Latest Supersonic Scramjets are now guidable, controllable (and hackable?) by software

By Angsuman Chakraborty, Gaea News Network
Thursday, April 30, 2009

ScramjetWASHINGTON - Engineers at the Ohio State University, US, have designed control system software that can effectively guide a hypersonic experimental “scramjet”, which is faster than the speed of sound. Government agencies have been developing faster-than-sound vehicles for decades. The latest supersonic combustion ramjets, called scramjets, burn air for fuel, and could one day carry people to space or around the world in a matter of hours.

The recent success of NASA’s X-43 hypersonic jet has spurred research into the control systems for these vehicles, according to Lisa Fiorentini, doctoral student in electrical and computer engineering at Ohio State University.

She and associate professor Andrea Serrani are developing a new control system in collaboration with the US Air Force Research Laboratory (ARFL) at Wright-Patterson Air Force Base in Ohio.

The scientists report that their controller performed flawlessly in computer simulations of flight maneuvers.

The controller both guides the jet along its trajectory and keeps it stable during a flight, Fiorentini explained.

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.

“Because these vehicles are unmanned right now, we have to prepare everything ahead of time - anticipate every possible in-flight event,” Fiorentini said.

“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,” she added.

What sets the Ohio State control system apart, Serrani explained, is that it allows for flexibility: it adapts to changing conditions during a flight.

“The truly remarkable feature of our approach is that we consider a realistic, physics-based vehicle model within our stability analysis, using a highly sophisticated controller,” he said.

The technology is still 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. (ANI)

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