抛物面天线柔性对焦点动特性的影响分析

为研究星体进行调姿运动时柔性抛物面天线的弹性变形对其视在相位中心的影响,建立了计算抛物面天线动态几何焦点的数学模型,并通过航天器动力学模型对姿态调整过程中天线焦点的动态响应进行数值求解.建立由抛物面天线、太阳帆板和中心星体组成的整星有限元模型,并求出天线无约束边界条件下的固有频率和振型.通过有限元模型和ADAMS联合仿真建立航天器零次刚柔耦合动力学模型并求得姿态调整过程中天线几何焦点的动态响应特性.结果表明,航天器进行姿态调整时,柔性天线面在做大范围整体运动的同时发生弹性振动,使其几何焦点在平衡位置震荡,严重影响星载天线的指向精度.

Effect of paraboloid antenna flexibility on geometric focus dynamic response

To study the effects of the elastic deformation of flexible paraboloid antenna on the approximate phase center in the stage of attitude adjustments, the mathematical model for solution paraboloid antenna dynamic geometric focus was established and its dynamic response characteristics were solved numerically. The FE model composed of the central platform,solar panels and paraboloid antenna was established and the natural frequencies and mode shapes of the antenna in unconstrained state were calculated. Then through co-simulation of FEM and ADAMS the zero-order rigid-flexible coupling dynamic model of the spacecraft was established, and the dynamic response of the antenna geometric focus in the process of attitude adjustments were obtained. Results show that the flexible attachments elastic vibration accompanves with rigid motions in the procedure of attitude adjustments, and the geometrical focus shock in the equilibrium position reduces spaceborne antenna pointing accuracy to some extent.