The invention provides a method for visually monitoring the radius of an item which is rotating about a fixed axis and which has a trackable contour known to lie in a plane normal to the rotation, such as a part turned on a lathe. The present invention can also estimate the cross-sectional diameter of...http://www.google.com/patents/US5918196?utm_source=gb-gplus-sharePatent US5918196 - Vision system for analyzing solid-of-revolution radius profile
