By this means, it can eliminate the affection of the abnormal measure data, and to keep the covariance of the filter to be zero.Finally it can achieve the optimal estimate.

• 从而可以消除异常的测量数据带来的影响，使滤波器的残差始终保持零均值，且使估计误差的协方差阵收敛，最终实现最优估计。