Fuzzy logic control for the contouring accuracy of XY positioning system

In this paper, we propose a fuzzy logic controller for XY positioning system. In motion control, the major sources of uncertainties are friction, inertia, stiffness and disturbances. These uncertainties should be taken into account by any high performance robust motion controller. A cross coupled controller utilizes all axis position error information simultaneously to produce accurate contours. However, the existing cross coupled controllers cannot overcome friction, backlash and parameter variation. Also, since it is difficult to obtain an accurate mathematical model of the XY system, we investigate a fuzzy logic cross coupled controller of an XY positioning system. The overall control system consists of three parts, the position controller, the speed controller, the fuzzy logic controller. New contour error vector computation method is also presented. The performance of the proposed controller is shown to be effectiveness through some simulations and experiments.