惯性系姿态确定的SINS晃动基座初始对准算法

Alignment Algorithm Based on Attitude Determination in Inertial Frame for SINS with Swaying Base

在晃动基座下,载体将受到外界干扰(例如阵风和海浪),从而使传统解析粗对准无法完成捷联惯导系统(SINS)初始对准过程。基于此,采用SINS惯性系姿态确定初始对准算法解决SINS晃动基座初始对准,并使用Davenport-q递归算法实现其姿态确定过程。传统惯性系初始对准算法直接采用构造重力矢量观测来实现初始对准过程,可能会引起矢量构造共线,从而造成初始对准过程姿态计算震荡,降低其对准性能。通过分析晃动基座初始对准实际条件,提出了采用构造速度矢量观测来实现其对准过程,可以充分利用积分平滑作用,抑制周期性噪声和高斯白噪声,从而可以提高其对准性能。最后,通过SINS某码头系泊状态的对比测试试验进行验证,采用速度观测矢量完成SINS姿态确定初始对准时,其误差曲线将更加平滑,并具有优越的性能。

As on the swaying base, the vehicle would always withstand the external disturbance,such as gust and sea wave, it would be difficult to implement the initial alignment of strapdown inertial navigation system(SINS) by the traditional analytical coarse alignment. In this paper, the SINS attitude determination in inertial frame is applied to initial alignment with swaying base. And the Davenport-q recursive algorithm is used to implement the SINS attitude determination. For the traditional attitude-determination alignment algorithm, the construction of gravity vector observation is usually used to achieve the initial alignment process, which may cause the vector construction collinearity, thus resulting in the attitude calculation oscillation in the initial alignment process and reducing its alignment performance. By analyzing the actual conditions of the swaying base, the construction of velocity vector observation is proposed for initial alignment. As a result, the smoothing effect of integration can be utilized to suppress the periodic noise and the Gaussian noise, and thereby improve the alignment performance. Finally, the SINS contrast experiments of mooring at some lake are carried out to demonstrate the performance. The test results show the superior performance and the smoother error curve with the velocity observation.