ON-MACHINE HIGH-PRECISION DEFLECTION MEASUREMENT BY MULTI-DIRECTIONAL LASER DISPLACEMENT SENSOR USING SCANNING EXPOSURE METHOD

抄録

We propose an optical displacement measurement sensor on a machine tool to measure the deflection of a metal-workpiece, which is as precise as a conventional contact-type dial gauge. Our sensor allows automatic and fast measurement by non-contact measurement. We have proposed a multi-directional triangulation system which uses a lens array consisting of four lenses, and scanning exposure method which scans the projection beam on a workpiece during the exposure time of an image sensor. Our techniques improved the accuracy by detecting the reflected light from four angles and scanned positions. In this paper, we show that our proposed method achieves on-machine displacement measurement of metal-workpieces with same accuracy as a dial gauge. In addition, we evaluate the measurement error in the shape of machining traces and show that our sensor measures the electrical discharge machining traces whose reflected direction characteristic is uniformity more precisely than the cutting machining traces.