Fuzzy Adaptive Output Tracking Control for a Class of Uncertain Nonlinear Systems
Author(s): Tian Wei-gang, Wang Yin-he, Li Yu-jiao
Pages: 91-97
Year: 2015 Issue: 1
Journal: Journal of Guangdong University of Technology
Keyword: fuzzy logic system; time-varying parameter; output tracking; adaptive control;
Abstract: In this paper, a fuzzy adaptive output tracking controller is designed for a class of uncertain nonlinear systems to track a given sign.First, a time-varying parameter is introduced into the Gaussian membership functions of the rule antecedent, so that a new set of fuzzy rules with a time-varying parame-ter is given.This implies that the update motion of time-varying parameter changes not only the centers and widths of Gaussian membership functions, but also the output of the previous Mamdani fuzzy logic system, and thus a new fuzzy logic system with a time-varying parameter is synthesized.And then the modified fuzzy logic system can be used to approximate the unknown nonlinear term of the system, and the adaptive laws of time-varying parameter and the estimated values of the fuzzy approximate accuracy can be constructed, accordingly the fuzzy adaptive output tracking controller of the system can be synthe-sized.The advantage of the proposed method in this paper is that by the full use of existing limited num-ber of fuzzy rules, the fuzzy adaptive output tracking controller can be synthesized with more fewer adap-tive laws.Finally, the Duffing system′s simulation example demonstrates that the proposed method in this paper is feasible and effective.
Pages: 91-97
Year: 2015 Issue: 1
Journal: Journal of Guangdong University of Technology
Keyword: fuzzy logic system; time-varying parameter; output tracking; adaptive control;
Abstract: In this paper, a fuzzy adaptive output tracking controller is designed for a class of uncertain nonlinear systems to track a given sign.First, a time-varying parameter is introduced into the Gaussian membership functions of the rule antecedent, so that a new set of fuzzy rules with a time-varying parame-ter is given.This implies that the update motion of time-varying parameter changes not only the centers and widths of Gaussian membership functions, but also the output of the previous Mamdani fuzzy logic system, and thus a new fuzzy logic system with a time-varying parameter is synthesized.And then the modified fuzzy logic system can be used to approximate the unknown nonlinear term of the system, and the adaptive laws of time-varying parameter and the estimated values of the fuzzy approximate accuracy can be constructed, accordingly the fuzzy adaptive output tracking controller of the system can be synthe-sized.The advantage of the proposed method in this paper is that by the full use of existing limited num-ber of fuzzy rules, the fuzzy adaptive output tracking controller can be synthesized with more fewer adap-tive laws.Finally, the Duffing system′s simulation example demonstrates that the proposed method in this paper is feasible and effective.
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