Regarding self-tuning controllers for nonminimum phase plants

✍ Scribed by G.I. Voss; H.J. Chizeck; P.G. Katona

• Publisher: Elsevier Science
• Year: 1987
• Tongue: English
• Weight: 349 KB
• Volume: 23
• Category: Article
• ISSN: 0005-1098
• DOI: 10.1016/0005-1098(87)90015-x

✦ Synopsis

This correspondence is in response to the recent excellent survey of Clarke (1984, Autoraatica, 20, 501-517), which points out that minimum variance self-tuning controllers fail in the control of nonminimum-phase plants. It is also in response to recent algorithms of Ydstie (1984, Preprints 9th IFAC World Congress, Budapest) which have application in the control of such systems. A new control algorithm, designed to control nonminimum-phase plants, is described here. This ~Control Advance Moving Average Controller" (CAMAC) determines the input that minimizes the variance between the output and the setpoint at a time advance equal to or greater than the input-output (I/O) transport delay, based upon an assumption made on future inputs. The CAMAC algorithm is tuned by determining the appropriate control time advance. This approach is similar to that of Ydstie (1984, Preprints 9th IFAC World Congress, Budapest), but uses a different assumption on future inputs which yields substantially different controller performance. Its performance (in simulation) compares very favorably with that of self-tuning control algorithms reviewed in Clarke (1984, Automatica 20, 501-517) and those described in Ydstie (1984, Preprints 9th IFAC World Congress, Budapest) in the control of nonminimum-phase plants. Since it is not restricted to controlling the plant at the assumed I/O transport delay, it is also suitable for plants with unknown or time-varying dead times. The CAMAC algorithm has been successfully implemented in the control of mean arterial pressure in anesthetized animals.