基于四元数的捷联惯导惯性系晃动基座自对准算法

为提高捷联惯导系统在晃动基座下初始对准的快速性和精度,提出了一种基于四元数的捷联惯导惯性系晃动基座自对准算法.该算法利用惯性坐标系下的姿态更新来实时地反映载体在晃动干扰下的姿态变化,通过四元数推导将初始姿态的最优估计转化为Wahba姿态确定问题,以消除角晃动干扰的影响;并根据惯性系下重力矢量和晃动干扰加速度不同频的特点,引入小波阈值消噪以消除线振动干扰的影响,从而提高算法在晃动基座下的对准精度.仿真结果表明,该算法不需要进行粗对准,具有角晃动干扰隔离能力和线振动干扰抑制能力,能够实现晃动基座下的快速、精确自对准.

SINS Self Alignment Algorithm with Inertial Frame for Swaying Base Based on Quaternion

Abstract： To improve the rapidity and precision of initial alignment for strapdown inertial navigation system (SINS) under swaying base, the SINS self alignment algorithm with inertial frame for the swaying base based on quaternion was presented, which used attitude update of inertial coordinates to reflect the gesture changes of the carrier under real time shaking interference. The algorithm transformed the optimal estimation of the initial attitude into the Wahba problem to remove the angular interrupting by quaternion derivation, and used the wavelet de noising threshold to eliminate the linear vibration interrupting according to the different frequency characteristics of gravity vector in inertial reference frame and the disturbance. The simulation results show that the presented method can accomplish the alignment quickly and accurately under swaying base even in the presence of angular motion and linear vibration interference without the coarse alignment process.