Development of a High-Performance Laser Interferometer for Roll Measurement(Mechanical Systems)

A practical system has been developed for the measurement of roll that occurs with the movement of a machine tool unit. The system consists of a double-path optical heterodyne laser interferometer, and a V-shaped reflector composed of two plane mirrors. To take a measurement, a laser head, the interferometer, and the reflector are set in a straight line, as for standard types of laser measurement. The sensitivity of the measurement which reflects a laserbeam at 8-points on the plane mirrors of the reflector was estimated at 1.6704×10^mm/" (detected length/unit angle of roll). The sensitivity was twice of the system that uses 4-points reflection which has been previously reported by the authors. In order to investigate the roll that occurs in a machining center with a milling space of 800mm×550mm×500mm, measurements were taken by means of 8-points system. From the results, it was confirmed that the reproducibility better than 10" in 99% confidence interval can be achieved.