No abstract

Front-end bending is one of the most significant defects of slabs in hot rough rolling. To address the lack of effective methods to detect slab front-end bending in hot rolling, a measurement system based on line structured light vision is proposed in this paper. Line structured light lasers and area-scan cameras are arranged on the supports on both the exit and entrance of a roughing mill. First, the calibration of the measurement system is completed by camera calibration and the random sampling consistency algorithm (RANSAC). Second, multiple region of interest (ROI) grey thresholds and the Steger algorithm are used to realize laser centreline extraction on the surface of a large-scale and high-temperature slab. Last, the actual value of the slab front-end bending are obtained and calculated through coordinate transformation. The proposed measurement system can detect slab front-end bending in real time and the detection error is less than 5 mm.