Control-system synthesis for open-loop unstable process with time delay

To avoid performance limitations caused by an open-loop unstable pole, a three-element structure, which is equivalent to a two-degrees-of-freedom control design, is proposed to synthesise a control system for an open-loop unstable process with time delay. Through this proposed approach, control problems such as stabilising an unstable pole, servo-tracking and disturbance rejection can be treated independently. The resulting three-element structure can then be used to derive conventional two-degrees-of-freedom elements or conventional PID systems. Tuning rules for a PID controller are also provided. Examples are presented to illustrate the proposed method.

[1]  A. T. Shenton,et al.  Tuning of PID-type controllers for stable and unstable systems with time delay , 1994, Autom..

[2]  Brian D. O. Anderson,et al.  Filters for internal model control design for unstable plants , 1993, Proceedings of 32nd IEEE Conference on Decision and Control.

[3]  A. Paor.  A modified Smith predictor and controller for unstable processes with time delay , 1985 .

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

[5]  C. K. Sanathanan,et al.  Controller design for integrating and runaway processes involving time delay , 1989 .

[6]  J. Freudenberg,et al.  Limitations of feedback properties imposed by open-loop right half plane poles , 1991 .

[7]  Chi-Tsong Chen.  Control system design: Conventional, algebraic, and optimal methods , 1987 .

[8]  Bruce A. Francis,et al.  Feedback Control Theory , 1992 .

[9]  Dante C. Youla,et al.  Modern Wiener--Hopf design of optimal controllers Part I: The single-input-output case , 1976 .

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

[11]  M. Chidambaram,et al.  Design of controllers for unstable first-order plus time delay systems , 1996 .

[12]  M. Chidambaram,et al.  Design of P and PI controllers for unstable first-order plus time delay systems , 1994 .

[13]  William L. Luyben,et al.  Process Modeling, Simulation and Control for Chemical Engineers , 1973 .

[14]  M. O'Malley,et al.  Controllers of Ziegler-Nichols type for unstable process with time delay , 1989 .

[15]  D. Lewin,et al.  Simple PI and PID tuning for open-loop unstable systems , 1991 .

[16]  Yuguang Niu,et al.  Tuning of PID controller for unstable process , 1999, Proceedings of the 1999 IEEE International Conference on Control Applications (Cat. No.99CH36328).

[17]  D. Looze,et al.  A sensitivity tradeoff for plants with time delay , 1987 .

[18]  Chi-Tsung Huang,et al.  TUNING PID CONTROLLER FOR OPEN-LOOP UNSTABLE PROCESSES WITH TIME DELAY , 1995 .

[19]  J. Freudenberg,et al.  Right half plane poles and zeros and design tradeoffs in feedback systems , 1985 .

[20]  Benjamin C. Kuo,et al.  AUTOMATIC CONTROL SYSTEMS , 1962, Universum:Technical sciences.