Metal plate strip cold continuous rolling anti-saturation and thickness control method

Abstract

The invention provides a metal plate strip cold continuous rolling anti-saturation and thickness control method. The method comprises the steps that output of a feedback AGC controller and output of afeedback AGC actuator are compared in real time, whether the actuator is in a saturated state or not and whether an anti-saturation control link needs to participate in or not are accurately judged,wherein when the actuator is not in the saturated state, the output of the actuator is completely equal to the output of the controller, and the anti-saturation control link does not participate in the thickness control, and when the actuator is saturated, the output of the controller cannot be completely output by the actuator, the portion, which is not output by the actuator, of the controller output will be converted to anti-saturation control link output, and the anti-saturation control link participates in the thickness control. According to the method, compensation is carried out specially on a special state when the actuator appears to be saturated during feedback AGC, so that the thickness fluctuation is avoided when the feedback AGC actuator is saturated, and then the quality of cold continuous rolled products is improved.

Description

technical field [0001] The invention belongs to the technical field of automatic control of rolling of metal plates and strips, and in particular relates to a method for controlling the anti-saturation thickness of cold continuous rolling of metal plates and strips. Background technique [0002] In the process of continuous cold rolling of metal sheets and strips, the most commonly used thickness control method is to perform feedback control on the thickness of the rolled piece rolled out of the current stand to ensure the thickness accuracy of the finished product. This thickness control method is called feedback AGC. Feedback AGC for continuous cold rolling of plates and strips usually uses the main drive system of the rolling mill as the actuator to adjust the speed difference between the upstream stands to eliminate the thickness deviation rolled out by the current stand. figure 1 is the control block diagram of the feedback AGC, h* is the set value of the rolling thickn...

AI Technical Summary

Problems solved by technology

However, the adjustable range of the actuator to the speed difference between the upstream racks is limited, that is, the output u of the actuator s is limited

When the rolling time of the rolling mill is too long in the low-speed stage, it often causes the output of the actuator to saturate (such as figure 1 shown in the dotted line box), that is, the adjustment value output by the controller cannot be fully implemented, and the output u of the feedback AGC controller at this time n with the output u of the actuator s Not equal, lead to the deterioration of the feedback AGC performance, and then lead to thickness fluctuations, seriously endangering the quality of cold rolling products

[0003] However, in the continuous cold rolling production of metal sheets and strips, when encountering problems such as insufficient loops at the entrance, poor shape of the rolled piece, and cracked edges of the rolled piece, the rolling mill has to be in the low-speed stage for a long time, and the above-mentioned problems are prone to occur. Feedback AGC actuator output saturation phenomenon, resulting in fluctuations in the thickness of the rolled piece, greatly reducing the thickness and quality of cold rolling products

So far, there is still a lack of practical feedback AGC anti-saturation control method

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