A Feedforward Compensation Method and System for Entrance Tension under Second Flow Thickness Control

Abstract

The invention provides a feedforward compensation method for inlet tension through design flow and thickness control. The strip steel inlet thickness measured through an inlet thickness measurer is delayed to the rolling machine roller gap position; the strip steel outlet thickness value is pre-calculated according to the design flow equation; according to the error between the strip steel outletthickness value and the outlet thickness set value, the design flow AGC speed compensation amount within a sampling period is solved; according to the design flow AGC speed compensation amount withineach sampling period, the design flow AGC speed compensation amount is obtained through a proportional-integral controller; the speed compensating amount is converted into the acceleration compensation amount through the differentiation element; the first-order lag link is used for smooth processing of the acceleration compensation amount and amplitude limiting, the accelerating torque compensation amount of an inlet rolling machine is obtained through conversion, and feedforward compensation for the inlet tension is achieved during design flow AGC enabling. According to the feedforward compensation method, the strong coupling relation between the design flow AGC and inlet tension control is weakened, accordingly, integral thickness control and tension control precision is improved, and the yield is increased.

Description

technical field [0001] The invention belongs to the field of rolling mill control, and in particular relates to a feedforward compensation method and system for inlet tension by second flow thickness control. Background technique [0002] The cold rolling mill is a process in which the uncoiler, steering roll, rolling mill frame and coiler are all mechanically connected into a whole through the rolled strip to form a tension rolling process. Therefore, rolling tension is a very important parameter in the strip production process and must be strictly controlled. At the same time, strip thickness is the most important indicator of product quality, so thickness control and tension control systems are indispensable and important components in the electronic control system of modern cold rolling mills. [0003] The thickness control system of a single-stand reversing cold rolling mill generally includes three automatic gauge control methods: feedforward, second flow, and monitor...

AI Technical Summary

Problems solved by technology

Obviously, there is a strong coupling relationship between thickness control and tension control. If no compensation is made, the out-of-tolerance length of the strip will be greatly increased, and the product yield will decrease, resulting in great waste and cost increase.

[0008] At present, the decoupling control methods of rolling mill thickness and tension are mostly concentrated on theoretical research, and some literatures use intelligent decoupling control methods, such as recurrent neural network, multivariable robust decoupling control, etc. Most of the papers are proved by simulation experiments its effectiveness, however, considering the complexity of these intelligent decoupling algorithms, it is difficult to apply in practice

There is also a diagonal matrix decoupling control method to solve this problem, and it has been used on some units, but this method requires a more accurate system transfer function model, and the actual complex system is often time-varying nonlinear, this method The control accuracy will be greatly affected

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