scholarly journals Elastic wing deformations mitigate flapping asymmetry during manoeuvres in rose chafers (Protaetia cuprea)

2020 ◽  
Vol 223 (24) ◽  
pp. jeb225599
Author(s):  
Yonatan Meresman ◽  
Gal Ribak
Keyword(s):  
High Speed ◽  
Angle Of Attack ◽  
Biomechanical Model ◽  
Inertial Forces ◽  
Flight Performance ◽  
Free Flight ◽  
Elastic Deformations ◽  
Insect Wings ◽  
Flying Insects ◽  
Intrinsic Musculature

ABSTRACTTo manoeuvre in air, flying animals produce asymmetric flapping between contralateral wings. Unlike the adjustable vertebrate wings, insect wings lack intrinsic musculature, preventing active control over wing shape during flight. However, the wings elastically deform as a result of aerodynamic and inertial forces generated by the flapping motions. How these elastic deformations vary with flapping kinematics and flight performance in free-flying insects is poorly understood. Using high-speed videography, we measured how contralateral wings elastically deform during free-flight manoeuvring in rose chafer beetles (Protaetia cuprea). We found that asymmetric flapping during aerial turns was associated with contralateral differences in chord-wise wing deformations. The highest instantaneous difference in deformation occurred during stroke reversals, resulting from differences in wing rotation timing. Elastic deformation asymmetry was also evident during mid-strokes, where wing compliance increased the angle of attack of both wings, but reduced the asymmetry in the angle of attack between contralateral wings. A biomechanical model revealed that wing compliance can increase the torques generated by each wing, providing higher potential for manoeuvrability, while concomitantly contributing to flight stability by attenuating steering asymmetry. Such stability may be adaptive for insects such as flower chafers that need to perform delicate low-speed landing manoeuvres among vegetation.

scholarly journals Automatic tracking of free-flying insects using a cable-driven robot

2020 ◽  
Vol 5 (43) ◽  
pp. eabb2890 ◽  
Author(s):  
Rémi Pannequin ◽  
Mélanie Jouaiti ◽  
Mohamed Boutayeb ◽  
Philippe Lucas ◽  
Dominique Martinez
Keyword(s):  
High Speed ◽  
Vision System ◽  
Tracking Error ◽  
Parallel Robot ◽  
Flight Behavior ◽  
Agrotis Ipsilon ◽  
Natural Environments ◽  
Free Flight ◽  
Flying Insects ◽  
Online Tracking

Flying insects have evolved to develop efficient strategies to navigate in natural environments. Yet, studying them experimentally is difficult because of their small size and high speed of motion. Consequently, previous studies were limited to tethered flights, hovering flights, or restricted flights within confined laboratory chambers. Here, we report the development of a cable-driven parallel robot, named lab-on-cables, for tracking and interacting with a free-flying insect. In this approach, cameras are mounted on cables, so as to move automatically with the insect. We designed a reactive controller that minimizes the online tracking error between the position of the flying insect, provided by an embedded stereo-vision system, and the position of the moving lab, computed from the cable lengths. We validated the lab-on-cables with Agrotis ipsilon moths (ca. 2 centimeters long) flying freely up to 3 meters per second. We further demonstrated, using prerecorded trajectories, the possibility to track other insects such as fruit flies or mosquitoes. The lab-on-cables is relevant to free-flight studies and may be used in combination with stimulus delivery to assess sensory modulation of flight behavior (e.g., pheromone-controlled anemotaxis in moths).

Measuring the angle of attack of beating insect wings: robust three-dimensional reconstruction from two-dimensional images

1997 ◽  
Vol 200 (21) ◽  
pp. 2693-2704 ◽  
Author(s):  
A Willmott ◽  
C Ellington
Keyword(s):  
High Speed ◽  
Angle Of Attack ◽  
Three Dimensional ◽  
Numerical Algorithms ◽  
Longitudinal Axis ◽  
Wing Motion ◽  
Insect Wings ◽  
High Speed Film ◽  
Dimensional Reconstruction ◽  
Left And Right

