Solar UAV for long endurance flights

The project have been done during the four months stay in Lithuania by Marc Olmo and LLibert Chamizo. The aim of the project was to obtain an Unmanned Aerial Vehicle powered by solar energy that was able to flight for as long as possible it within the limitations which are the budget, the time and the technological limitations. During the limited time, the team have been working in all the necessary phases to build a real scale and fully functional Solar UAV. This phases were the following; Theoretical Calculations, Design, Simulation, Building, Tests of the Airframe, Solar Energy Circuit Design and Building 2nd phase tests and Conclusion Obtaining. Through all the process several technical and engineering decisions have been made leading the team to obtain a fully functional 4,4m wingspan fixed wing UAV with a TOW of 5,5 Kg which is perfectly pilotable The final achievements have been a UAV capable of long endurance flight within daytime. The model achieved was able to maintain level, climb and turn perfectly using just the power gathered by the solar cells in its wing. During the development of the project the possibility of the multiday flight have been discussed leading to the conclusion that it's viable but not within the frame of this project. There have been done several tests under actual mission parameters loading the plane with the weight it would be carried during the missions that are most likely solar uav related such as mapping or surveillance. The final result have been correct and lead to an optimistic opinion about the whole Solar UAV paradigm and about the prototype modification and improvement in the near future to achieve even better results (which have been overviewed and planned in the actual report). A fatal error drove the airplane to a nosedive fall with disastrous consequences, the whole project feels and success though it's undoubtable

Multimodal hybrid powerplant for unmanned aerial systems (UAS) robotics

Most UAS propulsion systems currently utilize either Internal Combustion Engines (ICE) or Electric Motor (EM) prime movers. ICE are favoured for aircraft use due to the superior energy density of fuel compared to batteries required for EM, however EM have several significant advantages. A major advantage of EM is that they are inherently self starting have predictable response characteristics and well developed electronic control systems. EMs are thus very easy to adapt to automatic control, whereas ICE have more complex control response and an auxiliary starting motor is required for automated starting. This paper presents a technique for determining the performance, feasibility and effectiveness of powerplant hybridisation for small UAS. A Hybrid Powerplant offers the possibility of a radical improvement in the autonomy of the aircraft for various tasks without sacrificing payload range or endurance capability. In this work a prototype Aircraft Hybrid Powerplant (AHP) was designed, constructed and tested. It is shown that an additional 35% continuous thrust power can be supplied from the hybrid system with an overall weight penalty of 5%, for a given UAS. Dynamometer and windtunnel results were obtained to validate theoretical propulsion load curves. Using measured powerplant data and an assumed baseline airframe performance characteristic, theoretical endurance comparisons between hybrid and non-hybrid powerplants were determined. A flight dynamic model for the AHP was developed and validated for the purposes of operational scenario analysis. Through this simulation it is shown that climb rates can be improved by 56% and endurance increased by 13%. The advantages of implementing a hybrid powerplant have been baselined in terms of payload range and endurance. Having satisfied these parameters, a whole new set of operational possibilities arises which cannot be performed by non-self-starting ICE only powered aircraft. A variety of autonomous robotic aircraft tasks enabled by the hybrid powerplant is discussed

Design, simulation and analysis of a parallel hybrid electric propulsion system for unmanned aerial vehicles

Aerial Vehicles (UAV) has become a significant growing segment of the global aviation industry. These vehicles are developed with the intention of operating in regions where the presence of onboard human pilots is either too risky or unnecessary. Their popularity with both the military and civilian sectors have seen the use of UAVs in a diverse range of applications, from reconnaissance and surveillance tasks for the military, to civilian uses such as aid relief and monitoring tasks. Efficient energy utilisation on an UAV is essential to its functioning, often to achieve the operational goals of range, endurance and other specific mission requirements. Due to the limitations of the space available and the mass budget on the UAV, it is often a delicate balance between the onboard energy available (i.e. fuel) and achieving the operational goals. This paper presents the development of a parallel Hybrid Electric Propulsion System (HEPS) on a small fixed-wing UAV incorporating an Ideal Operating Line (IOL) control strategy. A simulation model of an UAV was developed in the MATLAB Simulink environment, utilising the AeroSim Blockset and the in-built Aerosonde UAV block and its parameters. An IOL analysis of an Aerosonde engine was performed, and the most efficient (i.e. provides greatest torque output at the least fuel consumption) points of operation for this engine were determined. Simulation models of the components in a HEPS were designed and constructed in the MATLAB Simulink environment. It was demonstrated through simulation that an UAV with the current HEPS configuration was capable of achieving a fuel saving of 6.5%, compared to the ICE-only configuration. These components form the basis for the development of a complete simulation model of a Hybrid-Electric UAV (HEUAV)

Power Management Strategy by Enhancing the Mission Profile Configuration of Solar-Powered Aircraft

Solar energy offers solar-powered unmanned aerial vehicle (UAV) the possibility of unlimited endurance. Some researchers have developed techniques to achieve perpetual flight by maximizing the power from the sun and by flying in accordance with its azimuth angles. However, flying in a path that follows the sun consumes more energy to sustain level flight. This study optimizes the overall power ratio by adopting the mission profile configuration of optimal solar energy exploitation. Extensive simulation is conducted to optimize and restructure the mission profile phases of UAV and to determine the optimal phase definition of the start, ascent, and descent periods, thereby maximizing the energy from the sun. In addition, a vertical cylindrical flight trajectory instead of maximizing the solar inclination angle has been adopted. This approach improves the net power ratio by 30.84% compared with other techniques. As a result, the battery weight may be massively reduced by 75.23%. In conclusion, the proposed mission profile configuration with the optimal power ratio of the trajectory of the path planning effectively prolongs UAV operation

Small unmanned airborne systems to support oil and gas pipeline monitoring and mapping

Acknowledgments We thank Johan Havelaar, Aeryon Labs Inc., AeronVironment Inc. and Aeronautics Inc. for kindly permitting the use of materials in Fig. 1.Peer reviewedPublisher PD