Advanced A. G. C. System for Cold Tandem Mill Based on ILQ Design Theory

Nonlinear Receding Horizon Control of Thickness and Tension in a Tandem Cold Mill with a Variable Rolling Speed

“…The state equation of a controlled system is given by ......................... (1) where denotes an -dimensional vector-valued function. Moreover, constraints on the state and input are expressed as the following equality constraint: ......................... (2) where denotes an -dimensional vector-valued function. An inequality constraint can be converted into an equality constraint by introducing a dummy variable.…”

“…Conventionally, in steady-state high-speed rolling, the tandem cold mill is controlled using an approximate linear model of rolling. 1,2) However, when the rolling speed changes rapidly, such as during periods of acceleration and deceleration, the effect of nonlinear dynamics, which has an undesirable influence on thickness and tension control, is not negligible, and the linearized model is often inaccurate, resulting in variations in quality. Although a method of determining gains based on a transfer function model depending on the rolling speed has been proposed, 3) the transfer function used was essentially a linear model under the assumption of a constant rolling speed, and a rapid change in the rolling speed inevitably deteriorated the control performance.…”

Mill-balance Control Technique for Tandem Cold Mill.

“…[1][2][3] Specifically, the setup control determines the aim gages and the aim tensions using the setup model prior to the rolling. And in the rolling, the AGC regulates the stand exit gages at aim gages.…”