Object locating system

Abstract

The invention projects a known geometry light source onto the surface of an object. A camera with a known distance and angular orientation with respect to the light source is used to capture the light source image on the object. The normal to the surface of the object is determined from the known size of the projected image, the angles of the intersecting lines in the projected image and the corresponding values in the received image. If a hole is to be located, the image projected is a cross and the center of the hole is determined by finding the end points of image line segments which correspond to hole edges. The center and surface normal define the location and orientation of the hole. The surface normal and the center of the hole are transformed into a robot coordinate system and a robot can be commanded to insert a bolt into the hole based on the values. The system can be used to map and measure a surface contour by determining normals and intersection points along the contour, calculating the distances between intersection points and summing these distances. Relative angles between surfaces can be determined from the normals. An object can be identified by comparing the relative angles between the surfaces of the object to relative angles for known reference objects. A Gaussian image can be produced by taking normals over the surface of the object and plotting these in a spherical coordinate system and used for object identification.