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.