Hybrid propulsion systems for remotely piloted aircraft systems

The development of more efficient propulsion systems for aerospace vehicles is essential to achieve key objectives. These objectives are to increase efficiency while reducing the amount of carbon-based emissions. Hybrid electric propulsion (HEP) is an ideal means to maintain the energy density of hydrocarbon-based fuels and utilize energy-efficient electric machines. A system that integrates different propulsion systems into a single system, with one being electric, is termed an HEP system. HEP systems have been studied previously and introduced into Land, Water, and Aerial Vehicles. This work presents research into the use of HEP systems in Remotely Piloted Aircraft Systems (RPAS). The systems discussed in this paper are Internal Combustion Engine (ICE)-Electric Hybrid systems, ICE-Photovoltaic (PV) Hybrid systems, and Fuel-Cell Hybrid systems. The improved performance characteristics in terms of fuel consumption and endurance are discussed.