US Naval Research Laboratory Conducts Flight Tests on Unmanned Sailplanes

By Mike Ball / 07 Jan 2016

Smart Sourcing for Unmanned Systems

Discover cutting-edge solutions from leading global suppliers
SUPPLIER SPOTLIGHT
Follow UST

US Naval Research unmanned sailplaneThe U.S. Naval Research Laboratory (NRL) has announced that, in collaboration with the Air Vehicle Intelligence and Autonomy (AVIA) Lab at Pennsylvania State University (PSU), it has completed testing of cooperative autonomous soaring algorithms used to keep unmanned sailplanes aloft for sustained flight durations – demonstrating the concept of shared soaring data between two unmanned aerial vehicles (UAVs) in flight.

The team launched 23 flights over a nine-day period resulting in greater than 30 hours of combined flight. The tests, conducted within restricted airspace at Phillips Army Airfield, Aberdeen Proving Grounds, culminated with two ‘powered’ sailplanes sharing telemetry data and cooperatively and autonomously soaring at altitudes in excess of one kilometer and for flight durations of over five hours.

The NRL-developed Autonomous Locator of Thermals (ALOFT) autonomous soaring algorithm guided NRL’s aircraft. The PSU aircraft was guided onboard by the AVIA-developed AutoSOAR autonomous soaring algorithm, which drew inspiration from NRL’s ALOFT techniques. AutoSOAR’s addition of a series of atmospheric mapping and collision avoidance algorithms demonstrated in-flight cooperation between the two aircraft on multiple flights.

“Autonomous soaring algorithms seek out naturally occurring areas of rising air called thermals,” said Dr. Dan Edwards, aerospace engineer and principle investigator of the solar-soaring program. “Cooperative autonomous soaring combines data from multiple autonomous soaring aircraft to make a more complete measurement of the local atmospheric conditions. This atmospheric map is then integrated to guide both aircraft toward strong lift activity quicker than if it was just a single aircraft, a technique very similar to that used by a flock of soaring birds.”

Both aircraft demonstrated a robust autonomous soaring capability during the two weeks of testing. PSU’s aircraft flew multiple 2.5-hour flights despite carrying a battery with only enough capacity for four minutes of motor run-time. NRL’s best soaring flight was 5.3 hours while only running a motor-driven propeller for 27 minutes. Both aircraft rode thermals to altitudes in excess of 1,400 meters with several individual climbs in excess of 1,000 meters using nothing more than the power of the atmosphere.

“These tests showed both the NRL and PSU’s autonomous soaring algorithms are successful at finding and using thermals by themselves,” Edwards said. “More importantly, this testing showed proof of concept on multiple occasions, with both aircraft finding thermals and ‘calling’ the other aircraft over to use the same area of lift to increase endurance of the swarm.”

Future testing will focus on reducing the separation distance such that both aircraft can actively soar in the same thermal at the same altitude. The team will also investigate the inclusion of solar photovoltaics to the cooperative autonomous soaring techniques, enabling long endurance flights of unmanned sailplanes using the power of the sun.

Solar photovoltaics will allow conversion of solar radiation directly to electricity to charge batteries or provide power for longer endurance or payloads. NRL is developing “drop-in” power electronics and solar wings, which will enable charging batteries and aiming for overnight flight.

The Solar Photovoltaic and Autonomous Soaring Base Program and the US Marine Corps’ Expeditionary Energy Office Cooperative-Soaring Program are aimed to improve the availability of a 24-7 Information, Surveillance, and Reconnaissance (ISR) mission without using logistics fuel, benefitting the expeditionary warfighter by enhancing the endurance of existing and future UAV assets.

Posted by Mike Ball Mike Ball is our resident technical editor here at Unmanned Systems Technology. Combining his passion for teaching, advanced engineering and all things unmanned, Mike keeps a watchful eye over everything related to the unmanned technical sector. With over 10 years’ experience in the unmanned field and a degree in engineering, Mike’s been heading up our technical team here for the last 8 years. Connect & Contact

Latest Articles

WarrenUAS Secures FAA 44807 Exemption, Expanding Large UAS Training Capabilities

WarrenUAS has received FAA 44807 approval to train students on unmanned aerial systems weighing over 55 pounds in the NAS, placing it among only five U.S. organizations with this clearance, and expanding its national training leadership

May 15, 2025
ARK Electronics Expands Presence on DIU Blue UAS Framework

ARK Electronics' M.2 LTE Module has been added to the DIU Blue UAS Framework, joining other NDAA-compliant components approved for U.S. defense applications

May 15, 2025
ZIYAN Tech to Showcase Unmanned Helicopters at Shenzhen Exhibition

ZIYAN Tech will present their range of unmanned technologies at the Shenzhen International UAV Exhibition, including heavy-lift cargo delivery and long-endurance helicopter UAVs

May 15, 2025
ATAK UAS TOOL Integration for the Vision2 GCS

Vantage Robotics has integrated ATAK and UAS Tool directly into the Vision2 GCS, enabling military operators to control the Vesper drone and manage tactical awareness seamlessly on a single device

May 15, 2025
New High-Energy Lithium-Ion Battery Introduced for VTOL UAVs

T-DRONES has launched the 8S 14.4Ah lithium-ion battery, offering enhanced energy density and long endurance for VTOL UAVs such as the VA17 drone

May 15, 2025
HP to Demonstrate Advanced 3D Printing Innovations at XPONENTIAL 2025

HP Advanced Manufacturing (HP) will exhibit its latest 3D printing technologies for drone and robotics applications at XPONENTIAL 2025

May 15, 2025

Featured Content

Product Spotlight: Durable Lightweight Lithium-Ion Batteries for UAVs

American Lithium Energy (ALE)'s energy-dense lithium-ion battery cells combine high power output with built-in safety features, ideal for UAV and eVTOL applications in challenging environments

May 14, 2025
SAE Media Group Releases Agenda for Counter UAS Middle East & Africa 2025

The inaugural Counter UAS Middle East & Africa 2025 will gather global defense leaders in Amman to explore threats, technologies, and strategies shaping regional drone defense

May 13, 2025
New Tactical Grade IMU from Inertial Labs for UAVs & Guided Munitions

Inertial Labs has launched the IMU-H100, a compact, tactical-grade MEMS IMU designed to enhance precision navigation for UAVs and guided systems

May 08, 2025
Advancing Unmanned Systems Through Strategic Collaboration UST works with major OEMs to foster collaboration and increase engagement with SMEs, to accelerate innovation and drive unmanned systems capabilities forward.