Conceptual Design and Simulation of a Small Hybrid-Electric Unmanned Aerial Vehicle

TLDR

Parallel hybrid‑electric propulsion offers small UAVs increased endurance, range, and lower acoustic and thermal signatures compared with gasoline‑powered systems. The study presents a conceptual design of a small UAV equipped with a parallel hybrid‑electric propulsion system and a rule‑based controller, along with simulation results. The design couples a cruise‑sized internal combustion engine with an endurance‑sized electric motor and lithium‑ion battery, controlled by a rule‑based scheme derived from ideal operating line concepts. Simulations show the hybrid UAV consumes 54 % less energy on a one‑hour ISR mission and 22 % less on a three‑hour mission than an equivalent gasoline‑powered UAV.

Abstract

Parallel hybrid-electric propulsion systems would be beneficial for small unmanned aerial vehicles used for military, homeland security, and disaster-monitoring missions involving intelligence, surveillance, or reconnaissance (ISR). The benefits include increased time on station and range as compared to electric-powered unmanned aerial vehicles and reduced acoustic and thermal signatures not available with gasoline-powered unmanned aerial vehicles. A conceptual design of a small unmanned aerial vehicle with a parallel hybrid-electric propulsion system, the application of a rule-based controller to the hybrid-electric system, and simulation results are provided. The two-point conceptual design includes an internal combustion engine sized for cruise speed and an electric motor and lithium-ion battery pack sized for endurance speed. A rule-based controller based on ideal operating line concepts is applied to the control of the parallel hybrid-electric propulsion system. The energy use for the 13.6 kg (30 Ib) hybrid-electric unmanned aerial vehicle with the rule-based controller during one-hour and three-hour ISR missions is 54% and 22% less, respectively, than for a four-stroke gasoline-powered unmanned aerial vehicle.