Automatic measurement of the mechanical part based on binocular stereo vision

Based on binocular stereo vision, a method which can automatically measure the distance between two holes on the mechanical part was proposed in order to improve the precision of the traditional measurement. Binocular vision sensor was calibrated; the edge of mechanical part was measured by using canny operator, the region of the hole was recognised by the function, the targets center was detected by using least square fitting method; the automatic stereo matching between two images was come true by the epipolar-slope constraint; the 3D coordinate of each hole was reconstructed and the distance was calculated. The experimental results proves that the measurement of the distance is high accurate, the system error is less than 0.06 mm, which can reach the requirement of online measurement precision.