Machine vision is a familiar technology in manufacturing and industry, and is used in an ever-growing range of tasks from simple code reading and assembly verification to robotic guidance and 3-D profiling. Theapplication of machine vision for gaging and metrology is not new, but advances in technology are enabling higher precision and more accurate measurement than might have been achieved even a few years ago. Even as technology improves, it is important to consider some fundamental techniques for successfully integrating machine vision for metrology, and know how to avoid some of the problems that could affect the results of a measurement application.
This article focuses only on techniques for production systems, that is, inspection systems designed to perform 100% automated measurement on a production line. There are many camera-based, noncontact metrology devices designed for laboratory or off-line use, and these are highly recommended in that environment. However, those systems are outside the scope of this discussion.