In attempt to solve the problem of landing drones at sea, under choppy weather conditions, DARPA has replaced fixed, rigid landing gear with flexible legs. An interesting solution, albeit most likely a heavy one. If there is a major impact in weight, that will reduce the flight time, all other variables being equal. Will that limit some of the newly created applications?
If takeoffs and landings are the trickiest parts of flight, then landing at sea, especially in choppy weather, is quite possibly the hardest landing this side of space. One way to improve the outcome of landings at sea is to give pilots more training and experience. Another, explored by DARPA, is to change how the vehicle itself lands. What if, instead of using fixed, rigid landing gear, a helicopter could land on flexible legs?
Flexible legs mean even when it lands on an uneven surface, the helicopter is stable. In flight, these robot legs fold up alongside the copter’s body, giving the appearance of an oversized insect.
DARPA Put Robot Legs On A Helicopter Drone
After testing their new design successfully, the DARPA team has already worked up a list of potential benefits provided by the new landing gear.
“The equipment—mounted on an otherwise unmodified, unmanned helicopter—successfully demonstrated the ability to land and take off from terrain that would be impossible to operate from with standard landing gear,” said Ashish Bagai, DARPA program manager. Bagai described the previously unreleased results of the flight demonstration at Wait, What? A Future Technology Forum, in St. Louis.
Along with comprehensive dynamic simulation and structural analyses, the demonstration flight—conducted near Atlanta—indicated numerous potential benefits, Bagai said, including:
- Reduced risk of damage during hard landings, by as much as a factor of five, compared to conventional landing gear
- Stable landing and takeoff on sloping terrain of up to 20 degrees, more than twice current limits, and on craggy, boulder-strewn or otherwise irregular terrain
- Ship landings in violent sea states
- Significant increase in capabilities with only a modest increase in landing gear weight
The robotic landing gear system was developed with funding from DARPA’s Mission Adaptive Rotor (MAR) program, and is now undergoing continued development by the Georgia Institute of Technology.
As I mentioned earlier, my concern with a design like this would be the weight. When every gram counts to maximize flight time and payload capacity, what will the real world tradeoff be for this design.
Below is a video that shows not only landing simulations but also a proof of concept prototype in action.
As you can see in the video above, the prototype at least, looks very heavy.