New simulation techniques could help steer unmanned aircraft
Joseph Scott of Clemson University has landed one of the nation’s premier awards for young researchers and will develop new mathematical techniques that could help steer unmanned aircraft.
Scott, an assistant professor of chemical engineering, has received $330,000 as part of the Air Force Office of Scientific Research Young Investigator Program.
The techniques could help autonomous aircraft calculate what trajectory to take to avoid danger without having to play it too safe. The Scott team believes the techniques could also be used for other applications, such as biochemical networks.
“It’s great,” Scott said of winning the award. “It’s very exciting to get support for doing highly theoretical research and to have the opportunity to help the Air Force with a real challenge.”
Scott and his team plan to develop new ways of quickly calculating how to deal with the myriad uncertainties that come from operating in a complex, unpredictable environment.
In flight, for example, wind speed and direction can constantly shift, which would cause problems for an unmanned aircraft trying to avoid an obstacle.
“You’re typically trying to take the shortest path possible, so you tend to cut the corners quite closely,” Scott said. “In reality, an aircraft isn’t going to fly exactly as any model suggests. It’s going to be buffeted by wind in various directions that can’t be predicted exactly, but we can predict the bounds within a reasonable range.
“The models we are developing would provide a tube that surrounds all of the possible trajectories, taking these disturbances into account. If I know that, then I can decide how far you need to back off of an obstacle so that a gust of wind can’t cause a collision.”
Douglas E. Hirt, chair of the Department Chemical and Biomolecular Engineering, congratulated Scott on the award.
“This is one of the highest awards that young researchers can win,” Hirt said. “It affirms that Dr. Scott shows exceptional promise and ability in doing research. The award is highly deserved, and we’re please that he is at Clemson.”
Scott said that he hopes the techniques he and his team are developing would replace current methods that are too slow, expensive, or conservative to be of practical use.
The team is working to cheaply produce a mathematical “enclosure” of tens of thousands of trajectories that would result from different scenarios. It would remove the need to calculate all of those trajectories, he said.
“Our methods for doing this typically take around a hundredth of a second,” Scott said. “In that time you could simulate about 100 scenarios, which is not nearly enough in many cases.
“If I’m flying along a trajectory, the wind a second after I start is different than two seconds after I start, which is different at three seconds. I’ve got uncertainty at every point in time along that trajectory. You can come up with endless combinations. When you have uncertainties that can take so many different values, the number of possibilities you have to check grows exponentially.”
Scott joined Clemson in August 2013 after receiving master’s and Ph.D. degrees from the Massachusetts Institute of Technology.
He began developing the models for chemical engineering applications, but Scott expects the models will translate well to the Air Force’s flight needs.
“Computer models are very diverse, but if you take broad strokes, they fall into one of a few buckets based on what kind of equations you’re solving,” Scott said. “In this case, they are ordinary differential equations, and they model a huge variety of physical systems.
“You can write the flight dynamics of an airplane, and you can write the kinetics of a chemical reaction. It’s a very general class of model. Our techniques are useful for anything that has uncertainties in the model, which is pretty much all models.”
Anand Gramopadhye, dean of the College of Engineering and Science, said that Scott’s award is a testament to the creative approach he takes to his work.
“Congratulations to Dr. Scott,” Gramopadhye said. “It shows the high level of scholarship he brings to Clemson and underscores that he is among a growing cadre of top young researchers who are clustering at Clemson.”