綠繡眼飛行模式分析與仿鳥拍撲機構之設計

Analysis of the Flight in Japanese White-eye and Design of a Bird-Mimicking Mechanical Flapper

黃佩儀(Pei-Yi Huang)

指導教授 ： 楊鏡堂

國立臺灣大學/工學院/機械工程學研究所/碩士(2015年)

https://doi.org/10.6342/NTU.2015.10285

摘要

本文研究綠繡眼的前飛飛行機制，並且分析前飛與爬升兩種飛行模式的差異，最後依據模式設計仿鳥拍撲機構，以了解五個運動參數對飛行特性的影響。鳥類一直是飛行的佼佼者，但鳥類多關節的翅膀構造使得拍撲飛行變得複雜，其拍撲飛行主要包含有拍撲、扭轉與折曲三種動作，文獻已證實折曲能夠有助於鳥類的飛行，章聿珩(2010)則證實相較於單純的拍撲模式，加入翼扭轉的動作對於綠繡眼的爬升飛行有效提高7~21 %之升力，然而鳥的拍撲飛行包含更多的自由度，亟需深入研究，本文可分成三個部分。
第一個部分利用動作分析與流場分析實驗探討前飛模式的飛行機制。動作分析利用兩台同步高速攝影機拍攝綠繡眼前飛的飛行動作，藉著紀錄特徵點得到特徵點移動軌跡與速度變化，將綠繡眼的前飛動作分成拋翼、下拍、上拍三個階段，並且將各關節的運動參數歸納成拍撲、扭轉、折曲、肩關節的掃略與肘關節的掃略五種參數。流場分析則使用粒子影像測速儀實驗紀錄綠繡眼前飛時的流場，觀察到在拋翼階段射流方向改變，代表在此階段有推力的產生，並藉著渦漩環理論估算綠繡眼前飛的推進力，實驗結果估算整個週期的推進力大約是體重的21.6 %。
第二部份將前飛的實驗結果與章聿珩(2010)所做的爬升飛行比較，觀察到兩種飛行模式在拍撲角、扭轉角與折曲角上的差異是影響飛行的重要因素，其中前飛模式的拍撲角振幅大於爬升模式將近70°，而扭轉角介於5°~20°之間，小於爬升模式下的35°~60°，而爬升模式在下拍期間即開始有折曲翅膀的動作，這樣的動作方式使得綠繡眼在短時間內產生相當大的推進力，此外在流場分析中可觀察到爬升模式在下拍時會形成翼前緣渦漩，產生類似昆蟲延遲失速的效果。為了進一步了解運動參數對飛行模式的影響，第三個部分初步設計與製作仿鳥拍撲機構，設計上利用四個伺服馬達實現拍撲角、扭轉角、折曲角和肘關節的掃略角四個參數，未來將進行粒子影像測速儀實驗，期望將運動參數對飛行特性的影響融入仿生載具之設計。

關鍵字

綠繡眼 ； 拍撲飛行 ； 前飛模式 ； 翼前緣渦漩 ； 渦漩環理論

並列摘要

This study investigates the forward flight of Japanese white-eye and compare the result with the ascending flight. Analyzing the differences of the two flight modes. And briefly design a bird-mimicking mechanical flapper in order to understand how the kinematic parameters affect the flight. Without saying, bird is good at flying. Compare to other animal flyers, the multiple joints of birds make the motions of flight become very complicated. The flight motions of birds are included flapping, twisting, and folding. Some studies has clarified that folding is beneficial for the flight. Chang (2010) proved that flapping motion accompanying twisting motion would increase by 7 to 21% of the lift compare to pure flapping motion. However, the bird flight includes multiple degrees of freedom, and need to be deeply investigated. And this study is divided into three parts.
At first part, I recorded the forward flight of Japanese white-eye by high speed cameras, and found the locomotor trajectory, velocity of characteristic points. And arranging the locomotor trajectory into five kinematic parameters──flapping angle, folding angle, twisting angle, sweeping angle and wing tip sweeping angle. According to these experimental data, the forward flight can be divided into three stage──downstroke, upstroke and fling. Besides, the flow field of the forward flight was visualized by particle image velocimetry (PIV). The jet was observed that changed the direction in the stage of fling, meaning that there was a thrust produced. And the force generated during the flight was also calculated by using vortex ring model and was only 21.6 % of the bird weight.
For the second part, I investigated the differences between the forward flight and the ascending flight (Chang, 2010). Finding out that flapping angle, folding angle and twisting angle are the main parameters to influence the flapping flight. The amplitude of the flapping angle of the forward flight is greater than the flapping angle of the ascending flight for 70 °. And twisting angle is between 5°~20° which is less than the the flapping angle of the ascending flight. In the ascending flight, the wings will fold during the period of downstroke. This kind of motions of the ascending flight let bird to produce a larger force than the forward flight in a short period. And the leading edge vortex was observed in the flow field of the ascending flight which is beneficial to delay stall. To clearly investigate how kinematic parameters impact flapping flight. At third part, a mechanical flapper mimicking bird wing was briefly designed and fabricated. There are four motors to achieve flapping, folding, twisting and wing tip sweeping motions in the mechanical flapper. Hoping this study can be applied to the design of biomimetic flapping aerial vehicles.

並列關鍵字

Japanese white-eye ； flapping flight ； forward flight ； leading edge vortex ； vortex ring model

參考文獻

Alexander, D. E. (2004). Nature's flyers: birds, insects, and the biomechanics of flight: JHU Press, London.

Azuma, A. (1992). Biokinetics of flying and swimming: Springer Verlag, Tokyo.

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Chang, Y. H., Ting, S. C., Su, J. Y., Soong, C. Y., Yang, J. T. (2013). Ventral-clap modes of hovering passerines. Physical Review E, 87(2), 022707.

Dickinson, M. H. (1996). Unsteady mechanisms of force generation in aquatic and aerial locomotion. American Zoologist, Vol. 36, No 6, 537-554.