The unmanned helicopter “will work its way through cleared airspace to the field operator,” he says, “then it has to determine if the landing zone requested by the operator is a safe place to land.” This means assessing the slope and surface and detecting any obstacles, such as power lines. “This is easy for a pilot, but it is hard to develop perception technology for a computer to decide.” Perception is the hardest part, he says. “What does a computer do with a 2-D image? That is challenging.”
The requirement is to make an angled approach to a landing at significant speed, not to hover while searching for a safe place to touch down, and to use onboard sensors. “We don't want it to slow down and loiter, we want to be on the ground within five minutes,” says McGinnis. “We want it to get on the ground, avoiding things it detects or where people on the ground say 'Don't go there'.”
Accomplishing the demo will require a tightly integrated suite of sensors, processors and algorithms. “It's a very challenging first demo,” he says. Each contractor's demonstration will involve a series of flights of increasing complexity. “We'll start simple, with no obstacles, then work up to obstacles the aircraft should detect and things like no-fly zones that we tell it to avoid.”
Key goals of Aacus are cost and making the system portable. “We want it to be aircraft-agnostic. We want to take it out of the first helicopter and in a short time put it into another helicopter and have it work as well,” McGinnis says. This is planned for Phase 2; the system is to be installed on the Sikorsky JUH-60A Rascal, a Black Hawk fly-by-wire testbed, for flights in February 2015.
The system must weigh less than 30 lb. “The beauty of this is it has to fit in a helicopter. It can't be too bulky to fit easily in an aircraft, with a lot of margin left over to deliver goods,” he says.
Two further phases are planned under Aacus, which will extend to 2017. Yet to be fully defined, these will involve moving obstacles plus weather and winds, possibly launching from a ship and other capabilities of interest to potential customers, such as casualty evacuation. “There is a lot of sensitivity around this mission, and robotic reliability will have to go way up,” says McGinnis.