Development Of High Speed Infrared Temperature Measurement System For Track Plate In Alpine Region

The surface temperature of the ballastless track slab is an important factor for detecting the safety of the railway track.In the alpine region,the annual temperature is relatively large.And the temperature rise and fall may damage the stability of the track slab structure,resulting in warping or cracking.In order to accurately obtain the temperature information on the surface of ballastless track slab,a high-speed infrared temperature measurement system for track slab in alpine region is developed.The temperature of track slab can be measured by infrared radiation method,which can achieve the measurement accuracy of ±2℃ and measurement interval of less than 2ms.The mains job are as follows:(1)Determine the overall development plan of the system which includes the upper and lower computers.The PVMI-2TE photovoltaic infrared detector module is selected as the infrared detector of the system.It has good detection performance at wavelengths of 2μm~12μm,and has accurate signal output under the detection target of-40℃~+60℃.The weak signal amplification circuit design is completed to ensure the measurement resolution of the system.The high-speed data acquisition board is used to convert the amplified analog signal into a digital signal.The lower computer communicates with the upper computer through the network line.They cooperate to filter,process and calculate the signals.After processing,the signal is converted into a current signal by digital-to-analog conversion and V/I conversion for long-distance transmission to reduce the loss.The design of temperature control system ensures that the internal environment of the lower computer is about 20℃.The Emp-LX800 PC/104 CPU module is selected as the main controller to control the specific acquisition,conversion and processing operations.The development of system software such as real-time measurement part,calibration part and calibration part was completed.(2)The low-temperature blackbody radiation source was developed.This paper gives the solution of low temperature blackbody radiation source refrigeration,temperature control and low temperature frosting.It is used to calibrate and test the high speed infrared temperature measurement system of track slab in alpine regions.(3)We carried out high and low temperature experiments,calibration experiments and measurement accuracy experiments of the system,using least square method to calibrate the system,and analyzed the factors which affects the measurement accuracy of the system.The experimental results show that the high-speed infrared temperature measurement system of the track slab can operate in extreme weather for a long time,and the measurement accuracy meets ±2℃.