A novel piece-wise fast alignment method for strapdown inertial navigation system (SINS) stationary alignment using lifting wavelet is presented. First, the fine horizontal alignment is executed. After the fine horizontal alignment, a lifting wavelet algorithm is utilized to de-noise the output of the gyros, and the azimuth mis-alignment angle is rapidly calculated. Theoretical analysis and practical experiment show that the lifting wavelet algorithm is effective to the de-noising of fiber optic gyro. Compared with the method using Kalman filter in the whole process of the alignment, this method has the same steady-state accuracy, but in the process of the fine azimuth alignment, the mechanical arrangement of SINS is not needed, and the time of fine alignment can be shortened to 30 s or so. This method makes up the defect that the convergence speed of the azimuth misalignment angle is slow, and accelerates the initial alignment process.%提出了一种利用提升小波进行消噪的捷联惯性导航系统(strapdown inertial navigation system,SINS)分段快速时准新方法.该方法首先进行水平精对准,然后利用提升小波算法对陀螺仪的输出信号进行消噪后,快速计算出方位失准角并进行修正,完成对准过程.理论分析和实际系统试验表明:提升小波算法对于光纤陀螺信号具有良好的消噪效果,新方法与传统的Kalman滤波对准方法具有相同的稳态精度,但方位精对准过程中,不需要进行捷联惯导的力学编排,精对准的时间可以缩短至30 s左右.该方法弥补了传统Kalman滤波精对准方法中方位失准角估计速度慢的缺陷,大幅度提高了SINS的初始对准速度.
展开▼