A robust technique for determining the angle of attack of insect wings from film of free flight has to date proved elusive. This report describes the development of two new methods ­ the Strips and Planes techniques ­ which were designed to overcome some of the limitations experienced in previous studies. The accuracy and robustness of these novel methods were tested extensively using simulated hawkmoth wing outlines generated for a realistic range of wing positions and torsion. The results were compared with those from two existing methods ­ the Symmetry and Landmarks procedures. The performance of the latter technique will be strongly species-dependent; it could not be successfully applied to hawkmoth flight because of practical difficulties in obtaining suitable landmarks. The Planes method was the least successful of the remaining techniques, especially during those phases of the wingbeat when the orientations of the two wings relative to the camera viewpoint were similar. The Symmetry and Strips methods were tested further to investigate the effects on their performance of introducing additional camber or wing motion asymmetry. The results showed clearly that the Strips method should be the technique of choice wherever the axis of wing torsion is close to the longitudinal axis of the wing. The procedure involves the experimenter matching a model wing divided into chordwise strips to the true wing outline digitized from high-speed film. The use of strips rather than the points digitized in previous studies meant that the analysis required only one wing outline to be digitized. Symmetry of motion between the left and right wings is not assumed. The implications of requiring human input to the Strips method, as opposed to the strictly numerical algorithms of the alternative techniques, are discussed. It is argued that the added flexibility that this provides in dealing with images which have typically been recorded in suboptimal conditions outweighs the introduction of an element of subjectivity. Additional observations arising from the use of the Strips analysis with high-speed video sequences of hawkmoth flight are given.

Dynamic Behaviors of Butterfly Wing and Their Application to Micro Flight Robot

2009 ◽  
Author(s):  
Tadatsugu Imura ◽  
Masaki Fuchiwaki ◽  
Kazuhiro Tanaka
Keyword(s):  
Micro Air Vehicle ◽  
Flight Performance ◽  
Butterfly Wing ◽  
Free Flight ◽  
Elastic Deformations ◽  
Bird Flight ◽  
Dynamic Behaviors ◽  
Practical Applications ◽  
Air Vehicle ◽  
Significant Attention

Micro-Air-Vehicle (MAV) and micro-flight robot using insect and bird flight mechanisms has been attracting significant attention in recent years since the micro-electromechanical systems (MEMS) have been developed actively. Many researchers have attempted to develop MAV and micro-flight robot with various actuators and devices so far however their studies have not led to practical applications yet. One of the reasons is that flying mechanism of birds and insects has not been clarified sufficiently. In this study, we evaluate dynamic behaviors of a wing observed from the butterfly’s viewpoint in its flight. The authors conduct a flight observation experiment of Cynthia cardui performing a free flight and fixed flight and an image analysis and calculate flapping angles, lead-lag angle and feathering angles of the butterfly performing flapping flight to clarify the relation between them. Furthermore, we aim at developing the micro flight robot like the butterfly using these results. The butterfly realizes its flapping motions by changing not only flapping angles but also lead-lag angles in free and fixed flights. In a free flight, a butterfly performs flapping by greatly changing feathering angles in the wing span direction. The micro flapping robot has two wings and does not have the tail plane. The micro flapping robot flied stably for 12 minutes, which was the battery’s duration. The elastic deformations of a wing are one of the important parameters to realize stable flight performance.

Mechanics of Forward Flight in Bumblebees: I. Kinematics and Morphology

1990 ◽  
Vol 148 (1) ◽  
pp. 19-52 ◽  
Author(s):  
R. DUDLEY ◽  
C. P. ELLINGTON
Keyword(s):  
High Speed ◽  
Morphological Analysis ◽  
Angle Of Attack ◽  
Three Dimensional ◽  
Free Flight ◽  
Forward Flight ◽  
Body Angle ◽  
Dimensional Reconstruction ◽  
High Speed Cinematography ◽  
Wing Tip

Using high-speed cinematography, bumblebees in free flight were filmed over a range of forward airspeeds. A detailed description of the wing tip and body kinematics was obtained from a three-dimensional reconstruction of the twodimensional film image. A technique for determining quantitatively the angle of attack of the wing was developed. Kinematic parameters found to vary consistently with airspeed were body angle, stroke plane angle, geometrical angle of attack, and rotational angles of the wings at the ends of half-strokes. Results of a morphological analysis of the wings and bodies of thoseinsects filmed in free flight are presented for use in later calculations of the lift and power requirements of forward flight.

scholarly journals Flight Performance Estimation of Bionic Flapping-Wing Micro Air Vehicle

