Design, Analysis and Testing of Mechanism to Reduce The Impact on Drones in Failure

Abstract

This work aims at proving the concept of an autorotation-based crash prevention system for drones. The work focuses on quadcopters, whereas the concept can be used for all multi-copters in general with slight modification in design. The system works on the principle of autorotation which is a commonly used method in helicopters for unpowered landing. The autorotation system causes a gyroscopic effect preventing the quadcopter from changing its orientation during fall and also provides drag that helps in reducing the fall velocity. This technique reduces the energy that needs to be absorbed by the quadcopters structure during impact by converting a part of the kinetic energy of fall to the rotational kinetic energy and also creating a profile normal to the local airflow to produce drag. To prove this concept, the terminal velocity of the fall is obtained by mathematical modelling and this is compared with practical results in order to verify the theoretical results. Experimentally, a substantial reduction in velocity was found and this proves that the autorotation mechanism indeed reduces impact during failure in drones.