Development of a Micro Twin-Rotor Cyclocopter Capable of Autonomous Hover

摘要

Growing interest in highly portable versatile flying platforms and recent advancements in microelectronics have led to the development of a scaled-down class of unmanned aerial vehicles known as micro air vehicles (MAVs) . The potential applications of MAVs could range from reconnaissance, terrain mapping, and search and rescue in both military and civilian settings. For these types of missions, hover/low-speed flight capability, high endurance, maneuverability, and the ability to tolerate environmental disturbances such as wind gusts are critical requirements for MAVs. Because MAVs operate in a unique aerodynamic regime (low Reynolds numbers) with a different set of mission requirements and challenges as compared to a full-scale aircraft, it is important to explore novel out-of-the-box vehicle concepts that might have the potential for superior performance at these scales. This note describes the vehicle design and control system development of one such MAV concept: the cyclocopter (shown in Fig. 1). The cyclocopter uses cycloidal rotors (cyclorotors), a horizontal axis propulsion concept that has many advantages such as higher aerodynamic efficiency , maneuverability, and high-speed forward flight capability when compared to a conventional helicopter rotor. A cyclorotor is essentially a rotating-wing system where the span of the blades runs parallel to the axis of its rotation. The pitch angle of each blade is varied cyclically by mechanical means such that the blade experiences positive geometric angles of attack at both the top and bottom halves of the azimuth cycle (Fig. 2). Varying the amplitude and phase of the cyclic blade pitch is used to change the magnitude and direction of the net thrust vector produced by the cyclorotor.