Experimental Characterization of a Quadrotor’s Response to an Air Vortex Cannon

Unmanned aerial vehicles (UAVs) play an important role in civilian and military operations. They are being used in a wide array of applications, from military reconnaissance to commercial deliveries. UAVs are particularly useful in hostile environments, as they are able to remove the operator from potentially dangerous situations. A threat to UAVs in such environments is their vulnerability to shockwaves and blasts. Directed energy systems are a proven method of destabilizing UAVs due to shockwaves. UAVs are highly sensitive to both impulsive pressure disturbances and mechanical vibrations, which affect sensors and overall stability. This paper investigates the response of a micro-quadrotor, the Crazyflie 2.1, exposed to a sudden aerodynamic force generated by a directed blast from a vortex cannon while in hovering flight. The vortex blasts were generated from varying distances to adjust the intensities experienced by the quadrotor. In addition, the relative impact angle of the vortex ring to the drone was varied. Onboard inertial measurement unit (IMU) data was recorded during each quadrotor vortex interaction. The sensors analyzed included 3-axis gyroscope, 3-axis accelerometer, and barometer (temperature and pressure), as well as the drones estimated pitch, roll, and yaw. The drone was subjected to increasing intensity of blasts, until the drone was destabilized and unable to recover. Analysis of the flight data showed that the drone experienced a sudden change of pressure, on the order of 20 to 40 Pascals, a few tenths of a second prior to major perturbations as measured by the gyroscope and accelerometer. These findings indicate that the barometer detects a pressure change from the vortex prior to the drone destabilizing, allowing a window where preemptive flight maneuvers can be performed to be more resistant to the vortex. These findings offer new insights into UAV sensor fusion and control strategies under impulsive disturb