A simple active controller to suppress helicopter air resonance in hover and forward flightA coupled rotor/fuselage helicopter analysis with the important effects of blade torsional flexibility, unsteady aerodynamics, and forward flight is presented. This model is used to illustrate the effect of unsteady aerodynamics, forward flight, and torsional flexibility on air resonance. Next, a nominal configuration, which experiences air resonance in forward flight, is selected. A simple multivariable compensator using conventional swashplate inputs and a single body roll rate measurement is then designed. The controller design is based on a linear estimator in conjunction with optimal feedback gains, and the design is done in the frequency domain using the loop-transfer recovery method. The controller is shown to suppress the air resonance instability throughout wide range helicopter loading conditions and forward flight speeds.
Document ID
19900029466
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Friedmann, P. P. (California Univ. Los Angeles, CA, United States)
Takahashi, M. D. (California, University Los Angeles, United States)
Date Acquired
August 14, 2013
Publication Date
January 1, 1989
Subject Category
Aircraft Stability And Control
Meeting Information
Meeting: IUTAM/IFAC Symposium on Dynamics of Controlled Mechanical Sytems