Monday, November 25, 2013

There's been a big uptick in drone research over the last decade

Recently, I was tasked with producing some basic citations on unmanned aerial vehicles, more commonly called drones, for a new grant proposal. As you could imagine, it was not hard to find a cornucopia of papers reflecting the many novel uses for the technology.

What might surprise some, though, was the sheer increase in drone research, how popular these papers are in the academic world, what that research trying to accomplish, and who was funding it.

I did some additional digging on Thompson Reuters Web of Knowledge, searching for articles produced in the last 10 years (2003-2013) that had the keywords "UAV" or "UAS" (Unmanned Aircraft System), and that contained the word "aircraft." The WOK returned 4,184 papers.

At the top of the post is a graph generated by SienceScape, which plotted the number of papers per year. It's pretty, but doesn't give a sense of scale. Below are some bar graphs produced by WOS that better illustrates the trend.

The number of published papers with either UAV or UAS jumped 400%, with just 131 papers in 2003 with those keywords, to 655 papers in 2012. Interestingly, there's been a slight drop in UAV research this year.

Also take a look at the graph on the right (which goes into 2014). Citations have grown from 0 in 2003, to 2,216 in 2012, meaning the substance of these papers is becoming more popular.

So the general topic of drones is becoming more popular, but what about the content of those papers? ScienceScape analyzed keywords of those 4,184 papers and came up with the following graph:

 These are the top 13 keywords from all the UAV/UAS papers over the last decade. Immediately, you can see that the "UAV" acronym is much, much more popular than "UAS." In fact, researchers used UAV as a keyword 23 times more frequently than UAS.

It should be noted that UAS refers to an entire system, meaning the aircraft and ground station. This may just mean that researchers were 23 times more likely to conduct research on the just the aircraft, than they were on the entire system. Nevertheless, it's a telling statistic.

You can, however, tell from the graph that UAS is becoming more popular among researchers.

The frontrunners after UAV and variations thereof? Path planning, followed be remote sensing, followed by navigation, flight, control, and collision avoidance. Path planning and flight control are declining in popularity, while simulation and navigation appear to be on the rise.

The popularity of these research areas might reflect hopes or expectations in the US and abroad to integrate unmanned aircraft among manned aircraft into airspace.

Also becoming more popular among drone researchers is the quadrotor, which is a VTOL aircraft with four spinning blades.

Finally, I took the data about the organizations the funded this research and made a treemap using IBM's Many Eyes app. Any organization that funded more than one paper was included.

Right off the bat, you can see that China is a major player when it comes to drone research. The Natural Science Foundation of China alone has contributed 48 papers in the past decade, and agencies in the country as a whole has contributed 92 papers by my count.

United States agencies funded 80 papers by my count, with 33 papers coming out of National Science Foundation research, and 19 papers coming out of military research agencies (DARPA, Navy and Air Force). Korea also showed up as a strong financier of drone research.

Feel free to splice and remix this data on how you please. I've made public CSV and TXT files for the data behind the SicenceScape keywords visualization and the Many Eyes drone research treemap.