船用捷联惯性导航系统惯性系快速对准算法

为满足船用捷联惯性导航系统对准快速性和精确性的要求，提出一种系泊条件下的捷联惯导系统快速初始对准方法。利用三阶调平回路进行水平精对准，直接计算出重力加速度在基座惯性坐标系下的投影，并采用加权求平均算法对重力加速度的投影进行平滑。最后根据惯性系下重力加速度慢速圆锥变化的特性，利用平滑后的重力加速度实现舰载捷联惯导快速初始对准。对所提出的快速对准算法进行了仿真，并利用系泊实验进一步验证了惯性系快速对准方案的可行性。结果表明，所提出的快速对准方法在6分钟内完成了初始对准，且对准精度满足中等精度捷联惯导系统要求。

Fast Alignment Algorithm Based on Inertial Frame for Shipboard SINS

In order to satisfy the requirements of rapid and precise alignment for shipboard strapdown inertial navigation system（SINS）, the fast alignment algorithm based on inertial frame is proposed. The third order leveling loop is used for leveling alignment, then the projection of the gravitational acceleration in the base inertial frame is calculated directly and smoothed based on the average algorithm by weigh- ting. According to the gravitational acceleration presents the coning motion in the inertial frame, by using the information of the gravitational acceleration which has been smoothed, fast alignment for shipboard SINS is accomplished. The alignment method is simulated and a mooring experiment is used to validate the feasibility of the alignment method. Experiment results show that, the precision of the fast initial alignment algorithm achieves the medium navigation accuracy requirement in 6 minutes.