Design Of Contour Servo Controllerfor The Two-dimensional Precise Workbench

Precision motion control technology is widely used in ultra-precision machine tools, medical instruments. In order to improve the positioning precision of the system, this paper mainly took the two-dimensional positioning platform driven by ball screw as application background, and then designed and analyzed the single axis servo controller and contour servo controller for the system.First of all, based on the theoretical derivation and numerical simulation by Matlab, position loop was closed in the PMAC controller, speed loop and current loop were closed in the drive, in order to simplify the model,speed control unit is simplified to First-order inertia link, and then completed a single axis servo simulation model.Second, this paper used nonlinear PID algorithm to design the position loop of single axis servo control system, improved the positioning precision of the control system. Then on the basis of the principle of compound control, speed feed-forward and disturbance observer was designed to improve the system’s performance. Based on that, this article designed the variable gain crossing coupling control algorithm to make the original open loop control into the closed loop control to improve the contour precision.Finally, based on the Turbo Pmac, this article built the experimental platform, detected the open-loop characteristic of the system, compared the steady error of the semi closed loop and the closed-loop control, and then proved that the speed feed forward can effectively reduce the following error of the system, at last edited the nonlinear PID control algorithm, through comparing the system steady error, the response rate, this paper verified the correctness of the nonlinear PID controller.