PSU Magazine Winter 1988

I RESEARCH Point of Inspection This professor's pioneering research may someday make computer-aided inspection an integral part of the manufacturing process. W e live in a time of computer– aided design (CAD) and computer-aided manufacture (CAM) where tens of thousands of parts are made and assembled each day. In some cases raw materials are fed in at the beginning of the line and crates of the finished product are delivered at the end. And amazingly a single computer can direct the entire process through the in– itial design , control of manufacturing, final packaging and inventory count. Ironically, this sophisticated system is thrown a very unsophisticated monkey wrench at the time of inspection. Human inspectors and even today's automatic techniques add time, cost and error fac– tors that don't make sense with an other– wise streamlined process. Faryar Etesami , associate professor of mechanical engineering and systems science at Portland State University, hopes to bring the whole process into the 21st century with development of computer– aided parts inspection. Etesami , a mechanical engineer with a Ph.D. from University of Wisconsin , joined the Portland State faculty in 1984 and quickly secured a grant from the Na– tional Science Foundation for his com– puter inspection research . "I have a good background in numerical control machine robotics and manufacturing processes so I know what I'm doing is realistic," he says. The research began with several plastic parts Etesami made in the shop. The parts simulate ordinary manufactured fasteners, with slots and holes in one and bolts and pins in another. By fractions of degrees these parts either fit into each other or don't. The ability to deviate slightly in size but still have the part perform its function is called tolerance, and it is designed in by the engineer. Etesami measures these parts with a microscope and positioning table and enters these coordinates into a computer which already contains the simulated geometry for the part. His research goal is Professor Faryar Etesami uses a vision system to measure manufactured parts for his research. PSU 9