A Useful Control Model for Tandem Hot Metal Strip Rolling

The tandem hot metal strip rolling process is a highly complex nonlinear system that presents a difficult control challenge. This challenge is exacerbated by the hostile hot metal rolling environment, which precludes the location of sensors to measure variables that are important for control. In addition, the controller must have a structure that offers simplicity of tuning during commissioning by personnel who usually are unfamiliar with advanced process control techniques. Based on our previous work using a state-dependent Riccati equation technique for control of the tandem cold metal rolling process, it is considered that a similar method might also be useful for control of tandem hot strip rolling. For the hot rolling process, the development of a process model in a form that is suitable for control development is a significant and challenging task. This paper describes our work to expand on an initial portion of this model to develop a comprehensive nonlinear model of this process. Based on simulation results, it is determined that the complete model has the potential to be useful in the development of a viable nonlinear control method for significant improvement in the control of the tandem hot rolling process.