Research Of Icing Status Sensor For High-speed EMU Train

The High-speed EMU trains(High-speed EMU Trains),which are characterized by safety,punctuality,and quickness,are increasingly favored by passengers and have become the preferred mode of transportation for people traveling in recent years.However,in some areas of northern China,in the winter,especially after rain and snow,high-speed trains can easily cause bogies and brake calipers to freeze during operation.In severe cases,they can even cause train steering difficulties and brake failures.Besides thick ice blocks tend to fall off and the impact force generated by a small piece of shedding ice is enough to cause damage to the vehicle piping equipment when the train is running at high speed,which poses a great threat to the safe operation of trains.Investigations found that there is no dedicated equipment for icing detection of high-speed trains at home and abroad.All railway bureaus generally adopt the method of spraying anti-icing liquid to prevent icing,which can't perform well during the actual operation of trains.And the icing situation is more complicated after spraying with anti-icing fluid,which makes testing more difficult.This paper studies a kind of a kind of icing status sensor for high-speed EMU train(referred to as EISS),and realizes the icing detection under the EMU train bottom environment.This paper proposes a method for calculating resonant frequency through equivalent stiffness and equivalent mass and then a three-layer thin plate model is established.Based on the model,a sensor and a wireless ice detection system based on the sensor are designed.In this paper,the mechanics principle of the sensor model is described in detail.The equations for calculating the equivalent stiffness and the equivalent mass of the resonant system are deduced.The piezoelectric effect,the mechanism of the interference coupling,and the suppression method are studied and analyzed.The wireless detection system and the principles of each part are also described in detail,which includes the design of mechanical structure,hardware circuit and the software algorithm.During the development of the sensor and icing detection system,a large number of tests were conducted,including the principle verification test,temperature characteristic test,basic icing condition determination test,over-range measurement test and antifreeze icing test.Tests show that the actual measurement frequency of the sensor is in good agreement with the theoretical frequency of the model.At the same time,the stability and accuracy of the entire ice detection system meet the requirements of practical applications.The sensor can achieve the detection of multiple types ice accurately,and the measurement range of the liquid is 0~5mm,the measurement range of the ice is 0~3mm,and it also determined accurately the icing state under the complex condition after spraying the anti-icing fluid.