针对战术级捷联惯导系统的初始对准,提出一种姿态自对准、方位外部装订的半自对准方案。首先,对更新周期内的加速度计输出进行积分,完成水平姿态计算。在水平对准结束时,引入外部基准航向,得到姿态四元数,完成对准过程。此外在陀螺仅存在常值漂移的假设下,利用对准结果,可对常值漂移进行粗略估计,结果用于陀螺输出补偿可提升导航精度。仿真结果表明,在三轴摇摆运动条件下,水平对准精度达0.1°以内。

Aiming at the problem of tactical SINS initial alignment, an alignment algorithm where leveling attitudes are calculated by inertial measurements of SINS, while the azimuth is set by external is proposed. Firstly, integrating the output of accelerometers over the sample time interval is used to update the quaternion. After level aligning, attitude quaternion is obtained to fulfill alignment by setting external azimuth. Furthermore, a nice feature is that the alignment scheme can estimate constant gyro biases according to the result of alignment with the assumption that the gyro outputs are only contaminated by constant biases. Finally, simulated programs are carried out that demonstrate the efficiency, and the results indicate that the horizontal precisions are within 0.1° under the sway maneuver.