Non-linear Control in Rolling Mills: A new Perspective

Description

This paper is concerned with the application of modern non-linear control techniques to the thickness control in rolling mills. It turns out that the performance of the closed loop can be significantly improved by taking into account the essential non-linearities of the to-be-controlled plant already in the controller design. These non-linear control strategies totally differ from the common approach of linearizing the non-linear systems around a nomial operating point because, they are not limited to a more or less small neighborhood of the operating point, but are valid all over the operating range. Practically, these non-linear control concepts are a possible answer to the trend of modern rolling mill towards tighter thickness tolerances, thinner final strip thicknesses, faster production rates and shorter off-gauge lengths. However, a straight forward application of the well established non-linear control theory does not always lead to a control concept that is practically feasible. It is rather unavoidable to consider all the special features and properties of the plant. By means of the gap control of a mill stand with a hydraulic positioning system we wil show in detail the advantages of a non-linear control approach. Finally, simulation and measurement results will demonstrate the feasibility and the excellent performance of the proposed design.

Period	08 Oct 2000
Event title	IEEE IAS Conference and Annual Meeting 2000
Event type	Conference
Location	ItalyShow on map