An advanced rangefinder equipped with a new image sensor with the ability to detect the incident angle of a light stripe

Abstract

This paper describes an advanced rangefinder equipped with a new image sensor capable of detecting the incident angle of a light stripe. The triangulation-based rangefinding approach is the one that is most widely used. However, ordinary triangulation-based rangefinders have hitherto been limited to measuring Lambertian objects because triangulation-based approaches are particularly susceptible to the object's surface reflectivity. We previously proposed a new type of rangefinder that relaxed the above-mentioned restrictions on ordinary rangefinders. However, the previous rangefinder had two unsolved problems: the image sensor used for the rangefinder was one-dimensional, and the experimental verification of the applied object was limited to specular objects and Lambertian objects. We here propose a rangefinder with an area image sensor, extending the capabilities of our previous sensor, which is capable of detecting the two-dimensional incident position and angle of incident light. We have made a prototype rangefinder, and experimentally compared it to our previous rangefinder and to a conventional rangefinder. The experimental results of the proposed rangefinder demonstrate that it measures three-dimensional (3D) shapes objects faster than the previous rangefinder and produces the same high level of accuracy in measuring 3D shapes regardless of the surface reflectance of the given objects.