Multimodal hybrid powerplant for unmanned aerial systemsud(UAS) robotics

摘要

Most UAS propulsion systems currently utilize either Internal Combustion Engines (ICE) or Electric Motorud(EM) prime movers. ICE are favoured for aircraft use due to the superior energy density of fuel compared toudbatteries required for EM, however EM have several significant advantages. A major advantage of EM is thatudthey are inherently self starting have predictable response characteristics and well developed electronic controludsystems. EMs are thus very easy to adapt to automatic control, whereas ICE have more complex controludresponse and an auxiliary starting motor is required for automated starting.udThis paper presents a technique for determining the performance, feasibility and effectiveness of powerplantudhybridisation for small UAS. A Hybrid Powerplant offers the possibility of a radical improvement in theudautonomy of the aircraft for various tasks without sacrificing payload range or endurance capability. In thisudwork a prototype Aircraft Hybrid Powerplant (AHP) was designed, constructed and tested. It is shown that anudadditional 35% continuous thrust power can be supplied from the hybrid system with an overall weight penaltyudof 5%, for a given UAS.udDynamometer and windtunnel results were obtained to validate theoretical propulsion load curves. Usingudmeasured powerplant data and an assumed baseline airframe performance characteristic, theoretical enduranceudcomparisons between hybrid and non-hybrid powerplants were determined. A flight dynamic model for theudAHP was developed and validated for the purposes of operational scenario analysis. Through this simulation itudis shown that climb rates can be improved by 56% and endurance increased by 13%.udThe advantages of implementing a hybrid powerplant have been baselined in terms of payload range andudendurance. Having satisfied these parameters, a whole new set of operational possibilities arises which cannotudbe performed by non-self-starting ICE only powered aircraft. A variety of autonomous robotic aircraft tasksudenabled by the hybrid powerplant is discussed.