捷联惯导系统静基座的高精度初始对准方法

High Precision Initial Alignment Method of Stationary Base in Strap-down Inertial Navigation System

针对捷联惯导系统静基座初始对准存在精度低的问题,通过加速度计和陀螺仪获得重力矢量和地球角速度矢量,采用解析方法快速地估算出一个满足要求的初始姿态矩阵。借助卡尔曼滤波模型对系统的误差进行分析,并建立系统的状态方程和量测方程,将系统失准角从干扰误差中估算出来,为导航计算提供精确的初始条件。仿真实验结果表明,将卡尔曼滤波技术引入到捷联惯导系统静基座的高精度初始对准过程中,使对准精度和收敛速度均得到了显著改善。

In order to deal with low accuracy of the stationary base in the strap-down inertial navigation system initial alignment,the author proposed a method of using accelerometers and gyroscopesthe to measure the Earth＇s gravity vector and angular velocity vector,and using the analytical method to estimate directly the initial posture matrix which meets the requirements for use. Then,the error is analyzed by Kalman filter model and a state equation and a measurement equation are established to estimate the system misalignment angle from interference error,that provides the accurate initial conditions for the navigation calculation. The simulation results show that the introduction of the Kalman filter into the high-precision initial alignment of stationary base in the strap-down inertial navigation system improves the alignment accuracy and convergence rate significantly.