Anti-Windup Control for an Air-Breathing Hypersonic Vehicle Model

Abstract

The public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden, to Department of Defense, Washington Headquarters Services, Directorate for Information SPONSORING/MONITORING AGENCY REPORT NUMBER(S)AFRL-VA-WP-TP-2006-303 DISTRIBUTION/AVAILABILITY STATEMENTApproved for public release; distribution is unlimited. SUPPLEMENTARY NOTESConference paper preprint to be presented at the 2006 AIAA Guidance, Navigation, and Control Conference, 24 Aug 06, Keystone, CO. This report contains color. This work has been submitted to AIAA for publication in the 2006 AIAA Guidance, Navigation, and Control Conference proceedings. One or more of the authors is a U.S. Government employee working within the scope of their position; therefore, the U.S. Government is joint owner of the work. If published, AIAA, Kevin P. Groves, Andrea Serrani, and/or Stephen Yurkovich may assert copyright. If so, the Government has the right to copy, distribute, and use the work. Any other form of use is subject to copyright restrictions. ABSTRACTAn anti-windup controller modification is implemented in control system design for a model of the longitudinal dynamics of an air-breathing hypersonic vehicle. Anti-windup control allows the input constraints to be considered explicitly in the design of linear controllers to track a reference trajectory for the vehicle velocity, altitude, and angle of attack. The presence of antiwindup alleviates the need of keeping large penalties on the magnitude of the control input to avoid the occurrence of saturation. This, in turn, allows tighter tuning of the controller gains to obtain faster and more accurate trajectory tracking. The paper employs recent developments in anti-windup design to deal with the presence of exponentially unstable dynamics, which are typically encountered in air-breathing vehicle models. Simulation results on a fully nonlinear model are presented to validate the controller design. An anti-windup controller modification is implemented in control system design for a model of the longitudinal dynamics of an air-breathing hypersonic vehicle. Anti-windup control allows the input constraints to be considered explicitly in the design of linear controllers to track a reference trajectory for the vehicle velocity, altitude, and angle of attack. The presence of anti-windup alleviates the need of keeping large penalties on the magnitude of the control input to avoid the occurrence of saturation. This, in turn, allows tighter tuning of the controller gains to obtain faster and more accurate trajectory tracking. The paper employs recent developments in anti-windup design to deal with the presence of expone...

Control-Relevant Modeling, Analysis, and Design for Scramjet-Powered Hypersonic Vehicles

“…22,43 It should be noted, however, that these limits were never reached in our studies 41 . Within this paper, we consider a pull up maneuver that does not result in elevator saturation.…”

Elevator Sizing, Placement, and Control-Relevant Tradeoffs for Hypersonic Vehicles

“…FPA is controlled via the elevator/canard combination 38 . Because these dynamics are inherently unstable, elevator saturation can result in instability 45 . Classical anti-windup methods may be inadequate to address the open loop unstable vehicle.…”

“…Classical anti-windup methods may be inadequate to address the open loop unstable vehicle. The constraint enforcement method within 45,47 and generalized predictive control 48 have been used to address such issues. This paper examines several methods to prevent instability due to elevator saturation.…”

“…Papers addressing nonlinear control issues include: control via classic inner-outer loop architecture 43 , nonlinear robust/adaptive control 34 , robust linear output feedback 40 , control-oriented modeling 18 , linear parameter-varying control of flexible dynamics 44 , saturation prevention 21,45,46 , and thermal choking prevention 28,46 .…”

“…Elevator constraints such as saturation can result in performance degradation, and possibly instability. 45 Anti-windup and error governor methodologies may used to maintain stability at the cost of performance. In general it is desirable to design control surfaces such that saturation does not occur for standard maneuvers.…”