Towards Bio-inspired Robotic Aircraft: CPG-based Control of Flapping and Gliding Flight

This paper presents experimental micro aerial vehicle (MAV) research with low-frequency flapping and articulated wing gliding. The importance of phase difference control via an abstract mathematical model of central pattern generators (CPGs) is confirmed with a robotic bat on a 3-DOF pendulum platform. An aerodynamic model for the robotic bat based on the complex wing kinematics is presented. Closed loop experiments show that control dimension reduction is achievable by controlling the phase differences of CPG oscillators. Unstable longitudinal modes are stabilized and controlled using only two control parameters. A transition of flight modes, from flapping to gliding and vice-versa, is demonstrated within the CPG control scheme. The essential elements of perching, which cover the major control aspects of gliding flight, are demonstrated on a robotic MAV equipped with articulated wings. A novel feature of the robotic MAV considered in this paper is that wing dihedral, controlled independently on both wings, is used for yaw control as well as for maintaining the flight path angle.