Data Compatibility Check & Reconstruction And Research On Identification Of Flight Dynamic Model

As a key technology for aircraft design,control law design and stabilization analysis,system identification has been increasingly attractive.The parameterized model identification of fixed-wing aircraft,in the paper,was studied based on the research of data compatibility check and reconstruction and preprocessing,nonparametric model identification,mechanism modeling,input signal and flight test design.At the same time,the parameterized model identification of the helicopter has also been studied,and its result was compared with that of the fixed-wing aircraft,and the differences between the two identification were figured out.Firstly,theoretical basis that this paper studies was introduced.The application scope of the identification algorithms,such as the state subspace algorithm and the prediction error algorithm and others,was studied in this paper.The nonlinear flight dynamics model has been established based on the mechanism model and the linearization has been conducted using the "small perturbation" theory.At the same time,the characteristics of flight mechanics was studied providing a priori knowledge for the parametric model identification.Secondly,the requirements of input signal and flight test were analyzed,and the non-parametric model identification was also analyzed by using improved spectrum estimation,frequency response regularization and composite window technology.Thirdly,some algorithms of compatibility check and reconstruction of the test data was studied.Then,the extended Calman filter algorithm has been used for compatibility check and reconstruction of the test data,the quality of which was improved.What`s more,the preprocessing of the test data was also carried out,including field values elimination and correction,sensors position correction,detrending and filtering.Finally,the parametric model of the fixed wing aircraft has been identified,and the parameter confidence of the model were analyzed by using the Cramer-Rao boundary and insensitivity.Some differences have been pointed out by comparing the identification of aircraft with helicopter.In addition,on the basis of system parameterized model identification software developed in the past using MATLAB/GUI,the software was further improved and optimized by adding compatibility check and reconstruction and parameter confidence module.