Design of Two-DOF Optimal Controller for Strip Gage and Tension Control of Cold Tandem Mills Using Reference Shaping Filter and Disturbance Observer

목표치 정형화 및 외란 관측기를 활용한 연속 냉간압연 시스템의 2-자유도 스트립 두께 및 장력 최적 제어기 설계

  • Hong, Wan-Kee (STS Process Research Group, Technical Researcher Laboratories, POSCO) ;
  • Kang, Hyun-Seok (STS Process Research Group, Technical Researcher Laboratories, POSCO) ;
  • Hwang, I-Cheol (Dept. of Mechatronics Engineering, Dongeui Univ.)
  • 홍완기 ((주)POSCO 기술연구원 STS 공정연구그룹) ;
  • 강현석 ((주)POSCO 기술연구원 STS 공정연구그룹) ;
  • 황이철 (동의대학교 메카트로닉스공학과)
  • Received : 2011.10.12
  • Accepted : 2011.11.21
  • Published : 2012.02.01


This paper studies the design of a two-DOF optimal controller for the strip gauge-tension of cold tandem mill processes, that uses a reference shaping filter and a disturbance observer. First, a mathematical model of the strip gauge and tension system is constructed using the gauge meter equation and Hooke's law, respectively. Next, a two-DOF controller considering of a feedforward controller and a feedback controller is designed. The former is based on the reference shaping filter and the disturbance observer, and the latter is based on the ILQ optimal control algorithm. Finally, it is shown through a computer simulation that the proposed optimal controller is able to improve the strip gauge accuracy and the tension variation more than the conventional MV-AGC controller.


Supported by : 동의대학교


  1. Kondo et al., 1989, "Analysis of Dynamic Characteristics and Application of Non-interactive Control of Gauge Control of Reversing Cold Mills," Journal of the Society of Instrument and Control Engineers, Vol. 28, No. 5, pp. 445-452.
  2. Kodaya, Y., Ooi, T., Washikita, Y. and Seki, Y., 1999, "Strip Gauge and Tension Control at Cold Tandem Mill Based on ILQ Design Theory," Proc. of the 1999 IEEE Int. Conf. on Control Application, Hawaii, USA, August 22-27, pp. 23-28.
  3. Kim, J. S., Kim, S. S. and Lee, K. T., 1997, "Digital Predictive Control of Tandem Cold Mills," Trans. of the KSME, Vol. 19, No. 9, pp. 2142-2153.
  4. Kim, J. S. and Kim, S. S., 1997, "Multivariable Control Including a Roll Eccentricity of Tandem Cold Mills," Trans. of the KSME (A), Vol. 21, No. 3, pp. 520-510.
  5. Tsuda, 1992, "PID Control," Jochang Press, pp. 69-106, Japan.
  6. Kimura, H. et. al., 1994, "Robust Control," Corona Publishing Co. Ltd., pp. 109-156, Japan.
  7. Iwai, S. D., 1994, "OBSERVER," Corona Publishing Co. Ltd., pp. 36-43, Japan.