6533b85cfe1ef96bd12bc6b5

RESEARCH PRODUCT

Path Planning in Inspection Process of 3-D Parts Used the Visibility Technique

subject

description

International audience; In this paper presents a new method for digitalization of parts with non-contact sensor remains nevertheless complex. It is not completely solved today, in particular from a metrological point of view. In this article, we consider the determination of the trajectory planning within the framework of the control of dimensional and geometrical specifications. The sensor used in this application is a laser planner scanner with CCD camera oriented and moved by a CMM. Thus, we seek to determine which are the best possible orientations of the sensor with respect to the geometrical specifications of the measured part, giving the admissible measurement uncertainties. The developed method is based on the concept of visibility. It is declined in successive steps. The first defines the concept of local laser visibility: potential whole of the directions of emission of the laser beam, which reach a particular facet of the part. The directions are constrained by measurement uncertainties depending to the incidence angle between the laser plane (, ) and the measured surface. The second guarantees that a visible facet in certain directions is not hidden by another portion of the part. So this step constitutes the global laser visibility. Lastly, this same facet lit by the laser must also be visible by the camera. The third step thus deals with this problem of screening and determines the chart of real visibility associated to the facet concerned. So, we can generate a 3D map with a set of viewpoints obtained with an optimal distance d in respect to the admissible uncertainties, which permits to cover all the part. This set of viewpoints will be used to propose finally the best scanning path for three-dimensional parts inspection. Some examples illustrate the developed approach.