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Trajectory of the wing tips and relationship of the motion parameters during pigeon landing. (a) 1: Definition of the coordinate system of the pigeon’s wing; the coordinate system is defined at the wing root, and the angle between the rib line and the horizontal line is defined as the pitch angle. 2: Motion track of the pigeon’s wing tip in four stages. (b) General relationship between the pitch angle of pigeon wings and the flapping amplitude and swing amplitude of the wing tips (general relationship between each angle error line is the standard error).
Source publication
In the present study, a bionic flapping mechanism of a spatial six-bar configuration was designed to transform a single rotation of a motor into a three degrees of freedom “flapping–twist–swing” cooperative motion of a flapping wing. The kinematics model of the flapping mechanism movement was constructed. The flapping trajectory of the wing based o...
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Citations
... The torque generated by the primaries travels through the wrist to the end of the radius-ulna, and the torque generated by the secondaries travels through the humerus to the shoulder. Therefore, in the above three joints (shoulder, elbow, and wrist), tendons control the contraction of muscles in different parts to promote the motion of different bones [17]. The shoulder mainly executes flapping and swing, and the elbow and wrist mainly execute stretching and twisting, respectively, which form the "twist-swing" motion. ...
The wing is one of the most important parts of a bird’s locomotor system and is the inspiration origination for bionic wing design. During wing motions, the wing shape is closely related to the rotation angles of wing bones. Therefore, the research on the law of bone movement in the process of wing movement can be good guidance for the design of the bionic morphing wing. In this paper, the skeletal posture of the peregrine falcon wing during the extension/flexion is studied to obtain critical data on skeletal posture. Since an elbow joint and a wrist joint rotate correlatively to drive a wing to flex/extend, the wing skeleton is simplified as a four-bar mechanism in this paper. The degree of reproduction of wing skeleton postures was quantitatively analyzed using the four-bar mechanism model, and the bionic wing skeleton was designed. It is found that the wing motions have been reproduced with high precision.
... Hence developed a 6-bar RRSS-SSR (revolute-revolute-spherical-spherical-spherical-spherical-revolute) spatial framework system design linkages to imitate the bionic FW flight. Ji et al. [120] could successfully obtain better transmission with controlled synchrony of the flapping, twisting, and swinging movement of wings. However, the freeness of swing near the wing root was limited, so the model was tested only for "twist-flapping" motion. ...
... When the structural design of the actuation mechanism is defined, theoretical and simulation analysis of the sensitivity of the flap angle and the combination of connection movements will be much important. The measurement of the flapping slope of the crank bar and part of the main wing bar is very relevant as it affects the sensitivity of the flapping angle [120]. Analyzing the influence of various parameters on the movement of the wing or flapping actuation connection at wings is needed. ...
Flying insects are interesting dipteras with an outstanding wing structure that makes their flight efficient. It is challenging to mimic flying insects and create effective artificial flapping drones that can imitate their flying techniques. The smaller insect-size drones have remarkable applications, but they need lightweight and minimal connecting structures for their transmission mechanism. Many operating methods, such as the traditional rotary actuation method and non-conventional oscillatory mechanisms with multiple transmission configurations, are popularly adopted. The classification and recent design innovations with flapping actuation mechanism challenges, particularly bio-inspired (biomimetics) and bio-morphic types of flapping-wing aerial vehicles from micro to pico-scale, are discussed in this review paper. For ease of understanding, we have attempted to depict the actuation mechanisms in the form of block diagrams. The ability of hybrid efficient mechanisms to improve the flapping frequency of wings and flapping actuation design process, including other parameters, such as flapping angle, lift generation, and hovering ability with current driving mechanisms, is also discussed. Depending on their endearing resemblance, we have segregated Flapping-Wing Micro Air Vehicle (FWMAV) design patterns like birds, small birds, nano hummingbirds, moths, bats, biomorphic types, flapping test bench models, and fully flyable models, which are characterized by their flight modes. Important flapping actuation systems that can be used to achieve hovering capability are highlighted. The actuation mechanisms' specifications and configurations are expanded by focusing on the need of flapping frequency and stroke angle controllability via the linkage mechanisms with insight into flapping patterns. Besides that, the requirements for the sustainability of flying patterns during manual and automatic launches were investigated. In addition, the different researchers' annual progress on their Flapping-wing models has been emphasized. The best performing prototypes with their flapping actuation mechanism contributions to achieving better lift and long-duration flight sustainability are articulated through ranking. An insight into some of the significant challenges and future work on flapping performance levels are also discussed.
