Self-calibration for motion errors of rotary and linear axes on a five-axis machine tool and workpiece geometric errors
Tomoyasu Kato, Soichi Ibaraki
Abstract
Many methods have been studied to measure motion errors of a five-axis machine tool. To calibrate rotary axis motion errors, most of them assume that motion errors of three linear axes are sufficiently small. In general, the motion accuracy of a machine tool is always subject to gradual change, due to e.g. environmental changes or mechanical aging. Our goal is to develop a scheme for a five-axis machine to self-calibrate its own motion errors and then to compensate for them automatically. Environmental changes and mechanical aging often affect not only rotary axes but also linear axes. We propose a measurement method to simultaneously calibrate the positioning error of linear axes and geometric errors of rotary axes without using an artefact of the pre-calibrated geometry.
Keywords: Self-calibration, machine tool, motion errors, rotary axes,linear axes
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