惯性速度辅助下GPS／捷联惯导组合系统性能研究

Research on Performance of Inertial Velocity Aiding GPS/SINS Integration System

ＧＰＳ／惯性导航组合系统目前正得到越来越广泛的应用，但ＧＰＳ接收机载波环失锁时，码环的速率辅助信息来自惯导系统。由于惯性速度的不精确性及伪距测量误差和它之间的相关性，将可能导致组合系统工作的不稳定。本文根据码环的工作特性，在组合系统卡尔曼滤波器中考虑了码环的跟踪误差，利用ＧＰＳ星座仿真器实时选择最佳导航星，用协方差法分析了飞机机动飞行时ＧＰＳ／捷联惯导组合系统的导航性能。结果表明，ＧＰＳ／捷联惯导组合系统中，若消除了伪距测量误差与惯性速度误差之间的相关性，将可较显著地提高导航系统的导航精度，并保证了码环处于跟踪状态，使组合系统能正常稳定地工作。

GPS/INS integration systems are widely used in different fields. Since GPS receiver carrier loop has lost lock during maneuver,the velocity aiding signal of code loop is derived from the inertial navigation system. Because of the correlation between the pseudorange measurement error and the inertial velocity etror,it will make the integration system operation instable. On the basis of GPS receiver code loop operation characteristics, the code loop tracking error is considered in the Kalman filter.Optimal navigation satellites are selected in real time by a GPS simulator. The navigation performance of a GPS/SINS integration system is analyzed during the airplane maneuver.The simulation results show that the code loop operates in the tracking state,the integration system operates normally and stably,and the navigation accuracy of the system is evidently improved when the correlanon between the pseudo-range measurement error and the inertial velocity error is eliminated.