Dynamics and control of thrusters for ships and underwater vehicles

Dynamic effects were reported in the literature in recent literature but mathematical models of the axial flow phenomena only covered near-zero speed conditions. These models could not be used for conditions with current or for ships at voyage speed. A large signal model was developed. A nonlinar controller that provide improved control. The model and the new control concept explanined phenomena with overshoot in propeller speed controls observed during many years and proposed a more accurate control system. The results are important for accurate manoeuvring of autonomous underwater vehicles and robots.