Ultrasonic distance measuring device

Abstract

The invention provides an ultrasonic distance measuring device. The ultrasonic distance measuring device comprises a control unit for outputting recurrent pulse strings, an ultrasonic wave transmitting and driving circuit for converting the recurrent pulse strings into recurrent sine wave signals, an intermediate frequency transformer for performing boosting processing on the recurrent sine wave signals, an ultrasonic transmitting-receiving integrated probe for transmitting ultrasonic signals to obstacles after being excited by the signals, receiving ultrasonic signals reflected by the obstacle and producing voltage signals corresponding to the reflected ultrasonic signals, a signal amplification circuit, a band-pass filtering circuit, a signal comparison circuit for converting filtered voltage signals into recurrent pulse signals, wherein the signal amplification circuit and the band-pass filtering circuit are respectively used for amplifying and filtering the voltage signal, and the control unit is further used for obtaining a measured distance according to output recurrent pulse strings and the recurrent pulse signals output by the signal comparison circuit. Compared with the prior art, the distance measured by the ultrasonic distance measuring device is large.

Description

technical field [0001] The invention relates to the technical field of ultrasonic ranging, in particular to an ultrasonic ranging device. Background technique [0002] Ultrasonic waves are often used for distance measurement due to their strong directivity, slow energy consumption, and long distances in the medium. The principle of ultrasonic ranging is: drive the ultrasonic transmitter to emit ultrasonic waves to obstacles, and start timing while emitting ultrasonic waves. When the ultrasonic waves encounter obstacles on the way to propagate, they will return immediately, and the returned ultrasonic waves (ie reflected waves) will be sent by the ultrasonic receiver. Receive, and stop timing when receiving the reflected wave, and calculate the distance between the transmitting point and the obstacle according to the propagation speed of the ultrasonic wave in the air and the recorded time difference. [0003] It is generally faster and more convenient to measure the distanc...

AI Technical Summary

Problems solved by technology

However, the existing ultrasonic distance measuring device can measure a short distance, generally only 2m to 3.5m. Although it can meet the needs of the existing vehicle reversing radar, it cannot meet the needs of other systems that require higher measurement distances.

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