Research On Cnc System Of A Ultra-precision Lathe Milling Machine Tool Based On UMAC

In order to improve processing efficiency and precision of the complex workpiece, a more efficient method of ultra-precision processing technology has been explored in the engineering field. Lathe milling machining technology is one of the developping innovational methods. Complex processing model and high precsion requirement for the surface lead to the complexity of the processing technology. Currently, the developped countries have researched CNC systems for the high precision machine used for milling turning and grinding. This kind of technology has been used for the micro-structure workpiece. However, foreign mature CNC systems are very expensive, at the same time, the research on the CNC systems of lathe milling has just started in our country. The control accuracy and precision of our machine tool or CNC systems falled behind other developped countries. Therefore, making some research about ultra-precision milling complex machining CNC system is signifiacant.Firstly, according to the functions and control requirements of ultra-precision lathe milling machine tools,the hardware platform of lathe milling control system was built based on the UMAC controller. The structure of open CNC is that traditional PC was used as advancer to interacte with the users. And the controller was used as the lower computer to make the caculation, which has the advantage of software compatibility, the real-time computation and superior scalability. Then, VC++ 6.0 was used to develop PC operating software which contained communication, collection data, manual control, program downloads and so on.Secondly, on the basis of the electromechanical systems control theory, the spindle and linear motion axis were optimized by the PID algorithm in the UMAC. The step response and parabola response was did to optimize the dynamic and steady charcateristic of axis systems by changing parameters manually. If so, the system following error must be reduced.Finally, the processing of experiment was completed which includes turning of end surface and micro-structure on the cylindrical. The experimental results show that the developed CNC machining system can achieve the processing of end surface, cylindrical and micro-structure with stable and reliable performance.All these achievement of buliding the hardware platform, developping PC opertating software for the CNC system, PID parameter adjustment and the experiment of the turning will have the reference value for the development of other types of ultra-precision machine tool in terms of control system.