用极大似然法辨识轴对称飞行器的气动参数

 采用极大似然法完成了轴对称飞行器的非线性气动参数辨识。根据飞行弹道的特性，采用考虑了横侧向运动耦合的纵向三自由度飞行动力学模型；为了反映气动参数随马赫数的变化，给出了一种考虑马赫数变化的气动参数数学模型，并采用了分段辨识的技巧；通过采用建模前估计法的辨识结果作为极大似然法的初值，保证了极大似然法的收敛，计算结果表明：这种算法对大攻角下的非线性气动参数能获得满意的辨识结果。

IDENTIFICATION OF AERODYNAMIC COEFFICIENTS USING MAXIMUM LIKELIHOOD METHOD

A nonlinear aerodynamic model for a symmetric vehicle has been identified by applying the maximum likelihood technique to flight testing data. In accordance with the characters of the flight, a three degree of freedom method of the longitudinal motion equations coupled with lateral motion parameters is adopted. A new mathematical model of nonlinear aerodynamics including the influence of Mach number is presented. The results show that the method is particularly applicable to estimating nonlinear aerodynamic coefficients at high angles of attack.