金屬內(nèi)傷探測器設計研究論文

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1、畢業(yè)設計(論文)金屬內(nèi)傷探測器設計研究摘要本文是基于單片機AT89S52，利用電感式接近開關(guān)傳感器LJ18A4-10-Z/BD設計一個簡易金屬探測器用于檢測金屬存在并進行金屬個數(shù)計數(shù)，包括硬件電路和軟件設計兩大部分。硬件電路由傳感器外圍電路和單片機外圍電路構(gòu)成。電感式接近開關(guān)傳感器是一個感應金屬物體的線性器件，型號為LJ18A4-10-Z/BD的接近開關(guān)在沒有檢測到金屬時會輸出一個電流值，但當檢測到金屬時，輸出電流值會發(fā)生變化。傳感器輸出為電流信號，不能直接進行A/D轉(zhuǎn)換，應通過電流電壓轉(zhuǎn)換電路，把傳感器輸出電流信號轉(zhuǎn)換為滿足A/D轉(zhuǎn)換器PCF8591輸入要求的電壓

2、信號。經(jīng)過A/D轉(zhuǎn)換后的數(shù)字信號，送入單片機處理。軟件設計主要包括A/D轉(zhuǎn)換、數(shù)據(jù)處理、LCD顯示和報警程序四大模塊。PCF8591采集系統(tǒng)開機電壓U0和進入金屬檢測狀態(tài)時的電壓U(x)。數(shù)據(jù)處理主要完成電壓值的精度轉(zhuǎn)換，要求精確到小數(shù)后第二位；計算U0和U(x)差值，并判斷電壓差值和傳感器預設靈敏度是否相等，從而判斷是否檢測到金屬。當傳感器檢測到金屬時，蜂鳴器報警，同時LCD顯示已檢測到的金屬個數(shù)。關(guān)鍵詞：金屬檢測；金屬計數(shù)；單片機AT89S52；A/D轉(zhuǎn)換器PCF8591；電感式接近開關(guān)LJ18A4-10-Z/BDAbstractInthispaper,itis

3、todesignasimplemetaldetectorthatcancounttheexistingmetalnumbersonthebasisofmicro-controllerAT89S52andinductiveproximityswitchsensorLJ18A4-10-Z/BD,includingthedesignofhardwarecircuitandsoftware.Thedesignofhardwarecircuitismadeupofthesensor’speripheralcircuitandthemicro-controller’sperip

4、heralcircuit.Inductiveproximityswitchislineardevicethatcaninducetheexistingofmetal.LJ18A4-10-Z/BDsensorwilloutputacurrentwithoutmeasuredobject.Untilitinducesmetal,theoutputcurrentwillbechanged.Becausetheoutputcurrentcannotbeconvertedtodigitalsignaldirectly,currenttovoltageconvertingcir

5、cuithastobeneeded,whichchangestheoutputcurrentsignalofsensorintovoltagesignalthatsatisfiestheinputrequirementsofPCF8591.Afteranalogtodigitalconverter(ADC),thedigitalsignalissenttomicro-controllerforprocessing.ThedesignofsoftwarecontainsfourpartswhichareADC,dateprocessing,liquidcrystald

6、isplay(LCD)andbeepalarming.PCF8591collectstheinitialvoltageUoandU(x).U(x)isthevoltagewhenthesensorisinconditionofdetectingmetal.Inthemoduleofdataprocessingitcompletestheprecisionchangingofcollectedvoltageandcorrectstheresultsto2decimalplaces,meanwhileitcalculatesthedifferencebetweenthe

7、valueofUoandU(x),thencomparethedifferencevaluewiththesensor’spre-establishedprecisionvaluetodecidewhetherthesensorhasinducedmetal.TheBeeperalarmsuntildetectingmetal,atthesametimetheLCDdisplaysthenumberofinducedmetals.Keywords:mentaldetection；metalnumbercounting；micro-controllerAT89S5