WSU researchers have developed a guidance system that yields a faster convergence rate of the ship to its desired trajectory than existing systems. The new algorithm varies the radius in the guidance algorithm exponentially as opposed to linear variations in existing schemes. This was done to prevent the system from over-reacting for small cross track errors and to force the ship to operate under steeper desired heading angle than the one specified by existing systems. As a consequence, ships using the new guidance system will converge faster to their desired trajectories than those implementing existing systems.
Moreover, existing systems do not have any provision in their design to correct for the drift of the ship from its desired trajectory that is induced by environmental resistance or persistent disturbances. The new guidance algorithm has the capability of detecting drift and correcting for it.
The use of the new guidance algorithm with a robust controller will allow autonomous operation of the ship that will be robust to modeling uncertainties and external disturbances.
Commercial Applications:
• Ocean vessel systems
Competitive Advantages:
• Autonomous operation of ships
• Exponential radius variation
• Drift control of ships
Publications:
Klahed,N. and Chalhoub, N.G., 2010, “Guidance and Control Scheme for Under-actuated marine Surface Vessels,” Proceeding of the 2010 American Control Conference (ACC2010), Baltimore, Maryland, USA, June 30-July2.
Khaled,N. and Chalhoub,N.G., 2010, “Self Tuning Fuzzy Sliding Controller for the Ship Heading Problem,” Dynamic Systems and Control Conference (DSCC 2010), Cambridge, Massachusetts. USA, September 13-15.
Moreira, L., Fosse, T.I. and Guedes Soares, C., 2007, “Path Following Control System for a Tanker Ship Model,” Ocean Engineering OE-34:2074-2085
Fossen, T.I., Breivik, M. and Skjetne, R, 2003, “Line-Of-Sight Path Following of Underactuated Marine Craft,” Proceeding of the Sixth IFAC Conference on maneuvering and Control of Marine Crafts (MCMC’2003), Girona, Spain, 244-249
Breivik, M., 2003, Nonlinear maneuvering Control of Underactuated Ships, Master Thesis, Norwegian university of Science and Technology, Trondheim, Norway.