Tail crash control in hot strip mill by LQR

This paper proposes a modified linear model for the snake motion in the hot strip rolling, and the tail crash control by the optimal regulator is considered. First, a good linear model for the snake motion is provided by introducing some parameters to conventional equations. Next, the state-space model is derived from the obtained linear model, and the optimal regulator is designed. It is assumed that only the pressure difference and the leveling gap can be measured by sensors, and thus, an observer is used to estimate the off-center value and its differentiation. The dynamic simulation based on the generalized 2-dimensional theory is used for adjusting parameters and for the control system design, instead of the experiment using actual plant. The effectiveness of the proposed method is demonstrated by numerical experiments of the hot strip rolling by a six-high mill.