John Pittner

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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(More)
The tandem rolling of hot metal strip presents a significant control challenge because of nonlinearities and process complexities. The challenge is heightened by an extremely hostile environment that precludes the location of sensors to measure process variables that are important for control. In addition, it is essential that the controller structure(More)
—The tandem hot metal strip rolling process presents a difficult control challenge because of its highly complex and nonlinear nature. This challenge is heightened by the hostile hot metal rolling environment which precludes the location of certain sensors to measure variables that are important for control. Based on our previous work using a(More)
The tandem cold rolling of metal strip is a complex nonlinear multivariable process whose optimization presents significant challenges to the control design. Existing systems using the present technology are limited in their capability for improvement in performance and robustness and therefore the need arises for a better approach. It is considered that a(More)
The control of continuous tandem cold rolling of metal strip is similar to the control of stand-alone tandem cold rolling except that additional challenges occur during the passage of the weld, which generally is done at reduced speed. The more significant issues that must be considered are the following: 1) reducing the length of strip near the weld that(More)
Controlling the tandem cold rolling of metal strip is a significant engineering challenge mostly because of the complexity of the interactions between the process variables, the nonlinearities which change with the operating conditions, and the long time delays which change significantly with the mill speed. The present technology is based on methods that(More)
Our previous work has shown that the use of the state-dependent Riccati equation (SDRE) technique as a basis for the development of a suitable controller for the tandem hot metal rolling process has resulted in significant improvements in performance. However the method of setting the controller parameters was left as a part of future efforts. In this paper(More)
The tandem cold rolling of metal strip is a large multiinput-multioutput process that presents a difficult challenge to the control designer because of the following factors: 1) the complex interactions between the process variables; 2) the nonlinearities; and 3) the interstand time delays that change significantly with the mill speed. Control systems using(More)
Previously, it has been shown that a controller based on the use of the state-dependent-Riccati-equation technique has resulted in significant improvements in performance. In our previous work, controller performance under certain disturbances and uncertainties that are considered typical for tandem hot rolling was addressed. While the performance under(More)