Design and hover testing of a 60-gram cyclocopter Conference Paper uri icon


  • 2015 by the American Helicopter Society International, Inc. All rights reserved. This paper describes the design, controls system development, and hover testing of a 60-gram meso-scale cycloidal- rotor based (cyclocopter) micro air vehicle (MAV). The cycloidal rotor (cyclorotor) is a revolutionary vertical take-off and landing (VTOL) concept with a horizontal axis of rotation. The twin-cyclocopter has a hybrid configuration utilizing two optimized cyclorotors and a horizontal tail rotor used to counteract the pitching moment generated by the cyclorotors and also provide pitch control. Independent rotational speed control of the three rotors and thrust vectoring of the cyclorotors through onboard closed-loop control makes the cyclocopter a highly stable but maneuverable platform. Roll is achieved through differential rpm control and yaw is achieved by thrust vectoring the two cyclorotors. An innovative light-weight and high strength-to-weight ratio blade design significantly reduced cyclorotor weight and improved aerodynamic efficiency. In addition, increasing the virtual camber and incidence (by increasing chord-to- radius ratio) and using a symmetric pitching schedule with a maximum 45 pitching amplitude also improved rotor efficiency. Since the cyclorotors spin in the same direction, there is a net angular momentum that induces a strong gyroscopic coupling between the roll and yaw degrees of freedom. The gyroscopic couplings are eliminated by implementing a careful mixing of roll and yaw inputs on the onboard processor. Due to the fast vehicle dynamics and inherent instability of the cyclocopter, a closed-loop feedback control system was implemented using a custom lightweight autopilot weighing 1.5 grams. The 60 gram meso-scale twin-cyclocopter is currently the smallest cyclocopter in literature to successfully demonstrate stable, sustained hover.

published proceedings

  • American Helicopter Society International - 6th AHS International Specialists' Meeting on Unmanned Rotorcraft System 2015: Platform Design, Autonomy, Operator Workload Reduction and Network Centric Operations

author list (cited authors)

  • Shrestha, E., Martz, V., Yeo, D., Benedict, M., & Chopra, I.

complete list of authors

  • Shrestha, E||Martz, V||Yeo, D||Benedict, M||Chopra, I

publication date

  • January 2015