Development of a non-contact multi-axis reverse engineering measurement system for small complex objects

Abstract

This study presents the development of a non-contact multi-axis measurement system, which consists of a circular triangulation laser probe system, a multi-axis CNC engraving machine, and a PC, to digitize the 3D profile of small workpieces. The information in the whole measuring system, comprising a personal computer, a CNC engraving machine controller, and a controller of the circular triangulation laser probe, was integrated technically. Three scanning methods for the developed measurement system were proposed to configure the scanning path, namely the multiple-fold scanning method, the rotational scanning method, and the radial scanning method. The homogenous transformation matrix method was used to calculate the data registration of different digitized data sets. The measurement error of the development system was analyzed by digitizing a designed 3D test carrier. The root mean square error was about 0.028 mm and was obtained through a comparison between the digitized, reconstructed data and the measured data obtained with a CNC coordinate measuring machine (CMM). The developed system was applied successfully to the reverse engineering measurement of some small complex models, such as a tooth model and a toy model.