Measurement of the cross-sectional contour of H-shaped steel using multiple stereo pairs

Measurement of the cross-sectional (CS) contour of H-shaped steel using multiple stereo pairs is studied. Camera modeling and the calibration technique proposed by Zhang (1998) are implemented for such an application. An active approach of using laser light projection on the steel is used. It is advantageous to solve the image correspondence problem and improve the robustness of measurement accuracy. Experimental examples of measuring the CS contour of real H-shaped steel are presented for demonstration. The maximum error of measurement without considering the lens distortion is 2%, while the tolerance accepted by manufacturers is 3%. The results show that the proposed multiple stereo pairs are adequate for the measurement of the CS contour of H-shaped steel