Design and Experimental Study of High Precision Ultrasonic Ranging System

Abstract

With the increasing use of ultrasonic ranging syste ms, their requirements are also increasing, requiring more accur ate measuring equipment. A design scheme of ultrasonic ranging system based on STM32 single chip microcomputer is proposed. Compared with the traditional SCM(single chip microcomputer), the main frequency and timer frequency of STM32 are as high a s 72 MHz, which improves the resolution of time measurement. When the timer is started, the PWM channel is started to drive the ultrasonic transmitter and the capture channel is input to cap ture the echo signal, which improves the measurement accuracy. On the basis of fully analyzing the blind area and error of ultrasonic ranging, the double operation amplifying circuit and band pass filtering circuit are designed, and the peak time of echo signal is detected by software algorithm, which simplifies the circuit. Experimental results show that the measurement accuracy of the system is high and the blind area is as low as 25mm.