Abstract: Improved component placement inspection and verification is performed by a pick and place machine. Improvements include stereovision imaging of the intended placement location; enhanced illumination to facilitate the provision of relatively high-power illumination in the restricted space near the placement nozzle(s); optics to allow image acquisition device to view the placement location from an angle relative to a plane of the placement location, thereby reducing the possibility of such images being obstructed by the component; techniques for rapidly acquiring images with commercially available CCD arrays such that acquisition of before and after images does not substantially impact system throughput; and image processing techniques to provide component inspection and verification information.

Abstract: Improved component placement inspection and verification is performed by a pick and place machine. Improvements include stereovision imaging of the intended placement location; enhanced illumination to facilitate the provision of relatively high-power illumination in the restricted space near the placement nozzle(s); optics to allow image acquisition device to view the placement location from an angle relative to a plane of the placement location, thereby reducing the possibility of such images being obstructed by the component; techniques for rapidly acquiring images with commercially available CCD arrays such that acquisition of before and after images does not substantially impact system throughput; and image processing techniques to provide component inspection and verification information.

Abstract: A system for digital image recognition which combines sparse correlation with image pyramiding to reduce the number of pixels used in correlation provides effective recognition of a reference image template without exhaustive correlation of all pixels in the reference image template. An optimal sparse pixel set is selected from the pixels of the reference image template by correlating the reference image template against a search image scene which is to be searched. Such a sparse pixel set includes those pixels which are optimal in defining the correlation sensitive features of the reference image template. By terminating the accumulation of sparse pixels at an optimal point, performance is maximized without compromising accuracy of recognition. The resultant optimal sparse pixel set is then correlated against the pixels in the search image scene through a series of transformations to find a match of the reference image template within the search image scene.

Abstract: A practical vision system for controlling the positioning of a robot arm recognizes and locates objects. The vision system processes binary images, but recognizes objects based on boundary features such as lines, arcs, corners and holes instead of "blob features" such as area and best-fit ellipse. Consequently, the vision system can process two common situations not handled by blob analysis: merged blobs due to touching or overlapping parts and incomplete blobs due to low image contrast. The microprocessor-based system is interfaced to the robot system and can recognize up to five parts per second.