In an attempt to realize a flapping wing micro-air vehicle with morphing wings, we report on improvements to our previousfoldable artificial hind wing.Multiple hinges, which were implemented to mimic the bending zone ...In an attempt to realize a flapping wing micro-air vehicle with morphing wings, we report on improvements to our previousfoldable artificial hind wing.Multiple hinges, which were implemented to mimic the bending zone of a beetle hind wing, weremade of small composite hinge plates and tiny aluminum rivets.The buck-tails of rivets were flared after the hinge plates wereassembled with the rivets so that the folding/unfolding motions could be completed in less time, and the straight shape of theartificial hind wing could be maintained after fabrication.Folding and unfolding actions were triggered by electrically-activatedShape Memory Alloy (SMA) wires.For wing folding, the actuation characteristics of the SMA wire actuator were modifiedthrough heat treatment.Through a series of flapping tests, we confirmed that the artificial wings did not fold back and arbitrarilyfluctuate during the flapping motion.展开更多
Emulating periodic main wing movement of a bird for generating lift and thrust remains a significant challenge in developing a robotic bird.The sequences of main wing motion are comprised of flapping,folding,bending,a...Emulating periodic main wing movement of a bird for generating lift and thrust remains a significant challenge in developing a robotic bird.The sequences of main wing motion are comprised of flapping,folding,bending,and twisting.In this paper,we concentrate on the flapping and folding motion,and design two wing mechanisms based on a 4-bar linkage structure:one is only for Flapping Motion(FM)and the other is for simultaneous Flapping and Folding Motion(FFM)during a wing stroke.We derive relationships between length and angle of links to analyze kinematic characteristics of the mechanisms and conduct an optimization to select the length parameters of links that allow maximization of the flapping angle.We run a simulation to confirm the performance of the optimized parameters by examining physical properties,and fabricate two wing mechanisms accordingly.In particular,the folding motion is achieved without using an additional actuator.Force measurements to investigate a lift profile of each mechanism and their quantitative comparison of the performance of both types confirm the benefits of the folding motion in the perspectives of wing frequency and lift.We expect that our kinematic formulation,design procedures,and comparative measurement results can help develop a wing mechanism to create a truly biomimetic robotic bird.展开更多
The influences of airfoil thickness on the aerodynamic loading distribution and the hinge moments of folding wing aircraft are presented in this work.The traditional panel method shows deficiencies in the calculation ...The influences of airfoil thickness on the aerodynamic loading distribution and the hinge moments of folding wing aircraft are presented in this work.The traditional panel method shows deficiencies in the calculation of folding wing's hinge moments.Thus, a thickness correction strategy for the aerodynamic model with CFD results is proposed, and an aeroelastic flight simulation platform is constructed based on the secondary development of ADAMS.Based on the platform,the developed aerodynamic model is verified, then the flight-folding process of the folding wing aircraft is simulated, and the influences of airfoil thickness on the results are investigated.Results show that the developed aerodynamic model can effectively describe the thickness effect of the folding wing.Airfoil thickness, which cannot be considered by the panel method, has a great influence on the hinge moments during the folding process, and the thickness correction has great significance in the calculation of folding wing's hinge moments.展开更多
This paper presents an experimental research aiming to realize an artificial hind wing that can mimic the wing unfolding motion of Allomyrina dichotoma, an insect in coleopteran order. Based on the understanding of wo...This paper presents an experimental research aiming to realize an artificial hind wing that can mimic the wing unfolding motion of Allomyrina dichotoma, an insect in coleopteran order. Based on the understanding of working principles of beetle wing folding/unfolding mechanisms, the hind wing unfolding motion is mimicked by a combination of creative ideas and state-of-art artificial muscle actuator. In this work, we devise two types of artificial wings and the successfully demonstrate that they can be unfolded by actuation of shape memory alloy wires to provide actuation force at the wing base and along the leading edge vein. The folding/unfolding mechanisms may provide an insight for portable nano/micro air vehicles with morphing wings.展开更多
基金supported by the Korea Science and Engineering Foundation Grant(National Research Laboratory Program,R0A-2007-000-200012-0)the Korea Research Foundation(KRF-006-005-J03301)partially supported by the 2009 KU Brain Pool of Konkuk University
文摘In an attempt to realize a flapping wing micro-air vehicle with morphing wings, we report on improvements to our previousfoldable artificial hind wing.Multiple hinges, which were implemented to mimic the bending zone of a beetle hind wing, weremade of small composite hinge plates and tiny aluminum rivets.The buck-tails of rivets were flared after the hinge plates wereassembled with the rivets so that the folding/unfolding motions could be completed in less time, and the straight shape of theartificial hind wing could be maintained after fabrication.Folding and unfolding actions were triggered by electrically-activatedShape Memory Alloy (SMA) wires.For wing folding, the actuation characteristics of the SMA wire actuator were modifiedthrough heat treatment.Through a series of flapping tests, we confirmed that the artificial wings did not fold back and arbitrarilyfluctuate during the flapping motion.
