Design of the High-Payload Flapping Wing Robot E-Flap

Abstract

Autonomous lightweight flapping-wing robots show potential to become a safe and affordable solution for rapidly deploying robots around humans and in complex environments. The absence of propellers makes such vehicles more resistant to physical contact, permitting flight in cluttered environments, and collaborating with humans. Importantly, the provision of thousands of species of birds that have already mastered the challenging task of flapping flight is a rich source of solutions. However, small wing flapping technology is still in its beginnings, with limited levels of autonomy and physical interaction capability with the environment. One significant limitation to this is the low payload available. Here we show the Eagle-inspired Flapping-wing robot E-Flap, a 510g novel design capable of a 100% of payload, exceeding the requirement of the computing and sensing package needed to fly with a high degree of autonomy. The concept is extensively characterized, both in a tracked indoor space and in outdoor conditions. We demonstrate flight path angle of up to 50 • and velocities from as low as 2 m/s to over 6m/s. Overall, the robotic platform has been proven to be reliable, having performed over 100 flights. Through mechanical and electronics advances, the E-Flap is a robust vehicle prototype and paves the way towards flapping-wing robots becoming a practical fully autonomous flying solution. Video attachment: https://youtu.be/GpAa176TMf0.

Design and comparison of tails for bird-scale flapping-wing robots

“…Overall, a C-Tail provides high level of maneuverability and therefore also permits a large range of flight speeds. Low speeds are possible due to the extremely high angles of attack the ornithopter can reach with this tail, as shown in [6]. There are few ornithopters with a C-Tail.…”

“…This is done for both longitudinal and lateral-directional dynamics. All the tests are performed using an Optitrack Motion Capture System and a custom autopilot similar to the one presented in [20] and [6]. The Optitrack consists on 28 infrared cameras which provide measurements of the attitude by roll, pitch and yaw Euler angles (φ, θ, ψ), and position of the CG in the earth reference frame (x E , y E , z E ).…”

“…Complete sizing and manufacture as well as aerodynamics characterization through CFD are reported. Moreover, the inflight performance of three tails is experimentally compared on the E-Flap vehicle [6]. Longitudinal and lateral-directional tests have revealed the strengths and weaknesses between tails, and showed a better overall performance on the V-Tail.…”

Why fly blind? Event-based visual guidance for ornithopter robot flight

“…The required payload for installing the hardware for their proposed vision system was <100 g, which could be carried within the 150 g payload of their robot. Although their system provides a valid solution to some of the problems that arise during flapping-wing flight, increasing the payload often entails that the maneuverability and autonomy are reduced [7]. The work in [5] studied the potential issues and opportunities of using LiDAR, conventional, and event-based vision sensing on board ornithopter robots.…”

“…The scheme closes the control loop fully onboard at rates of 100 Hz in low-cost lightweight hardware. It has been evaluated using the GRIFFIN E-Flap ornithopter [7] in both indoor and outdoor scenarios, see Figures 1 and 3. The contribution of the paper is three-fold: an eventbased line tracking method that enhances the robustness and efficiency of the method presented in [10]; an efficient visual servoing method that exploits event-based vision to perform ornithopter guidance; and the experimental validation in short flapping and gliding maneuvers indoors and outdoors.…”