Development of an Online Warping Detection System for Cold-Rolled Thin Strip Steel

An online warping detection method for cold-rolled thin strip steel has not been previously used in the steel industry. Online warping detection equipment was developed by using a line laser and industrial camera for the first time. Based on digital image processing technology, the relative height distribution of the laser line along the width direction of strip steel was obtained, which could be used to judge the warping degree of the strip steel. A mathematical model of online warping height was established, and the model was validated by laboratory tests. Furthermore, the prediction of offline warping height could be calculated by this model. An online monitoring system of strip warping height was developed, which could monitor the warping height of strip steel in real time. The equipment and system have been successfully installed and applied in a tinning production line. The digitization and traceability of warping defects for a whole coil have been realized, achieving good results.