抄録
Understanding gas concentration distributions near the ground is important for disaster prevention and safety management. In this study, as part of expanding drone applications, we tried to develop the CO₂ gas sensing method using formation flight with four drones. By flow simulation, we confirmed the gas updraft flow not only velocity but also concentration distribution generated by the drones. It was confirmed that the updraft flow velocity around the sensor was 2 m/s at the height of 0.3 m, and the concentration ratio was between 0.95 and 0.99, respectively. Then, to stable the formation flight with four drones, a rope was used between the connecting rod and the drone. Then, the CO₂ sensing experiment using this approach was conducted. The average concentration values of 4,290 and 4,710 ppm of three experiments were measured at the heights of 0.5 m and 0.3 m, respectively. Moreover, we tried to predict the concentration at the CO₂ source using the steady-state one-dimensional convection-diffusion equation. It was found that the predicted concentration of 4,772 ppm at the CO₂ source was in between 4,700 and 4,800 ppm measured by sensor. Finally, the effectiveness of prediction was confirmed.