基金supported by the foun⁃dation of National Key Laboratory of Science and Technolo⁃gy on Aerodynamic Design and Research(No.614220121020114)the Key R&D Projects of Hunan Province(Nos.2021GK2011,2023GK2022)。
基金This research was supported by a grant to Bio-Mimetic Robot Research Center Funded by Defense Acquisition Program Administration,and by Agency for Defense Development(UD190018ID).
文摘Emulating periodic main wing movement of a bird for generating lift and thrust remains a significant challenge in developing a robotic bird.The sequences of main wing motion are comprised of flapping,folding,bending,and twisting.In this paper,we concentrate on the flapping and folding motion,and design two wing mechanisms based on a 4-bar linkage structure:one is only for Flapping Motion(FM)and the other is for simultaneous Flapping and Folding Motion(FFM)during a wing stroke.We derive relationships between length and angle of links to analyze kinematic characteristics of the mechanisms and conduct an optimization to select the length parameters of links that allow maximization of the flapping angle.We run a simulation to confirm the performance of the optimized parameters by examining physical properties,and fabricate two wing mechanisms accordingly.In particular,the folding motion is achieved without using an additional actuator.Force measurements to investigate a lift profile of each mechanism and their quantitative comparison of the performance of both types confirm the benefits of the folding motion in the perspectives of wing frequency and lift.We expect that our kinematic formulation,design procedures,and comparative measurement results can help develop a wing mechanism to create a truly biomimetic robotic bird.
基金co-supported by a Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutionsthe National Natural Science Foundation of China(No.11472133)。
文摘The influences of airfoil thickness on the aerodynamic loading distribution and the hinge moments of folding wing aircraft are presented in this work.The traditional panel method shows deficiencies in the calculation of folding wing's hinge moments.Thus, a thickness correction strategy for the aerodynamic model with CFD results is proposed, and an aeroelastic flight simulation platform is constructed based on the secondary development of ADAMS.Based on the platform,the developed aerodynamic model is verified, then the flight-folding process of the folding wing aircraft is simulated, and the influences of airfoil thickness on the results are investigated.Results show that the developed aerodynamic model can effectively describe the thickness effect of the folding wing.Airfoil thickness, which cannot be considered by the panel method, has a great influence on the hinge moments during the folding process, and the thickness correction has great significance in the calculation of folding wing's hinge moments.
基金Supported by the Korea Science and Engineering Foundation Grant (R0A-2007-000-200012-0)Korea Research Foundation (KRF-2006-005-J03301)
文摘This paper presents an experimental research aiming to realize an artificial hind wing that can mimic the wing unfolding motion of Allomyrina dichotoma, an insect in coleopteran order. Based on the understanding of working principles of beetle wing folding/unfolding mechanisms, the hind wing unfolding motion is mimicked by a combination of creative ideas and state-of-art artificial muscle actuator. In this work, we devise two types of artificial wings and the successfully demonstrate that they can be unfolded by actuation of shape memory alloy wires to provide actuation force at the wing base and along the leading edge vein. The folding/unfolding mechanisms may provide an insight for portable nano/micro air vehicles with morphing wings.
