Indoor autonomous flight of ornithopter using motion capture system

Abstract

PurposeThe purpose of this paper is to perform an indoor autonomous flight of ornithopter using a novel motion capture system.Design/methodology/approachThe ornithopter platform has no on‐board sensors and processors for state estimation or feedback control. Instead, passive markers on the ornithopter body reflect IR light of the multiple strobing CCD cameras, and the position data of the markers are streamed to the ground station in almost real time. Control inputs such as wingbeat frequency and rudder angle are generated by the proportional feedback controllers which are implemented in the ground station and transmitted to the ornithopter. Due to the complexity and nonlinearity of aerodynamics and flexible multibody dynamics, the flight dynamics of ornithopter are difficult to realize in the closed form of state‐space system equations. A controller for stabilizing the flight state variables of ornithopter is not necessary to be implemented by means of flapping counter‐forces and torques which make ornithopter have inherent flight stability. The gains of controllers for following circular trajectories are obtained by a trial‐and‐error approach rather than a model‐based design.FindingsThe autonomous ornithopter successfully circulates the pre‐described radius with the constant altitude and the result shows that control strategies proposed in this study are sufficient to implement the autonomy of ornithopter flight.Originality/valueThe autonomous flight of ornithopter is firstly conducted in a confined indoor environment by using the motion capture system and the control performance is evaluated in terms of position errors.