MIT Lincoln Labs’ toroidal propeller design, an R&D 100 award winner, is significantly quieter than common multirotor propellers while producing comparable thrust.
The innovation is noteworthy as commercial drone delivery begins to increase in many communities around the world. Opponents of drone delivery services have often noted noise pollution as one of their major complaints.
The toroidal propeller design consists of looped blades where each tip of a leading propeller blade is curved back into its trailing propeller blade. This closed structure design minimizes the strength of trailing tip vortices and increases the overall stiffness of the propeller, both of which reduce its noise signature. The design is less likely to catch on or cut objects in its path than conventional propellers. The propeller can be 3-D printed and customized to a wide range of vehicles as an after-market upgrade.
Other MIT 2022 R&D 100 Technologies
MIT had six technologies named to the 2022 R&D 100 list. In addition to the toroidal propellers, two additional award-winning technologies from MIT impact the Counter-UAS and airspace awareness industry.
Airborne Collision Avoidance System sXu
Lincoln Laboratory developed the Airborne Collision Avoidance System sXu (ACAS sXu) to enable unrestricted sUAS operation in the national airspace. The innovation provides a technical solution to enable uncrewed aircraft systems (UAS) to detect and track other nearby aircraft. The ACAS sXu then automatically maneuvers the sUAS away from those aircraft to avoid a potential mid-air collision (or alerts its ground operator to make such a maneuver).
ACAS sXu can be deployed on the sUAS or employed as a remote service and is adaptable across a wide range of sUAS vehicle types. The ACAS sXu design standard was finalized in 2022, and the Federal Aviation Administration (FAA) is developing policies and procedures to approve the use of this system.
Lincoln Laboratory shared this award with its collaborators on the technology: the U.S. Federal Aviation Administration, MITRE, and Johns Hopkins University Applied Physics Laboratory.
Constrained Communications and Radar Dual-Use
Radar and wireless communications systems typically operate in separate radio frequency (RF) bands to avoid cross-interference. The abundance of wireless devices is crowding the RF spectrum. To solve this problem, researchers explored methods for technologies to share the same RF bands to free up space in the RF spectrum.
The Constrained Communications and Radar Dual-Use (CONCORD) technology enables such band sharing. CONCORD is a method of designing waveforms that can perform both radar and communications tasks simultaneously, with the same transmitter and receiver. This method allows a system designer to unify the hardware used for these tasks, simplifying a system’s design and lowering costs. CONCORD has applications for military or commercial systems that need to sense objects with radar and send out data, such as airborne radar imaging systems or self-driving cars.