• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.10
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• pp.2629-2639
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• 1994

A robust multivariable controller is synthesized for tandem cold mills. A blocked-noninteracting control method is applied for simplifying the structure of rolling control systems. And, a loop-shaping LQ control method is applied for maintaining the variation of the thickness and tension of each rolling stand as small as possible. In this paper, the effects of the design parameter on loop-shaping and the number of control inputs are evaluated. The simulation results show that the thickness and tension control accuracy of tandem cold mills can be improved by the blocked-noninteracting and compensated loop-shaping LQ controller.

• Journal of the Korean Society for Precision Engineering
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• v.12 no.7
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• pp.114-122
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• 1995

A digital preview controller is designed for tandem cold mills to achieve a more improvement of the thickness accuracy. Simultaneously a blocked noninteracting controller is synthesized for rejecting the interactive effects among adjacent stands and for controlling independently each roll stand of tandem cold mills. The performance effects and characteristics of the suggested roll contol system are discussed in the practical viewpoint. The simulaltion results show that the thickness accuracy of tandem cold mills can be largely improved by the blocked noninteracting and digital preview controller.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.04b
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• pp.293-298
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• 1995

A digital preview controller is designed for tandem cold mills to achieve a better improvement of the thickness accuracy. And simultaneously a blocked noniteracting controller is synthesized for rejecting the interactive effects among adjacent stands and for controlling independently each roll stand of landem cold mills. The performance effects and characteristics of the suggested roll control system are discussed in the practical view points. The simulation results show that the thickness accuracy of tandem cold mills can be largely improved by the blocked noninteracting and digital preview contoller.

• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.9
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• pp.2142-2153
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• 1995

A digital preview controller using optimal LQ control theory is suggested for tandem cold mills to achieve a remarkable improvement of the thickness accuracy. Optimal preview control system is constructed for each rolling stand of tandem cold mills for which the blocked noninteracting control is carried out, and it is compared with the optimal LQ control system which has only feedback control. And in the cases that all/some of disturbance inputs are previewable, full and partial preview controllers are designed, and their performance effects are compared and discussed. The simulation results show that the performance of tandem cold mills can be improved largely through partial preview control.