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Innovative fuel cell propulsion technology enabling long endurance for small UAVs

Periodic Reporting for period 2 - UAVEndure II (Innovative fuel cell propulsion technology enabling long endurance for small UAVs)

Reporting period: 2020-06-01 to 2021-01-31

The problem being addressed by UAV ENDURE II: UAV flight time is critical for several mission scenarios, as frequent recharging or refuelling limits the effective availability and service time, as well as range. This has thus far prevented the use of fully electric unmanned aerial vehicles (UAVs), since their performance scales unfavourably with the size/intensity of the UAV operation. Moreover, when small electric UAVs are massively deployed, and particularly in time critical mission, the handling and charging of many battery packs becomes a logistical problem. Thus, manned aerial platforms (helicopters and planes) or large (>25 kg) fixed-wing UAV systems,powered by internal combustion engines (ICE) have been the preferred option for long endurance missions such as monitoring and surveying. However, these large systems present high CAPEX and OPEX, mostly due to the oversized nature of these systems. The unique approach of UAVEndure II project is the combination of two technologies, namely small fixed-wing UAVs and fuel-cell power generation at a downsized scale and price not attempted before. The rationale is to harvest all the benefits of small electric UAVs, while having access to high endurance hitherto only possible with large aerial platforms propelled by ICE.

Impact on society: As UAV are gaining traction the applications are extended beyond the typical task of providing overview to being a central part of the future for logistics/transport, agriculture and environment etc. For the vision of an unmanned infrastructure this to become reality new propulsion technologies are needed. Without this the UAVs will never be able to fulfill the potential for green transition and job creation. The UAVEndure project will extend the flight time from minutes to hours.

The overall objective of UAV ENDURE II is to develop a novel propulsion technology that enable mini fixed winged UAVs to extend the range by a factor of 5-10.
The project is leveraging on novel a fuel cell technology which combines robustness with scalability. The period have been focused on 1) selecting the host platform for the fuel cell technology based on expected weight, size and power output of the fuel cell system and 2 developing a viable method for combining the individual fuel cells into a) 10 stacks and b) combining the 10 stacks into the desired configuration required for providing the required output in the range of 250W. This work have included significant progress on defining the system interfaces for mechanical, hardware and software.
The ability to build robust fuel cell stacks out of the fuel cell tubes is a critical milestone as the operating environment in a UAV is extremely challenging as landing impact and other factors will be though on the mechanical design. Any leaks would render the fuel cell stack unable to provide the required output. Both companies have initiate a recruitment process for additional staff. SKY have already or is the process of employing a 1xmechanical, 2xhardware and 1xembedded engineer. KWT have since the project was launched employed 15 new people (R&D 4, Quality Assurance 7, Production 2, Office 2) people of which a significant part is working directly on the UEII project.