Study On The Error Compensation Of Ultra-precision Machining And Software Development For Small Aspheric Surface

Development of ultra-precision machining equipment and technology is the foundation and key of advanced optical manufacturing technology, which is also an important symbol to measure the level of development of science and technology of a country. With the development of technology, ultra-precision machining is now moving to the nanometer accuracy, and the demand for machining accuracy become higher and higher. Aspherical ultra-precision machining is the peak of ultra-precision machining. Many domestic and foreign experts are actively researching, however, there are still many problems currently. The purpose of these studies is to develop a ultra-precision aspheric CNC error compersation equipment.Firstly, by literature review, research status of the field of processing technologies and equipments for aspheric surface have been preliminarily analyzed in this paper. Then the purpose for the development of aspherical NC software system and main contents for this paper have been put forward.Through in-depth study for several common models and methods of aspherical machining, we have established mathematical models of CNC path control, which are prepared for madding NC machining software. In order to improve the quality of surface machined, the reasons for non-uniformity of surface roughness have been analyzed, and a new method for variable feed rate has been proposed, in order to achieve the uniformity of the roughness after processing. Error compensation is the key technology of ultra-precision machining. By analyzing the cause for measured error, such as eccentric error, the radial wear loss of the radiu of grinding wheel and so on, the model for error compensation has been established and effective methed for compensation has been proposed.Using C++ Builder as the platform, based on the mathematical model, the software of error compensation machining for aspherical moulds is developed. The software interface is compact and nice, and it can be operated simply and conveniently. After setting the correlative parameter, program codes used for numerical control machining can been obtained. After processing, if the shape accuracy of the workpiece can not meet the requirements, the ultra-accuracy manufacture might be obtained through the compensation processing. By using modules of parametric trajectory display and dynamic processing simulation, processing parameters can be optimized and processing quality and processing efficiency can be improved.Finally, the software of aspheric processing compensation is tested, and the stability and reliability of running is verified. Processing experiments are carried by using NC program produced by the soft. Then experimental datas are collected and analyzed. The results show that NC program produced by this soft is correct and feasible. The anticipated aim of development has been reached, and the effectiveness of the developing software has been verified.