2018 ◽  
Vol 36 (4) ◽  
pp. 636-643
Author(s):  
Wenqing Yang ◽  
Bifeng Song ◽  
Guanglin Gao
Keyword(s):  
High Speed ◽  
Angle Of Attack ◽  
Estimation Method ◽  
Flapping Wing ◽  
Micro Air Vehicle ◽  
Performance Estimation ◽  
Estimation Methods ◽  
Flight Performance ◽  
Air Vehicle ◽  
Performance Calculation

Bionic flapping-wing micro air vehicle(MAV) has received worldwide attention.The flight performance calculation is an important step in the conceptual design.The differences in performance estimation methods between the flapping-wing and conventional fixed-wing aircraft are analyzed.Based on the results of the aerodynamic estimation and wind tunnel experimental measurement, the flight performance estimation method of flapping-wing micro air vehicle is proposed, and the performance of level flight, climbing, and duration are calculated and analyzed.The frequency represents the accelerator in a certain extent, while the frequency is coupled with lift and thrust.The results show that there may be two stable cruising states at certain frequencies, one is the small angle of attack with high speed, the other is the small speed with big angle of attack, and the two states have different power consumption.According to the parameters of the vehicle, climbing performance and duration performance can be obtained.The speed versus power characteristic curve is a U shape, minimum slope of the U curve can be obtained through the mapping method to calculate the farthest flight speed, and the minimum velocity of U-shaped curve is the speed for longest duration.The proposed flight performance calculation method can be used to evaluate the flight capability of bionic micro flapping-wing air vehicle.

scholarly journals Allometry of wing twist and camber in a flower chafer during free flight: How do wing deformations scale with body size?

2017 ◽  
Vol 4 (10) ◽  
pp. 171152 ◽  
Author(s):  
Yonatan Meresman ◽  
Gal Ribak
Keyword(s):  
Body Size ◽  
Body Mass ◽  
High Speed ◽  
Free Flight ◽  
Trailing Edge ◽  
Adult Body Mass ◽  
Insect Wings ◽  
Wing Chord ◽  
Instantaneous Deformation ◽  
Wing Structure

Intraspecific variation in adult body mass can be particularly high in some insect species, mandating adjustment of the wing's structural properties to support the weight of the larger body mass in air. Insect wings elastically deform during flapping, dynamically changing the twist and camber of the relatively thin and flat aerofoil. We examined how wing deformations during free flight scale with body mass within a species of rose chafers (Coleoptera: Protaetia cuprea ) in which individuals varied more than threefold in body mass (0.38–1.29 g). Beetles taking off voluntarily were filmed using three high-speed cameras and the instantaneous deformation of their wings during the flapping cycle was analysed. Flapping frequency decreased in larger beetles but, otherwise, flapping kinematics remained similar in both small and large beetles. Deflection of the wing chord-wise varied along the span, with average deflections at the proximal trailing edge higher by 0.2 and 0.197 wing lengths compared to the distal trailing edge in the downstroke and the upstroke, respectively. These deflections scaled with wing chord to the power of 1.0, implying a constant twist and camber despite the variations in wing and body size. This suggests that the allometric growth in wing size includes adjustment of the flexural stiffness of the wing structure to preserve wing twist and camber during flapping.

Numerical simulation of high-speed civil transport inlet operability with angle of attack

AIAA Journal ◽  
1998 ◽  
Vol 36 ◽  
pp. 1223-1229
Author(s):  
Ge-Cheng Zha ◽  
Doyle Knight ◽  
Donald Smith ◽  
Martin Haas
Keyword(s):  
Numerical Simulation ◽  
High Speed ◽  
Angle Of Attack

scholarly journals Aerodynamics of inclined cylindrical bodies free-flying in a hypersonic flowfield

2021 ◽  
Vol 62 (9) ◽  
Author(s):  
Patrick M. Seltner ◽  
Sebastian Willems ◽  
Ali Gülhan ◽  
Eric C. Stern ◽  
Joseph M. Brock ◽  
...  
Keyword(s):  
High Speed ◽  
Degrees Of Freedom ◽  
Numerical Data ◽  
Static Stability ◽  
Free Flight ◽  
Aerodynamic Coefficients ◽  
Flow Topology ◽  
Motion Data ◽  
Continuous Rotation ◽  
German Aerospace

