Active Control Of The Tool Spindle Runout

Tool spindle system runout, a very important indicato of the performance of machine tool, has always been received wide attention. Relevant internal and external scholars have done a lot of research and study. Traditional research mainly focuses on the accuracy of the rotary spindle measurement and evaluation, for the reason that the tool spindle system runout is a comprehensive and complex evaluation of the system with a lot of uncertainty. The most direct tool to improve the spindle rotation accuracy of the system is to improve manufacturing and assembly errors of the spindles, bearings, shanks and tools, however, a higher accuracy means higher costs.In order to meet the actual needs of microfabrication, tool spindle systems runout need to be explored the feasibility of active control. First the influencing factors and measurement methods of tool spindle system runout is discussed, and two different methods of measurement of tool spindle system runout were tested and analyzed, and compared.Based on the tool spindle system runout measurement and analysis, because of the complexity of the tool spindle system runout, active control of the systems is proposed. In order to investigate the reasonableness of the program, the tool spindle system dynamics models is explored first, mainly including the finite element model of the spindle tool system, ie unit model and assembly of the system model approach.On the basis of the tool spindle system dynamics model, this paper discusses the methods and the characteristics of the active vibration control and LQR controller. After transforming the system dynamics model of the tool spindle into the equation of state, the model was solved. Then the simulation experiments of LQR control on tool spindle vibration system is carried out. The control effect LQR controller is discussed. Then, to get rid of the difficulties of Q and R matrices selection for the LQR controller, we also proposed genetic algorithm for the optimization of Q and R matrices, and give the result of the simulation before and after the optimization to discuss the effectiveness of it.Next, based on feasibility of the tool in the spindle runout active vibration control system, we propose the use of active magnetic bearing control system for spindle tool runout control, and show specific embodiments.Finally, discussion of the factors affecting the measurement methods of tool spindle system runout is carried on. Two different measurement methods, namely wave dragon laser sensor system and LMS system plus eddy current sensor, are used to detect tool spindle system runout. By the analysis of the result, synchronization orbit of axes changes with speed, orbit graph shows that the shape of the rotary tool spindle system error mostly triangular prism, the runout correlates with the speed of rotation. Finally we compare the two measurement methods.