摘要
超声波飞行时间测量极易受到噪声的干扰而影响检测精度。针对这一难点,利用幅值、相位调节技术驱动超声波换能器产生自干涉发射波形,通过相位检测预判接收信号到达时间,结合双阈值拟合算法计算飞行时间。该系统以信号处理器DSP为核心,采用CPLD完成高精度数字相位检测。与传统的超声波飞行时间阈值检测方法相比,该系统具有测量精度高、抑制噪声干扰等优点。
Determination accuracy of ultrasonic time-of-flight can be easily affected by noises in practical measurements.Focusing on this problem,this paper combines with three advanced techniques to achieve the accurate time-of-flight measurement.Firstly,self-interference driving ultarsonic waves are stimulated from the piezoelectric transducer by amplitude and phase modulation techniques.Secondly,phase monitor is designed for roughly pre-detecting the received ultrasonic wave arrival time.Finally,double-threshold algorithm is employed for the final time-of-flight determination.The system is integrated in a single PCB board that is made up of digital signal processor,complex programmable logic device and some functional modules.Comparing with the traditional ultrasonic time-of-flight threshold crossing method,the systen has some advantages such as high resolution and high nosie suppression.
出处
《传感技术学报》
CAS
CSCD
北大核心
2010年第10期1439-1443,共5页
Chinese Journal of Sensors and Actuators
关键词
超声波
自干涉
数值拟合
飞行时间
ultrasonic wave
self-interference
numerical simulation
time-of-flight
