Development Of A Novel Scattered Triangulation Laser Probe With Six Linear Charge-coupled Devices (ccds)

摘要

The objective of this paper is to develop an inexpensive, robust, and precise scattered-type triangulation laser probe system with six linear charge-coupled devices (CCDs), that can be used to measure simultaneously the distance and inclination angle of a workpiece surface. The developed system has been configured and assembled based on Scheimpflug's principle. Through the specific arrangement of the six linear CCDs, four different measurement modules for the developed system were possible, namely the standard triangulation probe module, the double triangulation probe module, the pentagon-like triangulation probe module, and an approximately circular triangulation probe module. Angular measurements of an inclined surface were possible using the double triangulation probe module. The measuring range of the developed laser probe was +2 mm and the resolution was 2 μm/pixel. The performance tests among the different measurement modules of the developed probe and the commercial circular triangulation laser probe OTM3-03 have been carried out. The measurement uncertainty of the developed laser probe system, with respect to different surface roughness and slope, was generally smaller than +20μm within the measuring range using the pentagon-like triangulation probe module with the statistical methodology of skewness (S_k) and kurtosis (K_u) analysis by setting the appropriate threshold values for S_k and K_u, respectively. The developed probe has been integrated with a PC-based 3-axis micro-positioning stage to construct an automatic non-contact 3D measurement system and to digitize the 3D profile of a small complex object.