Ultrasonic Anemometer Conditioning Circuit And Shadow Effect Research On Compensation Methods

When the cloud blocks the sun and heats the ground below,the temperature of the air in the shadow area decreases to form a high-pressure area.At the same time,the sun heats another area to form a low-pressure area.As an important clean energy,wind has been widely used in daily life.Accurate measurement of wind speed and direction is crucial in railway,aviation,navigation,military and meteorology.Due to the importance of wind speed and direction in these fields,a series of wind speed and direction detection systems came into being.Traditional wind measuring instruments include pitot tube,hotline,and mechanical types.Due to the narrow measurement range and mechanical presence of such instruments,Wear causes shortcomings such as short service life and low accuracy.It has gradually been replaced by an ultrasonic wind speed and direction indicator with a wide measurement range,short response time,high measurement accuracy,and strong anti-interference ability.The ultrasonic wind speed and direction indicator is a system that measures the wind speed and direction by using the characteristics of ultrasonic waves,and can well meet the application needs in related fields.After researching a variety of ultrasonic wind measurement technologies at home and abroad,this paper chooses the phase difference method as the main principle of ultrasonic wind measurement,and designs an ultrasonic wind speed measurement system based on STM32 microprocessor.The article will describe in detail the hardware,software,and simulation and compensation of shadow effects in the measurement system:The hardware part is designed based on the idea of modularity,with STM32 as the core of the system,and coordinated control of each peripheral circuit.The transducer sends out an ultrasonic signal through the drive circuit,and the receiving circuit completes the amplification and filtering of the pulse signal.The phase comparison module is used for pure output square wave proportional to the wind speed to measure the wind speed.The system can be accessed through the data storage unit Historical data,the communication between the outside world and the system is realized by the communication interface circuit.The software uses BP neural network to optimize the data received by the sensor,and design based on MATLAB to achieve compensation for shadow effects.This part receives the wind speed and direction data signals of the ultrasonic sensor and completes the functions of data storage and transmission.Finally,the assembled prototype was tested and measured in a wind tunnel inspection device,and the data was analyzed.The test results show that the accuracy of the wind speed can reach less than ± 5% of the measured value,and the accuracy of the wind direction can reach ± 3.50 °,which can meet the project The application requirements can realize all-weather measurement in most occasions,and have certain application prospects in the field of wind measurement.