The use of unmanned aerial vehicle (UAV) in commercial and military fields has risen exponentially. The flapping of birds has always been one of the prominent topics of research. The flapping motion of birds gives the basic idea behind the propulsion of flapping UAV. This work starts with the study of available flapping mechanisms. Followed by the design process based on creative design theory. We have found out an atlas of 10 planar mechanisms with 4, 5, 6, 7 bar linkages. This atlas can be used for design and development of flapping UAV.KeywordsUnmanned aerial vehicleFlappingCreative design theoryPlanar mechanism
This study focuses on the flapping mechanisms found in recently developed biometric flapping-wing air vehicles (FWAVs). FWAVs mimic the flight characteristics of flying animals, providing advantages such as maneuverability, inconspicuousness, and excellent flight efficiency in the low Reynolds number region. The flapping mechanism is a critical part of determining the aerodynamic performance of an FWAV since it is directly related to the wing motion. In this study, the flight characteristics of birds and bats are introduced, the incorporation of these flight characteristics into the development of FWAVs is elucidated, and the utilization of these flight characteristics in the development of FWAVs is explained. Next, the classification and analysis of flapping mechanisms are conducted based on wing motion and the strategy for improving aerodynamic performance. Lastly, the current research gap is elucidated, and potential future directions for further research are proposed. This review can serve as a guide during the early development stage of FWAVs.
The current study involves an experimental as well as numerical study on the aerodynamic behavior of a flapping-wing rotor (FWR) with different feathering amplitudes (−20°-50°, −50°-20°, and −35°-35°). In order to fulfil the experimental test, an FWR which weighs 18.7 g is designed in this manuscript. According to the experimental and numerical results, it was observed that, compared with the cases under a zero average stroke angle, the cases under a positive average stroke angle or negative average stroke angle share a higher rotary speed given the same input voltage. Despite the fact that the negative average stroke angle would facilitate the generation of a higher rotary speed, the negative average stroke angle cases tend to generate the smallest lift-to-power ratio. On the other hand, the cases with a positive average stroke angle tend to share the largest lift-to-power ratio (about 1.25 times those of zero average stroke angle cases and about 1.6 times those of negative average stroke angle cases). The above study indicates that the application of a positive average stroke angle can provide an effective solution to further increase the aerodynamic performance of a bio-inspired FWR.
The article discusses the issues of trajectory control of the movement of a flying robot due to control factors associated with the formation of the aerodynamic force of the biologically inspired movement of the flapping wing of natural analogs—insects. Controlling the movement of a robot with a flapping wing is a complex task and requires the development of mathematical models for the formation of aerodynamic forces resulting from wing oscillations. Under the kinematic and dynamic characteristics, we mean the position, speed and acceleration of the center of mass of the robot and transverse axes, and the forces arising from the wing. These studies will allow collecting information and estimating the forces of interaction of the wing with the air, and then using this information to simulate the movement and control the flight and hovering of a bioinspired mechanical analog. The analysis of the influence of complex laws of motion of the flapping wing, presented in the form of harmonic oscillations, on the formation of aerodynamic force, will allow us to determine the range of parameters at which traction and lifting forces are formed with various varying kinematic and geometric parameters of the bioinsperated flapping wing.
Birds have always fascinated scientists and opened their eyes to new areas of flight mechanisms through biomimicry of these flyers. These flyers can sustain and control the flight through clever maneuvering by flapping their wings. It involves an intricate aerodynamic force production to generate sufficient lift force to overcome the drag and perform useful maneuvers. Development of the forces differs widely among the species due to natural selection of the flyers. As far as the flapping mechanism is considered, it is very efficient. The differences in flight mechanisms may be explored by determining the kinematics, kinetics, and aerodynamics of the flyers. Wing kinematics determines the aerodynamic forces, which vary with flapping speed. The maneuverability and stability are regulated by complex muscle action and neural control allowing the flyer to perform specific tasks. Computational models have emerged as powerful tools to predict the flow around the flyers with potential exploration of the complex interactions between the skeletal system, sensory system, and neural control of the flight.
This article presents a method for analyzing and optimizing a compliant flapping-wing mechanism (CFWM) with the flapping–twist–swing motion for a flapping-wing aerial vehicle (FWAV). Originating from a spatial five-bar rigid linkage to mimic the flapping-wing motion, the CFWM is proposed by replacing two revolute joints with two-segment combined flexible beams and redesigning the spherical joint based on topology structure decomposition. The goal of this work is to minimize the path deviation between the original rigid linkage and the CFWM and the strain energy stored in the CFWM to reduce the needed input power. To this end, first, kinematic and strain energy models of a CFWM are derived utilizing elliptic integral solutions. Next, the optimization of the CFWM is carried out by minimizing the path deviation and strain energy subject to material failures and geometrical constraints, leading to the development of an FWAV. Experimental tests on the output path of the CFWM and the lift/thrust of the FWAV are implemented. The results demonstrate the effectiveness of the derived models in predicting the deflections of the CFWM and the feasibility of applying CFWMs to FWAVs.
