Airplane Aerodynamic Parameters Identification and Fast Modeling Based on Equivalent System

Considering the characteristics of strong nonlinear coupling,complex aerodynamic parameters and long modeling process of the current large civil aircraft,a new method of fast modeling based on input and output analysis was proposed.The method employs the concept of low-order equivalent system used in flying qualities evaluation and gets the low-order model of the airplane through its time-domain or frequency-domain analysis,and then the linear equations of the airplane can be deduced.If the parameter mismatch is small,the results are of high reliability.Two applications in both linear system and nonlinear system prove its feasibility.