scholarly journals A Modified Quasisteady Aerodynamic Model for a Sub-100 mg Insect-Inspired Flapping-Wing Robot

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Chenyang Wang ◽  
Weiping Zhang ◽  
Junqi Hu ◽  
Jiaxin Zhao ◽  
Yang Zou
Keyword(s):  
High Speed ◽  
Aerodynamic Force ◽  
Flapping Wing ◽  
High Speed Photography ◽  
Wing Kinematics ◽  
Blade Element Theory ◽  
Passive Rotation ◽  
Aerodynamic Model ◽  
Proposed Model ◽  
Element Theory

This study proposes a modified quasisteady aerodynamic model for the sub-100-milligram insect-inspired flapping-wing robot presented by the authors in a previous paper. The model, which is based on blade-element theory, considers the aerodynamic mechanisms of circulation, dissipation, and added-mass, as well as the inertial effect. The aerodynamic force and moment acting on the wing are calculated based on the two-degree-of-freedom (2-DOF) wing kinematics of flapping and rotating. In order to validate the model, we used a binocular high-speed photography system and a customized lift measurement system to perform simultaneous measurements of the wing kinematics and the lift of the robot under different input voltages. The results of these measurements were all in close agreement with the estimates generated by the proposed model. In addition, based on the model, this study analyzes the 2-DOF flapping-wing dynamics of the robot and provides an estimate of the passive rotation—the main factor in generating lift—from the measured flapping kinematics. The analysis also reveals that the calculated rotating kinematics of the wing under different input voltages accord well with the measured rotating kinematics. We expect that the model presented here will be useful in developing a control strategy for our sub-100 mg insect-inspired flapping-wing robot.

Implementation of initial passive stability in insect-mimicking flapping-wing micro air vehicle

2015 ◽  
Vol 3 (1) ◽  
pp. 18-38 ◽  
Author(s):  
Hoang Vu Phan ◽  
Quang-Tri Truong ◽  
Hoon-Cheol Park
Keyword(s):  
Aerodynamic Force ◽  
Three Dimensional ◽  
Flapping Wing ◽  
Micro Air Vehicle ◽  
Content Type ◽  
Wing Kinematics ◽  
Blade Element Theory ◽  
Air Vehicle ◽  
The Mean ◽  
Vertical Takeoff

Purpose – The purpose of this paper is to demonstrate the uncontrolled vertical takeoff of an insect-mimicking flapping-wing micro air vehicle (FW-MAV) of 12.5 cm wing span with a body weight of 7.36 g after installing batteries and power control. Design/methodology/approach – The forces were measured using a load cell and estimated by the unsteady blade element theory (UBET), which is based on full three-dimensional wing kinematics. In addition, the mean aerodynamic force center (AC) was determined based on the UBET calculations using the measured wing kinematics. Findings – The wing flapping frequency can reach to 43 Hz at the flapping angle of 150°. By flapping wings at a frequency of 34 Hz, the FW-MAV can produce enough thrust to over its own weight. For this condition, the difference between the estimated and average measured vertical forces was about 7.3 percent with respect to the estimated force. All parts for the FW-MAV were integrated such that the distance between the mean AC and the center of gravity is close to zero. In this manner, pitching moment generation was prevented to facilitate stable vertical takeoff. An uncontrolled takeoff test successfully demonstrated that the FW-MAV possesses initial pitching stability for takeoff. Originality/value – This work has successfully demonstrated an insect-mimicking flapping-wing MAV that can stably takeoff with initial stability.

scholarly journals Operation of the alula as an indicator of gear change in hoverflies

2011 ◽  
Vol 9 (71) ◽  
pp. 1194-1207 ◽  
Author(s):  
Simon M. Walker ◽  
Adrian L. R. Thomas ◽  
Graham K. Taylor
Keyword(s):  
High Speed ◽  
Aerodynamic Force ◽  
Angular Acceleration ◽  
The State ◽  
The Body ◽  
Kinematic Parameters ◽  
Wing Kinematics ◽  
Change Mechanism ◽  
The Third ◽  
Gear Change

