When people debate the coming era of civilian drones, they probably aren’t taking into account the strange thing that happened at a Texas A&M student production of A Midsummer Night’s Dream. Brittany A. Duncan, a doctoral candidate at the university, and her faculty adviser, a professor of computer science and engineering named Robin R. Murphy, were on the team providing technical support for the micro-helicopters and the AirRobot quadcopter-style drone that were used to represent Shakespeare’s fairies. In rehearsals, the actors tended to behave as if the AirRobot—roughly the diameter of a large pizza, with four exposed rotors—were as safe as the fist-size micro-helicopters. So Murphy urged them to think of the AirRobot as “the flying weedwacker of death.” But when audiences also displayed a high level of comfort, she began to wonder whether small drones “are just not scary to people.”
It isn’t an idle question. The Federal Aviation Administration is gearing up to allow commercial drones to fly in U.S. airspace as soon as 2016. That prospect has many people concerned that their privacy will be invaded, along with, perhaps, their personal space. One Colorado man was so alarmed that he recently tried to persuade his town to authorize the bounty hunting of drones.
But in a new study, Duncan and Murphy found that people don’t perceive some drones as invasive at all—which might be a problem, the researchers argue. The subjects’ heart rates failed to register anxiety even when an AirRobot approached just two feet away at roughly head height. That was surprising, because most previous experiments by other researchers showed that people tended to react to earthbound robots by maintaining a personal space of three feet or more, much as with another human. Also contrary to expectation, the test subjects were inclined not to treat the airspace under the drone as if it were occupied. Instead, they reacted as if the drone were roughly as threatening as Tinker Bell.
Why would people steer clear of a robot on the ground but let a flying contraption buzz their heads? Duncan speculates that most of the predators in our evolutionary past would have approached at ground level, not head height. Perhaps small drones bypass our usual defensive response because of a certain birdlike disconnect from terra firma.
To be sure, the test subjects—and this may be what scientists call a “confounding factor”—were an unusually robot-friendly bunch of Texas A&M faculty, staff and students. But if further experimentation bears out the effect, Duncan might become concerned. A few years from now, she says, small drones may be deployed to work crowd control and surveillance at stadium events. In an emergency evacuation, she says, they might also function to direct people away from certain exits, to prevent fatal bottlenecks.
Most small drones can’t broadcast warnings loud enough to be heard in emergencies, Duncan says. But they can buzz back and forth to attract attention, like a bird defending its nest. She is now studying how birds, wasps and even sheepdogs dart into the space of other individuals to steer them, anticipating the day when drones will be “taught” which characteristics of flight will prompt people to move in different ways. What small drones need to know, she says, is, “When can we be happy Tinker Bell? And when should we be Angry Birds?”