The Research Of Monitoring System Of The Train Angle Cock Closed Based On Thermal Flow Transmitter

The safety of railway transportation is related to the life and property of the people of the whole country.A lot of research work has been carried out,and a variety of safety monitoring and testing devices have been developed successfully.In view of the train operation process of endangering the safety that important issues,key parts and components,integrated and built a fully functional,systematic,platform-based locomotive vehicle safety protection system,referred to as 6A system.The 6A system mainly realizes real-time monitoring of six common faults of air brake,power supply,insulation equipment,video,fire and travel faults.Train air brake system,basically rely on compressed air to brake,it is mainly dependent on the vehicle through the brake pipe to achieve the control of the train speed and parking.Angle cock closed will lead to the lack of air between the vehicles,so that the compressed air can not flow to the brake and the brake out of control,causing the train traffic accident.This paper studied the monitoring system for train angle cock closed based on thermal flow transmitter.Firstly,the working principle of the train air brake system is studied,and the mathematical model of the charging and discharging of the angle cock closed is established.By collecting the air flow and pressure signals,according to the mathematical model of the charge and exhaust,get the number of the breakthrough train tube cars per train and ensure the safety of the train operstion.Designed a thermal air flow transmitter based on constant temperature difference which integrated with measuring speed and temperature platinum resistance,measure the air flow of the charge and exhaust of the train.The using of constant temperature difference Wheatstone bridge circuit can effectively compensate for the impact of ambient temperature on air flow.The mathematical model of air flow and bridge circuit voltage signal is established by using polynomial least squares method.After data processing,output the standard 4?20mA current signal.It has the advantages of fast response,wide measurement range,high precision and good repeatability,and meets the requirements of the system.Designed the software and hardware of the angle cock closed monitoring module in the monitoring system of the angle cock closed,the hardware circuit design includes acquisition unit,storage unit,single-chip and some supporting peripheral circuits.The system automatically monitors the status of the entire train brake,such as flow,pressure,memory,the position of angle cock closed,failure and so on.Finally,sent these messages to the 6A system through serial communication and monitored the status of the train operation on real-time.