High performance path following for marine vehicles using azimuthing podded propulsion

Podded propulsion systems offer greater maneuvering possibilities for marine vehicles than conventional shaft and rudder systems. As the propulsion unit rotates about its vertical axis to a specified azimuth angle, the entire thrust of the propeller contributes to the steering moment without relying on lift generation by a control surface such as a rudder. However, the larger sideforce and moment cause the ship to enter the nonlinear realm sooner than a ruddered vessel. Furthermore if the rudder or azimuthing propulsor is aft of the vessel's center of gravity then the system is non-minimum phase; during a turn the ship center initially moves in the direction opposite the turn. For these reasons it is necessary to design a robust maneuvering control system to set the azimuth angle of the propulsor in an intelligent and stable manner. This thesis focuses on the path following performance of a vessel with podded propulsion. The enhanced maneuvering abilities of such vessels allow the time constant of cross-track error response to be greatly reduced. Additionally these vessels can follow course changes and waypoints more precisely than ruddered vessels.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Mechanical Engineering.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2006

Author dc:creator

• Greytak, Matthew B. (Matthew Bardeen)

Advisor dc:contributor.advisor

• Michael S. Triantafyllou.

• Mechanical Engineering.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/35673

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/35673