188 research outputs found

    Can scalable design of wings for flapping wing micro air vehicle be inspired by natural flyers?

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    Lift production is constantly a great challenge for flapping wing micro air vehicles (MAVs). Designing a workable wing, therefore, plays an essential role. Dimensional analysis is an effective and valuable tool in studying the biomechanics of flyers. In this paper, geometric similarity study is firstly presented. Then, the pwโˆ’AR ratio is defined and employed in wing performance estimation before the lumped parameter is induced and utilized in wing design. Comprehensive scaling laws on relation of wing performances for natural flyers are next investigated and developed via statistical analysis before being utilized to examine the wing design. Through geometric similarity study and statistical analysis, the results show that the aspect ratio and lumped parameter are independent on mass, and the lumped parameter is inversely proportional to the aspect ratio. The lumped parameters and aspect ratio of flapping wing MAVs correspond to the range of wing performances of natural flyers. Also, the wing performances of existing flapping wing MAVs are examined and follow the scaling laws. Last, the manufactured wings of the flapping wing MAVs are summarized. Our results will, therefore, provide a simple but powerful guideline for biologists and engineers who study the morphology of natural flyers and design flapping wing MAVs

    ๊ผฌ๋ฆฌ๋‚ ๊ฐœ ์—†๋Š” ๋‚ ๊ฐฏ์ง“ ์ดˆ์†Œํ˜• ๋น„ํ–‰์ฒด์˜ ์ž์„ธ์กฐ์ ˆ

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    ํ•™์œ„๋…ผ๋ฌธ (๋ฐ•์‚ฌ) -- ์„œ์šธ๋Œ€ํ•™๊ต ๋Œ€ํ•™์› : ๊ณต๊ณผ๋Œ€ํ•™ ๊ธฐ๊ณ„ํ•ญ๊ณต๊ณตํ•™๋ถ€, 2020. 8. ๊น€ํ˜„์ง„.์ตœ๊ทผ ์ƒ์ฒด๋ชจ๋ฐฉ์— ๋Œ€ํ•œ ๊ด€์‹ฌ์ด ์ปค์ง€๋ฉด์„œ ์ƒ๋ช…์ฒด์˜ ๊ตฌ์กฐ, ์™ธํ˜•, ์›€์ง์ž„, ํ–‰๋™์„ ๋ถ„์„ํ•˜์—ฌ ๊ทธ๋“ค์˜ ์žฅ์ ์„ ๋กœ๋ด‡์— ์ ์šฉ์‹œ์ผœ ๊ธฐ์กด์˜ ๋กœ๋ด‡์ด ํ•ด๊ฒฐํ•  ์ˆ˜ ์—†๊ฑฐ๋‚˜ ํŠน๋ณ„ํ•œ ์ž„๋ฌด๋ฅผ ์ข€ ๋” ํšจ๊ณผ, ํšจ์œจ์ ์œผ๋กœ ํ•ด๊ฒฐํ•˜๋ ค๋Š” ์‹œ๋„๊ฐ€ ๋Š˜์–ด๋‚˜๊ณ  ์žˆ๋‹ค. ์ด๋Ÿฌํ•œ ์‹œ๋„๋Š” ๋ฌด์ธ๋น„ํ–‰์ฒด ๊ฐœ๋ฐœ์—๋„ ์ ์šฉ๋˜๊ณ  ์žˆ์œผ๋ฉฐ ๋‚ ๊ฐฏ์ง“ ๋น„ํ–‰์ฒด๊ฐ€ ์ด์— ํ•ด๋‹น๋œ๋‹ค. ๋‚ ๊ฐœ์ง“ ๋น„ํ–‰์ฒด๋Š” ๋‚ ๊ฐœ์˜ ๋ฐ˜๋ณต์šด๋™์„ ํ†ตํ•ด ๋ฐœ์ƒํ•˜๋Š” ํž˜์„ ํ†ตํ•ด ๋น„ํ–‰ํ•˜๋Š” ๋น„ํ–‰์ฒด๋กœ ์ผ๋ฐ˜์ ์œผ๋กœ ๊ผฌ๋ฆฌ๋‚ ๊ฐœ์˜ ์œ ๋ฌด์— ๋”ฐ๋ผ ์ƒˆ๋ฅผ ๋ชจ๋ฐฉํ•œ ๋น„ํ–‰์ฒด(๋ฏธ์ตํ˜• ๋น„ํ–‰์ฒด)์™€ ๊ณค์ถฉ์„ ๋ชจ๋ฐฉํ•œ ๋น„ํ–‰์ฒด(๋ฌด๋ฏธ์ตํ˜• ๋น„ํ–‰์ฒด)๋กœ ๊ตฌ๋ถ„ํ•  ์ˆ˜ ์žˆ๋‹ค. ๋ฌด๋ฏธ์ตํ˜• ๋น„ํ–‰์ฒด์˜ ๊ฒฝ์šฐ ์ œ์ž๋ฆฌ ๋น„ํ–‰์„ ํ•  ์ˆ˜ ์žˆ๊ณ , ํฌ๊ธฐ๊ฐ€ ์ž‘๊ณ  ๋ฌด๊ฒŒ๊ฐ€ ๊ฐ€๋ฒผ์›Œ ๊ณต๊ธฐ์ €ํ•ญ๋„ ์ค„์ผ ์ˆ˜ ์žˆ์œผ๋ฉฐ, ๋‚ ๋ ตํ•œ ๋น„ํ–‰์ด ๊ฐ€๋Šฅํ•˜๋‹ค๋Š” ์žฅ์ ์ด ์žˆ์ง€๋งŒ, ์ˆ˜๋™ ์•ˆ์ •์„ฑ์„ ํ™•๋ณดํ•˜๊ธฐ ์œ„ํ•œ ์ œ์–ด๋ฉด์ด ์ถฉ๋ถ„ํ•˜์ง€ ์•Š๊ณ  ์ถ”๋ ฅ ์ƒ์„ฑ๊ณผ ๋™์‹œ์— 3์ถ•์œผ๋กœ์˜ ์ œ์–ด ๋ชจ๋ฉ˜ํŠธ๋ฅผ ๋งŒ๋“ค ์ˆ˜ ์žˆ๋Š” ๋ณต์žกํ•œ ๋งค์ปค๋‹ˆ์ฆ˜์„ ๊ฐ€์ง€๊ณ  ์žˆ๋‹ค๋Š” ํŠน์ง•์„ ๊ฐ€์ง€๊ณ  ์žˆ๋‹ค. ๋ณธ ๋…ผ๋ฌธ์—์„œ๋Š” ์ €์ž์˜ ๋ฏธ์ตํ˜• ๋น„ํ–‰์ฒด์˜ ์—ฐ๊ตฌ๊ฐœ๋ฐœ ์‚ฌ๋ก€๋ฅผ ํ† ๋Œ€๋กœ ์ž์œจ ๋น„ํ–‰์„ ํ•  ์ˆ˜ ์žˆ๋Š” ๋ฌด๋ฏธ์ตํ˜• ๋น„ํ–‰์ฒด๋ฅผ ๊ฐœ๋ฐœํ•˜๊ธฐ ์œ„ํ•œ ์š”์†Œ๊ธฐ์ˆ ๋“ค๊ณผ ์ดˆ๊ธฐ ๋น„ํ–‰์ฒด ๊ฐœ๋ฐœ์„ ๋ชฉํ‘œ๋กœ ํ•œ๋‹ค. ํ•ด๋‹น ๋ชฉํ‘œ๋ฅผ ๋‹ฌ์„ฑํ•˜๊ธฐ ์œ„ํ•ด ์ €์ž๋Š” ์‹œ์ค‘์—์„œ ํŒ๋งค๋˜๊ณ  ์žˆ๋Š” RC์žฅ๋‚œ๊ฐ์„ ํ™œ์šฉํ•ด 30 gram ์ดํ•˜์˜ ๋ฌด๊ฒŒ๋ฅผ ๊ฐ€์ง€๊ณ  30cm3 ์ด๋‚ด์˜ ํฌ๊ธฐ๋ฅผ ๊ฐ€์ง€๋Š” ๋ฌด๋ฏธ์ตํ˜• ๋‚ ๊ฐฏ์ง“ ๋น„ํ–‰์ฒด๋ฅผ ๊ฐœ๋ฐœ์„ ์ง„ํ–‰ํ•˜์˜€๋‹ค. ๋น„ํ–‰์ฒด ๋‚ด๋ถ€์—๋Š” ๊ตฌ๋™๊ธฐ๋กœ DC ๋ชจํ„ฐ์™€ ์„œ๋ณด๋ชจํ„ฐ๊ฐ€ ์กด์žฌํ•˜๋ฉฐ, DC ๋ชจํ„ฐ๋Š” ๋‚ ๊ฐฏ์ง“์„ ์ผ์œผํ‚ค๋Š” ๊ธฐ์–ด ๋ฐ•์Šค๋ฅผ ์ž‘๋™์‹œ์ผœ ๋น„ํ–‰์ฒด์˜ ๋ฌด๊ฒŒ๋ฅผ ์ง€ํƒฑํ•˜๊ธฐ ์œ„ํ•œ thrust๋ฅผ ์ƒ์„ฑํ•˜๋ฉฐ roll์ถ• ๋ฐฉํ–ฅ์œผ๋กœ์˜ moment ์ƒ์„ฑ์— ๊ด€์—ฌํ•˜๋ฉฐ, ์„œ๋ณด๋ชจํ„ฐ๋Š” ๋‚ ๊ฐฏ์ง“์—์„œ ๋ฐœ์ƒํ•˜๋Š” ์ขŒ์šฐ thrust์˜ ๋ฐฉํ–ฅ์„ ์กฐ์ ˆํ•˜์—ฌ pitch ์™€ yaw ์ถ•์œผ๋กœ์˜ ๋ชจ๋ฉ˜ํŠธ๋ฅผ ์ƒ์„ฑํ•˜๋Š”๋ฐ ์‚ฌ์šฉ๋œ๋‹ค. ๋น„ํ–‰์ฒด ๋‚ด๋ถ€์—๋Š” ์•„๋‘์ด๋…ธ ๋ณด๋“œ ๊ธฐ๋ฐ˜์˜ ๋งˆ์ดํฌ๋กœํ”„๋กœ์„ธ์„œ๊ฐ€ ํƒ‘์žฌ๋˜์–ด ์žˆ์–ด ๋น„ํ–‰์ฒด๋ฅผ ์ œ์–ดํ•˜๊ธฐ ์œ„ํ•œ ์‹ ํ˜ธ๋ฅผ ์ƒ์„ฑํ•  ์ˆ˜ ์žˆ์œผ๋ฉฐ ๋ธ”๋ฃจํˆฌ์Šค ํ†ต์‹  ๋ชจ๋“ˆ์„ ๊ฐ€์ง€๊ณ  ์žˆ๊ธฐ ๋•Œ๋ฌธ์— ์™ธ๋ถ€์™€ ํ†ต์‹  ์—ญ์‹œ ๊ฐ€๋Šฅํ•˜๋‹ค. ๋น„ํ–‰์ฒด์˜ ์ž์„ธ๋ฅผ ์ œ์–ดํ•˜๊ธฐ ์œ„ํ•ด์„œ๋Š” ๊ตฌ๋™๊ธฐ์˜ ์ƒํ˜ธ์ž‘์šฉ์œผ๋กœ ์ธํ•ด ๋ฐœ์ƒํ•˜๋Š” ํž˜์˜ ๋ฌผ๋ฆฌ๋Ÿ‰์„ ํŒŒ์•…ํ•˜๋Š” ๊ฒƒ์ด ์ค‘์š”ํ•˜๋‹ค. ์ด๋ฅผ ์œ„ํ•ด ๋‚ ๊ฐฏ์ง“ ๋ฉ”์ปค๋‹ˆ์ฆ˜์—์„œ ๋ฐœ์ƒํ•˜๋Š” ํž˜์„ ์ธก์ •ํ•˜๋Š” ์‹คํ—˜์„ ์ˆ˜ํ–‰ํ•˜์˜€๋‹ค. ์ธก์ •์‹คํ—˜์„ ํ†ตํ•ด DC๋ชจํ„ฐ ์ž…๋ ฅ ๋Œ€๋น„ thrust ํฌ๊ธฐ, ์„œ๋ณด๋ชจํ„ฐ command ์ž…๋ ฅ ๋Œ€๋น„ moment ํฌ๊ธฐ ๋“ฑ์˜ ๊ด€๊ณ„๋ฅผ ํŒŒ์•…ํ•˜์˜€๋‹ค. ๋˜ํ•œ ๋‚ ๊ฐฏ์ง“ ๋น„ํ–‰์ฒด๋ฅผ ๊ณต์ค‘์— ๋„์šธ ์ˆ˜ ์žˆ๋Š” ์ถฉ๋ถ„ํ•œ ํฌ๊ธฐ์˜ thrust๋ฅผ ๋ฐœ์ƒํ•˜๋Š” ๊ฒƒ์„ ํ™•์ธํ•˜์˜€์œผ๋ฉฐ ์ž์„ธ ์ œ์–ด๋ฅผ ์œ„ํ•œ ๋ชจ๋ฉ˜ํŠธ ์ƒ์„ฑ ์—ญ์‹œ ๊ฐ€๋Šฅํ•˜๋‹ค๋Š” ๊ฒƒ์„ ํ™•์ธํ•˜์˜€๋‹ค. ๋น„ํ–‰์ฒด์˜ ์ž์„ธ๋ฅผ ์ œ์–ดํ•˜๊ธฐ ์œ„ํ•ด์„œ๋Š” 3์ถ• ๋ฐฉํ–ฅ์œผ๋กœ์˜ ์šด๋™๋ฐฉ์ •์‹์„ ์œ ๋„ํ•˜๋Š” ๊ฒƒ์ด ํ•„์š”ํ•˜๋‹ค. ์ด๋ฅผ ์œ„ํ•ด roll, pitch, yaw ์ถ• ๋ฐฉํ–ฅ์œผ๋กœ ๋น„ํ–‰์ฒด์—์„œ ๋ฐœ์ƒํ•˜๋Š” ํž˜๊ณผ ํšŒ์ „ ์šด๋™๊ณผ ๊ด€๋ จํ•œ ์šด๋™๋ฐฉ์ •์‹์„ ์œ ๋„ํ–ˆ์œผ๋ฉฐ ์ด๋ฅผ ํ†ตํ•ด ๋น„ํ–‰์ฒด์˜ ์ž์„ธ๋ฅผ ์•ˆ์ •ํ™”์‹œํ‚ฌ ์ˆ˜ ์žˆ๋„๋ก ํ•˜๋Š” PID ์ œ์–ด๊ธฐ ํ˜•ํƒœ์˜ ์ œ์–ด๊ธฐ๋ฅผ ์„ค๊ณ„ํ•˜์˜€๋‹ค. ๋ฟ๋งŒ ์•„๋‹ˆ๋ผ, ๋น„ํ–‰์ฒด์˜ ๊ถค์ ์ถ”์ข… ์ œ์–ด๋ฅผ ์œ„ํ•ด ๋‚ด๋ถ€์˜ ์ž์„ธ ์ œ์–ด๊ธฐ์— ๋น„ํ–‰์ฒด์˜ ์œ„์น˜๋ฅผ ํ† ๋Œ€๋กœ ๊ณ„์‚ฐ๋˜๋Š” ์ถ”๊ฐ€์ ์ธ ์™ธ๋ถ€ ์ œ์–ด๊ธฐ๋ฅผ ์„ค๊ณ„ํ•˜์—ฌ ์ด์ค‘๋ฃจํ”„ ์ œ์–ด๊ธฐ ํ˜•ํƒœ๋ฅผ ์ ์šฉ์‹œ์ผœ ์‹œ๋ฎฌ๋ ˆ์ด์…˜์„ ํ†ตํ•ด ๋น„ํ–‰์ฒด์˜ ์ž์„ธ ์ œ์–ด์™€ ๊ถค์  ์ถ”์ข… ์ œ์–ด๊ฐ€ ์ด๋ฃจ์–ด์ง์„ ํ™•์ธํ•˜์˜€๋‹ค. ๊ฐœ๋ฐœํ•œ ๋น„ํ–‰์ฒด์™€ ์•ž์„œ ์„ค๊ณ„ํ•œ ์ œ์–ด๊ธฐ๊ฐ€ ์‚ฌ์šฉ์ž์˜ ์˜๋„์— ๋งž๋Š” ์„ฑ๋Šฅ์„ ๋‚ด๋Š”์ง€ ํ™•์ธํ•˜๊ธฐ ์œ„ํ•ด ์ž์ด๋กœ ์‹คํ—˜์žฅ์น˜๋ฅผ ์ œ์ž‘ํ•˜์—ฌ ์ž์„ธ ์ œ์–ด ์‹คํ—˜์„ ์ˆ˜ํ–‰ํ•˜์˜€๋‹ค. ํ•ด๋‹น ์‹คํ—˜์žฅ์น˜๋Š” roll, pitch, yaw ์ถ•์œผ๋กœ ํšŒ์ „์ด ๊ฐ€๋Šฅํ•˜๋„๋ก ์ œ์ž‘ํ•˜์˜€์œผ๋ฉฐ ์‹คํ—˜์žฅ์น˜ ์ž์ฒด์˜ ๋ฌด๊ฒŒ๋ฅผ ์ค„์ด๊ธฐ ์œ„ํ•ด MDF ์†Œ์žฌ๋ฅผ ์‚ฌ์šฉํ•˜์—ฌ ๊ตฌ์กฐ๋ฌผ๋ฅผ ๋งŒ๋“ค์—ˆ๋‹ค. roll, pitch, yaw 3์ถ•์ด ๊ฐ๊ฐ ๋…๋ฆฝ์ ์œผ๋กœ ์ œ์–ดํ•˜๋Š” ๊ฒƒ๊ณผ 3์ถ•์„ ๋™์‹œ์— ์ œ์–ดํ•˜๋Š” 2๊ฐ€์ง€ ์ƒํ™ฉ์„ ๊ณ ๋ คํ•˜์˜€์œผ๋ฉฐ ์•ž์„œ ์„ค๊ณ„ํ•œ ์ œ์–ด๊ธฐ๊ฐ€ ํ•ด๋‹น ์‹คํ—˜ ์žฅ์น˜ ๋‚ด๋ถ€์—์„œ ์‚ฌ์šฉ์ž์˜ ์˜๋„์— ๋งž๊ฒŒ ์ œ์–ด ์„ฑ๋Šฅ์„ ๋ณด์ด๋Š”์ง€ ํ™•์ธํ•  ์ˆ˜ ์žˆ์—ˆ๋‹ค. ๊ถค์  ์ถ”์ข…์ œ์–ด๋ฅผ ์œ„ํ•ด์„œ๋Š” 2๊ฐ€์ง€ ๋น„ํ–‰ ์ƒํ™ฉ์„ ์„ค์ •ํ•˜์˜€๋‹ค. ์ฒซ ๋ฒˆ์งธ ๊ฒฝ์šฐ, ์ฒœ์žฅ๊ณผ ๋น„ํ–‰์ฒด ์ƒ๋‹จ๋ถ€์— ์‹ค์„ ์—ฐ๊ฒฐํ•˜์—ฌ 2D ํ‰๋ฉด์ƒ์—์„œ ๋น„ํ–‰์ฒด๊ฐ€ ์ฃผ์›Œ์ง„ ๊ถค์ ์— ๋”ฐ๋ผ ์›€์ง์ด๋Š”์ง€, ๋‘ ๋ฒˆ์งธ ๊ฒฝ์šฐ, ๋น„ํ–‰์ฒด ์ƒ๋‹จ๋ถ€์— ํ—ฌ๋ฅจ์ด ์ฃผ์ž…๋œ ํ’์„ ์„ ์—ฐ๊ฒฐ์‹œ์ผœ 3D ๊ณต๊ฐ„์ƒ์—์„œ ์ฃผ์›Œ์ง„ ๊ถค์ ์„ ๋”ฐ๋ผ ์ถ”์ข… ๋น„ํ–‰ํ•˜๋Š”์ง€๋ฅผ ํ™•์ธํ•  ์ˆ˜ ์žˆ๋Š” ์ƒํ™ฉ์ด๋‹ค. ๋‘ ๊ฐ€์ง€ ์ƒํ™ฉ์—์„œ ๋ชจ๋‘ ๋‹ค์–‘ํ•œ ํ˜•ํƒœ์˜ ๊ถค์ ์„ ๋น„ํ–‰์ฒด๊ฐ€ ์ž˜ ์ถ”์ข…ํ•˜๋Š”์ง€๋ฅผ ํ™•์ธํ•  ์ˆ˜ ์žˆ์—ˆ๋‹ค. ๋์œผ๋กœ, ์™ธ๋ถ€ ์žฅ์น˜(์‹ค, ํ’์„ )๋ฅผ ์ œ๊ฑฐํ•˜์—ฌ ๊ณต์ค‘์—์„œ ๋น„ํ–‰์ฒด๊ฐ€ ์ œ์ž๋ฆฌ ๋น„ํ–‰์„ ํ•  ์ˆ˜ ์žˆ๋Š”์ง€๋ฅผ ๊ฒ€์ฆํ•˜๋Š” ์‹คํ—˜์„ ์ง„ํ–‰ํ•˜์˜€์œผ๋ฉฐ, 15์ดˆ๊ฐ€๋Ÿ‰ 1m3 ๊ณต๊ฐ„ ๋‚ด์—์„œ ์ œ์ž๋ฆฌ ๋น„ํ–‰์ด ์ด๋ฃจ์–ด์ง€๋Š” ๊ฒƒ์„ ํ™•์ธํ•˜์˜€๋‹ค.Flapping wing micro air vehicles (FWMAVs) that generate thrust and lift by flapping their wings are regarded as promising flight vehicles because of their advantages in terms of similar appearance and maneuverability to natural creatures. Reducing weight and air resistance, insect-inspired tailless FWMAVs are an attractive aerial vehicle rather than bird-inspired FWMAVs. However, they are challenging platforms to achieve autonomous flight because they have insufficient control surfaces to secure passive stability and a complicated wing mechanism for generating three-axis control moments simultaneously. In this thesis, as preliminary autonomous flight research, I present the study of an attitude regulation and trajectory tracking control of a tailless FWMAV developed. For these tasks, I develop my platform, which includes two DC motors for generating thrust to support its weight and servo motors for generating three-axis control moments to regulate its flight attitude. First, I conduct the force and moment measurement experiment to confirm the magnitude and direction of the lift and moment generated from the wing mechanism. From the measurement test, it is confirmed that the wing mechanism generates enough thrust to float the vehicle and control moments for attitude regulation. Through the dynamic equations in the three-axis direction of the vehicle, a controller for maintaining a stable attitude of the vehicle can be designed. To this end, a dynamic equation related to the rotational motion in the roll, pitch, and yaw axes is derived. Based on the derived dynamic equations, we design a proportional-integral-differential controller (PID) type controller to compensate for the attitude of the vehicle. Besides, we use a multi-loop control structure (inner-loop: attitude control, outer-loop: position control) to track various trajectories. Simulation results show that the designed controller is effective in regulating the platforms attitude and tracking a trajectory. To check whether the developed vehicle and the designed controller are operating effectively to regulate its attitude, I design a lightweight gyroscope apparatus using medium-density-fiberboard (MDF) material. The rig is capable of freely rotating in the roll, pitch, and yaw axes. I consider two situations in which each axis is controlled independently, and all axes are controlled simultaneously. In both cases, attitude regulation is properly performed. Two flight situations are considered for the trajectory tracking experiment. In the first case, a string connects between the ceiling and the top of the platform. In the second case, the helium-filled balloon is connected to the top of the vehicle. In both cases, the platform tracks various types of trajectories well in error by less than 10 cm. Finally, an experiment is conducted to check whether the tailless FWMAV could fly autonomously in place by removing external devices (string, balloon), and the tailless FWMAV flies within 1 m^3 space for about 15 seconds1.Introduction 1 1.1 Background & Motivation 1 1.2 Literature review 3 1.3 Thesis contribution 7 1.4 Thesis outline 8 2.Design of tailless FWMAV 13 2.1 Platform appearance 13 2.2 Flight control system 17 2.3 Principle of actuator mechanism 18 3.Force measurement experiment 28 3.1 Measurement setup 28 3.2 Measurement results 30 4.Dynamics & Controller design 37 4.1 Preliminary 37 4.2 Dynamics & Attitude control 39 4.2.1 Roll direction 41 4.2.2 Pitch direction 43 4.2.3 Yaw direction 45 4.2.4 PID control 47 4.3 Trajectory tracking control 48 5.Attitude regulation experiments 50 5.1 Design of gyroscope testbed 50 5.2 Experimental environment 52 5.3 Roll axis free 53 5.3.1 Simulation 54 5.3.2 Experiment 55 5.4 Pitch axis free 56 5.4.1 Simulation 57 5.4.2 Experiment 58 5.5 Yaw axis free 59 5.5.1 Simulation 59 5.5.2 Experiment 60 5.6 All axes