Evaluation and redesign of decouplers for TITO processes using relay experiment

In this paper the decoupling control of two-inputs two-outputs (TITO) processes using a simplified dynamic decoupler is considered. A frequency-domain identification technique that uses a relay experiment to estimate a first-order plus dead-time (FOPDT) TITO model is presented. The resulting FOPDT TITO model is accurate around at the frequency of interest and is used to design a simplified decoupler. A new decoupler evaluation and redesign method to reach effective decoupling at the frequency of interest is proposed. Simulation examples are used to illustrate the method.

[1]  William L. Luyben,et al.  Simple method for tuning SISO controllers in multivariable systems , 1986 .

[2]  Chih-Hung Chiang,et al.  A direct method for multi-loop PI/PID controller design , 2003 .

[3]  W. Cai,et al.  Normalized Decoupling —A New Approach for MIMO Process Control System Design , 2008 .

[4]  R. K. Wood,et al.  Terminal composition control of a binary distillation column , 1973 .

[5]  Wang,et al.  Auto-tuning of TITO decoupling controllers from step tests , 2000, ISA transactions.

[6]  Shih‐Haur Shen,et al.  Use of relay‐feedback test for automatic tuning of multivariable systems , 1994 .

[7]  Zalman J. Palmor,et al.  Automatic tuning of decentralized PID controllers for TITO processes , 1993, Autom..

[8]  Zalman J. Palmor,et al.  Automatic Tuning of Decentralized PID Controllers for TITO Processes , 1993 .

[9]  Tore Hägglund,et al.  Advanced PID Control , 2005 .

[10]  Saeed Tavakoli,et al.  Tuning of decentralised PI (PID) controllers for TITO processes , 2006 .

[11]  F. G. Greg Shinskey,et al.  Process Control Systems: Application, Design and Tuning , 1990 .

[12]  Wenjian Cai,et al.  Effective transfer function method for decentralized control system design of multi-input multi-output processes , 2006 .

[13]  W. Cai,et al.  Equivalent transfer function method for PI/PID controller design of MIMO processes , 2007 .

[14]  Wenjian Cai,et al.  Decentralized Control System Design for Multivariable ProcessesA Novel Method Based on Effective Relative Gain Array , 2006 .

[15]  Shyh Hong Hwang,et al.  Sequential design method for multivariable decoupling and multiloop PID controllers , 1998 .