基于STM32的超声波风速低采样检测技术

Low Sampling Rate Detection Technology of Ultrasonic Wind Measurement Based on STM32

为实现风速传感器的高精度、低成本、低功耗等特性,基于超声时差原理提出一种低采样率的超声波双向风速检测方法。以STM32为核心,外围器件少,成本低,通过低速率采样方式实现了超声波信号波峰幅值及过零点时间采集,采用可变阈值算法完成超声波飞行时间的快速计算,基于电源管理及休眠技术实现整机低功耗。同时介绍了硬件电路设计,并通过高精度音速喷嘴装置检验了原型机性能,在23 m/s风速范围内,精度可达到0.15 m/s,相对不确定度约为0.3%。

In order to obtain high precision,cost effectivity,low power and other characteristics of wind sensor,a low sampling rate design of ultrasonic wind measurement was proposed based on time-difference method.The design employed STM32 microcontroller as the core.Its cost was low due to the fewer peripherals.The peak value and zero-crossing time of ultrasonic signal were obtained with low sampling rate.The transit time of ultrasonic was calculated rapidly with variable threshold method.And the low power of module was realized based on power management technology and sleep technology.In addition,the hardware electrical design was also introduced.The performance of prototype was verified by high precision gas flow equipment.The results show that the accuracy can reach 0.15 m/s and the relative uncertainty is about 0.3%in the wind speed range of 23 m/s.