Research On Dynamic Performance Analysis And Positioning Error Compensation Of Ultra-precision Grinding Machine Based On PMAC

With high precision components widely used in the fields of aerospace, weapons,electronic information and biomedicine, ultra-precision fabrication technology has beenpaid more attention worldwide. In recently years，it has become one of the key factorswhich indicate the national manufacturing level. Ultra-precision machine tools, as thebasic apparatuses to realize precision and ultra-precision machining, have gottenextensive attention from various countries. There is no doubt that foreign countries havemade many significant achievements in the ultra-precision machine tools fieldscurrently. However, it is still in the initial stage in China, which limits the developmentof sophisticated technology in national defence. Therefore, it is extremely urgent for usto design ultra-precision machine tools independently.Basic research on the self-developed ultra-precision grinding is discussed in thispaper. The main tasks are to obtain vibration characteristics of the whole machine,perfect the numerical control system based on PMAC, improve the precision of themoving parts and enhance the dynamic and static characteristics of the control system.First, dynamic performance of the assembly is analyzed by finite element analysissoftware ANSYS. The natural frequencies and vibrational modes of the assembly arecalculated, which provide the theoretical model for the research of machine tool’svibration characteristics.Then, the numerical control (NC) system of the ultra-precision grinding machine isimproved. According to the structure and function of the machine tool, the hardware andsoftware structure of the open NC system based on PMAC is analyzed in details. Thefriendly and simply operated interactive software of NC system is developed by themethod of modularization based on Visual C++6.0. The functional modules and theimplementation ways of software are discussed in depth.At last, in order to improve the dynamic and static characteristics, servo controlsystem is tuned by adjusting PID parameters，velocity and acceleration feed-forwardparameters. Based on the above work, position accuracy of the guideways is detectedand error compensation is executed. As a result, the position accuracy of the guidewaysis improved.The analysis and experiments in this paper lay a solid foundation for grindingprocessing of the ultra-precision grinding machine.