A temperature control method for continuous casting slab induction heating process based on iterative learning control

Abstract

The invention discloses a temperature control method for a continuous casting billet induction heating process, based on iterative learning control. The method comprises the steps that historical process data is preprocessed, and an input and output trajectory of the latest operation process is taken as a reference trajectory; a historical data trajectory subtracts the reference trajectory, a large amount of nonlinearity is removed, and a perturbation model variable is obtained; a revised dataset is processed through the partial least-squares regression method, and a linearized perturbation model around the reference trajectory is obtained; the control input voltage of the operation is calculated according to a learning law of iterative learning control; the control input voltage obtained through calculation is applied to the induction heating process, so that the billet outlet temperature of the process is obtained; newly obtained process data is added into a historical database, an old data is removed, and the next iteration cycle begins. The method sufficiently utilizes the characteristic of the repeatability of the induction heating process, introduces the iterative learning algorithm, and enables an output temperature trajectory to furthest track an expected temperature trajectory.

Description

technical field [0001] The invention belongs to the field of industrial process control, and relates to a temperature control method for continuous casting slab electromagnetic induction heating process, in particular to a temperature control method for induction heating process based on iterative learning control. Background technique [0002] Induction heating technology has the characteristics of low loss, cleanliness, and short heating time, and has been widely used in industrial production, such as metal quenching, preheating, forging, etc. In continuous casting and rolling production, it is often hoped that the heated continuous casting slab has a consistent temperature distribution after heating, which can meet the requirements of subsequent rolling, thereby increasing the yield. The temperature control of the continuous casting slab induction heating has always been a difficult problem. The difficulty lies in: firstly, induction heating is a strongly coupled physica...

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Problems solved by technology

However, the control effect of this control algorithm depends too much on the accuracy of the prediction model. In practice, the simplification of the model and insufficient data preprocessing may lead to low model accuracy. In addition, this control strategy based on offline modeling belongs to open-loop control. Insufficient anti-interference ability of the model

Due to the defects of the above method, it has not been widely used in practice, and many factories still use experience and trial and error methods to control temperature, and the control effect is not good.

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