Research On Integrity Monitoring Method Of Satellite-based Train Positioning Aided By Trackside Augmentation Network

The application of Global Navigation Satellite System(GNSS)in train autonomous positioning is one of the important research directions of train operation control system.The positioning technology and electronic communication technology based on the global navigation satellite system will be used in the subsequent train control system.Among them,the acquisition of real-time position and speed is one of the key technologies of the train control system.In order to meet the requirements of higher accuracy and integrity in terms of precise positioning and speed measurement of trains,the research on the trackside augmentation network has been put on the agenda.The augmented information provided by the trackside augmentation network can be used to improve the accuracy of train satellite positioning,but there may be deviations due to the information transmission environment and the base station receiver itself,so that the location of the train receiving the augmented information also has a higher accuracy.Therefore,it is necessary to study the integrity monitoring of the trackside augmentation network itself and train positioning.Considering the safety requirements of train positioning,this paper proposes a method for monitoring the integrity of the trackside augmentation network to ensure that the enhanced data with high integrity is provided to the train.The redundancy of the navigation information received by the train is used to enhance the network on the trackside.With the auxiliary information provided,the integrity monitoring of the satellite navigation and positioning of the train is further realized,so as to meet some scenarios that require strict confidence intervals.The main work completed in the thesis includes:(1)The status quo of the integrity monitoring of enhanced networks and the integrity monitoring of auxiliary trains and the latest research results of the reference station network are summarized,and the basic principles and fault sources of satellite navigation and positioning and differential positioning are analyzed.(2)A two-layer trackside augmentation network integrity monitoring method is proposed,which uses the inter-station double-satellite double-difference of the pseudorange residual received by the reference base station as the statistical detection quantity,and uses the advantages of the two-layer monitoring method to realize the detection of faulty satellites.The detection and elimination of fault reference base stations,and the fitting and optimization of thresholds improve the detection level of faults.(3)A train positioning integrity monitoring method with the aid of the trackside augmentation network is proposed.The trackside augmentation network is used to predict the error of the train positioning result after receiving the differential information,and the level of protection level of the positioning result is solved to determine the integrity monitoring method.Availability,and then construct a weight matrix to implement a weighted least squares residual integrity monitoring method.In order to verify the feasibility of the proposed integrity monitoring method,the paper builds a fixed reference station network and conducts actual measurement and simulation experiments to collect data and inject simulated faults.After the simulation experiment of various faults injected and fitted,it is proved that the monitoring algorithm of the trackside augmentation network can effectively detect and eliminate different types of faults,and can also eliminate the faults that occur together,and verify the detection performance.It is verified that the train can achieve high-performance integrity monitoring with enhanced network assistance information at the trackside.The research results of this paper can enable the trackside augmentation network to better support the accuracy and integrity performance of the train,realize the accurate and reliable positioning of the train in various scenarios,and can also apply the results to other services that require enhanced services field.There are 33 pictures,9 tables,50 references.