free 60 5.6.1 Simulation 60 5.6.2 Experiment 61 5.7 Design of universal joint testbed & Experiment 64 6.Trajectory tracking 68 6.1 Simulation 68 6.2 Preliminary 69 6.3 Experiment: Tied-to-the-ceiling 70 6.4 Experiment: Hung-to-a-balloon 71 6.5 Summary 72 6.6 Hovering flight 73 7.Conclusion 83 A Appendix: Wing gearbox 85 A.1 4-bar linkage structure 85 B Appendix: Disturbance observer (DOB) 87 B.1 DOB controller 87 B.2 Simulation 89 B.2.1 Step input 89 B.2.2 Sinusoid input 91 B.3 Experiment 92 References 95Docto

    Multi-modal locomotion:from animal to application

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    Flight Mechanics and Control of Escape Manoeuvres in Hummingbirds. I. Flight Kinematics

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    Hummingbirds are natureโ€™s masters of aerobatic manoeuvres. Previous research shows that hummingbirds and insects converged evolutionarily upon similar aerodynamic mechanisms and kinematics in hovering. Herein, we use three-dimensional kinematic data to begin to test for similar convergence of kinematics used for escape flight and to explore the effects of body size upon manoeuvring. We studied four hummingbird species in North America including two large species (magnificent hummingbird, Eugenes fulgens, 7.8 g, and blue-throated hummingbird, Lampornis clemenciae, 8.0 g) and two smaller species (broad-billed hummingbird, Cynanthus latirostris, 3.4 g, and black-chinned hummingbirds Archilochus alexandri, 3.1 g). Starting from a steady hover, hummingbirds consistently manoeuvred away from perceived threats using a drastic escape response that featured body pitch and roll rotations coupled with a large linear acceleration. Hummingbirds changed their flapping frequency and wing trajectory in all three degrees of freedom on a stroke-by-stroke basis, likely causing rapid and significant alteration of the magnitude and direction of aerodynamic forces. Thus it appears that the flight control of hummingbirds does not obey the โ€˜helicopter modelโ€™ that is valid for similar escape manoeuvres in fruit flies. Except