A separation principle for dynamic positioning of ships: theoretical and experimental results

Author

Loria, Antonio ; Fossen, Thor I. ; Panteley, Elena

Author_Institution

CNRS, St. Martin d´´Heres, France

Volume

8

Issue

2

fYear

2000

fDate

3/1/2000 12:00:00 AM

Firstpage

332

Lastpage

343

Abstract

Presents a globally asymptotically stabilizing (GAS) controller for regulation and dynamic positioning of ships, using only position measurements. It is assumed that these are corrupted with white noise hence a passive observer which reconstructs the rest of the states is applied. The observer produces noise-free estimates of the position, the slowly varying environmental disturbances and the velocity which are used in a proportional-derivative (PD)-type control law. The stability proof is based on a separation principle which holds for the nonlinear ship model. This separation principle is theoretically supported by results on cascaded nonlinear systems and standard Lyapunov theory, and it is validated in practice by experimentation with a model ship scale 1:70

Keywords

Lyapunov methods; asymptotic stability; cascade systems; nonlinear control systems; observers; position control; position measurement; ships; two-term control; white noise; cascaded nonlinear systems; dynamic positioning; globally asymptotically stabilizing controller; noise-free estimates; nonlinear ship model; passive observer; proportional-derivative-type control law; separation principle; slowly varying environmental disturbances; stability proof; standard Lyapunov theory; Marine vehicles; Nonlinear systems; Observers; PD control; Position measurement; Proportional control; Stability; Velocity control; White noise; Working environment noise;

fLanguage

English

Journal_Title

Control Systems Technology, IEEE Transactions on

Publisher

ieee

ISSN

1063-6536

Type

jour

DOI

10.1109/87.826804

Filename

826804