{"id":{"repo_id":"nus","oai_identifier":"oai:scholarbank.nus.edu.sg:10635/13901"},"canonical_url":"https://search.dev.ndltd.org/etd/nus/oai:scholarbank.nus.edu.sg:10635/13901","repository":{"repo_id":"nus","name":"National University of Singapore","base_url":"https://scholarbank.nus.edu.sg/oai/request"},"display":{"title":"Robust adaptive control of uncertain nonlinear systems","abstract":"In this thesis, robust adaptive control is investigated for uncertain nonlinear systems. The main purpose of the thesis is to develop adaptive control strategies for several classes of general nonlinear systems in strict-feedback form with different uncertainties including unknown parameters, unknown nonlinear systems functions, unknown disturbances, and unknown time delays. Systematic controller designs are presented using backstepping methodology, neural network parametrization and robust adaptive control. The results are derived based on rigorous Lyapunov stability analysis. The control performance of the closed-loop systems is explicitly analyzed. Decoupled backstepping is utilized for practical controller design, which aims at seeking the boundedness of the states rather than the asymptotical stability. For nonlinear systems with unknown time delays, Lyapunov-Krasovskii functionals are used in the Lyapunov function candidates such that the uncertainties from unknown time delays are compensated for and the design of the stabilizing control law is free from unknown time delays. Universal controller design is presented for systems without knowledge of the signs of high-frequency gain using Nussbaum functions.","abstract_html":"In this thesis, robust adaptive control is investigated for uncertain nonlinear systems. The main purpose of the thesis is to develop adaptive control strategies for several classes of general nonlinear systems in strict-feedback form with different uncertainties including unknown parameters, unknown nonlinear systems functions, unknown disturbances, and unknown time delays. Systematic controller designs are presented using backstepping methodology, neural network parametrization and robust adaptive control. The results are derived based on rigorous Lyapunov stability analysis. The control performance of the closed-loop systems is explicitly analyzed. Decoupled backstepping is utilized for practical controller design, which aims at seeking the boundedness of the states rather than the asymptotical stability. For nonlinear systems with unknown time delays, Lyapunov-Krasovskii functionals are used in the Lyapunov function candidates such that the uncertainties from unknown time delays are compensated for and the design of the stabilizing control law is free from unknown time delays. Universal controller design is presented for systems without knowledge of the signs of high-frequency gain using Nussbaum functions.","abstract_has_math":false,"creators":["HONG FAN"],"institution":null,"degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2004,"date_issued":"2004-04-05","date_published":"2004-04-05","updated_at":"2026-07-24T03:30:34Z","subjects":["nonlinear systems, time-delay systems, backstepping, neural networks, Nussbaum functions, adaptive control"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":null,"outbound_label":null,"outbound_source":null},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:creator","label":"Author","values":["HONG FAN"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.issued","label":"Date","values":["2004-04-05"]},{"key":"dc:relation.isreferencedby","label":"Dc Relation Isreferencedby","values":["http://scholarbank.nus.edu.sg/handle/10635/13901"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["nonlinear systems, time-delay systems, backstepping, neural networks, Nussbaum functions, adaptive control"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://scholarbank.nus.edu.sg/bitstreams/fbe3bf90-23ea-44ac-9ee5-22c5c3beb22f/download"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["In this thesis, robust adaptive control is investigated for uncertain nonlinear systems. 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For nonlinear systems with unknown time delays, Lyapunov-Krasovskii functionals are used in the Lyapunov function candidates such that the uncertainties from unknown time delays are compensated for and the design of the stabilizing control law is free from unknown time delays. Universal controller design is presented for systems without knowledge of the signs of high-frequency gain using Nussbaum functions."]},{"key":"dc:format.checksum.md5","label":"Dc Format Checksum Md5","values":["686f31710db1c613014aebda3d2a11ea","1eb269b4b9701590f89334caa98e3a35"]},{"key":"dc:title","label":"Title","values":["Robust adaptive control of uncertain nonlinear systems"]}]}],"canonical_facts":{"dc:creator":["HONG FAN"],"dc:date.issued":["2004-04-05"],"dc:description.abstract":["In this thesis, robust adaptive control is investigated for uncertain nonlinear systems. 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For nonlinear systems with unknown time delays, Lyapunov-Krasovskii functionals are used in the Lyapunov function candidates such that the uncertainties from unknown time delays are compensated for and the design of the stabilizing control law is free from unknown time delays. Universal controller design is presented for systems without knowledge of the signs of high-frequency gain using Nussbaum functions."],"dc:format.checksum.md5":["686f31710db1c613014aebda3d2a11ea","1eb269b4b9701590f89334caa98e3a35"],"dc:identifier.uri":["https://scholarbank.nus.edu.sg/bitstreams/fbe3bf90-23ea-44ac-9ee5-22c5c3beb22f/download"],"dc:relation.isreferencedby":["http://scholarbank.nus.edu.sg/handle/10635/13901"],"dc:subject":["nonlinear systems, time-delay systems, backstepping, neural networks, Nussbaum functions, adaptive control"],"dc:title":["Robust adaptive control of uncertain nonlinear systems"],"dc:type":["Thesis"]},"updated_at":"2026-07-24T03:30:34Z"}