A framework for uncertainty propagation in 3D shape measurement using laser triangulation

The analysis of measurement uncertainty is necessary in every measurement process. In this paper, we suggest an approach to categorize and model the dominant sources of uncertainty and study the probabilistic propagation of the uncertainties in a 3D inspection using laser line scanners. To each point of the measurement point cloud, we associate a covariance matrix describing the corresponding dispersion ellipsoid in the 3D space. The uncertainties can be analyzed for each desired laser and camera constellation and thus, the method can be applied in designing and optimizing laser scanner setups, reducing the effort of manually evaluating the setup in a trial and error approach. As a demonstration, the inspection of a cylinder head has been simulated using computer graphics and the estimated uncertainty metrics are visualized on the measured surface.