Automated laser scanning system for reverse engineering and inspection

Abstract

Recently, laser scanners have been used more often for inspection and reverse engineering in industry, such as for motors, electronic products, dies and molds. However, due to the lack of efficient scanning software, laser scanners are usually manually operated. Therefore, the tasks that involve inspection and reverse engineering processes are very expensive. In this research, we propose an automated measuring system for parts having a freeform surface. In order to automate a measuring process, appropriate hardware system as well as software modules are required. The hardware system consists of a laser scanning device and setup fixtures that can provide proper location and orientation for the part to be measured. The software modules generate optimal scan plans so that the scanning operation can be performed accordingly. In the scan planning step, various scanning parameters are considered in the generation of optimal scan paths, such as the view angle, depth of field, the length of the stripe, and occlusion. In the scanning step, the generated scan plans are downloaded to the industrial laser scanner and the point data are captured automatically. The measured point data sets are registered automatically and the quality of point data is evaluated by checking the difference between the CAD model and the measured data. To demonstrate an automated measuring system, a motorized rotary table with two degrees of freedom and a CNC-type laser scanner with four degrees of freedom are used.