Development And Research Of Platform For Aspheric Surface Polishing

Aspheric surface includes all surfaces expect for sphere and plane surface, which hasgood optical properties. So it is mainly used in optical surfaces. The last step of asphericsurface process is generally polishing. In the conventional processing methods, this step ismainly done manually by workers, but the quality is unstable and it is inefficient. Since theeighties of last century, countries of the world have been racing to develop the keytechnologies which is required to achieve full process automation when polish asphere. Thesupple aspheric surface polishing technique based on magnetorheological fluid torque servodevices has become a hot research point of scholars at home and abroadThis paper, combining the National Natural Science Fund Project "Research on smoothpolishing technology of aspheric optical surface based on magnetorheological fluid devices(51075188)", mainly researches aspherical workpieces (hyperboloid ellipsoid workpiece andworkpiece), researching on the core problem of smooth control of the aspherical surfaceultra precision polishing process. Based on the systematic analysis on the principle of spatialcoupling, the paper researches decoupling mechanism, and develops an aspheric compliantpolishing servo platform t based on MRF torque servo devices. The paper creatively changestraditional mode to control by position servo to the torque servo to control, and the polishinghead pose is controlled by NC program, to really realized the force-separationsynchronization control when polishing the aspheric optical surface. The main researchcontents and research methods of the paper are shown below.1. Study on the rheological properties of magnetorheological fluid and the constitutiveequation, master the working characteristics of MRF torque servo device using in the paper.2. Determine the overall project, according to the polishing principle and mechanicaldesign theory, complete the design of key parts and the whole of the modeling syste m, anddevelop polishing system test bench.3. Analyze the basic theory of aspheric surface polishing, research the force positioncoupling mechanism, establish the decoupling model, and put forward a kind of MTSD force based on the decoupling control of the aspheric surface polishing, draw three dimensionalpolishing trajectories, and establish the mathematical model of material removal rate constant.Through Matlab software to analyze the effect of polishing pressure and rotational speed ofworkpiece on the material removal rate. Establish polishing pressure control model andworkpiece speed control model in the polishing process respectively, and accord to the modelto draw the polishing pressure and rotational speed of workpiece curve with the machiningpoint coordinates by Matlab software, to provide the basis for the latter part of the polishingexperiment.4. Use masterCAM software to generate NC program, and use professional softwareCIMCO, set parameter of upper machine and machine tool, realize PC and NC lathecommunication.5. Study the test of aspheric polishing controlled by torque, collect polishing pointcoordinate, calculate the values torque of theory and of real then compared them, control thepolishing torque by regulating the excitation current regulation of MTSD device real-time torealize removed materials uniformly and to improve the surface roughness of the workpiece.