Research On Integrated Navigation Technology Based On Kalman Filter

A single navigation system is limited by hardware performance,which makes it difficult to meet the demand of high-precision positioning for high-speed motion carriers.Combining the optimal estimation method of Kalman filter with the integrated navigation system,the advantages of a single navigation system can be taken,therefore,the positioning precision,stability and reliability can be improved.The thesis mainly focuses on the integration of the two system,Inertial Navigation System(INS)and Global Positioning System(GPS)integrated navigation system.The thesis analyzes the performance of Kalman filter algorithm in integrated navigation system,designs an optimized Kalman filter algorithm and it is applied to loosely coupled and tightly coupled of integrated navigation system simulation experiment.The main research contents are as follows:Firstly,the working principle,the navigating solution method and the error source of INS/GPS integrated navigation system are analyzed respectively and the error models are established corresponding to different error sources.For Inertial Navigation System,the propagation characteristics of position error,speed error and attitude error in low-speed and high-speed carrier motion are analyzed respectively.At the same time,for Global Positioning System,the error in high-speed carrier motion are analyzed,which lays the foundation for the design of INS/GPS integrated navigation system.Secondly,the Kalman filter algorithm in the integrated navigation system is studied in depth,and the theoretical formula is derived in detail.In order to reduce the effect of random errors,which cannot be eliminated in the integrated navigation system,on the performance of the algorithm,the optimized Kalman filter algorithm is designed.The time-related random errors are modeled separately,the error covariance matrix and gain matrix of Kalman filter algorithm are modified,thus the precision and stability of the integrated navigation are improved.The feasibility of the optimized Kalman filter algorithm is verified by the INS/GPS integrated navigation simulation.Compared with the unoptimized algorithm,the integrated navigation has faster error convergence and better stability in the optimized algorithm.Finally,the coupled method of integrated navigation is studied,the loosely coupled model and the tightly coupled model are established.Loosely coupled and tightly coupled integrated navigation in high-speed carrier motion are simulated.By comparing the simulation results,it is shown that: when the carrier is moving at the high speed,the speed and position errors of tightly coupled navigation converge faster,and the stability and positioning precision are higher.Tightly coupled navigation is more suitable for positioning of high-speed motion carriers.In the simulation experiment of INS/GPS integrated navigation system,the Kalman filter algorithm and the coupled method are both feasible and effective.It lays the foundation for further research on INS/GPS integrated navigation system in the future.