電渦流傳感器位移特性實(shí)驗(yàn)報(bào)告

1、精選文檔電渦流傳感器位移特性試驗(yàn)試驗(yàn)報(bào)告 專業(yè)： 機(jī)械工程 班級(jí)： 機(jī)械7班 學(xué)號(hào)： 2201507003 姓名： 牛嘉彬 2015年11月20日一前言長(zhǎng)度是測(cè)量中最常見(jiàn)的物理量之一，我們經(jīng)常要通過(guò)推斷物體的位移量來(lái)推斷物體的狀態(tài)變化。除此之外，不少非位移變化量也是通過(guò)傳感器內(nèi)部器件相對(duì)位移來(lái)測(cè)量計(jì)算得出的。位移傳感器又稱為線性傳感器，是一種屬于金屬感應(yīng)的線性器件，傳感器的作用是把各種被測(cè)物理量轉(zhuǎn)換為電量。在生產(chǎn)過(guò)程中，位移的測(cè)量一般分為測(cè)量實(shí)物尺寸和機(jī)械位移兩種。按被測(cè)變量變換的形式不同，位移傳感器可分為模擬式和數(shù)字式兩種。模擬式又可分為物性型和結(jié)構(gòu)型兩種。常用位移傳感器以模擬式結(jié)構(gòu)型居多，

2、包括電位器式位移傳感器、電感式位移傳感器、自整角機(jī)、電容式位移傳感器、電渦流式位移傳感器、霍爾式位移傳感器等。數(shù)字式位移傳感器的一個(gè)重要優(yōu)點(diǎn)是便于將信號(hào)直接送入計(jì)算機(jī)系統(tǒng)。這種傳感器進(jìn)展快速，應(yīng)用日益廣泛。電渦流傳感器能靜態(tài)和動(dòng)態(tài)地非接觸、高線性度、高辨別力地測(cè)量被測(cè)金屬導(dǎo)體距探頭表面距離。作為一種非接觸的線性化計(jì)量工具，它能精確測(cè)量被測(cè)體（必需是金屬導(dǎo)體）與探頭端面之間靜態(tài)和動(dòng)態(tài)的相對(duì)位移變化。在高速旋轉(zhuǎn)機(jī)械和往復(fù)式運(yùn)動(dòng)機(jī)械狀態(tài)分析，振動(dòng)爭(zhēng)辯、分析測(cè)量中，對(duì)非接觸的高精度振動(dòng)、位移信號(hào)，能連續(xù)精確地采集到轉(zhuǎn)子振動(dòng)狀態(tài)的多種參數(shù)。如軸的徑向振動(dòng)、振幅以及軸向位置。電渦流傳感器以其長(zhǎng)期工作牢靠性

3、好、測(cè)量范圍寬、靈敏度高、辨別率高等優(yōu)點(diǎn)，在大型旋轉(zhuǎn)機(jī)械狀態(tài)的在線監(jiān)測(cè)與故障診斷中得到廣泛應(yīng)用。因此我們需要來(lái)了解電渦流傳感器的相關(guān)特性。二試驗(yàn)?zāi)康牧私怆姕u流傳感器測(cè)量位移的工作原理和特性。三電渦流傳感器的工作原理電渦流式傳感器是一種建立在渦流效應(yīng)原理上的傳感器。電渦流式傳感器由傳感器線圈和被測(cè)物體（導(dǎo)電體金屬渦流片）組成，如圖1所示。依據(jù)電磁感應(yīng)原理，當(dāng)傳感器線圈（一個(gè)扁平線圈）通以交變電流（頻率較高，一般為1MHz2MHz）I1時(shí)，線圈四周空間會(huì)產(chǎn)生交變磁場(chǎng)H1，當(dāng)線圈平面靠近某一導(dǎo)風(fēng)光時(shí)，由于線圈磁通鏈穿過(guò)導(dǎo)體，使導(dǎo)體的表面層感應(yīng)出呈旋渦狀自行閉合的電流I2，而I2所形成的磁通鏈又穿過(guò)傳

