Synthesis of controllers for arbitrary pole placement in discrete plants including unstable zeros with extensions to adaptive control

doi:10.1016/S0016-0032(96)00130-5

Journal of the Franklin Institute

Volume 335, Issue 3, April 1998, Pages 471-502

https://doi.org/10.1016/S0016-0032(96)00130-5 Get rights and content

Abstract

This paper presents new simultaneous pole and zero placement schemes based on the use of feedforward and feedback compensators. The main novelty is that the plant is allowed to possess unstable zeros which are not required to be included as zeros of the reference model. The control objective of model-following is achieved by including a feedforward compensator between either the reference or the control signals and the plant output which is incorporated to the usual schemes consisting in a precompensator and a feedback compensator. Basically, two control schemes are presented, but some extensions are given allowing signal feedforward injections at intermediate state variables of the plant instead of the standard injections at the output and the use of blocking filters for the significant frequencies of the output of the feedforward compensator. These schemes lead to two diophantine equations, one being used for standard pole placement while the other being basically used for the placement of zeros in prescribed positions. Several numerical simulations are given to illustrate the capability of the schemes for simultaneous pole and zero placement in the absence and in the presence of noise and their application for adaptive control.

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Citation Excerpt :
Generally speaking, pole-placement type adaptive schemes are applicable even when the plant is not inversely stable. However, the control objectives inspired in arbitrary model-following schemes cannot be exactly achieved for inversely unstable plants due to the need for cancellation of the unstable plant zeros (see, for instance [8]). The technique used in [13], and references therein, to avoid singularities has been the estimates modification so that the modified estimated plant model remains controllable for all time and at the limit.
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ArticleSynthesis of controllers for arbitrary pole placement in discrete plants including unstable zeros with extensions to adaptive control

Abstract

Automatica

Computer Controlled Systems

Self-tuning control of nonminimum-phase systems

Automatica

New design method for model reference adaptive control for nonminimum phase discrete-time systems with disturbances

Model reference adaptive control algorithm capable of arbitrary zeros placement

Int. J. of Systems Sci.

Frequency-domain and design of feedback systems for specified insensitivity of time-domain to parameter uncertainty

Int. J. of Control

Frequency domain synthesis of a class of multivariable control systems

Automation and Remote Control

Article
Synthesis of controllers for arbitrary pole placement in discrete plants including unstable zeros with extensions to adaptive control