An automated inspection system

An automated inspection system for manufactured parts is proposed using a cloud of 3D measured points of a part provided by a range sensor, and its CAD model. In spite of the high precision attained by coordinate measuring machines (CMM), range sensors offer significant advantages for dimensional inspection: a high speed of digitisation and the capacity to take 3D measurements on the it-hole surfaces of a part without physical contact. The system first registers a cloud of 3D points with a CAD model of the part, then segments the 3D points in different surfaces by using the CAD model, and finally measures the control of the specified tolerances on the part. Results of the inspection are displaced in two ways: visually, using a colour map to display the level of discrepancy between the measured points and the CAD model, and a hardcopy report of the evaluation results of the tolerance specifications. Two range sensor technologies have been tested and inspection results are compared with the results obtained with a CMM.