Filtering Structural Modes in Aircraft: Notch Filters vs Kalman Filters

Abstract

The disturbances to an airframe's sensors caused by the flexibility of the airframe is called structural coupling. Notch filters are currently used to attenuate the effect that the structural modes have on the aircraft's inertial flight control sensors. However, this approach is becoming more problematic with modern combat aircraft. A complex model which is representative of an agile combat aircraft has been developed, and a Kalman filter has been designed to reduce the effects of structural coupling. This work forms part of an ongoing project in conjunction with BAE Systems.