健康管理对老年冠心病危险因素治疗及控制率影响

捷联惯导系统(SINS)静基座初始对准中,过高的陀螺噪声不但导致系统状态方程非线性,也会使对失准角的估计不能收敛到真值.因此,提出了一种磁强计辅助对准方法,对系统观测方程的分析证明了该方法不仅可提高滤波精度,同时还可对磁场强度和磁倾角进行估计.非线性滤波采用平方根无迹卡尔曼滤波(SRUKF),SRUKF与无迹卡尔曼滤波(UKF)滤波精度相当,优于扩展卡尔曼滤波(EKF).相比UKF,SRUKF具有更高的计算效率和稳定性.仿真结果表明,该算法在陀螺噪声较高的情况下仍能满足SINS初始对准要求.

Initial Alignment for SINS Assisted by Magnetometers

In initial alignment for strapdown inertial navigation system (SINS),over too strong noise of gyros not only made the system functions nonlinear,but also made the estimation for misalignment angle converge to a false value.A new alignment method assisted by magnetometers was proposed. The analysis of observation functions proved that this method could promote the filtering precision. Meanwhile,the method could estimate the magnetic field intensity and the magnetic obliquity.Square-root unscented Kalman filter (SRUKF) was used for nonlinear filtering. The filtering precision of SRUKF was the same as unscented Kalman filter (UKF) and better than extended Kalman filter (EKF). SRUKF was much more efficient and stable than UKF. Simulation indicated that even if the noise of gyros was strong, the method was still suitable for initial alignment.