DETECTION OF THE SPATIAL STRUCTURE OF A THREE-DIMENSIONAL SURFACE

摘要

The present invention concerns a process for detecting the spatial structure of a three-dimensional surface by projection of a pattern on to the surface along a projection direction which defines a first axis, and by pixel-wise detection of at least one region of the pattern projected on to the surface, by means of one or more sensors in a viewing direction of the sensor or sensors, which defines a second axis, wherein the first and the second axes (or a straight line parallel to the second axis) intersect at an angle different from 0° so that the first and the second axes (or the straight line parallel thereto) define a triangulation plane, wherein the pattern is defined at least upon projection into a plane perpendicularly to the first axis by a varying physical parameter which can be detected by the sensor (sensors), and wherein the pattern is such that the difference in the physically measurable parameter, measured between predeterminable image pixels or pixel groups, along a predeterminable pixel row which is preferably parallel to the triangulation plane, assumes at least two different values. In order to provide a process for detecting the spatial structure of a three-dimensional surface, which is substantially independent of different inclinations with respect to a normal to the triangulation plane and also independent of the other surface properties which independently of the spatial extent of the surface can influence the physical parameter to be measured, in accordance with the invention it is proposed that, for the purposes of evaluation of the imaged pattern structure only changes in the physical parameter between the predetermined pixels or predetermined pixel groups of one or more pixel rows which are preferably parallel to the triangulation plane are detected and converted into spatial co-ordinates of the surface.