基于惯性空间稳定的双轴惯导旋转调制方法

陀螺标度因数误差是影响长航时船用旋转调制惯导系统的关键误差源，其与地球自转和载体运动的耦合误差，可导致惯导系统误差发散。针对此问题，结合船用惯导使用特点，采用外航向、内俯仰的双轴旋转框架结构。在此基础上，提出了一种基于惯性系的双轴旋转惯导系统多位置转停调制方案，通过补偿地球自转和载体运动在双轴旋转惯导内外框架旋转轴上的投影分量，可显著降低陀螺标度因数误差对长航时导航精度的影响。数学仿真和船载试验结果表明，在载体航向角运动的场景下，该方法与传统的双轴旋转调制方案相比可有效抑制地球周期项振幅的增大，系统导航位置误差的发散也降低50%以上。

A dual-axis inertial navigation system rotation modulation method stabilised in the inertial coordinate system

Gyro scale factor error is the key error source, affecting the long-endurance marine rotary-modulation inertial navigation system. And its coupling error with the Earth rotation and carrier angular motion can lead to the error divergence of the inertial navigation system. Aiming at this problem, combined with the characteristics of marine inertial navigation system, a dual-axis rotating framework with outer heading and inner pitch is adopted. Based on the inertial coordinate system, a multi-position rotation-stop modulation scheme for the dual-axis inertial navigation system is proposed. By compensating projection components of the Earth rotation and carrier angular motion in the plane of the rotating shaft, the influence of gyro scale factor error is significantly reduced in long endurance. Mathematical simulation and shipboard test results show that, compared to the conventional two-axis rotational modulation scheme, this method can effectively suppress the increase in the amplitude of the Earth''s periodic term, and reduce the dispersion of the system''s navigation position error by more than 50%.