Comments on ``Nonlinear Output Feedback Control of Dynamically Positioned Ships Using Vectorial observer Backstepping''
(1998) In IEEE Trans. Control Systems Technology 6(3). p.439-441- Abstract
- The decomposition of nonlinear output feedback control into an observer and a state feedback control is an open problem. A solution for dynamic positioning of ships has been proposed in the above paper (1) and by Grovlen and Fossen, where an observer-based backstepping method is used. This note points out that the observer design in the above-mentioned papers does not cover unstable ship dynamics and suggests a remedy for an extended class of ships. The proof for the nonlinear observer used in the design in the above-mentioned papers only applies to ships with stable sway yaw dynamics. In the above-mentioned papers an example concerning thruster assisted mooring of a tanker is given, which does not fulfill the needed stability properties,... (More)
- The decomposition of nonlinear output feedback control into an observer and a state feedback control is an open problem. A solution for dynamic positioning of ships has been proposed in the above paper (1) and by Grovlen and Fossen, where an observer-based backstepping method is used. This note points out that the observer design in the above-mentioned papers does not cover unstable ship dynamics and suggests a remedy for an extended class of ships. The proof for the nonlinear observer used in the design in the above-mentioned papers only applies to ships with stable sway yaw dynamics. In the above-mentioned papers an example concerning thruster assisted mooring of a tanker is given, which does not fulfill the needed stability properties, so an extension to this case is highly motivated. We propose a method to extend the results, under a detectability condition. This condition implies stable surge dynamics, which is a natural assumption for ships. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/8497615
- author
- Robertsson, Anders LU and Johansson, Rolf LU
- organization
- publishing date
- 1998
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Marine systems, nonlinear systems, observer design, stability, state estimation.
- in
- IEEE Trans. Control Systems Technology
- volume
- 6
- issue
- 3
- pages
- 439 - 441
- external identifiers
-
- scopus:0032074820
- project
- RobotLab LTH
- Lund Research Programme in Autonomous Robotics, 1998-2001
- language
- English
- LU publication?
- yes
- id
- 2501e394-4a64-4961-8a0e-a83185807cbf (old id 8497615)
- date added to LUP
- 2016-04-04 13:33:40
- date last changed
- 2023-01-06 02:35:02
@article{2501e394-4a64-4961-8a0e-a83185807cbf, abstract = {{The decomposition of nonlinear output feedback control into an observer and a state feedback control is an open problem. A solution for dynamic positioning of ships has been proposed in the above paper (1) and by Grovlen and Fossen, where an observer-based backstepping method is used. This note points out that the observer design in the above-mentioned papers does not cover unstable ship dynamics and suggests a remedy for an extended class of ships. The proof for the nonlinear observer used in the design in the above-mentioned papers only applies to ships with stable sway yaw dynamics. In the above-mentioned papers an example concerning thruster assisted mooring of a tanker is given, which does not fulfill the needed stability properties, so an extension to this case is highly motivated. We propose a method to extend the results, under a detectability condition. This condition implies stable surge dynamics, which is a natural assumption for ships.}}, author = {{Robertsson, Anders and Johansson, Rolf}}, keywords = {{Marine systems; nonlinear systems; observer design; stability; state estimation.}}, language = {{eng}}, number = {{3}}, pages = {{439--441}}, series = {{IEEE Trans. Control Systems Technology}}, title = {{Comments on ``Nonlinear Output Feedback Control of Dynamically Positioned Ships Using Vectorial observer Backstepping''}}, volume = {{6}}, year = {{1998}}, }