# High-Fidelity Drone Simulation with Depth Camera Noise and Improved Air Drag Force Models
## 4 Conclusions and Discussion
### Discussion
\begin{table}
\begin{tabular}{p{42.7 pt} p{42.7 pt} p{42.7 pt} p{42.7 pt} p{42.7 pt} p{42.7 pt} p{42.7 pt} p{42.7 pt}} \hline \hline
**Simulation** & **Dynamics** & **Visual Quality** & **Sensor Type** & \begin{tabular}{c} **Sensor Noise** \\ **Model** \\ \end{tabular} & \begin{tabular}{c} **VR** \\ **Headset** \\ \end{tabular} & **Vehicles** & \begin{tabular}{c} **Aerodynamic** \\ **Drag Force Model** \\ \end{tabular} \\ \hline \multirow{2}{*}{Gazebo [47]} & \multirow{2}{*}{Gazebo-based} & \multirow{2}{*}{Low(OpenGL)} & \multirow{2}{*}{IMU, GPS, RGBD, Lidar} & \multirow{2}{*}{X} & \multirow{2}{*}{X} & \multirow{2}{*}{X} & \multirow{2}{*}{Single} & \begin{tabular}{c} Velocity (drone), \\ rotation dependent \\ coefficients (drone) \\ \end{tabular} \\ \hline \multirow{2}{*}{Hector [20; 48]} & \multirow{2}{*}{Gazebo-based} & \multirow{2}{*}{Low (OpenGL)} & \multirow{2}{*}{IMU, GPS, RGBD, Lidar} & GPS, IMU & X & Single & \begin{tabular}{c} Velocity (drone), \\ angular velocities \\ (rotors) \\ \end{tabular} \\ \hline \multirow{2}{*}{RotorS [49]} & \multirow{2}{*}{Gazebo-based} & \multirow{2}{*}{Low (OpenGL)} & \multirow{2}{*}{IMU, GPS, RGBD, Lidar} & \multirow{2}{*}{X} & \multirow{2}{*}{X} & \multirow{2}{*}{Single} & \begin{tabular}{c} Velocity (drone), \\ angular velocities \\ (rotors) \\ \end{tabular} \\ \hline \multirow{2}{*}{FlightGoggles [50]} & \multirow{2}{*}{Flexible} & \multirow{2}{*}{High (Unity)} & \multirow{2}{*}{IMU, GPS, RGB} & \multirow{2}{*}{IMU, RGB} & \multirow{2}{*}{O} & \multirow{2}{*}{Single} & \begin{tabular}{c} Velocity (drone), \\ rotation (drone) \\ \end{tabular} \\ \hline \multirow{2}{*}{Airsim [26]} & \multirow{2}{*}{PhysX} & \multirow{2}{*}{\begin{tabular}{c} High (Unreal Engine) \\ \end{tabular} } & \multirow{2}{*}{IMU, GPS, RGBD, Lidar} & \multirow{2}{*}{O} & \multirow{2}{*}{Multiple} & \begin{tabular}{c} Velocity (drone), \\ rotation (drone) \\ \end{tabular} \\ \hline \multirow{2}{*}{Airsim with our model} & \multirow{2}{*}{PhysX} & \multirow{2}{*}{\
\begin{tabular}{c} High (Unreal Engine) \\ \end{tabular} } & \multirow{2}{*}{IMU, GPS, RGBD, Lidar} & \multirow{2}{*}{O} & \multirow{2}{*}{Multiple} &
\begin{tabular}{c} Velocity (drone), \\ rotation (drone), \\ thrust values \\ (rotors) \\ \end{tabular} \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Comparison of drone simulators. by sunlight [24]. In our current rotor drag force model experiments, we focused on low wind speeds below 4 m/s, where the wind's impact on the drone's position is negligible [46]. However, for wind speeds exceeding 4 m/s, wind can affect the rotor drag force, potentially leading to errors in the model. As part of our future work, we plan to investigate the influence of wind speed on the rotor drag force model. Furthermore, while the Intel Realsense D435 depth camera is widely used in autonomous drones, we aim to test other depth cameras to offer a broader range of camera options for the drone simulator. Our future work will also explore more realistic effects related to drone operations and delve into the impact of thrust differences on the model during complex trajectories. It is important to note that the PWM-to-ESC and rotor thrust relationship can vary depending on the specific propeller. To provide more propeller options within the drone simulator, we intend to conduct experiments to obtain PWM-thrust relationships for different propellers. Conceptualization, W.K. and H.M.; methodology, W.K., T.L. and H.M.; data curation, W.K., T.L, Y.H., M.D. and J.F.M.Y. ; writing--original draft preparation, W.K. and T.L. ; writing--review and editing, W.K. and T.L. ; visualization, W.K., Y.H. and T.L. ; supervision, H.M. All authors have read and agreed to the published version of the manuscript. This research was supported by the MSIT(Ministry of Science and ICT), Korea, under the ITRC(Information Technology Research Center) support program (IITP-2023-2020-0-01460) supervised by the IITP(Institute of Information & Communications Technology Planning & Evaluation. Not applicable. The authors declare no conflict of interest.