超声波传感器接收信号强度非对称性分析及对策

Analysis and Countermeasures to the Problem of Ultrasonic Sensor Receives the Ultrasonic Signal Asymmetric

针对采用时差法测量流速时,超声波传感器顺、逆两向接收信号强度存在的非对称性、非均匀性问题,提出了一种改善超声波传感器性能的方法。根据超声波传感器的波束角、发声传感器与受声传感器的间距,分别计算出超声波沿着波束角中心线和外线到达受声传感器表面的时间,进而通过改进压电元件模块提出一种缩短信号分别沿着中心线和外线到达受声传感器表面时间差的超声波传感器设计方法。理论分析可知,该方法可以有效地改善接收信号强度非均匀、非对称性问题,提高了流量测量精度。

Ultrasonic sensor receives the ultrasonic signal downstream and upstream when measuring the flow rate with the time difference method. However the received signal strength is irregular and asymmetrical. For the problem,a modified method to improve the performance of ultrasonic sensor is presented. According to the beam angle and the spacing of sending-side and receiving-side,the time arriving at the surface of ultrasonic sensor along the center and perimeter is calculated,respectively. Then,there is time difference existing when ultrasonic reaches the surface of the receiving-side sensor along the center and perimeter. To shorten it,this paper proposes a design method of ultrasonic sensor by improving the piezoelectric element structure of ultrasonic sensor. Theoretical analysis shows that the modified method can not only effectively improve the problem of irregularly and asymmetrically received signal strength,but also increase the accuracy of flow measurement.