Partial decoupling of non-minimum phase processes with bounds on the remaining coupling

Partial (triangular) decoupling of MIMO systems has been considered in the literature as a way of relaxing the design limitations introduced by diagonal decoupling in non-minimum phase processes. The former strategy allows decoupling a variable of interest without affecting it with non-minimum phase dynamics. However, when right-half plane (RHP) zeros are mainly aligned with this variable, pushing the effect of the RHP zeros to other outputs comes at the cost of great interactions in those variables. This article presents a method to delimit these interactions without degrading significantly the decoupled variable response. To this end, the algorithm shapes the reference signal by means of an auxiliary sliding mode loop.

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

[2]  Chyi-Tsong Chen,et al.  A sliding mode control scheme for non-minimum phase non-linear uncertain input-delay chemical processes , 2006 .

[3]  Qing-Guo Wang,et al.  Decoupling with internal stability for unity output feedback systems , 1992, Autom..

[4]  Graham C. Goodwin,et al.  Controller design for partial decoupling of linear multivariable systems , 1996 .

[5]  Evanghelos Zafiriou,et al.  Robust process control , 1987 .

[6]  Oscar Camacho,et al.  A General Sliding Mode Controller for Nonlinear Chemical , 2000 .

[7]  Guido Herrmann,et al.  A model-based sliding mode control methodology applied to the HDA-plant , 2003 .

[8]  Vadim I. Utkin,et al.  Sliding mode control in electromechanical systems , 1999 .

[9]  Christopher Edwards,et al.  Sliding mode control : theory and applications , 1998 .

[10]  Graham C. Goodwin,et al.  Fundamental Limitations in Filtering and Control , 1997 .

[11]  Graham C. Goodwin,et al.  Cheap decoupled control , 2001, Autom..

[12]  C. Desoer,et al.  Decoupling linear multiinput multioutput plants by dynamic output feedback: An algebraic theory , 1986 .

[13]  Fernando D. Bianchi,et al.  Sliding Mode Conditioning for Constrained Processes , 2004 .

[14]  Chyi-Tsong Chen,et al.  Design of a sliding mode control system for chemical processes , 2005 .

[15]  Hernán De Battista,et al.  VSS global performance improvement based on AW concepts , 2005, Autom..

[16]  Karl Henrik Johansson,et al.  The quadruple-tank process: a multivariable laboratory process with an adjustable zero , 2000, IEEE Trans. Control. Syst. Technol..

[17]  M. Heymann,et al.  Linear feedback decoupling--Transfer function analysis , 1983 .

[18]  Karl Henrik Johansson,et al.  Interaction bounds in multivariable control systems , 1999, Autom..

[19]  A. Isidori.  Nonlinear Control Systems , 1985 .

[20]  V. Eldem.  The solution of diagonal decoupling problem by dynamic output feedback and constant precompensator: the general case , 1994, IEEE Trans. Autom. Control..

[21]  Fotis N. Koumboulis.  Input-output triangular decoupling and data sensitivity , 1996, Autom..

[22]  H. Sira-Ramírez.  Sliding regimes in general non-linear systems: a relative degree approach , 1989 .

[23]  Graham C. Goodwin,et al.  Control System Design , 2000 .

[24]  Fabricio Garelli,et al.  Limiting interactions in decentralized control of MIMO systems , 2006 .

[25]  A. Morse,et al.  Triangular decoupling of linear multivariable systems , 1970 .