弹道导弹的捷联惯性/天文组合导航方法

Ballistic missile SINS/CNS integrated navigation method

针对传统的捷联惯性/天文(SINS/CNS)组合导航系统不能精确估计加速度计偏置而导致导航误差发散的问题,提出一种基于星光折射间接敏感地平的捷联惯性/天文(SINS/RCNS)组合导航方法。利用星敏感器测量星光折射角,结合大气折射模型得到的折射视高度来抑制位置误差的发散。推导了基于星光折射新的量测方程,分析了折射星数目与导航精度的关系,当使用多颗折射星时能够精确估计加速计偏置,从而能够完全抑制位置误差的发散,并对系统进行可观测性分析。通过卡尔曼滤波实现了状态估计。仿真结果表明:本文方法的导航精度优于传统方法,有效抑制了位置误差的发散,验证了本文方法的有效性。

Considering that traditional strap-down inertial/celestial integrated navigation system （SINS/CNS） cannot accurately estimate the accelerometer bias, which can cause the divergence of navigation errors, a strap-down inertial/celestial integrated navigation method based on the stellar refraction （SINS/RCNS） was proposed. The starlight refraction angle obtained from the stellar sensor and the apparent height obtained from atmospheric refraction model were combined to inhibit the divergence of position error. A novel measurement equation based on stellar refraction was developed and the relationship between the number of used refraction stars and navigation accuracy was analyzed. When multiple refraction stars are used, the proposed method can accurately estimate the accelerometer bias so that the position errors can be inhibited completely, and its observability was analyzed. The estimation of the state of system was realized through the Kalman filter. The simulation results indicate that the precision of navigation based on the proposed method is better than that of the traditional method and inhibits the divergence of the position error effectively, which shows the validation of the proposed method.