Image processing for machine vision measurement of hot formed parts

Dimensional measurement of hot parts, such as forgings, is desirable to permit real-time process control, but typically is inconvenient because of the difficulty in working with very hot workpieces. Machine vision technology is employed in many industries for rapid, in-process non-contact gauging, but in this particular application there are implementation issues. These include workplace illumination, image processing, pattern analysis and extracting important features from the processed images. This paper describes experiments conducted on acquiring and processing images of hot forgings, specifically large open die forgings, and how the use of inexpensive CCD cameras with infrared-pass filters can greatly simplify the image processing and pattern analysis tasks for a machine vision measurement system.