Repetitive control is applied here to compensate for roll eccentricity disturbances in thickness control of the cold rolling process. A unique aspect of the process is that the eccentricity disturbance may be from multiple rolls and hence may be composed of multiple periodic components whose periods may not be commensurate, namely, divisible by a common factor an integral number of times. The paper presents a multiple-period repetitive controller structure that can compensate for such a disturbance. The structure proposed is also applicable to other tracking and regulation applications involving multiple periodic signals. Procedures to analyze and design control systems with such a structure, to ensure stability and performance, are presented.

Issue Section:
Technical Papers
Topics:
Cold rolling, Control equipment, Control systems, Design, Signals, Stability
1.
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2.
Bryant, G. F., and Osborn, R., 1973, “Development and Assessment of Roll Force Models,” Chapter 12 in Automation of Tandem Mills, Bryant, G. F., ed., The Iron and Steel Institute.
3.
Cummings, I. G., and Sanders, C., 1973, “On-line Identification of a Tandem Mill,” Chapter 17 in Automation of Tandem Mills, Bryant, G. F., ed., The Iron and Steel Institute.
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Garimella, S. S., 1994, “Application of Repetitive Control and Iterative Learning Control to Cold Rolling Processes,” Ph.D. dissertation, The Ohio State University.
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1988
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33
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Middleton, R. H., and Goodwin, G. C., 1990, “An Industrial Case Study,” Chapter 15 in Digital Control and Estimation, A Unified Approach, Prentice Hall.
9.
Mielnik, E. M., 1991, Metal Working Science and Engineering, McGraw-Hill.
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Morari, M., and Zafiriou, E., 1989, Robust Process Control, Prentice Hall.
11.
Smith
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12.
Srinivasan
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Shaw
F.-R.
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Analysis and Design of Repetitive Control Systems Using the Regeneration Spectrum
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13.
Tlusty
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