Input-output Invertibility and Sliding Mode Control for Close Formation Flying of Multiple UAVS

Authors

Sahjendra N. Singh, University of Nevada, Las VegasFollow
Meir Pachter, Air Force Institute of Technology (AFIT/ENG)Follow
Phil Chandler, Air Force Research Laboratory (AFRL/VACA)Follow
Siva Banda, Air Force Research Laboratory (AFRL/VACA)Follow
Steve Rasmussen, Air Force Research Laboratory (AFRL/VACA)Follow
Corey Schumacher, Air Force Research Laboratory (AFRL/VACA)Follow

Document Type

Article

Publication Date

8-2000

Publication Title

International Journal of Robust and Nonlinear Control

Volume

10

First page number:

779

Last page number:

797

Abstract

This paper treats the question of invertibility of input–output maps and the design of a robust control system for formation flying of multiple unmanned aerial vehicles (UAVs). In close formation, the wing UAV motion is affected by the vortex of the adjacent lead aircraft. The forces produced by these vortices are complex functions of relative position coordinates of the UAVs. In this paper, these forces are treated as unknown functions. For trajectory tracking, invertibility of certain input–output maps in the wind axes system are examined. Interestingly, in the wind axes system, the system is not invertible, but in a simplified co-ordinate system obtained from the wind axes system for which the velocity roll is zero, inverse control of separation co-ordinates is possible. Variable structure control laws are derived for separation trajectory control of wing aircraft in the simplified wind co-ordinate system and for the flight control of the lead aircraft. Simulation results for two UAVs are presented which show precise separation trajectory control in spite of the presence of unknown vortex forces, while the lead aircraft maneuvers. Furthermore, these results confirm that when the wing aircraft is positioned properly in the vortex of the lead aircraft, there is a reduction in the required flight power.

Keywords

Control of UAVs; Feedback linearization; Formation control; Inverse control; Nonlinear system; Variable structure control

Disciplines

Aerospace Engineering | Controls and Control Theory | Electrical and Computer Engineering | Multi-Vehicle Systems and Air Traffic Control | Navigation, Guidance, Control and Dynamics | Signal Processing | Space Vehicles | Systems and Communications | Systems Engineering and Multidisciplinary Design Optimization

Language

English

Permissions

Use Find in Your Library, contact the author, or interlibrary loan to garner a copy of the item. Publisher policy does not allow archiving the final published version. If a post-print (author's peer-reviewed manuscript) is allowed and available, or publisher policy changes, the item will be deposited.

Repository Citation

Singh, S. N., Pachter, M., Chandler, P., Banda, S., Rasmussen, S., Schumacher, C. (2000). Input-output Invertibility and Sliding Mode Control for Close Formation Flying of Multiple UAVS. International Journal of Robust and Nonlinear Control, 10 779-797.