Design Of Check Phase Type Ultrasonic Wind Speed Transmitter

At present, coal resources is still the main resource in our country and itsdamand continue to grow with the development of society, so the real-time andaccurate detection of coal mine underground environment parameters is veryimportant as the problem of coal mine safety production is more and moresignificant. In the process of coal mining, the dust, mash gas and carbonmonoxide etc. accumulate and the concentration of harmful substance will beincreasing, which causes potential safety hazard. In order to dilute the gasconcentration and discharge the dust outward timely in mine, it is necessary totransport fresh air into the mine through ventilation system constantly. So thewind speed monitoring in mine is one of the main contents in coal mine monitorsystem, which is the standard determines ventilation time and strength. Based onphase diversity, this paper puts forward to a design scheme of directional windspeed measurement system. With MSP430MCU as the core controller, thissystem analysizes and measures the time difference between upwind propagationand downwind propagation on two equal paths of ultrasonic phase difference, andsends effective electrical signals which are exchanged from time difference byanalog and digital circuit, then gets the wind information after processing insingle-chip microcomputer.This paper determines to use the ultrasonic phase difference principle todetect wind speed on the basis of summarizing and carding principle of severalkinds of test method of wind speed, compares and analyses ultrasonic probeallocation problem etc, on that base, establishes the mathematical model betweenthe wind speed and the phase difference signal, puts forward the temperaturecompensation measures, finishs the design of the check phase type ultrasonic wind speed transmitter. The system provides a modular processing of hardwareand devises the single chip microcomputer system circuit, power circuit,ultrasonic sensor drive circuit, signal processing circuit, frequency output circuitand connection fault alarming circuit, completes the PCB drawing, on that basis,and carries through circuit block and the overall debugging. The design ofsoftware side includes system initialization, infrared telecontrol calibration,temperature compensation, data processing of wind speed value, informationstorage, digital display function module design etc. On the basis of software andhardware design, this paper has tested the transmitter in the laboratory and thestandard wind tunnel, and analysed the testing results and error systemsystematized.The measured results show that the transducer is higher measuringprecision, wider measuring range, simple structure and small size, convenient forinstallation and debugging, and has broad application prospect.