基于矢量跟踪的SINS/GPS深组合导航方法

Deeply SINS/GPS integrated navigation method based on vector tracking

为了满足高动态用户及强噪声干扰条件下的应用需求,提出了一种基于矢量跟踪的SINS/GPS深组合导航方案。深组合方案利用组合卡尔曼滤波器反馈回路取代了传统接收机中独立、并行的跟踪环路,能够同时完成所有可视卫星信号跟踪和组合导航信息处理的任务;利用相关器残差来更新导航参数状态,同时根据已有的导航参数和星历信息推测GPS伪码相位和多普勒频移等信号跟踪参数,用以控制接收机的本地伪码、载波数控振荡器(NCO),使本地伪码相位和载波频率与输入信号保持一致。最后,通过仿真验证表明,基于矢量跟踪的深组合方法不仅在GPS信号发生短暂中断期间,能够保证组合系统的导航精度和可靠性,而且在载噪比较低的环境中能够维持较好的伪码相位和载波频率跟踪性能。

To satisfy the application requirements of GPS receivers under high vehicle dynamics as well as severe noise jamming conditions, a deeply integrated navigation scheme of Strapdown Inertial Navigation System/Global Positioning System （SINS/GPS） based on vector tracking is proposed. The deep integration scheme utilizes the feedback loop of integrated Kalman filter to replace the independent and parallel tracking loops in traditional receivers, which enables GPS receivers accomplish the tasks of available GPS satellite signals tracking and integrated navigation information processing synchronously. The outputs of correlator are used to update the navigation parameters. Meanwhile, the signal parameters such as pseudo random noise （PRN） code phase and Doppler frequency are derived from the known navigation parameters and broadcast ephemeris, and used to control the local PRN code and carrier numerically controlled oscillator （NCO）. Consequently, the referenced code phase and carrier frequency could keep consistent with the corresponding inputting GPS signals. Finally, the simulation results indicate that this deep integration scheme could not only guarantee the navigation precision and reliability of the integrated system during brief signal outage, but also maintain perfect tracking performance of code and carrier frequency at low carrier-to-noise power density ratio （C/N0） level.