Hybrid Power Plant Design for a Long-Range Dirigible UAV

Unmanned aerial vehicle (UAV) dirigibles are well suited for surveillance and surveyance missions since they can hover and maintain lift without consuming energy and can be easily deflated for packaging and transportation. The challenge is developing a long endurance system while maintaining a low unit cost. This paper presents a novel hybrid power plant design that addresses both of these requirements. The lightweight design consists of a 4-stroke 14cc gasoline engine in-line with a brushless dc motor/generator and variable pitch propeller capable of producing a maximum power output of 250 W. A method was also developed to compare its performance and endurance to other power plant configurations that could be used in dirigible UAVs. Overall, the proposed hybrid power plant has 674% increase in energy density over that of a purely electric system, thereby proportionally increasing UAV flight time for the same power and weight.