箭载捷联惯性导航系统初始对准技术研究

Research on Alignment of Launch Vehicle Strapdown Inertial Navigation System

为同时提高运载火箭捷联惯导系统(SINS)的对准精度、缩短对准时间,采取经典的粗对准与精对准两步对准法。在粗对准阶段,由惯性仪表的测量信息解析计算惯测组合坐标系到数学平台系的角位置关系,建立初始方向余弦矩阵Cn′b;在精对准阶段,采用四元数法推导出激光陀螺SINS数学平台角误差和速度误差方程。并以此建立初始对准误差模型,采用卡尔曼滤波(KF)进行精对准。数字仿真结果表明该模型有效,能满足初始对准精度和对准时间的要求。

To improve the alignment accuracy and decrease the alignment time of strapdown inertial navigation system (INS) simultaneously, a two-stage method for alignment, which included rough alignment and extractive alignment, was presented in this paper. In the rough alignment stage, the original quaternion matrix was calculated by the output of inertial measure unit. In the extractive alignment stage, the strapdown INS mathematics platform angle and velocity difference equations were derived from quaternion, and correspondingly using Kalman filter(KF)in the alignment error model. Some KF was designed after available analysis. The digital simulation results showed that the model could not only reduce sensitivity to noise and random drift, but also quicken the measurement process.