An experimental program has been conducted to demonstrate the benefits of applying active rotor control techniques to improve aeromechanical stability characteristics of a Bearingless Main Rotor (BMR) model. The model is based on a four-bladed concept with a flexure, between the hub and each blade, which accomodates flatwise, edgewise and torsional (pitch) motions. The flexure is enclosed by a torsionally stiff cuff that is cantilevered to the blade/flexure joint at its outboard and shear-restrained to the flexure at its inboard end. The shear-restraint includes an elastomeric damper to stabilize edgewise motion. The model was tested in hover over a range of rotor thrust and rotational speed conditions. Numerous data were acquired for uncontrolled or open-loop and closed-loop feedback control, with the latter using fuselage state parameter feedback. The state parameters included fuselage pylon position and velocity, applied individually in both pitch and roll directions. The control approach used a fixed-gain controller which transformed the fuselage state measurements into swashplate cyclic commands. The results in this paper show that aeromechanical stability margins can be greatly improved, and instabilities occuring within the operating envelope eliminated, by the application of active control.


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    Title :

    Fuselage state feedback for aeromechanical stability augmentation of a bearingless main rotor


    Additional title:

    Kabinenzustandsparameter-Feedback zur Verbesserung der aeromechanischen Stabilität eines lagerlosen Hauptrotors


    Contributors:

    Published in:

    Publication date :

    1996


    Size :

    9 Seiten, 13 Bilder, 4 Tabellen, 6 Quellen




    Type of media :

    Article (Journal)


    Type of material :

    Print


    Language :

    English