Modeling and Control of Parametric Resonance in Ships

Abstract

This report considers two different approaches to control the roll motion of ships which experience parametric roll resonance. An Extremum Seeking feedback controller is designed which iteratively determines the optimal working point of the ship to avoid parametric resonance. This approach is indirect, since the ship heading and the ship speed are changed to violate the frequency condition for the onset of parametrically excited roll motion. A Model Predictive Controller is implemented for the purpose of minimizing the roll amplitude of the ship. Contrary to the approach with the Extremum Seeking control, the Model Predictive Controller influences the roll subsystem directly by computing the optimal control torque to stabilize the roll motion.