Design And Simulation Of Ultrasonic Measurement Model Based On Time Difference Method

With the rapid advancement of industrial modernization,increasing environmental problems and the depletion of fossil energy are both alerting humans to the need to find renewable energy sources to replace fossil energy in nature.Wind energy resources in renewable energy have the advantages of large reserves,low carbon dioxide emissions.They have become the fastest-growing one among many renewable energy sources.Wind energy resources in renewable energy have become the fastest growing of many renewable energy sources due to their large reserves and low carbon dioxide emissions.Not only can wind energy be used as a renewable energy source to benefit mankind,but effective observation of wind energy also plays an important role in environmental monitoring,and disaster prevention and mitigation.At the same time,wind speed and direction,as the main elements of meteorological monitoring,can be mastered in real time,not only to provide favorable data for meteorological monitoring,but also to timely and accurately grasp the changes in wind information,which is of great significance to meteorological monitoring and the prevention of accidents.Therefore,it is particularly important to prepare a wind measuring instrument with high measurement accuracy and stable performance.The ultrasonic wind speed and direction sensor has become a development direction of wind speed and direction measurement instrument research by virtue of its advantages of no mechanical wear and high measuring accuracy.In this paper,the advantages and disadvantages of several common measurement methods are summarized through the comparison of various wind measurement techniques.At the same time,according to the principle of time difference,the model of wind speed and direction measurement is designed,and then the formula of ultrasonic wind speed and direction measurement is derived.In the aspect of hardware circuit,this paper adopted the modular design,chose the STM32 of low power consumption as well as the processing chip to design the peripheral circuit,then selected the 200 KHz ultrasonic transducer,design the ultrasonic echo signal amplification circuit and relied on the launch of ultrasonic transducer drive circuit and the part of the circuit simulation to prove its feasibility.In order to ensure the accuracy of the system,the TDC-GP22 chip with 22 ps timing accuracy is selected as the time measuring chip in this paper.In this article,KEIL software is used to code and debug each part of the code.The software design part includes the following: introduction of development environment,initialization subroutine,communication subroutine,ultrasonic drive emission and receive subroutine analysis,and TDC-GP22 register configuration.The wind speed data obtained from the experiment is denoised by the wavelet threshold to make the wind speed signal more accurate.Meanwhile,the least square method is used to fit the wind tunnel experimental data to obtain the optimal wind signal value for reference.The experimental results show that: the measurement accuracy reaches the advanced level,accuracy of wind speed measurement can be achieved ?0.5 m/s(wind?10 m/s)or 5% of the reading(wind>10 m/s),the accuracy of wind direction measurement can be achieved ?2?.