CD Drag coefficient FT Thrust (N)

This paper presents the results of an investigation related to the estimation of lateral-directional aerodynamic derivatives of highly augmented and advanced fighter aircraft from the flight like response data. Different types of pilot inputs are used to generate aircraft response data in the engineer-in-loop flight simulator to determine which input excitation might provide the most accurate estimates of aircraft stability and control derivatives. Also, MATLAB / SIMULINK-based simulation platform is used to generate aimaft response with single-surface excitation to evaluate the usefulness of the method for d control derivatives estimation. The maximum likelihood estimation, based on output error min ' 'sa 'on technique, is used to estimate the derivatives from the aircraft simulation response data. The re s?r Its indicate that accuracy of the estimated derivatives improve with persistence excitation and single-surface excitation