基于SINS/GBAS组合导航的高精度进近着陆导航技术

可重复使用运载器在进近着陆阶段对位置偏差有较高的精度要求, 而现有的组合导航方式的导航误差波动幅度较大, 难以满足运载器在进近着陆段的导航要求。因此，本文利用捷联惯导系统(strap-down inertial navigation system，SINS)的非线性误差传播模型, 以陆基增强系统(ground based augmentation system，GBAS)输出的精确位置信息为基础, 建立SINS/GBAS组合导航方法, 并给出“输出+反馈”的组合导航复合修正结构。通过在GBAS中引入电离层误差及对流层误差, 从而实现了对于运载器定位误差在厘米级的精确定位。此外，通过引入扩展卡尔曼滤波技术, 有效地抑制了惯导误差漂移的问题。通过数值模拟仿真, 证明SINS/GBAS组合导航对飞行器进近着陆段的水平与高程定位误差不大于0.05 m, 测速误差不大于0.05 m/s, 从而证实了SINS/GBAS组合导航方式在可重复运载器在进近着陆段导航的可行性。

High precision approach-and-landing navigation technology based on SINS/GBAS integrated navigation

Reusable launch vehicles have high accuracy requirements for position deviation during the approach-and-landing phase. However, the existed combined navigation methods have a large fluctuation of the navigation error, which cannot meet the navigation requirements of the launch vehicle in the landing approach section. In this paper, we establish a combined navigation method based on the precise position information output form the ground based augmentation system (GBAS) and the nonlinear error propagation model of the combined navigation strap-down inertial navigation system (SINS). We provide a composite correction structure of "output+feedback" for the launch vehicle navigation based on SINS/GBAS combined navigation. By introducing ionospheric and tropospheric errors into GBAS, the precise positioning of the vehicle positioning errors at the centimeter scale is achieved and the inertial guidance error drift problem is effectively suppressed by the extended Kalman filter algorithm. The simulation results show that the horizontal and elevation positioning error of the combined SINS/GBAS navigation is no more than 0.05 m; the velocity error is no more than 0.05 m/s. We verify the feasibility of the combined SINS/GBAS approach for the vehicle approach-and-landing navigation system.