舰载捷联惯导姿态更新算法研究

Algorithm of Updating Attitudes for Shipborne Strap-Down Inertial Navigation System

针对舰艇、轮船等经常处于低频圆锥运动、角机动等恶劣工作环境,传统姿态更新的误差补偿方法在多子样更新中补偿效果较差的问题,提出了一种改进方法。通过建立角增量的2N-2阶近似模型并利用其各阶导数之间的解析关系,实现了对等效旋转矢量的进一步修正。使用参数解析法与改进算法分别推导研究了四子样情况下的优化结果,并分析研究了改进算法在四子样以上情况下的适用性。研究表明,与参数解析法相比,改进算法可以在四子样及四子样以上的情况下简单直观地得到更加精准的优化系数,且与四子样参数解析法相比,其误差缩小了2个数量级,同时也比五子样参数解析法更精确。

Ship navigating at sea often has to operate under critical sea conditions,and it will result in low-frequency cone motion or angular motion.The common method of error compensation for updating attitudes of shipborne strap-down inertial navigation system are less effective when applied to manage multiple sub-samples.An improved method was then presented,which was to build a mathematical model of angle increment of 2N-2 order and utilized the analytical relationships among derivatives to further revise rotation vector.The optimal results of four sub-samples were derived by the parametric analytical method and the improved algorithm respectively,the applicability of these methods for the sub-sample greater than four was also investigated,it was found that using the improved algorithm can get a more accurate optimization factor for the four or more sub-samples in comparison with the parametric analytical method,enabling two orders of magnitude reduction in errors lower than with the analytical method of four sub-samples and get precision higher than with the analytical method of five sub-samples.