Shape reconstructions and morphing kinematics of an eagle during perching manoeuvres*

Abstract

The key to high manoeuvre ability in bird flight lies in the combined morphing of wings and tail. The perching of a wild Haliaeetus Albicilla without running or wing flapping is recorded and investigated using a high-speed digital video. A shape reconstruction method is proposed to describe wing contours and tail contours during perching. The avian airfoil geometries of the Aquila Chrysaetos are extracted from noncontact surface measurements using a ROMBER 3D laser scanner. The wing planform, chord distribution and twist distribution are fitted in convenient analytical expressions to obtain a 3D wing geometry. A three-jointed arm model is proposed to associate with the 3D wing geometry, while a one-joint arm model is proposed to describe the kinematics of tail. Therefore, a 3D bird model is established. The perching sequences of the wild eagle are recaptured and regenerated with the proposed 3D bird model. A quasi-steady aerodynamic model is applied in the aerodynamic predictions, a four-step Adams–Bashforth method is used to calculate the ordinary differential equations, thus a BFGS based optimization method is established to predict the perching motions.

Bell Shaped Lift Distribution, Aerodynamic Soaring and Control Surface Dynamics of Birds

“…These maneuvers help sustain pitch stability. In order to counter adverse yaw characteristics, the bird performs twisting maneuvers with its tail that enables it to maintain yaw stability [16]. Another maneuver that the bird performs as a stimulus to decrease in lift generation is wing tucking.…”

Quantitative analysis of the morphing wing mechanism of raptors: IMMU-based motion capture system and its application on gestures of a Falco peregrinus

“…[5] Three-dimensional (3D) laser scanners were used to reconstruct the shape of bird wings to analyze kinematics during flight. [6] Because birds use their wings in different ways in different flight movements, their roles in adjusting the position during complicated maneuvering remain largely unknown. At present, there are three main ways to study the flight posture of birds (as shown in Fig.…”

Quantitative analysis of the morphing wing mechanism of raptors: morphing kinematics of Falco peregrinus wing

“…[1][2][3] They can actively change speed and direction, complete cruising, soaring, turning, landing, diving, and other incredible motions. [4][5][6][7] Shatkovska [8] found that birds with different wing morphology have different flight patterns. Liu et al [9] conducted a 3D scanning of the wing geometry of several birds and established a flapping avian wing model with correct kinematics.…”