# Design, Modeling, and Simulation of a Wing Sail Land Yacht
## 1 Introduction
[25] design and simulate a simple, reliable and highly autonomous sailboat. They choose a symmetrical, free-rotating wing sail with an additional tail for actuating the wing and controlling its angle of attack. The design was further investigated with a computation flow dynamics simulation software. 3. [PERSON] et al. [26] design and simulate small (1 m) semi-autonomous robotic sailboat platform variants equipped with a symmetric airfoil sail, a thin, bulbed keel, \begin{table}
\begin{tabular}{l c c c c c c c c c} \hline \hline \multirow{2}{*}{**Source**} & \multicolumn{5}{c}{**Wing Sail**} & \multicolumn{5}{c}{**Chassis**} \\ \cline{2-10}  & **Airfoil** & **Free Rot.** & **Angle Range** & **Wingspan** & **Lat. Area** & **Mass** & **Material** & **Wheels** & **Mass** \\  & & & **(°)** & **(m)** & **(m\({}^{2}\))** & **(kg)** & & & **(kg)** \\ \hline [PERSON] et al. [11] & NACA0018 & No & 0 to 360 & 1 & 0.25 & 2.15 & Aluminum & 4 & 19 \\ [PERSON] et al. [15] & 3 \(\times\) NACA0018 & No & 0 to 360 & \(3\times 1\) & \(3\times 0.25\) & \(3\times 2.15\) & Aluminum & 4 & 19 \\ [PERSON] et al. [13] & NACA0015 & Yes & 0 to 360 & 2.5 & 1.25 & - & Steel & 4 & - \\ [PERSON] et al. [16] & NACA0012 & No & - & 1 & 0.5 & - & - & 3 & 8 \\ [PERSON] et al. [17] & NACA0015 & No & 0 to 270 & 0.8 & 0.24 & - & Steel \& Plastic & 4 & - \\ [PERSON] et al. [18] & NACA0012 & No & - & 3 & 0.66 & - & - & 3 & 100 \\ [PERSON] et al. [10] & NACA0015 & No & - & 5.44 & 12 & 49 & - & 3 & 35 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Reviewed autonomous land yachts. and a tail-vane rudder, replacing the traditional water rudder. They adopt MATLAB to perform 2D and 3D dynamic simulations of the tail-vane rudder design. 4. [PERSON] et al. [27] design and simulate an autonomous sailboat dynamic model with four degrees of freedom. The simulations were carried out with MATLAB/Simulink to determine the effect of flap and rudder deflection angles on boat dynamics. This survey on the simulation of platforms propelled by wing sails shows that none utilizes the Robotic Operating System (ROS) middleware and the Gazebo simulator. The work presented in this article offers a novel simulated environment for autonomous land yachts using the ROS middleware and the Gazebo simulator. Furthermore, two Gazebo plugins are developed to (i) act as a wind sensor and (ii) to set the flap angular position. This article is a condensed version of the thesis presented in Reference [28] and contributes to robotic sailing through the design, modeling, and simulation of an autonomous rigid wing sail land yacht, which can be used to survey and monitor the shoreline (more specifically sandy areas), with the help of the Gazebo (Gazebo simulator website: [[http://gazebosim.org](http://gazebosim.org)]([http://gazebosim.org](http://gazebosim.org)), accessed on 19 March 2021) simulator and the Robot Operating System (ROS) (ROS website: [[https://www.ros.org](https://www.ros.org)]([https://www.ros.org](https://www.ros.org)), accessed on 19 March 2021) middleware. Moreover, the proposed method can be followed to perform a priori evaluation of alternative wing configurations and control algorithms, i.e., without the need to build the actual land yachts. The proposed method constitutes a novel approach to the design and simulation of free rotating wing sail autonomous land yachts. This kind of sail, which is is controlled trough the tail flap, minimizes the energy consumed by the sail control system. Once actuated, the flap generates a linear force that induces torque on the wing sail. This shifts slightly the wing sail from the wind direction, defining the sail's angle of attack.