Study on CCD laser scanning flatness measurement method for hot rolled strip

Abstract

To provide a flexible calibration method and make an accurate machine vision (MV) based flatness measurement strategy a reality in routine production line, an area scan charge coupled device (CCD) laser stripe scanning approach is presented. The applicability of the proposed method is not tied to the strip exclusively. First, we devise an automatic laser stripe imaging quality evaluation method through analysing the characteristics of the image grey gradient of laser stripe, which is a prerequisite for precisely extracting the laser stripe modulated information in hot or reflective object surface; second, a fast system calibration method is designed based on the area scan CCD imaging principle and spatial measurement technologies; here, the practical calibration is an indispensable technique for MV based measurement with large field of view in modern steelmaking lines. The proposed method performs competitively with the state-of-the-art as seen from the comparison of the experimental results. Through online testing, this method also showed considerable promise for hot rolled strip flatness measurement. However, the scheme for eliminating the influence of vibrations related to different applications is not taken into account in the current work.

Digital-Twin-Based Monitoring System for Slab Production Process

“…Liu et al [32] proposed a method based on flame image processing and pattern classification for end-point prediction in the basic oxygen furnace (BOF). Zhao et al [33] suggested a method using region-scanning charge-coupled device (CCD) laser stripe scanning to measure large field-of-view visualizations based on MV in modern steel production lines. Additionally, scholars have discussed the application of intelligent logistics systems to achieve accurate tracking and optimization of raw materials, thereby reducing costs and improving production efficiency [34,35].…”

Research and Development of a Multi-Point High-Precision Displacement Measuring System for the Installation Space of Vibration Isolation on Submarine Raft Structures

“…Another flatness measuring method is to use a CCD (charge coupled device) camera as a data acquisition instrument and to process the acquired image data to obtain the flatness. The data processing process is relatively complex [12]. Furthermore, an instrument developed based on the laser ranging method [13] is also an option.…”

A double laser filtering approach to vibration noise rejection for hot-rolled strip flatness measurement

“…Especially in hot-rolled strip flatness measurement system, the measurement error is related to the process signal. When the vibration signal caused by the movement of hot-rolled strip is independent of the system, it can be considered as white Gaussian noise [16]. But it will lead to measurement error, when we get it by the system.…”