scholarly journals A CFD-informed quasi-steady model of flapping-wing aerodynamics

2015 ◽  
Vol 783 ◽  
pp. 323-343 ◽  
Author(s):  
Toshiyuki Nakata ◽  
Hao Liu ◽  
Richard J. Bomphrey
Keyword(s):  
Aerodynamic Force ◽  
Element Model ◽  
Flapping Wing ◽  
Tip Vortex ◽  
Unmanned Aerial Systems ◽  
Aerodynamic Forces ◽  
Cfd Modelling ◽  
And Control ◽  
Aerial Systems ◽  
Wing Aerodynamics

Aerodynamic performance and agility during flapping flight are determined by the combination of wing shape and kinematics. The degree of morphological and kinematic optimization is unknown and depends upon a large parameter space. Aimed at providing an accurate and computationally inexpensive modelling tool for flapping-wing aerodynamics, we propose a novel CFD (computational fluid dynamics)-informed quasi-steady model (CIQSM), which assumes that the aerodynamic forces on a flapping wing can be decomposed into quasi-steady forces and parameterized based on CFD results. Using least-squares fitting, we determine a set of proportional coefficients for the quasi-steady model relating wing kinematics to instantaneous aerodynamic force and torque; we calculate power as the product of quasi-steady torques and angular velocity. With the quasi-steady model fully and independently parameterized on the basis of high-fidelity CFD modelling, it is capable of predicting flapping-wing aerodynamic forces and power more accurately than the conventional blade element model (BEM) does. The improvement can be attributed to, for instance, taking into account the effects of the induced downwash and the wing tip vortex on the force generation and power consumption. Our model is validated by comparing the aerodynamics of a CFD model and the present quasi-steady model using the example case of a hovering hawkmoth. This demonstrates that the CIQSM outperforms the conventional BEM while remaining computationally cheap, and hence can be an effective tool for revealing the mechanisms of optimization and control of kinematics and morphology in flapping-wing flight for both bio-flyers and unmanned aerial systems.

scholarly journals Controlling the Operation Process of the Unmanned Aerial System

2017 ◽  
Vol 44 (1) ◽  
pp. 5-36
Author(s):  
Leszek Ułanowicz ◽  
Michał Jóźko ◽  
Paweł Szczepaniak
Keyword(s):  
Technical Condition ◽  
Unmanned Aerial Systems ◽  
Unmanned Aerial System ◽  
Operation System ◽  
Mutual Relation ◽  
Operation Process ◽  
Credible Information ◽  
Technical Operation ◽  
And Control ◽  
Aerial Systems

Abstract The development of unmanned aerial systems (UAS) encountered the problem of controlling the process of technical operation. The literature that is available to the authors lacks credible information concerning the principles of specifying the strategy and control of the process of UAS operation. Hence, it is necessary to recognise and interpret the basic UAS operation features. The purpose of the publication is to present the properties of the UAS as an object of operation and the mutual relation of the technical operation process with the UAS’ technical condition alteration process. We present the results of analyses in terms of functionality and the UAS’ utility potential. The publication pays special attention to the properties of the UAS as an object of operation. The paper includes the analysis of the UAS operation principles and the specification of the advantage and disadvantage of those principles, i.e. using a non-repairable UAS until damaged, using a repairable UAS until damaged, periodical technical servicing, continuous diagnostic operation. The proposals for the control models in the UAS operation system have also been included.

Unmanned aerial systems: autonomy, cognition, and control

2021 ◽  
pp. 47-80
Author(s):  
Allahyar Montazeri ◽  
Aydin Can ◽  
Imil Hamda Imran
Keyword(s):  
Unmanned Aerial Systems ◽  
And Control ◽  
Aerial Systems

Explicit Aerodynamic Model Characterization of a Multirotor Unmanned Aerial Vehicle in Quasi-Steady Flight

2020 ◽  
Vol 15 (8) ◽  
Author(s):  
Carlos Rodríguez de Cos ◽  
José Ángel Acosta
Keyword(s):  
Controller Design ◽  
Control Strategies ◽  
Computational Cost ◽  
Unmanned Aerial Systems ◽  
Nonlinear Phenomena ◽  
Aerodynamic Forces ◽  
Aerodynamic Model ◽  
Potential Applications ◽  
Aerial Vehicle ◽  
Aerial Systems

Abstract In the last years, the research on unmanned aerial systems (UASs) has shown a marked growth and the models to simulate UASs have been deeply studied. Although onboard controller algorithms have increased their complexity, most of them still rely on simplistic models. In essence, aerodynamic forces/torques are generally considered either insignificant compared to propulsion and inertial forces or acceptably modeled with constant aerodynamic coefficients estimated in a particular flight regime. However, the increase of power in the onboard computers allows to make controller algorithms more complex, and therefore, to increase the total performance of the UAS. In this regard, this work provides an explicit aerodynamic model for multirotor UAS that, unlike most of the current models, does not need iterations to be adjusted to the flight conditions at a higher computational cost. This explicit nature makes it an excellent choice for being implemented in onboard computers, thus covering a broad range of applications, from controller design to numerical analysis (e.g., the capture nonlinear phenomena like bifurcations). To obtain this accurate explicit mathematical aerodynamic model, a thorough analysis of a batch of simulations is carried out. In these simulations, the aerodynamic forces and torques are estimated using computer fluid dynamics (CFD), and the propulsive effects are taken into account via blade element momentum theory (BEMT). A study of its implementation for different regimes and platforms is also provided, as well as some potential applications of the solution, like robust control strategies or machine learning.

scholarly journals A Passive Dynamic Approach for Flapping-Wing Micro-Aerial Vehicle Control

