制导炮弹捷联惯导基于GPS的飞行中对准算法(英文)

SINS in-flight alignment algorithm based on GPS for guided artillery shell

提出了一种适用于制导炮弹上低精度MEMS IMU/GPS组合系统的飞行中初始对准算法。通过引入辅助的载体惯性系和导航惯性系,将所求姿态四元数分解为三部分:第一部分描述载体系相对于载体惯性系的姿态,由MEMS陀螺仪输出积分求解;第二部分描述导航系相对于导航惯性系的姿态,利用GPS位置输出解析求解;第三部分描述两辅助惯性系的相对姿态,采用Re-quest算法完成解算。详细讨论了算法误差、有效性条件,并对Re-quest算法进行了优化和简化。蒙特卡洛仿真结果表明,在弹体加速度以指数规律变化条件下,对准算法可以在10 s时间内达到水平误差小于0.2°(1?)、航向误差小于0.4°(1σ)的精度,完全满足制导炮弹组合系统初始对准的精度要求。

An SINS in-flight alignment algorithm is proposed for the guided artillery shell in which a low-cost MEMS IMU/GPS integrated system is equipped. The algorithm decomposes the attitude quaternion into three parts： inertial rate, separate Earth motion, and a constant quaternion. The first two parts are solved based on MEMS gyros＇ measurement and GPS position information respectively, and the constant quaternion is solved by using Re-quest method. The errors and effective conditions of the proposed algorithm are discussed, and the Re-quest method is optimized and simplified. The results of Monte Carlo simulation show that the level errors are less than 0.2° （1σ） and the heading error is less than 0.4° （1 σ） within 10 s, meeting the SINS alignment＇s accuracy requirement of the guided artillery shell.