Parameter estimation and compensation in systems with nonlinearly parameterized perturbations

作     者：Grip, Havard Fjaer Johansen, Tor A. Imsland, Lars Kaasa, Glenn-Ole 

作者机构：NTNU Dept Engn Cybernet NO-7491 Trondheim Norway Cybernet AS NO-7038 Trondheim Norway StatoilHydro Res Ctr NO-3908 Porsgrunn Norway 

出 版 物：《AUTOMATICA》 (自动学)

年 卷 期：2010年第46卷第1期

页      面：19-28页

核心收录：

学科分类：0711[理学-系统科学] 0808[工学-电气工程] 07[理学] 08[工学] 070105[理学-运筹学与控制论] 081101[工学-控制理论与控制工程] 0811[工学-控制科学与工程] 0701[理学-数学] 071101[理学-系统理论] 

基　　金：Research Council of Norway 

主　　题：Nonlinear system control Uncertain nonlinear systems Adaptive control Nonlinear observer design 

摘      要：We consider a class of systems influenced by perturbations that are nonlinearly parameterized by unknown constant parameters, and develop a method for estimating the unknown parameters. The method applies to systems where the states are available for measurement, and perturbations with the property that an exponentially stable estimate of the unknown parameters can be obtained if the whole perturbation is known. The main contribution is to introduce a conceptually simple, modular design that gives freedom to the designer in accomplishing the main task, which is to construct an update law to asymptotically invert a nonlinear equation. Compensation for the perturbations in the system equations is considered for a class of systems with uniformly globally bounded solutions, for which the origin is uniformly globally asymptotically stable when no perturbations are present. We also consider the case when the parameters can only be estimated when the controlled state is bounded away from the origin, and show that we may still be able to achieve convergence of the controlled state. We illustrate the method through examples, and apply it to the problem of downhole pressure estimation during oil well drilling. (C) 2009 Elsevier Ltd. All rights reserved.