CNS+GNSS+INS船载高精度实时定位定姿算法改进研究

天文导航(CNS)、卫星导航(GNSS)和惯性导航(INS) 3种系统组合可提供高精度的定位定姿结果。实际工程中因INS长时间误差累积,以及系统硬件传输存在不可忽略的时间延迟,导致INS提供给CNS的预报粗姿态误差较大,恶劣海况下难以保障快速搜星,造成天文导航可靠性下降、姿态测量精度较低的问题。为此,本文提出了一种CNS+GNSS+INS高精度信息融合实时定位定姿框架,引入了等角速度外推措施,有效地解决了惯导信息延迟问题。通过高精度转台模拟恶劣海况下载体大角速度摇摆,验证了本文提出的改进算法的有效性。试验结果表明,该算法架构简单,性能可靠,显著提高了恶劣环境下星敏感器的快速、准确搜星能力,保障了三组合姿态测量的精度和可用性。

Research on improvement of CNS+GNSS+INS ship-borne high precision real-time positioning and attitude determination algorithms

The celestial navigation system(CNS), global navigation satellite system (GNSS) and inertial navigation system (INS) can provide high precision positioning and attitude results. In practical engineering, because of the accumulation of INS long-time errors and the time delay that can not be neglected in the transmission of system hardware, INS provides CNS with a large prediction coarse attitude error, which makes it difficult to guarantee fast satellite search under bad sea conditions, resulting in the decline of the reliability of astronomical navigation and the low accuracy of attitude measurement. In this paper, a real-time positioning and attitude determination framework based on CNS+GNSS+INS high-precision information fusion is proposed. Extrapolating equal angular rate is introduced to solve the problem of inertial navigation information delay effectively. The experimental results show that the proposed algorithm is simple in structure and reliable in performance. It significantly improves the fast and accurate star-searching ability of star sensors in harsh environments, and ensures the accuracy and availability of the CNS+GNSS+INS integrated system's attitude measurement.