传统卡尔曼滤波对准只适用于中低纬度地区,不适用于极区。针对这一问题,提出惯性系下卡尔曼滤波对准作为极区对准方案。首先选择惯性系为对准坐标系,在惯性系内推导捷联惯导系统的速度误差方程和失准角方程,建立适用于极区对准的误差模型。以速度误差为观测量,结合误差模型建立卡尔曼滤波器并进行离散化处理。然后对该对准算法进行仿真,验证其在极区的可行性,并与传统的卡尔曼滤波对准的仿真结果进行对比。最后,分析不同速度和有加速运动等情况下该算法在极区的性能,为工程实践提供理论依据。
The traditional alignment method with Kalman filter is available in the low and middle latitude region, but not available in the polar region. For this issue, we propose the Kalman filter alignment under inertial frame as a solution. Firstly, the inertial frame is chosen to play the role of the alignment frame. The error model of a strapdown inertial navigation system which is applicable to the polar region alignment is derived un der the inertial frame. And the misalignment angle equation and the velocity error equation are included in the error model of the navigation system. In this paper, the velocity error is used as the measurement information and the discrete Kalman filter is obtained on the basis of the alignment error model. Secondly, simulations are implemented to evaluate the feasibility of the proposed alignment algorithm in polar regions, compared with the traditional alignment method with Kalman filter. Moreover, the performances of the proposed algorithm under different speeds and accelerations are specially analyzed in order to provide theoretical basis for practical applications.