Vibration Suppression Technology Research On Robust Control For High Prcision And Velocity NC Machine Tool Droved By Linear Servo System

When permanent magnet linear synchronous motor (PMLSM) drives directly numerically-controlled machine tools, because of the break of permanent magnet linear motor armature iron core and discontinuity of stator winding, there are some uncertainties as parameter perturbations and nonlinear etc. At the same time, because of the system's uncertainties such as the load resistance disturbance, permanent magnet linear synchronous motor servo system is an uncertain system.Therefore, this paper studies on the NC machine vibration caused by the load disturbances variation based on robust control strategy.First,based on the H_∞control strategy theory,in order to restrain the disturbances generated by the uncertainties of the load, this paper presents an H_∞robust controller based on algebraic matrix Riccati inequality.This paper presents the augmented system state space model on the basis of building the system mathematical model, and an H_∞robust controller is obtained through soloving an algebraic matrix Riccati inequality with symmetrically positive solution.Then the supression of the load dislurbances variation capability will be studied based on H_∞robust control.Second,the adaptive fuzzy control mathematics model of PMLSM is built. Because of the time-varying and load disturbances, the vibration questions exist in the NC machine, and then the dynamic time-varying parameters mathematics model of PMLSM is deduced based on the existing mathematics model of PMLSM.Third, adaptive fuzzy robust H_∞controller is adopted. The controller proposed is comprised of an adaptive fuzzy controller and the H_∞robust controller, the adaptive fuzzy controller is used to approximate this ideal control law, the H_∞robust controller is designed for overcoming the approximation errors and the influence of the external disturbance. Then we use Lyapunov direct method to study the closed-loop control system stability.Finally, the simulation of the adaptive fuzzy robust H_∞control based on the PMLSM system is set. Based on the PMLSM simulation model,to verify the effectiveness of the algorithm,contrasted with PMLSM based on H_∞robust controller.For the machine vibration caused by load resistance,the vibration suppression based on adaptive fuzzy robust H_∞control system will be futher study.