Hypersonic Flight Vehicle Aerodynamic Parameters Identification And Input Design Technology Research

In this paper, aerodynamic parameter identification for hypersonic vehicle is studied. Active excitation technique is studied at the basis of the characteristics of hypersonic aircraft model analysis. Hypersonic flight simulation and UAV flight demonstration are to validate the feasibility of multisine input and contrast211and multisine input. In addition, in that the Newton-Raphson algorithm requires an initial value and is easy to fall into local optimal value, etc, the paper design PSO algorithm based on maximum likelihood criterion.The main work and results of this paper are as follows:Firstly, the model features of the hypersonic aircraft are analyzed. The hypersonic flight vehicle characteristics of rapid changes in the state are studied. Nonlinear aerodynamic parameters are analyzed. Uncertainty of dynamic pressure measurement, dynamic derivative measurement, and models is discussed. The overall identification scheme based on characteristics object.Secondly, the design scheme and evaluation criteria of input signal for hypersonic vehicle are studied and validated based on the flight mission. In order to obtain better identification results, active excitation is required to motivate the motion modes of the vehicle. The principle of stimulation design is studied, the feature of typical input is analyzed and the scheme of input is established. The scheme of multiple-input is designed, aiming at the requirement of hypersonic vehicle. The principles of parameters measures and non-parameters measures are given. The necessity, the excitation way, the design criteria for amplitude and frequency of active stimulation are studied through the hypersonic vehicle model simulation. Multisine and are compared with211input when feedback control system is oprerating. For there is no engineering precedent applying multisine input to in domestic, multisine input is validated on the unmanned aerial vehicle (UAV) platform.Thirdly, for hypersonic vehicle longitudinal nonlinear characteristic, the nonlinear characteristic candidate model described by higher-order aerodynamic parameters is designed and nonlinear identification of aerodynamic parameters is realized.Finally, the particle swarm optimization based on the maximum likelihood criterion is developed to estimate the aerodynamic parameters of hypersonic vehicle. Then the designed optimization algorithm is applied on the data of hypersonic vehicle model simulation and obtains good identification results.