Research On Resistance Monitoring System Of Railway Switch

Turnout is a kind of line connection device that makes the train transfer from one track to another.It is the weaker link of the track.The special structure of railway switch conversion system makes the force of conversion process very complicated.In the process of conversion switch,the system is affected by tensile pressure and bending moment.At the same time,the switch is affected by altitude,temperature and other environmental factors.In the long term,it will cause the deformation of the switch,resulting in abnormal conversion resistance,which seriously endangers the safety of the train.Monitoring switch resistance can detect anomalies in time,so real-time monitoring of switch resistance is of great significance.However,there are relatively few studies on switch resistance monitoring at present.In this thesis,a monitoring system for switch resistance is designed for real-time monitoring of switch resistance.In this thesis,the static simulation analysis is carried out on the switch conversion system to obtain the stress distribution of the switch system under the static action,and the optimal measuring point position is analyzed and found out.By setting different simulation forces,the simulation strain results of the optimal measuring point of each component under different forces are extracted to realize the virtual test of the conversion resistance.Considering the actual situation that the elastic body is still in the elastic stage under the action of the ultimate output force of 15 KN,the slender tie rod is selected as the main body of the sensor.By selecting the full bridge circuit with the highest sensitivity to compensate the micro strain caused by bending moment and temperature in the process of switch conversion,a set of bridge conditioning circuit composed of filter circuit,amplifier circuit,analog-to-digital conversion circuit,serial communication circuit,etc.,is designed to realize the resistance test,and offset the coupling effect caused by bending moment.The calibration platform was built,and the test scheme was developed according to the requirements of the current national standard "Verification Regulation of Force Sensor" JJG-391 2009.The calibration test of the sensor elastomer and system was completed.The least square method was used to fit the calibrated data,and 8 static performance indicators related to the sensor were obtained,which all met the national standards.The force measurement accuracy of this sensor is better than 0.5 class.The switch resistance monitoring system can realize real-time monitoring of switch resistance in the process of switch conversion and avoid the problem of stress concentration caused by the opening of force pin.It has great application value and development potential in the field of railway system monitoring.