Optimal control of strip thickness based on improved fractal prediction
SUN Li-jie
SHAO Cheng
ZHANG Li
Abstract：Aiming at low control accuracy and overshoot oscillation problem of the monitor automatic gauge control (AGC) in hot tandem mill due to time-delay and parameter mismatch problem, firstly, the method of time delay estimation based on the wavelet cross-correlation is proposed to determine the delay step; then, the fractal extrapolation interpolation algorithm is used to give the prediction model considering the time delay, and the vertical scale factor is deduced by using the chaos optimization algorithm; finally, PID controller parameters are optimized by using the ladder type dynamic matrix control (DMC) in order that they are adaptively adjusted according to the different working conditions. Compared with the traditional AGC, Smith-AGC and IFEIP-AGC (improved fracted expolotion prediction, IFEIP), the simulation results show that the proposed method can effectively alleviate control overshoot and oscillation phenomenon of exit strip thickness caused by time delay, and the improved system has better dynamic and static characteristics under the condition of external disturbance and system parameter mismatch.
Keywords：time delay estimationstrip thickness controldynamic matrix controlchaosoptimization
Publication Date：2018-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：10( 822-831 )