Contouring accuracy improvement of parametric free-form curves — A Fuzzy Logic-based Disturbance Compensation approach

In high-precision manufacturing, the paramount issue is to diminish contour error regarding multi-axis contour following tasks. In particular, machining problems such as large contouring errors will likely occur in a complex shape machining task due to the inherent friction force and/or external disturbances. Among the possible solutions to dealing with this difficulty, the Cross-Coupled Controller (CCC) is arguably the most commonly used approach for contouring accuracy improvement in multi-axis contouring control systems. Therefore, to attain satisfactory contouring accuracy, this paper exploits the CCC approach for control of free-form contour following tasks in biaxial motion control systems. Additionally, a Fuzzy Logic-based Disturbance Compensator (FLDC) is presented to enhance tracking performance as well as contouring accuracy. Moreover, an integrated motion control structure consisting of a modified version of CCC and two proposed FLDCs is further developed in this paper to improve contouring performance. Several experiments on free-form contour following tasks have been performed on an X-Y table driven by two linear motors. Experimental results validate the feasibility of the proposed approach.