STUDY ON GAIN-SCHEDULING PROBLEM IN FLIGHT CONTROL

Gain-scheduling has got its wide applications in modern flight control, in which control gains are scheduled with variables such as dynamic pressure and Mach number, to meet dynamic response requirements in different flight conditions. Classical gain-scheduling approaches may result in some problems, which can not guarantee global robustness and stability in transitions of different flight conditions. Gain-scheduling problem is systematically investigated from robustness point of view in the paper. Detailed procedures for gain-scheduled controller to achieve both robustness and stability performance are given and applied to a typical flight control system. For switching stability problems of different flight conditions in flight control systems, a new approach is proposed, in which different flight conditions are reduced into a parameter varying plant using interpolation firstly, and then parameter-varying controller design goes next. Though interpolation errors may exist, the robust parameter varying controller design can compensate for those uncertainties and errors, and finally achieve good performance of robustness and switching stability during transitions. Illustrative simulation at last shows satisfactory results.

STUDY ON GAIN-SCHEDULING PROBLEM IN FLIGHT CONTROL

Gain-scheduling has gotits w ide applications in m odern flightcontrol, in w hich control gains are scheduled w ith variablessuch as dynam ic pressure and Mach num ber, to m eet dynam ic re- sponse requirem ents in different flight conditions. Classicalgain-scheduling approaches m ay resultin som e problem s, w hich can not guarantee globalrobustness and stability in transitions of different flight conditions. Gain-scheduling problem is system atically investigated from robustness point of view in the paper. Detailed procedures for gain-scheduled controller to achieve both robustness and stability perform ance are given and applied to a typicalflight controlsystem . For sw itching stability problem s ofdifferentflightconditionsin flightcontrolsystem s, a new approach isproposed, in w hich differentflight conditions are reduced into a param eter varying plant using interpolation firstly, and then param eter-varying controller design goes next. Though interpolation errors m ay exist, the ro- bustparam etervarying controller design can com pensate forthose uncertaintiesand errors, and final- ly achieve good perform ance ofrobustnessand sw itching stability during transitions. Illustrative sim - ulation atlastshow s satisfactory results.