On-machine three-dimensional monitoring technique using machining laser

An on-machine three-dimensional monitoring system has been developed that uses machining YAG laser as a source of light for monitoring. In the monitoring stage, the output of the laser is decreased. The reflected light from a workpiece is taken out with a beam sampler on the way of the optical system, and observed by CMOS image sensor. This system can measure both Z-direction depth and the position of X–Y-direction. Because the same laser and the optical system are used, the system has no gap of an optical axis between the measurement and the machining, and also has no limitation of viewing angle. Every three-dimensional shape which can be machined by laser beam can be measured. In this paper, system configuration, monitoring technique and the experimental results are described.