A General Purpose Machine Vision Prototyper for Investigating the Inspection of Planar Webs

Abstract

In order for an industrial inspection system to be of utility in manufacturing it must be fast, accurate, and flexible. It would seem that the best method for creating flexible vision systems is to define a subclass of inspection problems where all the problems within the subclass have a number of common features. Such a subclass must be of interest to a number of manufacturers. It must also be reasonable, to solve. Once the subclass has been selected, the next logical step is to create a device that makes performing all the needed experiments on the various problems within the class easy. This work has four major objectives. The first objective is to define a meaningful subclass of inspection problems that are (a) of interest to a number of manufacturers, and (b) represent inspection tasks that seem reasonable within the current state-of-the-art of computer vision. The subclass selected for this work is the longitudinal planar web inspection problem under the two-dimensional imaging restriction. The second objective of this work is to create a vehicle that will allow the types of experimentation usually associated with the development of vision systems to be facilitated. This vehicle created is called a machine vision prototyper. The third objective of this work is to use the vision prototyper system to attack a particular planar web applications problem. The application considered is the problem of locating and identifying surface defects in surfaced hardwood lumber in a species independent manner. The fourth objective of this research is to indicate how the prototyper system can be used to attack a second planar web application problem. This application problem is the inspection of hardwood parts coming out of a molder. The utility of the vision prototyper system as an experimental tool is demonstrated on two of the three possible types of longitudinal planar web inspection problems. The results include the development of a vision system for a hardwood surfaced lumber surface feature detection problem, and a discussion of how the prototyper can be used to attack the problem of inspecting hardwood parts coming out of a molder. (Abstract shortened by UMI.)