The alula is a hinged flap found at the base of the wings of most brachyceran Diptera. The alula accounts for up to 10 per cent of the total wing area in hoverflies (Syrphidae), and its hinged arrangement allows the wings to be swept back over the thorax and abdomen at rest. The alula is actuated via the third axillary sclerite, which is a component of the wing hinge that is involved in wing retraction and control. The third axillary sclerite has also been implicated in the gear change mechanism of flies. This mechanism allows rapid switching between different modes of wing kinematics, by imposing or removing contact with a mechanical stop limiting movement of the wing during the lower half of the downstroke. The alula operates in two distinct states during flight—flipped or flat—and we hypothesize that its state indicates switching between different flight modes. We used high-speed digital video of free-flying hoverflies ( Eristalis tenax and Eristalis pertinax ) to investigate whether flipping of the alula was associated with changes in wing and body kinematics. We found that alula state was associated with different distributions of multiple wing kinematic parameters, including stroke amplitude, stroke deviation angle, downstroke angle of incidence and timing of supination. Changes in all of these parameters have previously been linked to gear change in flies. Symmetric flipping of the alulae was associated with changes in the symmetric linear acceleration of the body, while asymmetric flipping of the alulae was associated with asymmetric angular acceleration of the body. We conclude that the wings produce less aerodynamic force when the alula is flipped, largely as a result of the accompanying changes in wing kinematics. The alula changes state at mid-downstroke, which is the point at which the gear change mechanism is known to come into effect. This transition is accompanied by changes in the other wing kinematic parameters. We therefore find that the state of the alula is linked to the same parameters as are affected by the gear change mechanism. We conclude that the state of the alula does indeed indicate the operation of different flight modes in Eristalis , and infer that a likely mechanism for these changes in flight mode is the gear change mechanism.

scholarly journals Trajectory Estimation of Hypersonic Glide Vehicle Based on Analysis of Aerodynamic Performance

2019 ◽  
Vol 37 (6) ◽  
pp. 1102-1110
Author(s):  
Yunpeng Cheng ◽  
Xiaodong Yan ◽  
Feng Cheng
Keyword(s):  
High Speed ◽  
Engineering Calculation ◽  
Aerodynamic Performance ◽  
The State ◽  
Aerodynamic Parameter ◽  
Trajectory Estimation ◽  
Aerodynamic Model ◽  
Proposed Model ◽  
Improve Accuracy ◽  
Nonlinear Aerodynamic

Due to high speed and high maneuverability of hypersonic glide vehicles (HGVs), the state estimation of such targets has always been a research hotspot. In order to improve accuracy of the trajectory estimation, a nonlinear aerodynamic parameter model for target estimation based on aerodynamic performance analysis is proposed. Firstly, the dynamic characteristics of the hypersonic glide vehicle during the hypersonic gliding stage was analyzed. Then, aiming at HTV-2-liked vehicle, the engineering calculation method was used to form the reference aerodynamic model for the target estimation. Secondly, a deviation model described by first-order Markov process was introduced to compensate the uncertainties of the unknown maneuver information from the target. Finally, extended Kalman filter was utilized to estimate the state of the target. The simulation results show that the proposed model is able to improve the accuracy of acceleration estimation for the HTV-2-liked hypersonic gliding vehicles.

