陆用惯性导航系统非线性对准方法

以某型自行火炮炮载惯性导航系统为研究对象。为解决大方位失准角造成的系统非线性问题，在对大失准角误差模型进行详细分析的基础上，提出了基于快速正交搜索（FOS）和卡尔曼滤波（KF）的非线性参数估计方法。利用事先训练好的非线性误差模型进行对准，既能消除线性姿态误差，又可以对非线性姿态误差起到良好的抑制作用。仿真结果表明，FOS/KF方法的对准精度和实时性远优于扩展卡尔曼滤波（EKF）。对比试验结果表明，单独使用EKF时的方位角误差最大达到14.99°，而FOS/KF可以使方位角误差保持在0.8°以内。FOS/KF方法的估计精度不随系统非线性程度的变化而变化，并且不需要进行粗对准，简化了对准过程，提高了载体机动性。

Nonlinear alignment method for land SINS

The gun-board Strapdown Inertial Navigation System (SINS) is discussed. To solve the problem of system non-linear caused by the large azimuth misalignment angle, a non-linear parameter estimation method based on Fast Orthogonal Search (FOS) and Kalman Filter (KF) is proposed after a detailed analysis of the model for estimation of large misalignment angle errors. The non-linear error model previously trained is used for alignment. The linear attitude error can be eliminated, and the nonlinear attitude error can be suppressed effectively. The simulation results show that the FOS/KF method can result in more alignment accuraty and real-time than the Extended Kalman Filter (EKF). With a comparison of the test results shows that the azimuth angle error is up to 14.99° when the EKF is used alone, while the azimuth angle error is within 0.8° when the FOS/KF method is used. The accuracy of estimation with FOS/KF method does not change with nonlinearity of the system and does not need coarse alignment, simplifying the alignment process and improving the carrier maneuverability effectively.