Research On SINS/GPS Intergrated Navigation System And Filtering Algorithm Involved

The Strapdown Inertial Navigation System(SINS) bears the features of autonomous navigation and high maneuverability, however, the divergence phenomennon of the navigation output will occur due to error accumulation during a long time navigation. The Global Positioning System(GPS) can provide the continuous navigation information with high accuracy, but the signal failure may occur to the GPS since it is quite vulnerable to external interference. In this case, the SINS/GPS integrated navigation system, which is the combination of the above two systems, has made some improvements in their respective subsystem. The SINS/GPS integrated navigation system has a good navigation performance and now it has become a main form of navigation technology.The SINS/GPS integrated navigation system and the filtering algorithm involved are researched by this paper. Based on a detailed theoretic analysis of SINS, the paper focuses on the research of the the linear approximation models and the non-linear model from different initial attitude error angles, and then the error equations of the two models are established separately.Secondly, the paper establishes linear state equation and nonlinear state equation of SINS models in loose integration mode and the same measurement equation is applied in these two models. Then the paper focuses the analysis on Kalman Filter(KF) in linear model, also Extended Kalman Filter(EKF) and Kalman Filter(SPKF) in non-linear model based on the Sigma Points. The simulation calculation of these filtering algorithms is performed under corresponding system model and the results are analyzed.The navigation output accuracy of SINS / GPS integrated navigation system will decline when GPS is not available. Zero Velocity Update(ZUPT) technology is used for the error correction in this paper. As a relevant algorithm, the zero velocity detection algorithm is applied in the carrier movement. This mothed has achieved an integrated navigation system filtering algorithm based on ZUPT. The simulation shows that the algorithm effectively improves the accuracy of navigation by limits the velocity value of GPS in zero-velocity condition.Finally, we makes field trials of the ZUPT-based integrated navigation algorithm on the MEMS experimental platform. The result is compared with that of the simulation and it is proved that the algorithm is valid. The test confirms that the proposed algorithm can improve the accuracy of the integrated navigation system regarding engineering implementation.