Accession Number : ADA308905

Title :   Gain-Scheduled Aircraft Control Using Linear Parameter-Varying Feedback.

Descriptive Note : Master's thesis,

Corporate Author : AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH

Personal Author(s) : Breton, Martin R.

PDF Url : ADA308905

Report Date : JUN 1996

Pagination or Media Count : 218

Abstract : Systems which vary significantly over an operating envelope, such as fighter aircraft, generally cannot be controlled by a single linear time-invariant controller. As a result, gain-scheduling methods are employed to design control laws which can provide the desired performance. This thesis examines a relatively new approach to gain-scheduling, in which the varying controller is designed from the outset to guarantee robust performance, thereby avoiding the disadvantages of point designs. Specifically, the parameter-varying (LPV) aircraft model is linearized using linear fractional transformations (LFT's), and the resulting control problem is characterized as the solution to a set of four linear matrix inequalities (LMI's). The supporting theory is reviewed and two pitch-rate controllers are designed; one for the full longitudinal aircraft model, and another for the short period model. It is found that, even though the varying controllers are quite conservative, they can guarantee better robust performance over a large portion of an operating envelope when compared to time-invariant u-synthesis controllers.

Descriptors :   *FLIGHT CONTROL SYSTEMS, *AIRCRAFT MODELS, LINEAR SYSTEMS, FIGHTER AIRCRAFT, PITCH(MOTION), PARAMETERS, THEORY, RATES, THESES, TIME, VARIATIONS, SHORT RANGE(TIME), SCHEDULING, FEEDBACK, GAIN, FLIGHT ENVELOPE, CONTROL THEORY, INVARIANCE.

Subject Categories : Flight Control and Instrumentation
      Operations Research

Distribution Statement : APPROVED FOR PUBLIC RELEASE