Adaptive fuzzy control for SWATH ship seakeeping characteristics

This paper sets out to explore the seakeeping problems of SWATH ships which may have a tendency of instability. An adaptive fuzzy controller is designed to ensure the stability of SWATH pitch motion, and also to reduce the heave motion. When the ship sails in a sea way the coefficients are changing for different heave displacement etc. The controller also anticipates the action of dynamic hydrodynamic working on the ship performance. The adjustable parameters in the used control system are updated using a fuzzy descent adaptation algorithm. Simulation tests show the method´s efficiency.