Non-interactive control for hot rolling mill using nonlinear disturbance observer

This paper proposes an advanced method to reduce fluctuations of strip tension and looper position in a steel rolling mill. We design a non-interactive controller to decouple the looper system into two subsystems. However, these subsystems have uncertainties, disturbances and interactions with each other. In this paper we consider these uncertainties, disturbances and interactions as each nominal subsystem´s disturbance. To reduce these disturbances, we use a nonlinear disturbance observer. In comparison with other methods, the proposed method reduces response time and fluctuations in strip tension. This means that the proposed method can improve the quality of the hot strip finishing mill in the steel making process.