晃动基座下正向-正向回溯初始对准方法

针对传统方式需要对准时间长的问题，提出一种晃动基座下正向-正向回溯初始对准方法，实现了快速初始对准的目的。首先，给出了导航惯性系粗对准的基本原理，分析了导航惯性系粗对准在回溯过程中的作用。其次，对捷联惯导系统初始对准过程进行了深入的研究，利用导航惯性系建立精对准系统误差模型，将晃动基座时变姿态误差角估计问题转换为时不变姿态误差角估计问题，进而为正向-正向回溯对准奠定了理论基础。在此基础上，详细分析了正向-正向回溯对准的基本原理和设计方法。最后，通过设计仿真实验，验证了本文设计的对准方法可以在303 s内实现晃动基座上航向误差优于0.1°的对准精度。试验结果表明，本文提出的方法具有计算效率高、对准时间短、对准精度高的优点。

A Forward Forward Backtracking Alignment Method for SINS on Swaying Base

 Due to the long alignment time of the traditional method,a novel forward-forward backtracking alignment method is proposed to faster the alignment procedure. Firstly, the fundamental of the navigational inertial-frame coarse alignment is described, and the effect of the navigational inertial-frame coarse alignment is analyzed. Secondly, the principle of the initial alignment method of SINS is deeply explored. Based on the navigational inertial-frame error model, the time-varying error attitude estimation is transformed into a time-invariant error attitude estimation, then the forward-forward backtracking alignment method can be devised by this transformation. Moreover, the fundamental of the forward-forward backtracking alignment method is investigated in detail. Finally, the simulation and turntable test are conducted for validating the performance of the proposed method, and the results show that the errors of yaw are less than 0.1° when the whole alignment procedure lasts for 303 s. Thus, the proposed method has the advantages of high computational efficiency, short alignment time, and high alignment accuracy.