组合导航中全球定位系统输出延迟补偿方法

Compensation Method for GPS Delay in INS/GPS Integrated Navigation

针对高速高动态飞行环境下全球定位系统(GPS)导航信息输出存在延迟,进而影响惯性导航系统/全球定位系统(INS/GPS)组合导航精度的问题,提出GPS输出延迟补偿的两种方法:状态递推补偿法和曲线拟合补偿法。状态递推补偿法利用卡尔曼滤波状态递推,将GPS当前输出与对应过去时刻惯导输出进行组合导航的结果递推更新到当前时刻,以获得当前时刻的组合导航结果;曲线拟合补偿法采用曲线函数来描述GPS的输出,利用延迟时间与曲线函数计算获得当前时刻的真实输出。仿真实验表明,状态递推补偿法的补偿精度较高,但必须依赖惯导输出信息,而且计算机存储负担重;曲线拟合补偿法算法简单、计算量小,不依赖于其他导航设备就能对GPS进行延迟补偿,工程易于实现。

Under high-speed and high-dynamic flight environment,global positioning system （GPS）delay will influence the precision of inertial navigation system/global positioning system （INS/GPS）integrated navigation. Two kinds of compensation methods for GPS delay were researched in this paper,they were compensation meth-od by state propagating and compensation method by parabola fitting.State propagating of Kalman filter was used to achieve the integrated navigation result at present by propagating the integrated navigation result in the past,which was achieved by GPS present output and INS past output.The parabola function was used to de-scribe GPS output in the compensation method by parabola fitting,and then the real output at present was calcu-lated by the delay time and the parabola function.Simulation experiments show that,the compensation method by state propagating has higher precision,but it depends on INS output and large memory.The algorithm of the compensation method by parabola fitting is simpler and small computing,which could be used to compensate GPS delay without navigation equipments and be realized easily in engineering application.