Spherical Shell for Low Altitude UAV Operations: an Impact Analysis

Author

Eric Hettel, Southern Illinois University CarbondaleFollow

Date of Award

8-1-2023

Degree Name

Master of Science

Department

Mechanical Engineering

First Advisor

Eslamiat, Hossein

Abstract

In the past few years, quadcopters have become an innovative way to transfer parcels efficiently over a short distance. Current airspace regulation is slow to adapt to the potential increase in aircraft traffic that will be caused from this. The increase in unmanned aerial vehicles (UAVs) also comes with an increased risk of personal injuries from faulty drones carrying a payload. Many national regulatory agencies rely on the Abbreviated Injury Scale (AIS) to determine the weight threshold of a UAV by evaluating the impact energy and correlating to the severity of a potential injury. This thesis investigates the effectiveness of a passive safety system in the form of a geodesic shell in reduction of head injury in an attempt to reduce the peak impact acceleration and therefore the head injury sustained. The spherical shell is designed as a geodesic sphere with 2V divisions. Its struts are carbon fiber reinforced polymer (CFRP) rods and connectors made from a flexible filament, TPU-95A. The geodesic shell is dropped from a height of 3 meters, varying the payload weight attached to the drone from 2.5lb to 5lb. The impact acceleration is recorded and the impact velocity measured through slow-motion video. The Head Injury Criterion (HIC) scale and the Abbreviated Injury Scale (AIS) is used to measure the predicted head injury level. The results show that this design is ineffective at reducing the head injury level sustained at this particular weight class. However, the test apparatus designed allows for future research to establish a standard of testing and for other geodesic shell designs to be tested for their efficacy at reducing the head injury level sustained.