Accuracy Enhancement for High Precision Gantry Stage

Abstract

Most industries, such as semiconductor, aerospace, biomedical and storage media, are accelerating their moves toward higher accuracy and faster speed on the factory machine for better products. The accuracy of a machine tool is the limiting factor in the accuracy of the finished parts. Errors in the machine tool motion produce a one-to-one error correspondence in the final workpiece. It is impossible to completely eliminate errors by design and/or manufacturing modifications. Hence, this study provides various methodologies for reducing and compensating for errors in real-time, thus improving the accuracy of workpieces.These improvements are two fold: firstly, software-based corrective approaches are adopted to improve the accuracy of motion system. Secondly, a model-based control strategy is proposed for the gantry stage to deal with nonlinear effects. Theoretical formulations are developed to analyze these issues, with extensive simulations and experimental results furnished to illustrate the effectiveness of the approaches.