Identification of aircraft and rotorcraft aeroelastic modes using state space system identification

Real time identification of various structural modes of the military fighter aircraft and rotorcaft is a serious problem. If these modes are not identified accurately, aeroservoelastic instabilities may occur. In this paper, we study the identification of these structural modes using both the simulated and real data with two powerful system identification techniques known as the stochastic realization algorithm (SRA) and deterministic SRA (DSRA). These techniques can extract structural mode parameters (frequencies, damping and mode shapes) from limited amounts of data under poor signal-to-noise ratio conditions and can be implemented online. The performance of these algorithms has been shown to be superior to those of other currently available methods on both simulated and real data from F-16 and V-22 aircraft.