An Adaptive Position Keeping Algorithm For Autonomous Sailboats Autonomous sailboats are potential solutions for insitu ocean measurement thanks to their high energy efficiency. Indeed, the ability for them to maintain their position is crucial for ocean data collection. Previous study has demonstrated a position keeping method for an autonomous sailboat and has theoretically proved the stability. As this method is ineffective against wind disturbance, we propose a more feasible algorithm for real environment in this paper. A retrofitted model sailboat is developed to evaluate the performance of our approach in an artificial wind field. Simulation and experiment results under several different cases show that our proposed algorithm is robust.

A New TurbineSail Coupled Propulsive System for Autonomous Sailboats * Autonomous sailboats are good candidates to perform longterm missions in oceans since they are windpropelled. Furthermore, wind turbine is a useful device that can provide autonomous sailboats with necessary electrical energy to support controller, drive rudder and sail. Some current applications for onboard wind turbines can reduce fuel demand of autonomous power sailboats. Apart from necessary electrical energy supply, autonomous sailboats also need enough propelling forces to move efficiently in the direction of the course.In this paper, we propose a new turbinesail coupled system that utilizes wind sources by adding two vertical wind turbines on both sides of the sail. Experiments are conducted in a wind tunnel. The results show that the system can increase the maximum propelling force when sailing downwind and allow further regulation of the force by slowing the rotation speed of wind turbine on one side.