SINS辅助GPS跟踪环误差分析与最优带宽设计

Error analysis and optimal bandwidth design for SINS-aided GPS tracking loop

SINS(Strapdown Inertial Navigation System)辅助GPS(Global Positioning Sys-tem)跟踪环路的结构设计是SINS/GPS超紧组合系统实现的主要环节,而环路带宽是决定不同误差源作用下GPS跟踪环路性能的关键.首先对SINS/GPS超紧组合系统中影响载波锁相环(PLL,Phase Lock Loop)跟踪性能的各误差源进行了详细的建模与分析,进而设计了一种最优环路带宽的调节方法.该方法基于最小化跟踪误差的准则,根据接收机检测到的信号载噪比实时调节PLL带宽,以使环路保持最优跟踪状态.结果表明,所设计的最优环路带宽调节方法能够有效提高SINS辅助PLL的抗干扰性能与跟踪精度.

Design of the strapdown inertial navigation system （SINS） aided global positioning system （GPS） tracking loop is the primary process in the realization of the SINS/GPS ultra-tight integration system, and the loop bandwidth selection is the key to balance the performance of tracking loop under different error sources. Firstly, the error sources affecting the tracking performance of the phase lock loop （PLL） were mod- eled and analyzed. Then, on the principle of minimizing the tracking error of the SINS-aided PLL, an optimal adjustment method of the loop bandwidth according to the carrier-to-noise ratio detected by GPS receiver was proposed to keep PLL in optimal tracking state. Analysis results show that this method can effectively improve the anti-jamming performance as well as the tracking accuracy of the SINS-aided PLL.