Design and analysis of an autonomous controlled four wheeled land yacht

Land yacht is a new type of mobile robot powered by the wind through the use of a sail. The structure and analysis of an autonomous controlled four wheeled land yacht are presented in this paper. The land yacht consists of a hull, a studding sail, a dual-front-wheel steering mechanism, two rear wheels, an axle, two wire ropes, a servomotor and a steering engine. As the studding sail and the dual-front-wheel steering mechanism are maneuvered by the servomotor and steering engine with a gyroscope and an aerovane, respectively, the land yacht reaches the destination by itself. Relationships between maximum true speed, start-up wind speed and angle of attack are established based on the aerodynamic characteristics of the NACA0018 airfoil. Requirements are found for the land yacht to maintain stability and to not tip over. Stability and start-up wind speed are discussed for different true wind angles and angles of attack. Finally, the prototype is presented and experiments of stability and start-up wind speed are introduced to validate these requirements. The results show that the maximum true wind speed blowing the land yacht can be 16.2 m/s and the minimum start-up wind speed is just 3.9 m/s.