A novel moiré-based optical scanning head for high-precision contouring

This paper is devoted to the design and implementation of a novel moir,-based optical head mounted on the robotic arm of a coordinate measuring machine. The optical components of the recently developed two-projector moir, setup were miniaturized and integrated in the optical head. Special care was taken in minimizing the weight of the resulting structure so as to reduce as much as possible the forces acting on the robotic arm. The prototype of the optical head was tested by contouring the shape of different objects and measuring the displacements of a metallic bar subjected to compression loading. Measurements conducted with the proposed optical head were consistent with those obtained via a coordinate measuring machine (CMM). The values of the dimensions found fell always within the average +/- standard deviation interval measured with the CMM. The optical head appears very suited for contouring the shape of objects and for determining the out-of-plane displacement field of mechanical components subjected to specific boundary and loading conditions. Furthermore, the system can be easily implemented inline in an industrial context to perform measurements as a product is being manufactured.