Effects of stretch receptor ablation on the optomotor control of lift in the hawkmothManduca sexta

2001 ◽  
Vol 204 (21) ◽  
pp. 3683-3691 ◽  
Author(s):  
Mark A. Frye
Keyword(s):  
Action Potentials ◽  
High Speed ◽  
Visual Cues ◽  
Aerodynamic Force ◽  
Video Recording ◽  
Force Production ◽  
Stretch Receptor ◽  
Flight Behavior ◽  
Wing Kinematics ◽  
Control Flight

SUMMARYIn insects, fast sensory feedback from specialized mechanoreceptors is integrated with guidance cues descending from the visual system to control flight behavior. A proprioceptive sensory organ found in both locusts and moths, the wing hinge stretch receptor, has been extensively studied in locusts for its powerful influence on the activity of flight muscle motoneurons and interneurons. The stretch receptor fires a high-frequency burst of action potentials near the top of each wingstroke and encodes kinematic variables such as amplitude and timing. Here, I describe the effects of stretch receptor ablation on the visual control of lift during flight in the hawkmoth Manduca sexta. Using a combination of extracellular muscle recordings, force and position measurements and high-speed video recording, I tracked power muscle activity, net vertical flight force (lift), abdomen deflection and wing kinematics in response to image motions of varying velocity during tethered flight in a wind tunnel. As a result of bilateral ablation of the wing hinge stretch receptors, visually evoked lift decreased to nearly one-third of that exhibited by intact animals. The phase and frequency of indirect power muscle action potentials and the patterns of abdominal deflection were unaffected; however, wingstroke amplitude was clearly reduced after ablation. Collectively, these results suggest that stretch receptor feedback is integrated with descending visual cues to control wing kinematics and the resultant aerodynamic force production during flight.

scholarly journals Research on Physics of Photography: A Bibliometric Study (2000-2020)

2021 ◽  
Vol 2110 (1) ◽  
pp. 012017
Author(s):  
N Suprapto ◽  
A Kholiq ◽  
B K Prahani ◽  
U A Deta
Keyword(s):  
Key Words ◽  
Bibliometric Analysis ◽  
High Speed ◽  
Future Research ◽  
High Speed Photography ◽  
Vos Viewer ◽  
Search Results ◽  
The Third ◽  
Proposed Model ◽  
Scopus Database

Abstract The purpose of this study is to analyse physics on photography research and see its trends to find the opportunity for further research. A bibliometric analysis was used in this study. The search results from the Scopus database were extracted using the VOS viewer software. A total of 432 documents related to physics of photography were analysed and mapped. The results mapped the trend of documents across years, language, countries, affiliation, type, sources, authors, and key words. The results have also indicated two major clusters and one minor cluster in researching on physics of photography. The first cluster (green colour) was photography as an application. The second cluster (red) was photography specified into high-speed photography and modern photography. The third cluster (blue) was technology of photography in connecting with competition. A proposed model for future research is also illustrated. Thus, it can be an opportunity for further researchers to conduct research related to this area.

scholarly journals Deformable wing kinematics in the desert locust: how and why do camber, twist and topography vary through the stroke?

2008 ◽  
Vol 6 (38) ◽  
pp. 735-747 ◽  
Author(s):  
Simon M. Walker ◽  
Adrian L. R. Thomas ◽  
Graham K. Taylor
Keyword(s):  
Flight Control ◽  
High Speed ◽  
Schistocerca Gregaria ◽  
Aerodynamic Force ◽  
Angle Of Attack ◽  
Force Production ◽  
Linear Increase ◽  
Trailing Edge ◽  
Wing Kinematics ◽  
Drag Ratio

Here, we present a detailed analysis of the wing kinematics and wing deformations of desert locusts ( Schistocerca gregaria , Forskål) flying tethered in a wind tunnel. We filmed them using four high-speed digital video cameras, and used photogrammetry to reconstruct the motion of more than 100 identified points. Whereas the hindwing motions were highly stereotyped, the forewing motions showed considerable variation, consistent with a role in flight control. Both wings were positively cambered on the downstroke. The hindwing was cambered through an ‘umbrella effect’ whereby the trailing edge tension compressed the radial veins during the downstroke. Hindwing camber was reversed on the upstroke as the wing fan corrugated, reducing the projected area by 30 per cent, and releasing the tension in the trailing edge. Both the wings were strongly twisted from the root to the tip. The linear decrease in incidence along the hindwing on the downstroke precisely counteracts the linear increase in the angle of attack that would otherwise occur in root flapping for an untwisted wing. The consequent near-constant angle of attack is reminiscent of the optimum for a propeller of constant aerofoil section, wherein a linear twist distribution allows each section to operate at the unique angle of attack maximizing the lift to drag ratio. This implies tuning of the structural, morphological and kinematic parameters of the hindwing for efficient aerodynamic force production.

