Closed-loop Identification Of Aerodynamic Parameters For Hypersonic Vehicle

The aerodynamic parameters of hypersonic aircraft are with stronguncertainties and the model of aerodynamic is hard to build, because of its highflight speed, large range of altitude variation and many other factors. In thispaper, Winged-Cone is used for aerodynamic parameters identification, which isa general model of hypersonic aircraft announced by Langley Research Center,the U.S. The main work of the paper are summarized as follows：Firstly, the research status of aerodynamic parameter identification wasintroduced and chapters were arranged.Secondly, linear model of aerodynamic parameter was deduced usingaerodynamic parameter fitting formula of Winged-Cone aircraft under a fixedMach number and angle of attack. Small disturbance linear motion equation ofstate was deduced at a reference point at gliding section of hypersonic aircraft.This model was used for aerodynamic parameters identification.Thirdly, least squares and maximum likelihood estimation method was usedfor identifying the longitudinal and lateral aerodynamic parameters of the aircraft.Identifiability analysis of the longitudinal and lateral system using the conditionnumber of iteration matrix. Using Singular value decomposition method foraerodynamic parameter identifiability, given the identifiability order ofaerodynamic parameters.Fourth, based on the Identifiability analysis of aerodynamic parameters andfrequency characteristics of the aircraft, designed dipole square wave input signaland multi-sinusoidal input signal, and the incentive effects of the two inputsignals are compared and analyzed.Finally, the trajectory of hypersonic vehicle at aerodynamic parameter identification section was simulated, the influence of the input signal for thetrajectory of the aircraft was analyzed.