The Research Of Train Positioning Information Fusion Technology Based On GNSS

With the rapid development of China's high-speed railway,the traditional train positioning method can not meet the current operational requirements.At the same time,the train control system based on mobile communication urgently needs a new type of low-cost train positioning system.With the opening of the Qinghai-Tibet line in our country,the train positioning technology based on the satellite navigation system gradually enters our field of vision,and more and more people are beginning to study the train positioning technology based on the satellite navigation system.Therefore,GNSS-based train positioning technology can improve the transportation efficiency,reduce the operation and maintenance costs,is the future development of train positioning technology.In this study,GNSS-based train location information fusion technology is studied.The methods of GNSS-based fast high-precision location method,GNSS-based dual-difference attitude determination track occupancy method and GNSS-based train location signal integrity improvement method are studied..Specific research content and innovation as follows:1.A fast and high-precision positioning method based on GNSS is proposed.The problem of train rapid positioning based on satellite navigation system is solved by introducing the Doppler shift of train motion.On the other hand,how to connect the data of SINS/DR(SINS/DR)when satellite positioning data is interrupted,A high precision and seamless positioning method of GPS/SINS/DR train based on LS-KF algorithm is proposed.2.for the interval train track occupancy discrimination problem.A new method to determine the occupancy of train tracks based on GNSS double-difference attitude is proposed.A mathematical model of GNSS double difference attitude is established.Based on obtaining the baseline heading angle of train,a risk-sensitive filtering algorithm based on particle filter is proposed.At the same time,a classification algorithm based on SVM is proposed.Positioning data classification to determine track occupancy.Finally,the influence of the number of visible satellites and HDOP values on orbit occupancy determination is further studied.3.Aiming at the problem of the integrity of train positioning signals based on GNSS,a method to improve the integrity of satellite signals based on satellite orbital database and D-S evidence theory is proposed.By establishing a satellite orbit database to predict the number of satellites in front of the train and improve the signal integrity,the D-S evidence theory was used to improve the satellite pre-warning security of the train by establishing mathematical models based on available satellites,HDOP and pseudoranges.Finally,this paper tests the train locating system independently developed through the simulation test,vehicle(motor vehicle)movement test,Changsha magnetic levitation field test,proves the reliability and effectiveness of the method proposed in this paper,for GNSS-based train locating technology research Provide a certain reference value.