Controlling the part’s balance of crankshafts are important issues for automotive manufacturers. Unbalance measurement is usually carried out using high-precision mechanical machines. The main objective of the present work is to replace mechanical measuring systems by a non-contact digitizing system, which permits the acquisition of the crankshaft surface. As the geometry to be measured presents a large variety of shapes and textures with accessibility issues, the definition of the best-suited scanning system related to geometrical and industrial constraints is a major issue. In this direction, the paper deals with the definition of a protocol based on quality indicators associated to the collected data to compare various digitizing systems. Those quality indicators are assessed thanks to simple artifacts measurement according to a specific procedure. The comparison protocol is applied to evaluate three triangulation based digitizing systems: Results allow us to identify well-adapted digitizing systems in relation to crankshaft balancing requirements.

The paper deals with an original approach to scan path planning that applies for any type of sensors. The approach relies on the representation of the part surface as a voxel map. The size of each voxel is defined according to the sensor FOV. To each voxel, a unique point of view is associated in function of visibility and quality criteria. Whatever the sensor, the method provides a set of admissible points of view to ensure the surface digitizing with a given quality.