直升机飞行动力学高阶线性系统建模

针对常规单旋翼带尾浆直升机，从复杂的飞行动力学非线性数学模型入手，采用数值方法在平衡点处求出线性模型；该线性模型包括传统的６自由度刚性机体模型，还包括主桨和尾浆动力入流、主桨和尾桨挥舞自由度，其状态空间形式具有２５个状态变量（５简称２５状态模型）。以某型直升机为例，对线性模型与非线性模型的时域动态响应，及２５状态高阶线性模型和传统６自由度９状态模型的特征值进行了比较，验证了建模方法的可靠性和精度。

High Order Linearized Model of Helicopter Flight Dynamics

For the current helicopter of single rotor with tail rotor, the high order linear model is set up in this paper, using digital differential method from the complicated nonlinear model of helicopter flight dynamics. The high order linear space state model has 25 state variables, including six degrees of freedom of rigid fuselage, flap motion of main and tail rotor, non uniform dynamic inflow at rotor plane. For a sample helicopter, during the whole flight speed, linear model is compared with nonlinear model about dynamic response in time domain, and eigenvalues of 25 states linear model is compared with 9 states linear model(traditional linear model only with rigid fuselage), then the precision of high order linear model is validated.