摘要
基于超声走时法的超声测距精度依赖于声速和超声到达时间测量,据此设计了大发射功率、高频率超声发射模块,以实现较大的超声测量距离同时具有较高的分辨率,设计了具有放大倍数可调的二级精密仪表放大电路和高品质因数的滤波电路的超声接收模块,以适应不同的测量范围,并抑制共模干扰信号和其他频率信号的干扰,采用小波软阈值降噪来判定超声首波到达时间,并采用标准距离测量来确定环境声速。实验结果表明,该系统在1m范围内精度高于1mm,5m范围内精度高于1.7mm,实现了较高的测量精度。
Distance measuring precision based on the method of ultrasonic travel time depends on the measuring of sound velocity and reaching time of ultrasonic.Accordingly,ultrasonic transmitter module with high power,high frequency ultrasonic is designed to achieve longer measuring distance and higher resolution simultaneously.And ultrasonic receiving module with two level instrument amplification circuit of adjustable magnification,filter circuit of high Q factor is designed to adapt various measuring range and restrain interfere of common mode signal and signals of other frequency.Wavelet threshold method is used to decide arriving time of first wave.The method of measuring standard distance is used to ascertain sound velocity under the condition.The experiment results show that the system precision is higher than 1 mm in the range of 1 m,and 1.7 mm in 5 m,so it achieves high measuring precision.
出处
《电子测量技术》
2013年第10期16-18,30,共4页
Electronic Measurement Technology
关键词
精度
超声走时
小波软阈值降噪
声速
precision
ultrasonic travel time
wavelet threshold
sound velocity
