Design of Closed Loop Controls for a Seven-Stand Hot Strip Rolling Mill

A hot strip rolling mill is a complex system which requires sophisticated regulations in order to obtain a constant thickness of the strip at the exit of the mill (the screw positions and the roll speeds are the control variables). Here we present new regulations which take in account the temperature measurements at the exit of the roughing mill. The preset values of the control variables are computed before the milling (feed-forward) These values are modified during the milling by a feedback based upon the forces measurements. This type of system which has the same structure as an Automatic Gauge Control (AGC) is easy to implement on the process.