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Research And Design Of Hardware Circuit Of Ultrasonic Ranging System

Posted on:2018-11-18Degree:MasterType:Thesis
Country:ChinaCandidate:Q WangFull Text:PDF
GTID:2322330512479949Subject:Electronic and communication engineering
Abstract/Summary:PDF Full Text Request
Ultrasonic ranging system is a non-contact detection mode. Compared with other optical detection or electromagnetism detection, ultrasonic ranging has no affected with light or color. Thus it do apply to some severe environment, such as dust, smoke,electromagnetism and poison. Based on the application of reversing radar, this thesis studied and designed the hardware system of ultrasonic ranging system in detail.This thesis firstly introduced the significance of reversing radar, current situation and development of ultrasonic ranging. It also introduced the basic characteristics of ultrasonic and the basic theory of ultrasonic ranging, analyzed the attenuation characteristic of ultrasonic transferred in the air. This thesis emphatically studied the classify and basic theory of auto gain control technology, designed the AGC circuit composed with variable gain amplifier and DAC. The AGC circuit could program-control the proper gain at the different distances, set a large gain at a long distance and set a small gain at a short distance. Then this thesis introduced the overall framework of the hardware system, designed the transmitter circuit and receiver circuit. The main function of transmitter circuit was to amplifier the signal waveform, so that it could drive the ultrasonic sensor to transfer the ultrasonic signal.The receiver circuit included amplifier circuit and filter circuit, such as the first low noise amplifier circuit, band-pass filter circuit, AGC circuit and ADC, every circuit schematic diagram was given in detail. Ultrasonic ranging system was greatly influenced by temperature, so this thesis designed the temperature compensation circuit to compensate the ultrasonic wave velocity, it could develop the precision of ranging. This thesis designed the PCB layout based on the layout principle.This thesis debugged and tested the hardware system, the experiment results showed that the ranging system could detect the distance from 20cm to 5m, the precision is 3mm. The AGC circuit developed the ranging precision, and could realize ranging with high precision.
Keywords/Search Tags:Ultrasonic ranging, Transmitter circuit, Receiver circuit, AGC circuit, Temperature compensation
PDF Full Text Request
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