Partial internal model control

Internal model control (IMC) is a well-known and effective control scheme. However, when unstable processes are concerned, the original IMC structure cannot be directly used for control system implementation. In this paper, a new scheme called partial internal model control (PIMC) is proposed, which is capable of controlling both stable and unstable processes. In PIMC, a process model is expressed as the sum of the stable and antistable parts and only the stable part of the process model is used as the internal model. The process stable part is canceled by the internal model and the remaining antistable part is stabilized and controlled with a primary controller, which is usually a PID-type regulator when the antistable part is of a low order. Various properties of a PIMC system such as internal stability and robust stability are analyzed. The design of PIMC is discussed in detail. Various simulation examples are included for illustration and a real-time implementation on a motor system is presented.

[1]  Carlos E. Garcia,et al.  Internal model control. 2. Design procedure for multivariable systems , 1985 .

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

[3]  Kok Kiong Tan,et al.  Automatic tuning of finite spectrum assignment controllers for delay systems , 1995, Autom..

[4]  Chi-Tsong Chen,et al.  Linear System Theory and Design , 1995 .

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

[6]  Gene F. Franklin,et al.  Feedback Control of Dynamic Systems , 1986 .

[7]  G. E. Rotstein,et al.  Control of an Unstable Batch Chemical Reactor , 1992 .

[8]  S. J. Mason.  Feedback Theory-Further Properties of Signal Flow Graphs , 1956, Proceedings of the IRE.

[9]  Qing-Guo Wang,et al.  Towards Minimal-Order Stabilizers for All-Pole Plants , 1996 .

[10]  Tong Heng Lee,et al.  Internal stability of interconnected systems , 1999, IEEE Trans. Autom. Control..

[11]  Etsujiro Shimemura,et al.  Effects of mismatched smith controller on stability in systems with time-delay , 1987, Autom..

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

[13]  Carlos E. Garcia,et al.  Internal model control. A unifying review and some new results , 1982 .

[14]  Tore Hägglund,et al.  Automatic Tuning of Pid Controllers , 1988 .

[15]  M. Morari,et al.  Internal model control: PID controller design , 1986 .

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