Study Of Plate Shape Inspection Method For Reversible Cold Rolled Mill

With the progress of science and technology,cold rolled steel strip is playing an increasingly important role in people’s lives,and its demand is growing rapidly,and the majority of users have higher and higher requirements for the quality of its raw materials.However,in the real productive processes,the plate shape problem has been one of the field problems plaguing enterprises,often due to bad plate leading to bad grade products,bringing serious economic losses to enterprises,so online surface inspection is of great significance to improve the quality of strip steel.In this paper,an auxiliary laser line based plate shape detection method is used,the single camera and dual camera detection methods are investigated separately.In the single camera processing method,the camera and laser are installed at a suitable location near the mill so that the line laser can shine on the width direction of the strip and the video is captured back through the camera.To facilitate processing,the image is first rotated so that the line laser can be vertical,and then the line laser part is extracted separately,after which the region of interest is filtered,and after comparing several filtering methods,bilateral Gaussian filtering is selected;then image enhancement is performed,and by comparing three methods,the contrast-constrained adaptive histogram equalization is finally selected;edge detection is performed on the image after image enhancement The upper part of the laser line was found to be missing,and the problem was solved by normalization and binarization with Otsu method.The upper and lower edges of the strip;further the extraction of the center of the line structure light,by comparing several methods,finally choose the center of gravity extraction method based on contour tracking.After that,when the plate shape is good,the line structure light center is extracted and a standard laser line is calibrated,and the difference between the detection laser line and the standard laser line is used to reflect the cross-sectional curve of the strip and the final plate shape information,and several sets of comparisons are made with the actual defects in the field.In order to calculate the accuracy,an experimental platform is set up in the laboratory to simulate the field and calculate the accuracy of the strip shape under a single camera.In order to improve the accuracy,experiments were conducted using double cameras based on the single camera,with different angles of the root drama,so that the upper camera could capture the upper part of the laser line and the lower camera could capture the lower part of the laser line,and image processing was performed separately,and the data from the two cameras obtained from the final processing were fused to make them display the complete laser line data,and the accuracy of the dual camera was calculated to be higher than that of the single camera.Finally,the experimental device of the dual camera was installed in the field for debugging and several sets of defects were compared,and the system has been tested on the No.3 rolling mill of Zhejiang Huada for plate shape inspection.