A viable multivariable adaptive controller with application to autonomous helicopters

Autonomous helicopters carry out missions in inaccessible hazardous environments. Their performance capability in speed, maneuverability and trajectory tracking must be comparable, if not superior, to manned vehicles. Control laws that meet desired performance specifications are difficult to design because of the uncertain, fully-coupled nonlinear dynamics of autonomous helicopters. Uncertainties in helicopter parameters not only change the dynamics of the system but the trim inputs themselves. Many of the current control designs assume low speeds and neglect aerodynamics as well as uncertainties in system parameters. As a result, these linear and nonlinear controllers are adequate at best at hover, and therefore not viable in real plants, as the unknown trim conditions and dynamics result in severe performance degradation even at moderate speeds. For an autonomous vehicle control system to be viable, it must accommodate uncertainties in the trim conditions on-line, the effect of the aerodynamics, and parametric uncertainties, for various realistic maneuvers beyond hover. This thesis presents a viable multivariable adaptive control design methodology that is applicable to the needs of uncertain plants and high bandwidth requirements. Control in the cases where the full and partial state variables are available for measurement are considered. A systematic control design procedure that fully accommodates the aerodynamics of the autonomous vehicle is developed. The principal features of the proposed controller are the following: The multivariable adaptive controller accommodates both parametric uncertainties and unknown trim conditions through on-line adjustment of appropriate control parameters.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Mechanical Engineering.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2001

Author dc:creator

• Krupadanam, Ashish Samuel, 1974-

Advisor dc:contributor.advisor

• Anuradha M. Annaswamy.

• Mechanical Engineering.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/67169

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/67169