Hypersonic vehicles, which fly more than five times the speed of sound, are constrained by an important aspect: computational power. Whether they are airplanes, missiles or spacecraft, the super-fast vehicles need to be autonomous, directing their own flight path without human interference. But the difficulty lies in establishing a flexible, accurate and navigable flight trajectory.
Puneet Singla, professor of aerospace engineering in the Penn State College of Engineering, plans to solve this problem. He is the principal investigator on a recently awarded $1.5 million, three-year grant from the United States Department of Defense. The grant is administered by the University Consortium for Applied Hypersonics, which is funded through the Joint Hypersonics Transition Office by the Under Secretary of Defense for Research and Engineering.
The first hypersonic vehicles were developed long ago, Singla explained. The research now underway is to develop the next generation of hypersonic vehicles’ capabilities, which includes autonomous flight.
“We are looking at how to accurately plan their path from one point to another while accounting for multi-physics dynamical models and any path or actuation constraints,” he said. “There are so many mission variables, like the launch point, end point and the flight conditions, which can change rapidly. The next-gen hypersonic vehicles must have the ability to quickly produce a new flight trajectory autonomously.”
To address this, Singla and his team are building and testing in-house algorithms for autonomous flight patterns.
“We are developing computationally-efficient algorithms for the hypersonic vehicles, so that they are no longer constrained by the limits of computer software,” Singla said. “In doing so, we are focusing on the technical areas of navigation, guidance and control of the vehicles. There must also be attention paid to the coupling of aerodynamics, thermodynamics, structural mechanics and propulsive forces.”
The hypersonic flight trajectory simulations are computationally extensive and difficult to achieve, according to Singla. However, he and his team will use new discoveries to assist with the process.
“We will use recent advances in machine learning, system dynamics, uncertainty quantification, sensing and controls to develop new tools to efficiently compute flight trajectories for hypersonic vehicles,” Singla said. “The new trajectory simulation tools are expected to be at least 10 times faster than existing methods.”
Singla noted that algorithms have been used for several engineering applications in the past, like space situational awareness and tracking toxic plumes in the atmosphere or water. The basic research for the development of these algorithms was previously funded by various Department of Defense agencies and the National Science Foundation.
“The algorithms we will develop can be used for aircraft and space control, as they are multibody dynamical systems,” Singla said, describing a multibody system as one system building off one or more systems, such as a space or aircraft carrying a payload.
Graduate students will be a part of the research and development process, according to co-principal investigator Herschel Pangborn, assistant professor of mechanical engineering.
“We’ll train students to be future leaders in this area,” Pangborn said. “They’ll benefit from the experience of a multi-university collaboration, while also working with industry and national labs to transition new technologies from academia to engineering practice.”
As part of the grant, which starts this fall, Penn State will work with researchers from the University of Texas at Austin, Texas A&M University and Sandia National Laboratories. The team has also established collaborations with industry partners Lockheed Martin, the Aerospace Corporation and the Draper Labs.
“Hypersonics is a huge, high-priority initiative within the U.S. Department of Defense, and we will continue to see large amounts of money be made available for many years for relevant research,” said Ned Brokloff, defense research liaison for the Penn State College of Engineering and Applied Research Laboratory. “These awards were very competitive, and Penn State is a relatively new player in this domain, yet the proposal was selected for funding.”