Models Research And Performance Analysis Of GNSS/INS Integrated Navigation

As one of the most potential technique among all the navigation and positioning methods,GNSS/INS integrated navigation technique still cannot meet all the needs of users completely.In order to improve the accuracy of GNSS/INS integrated navigation system,this paper studied the GNSS/INS integrated navigation model and performances,which mainly includes the inertial sensor error model,the INS initial alignment technique,the GNSS/INS integrated navigation model and the GNSS/ INS integrated navigation model with additional constraints,etc.The main contents and research results are as follows:(1)The accuracy of INS initial alignment is directly related to the accuracy of the integrated system.Aimed at the initial alignment model of static base,sway base and moving base.The principle of coarse alignment and Kalman filter fine alignment is analyzed.On the basis of fine alignment,a static initial alignment model of forward and backward inertial navigation updating is proposed.The simulation and real data show that the method can effectively improve the initial Alignment accuracy.A polynomial fitting sway base initial alignment model based on REQUEST algorithm is proposed.The validity and reliability of the model are verified by simulation and real data.The initial alignment model of the moving base of GNSS aided INS and magnetometer aided INS is analyzed.(2)This paper studied the GNSS/INS integrated navigation model,analyzed the performance of loosely coupled model and tightly coupled model.Aimed at the problem of the poor positioning accuracy of GNSS/INS loosely coupled model and the traditional pseudo-range/pseudo-range rate tightly coupled model,this paper proposes an INS aided GNSS single-frequency single-epoch ambiguity fixed model based on tightly coupled.The experiments shows that INS aided single-frequency GNSS can effectively improve the ambiguity fixed rate,the positioning accuracy is improved.In the case of short-term satellite signal losing lock,the integrated system still has better positioning accuracy,ambiguity can be fixed quickly when satellite signal recovery.(3)To solve the integrated navigation system error divergence problem of satellite signal long-term losing lock,this paper studied the GNSS/INS integrated navigation model with additional constraint information.The static zero-speed constraint model,the dynamic zero-speed constraint model and the odometer-aided INS integrated navigation model were constructed,respectively.At the same time,the adaptive federated Kalman filter is improved.Experiments show that the accuracy and stability of the integrated navigation are improved.