/spl Hscr//sub /spl infin// robustification of a paper machine cross-directional control system

This paper considers /spl Hscr//sub /spl infin// robustification of an industrial paper machine cross-directional (CD) control system. The existing industrial controller is reinterpreted as a precompensator weight for shaping the open-loop response. The robustification is then achieved by performing a robust stabilization of the nominal plant model and industrial controller combination. The large scale (226 inputs and 226 outputs) /spl Hscr//sub /spl infin//. optimization problem is decoupled into 226 independent SISO systems by an application of recent results for spatially invariant systems. The robustified closed-loop is then implemented by augmenting the industrial controller with a low-order prefilter. It is then demonstrated that the robustness of the closed-loop system has been significantly improved while its performance remains well-preserved.

[1]  Sigurd Skogestad,et al.  Control of symmetrically interconnected plants , 1994, Autom..

[2]  Dimitry Gorinevsky,et al.  An experimental demonstration of recent results for spatially distributed control systems , 2001, Proceedings of the 2001 American Control Conference. (Cat. No.01CH37148).

[3]  R. Brockett,et al.  Discretized partial differential equations: Examples of control systems defined on modules , 1974, Autom..

[4]  Dimitry Gorinevsky,et al.  H/sub 2/ loopshaping controller design for spatially distributed systems , 1999, Proceedings of the 38th IEEE Conference on Decision and Control (Cat. No.99CH36304).

[5]  S. R. Duncan.  The design of robust cross-directional control systems for paper making , 1995, Proceedings of 1995 American Control Conference - ACC'95.

[6]  M. Kean,et al.  New algorithms for intelligent identification of paper alignment and nonlinear shrinkage , 1997 .

[7]  Keith Glover,et al.  A loop-shaping design procedure using H/sub infinity / synthesis , 1992 .

[8]  V. Observation Coefficient,et al.  Comments on "Robust, Fragile, or Optimal?" , 1998 .

[9]  Ian Postlethwaite,et al.  Multivariable Feedback Control: Analysis and Design , 1996 .

[10]  Richard D. Braatz,et al.  Robust cross-directional control of large scale paper machines , 1996, Proceeding of the 1996 IEEE International Conference on Control Applications IEEE International Conference on Control Applications held together with IEEE International Symposium on Intelligent Contro.

[11]  Gregory E. Stewart.  Two dimensional loop shaping controller design for paper machine cross-directional processes , 2000 .

[12]  Keith Glover,et al.  μ-analysis and synthesis toolbox: for use with Matlab, user’s guide version 3 , 1998 .

[13]  Fernando Paganini,et al.  Distributed control of spatially invariant systems , 2002, IEEE Trans. Autom. Control..

[14]  Shankar P. Bhattacharyya,et al.  Comments on "Robust, fragile, or optimal?" [with reply] , 1998, IEEE Trans. Autom. Control..

[15]  Richard D. Braatz,et al.  Robust performance of cross-directional basis-weight control in paper machines , 1993, Autom..

[16]  R. D'Andrea,et al.  A linear matrix inequality approach to decentralized control of distributed parameter systems , 1998, Proceedings of the 1998 American Control Conference. ACC (IEEE Cat. No.98CH36207).

[17]  G. Vinnicombe.  Frequency domain uncertainty and the graph topology , 1993, IEEE Trans. Autom. Control..

[18]  Shankar P. Bhattacharyya,et al.  Robust, fragile or optimal? , 1997, Proceedings of the 1997 American Control Conference (Cat. No.97CH36041).