基于四元数的舰船捷联惯导粗对准方法研究

摘要

Earth-rate rotation information cannot be measured by gyros due to wave action when ship is moored.Aiming to overcome these difficulties,an inertial coordinate based coarse alignment method is introduced.Attitude matrix is given using quaternion.The estimator is based on the decomposition of the attitude quaternion into separate quaternions.By this method,the algorithm is simplified and the computational time is reduced.Simulation results show that the algorithm estimates the ship's heading to within a few degrees and pitch/roll to within a few tenths of a degree to allow the fine alignment filter to operate within its linear region.%当舰船处于系泊和锚泊状态时,受风浪作用陀螺仪无法提取出地球自转角速度信息,从而导致粗对准解析法失效.针对这一问题,提出一种基于惯性坐标系的粗对准算法.采用四元数法表示舰船姿态,将所求初始姿态四元数分解成3部分分别进行求解.应用惯性坐标系方法及四元数法表述使得算法简单,计算机时少.仿真结果表明,在系泊和锚泊状态下,经算法解算出的姿态误差角在粗对准要求的范围内,完全可以满足后续的精对准要求.