船用星敏感器/光纤惯性测量单元深耦合导航方法研究

Inertial navigation equipment is the core part of ship navigation system，but its error accumulates over time. Thus it can not guarantee high accuracy in a long period. Celestial navigation equipment has the advantage of high accuracy and ulterior property, and its error doesn't accumulate with time. But its applicability is limited by the ability of measuring star. Also its structure is complicated and the reliability is low. To improve the long time accuracy and all-weather applicability of ship navigation, a marine strapdown inertial navigation (SINS)/astronomical integrated navigation system which composed of star sensor and fiber-optic gyroscope (FOG) inertial measurement unit (IMU) is proposed in this project. The integrated navigation system has advantages of small volume, low cost and high reliability. Tightly coupled framework is setup for the integrated navigation system firstly. The attitude of ship with respect to inertial coordinate will be calculated based on FOG IMU. The dynamic error of star sensor will be compensated based on ship's real time attitude information. Research of nonlinear filtering algorithms for tightly coupled integrated navigation system will also be performed. Finally, experiment will be designed based on FOG IMU developed by ourselves and three axis test turntable device to confirm the efficiency of the proposed method and key technologies. This project will set up a solid foundation for the application of SINS/astronomical integrated navigation system and push forward the development of ship navigation technologies.

惯性导航设备是舰船特别是战斗舰艇导航系统的核心，但由于导航信息误差随时间积累，很难满足长航时需求；天文导航设备具有误差不随时间积累、隐蔽性好等优点，但由于测星能力差、结构复杂、可靠性低等众多问题导致其无法大范围应用于船用领域。为弥补上述各导航设备的不足，满足舰船对导航系统全天候、长航时的应用需求，本项目提出一种由星敏感器与光纤惯性测量单元构成的小体积、低成本、高可靠性船用捷联式天文/惯性导航系统方案，建立深耦合导航总体框架；针对光纤惯性测量单元相对惯性空间的姿态解算方法、基于舰船实时姿态信息的星敏感器动态测量误差修正方法和星敏感器/光纤惯性测量单元深耦合非线性滤波算法等核心关键问题开展了研究工作；以自研的光纤惯性测量单元为基础辅以高精度三轴测试转台等设备构建半实物仿真测试环境，对本课题的研究内容及各项关键技术进行验证，为该方案的实际应用奠定基础，进而推动舰船导航技术的发展。

惯性导航设备是舰船特别是战斗舰艇导航系统的核心，但由于导航信息误差随时间积累，很难满足长航时需求；天文导航设备具有误差不随时间积累、隐蔽性好等优点，但由于测星能力差、结构复杂、可靠性低等众多问题导致其无法大范围应用于船用领域。为弥补上述各导航设备的不足，满足舰船对导航系统全天候、长航时的应用需求。本项目建立深耦合导航总体框架，对惯性测量单元和星敏感器输出的导航信息进行数据融合，从而提高系统导航精度；针对星敏感器定位需要外部提供水平姿态基准这一问题，提出一种基于惯性系重力特性的水平基准确定方法；针对舰船在摇摆状态下，星点光斑在像平面上发生像移，进而会降低星敏感器的姿态测量精度的问题，对光纤惯性测量单元和星敏感器进行深度耦合，以达到修正星敏感器动态测量误差目的；利用项目组研制的光纤惯性测量单元与星敏感器搭建船用星敏感器/光纤惯性测量单元深度耦合导航系统，对本课题所涉及的算法进行验证。