Control Systems Guide Hypersonic Jets
Ohio State engineers have designed software that can adapt the control systems of unmanned, hypersonic jets to changing conditions during a flight.
Andrea Serrani, associate professor, and Lisa Fiorentini, who received her doctorate in electrical and computer engineering this spring, and Jack McNamara, assistant professor, aerospace engineering, have teamed up with aerospace engineers at the U.S. Air Force Research Laboratory and NASA to develop the control system.
The controller guides the jet along its trajectory and keeps it stable during a flight, Fiorentini explains. Sensors measure factors such as altitude, velocity and acceleration, and the controller calculates whether any adjustments need to be made to keep the jet stable and on course. Then actuators carry out the controller’s commands — for instance, throttling up the engine if the jet needs to accelerate.
The latest supersonic combustion ramjets, called scramjets, scoop oxygen from the air to ignite on-board fuel. Today’s experimental scramjets are not merely supersonic — meaning they fly faster than the speed of sound, or Mach 1 — but hypersonic, meaning they fly at Mach 5 or faster.
“Because these vehicles are unmanned right now, we have to prepare everything ahead of time — anticipate every possible in-flight event,” Fiorentini says. “And the controller has to work really fast. At 10 times the speed of sound, if you lose just one second, the jet has gone far, far off course.”
The Ohio State engineers derived equations that describe a scramjet’s flight dynamics and behavior. Then, given the vehicle model by their partners at Wright-Patterson, they created a set of algorithms that could ultimately be built into a scramjet’s on-board computer.
The technology is under development in military and commercial sectors. Scramjets could deliver missiles to mobile targets; they could also carry people halfway around the world in less than an hour.
The Ohio State and Air Force engineers are continuing to refine the controller. The next improvement will add some safety limits.
Contact:
Andrea Serrani, (614) 292-4976, serrani.1@osu.edu
On the Web: Read more online.
