Avian-inspired rudderless flight with morphing wings and tails
Abstract/Contents
- Abstract
- Winged aircraft typically have vertical tails and rudders for directional stability and control, but removing these vertical tails could enable flight performance improvements through weight and drag reduction. Previous approaches to rudderless flight have compromised drag, weight, or maneuverability. In contrast, birds can articulate and morph their wings and tails, continuously adjusting aerodynamic geometry for unparalleled flight performance, all with no vertical tail surface. We explore mechanisms for rudderless bird flight in two flight regimes: flapping and gliding, which are vastly unique in their aerodynamics. For flapping flight, we developed a wind tunnel study that measured the passive yaw dynamics of small ornithopters, inspired by birds that navigate 45 degree crosswinds with ease. Our results demonstrate a passive yaw sideslip suppression mechanism available to flapping wings for the first time, which can be sufficient as a flapping wing vehicle's only static directional stability mechanism for yaw stability. For gliding flight at lower angles of attack, however, birds must use a different strategy. To study how wing and tail morphing may be used for rudderless bird flight, we developed a new class of soft feathered aerial robots that underactuate feathers to generate biomimetic bird wing and tail morphing. Our experiments and analysis show how the underactuation mechanism used in these vehicles are remarkably high-bandwidth and aeroelastically stable. Through wind tunnel and flight tests, we demonstrate how birds can use finger motion to steer precisely, or wrist motion to steer coarsely in flight. We also found that without a vertical tail, many bird planforms are dynamically unstable but can use lateral tail tilt to stabilize yaw rates for stable flight. We culminate this research with a comprehensive morphing wing and tail robot composed of 52 feathers underactuated by 8 active degrees of freedom, and use it to show how birds can synergize their wing and tail morphing degrees of freedom to achieve robust flight in turbulence and aggressive maneuvers, all with inexpensive and relatively low performance actuators. We envision this work to inspire future aerial robot designs that are more stable, efficient, and maneuverable, all while remaining simple to actuate and control.
Description
| Type of resource | text |
|---|---|
| Form | electronic resource; remote; computer; online resource |
| Extent | 1 online resource. |
| Place | California |
| Place | [Stanford, California] |
| Publisher | [Stanford University] |
| Copyright date | 2020; ©2020 |
| Publication date | 2020; 2020 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Author | Chang, Eric |
|---|---|
| Degree supervisor | Cutkosky, Mark R |
| Degree supervisor | Lentink, David, 1975- |
| Thesis advisor | Cutkosky, Mark R |
| Thesis advisor | Lentink, David, 1975- |
| Thesis advisor | Follmer, Sean |
| Degree committee member | Follmer, Sean |
| Associated with | Stanford University, Department of Mechanical Engineering |
Subjects
| Genre | Theses |
|---|---|
| Genre | Text |
Bibliographic information
| Statement of responsibility | Eric Chang. |
|---|---|
| Note | Submitted to the Department of Mechanical Engineering. |
| Thesis | Thesis Ph.D. Stanford University 2020. |
| Location | electronic resource |
Access conditions
- Copyright
- © 2020 by Eric Chang
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