Evaluation of surface roughness by vision system

Conventional measurement of finish using stylus instruments has been in vogue for over half a century. Though these instruments have excellent capabilities and wide range, they are normally used for inspecting machined surfaces of good finish. Further the procedure is a post process approach which is not amenable for automation. In the recent past, higher levels of automation in the shop floor has focused the attention on the application of fast, reliable and cost effective procedures for evaluating surfaces of medium finished parts. This paper deals with the possibility of doing this using a vision system. It briefly reviews a few approaches and examines one - texture unit spectra - in more detail. (C) 1998 Elsevier Science Ltd.