基于观测量扩充的捷联惯导快速初始对准方法

Fast alignment method of SINS using measurement augmentation

近似静止状态时捷联惯导系统可观测性较差,利用卡尔曼滤波完成初始对准需要较长时间。针对这一问题提出了一种基于观测量扩充的捷联惯导系统快速初始对准方法。在不改变系统状态方程的情况下,将速度误差和地球转速作为系统观测量。并根据观测量的扩展详细地推导了观测方程,进而利用扩展卡尔曼滤波完成捷联惯导系统初始对准。车载试验结果表明,与传统的卡尔曼滤波对准方法相比,新方法在保证初始对准精度的同时缩短了初始对准时间。

During approximate stationary alignment, ohservability of strapdown inertial navigation systems （SINS） is so weak that the long duration is needed to accomplish initial alignment. In order to solve this problem, a SINS rapid alignment method based on augmented measurements is proposed. Velocity error and earth angular rate are considered as measurements without changing state equations. Measurement equations are de- duced according to the augmented measurements. An extended Kalman filter （EKF） is also used for SINS initial alignment. Vehicular test results show that the new method not only converges more quickly but has the similar accuracy, compared with the conventional Kalman filter method.