A METHODOLOGY FOR MACHINE-TOOLS ERROR-CORRECTION USING REFERENCE PARTS

In this paper, a methodology is presented for machine tool error corre ction which uses reference parts as metrological standards. These refe rence parts have the same geometric shape and weight as real workpiece s. Consequently, the proposed methodology minimizes the uncertainty wh ich arises from geometric interpolation, but still yields satisfactory results for multi-axis machine error characterization. A generalized error model is derived to describe the relative error motion between t he tool and the workpiece. Iterative search algorithms are presented w hich increase the effectiveness of the error characterization process. Three case studies are described which demonstrate the application of the methodology for four sample reference parts on three different ma chines. The results from these studies show that the error correction method can be used to characterize the positioning errors with estimat ion accuracy approaching the resolution of the machines.