Friday 20 May 2016

The Future of the UAS



The use of unmanned aircraft systems (UAS) may soon become a status quo for many industries in the world. UAS technology comes in a variety of platforms with different shapes, sizes and capabilities. One of the technology that will be receiving substantial attention is how these UAS systems are being powered up. Currently, most of the consumer based UAS are vertical take-off and landing (VTOL) systems in the form of multicopters. However, these VTOL UAS systems lack the endurance of a typical fixed wing UAS because of the enormous thrust required to move them vertically and they are usually powered by lithium polymer batteries, limiting their effective use. Those using combustion engines use non-renewable fossil fuel that is not sustainable in the long run due to the limited supply, and the carbon emission concerns leading to global warming. 

The article I am sharing relates to the UK-Singapore collaboration to come up with a hydrogen fuel cell that is capable of providing power for an unmanned aircraft (UA) for a 300km non-stop flight. Hydrogen fuel cells from Horizon Energy Systems (HES) of UK is recognized as the world’s longest endurance energy storage systems for electrical UAS (Horizon energy systems; UK-singapore collaboration prepares for record 300km hydrogen fuel cell UAV flight, 2015). Fuel cells from HES contributed to the previous world record of a 128km flight by a 5kg Pterosoar UAS system in 2007. The latest fuel cell from HES that is described in the article, with collaboration from a consortium of Singaporean organizations and HES, achieved the 300km flight in 6 hours with a Skyblade 360 UAS built by ST Aerospace. This was considered a significant milestone as it was the first time that a fuel cell went beyond prototype stage into a standard product list of an UAS manufacturer (Press, 2016). 

The introduction of fuel cells into UAS platforms enhances their versatility and allows other mission possibilities for small low altitude UA previously only realisable by larger and more expensive UAS that flies at higher altitudes.  According to Gonzalez-Espasandin, Leo and Navarro-Arevalo (2014), fuel cells have major advantages in terms of endurance, efficiency, emissions, and stealth “, making them ideal for UAS applications in both military and civilian applications. Fuel cell technology will be a feasible implementation as a clean, efficient, reliable, emission free power source that can be asserted in UAS platforms to make longer flights with the growing magnitude of applications today and in the future.

Reference

Horizon energy systems; UK-singapore collaboration prepares for record 300km hydrogen fuel cell UAV flight. (2015). Energy Weekly News, , 114. Retrieved from http://search.proquest.com.ezproxy.libproxy.db.erau.edu/docview/1710690697?accountid=27203

González-Espasandín, Ó., Leo, T. J., & Navarro-Arévalo, E. (2014). Fuel cells: A real option for unmanned aerial vehicles propulsion. The Scientific World Journal, doi:http://dx.doi.org.ezproxy.libproxy.db.erau.edu/10.1155/2014/497642

Press (2016, February 17). New solid hydrogen-on-demand fuel cell from HES Energy Systems flies ST Aerospace UAV for record 6 hours. sUAS News. Retrieved from http://www.suasnews.com/2016/02/new-solid-hydrogen-on-demand-fuel-cell-from-hes-energy-systems-flies-st-aerospace-uav-for-record-6-hours/

3 comments:

  1. Dear Daniel,

    Good post. You rightly mentioned the hurdle for current UAV is the limitation of battery life. Take DJI Phantom 3 Professional as an example, the Li-Po battery last only 23 minutes (DJI, 2016). Repetitive charging will further shorten its life. Moving forward, it limits the potential of UAV on various application. The post you shared provides solution to current limitations.
    Lastly, can you share more the principle of hydrogen fuel cell?
    - Jin

    Reference:

    DJI. (2016, May 21). Phantom 3 Professional Quick Start Guide. Retrieved from https://dl.djicdn.com/downloads/phantom_3/en/Phantom%203%20Professional%20Quick%20Start%20Guide%20V1.2.pdf

    ReplyDelete
  2. Daniel,
    I fully agree with your concerns of energy sources for UAS. Next to sense and avoid issues, I feel energy is a close second in priorities in the UAS industry. It’s important to note that there are two ways to tackle the energy concerns 1) increased capacity and 2) decreased consumption.

    Fortunately for UAS industry, all industries are searching for ways to decrease consumption. This is typically done by increasing the efficiency of items that are consuming energy. A great example is LED lights. Their reduced energy consumption is greatly impacting the market making the incandescent light bulb a thing of the past.

    On the other hand, increasing capacity, especially through alternative sources of energy is the other approach. This is where the UAS industry can benefit by tapping into the research and development being made in the automotive industry. Companies like Tesla are making strides in the development of battery technology. Others like Mercedes Benz, BMW, Ford, GM, and Volkswagen are making advancements in fuel cell technology utilizing hydrogen.

    While the use of hydrogen sounds like a logical solution as it is the most abundant element on earth, it really requires a deeper investigation. In a very interesting article, Bedard (2005) thoroughly investigated what it takes to go from “well to wheel” for hydrogen in the automotive industry. Unfortunately, most of the energy used to refine hydrogen uses fossil fuels. Because of this, the efficiency created by the use of hydrogen is already lost during its creation. In the end, more emissions are created and energy expended in the production of hydrogen than in the use of gasoline.

    While I agree that energy is a high priority concern for UASs, I’m not sure that hydrogen fuel cell technology is quite ready to be the solution. More efficient way of refining hydrogen are required to really make it a worthwhile alternative.

    Refernece:
    Bedard, P. (2005, October). The case for nuke cars-it’s called ‘hydrogen’. Car and Driver 51(4). Retrieved from http://www.caranddriver.com

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  3. Nice work Dan, your blog looks great

    ReplyDelete