Research On High Precision Positioning And Orientation Technology Based On Multi-source Information Fusion

With the development of rail transit,the traditional navigation method has been unable to meet the requireme nts of the navigation systems for trains in complex environments.In the case of satellite navigation failure under extreme conditions,a multi-source information fusion integrated navigation algorithm based on strapdown inertial navigation system is established in this paper.The main contents are as follows:First,the inertial/velocimeter combined navigation algorithm.Considering the installation error of the inertial device relative to the vehicles,the scale factor error of the laser doppler velocimeter,the arm error of the laser Doppler velocimeter relative to the inertial navigation,the error model and the measurement equation of the inertial/velocimeter integrated navigation are derived.Simulation verification and dynamic vehicle tests are carried out on the inertial/ velocimeter integrated navigation algorithm.Second,positioning and speeding algorithms relying on image matching.The artificial marker is placed beside the route,the position of the current time is obtained by the high-speed camera identification marker,the velocity of the train is calculated according to the relative position change of the two consecutive frames.The inertia/image matching integrated navigation algorithm is simulated to analyze the feasibility of the inertia/velocimeter/image matching integrated navigation algorithms to replace the inertial/satellite integrated navigation al gorithms in the case of satellite navigation failure.Third,the federated filter algorithm.The inertial/satellite/velocimeter integrated navigation algorithm based on federated filter is simulated,and the federated filter adopts the highest fault-tolerant structure.The simulation satellite navigation and velocimeter malfunction,analyze the reliability of the fault detection and isolation algorithm.Simulation and vehicle experiments can prove that without satellite navigation,rail transit can still obtain high-precision attitude and position information using multi-source information fusion integrated navigation system.