A method for detecting the camber of plates based on machine vision

Abstract

The invention particularly relates to a method for detecting the camber of plates based on machine vision, belonging to the automatic control field of steel rolling processes. The method comprises thefollowing steps: obtaining plate images through plane array CCD cameras installed right above a roller way outside of roller beds in front of and behind a rolling mill, and correcting the distortionof the images through camera calibration; performing Gaussian low-pass frequency domain filtering on the corrected images, and performing image sharpening differential operation on the filtered imagesto enhance the image boundary. Mathematical morphology transformation and threshold binarization are carried out on the images with enhanced boundaries to segment and completely extract the plate image. The pixel coordinates of the edge contour points are extracted by using the Canny edge detection operator after threshold segmentation and the sub-pixel coordinates of the plate edges are obtained by using the improved Zernike orthogonal moment sub-pixel edge detection algorithm, and the camber value is obtained by fitting.

Description

technical field [0001] The invention belongs to the field of automatic control of steel rolling process, and in particular relates to a method for detecting camber of a plate based on machine vision. Background technique [0002] In the conventional plate and strip rolling production process, due to the influence of rolling equipment and rolling process and other factors, the sickle defect of the plate often occurs. The root cause is the wedge shape of the entrance rolling piece, uneven temperature on both sides of the entrance rolling piece Asymmetric factors such as deviation, different longitudinal rigidity on both sides of the rolling mill, and roll inclination lead to asymmetrical rolling state of the rolled piece, resulting in asymmetrical longitudinal extension of each point in the transverse direction of the rolled piece, making the exit of the rolled piece at the exit section of the deformation zone The speed is asymmetrical along the lateral direction, forming a ca...

AI Technical Summary

Problems solved by technology

[0003] At present, most plate rolling production lines mainly detect camber with naked eyes. This method is too dependent on the working experience of the staff, which is relatively low in efficiency and accuracy, and cannot accurately calculate the camber The existing technology includes the following types: 1) Combine the laser instrument and the width measuring instrument, and calculate the curvature of the slab by measuring the distance from the side of the slab. This method requires a large thickness of the slab and is easy to Affected by the on-site rolling environment; 2) Obtain steel plate images through industrial cameras and use polynomial fitting method to calculate edge sub-pixel coordinates. This method has low recognition accuracy and poor anti-interference ability, and can only be applied to scenes with low noise. Deviation, vibration, etc. are common in the production process; 3) Introduce the thickness factor of the intermediate billet, and use the traversal algorithm to find the starting point and end point of the edge contour. Low recognition accuracy

Images