Decoupling control of bridle rolls for steel mill drive system

A decoupling controller between the tension and speed of steel a processing line is proposed for bridle rolls of the steel mill drive system. With the controller, the tension of the steel strip is kept as a reference value regardless of the line speed variations and the speed of the strip is also kept regardless of the tension variations. The controller generates a torque reference of each roll driving motor according to the average roll speed and required tension, which is in contrast to conventional controllers where one regulates line speed and the other tension. The effectiveness and the performance of this controller is verified by computer simulation and prototype experiments.