Sept. 19 (UPI) -- The risks of drone-human collisions vary widely, researchers at Virginia Polytechnic Institute and State University found in a new comprehensive survey.
If drones are to take on more tasks, including package delivery, traffic management and more, the unmanned aircraft systems will have to fly over humans, raising the risk of drone-human collisions. But what do those risks actually entail? What might they look like?
The latest study offers answers to those questions -- questions regulators at the Federal Aviation Administration and elsewhere are likely to pose as they consider whether or not to grant UASs greater access to airspace.
Using a crash test dummy, Virginia Tech researchers analyzed the potential risk of head and neck injuries posed by three commercially available drones in various impact scenarios. The dummy was outfitted with sensors to measure acceleration and force during the different impacts.
Researchers flew the three aircraft at full speed into the dummy's head at different angles. They also dropped the aircraft onto the dummy's head at various orientations.
Scientists used the acceleration and force measurements to estimate the risk of severe or life-threatening injuries, like a skull fracture. The smallest and lightest of the three drones, weighing just 1.2 kilograms, presented only a 10 percent risk of severe injury. The largest drone, weighing more than 11 kilograms, presented a 70 percent risk.
"There's a wide range of risk," Steven Rowson, an assistant professor of biomedical engineering and mechanics, said in a news release. "In some instances it was low, and in some instances it was high, and there are lessons we can take away from that to reduce injury risk in a deliberate way through product design."
Rowson has previously lead research into the risks of impact scenarios for automotive and sports industries. Rowson and his colleagues hope their findings can help set guidelines for reducing the risk of drone-human collision injuries.
The new analysis -- published this week in the journal Annals of Biomedical Engineering -- suggests injury risks can be mitigated if drones are designed to fracture and break upon impact.
"If you reduce the energy that's able to be transferred to be head, you reduce the injury risk," said doctoral student Eamon Campolettano. "The overarching goal for manufacturers should be to limit energy transfer."
While the latest research suggests there are some smaller drones that are already safe enough to take on commercial duties, the study was less about evaluating specific models and more about establishing a baseline for how to carry out risk assessments for drone-human impacts. In the future, researchers will look more intimately at the risks of different makes and models, as well as the benefits of various risk mitigation strategies.
Risk can't be eliminated entirely. So the questions is: how much risk will the FAA tolerate, and how can companies reduce risks to acceptable levels?
"How much proof does the FAA need before they say, 'Yes, that's okay'?" asked Mark Blanks, director of the Virginia Tech Mid-Atlantic Aviation Partnership. "Once those standards are in place, we're going to see huge expansion in the industry."