Rotationally Symmetric Triangulation Sensor with Integrated Vision System

Abstract

This article deals with a novel type of rotationally symmetric triangulation sensor for optical distance measurement and with an integrated vision system to capture an image of the measurement object. The new sensor is equipped with only one optical system containing multifunctional elements and only one 2D detector for both purposes: for rotationally symmetric triangulation and for imaging the object. Thus the sensor is obtaining two types of information with a single system. Thereby the optical surfaces of the distance measurement system depend on toroidal optical surfaces and the optical surfaces of the vision system are located in the inner area of the toroidal surfaces. This results in multifunctional optical elements which can be manufactured by diamond turning or by low cost injection molding.

A Laser Triangulation Displacement Sensor Based on a Cylindrical Annular Reflector

“…[14,15]. To reduce the volume and weight of optical systems, Eckstein J [16,17] separately designed few rotational symmetric optical layouts using 1 to 4 refracting surfaces, and one kind of layout with two circular confocal lenses was finally put forward called RSTS-PRO. The minimum resolution of this sensor can be 0.3 µm, but this structure has high requirements for the design of refractive surfaces.…”