Optimal Altitude Determination for a Flying Drone in an Underground Mine Environment

The nature of the task performed by quadrotors in underground mining operations places them in proximity to other objects and surfaces, generating external forces and torques due to aerodynamic effects. Flying a quadrotor at a lower altitude in an underground mining operation risks its efficiency being affected by ground effects. Flying at a high altitude poses a threat of crashing into the ceiling due to ceiling effects. This study investigates these interactions by employing a single-motor dynamometer mounted on a stepper motor, simulating UAV movements in proximity to various obstacles within an underground mine. The experiments assess the impact of altitude, surface proximity, and ventilation airflow on aerodynamic performance. The results show that the influence of ground effects is not significant when the quadrotor's altitude from the ground is equivalent to 2.7 times the radii of the propeller blade used in its design when operating within the proximity of ground and wall effects.