| Summary: | 碩士 === 國立臺灣大學 === 工程科學及海洋工程學研究所 === 107 === Wind is not just a nature phenomenon in this high tech and rapid-changing generation. As a clean and renewable energy, wind energy draws more attention while the environmental issues are highly concerned. To take advantage of the wind energy, monitoring the local wind speed and direction is an important part of the beginning.
Ultrasonic anemometers possess some advantages of resisting extreme weather, shorter responding time, silence, and simple operation over traditional wind speed measuring instruments. Moreover, ultrasonic anemometers are not assembled by many parts, that can reduce the wear and tear of the instruments.
To provide an accurate measurement of wind speed, the ultrasonic anemometer is presented in this paper, which applies the property that the time of flight (ToF) of ultrasound between two transducers depends on the environmental air flow. The system takes ultrasonic transducer as the sensor, and the STM32 F303ZE microcontroller as the control core to command the system. The system can transmit and receive massive signal and captures the signal in the head wind and tail wind. After collecting the signals, the microcontroller will send the data to the computer and do the further algorithm. The algorithm is bases on the cross-correlation theorem, which is frequently used to verify the time delay of two signals. Finally, the wind speed and direction information are obtained by the vector calculation. The system is capable of switching the transducer between transmit mode and receive mode only by digital control, and be able to transmit and receive the signal independently.
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