Optimization of Surface Ship Steering in Sea State.
Abstract
Propulsion losses are increased by added drag due to steering of the ship. A carefully designed automatic steering control provides the desired heading while it simultaneously minimizes the rudder activity and holds the potentials for reducing propulsive losses. A computer model of the SL-7 containership along with a cascaded controller (one pole, One zero) were coupled to a function minimization subroutine and a sea state generator program. This scheme provided the appropriate controller parameters in order to accomplish the best performance. The model was tested in calm waters and sea states (regular and irregular as well, for a certain speed and different encounter wave angles and encounter frequencies. Also, an adaptive control was studied which updates the controller parameters while either the environmental conditions or the ship's steering characteristics change in order to maintain optimal steering performance. Keywords: Computer models of the ship, Nomoto model, Regular seas, Optimized controller, Irregular seas, Minimization subroutine, and Adaptive control.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1984
- Accession Number
- ADA153616
Entities
People
- E. Horianopoulos
Organizations
- Naval Postgraduate School