| As an important part of the station interlocking system,the track circuit in the station plays a vital role in the safety of the train and the improvement of the efficiency of the train.But system parameters are larger affected by the climate condition outside,the external electromagnetic field and other complex environment,especially poor shunt of the track circuit,and gives rise to higher rail shunt voltage,brings great inconvenience to the people who manages and takes a maintenance of the electricity and traffic,can even cause the loss of the footprint of the train,and takes a happen of an accident,impacts on the train operation safety seriously.Therefore,the research on the bad shunt of track circuit in the industry has never been interrupted with the development of track circuit.For the currently vigorously developed high-speed railways,both the main line and the strands of the station adopt the integrated track circuit system.The existing solutions mostly use the physical method of coating and regular polishing,which consumes huge manpower and material resources,is inefficient,and cannot Solve the problem permanently.The frequency shift pulse track circuit system is a new idea to improve the problem of poor shunting of integrated track circuits in the station.It is to mix the pulse signal into the frequency shift signal to effectively penetrate the rust layer of the steel rail,provide a channel for the transmission of the frequency shift signal,and ensure the reliable realization of the train occupancy inspection function of the track circuit.Therefore,it is of great research significance to develop an automatic voltage-regulating frequency-shift pulse track circuit to achieve dynamic management that improves the effect of track circuit shunting.The research content of thesis or dissertation article mainly includes the following parts:(1)based on the system structure and working principle of the frequency-shifted pulse track circuit,the main factors,mechanisms and causes of the poor track circuit shunt are summarized and analyzed qualitatively and quantitatively.At the same time,t he transmission characteristics of the asymmetric pulse signal are analyzed to establish an equivalent four-terminal network model to complete the characteristic parameter analysis of the track circuit section,and to provide a basic mathematical model for realizing the automatic adjustment of the pulse signal amplitude.(2)according to the transmission characteristics of the track circuit,the technical requirements for the normal operation of the on-board equipment,the basic adjustment requirements of the track circuit and the system function requirements,a mathematical model of the frequency shift pulse track circuit from the power transmitting end to the power receiving end is built.By establishing the corresponding relationship between the voltage and current of the power transmitting and receiving terminals,it provides a mathematical foundation for the fuzzy condition control in the subsequent chapters.Design frequency shift transmission circuit,pulse transmission circuit and frequency shift pulse isolation circuit to realize the stable operation of the system after the frequency shift signal and the pulse signal are superimposed.(3)make full use of the fuzzy control theory,take the pulse voltage at the receiving end of the adjustment state,the outdoor temperature,humidity and the frequency of train passing as input parameters,and use the graded branch characteristics as the output condition to establish the influence track.Input and output fuzzy control model of circuit shunt characteristics.Using actual empirical data,fuzzy control rules are established between input and output,and the center of gravity method is selected for anti-fuzzy operation,which achieves a more accurate corresponding relationship between input conditions and output conditions.The simulation results show that it is feasible to control the pulse sending voltage under multiple targets. |
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