GoAERO Stage 1 Winner
US University Innovation Award Winner
Carnegie Mellon University, named for two of the 20th Century's most visionary industrialists and philanthropists – Andrew Carnegie and Andrew Mellon, is renowned around the world for its groundbreaking research and innovative programs and counts among its alumni at least three Nobel laureates in the STEM disciplines of science, technology, engineering, and math.
Growing up near Piper Airport in Lock Haven, PA, Steven Willits would spend hours watching flight tests and general aviation activity, fascinated by the aircraft taking to the sky. Members of his extended family worked at the Piper factory in the 1970s. That early exposure to aviation would eventually lead him to his current role as research scientist at CMU, where he and 15 CMU students form the nucleus of Tartan Air Rescue. As team captain in the global GoAERO challenge to develop a new generation of emergency rescue flyers, Willits and his budding STEM innovators and humanitarians are already forging a distinctive path, earning recognition as one of 11 GoAERO Stage 1 winners and securing funding as one of 14 recipients of NASA's University Innovation project support.
"The GoAERO Prize is a wonderful opportunity to make a difference in society," Willits says. "GoAERO's purpose was the drawing card for the students to not just get a grade for a course but to build a flying ambulance to respond to wildfires, bridge collapses, and other emergencies. Winning Stage 1 and receiving funding is great recognition that we are on the right track. It will help with the costs of the components for our prototype and do early systems testing for Stage 2."
At CMU's Airlab, Willits and Co-Captain Sebastian Scherer are developing their vehicle – the TRAAV-160 (Tartan Rescue Autonomous Air Vehicle). The project will have impact beyond its immediate rescue capabilities. "Like all research and development initiatives at CMU, we are totally committed to building open-source autonomous solutions that benefit humanity," Willits explains.
The project's origins lie in the collaborative spirit of the Airlab. "Sebastian and I have worked together at the Airlab on many small-scale drone programs," Willits relates. "We decided that we should broaden its mission into larger scale initiatives. So, we developed a new course to teach both aerospace and autonomy topics, specifically in the context of the GoAERO requirements, and open it to all CMU students." During the first semester, a full conceptual design process was performed by two teams before a concept and the components necessary to actualize it were selected. Then the two teams were unified to complete the design as their final class project.
This work builds on remarkable advances in autonomous flight technology. Willits notes that autonomous flyers, particularly drones, have become very capable in the past five years, with many advancements in new low SWaP (Size, Weight, and Power) technology. "The Airlab at CMU has been at the center of all this. For example, the research done here on sensor fusion algorithms enables real-time situational awareness in many different and austere environments that rescue aircraft operate in. We have been strongly aligned with search and rescue scenarios by using smaller drones to test in underground environments like caves and mines, and during wildfire scenes where heavy smoke, high winds, and heat envelop the situation. We have also been active in developing new methods for odometry, stereo vision, aircraft detection and tracking, obstacle avoidance, and planning."
Willits brings deep expertise to the project. Before joining the Airlab in 2019, he spent 20 years doing underwater hydrodynamics research for numerous Department of Defense programs and became Head of the Turbomachinery Design department. He also served as an adjunct faculty member in the Department of Aerospace Engineering, teaching courses in Aerodynamics and Flight Mechanics. At the Airlab, he has worked on autonomous aircraft design and performance, drones, ground robots, and several major DARPA programs. He currently leads the technical aspects for several programs – one a large long-range unmanned aerial vehicle with hovering capability, and others involving multi-agent autonomous drones for target surveillance and tracking.
The TRAAV-160 represents the culmination of this expertise: a highway-transportable aircraft ready to deploy within 30 minutes from anywhere in the world. There will be one pilot at a remote station operating the aircraft, which will feature a single turbine engine powered by batteries, and be able to fly at 60 miles per hour with a maximum flight time of 90 minutes.
Looking toward the final Fly-Off, Willits acknowledges the significant technical hurdles ahead. "The largest challenge from a technical perspective is the reliability of the aircraft and autonomy system," he says. "We are often able to achieve good results at smaller scales when the operating scenario is mostly known. Autonomy can be tuned through trial-and-error testing for these cases. The unknown is what bites you." These unknowns include smoke, fog, and even changes in lighting conditions that can severely blind the sensors. "We use behavior trees that dictate what to do in some of these conditions, and the right answer may just be back off and reassess," he notes. "But testing is going to be critical to meet the challenge, and we do not have unlimited time and resources. One major crash could eliminate us, so we must focus on the safety and reliability of the aircraft system."
The team has set ambitious technical goals. Willits hopes that the Tartan Air Rescue team will be able to make it to the final with "a fully capable aircraft to complete all the courses. We will focus on two primary things, a robust and rugged platform that can endure flight for 90 minutes, and more than 80% autonomous flight. To make this a viable commercial unmanned rescue aircraft, there needs to be lots of autonomy. The scenes being encountered will not likely be friendly to aircraft and will have a lot of risk involved, just like helicopter rescue pilots who risk their lives when flying into unknown scenarios. Situational awareness is necessary, but the planning reactions are critical. We must be able to always maintain safe flight going into and out of these rescue areas."
This vision builds on deep institutional expertise. "CMU has an active and long history in developing emergency response robots for disaster scenarios such as nuclear spills, underground search and rescue, urban areas, wildfires, and bridge inspections," Willits says. "So, we see our flyer as a way to advance this history in a new, exciting, and important way."