Optimization And Method Research Of Train Combination Speed Measurement And Positioning Technology

With the faster speed of high-speed railway and the rapid development of urban rail transit,the ever-increasing passenger flow and passenger security requirements have put forward higher requirements on Chinese Train Control System.Train speed measurement and positioning technology,as the key technology of Chinese Train Control System,undertakes the important responsibility of accurately measuring train speed and position information.Therefore,the research on velocity measurement positioning precision and safety zone setting is of great significance.Aiming at the current widespread problem of large errors in the speed measurement positioning system due to wheel idling and slippage,the research carried out in this paper is as follows:(1)The domestic and foreign research status of combined train speed measurement and positioning technology and Multi-sensor information fusion algorithm are reviewed.After analyzing the advantages and disadvantages of different train speed measurement and positioning methods,the measurement model and error model are established by combining the working principles of the wheel axle sensor,Doppler radar,accelerometer and transponder.(2)Diagnose the fault of each sensor,analyze the failure of the wheel axle idling slip as a special fault,and put forward a four-level slip diagnosis method based on the fixed threshold judgment method.The case analysis verifies its effectiveness.(3)The calculation method of train safe speed zone for different operational stages is designed,focusing on the braking and deceleration phases of trains where skidding may occur.The zone fusion method is used to fuse the safe speed zones of the wheel axle and the radar to obtain the safe speed zones.The calculation proves to be consistent SIL4(Safety Integrity Level)safety level is required,and the effect of the safety zone is shown through a graph.After that,the safe positioning interval of the train is obtained by integrating,and the positioning accuracy level is judged by the positioning error uncertainty.Finally,the accuracy of the proposed calculation method is verified through actual experiments.According to the sum of the uncertainty of the safe positioning interval,the error threshold is Internally verified compliance with SIL4 safety level requirements.(4)Two sets of plans for multi-sensor combined speed measurement are designed,standard Kalman filtering is used for information processing and state estimation,and three optimal information fusion algorithms under linear minimum variance are used to obtain information from the estimated results after the two plans are filtered.Fusion,design experiments to analyze the fusion effect,and finally determine the optimal fusion method and optimal fusion speed based on the comparison results.(5)Finally,based on the above methods and algorithms,a combined train speed measurement and positioning system based on UI(User Interface)design integrating fault diagnosis,speed fusion optimization,safe speed and position interval calculations.