On-line closed-loop control method for hot strip flatness

Abstract

The invention relates to an online closed-loop control method for the flatness of hot continuous rolling strips, belonging to the technical field of electric automation control. The method executes the following steps: 1) When the strip arrives at the entrance of the finishing mill, the corresponding value is received; 2) Each frame is closed-loop controlled with the set value of bending force and speed to thread the strip; 3) The final machine is turned off 4) Calculate the time T; 5) Send the feedback value to the automatic control system; 6) According to the feedback value of strip flatness, flatness target value, flatness and bending force The conversion coefficient is used to calculate the size of the bending force of the end frame that needs to be adjusted; 7) The time T is the cycle to continuously read the feedback value, and the calculated adjustment value is used for accumulative control; 8) When the end frame throws steel, the end frame The calculation of the adjustment value of the bending force is completed, and the accumulated value is cleared. The method realizes the closed-loop adjustment of the bending force of the final frame according to the deviation of the flatness of the strip, greatly improves the control precision of the flatness of the strip, and improves the product quality.

Description

technical field [0001] The invention relates to an online closed-loop control method for the flatness of hot continuous rolling strips, belonging to the technical field of electric automation control. Background technique [0002] With the demand of the market, in order to achieve profitability, hot-rolled enterprises continue to expand their products to high-end products, and the precision of product quality control is getting higher and higher. In addition to the previously concerned thickness and width control precision, the flatness control precision of hot-rolled products is also The requirements are very strict, especially for high-end products such as automotive panels. In addition to the high overall control accuracy of the product, it also requires high homogeneity of the product under the premise of high overall control accuracy, that is, the smaller the control accuracy fluctuation, the better. . However, at present, the flatness control of the strip in hot rolli...

AI Technical Summary

Problems solved by technology

For the same piece of steel, the model sets the bending force of the finishing stand once, and will not change during the rolling process. The change of the rolling force of the stand during the manufacturing process makes certain adjustments to the bending force. It is not based on the actual detected flatness of the strip as a reference. Practice has proved that this shape maintaining function can adjust the bending force. Compared with the flatness control effect of the strip, even if the bending force set by the model makes the flatness accuracy of the strip head very good, in the rolling process, due to the temperature and thickness of the strip length direction, etc. Changes in conditions can also cause poor flatness accuracy of the tail in the strip