In addition to its interest in large and exotic unmanned aircraft, the U.S. Defense Advanced Research Projects Agency (Darpa) is further developing the capabilities of small quadcopters that are familiar to drone enthusiasts. Using a DJI Flamewheel F450 platform, researchers last month completed the first flight tests of Darpa’s Fast Lightweight Autonomy (FLA) program, which aims to produce algorithms that would enable small drones to navigate cluttered indoor environments autonomously.
The FLA program specifies a drone that is small enough to fit through a window and can fly at speeds of up to 20 meters per second—or 45 mph—while navigating complex indoor spaces. It must do so independent of communicating with an outside operator in a GPS-denied environment. Such a drone could assist military patrols in searching dangerous urban settings and emergency responders in reconnaissance of unstable buildings following natural disasters. Focused initially on aircraft, the technology could also have application for ground, marine and underwater systems, Darpa says.
In February, researchers conducted the program’s first data-gathering flights, which validated that the commercial Flamewheel F450 airframe fitted with E600 electric motors, 12-inch propellers and 3D Robotics Pixhawk autopilot can fly up to 20 meters per second while carrying high-definition cameras and other sensors, including light detection and ranging (Lidar), sonar and inertial measurement units.
The testing took place at Otis Air National Guard Base, Mass., in a former aircraft hangar that was organized as a warehouse with simulated walls, boxes and other obstacles to test flight agility and speed. The installation is part of Joint Base Cape Cod, which also hosts a Federal Aviation Administration-designated test site for civil unmanned aircraft. Three teams are participating in the program, using the same quadcopter platform. They are: Draper Laboratory and the Massachusetts Institute of Technology; AeroVironment and Scientific Systems Co.; and the University of Pennsylvania.
“We’re excited that we were able to validate the airspeed goal during this first-flight data collection,” said Mark Micire, Darpa program manager. “The fact that some teams also demonstrated basic autonomous flight ahead of schedule was an added bonus.”
The teams are now tasked with advancing algorithms and onboard computational efficiency to extend the “perception range” of the drone and empower it to make extremely tight turns and abrupt maneuvers at high speeds, Micire said.
“Very lightweight UAVs exist today that are agile and can fly faster than 20 meters per second, but they can’t carry the sensors and computation to fly autonomously in cluttered environments,” he said. “And large UAVs exist that can fly high and fast with heavy computing payloads and sensors on board. What makes the FLA program so challenging is finding the sweetspot of a small size, weight and power air vehicle with limited onboard computing power to perform a complex mission completely autonomously.”