Experimental Study of Quadrotor Cyclocopter

Recently, a quadrotor cyclocopter that weighs about 13 kg was designed and manufactured. Many components were improved from earlier cyclocopters, including mainframe, power unit, transmission part, hub-spoke structure and rotor control mechanism. Ground and tethered flight tests were conducted prior to the free flight of the vehicle. The test bed, consisting of load cells, a tachometer and a digital power meter, measures vertical and horizontal forces, electric consumed power and rotational speed. The ground tests showed rotor performance and differences between single and multiple rotor cases, while proving a capability of the quadrotor cyclocopter for a free flight. Before the tethered flight tests, a flight control system that executes established attitude control scheme on control mechanism of each rotor was installed on the cyclocopter. Gains of simple PID algorithm embedded in flight control system were adjusted during the tethered flight tests. The quadrotor cyclocopter eventually fulfilled a stable hover and low-speed level flight and showed a great potential for an extended maneuvering capability.