for broad-billed hummingbirds, the hummingbirds had faster reaction times than those reported for visual feedback control in insects. The two larger hummingbird species performed pitch rotations and global-yaw turns with considerably larger magnitude than the smaller species, but roll rates and cumulative roll angles were similar among the four species

    From Rousettus aegyptiacus (bat) Landing to Robotic Landing: Regulation of CG-CP Distance Using a Nonlinear Closed-Loop Feedback

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    Bats are unique in that they can achieve unrivaled agile maneuvers due to their functionally versatile wing conformations. Among these maneuvers, roosting (landing) has captured attentions because bats perform this acrobatic maneuver with a great composure. This work attempts to reconstruct bat landing maneuvers with a Micro Aerial Vehicle (MAV) called Allice. Allice is capable of adjusting the position of its Center of Gravity (CG) with respect to the Center of Pressure (CP) using a nonlinear closed-loop feedback. This nonlinear control law, which is based on the method of input-output feedback linearization, enables attitude regulations through variations in CG-CP distance. To design the model-based nonlinear controller, the Newton-Euler dynamic model of the robot is considered, in which the aerodynamic coefficients of lift and drag are obtained experimentally. The performance of the proposed control architecture is validated by conducting several experiments

    Dynamics of Micro-Air-Vehicle with Flapping Wings

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    Small (approximately 6 inch long, or hand-held) reconnaissance micro air vehicles (MAVs) will fly inside buildings, and require hover for observation, and agility at low speeds to move in confined spaces. For this flight envelope insect-like flapping wings seem to be an optimal mode of flying. Investigation of the aerodynamics of flapping wing MAVs is very challenging. The problem involves complex unsteady, viscous flow (mainly laminar), with the moving