Reduced-order observer design for one-sided lipschitz nonlinear systems with unknown inputs

This paper presents a novel reduced-order observer based controller for a class of Lipschitz nonlinear systems, described by a set of second order ordinary differential equations. The control law is designed based on the measured output and estimated states. The main features are: (1) The computation cost is reduced noticeably, since the observer is a reduced-order one; (2) The controller guarantees semi-global exponential stability for both estimation and tracking error; and (3) The proposed method can be used in a large range of applications, especially in mechanical systems. The effectiveness of the proposed method is investigated through the numerical simulation for a two-degrees-of-freedom robot manipulator acting on a horizontal worktable.

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Full-Order and Reduced-order Observer Design for a Class of Fractional-order Nonlinear Systems

Asian Journal of Control ◽

10.1002/asjc.1230 ◽

2016 ◽

Vol 18 (4) ◽

pp. 1467-1477 ◽

Cited By ~ 15

Author(s):

Yong-Hong Lan ◽

Liang-Liang Wang ◽

Lei Ding ◽

Yong Zhou

Keyword(s):

Nonlinear Systems ◽

Fractional Order ◽

Observer Design ◽

Reduced Order ◽

Reduced Order Observer

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Reduced-order observer design for nonlinear systems

2007 European Control Conference (ECC) ◽

10.23919/ecc.2007.7069046 ◽

2007 ◽

Cited By ~ 6

Author(s):

Daniele Carnevale ◽

Dimitrios Karagiannis ◽

Alessandro Astolfi

Keyword(s):

Nonlinear Systems ◽

Observer Design ◽

Reduced Order ◽

Reduced Order Observer

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Full-Order and Reduced-Order Exponential Observers for Discrete-Time Nonlinear Systems With Incremental Quadratic Constraints

Journal of Dynamic Systems Measurement and Control ◽

10.1115/1.4041712 ◽

2018 ◽

Vol 141 (4) ◽

Cited By ~ 3

Author(s):

Wei Zhang ◽

Younan Zhao ◽

Masoud Abbaszadeh ◽

Mingming Ji

Keyword(s):

Nonlinear Systems ◽

Discrete Time ◽

Exponential Convergence ◽

Estimation Error ◽

Observer Design ◽

Linear Matrix ◽

Discrete Time System ◽

Quadratic Constraints ◽

Reduced Order ◽

Reduced Order Observer

This paper considers the observer design problem for a class of discrete-time system whose nonlinear time-varying terms satisfy incremental quadratic constraints. We first construct a circle criterion based full-order observer by injecting output estimation error into the observer nonlinear terms. We also construct a reduced-order observer to estimate the unmeasured system state. The proposed observers guarantee exponential convergence of the state estimation error to zero. The design of the proposed observers is reduced to solving a set of linear matrix inequalities. It is proved that the conditions under which a full-order observer exists also guarantee the existence of a reduced-order observer. Compared to some previous results in the literature, this work considers a larger class of nonlinearities and unifies some related observer designs for discrete-time nonlinear systems. Finally, a numerical example is included to illustrate the effectiveness of the proposed design.

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