Flight dynamics and control of two autonomous helicopters carrying an external slung load
Abstract/Contents
- Abstract
- Cargo missions of the near future will require transportation of increasingly heavy loads to remote locations that are at distances farther, and at altitudes higher, than what can be accomplished by current helicopters. Using two helicopters to carry a single load, termed dual lift, provides heavy lift on demand and avoids the very costly design and development of a special purpose heavy lift helicopter. The dual lift benefits of increased lifting capability, increased range, and flight at higher density altitudes, are contingent on equal load distribution between the helicopters. In other words, each helicopter must lift an equal portion of the external payload. Furthermore, to maximize these benefits, the helicopters must operate close to their maximum power available, leaving little room for unequal load distribution. This research focuses on gaining a fundamental understanding of the dynamic behavior of a dual lift system and the associated flight control challenges. A detailed stability and control analysis of the dual lift system has been conducted and the unique multi-body modes and their effects on the development of an attitude control system has been quantified. With the identified control challenges as a foundation, a multi-objective parametric optimization approach has been used to design an attitude control system that meets a comprehensive set of stability and performance specifications. In addition, a guidance and control strategy that ensures equal load distribution between the helicopters has been developed. The guidance strategy computes an optimal trajectory for the system to fly using nonlinear programming and incorporates a feedback controller that commands an additive height change for the trail helicopter to account for un- modeled dynamics and disturbances. The developed concepts, models, and guidance strategies have been validated and assessed via flight test experiments on two medium-sized, autonomous RMAX helicopters (10 ft rotor diameter). This was the first time that two autonomous helicopters have been flown in the pendant configuration and with a control system that equalized the two helicopter loads.
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 | 2019; ©2019 |
| Publication date | 2019; 2019 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Author | Berrios, Marcos G |
|---|---|
| Degree supervisor | Powell, J. David, 1938- |
| Degree supervisor | Rock, Stephen M |
| Thesis advisor | Powell, J. David, 1938- |
| Thesis advisor | Rock, Stephen M |
| Thesis advisor | Pavone, Marco, 1980- |
| Degree committee member | Pavone, Marco, 1980- |
| Associated with | Stanford University, Department of Aeronautics and Astronautics. |
Subjects
| Genre | Theses |
|---|---|
| Genre | Text |
Bibliographic information
| Statement of responsibility | Marcos Gabriel Berrios. |
|---|---|
| Note | Submitted to the Department of Aeronautics and Astronautics. |
| Thesis | Thesis Ph.D. Stanford University 2019. |
| Location | electronic resource |
Access conditions
- Copyright
- © 2019 by Marcos G Berrios
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
Also listed in
Loading usage metrics...