wing generating vortices and interacting with them. At this early stage of research only a preliminary insight into the nature of the little known aerodynamics of MAVs has been obtained. This paper describes computational models for simulation of the controlled motion of a microelectromechanical flying insect โ€“ entomopter. The design of software simulation for entomopter flight (SSEF) is presented. In particular, we will estimate the flight control algorithms and performance for a Micromechanical Flying Insect (MFI), a 80โ€“100 mm (wingtip-to-wingtip) device capable of sustained autonomous flight. The SSEF is an end-to-end tool composed of several modular blocks which model the wing aerodynamics and dynamics, the body dynamics, and in the future, the environment perception, control algorithms, the actuators dynamics, and the visual and inertial sensors. We present the current state of the art of its implementation, and preliminary results.

    Neurobiologically Inspired Control of Engineered Flapping Flight

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    This article presents a new control approach for engineered flapping flight with many interacting degrees of freedom. This paper explores the applications of neurobiologically inspired control systems in the form of Central Pattern Generators (CPG) to generate wing trajectories for potential flapping flight MAVs. We present a rigorous mathematical and control theoretic framework to design complex three dimensional motions of flapping wings. Most flapping flight demonstrators are mechanically limited in generating the wing trajectories. Because CPGs lend themselves to more biological examples of flight, a novel robotic model has been developed to emulate the flight of bats. This model has shoulder and leg joints totaling 10 degrees of freedom for control of wing properties. Results of wind tunnel experiments and numerical simulation of CPG-based flight control validate the effectiveness of the proposed neurobiologically inspired control approach
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