Preset control method for thickness flying gauge change of hot-dip zinc coating

Abstract

The invention provides a preset control method for a thickness flying gauge change of a hot-dip zinc coating. The method comprises the following steps: with a strip steel speed, air knife pressure, and a distance between an air knife and the surface of strip steel as main influence factors and by applying a principal component analysis method, building a thickness preset model of the coating by using a least-square fitting algorithm of a log-log space; carrying out long-term self-adaption adjustment and short-term self-adaption adjustment on the thickness of the coating aiming at the effects of a variable speed, a target thickness and a strip steel substrate thickness on the thickness of the coating existing in the flying gauge change process; and carrying out online updating calculation on thickness model parameters of the coating by using a Kalman filtering algorithm and a smooth filtering algorithm in thickness control, so as to improve the preset accuracy of the model parameters. By adopting the preset control method, the control problems of overlarge thickness deviation of the coating and coating thickness detection lag caused by changes of the target thickness of the coating, the strip steel substrate thickness and the strip steel speed are solved; automatic preset control of the thickness of the zinc coating is achieved; the thickness deviation of the zinc coating is reduced; the thickness control accuracy of the zinc coating is improved; zinc consumption is reduced; the galvanization cost is also saved.

Description

Technical field [0001] The invention belongs to the field of automatic control, and in particular relates to a preset control method for dynamically changing specifications of continuous hot-dip galvanizing coating thickness. Background technique [0002] In the entire hot-dip galvanizing production process, the thickness control of the zinc layer is a very important link, and the quality of the control directly affects the quality of the product. Thick coating not only wastes raw materials such as zinc ingots, but also affects the performance of the product; while thin coating will affect the corrosion resistance of the product, which puts forward higher technical requirements and control difficulties for zinc layer thickness control technology . The factors affecting the thickness of the zinc layer are complex, with non-linear, time-varying lag, and multi-variable object characteristics, resulting in low system control accuracy. Especially when the specifications are dynamica...

AI Technical Summary

Problems solved by technology

[0006] The invention provides a method for preset control of hot-dip galvanized coating thickness dynamically variable specifications, the purpose of which is to solve the excessive coating thickness deviation caused by changes in coating target thickness, strip steel substrate thickness and strip speed during the transition process of zinc coating thickness control. Large, and control problems caused by coating thickness detection lag, thereby improving the response speed of the air knife control, effectively suppressing the influence of interference during the galvanizing transition process on the coating thickness, improving the uniformity of the thickness, and reducing the hot-dip galvanized layer. Thickness deviation

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