Abstract The influence of the flight attitude on aerodynamic coefficients and static stability of cylindrical bodies in hypersonic flows is of interest in understanding the re/entry of space debris, meteoroid fragments, launch-vehicle stages and other rotating objects. Experiments were therefore carried out in the hypersonic wind tunnel H2K at the German Aerospace Center (DLR) in Cologne. A free-flight technique was employed in H2K, which enables a continuous rotation of the cylinder without any sting interferences in a broad angular range from 0$$^{\circ }$$ ∘ to 90$$^{\circ }$$ ∘ . A high-speed stereo-tracking technique measured the model motion during free-flight and high-speed schlieren provided documentation of the flow topology. Aerodynamic coefficients were determined in careful post-processing, based on the measured 6-degrees-of-freedom (6DoF) motion data. Numerical simulations by NASA’s flow solvers Cart3D and US3D were performed for comparison purposes. As a result, the experimental and numerical data show a good agreement. The inclination of the cylinder strongly effects both the flowfield and aerodynamic loads. Experiments and simulations with concave cylinders showed marked difference in aerodynamic behavior due to the presence of a shock–shock interaction (SSI) near the middle of the model. Graphic abstract

scholarly journals Numerical simulation of flapping airfoil with alula

2020 ◽  
Vol 12 ◽  
pp. 175682932097798
Author(s):  
Han Bao ◽  
Wenqing Yang ◽  
Dongfu Ma ◽  
Wenping Song ◽  
Bifeng Song
Keyword(s):  
Aerodynamic Force ◽  
Angle Of Attack ◽  
Leading Edge ◽  
Aerodynamic Performance ◽  
Geometric Parameters ◽  
Flight Performance ◽  
Relative Angle ◽  
Vertical Distance ◽  
Unsteady Effect ◽  
Flapping Airfoil

Bionic micro aerial vehicles have become popular because of their high thrust efficiency and deceptive appearances. Leading edge or trailing edge devices (such as slots or flaps) are often used to improve the flight performance. Birds in nature also have leading-edge devices, known as the alula that can improve their flight performance at large angles of attack. In the present study, the aerodynamic performance of a flapping airfoil with alula is numerically simulated to illustrate the effects of different alula geometric parameters. Different alula relative angles of attack β (the angle between the chord line of the alula and that of the main airfoil) and vertical distances h between the alula and the main airfoil are simulated at pre-stall and post-stall conditions. Results show that at pre-stall condition, the lift increases with the relative angle of attack and the vertical distance, but the aerodynamic performance is degraded in the presence of alula compared with no alula, whereas at post-stall condition, the alula greatly enhances the lift. However, there seems to be an optimal relative angle of attack for the maximum lift enhancement at a fixed vertical distance considering the unsteady effect, which may indicate birds can adjust the alula twisting at different spanwise positions to achieve the best flight performance. Different alula geometric parameters may affect the aerodynamic force by modifying the pressure distribution along the airfoil. The results are instructive for design of flapping-wing bionic unmanned air vehicles.

scholarly journals Aerial course stabilization is impaired in motion-blind flies

2020 ◽  
Author(s):  
Maria-Bianca Leonte ◽  
Aljoscha Leonhardt ◽  
Alexander Borst ◽  
Alex S. Mauss
Keyword(s):  
Motion Detection ◽  
Visual Motion ◽  
Flight Performance ◽  
Wild Type ◽  
Flight Trajectory ◽  
Free Flight ◽  
Motion Vision ◽  
Circling Behaviour ◽  
Course Control ◽  
Self Motion

AbstractVisual motion detection is among the best understood neuronal computations. One assumed behavioural role is to detect self-motion and to counteract involuntary course deviations, extensively investigated in tethered walking or flying flies. In free flight, however, any deviation from a straight course is signalled by both the visual system as well as by proprioceptive mechanoreceptors called ‘halteres’, which are the equivalent of the vestibular system in vertebrates. Therefore, it is yet unclear to what extent motion vision contributes to course control, or whether straight flight is completely controlled by proprioceptive feedback from the halteres. To answer these questions, we genetically rendered flies motion-blind by blocking their primary motion-sensitive neurons and quantified their free-flight performance. We found that such flies have difficulties maintaining a straight flight trajectory, much like control flies in the dark. By unilateral wing clipping, we generated an asymmetry in propulsory force and tested the ability of flies to compensate for this perturbation. While wild-type flies showed a remarkable level of compensation, motion-blind animals exhibited pronounced circling behaviour. Our results therefore unequivocally demonstrate that motion vision is necessary to fly straight under realistic conditions.

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