A Simple Model for Gliding and Low-Amplitude Flapping Flight of a Bio-Inspired UAV

Abstract

Inspired by the efficiency of soaring birds in crossing very large distances with barely flap their wings, this work presents a simple model of UAV that, adopting the capabilites of these animals, could improve the existent multi-rotor devices, not only in efficiency but also in safety and accessibility. Thus, simple analytical approximations to reproduce the behavior of flapping wings UAVs are explored, expecting their integration in on-board CPUs to be solved in real-time flight episodes. A comparison between gliding and wing flapping with these models indicates that the thrust generated by wingstrokes should be controlled in further studies in order to mitigate the oscillations along the path of the vehicle. The geometric parameters of the ornithopter are found to be decisive in this sense, so special attention should be paid during the design stage.

Effects of Unsteady Aerodynamics on Gliding Stability of a Bio-Inspired UAV

“…Other works are focused in operations with a deep stall to perform perching, as in [17], [18], although these models are defined for fixed wing gliders more similar to conventional aircrafts. In this sense, previous work in the present project [19] provided a simple solution for the longitudinal steady gliding of a bioinspired UAV.…”

“…In this section, the gliding dynamics of a bio-inspired UAV is formulated. The model used considers two lifting surfaces and the body of the vehicle, and it is based on that of [19], but with some changes in the formulation.…”

“…Note that the mass forces are considered to be applied only in the centre of gravity of the vehicle. Note also that the formulation in the trajectory frame simplifies the force equations in relation to [19], as the lift terms appears only in (1) whereas all the drag terms are in (2). However, (3) is formulated in the body reference frame as it is related to the rotation of the vehicle with the inertial frame.…”

“…The paper is organised as follows. Section II defines the model, including new terms in relation to [19] to better capturing the transitions to the steady state. The effect of these new transient terms are analysed in Section III, considering also the stability modes for both cases, by means of a linearisation of the equations.…”

A Linearized Model for an Ornithopter in Gliding Flight: Experiments and Simulations

“…The system (2)-(5) is solved analytically in steady-state by perturbation methods around a typical gliding flight configuration (β π/2 and θ π/2). It yields from [15]…”