Characteristic analysis and optimal control of the thickness and tension system on tandem cold rolling

The tandem cold-rolling process is a multivariable, nonlinear, and strongly coupled complex control procedure, in which the key technologies of automatic gauge control (AGC) and automatic tension control (ATC) are extremely comprehensive, and high precision is required. This paper analyzes the rolling characteristics of tandem cold-rolling process and proposes an innovative multivariable optimization strategy based on inverse linear quadratic (ILQ) optimal control theory for thickness and tension control. First, a new state space model of the tandem cold-rolling process was introduced and verified based on the basic equations of rolling technology and field data. Then, meaningful influence rules on the complex rolling process were obtained by analyzing rolling characteristics. For the complex rolling process, a novel ILQ control strategy was introduced into the thickness and tension control system. As a result, by a series of experiments, the effect of disturbance on the thickness and tension was attenuated to an arbitrary degree of accuracy through the proposed control strategy. Simulation results showed the excellent control performance of the proposed ILQ control strategy compared with the conventional proportion and integration (PI) control strategy.

[1]  Kimura Yukio,et al.  Influence of Plate-out Oil Film on Lubrication Characteristics in Cold Rolling , 2012 .

[2]  Akira Kitamura,et al.  Nonlinear receding horizon control of a tandem cold mill in acceleration and deceleration conditions , 2009, 2009 ICCAS-SICE.

[3]  Kimura Yukio,et al.  Analysis of Chatter in Tandem Cold Rolling Mills , 2003 .

[4]  M. Poursina,et al.  A new method for prediction of forward slip in the tandem cold rolling mill , 2015 .

[5]  Yosuke Amanuma,et al.  Dynamic control of lubrication characteristics in high speed tandem cold rolling , 2016 .

[6]  Manfred Morari,et al.  Interaction measure of tension-thickness control in tandem cold rolling , 1998 .

[7]  G. W. Rigler,et al.  Improved rolling mill automation by means of advanced control techniques and dynamic simulation , 1994, Proceedings of 1994 IEEE Industry Applications Society Annual Meeting.

[8]  Marwan A. Simaan,et al.  Optimal Control of Tandem Cold Rolling Using A Pointwise Linear Quadratic Technique With Trims , 2008 .

[9]  Remn-Min Guo.  EVALUATION OF DYNAMIC CHARACTERISTICS OF HAGC SYSTEM , 1991 .

[10]  I. Postlethwaite,et al.  Multivariable control of a high performance tandem cold rolling mill , 1994 .

[11]  Jie Sun,et al.  Modeling and Analysis of Interstand Tension Control in 6-high Tandem Cold Rolling Mill , 2014 .

[12]  Carlos Thadeu de Ávila Pires,et al.  Set-up optimization for tandem cold mills: A case study , 2006 .

[13]  He-nan Bu,et al.  A novel approach to improve the computing accuracy of rolling force and forward slip , 2019 .

[14]  Xiaofeng Zhang,et al.  Gauge and tension control in unsteady state of cold rolling using mixed H2/H∞ control , 2009, 2009 IEEE International Conference on Control and Automation.

[15]  Ian Postlethwaite,et al.  Improvements in product quality in tandem cold rolling using robust multivariable control , 1998, IEEE Trans. Control. Syst. Technol..

[16]  N. Venkata Reddy,et al.  A set-up model for tandem cold rolling mills , 2001 .

[17]  Semyon M. Meerkov,et al.  An LQR/LQG theory for systems with saturating actuators , 2001, IEEE Trans. Autom. Control..

[18]  Erik Dahlquist,et al.  Multivariable data analysis of a cold rolling control system to minimise defects , 2011 .

[19]  M.A. Simaan,et al.  A Novel Approach for Optimal Control of Continuous Tandem Cold Metal Rolling , 2007, 2007 IEEE Industry Applications Annual Meeting.

[20]  H. Abou-Kandil,et al.  Matrix Riccati Equations in Control and Systems Theory , 2003, IEEE Transactions on Automatic Control.

[21]  T. Fujii,et al.  A new approach to the LQ design from the viewpoint of the inverse regulator problem , 1987 .

[22]  Y. Kadoya,et al.  Strip gage and tension control at cold tandem mill based on ILQ design theory , 1999, Proceedings of the 1999 IEEE International Conference on Control Applications (Cat. No.99CH36328).

[23]  Erik Dahlquist,et al.  Adaptive control of cold rolling system in electrical strips production system with online-offline predictors , 2010 .

[24]  Debasish Ghose,et al.  State-Dependent Riccati-Equation-Based Guidance Law for Impact-Angle-Constrained Trajectories , 2009 .