基于传递函数的星箭耦合载荷分析

Dynamic response of the rocket and satellite coupled system based on frequency responses with rational function approximations

分别对运载火箭和卫星进行频率响应分析。在取得离散形式的频率响应分析结果基础上,采用有理多项式拟合技术,将火箭和卫星的频率响应函数转化成以部分分式表示的传递函数。根据星-箭对接的力学条件,可以在Simulink平台上建立起星箭耦合载荷系统模型。对此模型进行仿真便可得到在外力作用下星箭耦合载荷系统的瞬态动力响应。分别以简单的质量-弹簧模型、以及星箭耦合载荷模型验证了方法的正确性。基于传递函数的星箭耦合载荷分析方法,将柔性结构的动力学计算纳入到系统仿真的框架之中,为进一步实现结构-气动和伺服控制系统的耦合分析奠定了基础。该方法也为将火箭和卫星实测的频响特性直接应用于星箭耦合载荷分析创造了条件。

A general methodology was introduced for analyzing transient dynamic responses of the rocket and satellite coupled system based on frequency responses with rational function approximations.In light of the discrete frequency response functions of the rocket and satellite respectively calculated by finite element method,the rocket and satellite coupled model was achieved according to the condition of continuous displacement or force equilibrium.Details and practical implementation of the method were demonstrated by using a simple mass-stiffness system and a real type of rocket and satellite coupled model.The procedure is also shown to be advantageous for solving the transient dynamic responses of the rocket and satellite coupled system from the actually measured frequency responses characteristics.