Analysis And Research Of Unilateral Axle Counting Sensor Electromagnetic System

Axle counter is used to determine the clearance or occupation of a certainrailway section by detecting the train wheels.It is an important infrastructure toguarantee the railway transport safety and improve the railway operationalefficiency.At the present,compared with the abroad application of unilateral axlecounting sensor,the domestic application of bilateral axle counting sensor has theproblem of high cost, complex structure, difficult in installation andmaintenance.Therefore,the electromagnetic system as a core part of the unilateralaxle counting sensor are analysised and designed in this paper.The emulationalmodel of sensors,the distribution and variation of its magnetic field and the bestspace position relations of the parts in the electromagnetic system are given in thispaper.Analysis the principle of wheels counting,velocity and driving directiondetecting of the unilateral axle counting sensor,which provide theoretical basis forthe corresponding detection circuit design and development of axle sensors.First,this paper studies the structure of the unilateral axle counting sensor andhas designed the modified structure of the unilateral axle counting sensor on thebasis of the bilateral axle counting sensor. The Magnetic circuit model of the sensoris established and analyzes the working principle of the sensor.And the principle ofthe wheels counting signal is analyzed.Second,the electromagnetic system of the unilateral axle counting sensor isdesigned.The material,size,electrical parameters of the excitation coil and inductioncoil are designed.And the parameter information of the core in the excitation coiland the shell of the sensor are given in this paper.The circuit to generate theexcitation signal and the circuit to receive and amplify the induction signal aredesigned.Third,the magnetic field of the unilateral axle counting sensor is studied. The3d simulation model of the sensor is established and the distribution and variationrule of the magnetic field is analysised by finite element simulation software whenthere is a wheel or without a wheel on the sensor.Study the influence to theinduction electromotive force when the space positon between the excitation coiland the induction coil is changing.And the influence of wheel’s size and thefrequency of the excitation signal on the induction electromotive force is analyzed.Finally,we study the change rule of the induction electromotive force when awheel pass the sensor in dynamic process.Analysis the feasibility that use the staticsimulation of wheel at different positions to replace the dynamic processsimulation.And study the method to realize the function of wheels counting,velocity and driving direction detection of the unilateral axle counting sensor.Analysis theinduction electromotive force when the sensor is in failure.