scholarly journals Experimental Study on Flexible Deformation of a Flapping Wing with a Rectangular Planform

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Wenqing Yang ◽  
Jianlin Xuan ◽  
Bifeng Song
Keyword(s):  
High Speed ◽  
Aerodynamic Force ◽  
Inertial Force ◽  
Aerodynamic Characteristics ◽  
Flapping Wing ◽  
Image Correlation ◽  
Flapping Wings ◽  
Aerodynamic Forces ◽  
Cyclic Movements ◽  
Flexible Deformation

A flexible flapping wing with a rectangular planform was designed to investigate the influence of flexible deformation. This planform is more convenient and easier to define and analyzed its deforming properties in the direction of spanwise and chordwise. The flapping wings were created from carbon fiber skeleton and polyester membrane with similar size to medium birds. Their flexibility of deformations was tested using a pair of high-speed cameras, and the 3D deformations were reconstructed using the digital image correlation technology. To obtain the relationship between the flexible deformation and aerodynamic forces, a force/torque sensor with 6 components was used to test the corresponding aerodynamic forces. Experimental results indicated that the flexible deformations demonstrate apparent cyclic features, in accordance with the flapping cyclic movements. The deformations in spanwise and chordwise are coupled together; a change of chordwise rib stiffness can cause more change in spanwise deformation. A certain lag in phase was observed between the deformation and the flapping movements. This was because the deformation was caused by both the aerodynamic force and the inertial force. The stiffness had a significant effect on the deformation, which in turn, affected the aerodynamic and power characteristics. In the scope of this study, the wing with medium stiffness consumed the least power. The purpose of this research is to explore some fundamental characteristics, as well as the experimental setup is described in detail, which is helpful to understand the basic aerodynamic characteristics of flapping wings. The results of this study can provide an inspiration to further understand and design flapping-wing micro air vehicles with better performance.

scholarly journals Aerodynamic investigation on shifted-back vertical stroke plane of flapping wing in forward flight

2021 ◽  
Vol 16 (6) ◽  
pp. 064001
Author(s):  
Jong-Seob Han ◽  
Christian Breitsamter
Keyword(s):  
Time Course ◽  
Leading Edge ◽  
Aerodynamic Characteristics ◽  
Flapping Wing ◽  
Forward Flight ◽  
Blade Element Theory ◽  
Aerodynamic Model ◽  
Edge Vortex ◽  
Perpendicular Component ◽  
Semi Empirical

Abstract In order to properly understand aerodynamic characteristics in a flapping wing in forward flight, additional aerodynamic parameters apart from those in hover—an inclined stroke plane, a shifted-back stroke plane, and an advance ratio—must be comprehended in advance. This paper deals with the aerodynamic characteristics of a flapping wing in a shifted-back vertical stroke plane in freestream. A scaled-up robotic arm in a water towing tank was used to collect time-varying forces of a model flapping wing, and a semi-empirical quasi-steady aerodynamic model, which can decompose the forces into steady, quasi-steady, and unsteady components, was used to estimate the forces of the model flapping wing. It was found that the shifted-back stroke plane left a part of freestream as a non-perpendicular component, giving rise to a time-course change in the aerodynamic forces during the stroke. This also brought out two quasi-steady components (rotational and added-mass forces) apart from the steady one, even the wing moved with a constant stroke velocity. The aerodynamic model underestimated the actual forces of the model flapping wing even it can cover the increasingly distributed angle of attack of the vertical stroke plane with a blade element theory. The locations of the centers of pressure suggested a greater pressure gradient and an elongated leading-edge vortex along a wingspan than that of the estimation, which may explain the higher actual force in forward flight.

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