Research On Active Vibration Control Of Motorized Spindle Base On Piezoelectric Stack

Motorized spindle is the core component of CNC machine tools,and its dynamic performance not only affects its own life,but also directly affects the machining accuracy and machining efficiency of CNC machine tools.During the machining of CNC machine tools,the vibration of the motorized spindle rotor is caused by the working conditions or internal disturbances,which makes the dynamic performance of the motorized spindle worse,and then affects the machining accuracy of the CNC machine tools.Taking the electric spindle as the research object,aiming at the problems inhibiting spindle rotor vibration,by means of theoretical analysis,simulation and experimental verification method,theory and method of active control of rotor vibration is studied.Firstly,the dynamic model of the rotor system of the motorized spindle bearing is established,and the sub model mainly consists of a laminated piezoelectric ceramic model,a rolling bearing model and a rotating shaft model.The relative theory of the sub model is studied,and the coupling relationship among the sub models is analyzed.On this basis,the dynamic model of the motorized spindle bearing rotor system is established.Secondly,the theory of optimal control algorithm is studied,and the LQR(Linear Quadratic Regulator)control algorithm and LQG(Linear Quadratic Gaussian)control algorithm are studied emphatically.Based on the dynamic model of the motorized spindle bearing rotor system,the state space model of the system is established,and the two control algorithms are simulated on the basis of the state space model of the system.According to the simulation results,two control algorithms are deeply analyzed.Finally,based on the simulation of LQR control algorithm and LQG control algorithm,taking the motorized spindle bearing rotor system as the research object,the experimental study of two control algorithms is carried out.Combining the experimental results,the LQR control algorithm and the LQG control algorithm are compared and analyzed,and conclusions are drawn.