3D optical measuring of object with grating projecting light pattern on object

摘要

The method involves using measuring system for calibration with measuring field value and once calibrated can then be adjusted for differences also very large measuring distances and volumes. The measuring system must be calibrated with an optical, laminar 3D measuring method. The measuring system includes a projection unit, with a light source (1), a projection grating (2), and an optic (8). Also a camera or a video camera with an optic (9) and an image sensor (6). With an image processing system (7), the imagings of the projected light pattern (3) on the object (4), the surface contour of the object is computed. The geometric characteristic values of the system must be known for carrying out the triangulation computation. After the calibration, the object need not be readjusted. The new method enables the measuring system also after the calibration to be adjusted to another measuring field value, by determining the inner ray beam of the projector and camera using a unit, which simultaneously acts for the focussing to different measuring distances. So that the measuring system to different measuring field values, such that the geometric alterations executed are exactly determinable at the system, and the parameters determining the triangulation can be computed without a new calibration. The calibration results now with a measuring field value, which is selected alone under principles of favorable production of the calibrating system also easily treatable dimensions.