Real-Time Dynamic Modeling: Data Information Requirements and Flight-Test Results

Abstract

Practical aspects of identifying dynamic models for aircraft in real time were studied. Topics included the formulation of an equation-error method in the frequency domain to estimate nondimensional stability and control derivatives in real time, data information content for accurate modeling results, speed of convergence, and data information management techniques such as data forgetting, incorporating prior information, and optimized excitation. Real-time dynamic modeling was applied to simulation data and flight-test data from a modified F-15B fighter aircraft and to operational flight data from a subscale jet transport aircraft. Estimated parameter standard errors, prediction cases, and comparisons with results from postflight analysis using the output-error method in the time domain were used to demonstrate the accuracy of the identified real-time models.Nomenclature a x , a y , a z = body-axis translational accelerometer measurements, g or ft=s

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Real-Time Aerodynamic Parameter Estimation Without Air Flow Angle Measurements

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