Flapping mechanisms with large stroke angles

• Main Authors: Yi-Wei Chiang, 江逸偉
• Other Authors: Lung-Jieh Yang
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/10429243663602360073

碩士 === 淡江大學 === 機械與機電工程學系碩士班 === 100 === Tamkang University MEMS group has already developed flapping wing ornithopters (MAVs) for over 9 years. The development of the 20cm-wingspan “Golden Snitch” has a flight endurance of more than 8 minutes. How to modify the flapping mechanism for the new generation of MAVs is always one of the most crucial issues. Most of the birds have their flight way mainly in gliding and loitering, and the flapping wing stroke angle is approximately 60 to 70 degrees. The hummingbirds can hover and the flapping stroke angle is 120 degrees. Bigger flapping stroke angle can do hovering better, but in the past four-bar linkage has the inevitable phase lag. The phase lag is due to the fail in mechanism symmetry and synchrony, which can cause unstable flight. The current transmission mechanism of “Golden Snitch” has the flapping wing stroke angle of 53 degrees, and the phase lag is less than 3 degrees. Improvements for the prototype of using the spring to increase the stroke angle and reduce the phase lag flapping mechanism have been demonstrated.