Research On Wheel Set State Detection System Of Urban Rail Train

The wheelset,which is a key running component,has a crucial influence on the safe operation and riding experience of urban rail vehicles.The health status of the wheelset is related to the safety of the passengers.Besides,Its good running state can reduce the vibration and noise caused by the bad state of wheelset,and provide a more comfortable riding environment and a better riding experience for passengers.The wheels are always in a state of wear due to the friction from the rails when the train is running.If they cannot be detected and evaluated in time,it will cause a great potential safety hazard to the train operation.There are two methods to inspect wheel in domestic metro.Firstly,the operator uses the measuring ruler to detect the vehicle after it is put into the warehouse.In this method,the labor intensity of the worker is large,and the vehicle turnaround time is long.Secondly,CCD camera image processing is used for detection.However,this method requires complex equipment,difficult installation and a high overall cost.In this paper,a laser displacement sensor based measurement system of wheel key geometric parameters and wheel tread state detection system are designed.The system has the advantages of low cost,simple installation and dynamic detection of wheel set state.The specific work of this paper includes:The detection system based on single laser displacement sensor is studied.It is found that the positioning error of the lowest point of the wheel will cause great error to the measurement result of the whole wheel diameter,which cannot meet the detection of urban rail vehicles in the field.On this basis,a dynamic measurement system of wheel diameter based on double laser displacement sensor and eddy current sensor is designed.The system uses eddy current sensor to locate the lowest point of the wheel accurately,and two other positions of the wheel are determined by two laser displacement sensors.The diameter of the wheel can be calculated by three-point positioning method.Through the analysis of the system error,the wheel diameter measurement error is 0.48 mm,which can meet the field measurement needs of the railway department.A laser displacement sensor system is designed.According to the laser triangulation method,the measurement system of wheel flange thickness,rim width and inner distance of wheel set are completed,besides,the system error is analyzed.The wheel tread state detection system is designed.In theory,the running state of standard wheel,scraped wheel,evenly worn wheel and out of round worn wheel on the rail is analyzed to understand its motion mechanism.On the basis of that,the inspection system of parallelogram mechanism is upgraded and reformed.The running state of wheel tread can be reflected by using the feature that the top of wheel flange is not easy to be worn and the displacement change in the vertical direction of the measuring rod in the system,besides,the inspection of wheel tread wear degree,scratch length and depth,and radial runout can be realized.The overall software design of the wheel set detection system of urban rail train is completed,and the module design of the wheel set diameter measurement system,the wheel flange thickness and rim width and inner distance measurement system,and the wheel tread detection system are also carried out.The software includes noise reduction processing,curve fitting,result calculation and other modules,which can implemented the train wheel set state detection function.The accuracy of the system can be verified in the subway field,which can meet the needs of field detection.