小卫星动平衡研究--质心不对中对姿态的影响

首先定性分析质心不对中对星体动力学特性的影响，然后由拉格朗日第二类方程导出引力场下星体运动方程的矩阵表达式，最后以50kg级长方体3轴稳定小卫星为例，分析不同初角速度和不同时间历程情况下质心不对中对星体运动姿态的影响，并分析其对星体运动稳定性的影响．本文研究为同类品种小卫星的构型设计、姿态控制系统设计以及制定卫星动平衡精度提供依据。

THE EFFECT OF DISPLACEMENT OF MASS CENTER ON THE ATTITUDE OF SMALL SATELLITES

Contributions on attitude of small satellite have mainly placed emphasize on control system, such as system design, method of control, control algorithms, mathematical model, attitude simulation and the like, but few papers have been published on the relation between attitude stabilization and mass center of small satellites. This paper analyzes effect of the displacement of mass center on attitude of small satellites from the view of structure design and dynamical balancing in light of ellipsoid of kinetic energy and motion equation. The motion equation in this paper is deduced from Lagrange equation of second kind, and represented in terms of matrix to benefit solving the equation by computer and also to make the equation concise. By the equation, the numerical simulations of attitude are carried out for a 50kg small satellite corresponding to different initial angular velocities and different displacements of mass center. The effect of displacement of mass center on stability of motion of small satellites is also analyzed. The simulations and analysis show that one or several optimal displacement of mass center exists both for attitude stabilization and stability of motion. This paper aims at providing reference for structure design, attitude control, as well as for determining the precision of dynamic balancing.