Froude-Krylov force estimation and waypoint tracking control of an underactuated model boat

The current investigation combines the control of boat heading and speed into one logic framework using a proportional waypoint-following regulator in a surge-sway-yaw planer model based on a 1x0.55 m model boat. The proposed control logic uses the thrust angle and the thrust force as control inputs and the boat yaw angle and speed as control outputs. This control scheme is believed to be more intuitive in interpreting the human-machine interaction, and simpler in computational effort in both simulation and deployment. Three sets of hydrodynamic damping coefficients are extracted from the computational fluid dynamics (CFD) simulations assuming only the Froude-Krylov (FK) force and moment due to the incident wave without any structure obstruction. The study clarified the full hydrodynamic forces and moments required for a comprehensive simulation of fluid-structure interaction. The FK simulation results establish the benchmark that can be used to compare and demonstrate effects of different levels of hydrodynamic simplification on path following performances.