基于Gibbs矢量估计卫星轨道姿态的滤波算法研究

针对“矢量观测 陀螺”这种典型的三轴稳定卫星姿态确定系统模式,引入具有四元数优越性的Gibbs矢量作为姿态参数,提出了一种新的具有良好实时性能的轨道姿态估计方案。在方案设计中,为描述卫星轨道姿态的Gibbs矢量,推导出了基于四元数的运动学方程,并将QUEST法作为处理多矢量观测信息的压缩技术引入估计器,使得滤波修正算法得以简化。另外,针对单矢量观测情况,给出了能够加快状态估值收敛速度的改进协方差修正算法。仿真结果验证,新方案的姿态估计精度与传统的欧拉角估计法相当,而运算效率却明显高于欧拉角估计法。

Filtering Algorithm of a Satellite Orbital Attitude Estimator Based on Gibbs Vector

A new real-time filtering algorithm for orbital attitude estimation of three-axis stabilized satellite is presented for the typical attitude determination mode composed of vector observations and gyros. The satellite orbital attitude is expressed by the Gibbs vector based on the orbital attitude quaternion. The compact differential equations governing the change of the Gibbs vector are derived according to the relation between the orbital attitude and the inertial attitude. And the QUEST algorithm is efficiently combined into the attitude estimator as the compressing technique of multi-vector observation information in order to simplify the update implementation. In addition, a modified method is given for the covariance matrix updating in the case of one vector observation. Simulation results demonstrate that the attitude estimation accuracy using the new filtering algorithm is similar to that using the traditional Euler-Angle estimation algorithm, but the computation efficiency of the former is obviously higher than that of the latter.