Optimal Path Following Controller Design Based on Linear Quadratic Regulator for Underactuated Ships in Varying Wave and Wind Conditions

Abstract

This study presents an optimisation-based approach for determining controller gains in ship path-following under varying sea states, wave, and wind directions. The dynamic Line of Sight approach is used to regulate the rudder angle and guide the Esso Osaka ship along the desired path. Gains are optimised using a genetic algorithm and a comprehensive cost function. The analysis covers a range of wave attack directions and sea states to evaluate the controller performance. Results demonstrate effective convergence to the desired path, although a steady-state error persists. Heading and rudder angle performance analyses show successful convergence and dynamic adjustments of the rudder angle to compensate for deviations. The findings underscore the influence of wave and wind conditions on ship performance and highlight the need for precise gain tuning. This research contributes insights into optimising and evaluating path-following controllers for ship navigation.

Keywords

Ship manoeuvring / Optimal control / Wave and wind forces / Genetic algorithm / LQR control