一种GPS/INS组合导航缺星情况下的方法研究

Method to GPS/INS Integrated Navigation Under Condition of GPS Signal Invalidation

为了提高GPS/INS组合导航系统在卫星信号缺失情况下的导航精度,采用基于伪距、伪距率的非线性紧组合模型,利用虚拟卫星法构造虚拟观测量,与真实观测量一起参与滤波。针对非线性滤波应用中的问题,采用强跟踪滤波原理和均方根策略对CKF进行改进。通过仿真实验,验证了改进算法和虚拟卫星法的可行性,在卫星信号缺失情况下可以提高导航精度,提高了组合导航适应复杂环境的能力。

In order to improve the navigation accuracy of GPS/1NS integrated navigation system under the condition of GPS signal invalidation, tightly-coupled model based on pseudo-range and pseudo-range rate was adopted, virtual observation using the method of virtual satellite was constructed and participated in filtering with real observation. For the problem in the application of nonlinear filtering, the theory of strong tracking filter and RMS strategies were used to improve the CKF. Simulation results verify the feasibility of improved algorithm and the method of virtual satellite, the navigation accuracy can be improved under the condition of GPS signal invalidation and the ability of GPS/INS integrated navigation to adapt to the complex environment are also improved.