External excited adaptive QFT tuning for feed-forward AGC systems

Causes for plate thickness variation in the rolling process were analyzed.Uncertain disturbances in the rolling process were attributed to mill stiffness modulus perturbation and stock plastic coefficient perturbation,and then a dual perturbation automatic gauge control(AGC) theory was established.Considering the external disturbances of the rolling mill system,especially uncertainties between passes,the thickness information was converted to boundary specifications in the frequency domain.For disturbance attenuation,a controller based on the external excited adaptive quantitative feedback theory(QFT) was designed with loop shaping.The controller can effectively suppress external disturbances in the rolling process,and has a good robust performance,which can ensure robust stability in system adjustment.The proposed method is suitable for industrial production.