Application and Flight Test of Linearizing Transformations Using Measurement Feedback to the Nonlinear Control Problem

Antoniewicz, Robert F. and Duke, Eugene L. and Menon, P. K. A. (1991) Application and Flight Test of Linearizing Transformations Using Measurement Feedback to the Nonlinear Control Problem. Technical Report NASA TP-3154, Research Engineering, NASA Dryden Flight Research Center.

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Abstract

The design of nonlinear controllers has relied on the use of detailed aerodynamic and engine models that must be associated with the control law in the flight system implementation. Many of these controllers have been applied to vehicle flightpath control problems and have attempted to combine both inner- and outer-loop control functions in a single controller. In this paper, a new approach to the nonlinear trajectory control problem is presented. This approach uses linearizing transformations with measurement feedback to eliminate the need for detailed aircraft models in outer-loop control applications. By applying this approach and separating the inner-loop and outer-loop functions two things are achieved: (1) the need for incorporating detailed aerodynamic models in the controller is obviated and (2) the controller is more easily incorporated into existing aircraft flight-control systems. This paper also discusses an implementation of the controller described here. This controller is tested on a six degree-of-freedom F-15 simulation and in flight on an F-15 aircraft. Simulation data are presented which validates this approach over a large portion of the F-15 flight envelope. Proof of this concept is provided by flight-test data that closely matches simulation results. Flight-test data are also presented.

EPrint Type:	NASA Technical Publication
Keywords:	Aircraft control, Dynamic conversions, Linearizing transformations, Nonlinear control
Subjects:	(01 - 09) Aeronautics: (08) Aircraft Stability And Control Aircraft/Project: F-15
ID Code:	302
Deposited On:	28 July 2004
Additional Information:	56 pages. Robert F. Antoniewicz and Eugene L. Duke: Dryden Flight Research Facility, Edwards, California; P. K. A. Menon: Georgia Institute of Technology, Atlanta, Georgia.