2010 ◽  
Author(s):  
Katie Byl
Keyword(s):  
Flapping Wing ◽  
Power Stroke ◽  
High Fidelity ◽  
Aerodynamic Forces ◽  
Dynamic Approach ◽  
Micro Aerial Vehicle ◽  
Control Approach ◽  
Couple Motion ◽  
Aerial Vehicle ◽  
And Control

This article outlines a new control approach for flapping-wing micro-aerial vehicles (MAVs), inspired both by biological systems and by the need for lightweight actuation and control solutions. In our approach, the aerodynamic forces required for agile motions are achieved indirectly, by modifying passive impedance properties that couple motion of the power stroke to the angle of attack (AoA) of the wing. This strategy is theoretically appealing because it can exploit an invariant, cyclical power stroke, for efficiency, and because an impedance-adjusting strategy should also require lower bandwidth, weight, and power than direct, intra-wingbeat control of AoA. We examine the theoretical range of control torques and forces that can be achieved using this method and conclude that it is a plausible method of control. Our results demonstrate the potential of a passive dynamic design and control approach in reducing mechanical complexity, weight and power consumption of an MAV while achieving the aerodynamic forces required for the types of high-fidelity maneuvers that drive current interest in autonomous, flapping-wing robotics.

scholarly journals Towards Bio-Inspiration, Development, and Manufacturing of a Flapping-Wing Micro Air Vehicle

Drones ◽  
2020 ◽  
Vol 4 (3) ◽  
pp. 39
Author(s):  
P. Lane ◽  
G. Throneberry ◽  
I. Fernandez ◽  
M. Hassanalian ◽  
R. Vasconcellos ◽  
...  
Keyword(s):  
Aerodynamic Force ◽  
Force Production ◽  
Flight Test ◽  
Flapping Wing ◽  
Micro Air Vehicle ◽  
Air Vehicle ◽  
Successful Design ◽  
The Stability ◽  
And Control ◽  
The Impact

Throughout the last decade, there has been an increased demand for intricate flapping-wing drones with different capabilities than larger drones. The design of flapping-wing drones is focused on endurance and stability, as these are two of the main challenges of these systems. Researchers have recently been turning towards bioinspiration as a way to enhance aerodynamic performance. In this work, the propulsion system of a flapping-wing micro air vehicle is investigated to identify the limitations and drawbacks of specific designs. Each system has a tandem wing configuration inspired by a dragonfly, with wing shapes inspired by a bumblebee. For the design of this flapping-wing, a sizing process is carried out. A number of actuation mechanisms are considered, and two different mechanisms are designed and integrated into a flapping-wing system and compared to one another. The second system is tested using a thrust stand to investigate the impact of wing configurations on aerodynamic force production and the trend of force production from varying flapping frequency. Results present the optimal wing configuration of those tested and that an angle of attack of two degrees yields the greatest force production. A tethered flight test is conducted to examine the stability and aerodynamic capabilities of the drone, and challenges of flapping-wing systems and solutions that can lead to successful flight are presented. Key challenges to the successful design of these systems are weight management, force production, and stability and control.

Towing Tank Experiments for Flapping-Wing Aerodynamics

2017 ◽  
Author(s):  
Jong-Seob Han ◽  
Jong-Wan Lee ◽  
Jae-Hung Han
Keyword(s):  
Cross Sections ◽  
Aerodynamic Force ◽  
Scale Up ◽  
Aerodynamic Characteristics ◽  
Flapping Wing ◽  
Test Results ◽  
Towing Tank ◽  
Image Velocimetry ◽  
Towing Tank Experiment ◽  
Wing Aerodynamics

This paper presents an empirical approach for flapping-wing aerodynamics using a servo-driven towing tank and a dynamically scale-up robotic manipulator. Time-varying aerodynamic force and moment were measured, and digital particle image velocimetry in multiple cross-sections were conducted. Three case studies showed that the towing tank experiment could be an effective way to investigate the aerodynamic characteristics in detail, which are difficult to be predicted by other conventional approaches. The force and moment measurements clarified that an advance ratio has significant role in governing the LEV behavior and consequent aerodynamic performance of flapping wings. Results for moving sideways showed the effects of the wing-wing and wing-body interaction, and the usefulness of the towing tank experiments for analyzing the flight dynamic characteristics. It was also shown that the towing tank experiments can be applicable to realistic wing motions; test results using the wing kinematics of a living insect in forward flight were well compatible with the trim condition of the insect.

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.

Modeling and control of a flapping wing robot

2018 ◽  
Vol 233 (1) ◽  
pp. 174-181 ◽  
Author(s):  
Abdolbaghi Bakhtiari ◽  
Shahram Ehtemadi Haghighi ◽  
Adel Maghsoudpour
Keyword(s):  
Aerodynamic Force ◽  
Leading Edge ◽  
Flapping Wing ◽  
Inversion Method ◽  
Force Model ◽  
Modeling And Control ◽  
Theoretical Predictions ◽  
Dynamics And Control ◽  
Convergence Performance ◽  
And Control

The dynamics and control of a flapping wing robot are studied in this paper which helps to develop a complete dynamic model for the robot consisting of tail effects and also enhance the path tracking control of the robot. In the first part of the paper, the aerodynamic model of the wings is presented, and an aerodynamic force model for the tail is introduced which includes the leading edge suction effects. An experiment is also carried out on a flapping wing robot in a laboratory environment to evaluate the forces on the tail and its result will be compared with the results of the model presented for the tail. In the second part, a controller is designed for the robot. This controller uses the nonlinear dynamic inversion method to solve the nonlinear equations of the control system. The experimental results of the tail forces agree well with the theoretical predictions and reveal that the tail aerodynamics are affected by leading edge suction. Also, simulation results show that the competence performance and convergence performance of the designed controller are obtained.

Sign in / Sign up

Export Citation Format

Share Document