Contour Tracking Control for Direct Drive X-Y Table Based on Equivalent Errors Model

Abstract

For the contour accuracy of direct drive X-Y servo system is susceptible to changes of the load parameters and nonlinear disturbances including the friction , A quadratic optimal position controller with sliding contour tracking controller based on equivalent errors model is proposed to improve contour tracking performance and the robustness. The position controller is designed by the factorization of quadratic optimization on frequency domain. Based on Equivalent Errors model including the equivalent contour error and tangential error, the contour tracking problem is converted to the stabilization of error dynamic system. Simulation and experimental results show that the effects of nonlinear disturbances are reduced effectively and the designed controller has high contour tracking accuracy and strong robustness.