Design and evaluation of an integrated scanning laser triangulation sensor

This work presents the design, simulation, control and experimental result of an optical scanning laser sensor for 3D imaging. The system design satisfies the Scheimpflug condition even though only the illumination path is scanned by a compact fast steering mirror (FSM). To reconstruct the surface profile from measured quantities and model parameters, geometrical relations are used. The influence of a misalignment on the achievable resolution is determined, using ray-tracing simulations. To scan the area of interest an adapted scan trajectory is employed, such that a uniform spatial resolution is generated. The system captures the sample with 100 x 100 pixels and achieves a frametime of 10 s. The lateral scan area of 15 x 23 mm is obtained with a maximum lateral resolution of 60 µm. Through the optical scan the measurement time can be reduced by a factor of 400 compared to a mechanical scanning triangulation sensor system.