The Track Circuit Signal Simulator Dedicated For The Train Control System Hardware In The Loop Simulation

The track circuit is one of the outside important devices of railway signal, the key device which provides safety information to on-board device. The railway signal can monitor train operation, report the line occupation; transfer the control information, for example, the signals which have different frequency report the train’s location, control the semaphores, determine the operating speed and so on. Therefore, the reliability of signal directly affects the running safety and efficiency of train operation; testing and analyzing track circuit signal is one of methods by which we can protest the train safety.This paper researches a track circuit signal generator according to the characters of the jointless track circuit signal, which is used to simulate the field signal, to provide conditions in which cab signal system testing can be executed in the laboratory, and to make up deficiency in the existing testing methods.This thesis’s prime work is as follows:1. The demand analysis of track circuit signal simulatorThe functional demands and the other of hardware in the loop track circuit signal simulator is analyzed; the system architecture of the simulator is established; the necessity and significance of the track circuit signal simulator are elucidated.2. The characters analysis and modeling of the track circuit signalUsing the transmission line theory, establish the track circuit of four terminal network model. Based on above model, deduce the track circuit current signal’s envelope curve formula, and analyze the influence of ballast resistor, capacitor and the sending end voltage on the envelope curve; analyze the causes and characteristics of the unbalanced traction current; using the crosstalk knowledge, analyze the characteristics of adjacent track interference and same-line interference; finally, provide the track circuit signal model dedicated for the train control system hardware in the loop simulation.3. The system design of the simulatorAccording to the track circuit signal simulator’s needs analysis, build the hardware platform, introduce the working parameters and the testing method of each component in the hardware platform; using LabWindows/CVI design the software of track circuit signal simulator. According to the demand of track circuit signal simulator, using the modular design method, the software is divided into several modules:user interface, signal replaying, signal generation, sequence selection, interference function and so on. The difficulties in software realization are: how to make the interval between two track circuit signals shortest. How to realize CVI and Matlab mixed programming.4. The testing and application of the systemAccording to the software testing flow, the simulator is tested; the simulator is used in the on-board cab signal test to verify the accuracy of the signal.As test shows, the design conforms to theoretical analysis, and owns required precision.