The Design Of Ultrasonic Anemometer Based On Time Difference Method

The accurate measurement of wind speed and direction can be widely used in weather forecasting,navigation,environmental monitoring,agroforestry production,wind power generation,and scientific research.The traditional wind gauge is a contact measuring instrument with mechanical wear and large errors.Ultrasonic wind instruments have been developed to overcome some of the shortcomings of traditional wind instruments.However,studies have found that there are some problems with ultrasonic wind instruments in China.Since most of the ultrasonic anemometers are designed with four-way drive transmitter circuits,complex high-speed analog-to-digital conversions,and temperature measurement circuits that complicate circuit design,the time measurement accuracy of the system is low,resulting in low measurement accuracy of wind speed and direction,and no temperature measurement.Accuracy and the inability to timely and effectively heat up cause severe measurement errors such as frost and snow.In order to solve the above problems,this paper studied the new design of ultrasonic anemometer based on the time difference method,mainly including the launch drive circuit,TDC-GP22 measurement module,receive signal conditioning circuit,channel selection circuit,and heating circuit.The TDC-GP22 chip with a time measurement resolution of 22ps can be designed with a high-precision time measurement circuit to ensure the measurement accuracy of the aerofoil.One-way driver transmitter circuit was designed to drive four probes.At the same time,TDC-GP22 was used instead of the conventional temperature measurement circuit for high-precision temperature measurement,which not only simplifies the circuit design but also ensures the accuracy of temperature measurement.The default threshold algorithm of wavelet transform is used to perform noise reduction on the measured data,which effectively filters out noise interference and guarantees the accuracy and stability of the measurement.By studying the effect of the number of different transmitted pulses on the quality of the received signal,the number of optimal transmitted pulses is determined to improve the performance of the system.In this paper,the improvement measures in the above-mentioned aspects are taken as breakthrough points for innovation and an ultrasonic wind measuring instrument has been developed,and calibration testing and error analysis have been conducted.Through the test,it can be concluded that the ultrasonic wind instrument designed in this paper has reliable measurement accuracy and stability,meets the expected requirements,and has high practical value.