Title :
Neural network stereo image segmentation for directed coordinate measuring machine part programming
Author :
Chan, V.H. ; Bradley, C. ; Vickers, G.W.
Author_Institution :
Dept. of Mech. Eng., Victoria Univ., BC, Canada
Abstract :
Reverse engineering is used in industry to create a geometric model from an existing physical part. Often, this task is initiated by the collection of 3-D data using a contact sensor, such as a touch probe, mounted onto the end effector of a coordinate measuring machine (CMM). A CCD camera, mounted along with the touch probe, is utilized to automatically direct the digitization process. Stereo images taken with the CCD camera are used to both segment the object into its component surface patches and to locate the object on the CMM bed. A Kohonen self-organizing network is used to segment the stereo images. Areas of constant grey level intensity are used as seed locations from which patches are grown in the network. The stronger patches (those in areas of constant grey level intensity) compete and eventually dominate neighbouring patches in areas of less grey level consistency. In this winner take all strategy, the number of surface patches need not be known beforehand, and learning phases are unnecessary. This is ideal for reverse engineering, as the object shape and complexity is often unknown. Surface patch location is achieved by matching segmented patches between the stereo image pairs. Experiments on a planar test object demonstrate this system´s robustness. By combining a CCD camera with the CMM touch probe, an automated 3-D digitization system is developed
Keywords :
CAD/CAM; CCD image sensors; computational geometry; image matching; image segmentation; learning (artificial intelligence); self-organising feature maps; stereo image processing; 3D data; 3D digitization system; CAD; CCD camera; CMM touch probe; Kohonen self-organizing network; constant grey level intensity; contact sensor; coordinate measuring machine; end effector; geometric model; industrial reverse engineering; learning phases; machine part programming; neural network; object location; planar test object; segmented patch matching; stereo image segmentation; touch probe; winner take all strategy; Charge coupled devices; Charge-coupled image sensors; Coordinate measuring machines; End effectors; Image segmentation; Neural networks; Probes; Reverse engineering; Solid modeling; Tactile sensors;
Conference_Titel :
Communications, Computers and Signal Processing, 1997. 10 Years PACRIM 1987-1997 - Networking the Pacific Rim. 1997 IEEE Pacific Rim Conference on
Conference_Location :
Victoria, BC
Print_ISBN :
0-7803-3905-3
DOI :
10.1109/PACRIM.1997.620322