Research On The Key Technology Of Anti-spoofing In GNSS/INS Integrated Navigation

With the continuous development of IT-based warfare,the future battlefield will be a fast-changing,complex and uncertain environment,and the future military struggle will also face a greater unpredictable risk.The unmanned systems technology has unique advantages in the aspects of maneuverability,rapidity,persistence,reducing the risk of life,Etc.The intensive study of key technology of anti-spoofing in GNSS/INS integrated navigation is carried out under the unmanned systems environment,focusing on that satellite navigation terminals are vulnerable to outside interference,from the perspective of spoofing.Main contents and innovations are as follows:1.In accordance with the principles and characteristics of spoofing,anti-spoofing integrated filter algorithm based on sequential filter is studied based on tightly coupled system model.On this basis,from the perspective of Information compensation,an improved method is studied by introducing a fading factor filter theory.Simulation results show that two algorithms can effectively detect and eliminate interference,and the navigation precision still can meet the positioning requirements.compared to the former,the anti-spoofing effect of improved algorithm is more pronounced,because the improved algorithm can repair damage of accuracy to a certain extent caused by that the interference satellites are completely removed.2.In accordance with the principles of anti-spoofing integrated filter algorithm based on sequential filter,the three-section weighting anti-spoofing integrated filter algorithm based on sequential filter is studied by introducing an idea of subsection on the observation residuals.Simulation results show that compared to the robust estimation filter which builds expansion factor using single-factor variance expansion method,the improved algorithm has greatly improved navigation accuracy,and the anti-spoofing effect is more pronounced,increasing the treatment of the rejection area and taking account of the treatment of the acceptance and suspect area.3.Anti-spoofing GNSS/INS integrated synthetical filter algorithm is studied by combining the characteristics of the former two improved algorithm.Simulation results show that the accuracy of navigation system basically can recover to the accuracy without interference through this synthetical filter under strong interference environment,so the anti-spoofing effect of this synthetical filter is pronounced.4.Co-design of Software and Hardware for GNSS/INS Integrated Navigation System is carried out.First,from the perspective of minimizing the size,reducing power consumption and improving real-time performance,the dual-CPU overall scheme of integrated navigation system is designed.Then,based on the fully customizable Zynq-7000 platform,the hardware environment of integrated navigation system is builded.Based on the multi-task scheduling principle of uC/OS-III RTOS,the paper designs multi-task,task priorities and intertask synchronization mechanism reasonably.Based on the analysis of data exchange in integrated navigation filter,intertask communication is realized through setting the message queue,and the problem of “deadlock” is avoided with ensuring data consistency.The results show that the system can output higher accuracy results of integrated navigation,and each function module of the system works efficiently and reliably.The system as a preliminary study,laid the foundation of hardware and software platform for the engineering implementation of GNSS/INS Tightly coupled anti-spoofing system.