DocumentCode :
2696449
Title :
Modeling the influence of non-minimum phase zeros on gradient based linear iterative learning control
Author :
Owens, David H. ; Chu, Bing ; Cai, Zhonglun ; Rogers, Eric ; Freeman, Chris T. ; Lewin, Paul L.
Author_Institution :
Dept. of Autom. Control & Syst. Eng., Univ. of Sheffield, Sheffield, UK
fYear :
2010
fDate :
8-10 Sept. 2010
Firstpage :
392
Lastpage :
397
Abstract :
The subject of this paper is modeling of the influence of non-minimum phase plant dynamics on the performance possible from gradient based norm optimal iterative learning control algorithms. It is established that performance in the presence of right-half plane plant zeros typically has two phases. These consist of an initial fast monotonic reduction of the L2 error norm followed by a very slow asymptotic convergence. Although the norm of the tracking error does eventually converge to zero, the practical implications over finite trials is apparent convergence to a non-zero error. The source of this slow convergence is identified and a model of this behavior as a (set of) linear constraint(s) is developed. This is shown to provide a good prediction of the magnitude of error norm where slow convergence begins. Formulae for this norm are obtained for single-input single-output systems with several right half plane zeroes using Lagrangian techniques and experimental results are given that confirm the practical validity of the analysis.
Keywords :
gradient methods; learning systems; optimal control; L2 error norm; Lagrangian techniques; gradient based norm optimal iterative learning control algorithm; monotonic reduction; nonminimum phase plant dynamics; nonminimum phase zero; right half plane zero; single-input single-output systems; Algorithm design and analysis; Approximation methods; Convergence; Cost function; Hilbert space; Mathematical model; Predictive models;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Control Applications (CCA), 2010 IEEE International Conference on
Conference_Location :
Yokohama
Print_ISBN :
978-1-4244-5362-7
Electronic_ISBN :
978-1-4244-5363-4
Type :
conf
DOI :
10.1109/CCA.2010.5611338
Filename :
5611338
Link To Document :
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