Regarding the 15 gram-weight flapping micro-air-vehicles (FMAVs) or micro ornithopters, how to prolong the operation time and improve the flight control is very critical to their scenario of development. Using the available transducer devices, this work presents four new features for ornithopters and the corresponding feasibility discussion respectively. The 1st feature is repeatable short take-off and landing (re-STOL) so that the ornithopter can automatically land on the ground at times of wind gusts beyond operational bracket, while resetting to an orientation suited for re-take-off. The 2nd feature is to recharge the onboard lithium battery by flexible thin film photo-voltaic (PV) on the tail. The 3rd feature is toward the autonomous flight control of ornithopters. It is realized by integrating gram-weighted micro-controller integrated with MEMS inertial measurement units (IMUs). Orientation control and light-triggered take-off are proposed herein firstly. The 4th feature is to develop new flapping mechanisms with large flap angle with no phase lag between two flapping wings. The above four newly developed features of ornithopters can preliminarily solve their current four shortcomings, i.e., vulnerability to gust wind, short flight endurance, difficulty in autonomous control and small payload.
Journal of Aeronautics, Astronautics and Aviation 47(4), pp.397-406