Three dimensional acquisition by inverse raytracing approach for specular objects

Abstract

An appearance inspection is one of the most suitable applications of a laser rangefinder. In such a field, many products are designed by 3-D CAD. Therefore, the appearance inspection of products validates the deviation between the designed 3-D data and the measured 3-D data. There are a lot of products of specular objects with shiny surface such as polished metals and plastic materials. However, conventional triangulation-based rangefinders are known to be difficult to apply to the 3-D shape measurement of such shiny objects. In this study, we propose an advanced laser rangefinder to be able to obtain the 3-D shape of specular objects and apply the rangefinder to an appearance inspection system.