Machining, Measurement, and Control Laboratory

On-machine Measurement Using Laser Displacement Sensor under Simultaneous Five-axis Control of Target Position and Orientation
Y. Kimura, Y. Nagai and S. Ibaraki

This paper presents an on-machine measurement system of the workpiece’s geometric accuracy by using a laser displacement sensor installed on the machine’s spindle. The position and the orientation of a workpiece is controlled by rotary axes of a five-axis machine tool, such that the entire three-dimentional geometry of workpiece can be measured without changing its setup. In such measurement, measurement errors are influenced by motion errors of rotary axes. This paper aims to simulate and compensate measurement errors caused by geometric errors of rotary axes. To this end, first we formularize influences of rotary axes geometric errors on the measured workpiece geometry. Then, a measurement test was carried out to experimentally evaluate the validity of the present simulation scheme of measurement errors. It was found that simulated error profiles of the target geometry match well with measured profiles, and that such measurement errors can be significantly reduced by applying the proposed compensation.
Key words: On-machine measurement, Laser displacement sensor, Geometric error.