二阶插值非线性滤波在卫星姿态确定中的应用

Study of second-order nonlinear interpolation filtering for satellite attitude determination

基于多项式插值近似,导出了具有良好实时性能的二阶插值非线性滤波算法,并将该算法应用于星光-陀螺模式下三轴稳定卫星的姿态确定中.这种姿态估计算法的实现非常简单,其运算量与传统的扩展卡尔曼滤波姿态估计算法相当,但滤波性能却与基于二阶泰勒级数近似得到的非线性姿态估计算法一致;而且,在二阶插值非线性姿态估计算法中,避免了由四元数正交约束所造成的协方差阵奇异性问题.

A second-order nonlinear filtering algorithm with good real-time performance is given based on the polynomial interpolation approximation. Using the algorithm the second-order nonlinear interpolation attitude estimator is developed for the typical stellar-inertial attitude determination system. The implementation of the new attitude estimation algorithm is significantly simpler. The computational burden of the new algorithm is comparable to that of the conventional extended Kalman attitude estimation algorithm. But the performance of the new algorithm is the same as that of the nonlinear attitude estimation algorithm based on second-order Taylor approximation. In addition, the singularity of the covariance matrix caused by the constraint on the attitude quatemion normalization is avoided in the second-order nonlinear interpolation attitude estimation algorithm.