UNMANNED AIRCRAFT: Cyclocopters Go All-Terrain

Paddlewheel Propulsion.

The U.S. Army’s quest for autonomous reconnaissance aircraft that can fit in the palm of a soldier’s hand has led to a breakthrough in vertical lift technology by researchers utilizing a concept long-known, but never successfully demonstrated: the cyclocopter.

The multi-modal quadrotor cyclocopter developed at the University of Maryland began aquatic mode testing in March. The unmanned aircraft, equipped with plastic foam pontoons, successfully crossed calm water. (Photo via Elena Shrestha)

A cyclocopter is a vertical lift aircraft — but unlike a helicopter — it has at least two rotors, one on either side of the servo and autopilot. A ring of rotor blades extend horizontally like the wings of an airplane and rotate around a horizontal axis, moving in a cycloidal way, like a paddlewheel on a riverboat.

Your 4GWAR editor reports on the latest developments in these tiny unmanned aircraft in the new issue of Vertiflite, a publication of the American Helicopter Society (AHS) International.

In flight, the cyclocopter’s cycloidal rotors and their circular housing look something like a speeding exercise wheel in a hamster cage, but without the hamster. The angle of the rotor blades can be shifted, altering lift and thrust that allows the aircraft to shift seamlessly from vertical to horizontal. The rotating multiple, uniform blades provide the aircraft with 360 degrees of thrust vectoring.

The cyclo rotor concept is over 100 years old with recorded experiments dating back to 1909 but early researchers focused on manned flight and were never able to demonstrate a vehicle that could fly, despite several attempts in the 1930s

Researchers at Texas A&M achieved the world’s smallest cyclocopter, weighing just 29 g (1 oz). (Photo via Moble Benedict)

With funding from the Army Research Laboratory, engineers at the University of Maryland and Texas A&M University have been designing, building and flying unmanned  cyclocopters to demonstrate their agility and viability. At Maryland’s Alfred Gessow Rotorcraft Center, student researchers have built small unmanned cyclocopters ranging in weight from just over two ounces (60 grams) to almost two pounds (900 grams). The largest of the little drones is multi-modal and designed to travel across land and water, as well as the air. At Texas A&M’s Advanced Vertical Flight Laboratory, researchers have also developed a range of increasingly smaller cyclo rotor-powered drones, including one that weighs just 29 grams, currently the smallest ever made.

Anticipating challenging battle environments that U.S. forces will face in future conflicts, the Army Research Lab’s Micro Autonomous Systems and Technology (MAST) program began looking for promising technologies that would provide portable air and ground situational awareness devices for soldiers moving on foot through complex terrain, like dense urban areas. MAST’s Collaborative Technology Alliance (MAST-CTA) was created in 2008 to encourage cooperation among the military, industry and 20 research universities ….

TO READ THE REST OF THE STORY IN THE JULY/AUGUST ISSUE OF VERTIFLITE MAGAZINE, CLICK HERE.