The Research On Model Identification Of Mi Cro-Small Tiltrotor Aircraft In Helicopter Mode

Aiming at a certain type of micro-small tiltrotor aircraft designed by Nanjing University of Aeronautics, aircraft modeling method based on system identification is studied in this paper. Work of the paper mainly includes 4 parts:Firstly, the 6 DOF airframe motion equations of micro tiltrotor aircraft in helicopter mode are built, and the angle-velocity transfer function model is determined through the small disturbance li-nearization and transverse/longitudinal decoupling, which is a reference for model structure identifi-cation.Secondly, Design the flight bracket for ground simulation and data acquisition device for mi-cro-small tiltrotor aircraft,which are used to collect angle-velocity data of micro-small tiltrotor air-craft.Then, the identification test is designed,including design of identification input signal, choice of Sampling frequency and length of data,identification test data pretreatment.At last,based on test data and the class of angle-velocity model,the optimization of angle-velocity model is obtained through the method of model structure identification; the model parameters are identified separately by nonlinear and separable least-squar method, the model validation shows the method gets good angle-velocity model, amend the deficiency of tradition method.