【摘要】 有别于通常的通过测量发射和接收到超声波时间差测距原理,提出了一种根据相位差比较法超声波测距的原理。用低频正弦信号调制超声波,通过测量发射端与接收端的低频正弦信号相位差来实现测量目标与发射机之间的距离。通过改变正弦信号波的频率,可以改变相位差对距离的细分尺度,从而可提高测量精度,并且可达到切换测距量程的目的。实验表明,该测距方法具有抗干扰能力较强、实时测量的特点;分别针对7m和14m的测距量程,测量精度分别为0.5cm和1cm,盲区小于7cm。更多还原

【Abstract】 To increase the system’s antijamming ability and the measurement accuracy,an ultrasonic distance measurement based on the phase-difference between the sending and the receiving signal was presented.A low frequency sine signal was modulate to an ultrasonic wave,and then the ultrasonic wave was sent to the measured object,and reflected by the measured object.Through comparing the phase-difference between the sine signal demodulating from the ultrasonic wave and the sending signal,the distance between the measured object and the transmitter was obtained.In order to increase the precision,different frequency sine waves were selected to measure different measurement range.Experiments results showed that the system has the characteristics of the measurement blind area of 7 cm and the measurement accuracy of 0.5 cm and 1 cm under the measurement range of 7 m and 14 m respectively.更多还原