Advanced Control Strategies For The Cnc Machine Tool Table Position Servo System

In recent years, compared with other types of servo systems, hydraulic servo system has some advantages which are that the the power-mass ratio(or force-mass ratio) of hydraulic components is big and that the velocity and the response of the system are fast and that the anti-load stiffness of the system is great, etc. Hydraulic servo system is first used in land, sea and air forces in various fields. At present, the aircraft control systems and the manipulation of institutions are almost the hydraulic servo and hydraulic transmission. In the missile area, the various control system of medium-and long-range missile control system are almost using hydraulic servo system. Now, hydraulic servo system is widely used in various industrial produce. Therefore, the study of hydraulic servo system has important practical significance.In this paper, the numerical control machine tool table position control system is taken as my research object, and I establish a mathematical model of the system. Hydraulic servo system is a typical nonlinear system. First, the system is dealt with the Taylor series linearization method. Then, with the simulation tool of MATLAB, the unit step response of the system is gotten, but the dynamic performance and steady-state performance are not very satisfying. So the main objective is that in order to obtain good dynamic and static performance I design different controllers to control this system. In this paper, I introduce three kinds of control strategies:one is self-tuning of the parameters fuzzy PID control methods; The last one is series combination of the PID controller and the quadratic optimal controller's control methods; One is the phase plane partition nine-state controller's control methods. The system is separately simulated using these three methods. Comparing with the these simulation results on the numerical control machine tool table position servo system, we can analyze the amendatory effect of the dynamic performance and steady-state performance among the three kinds of control strategies and their respective advantages and disadvantages.By analyzing the simulation, We can draw the conclusions:overshoot and oscillation frequency of the unit step response with the self-tuning of the parameters fuzzy PID controller have been improved, but the rise time, the adjust time and the peak time all have been slightly extended; With the series combination of the PID controller and the quadratic optimal controller, the overshoot and oscillation frequency also have been improved as well as the rise time and adjust time, and only the peak time has a slight extension.With the phase plane partition nine-state controller, the system even reached the effect of no overshoot, no oscillation and smooth curves, and the adjust time also has been decreased, with only a slight extension of the rise time, the method not only enhances the rapidity of the numerical control machine tool table position control system, but also improves the smoothness of the system. Therefore, As far as the numerical control machine tool table position control system is concerned, the effect of the phase plane partition nine-state controller is best. In the dynamic performance and steady-state performance at the same time to achieve relatively good results, the series combination of the PID controller and the quadratic optimal controller is better than the self-tuning of the parameters fuzzy PID controller.