Modeling and Implementation of Tacking for Wing Sail Land-Yacht.

Wing sail land-yacht is one of the promising vehicles which utilizes wind energy. However, its autonomous driving in all directions is challenging, especially the upwind steering (tacking) maneuver. This paper proposes a novel design of low cost three-wheeled land-yacht with a T-frame and a foamed wing sail, which is able to move and tack upwind owing to the lightweight design. To achieve the successful tacking, a model describing the steering process is developed based on the law of energy conservation and used to predict the minimum initial velocity for steering. In the model, an acceleration error function C induced by the environment disturbance and manufacturing error is identified by a series of experiments. Finally, the tacking experiments verify the steering model and show that the land-yacht can achieve the tacking with a high success rate of 94.7%, based on the predicted minimum initial steering velocity.