Model simplification methods for a reduced order system of flexible aircraft

The analysis of the aircraft model with aeroelastic interactions is extremely difficult task since the size of the flexible aircraft models is complex. This paper compares the model simplification methods to obtain low order mathematical model of a flexible aircraft, which is appropriate for control law design. In the present investigation, higher order mathematical model of Flexible aircraft is reduced to the equivalent 4th order aircraft dynamics. The different five model simplification methods are used for this purpose. They are Balanced Realization, Truncation, Residualization, Moment Matching and Pade's approximation. The comparative study of these methods shows that Balanced Realization, Residualization and Truncation are the best model order reduction techniques that can be applied for obtaining the reduced order model of flexible aircraft.