Research And Design Of Three-dimensional Ultrasonic Wind Measurement System Along The Railway Line

The railway is the artery of transportation,and the monitoring of meteorological data along the railway is one of the important guarantees for the safe operation of trains.Wind is an important meteorological element.In order to obtain comprehensive and more detailed railway wind vector information,this paper designs a three-dimensional ultrasonic transducer array to measure wind speed and direction along the railway.It solves the problems of easy wear,low accuracy,and poor stability of traditional mechanical,electromagnetic and other anemometers.The formation of wind is random.Sound propagates under windy conditions,and the wind speed is vector superimposed on the speed of sound.According to the different propagation time of ultrasonic signal in the case of along and against wind,this paper uses the principle of time difference method to establish a three-dimensional wind measurement model.Six ultrasonic signals are time-sharing multiplexed,and a three-dimensional ultrasonic wind measurement system based on Cortex-M3 core and stm32f103rct6 as the main controller is designed.The hardware circuit adopts a modular design idea,and the system power circuit,ultrasonic transducer transmission and driving circuit,receiving gating circuit,amplifying and filtering signal processing circuits,as well as communication and heating circuits are respectively designed.The software is designed with MDK5 as the integrated development environment.The main controller emits 12 200 k Hz PWM wave pulses.After boosting,it drives the ultrasonic transducer to emit ultrasonic signals,and records the ultrasonic waves by controlling the corresponding external interrupts and system internal timer interrupts.The propagation time of the signal is measured in six loops.The median average filtering method is used to reduce the noise and control the data quality of the collected time data to ensure the accuracy and stability of the wind speed and direction data.At the same time,the system assisted in the design of the heating circuit to ensure that the instrument can work normally in harsh environments such as freezing,rain and snow,and finally completed the development of the three-dimensional ultrasonic wind measurement system.PCB test and signal test,meteorological observation base data comparison experiment were carried out on the ultrasonic anemometer,and EMC performance test and environmental test of the whole machine were carried out to verify the performance of the instrument.Among them,the wind speed and direction comparison experiment results show that the error range of wind speed and wind direction is within ±0.5m/s and ±2°,which can meet the measurement requirements of wind vector along the railway,and has high application value in the field of meteorological monitoring.