicated high precision machines, resulting in high cost and restricted application fields. To polish this kind of parts on general CNC machine tools, however, the surface quality improvement is limited due to the problem of force-position coupling. In order to solve this issue, a force-position decoupling control method for abrasive polishing was studied, a corresponding comliant polishing tool system was developed, and the mathematical model of the tool system was established. In addition, a polishing force controller was designed, and the performance of the tool system was numerically simulated. Simulation results showed that the polishing tool system can effectively achieve the tasks of force-position decoupling and the stable control of the polishing force.

Aspheric surfaces of high precision and low roughness are widely used in the military field, the aeronautics and astronautics field and some high-tech fields. Therefore, research works on the methods and equipments of digitalized polishing for aspheric surfaces are a hot issue in the modern precision manufacturing. The traditional precision manufacturing mainly depends on the higher precision equipments to promote the surface quality of aspheric surfaces, but the cost of equipments seems to be extremely expensive. Taking the general CNC lathe of two axis interpolation as a platform, and basing on the controllable damping characteristic of the Magnetorheological Fluids (MRF), a new kind of compliant polishing tool system for aspheric surfaces is developed in this paper. The tool system keeps the polishing force to be stable by the torque servo unit of MRF, and implements the compliant polishing.

The tool position based on the general interpolation arithmetic will make sharp changes which bring a harmful influence to the mixed control of pose and position as well as the normal force in grinding process. In this paper, a new type of shape-adaptive tool is proposed for the common NC lathe. The effective of shape-adaptive and the stability of polishing force is studied utilizing the dynamic analysis software ADAMS, at the same time, the structural is optimized. The simulation outcome indicates that the tool could both adapt to the surface of workpiece and remove the influence brought by interpolation arithmetic.