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Output feedback stabilizability and passivity in nonstationary and nonlinear systems
Author(s) -
Barkana Itzhak
Publication year - 2010
Publication title -
international journal of adaptive control and signal processing
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.73
H-Index - 66
eISSN - 1099-1115
pISSN - 0890-6327
DOI - 10.1002/acs.1149
Subject(s) - passivity , control theory (sociology) , nonlinear system , lti system theory , invariant (physics) , transfer function , stability (learning theory) , constant (computer programming) , adaptive control , output feedback , computer science , nonlinear control , linear system , control (management) , mathematics , engineering , artificial intelligence , mathematical analysis , physics , quantum mechanics , machine learning , electrical engineering , mathematical physics , programming language
Passivity properties and passivity conditions have been shown to be very important for the stability of various methodologies of control with uncertainty in linear‐time‐invariant (LTI) systems. Many publications have defined the conditions that allow LTI systems to become strictly passive (and their transfer function strictly positive real) via constant or dynamic output feedback. As beyond the usual uncertainty, real‐world systems are not necessarily invariant, this paper expands the applicability of previous results to nonstationary and nonlinear systems. The paper first reviews a few pole–zero dynamics definitions in nonstationary systems and relates them to stability and passivity of the systems. The paper then finds the sufficient conditions that allow nonstationary systems to become stable and strictly passive via static or dynamic output feedback. Applications in robotics and adaptive control are also presented. Copyright © 2009 John Wiley & Sons, Ltd.