Online estimation of ship steering dynamics and its applications in designing an optimal autopilot

A recursive least square (RLS) algorithm applied to a multivariate autoregressive (MAR) process is used to estimate ship steering dynamics online. The estimation method is then linked to the linear quadratic (LQ) algorithm to design an optimal autopilot for steering ships. The estimation method was applied to several ships and model ships and, in all cases, the estimated parameters converged well. The design algorithm was used to construct a tracking system for course keeping and course-changing manoeuvres. Simulation results for the ships show the robustness of the estimation method and prove that the autopilot has very good performance.