Multi-Input Multi-Output Flight Data Analysis with HHT

摘要

This research investigates the utility of the Hilbert Huang Transform (HHT) for the analysis of aeroelastic multi-input multi-output (MIMO) flight data. The recently-developed Hilbert Huang algorithm addresses the limitations of the classical Hilbert transform through a process known as empirical mode decomposition. Using this approach, the data is filtered into a series of intrinsic mode functions, each of which admits a well-behaved Hilbert transform. In this manner, the Hilbert Huang algorithm affords time-frequency analysis of a large class of signals. The purpose of this research is to demonstrate the potential applications of the Hilbert Huang algorithm for the analysis of multi-loop aeroelastic systems. Applications for correlations between system input and output, and among output sensors, characterize the time-varying amplitude and frequency correlations present in the various components of multiple data channels. Online stability analyses and modal identification are new applications for the algorithm, particularly in the area of aeroelastic and aeroservoelastic systems analysis.