Adaptive mode suppression scheme for an aeroelastic airbreathing hypersonic cruise vehicle

Abstract

This paper presents an adaptive mode suppression scheme that is simulated on a longitudinal model of a generic airbreathing hypersonic flight vehicle. An aerodynamically optimized vehicle model is used which has a long slender configuration and flexible modes that are slow enough to get excited during normal operation and therefore pose a control issue. These elastic modes maybe cause adverse aeroservoelastic effects which can degrade the performance or even cause instabilities. The frequency and damping ratio of the flexible modes can be uncertain and also vary during flight due to atmospheric heating. A control scheme is presented which incorporates an adaptive notch filter which can accurately track and suppress an unknown or changing flexible mode online. The adaptive scheme is then compared to a non-adaptive scheme in simulations using an aeroelastic airbreathing hypersonic cruise vehicle model that has been previously developed. © 2008 by the American Institute of Aeronautics and Astronautics, Inc.