4、感器線圈，這樣線圈與渦流“線圈”形成了有肯定耦合的互感，最終原線圈反饋一等效電感，從而導(dǎo)致傳感器線圈的阻抗Z發(fā)生變化。我們可以把被測(cè)導(dǎo)體上形成的電渦等效成一個(gè)短路環(huán)，這樣就可得到如圖1的等效電路。圖中R1、L1為傳感器線        圖1電渦流傳感器原理圖           圖.2 電渦流傳感器等效電路圖圈的電阻和電感。短路環(huán)可以認(rèn)為是一匝短路線圈，其電阻為R2、電感為L(zhǎng)2。線圈與導(dǎo)體間存在一個(gè)互感M，它隨線圈與導(dǎo)體間距的減小而增大

5、。依據(jù)等效電路可列出電路方程組：    通過(guò)解方程組，可得I1、I2。因此傳感器線圈的復(fù)阻抗為： 線圈的等效電感為： 線圈的等效Q值為：QQ01-(222)/(122)1+(R222)/( R122) 式中：Q0 無(wú)渦流影響下線圈的值，Q01R1； 22 金屬導(dǎo)體中產(chǎn)生電渦流部分的阻抗，22R22+2L22。由式Z、L和式可以看出，線圈與金屬導(dǎo)體系統(tǒng)的阻抗Z、電感L和品質(zhì)因數(shù)值都是該系統(tǒng)互感系數(shù)平方的函數(shù)，而從麥克斯韋互感系數(shù)的基本公式動(dòng)身，可得互感系數(shù)是線圈與金屬導(dǎo)體間距離x(H)的非線性函數(shù)。因此Z、L、均是的非線性函數(shù)。雖然它整個(gè)函數(shù)是一非線性的，

6、其函數(shù)特征為"S"型曲線，但可以選取它近似為線性的一段。其實(shí)Z、L、的變化與導(dǎo)體的電導(dǎo)率、磁導(dǎo)率、幾何外形、線圈的幾何參數(shù)、激勵(lì)電流頻率以及線圈到被測(cè)導(dǎo)體間的距離有關(guān)。假如把握上述參數(shù)中的一個(gè)參數(shù)轉(zhuǎn)變，而其余參數(shù)不變，則阻抗就成為這個(gè)變化參數(shù)的單值函數(shù)。當(dāng)電渦流線圈、金屬渦流片以及激勵(lì)源確定后，并保持環(huán)境溫度不變，則只與距離x有關(guān)。于此，通過(guò)傳感器的調(diào)理電路（前置器）處理，將線圈阻抗Z、L、的變化轉(zhuǎn)化成電壓或電流的變化輸出。輸出信號(hào)的大小隨探頭到被測(cè)體表面之間的間距而變化，電渦流傳感器就是依據(jù)這一原理實(shí)現(xiàn)對(duì)金屬物體的位移、振動(dòng)等參數(shù)的測(cè)量。 為實(shí)現(xiàn)電渦流位移測(cè)量，必需有一個(gè)

7、專用的測(cè)量電路。這一測(cè)量電路（稱之為前置器，也稱電渦流變換器）應(yīng)包括具有肯定頻率的穩(wěn)定的震蕩器和一個(gè)檢波電路等。電渦流傳感器位移測(cè)量試驗(yàn)框圖如圖3所示：圖3 電渦流位移特性試驗(yàn)框圖依據(jù)電渦流傳感器的基本原理，將傳感器與被測(cè)體間的距離變換為傳感器的Q值、等效阻抗Z和等效電感L三個(gè)參數(shù)，用相應(yīng)的測(cè)量電路（前置器）來(lái)測(cè)量。本試驗(yàn)的渦流變換器為變頻調(diào)幅式測(cè)量電路，電路原理與面板如圖4所示。圖4電渦流變換器原理圖與面板圖 電路組成：Q1、C1、C2、C3組成電容三點(diǎn)式振蕩器，產(chǎn)生頻率為1MHz左右的正弦載波信號(hào)。電渦流傳感器接在振蕩回路中，傳感器線圈是振蕩回路的一個(gè)電感元件。振蕩器作用是將位移變化引起的

8、振蕩回路的Q值變化轉(zhuǎn)換成高頻載波信號(hào)的幅值變化。D1、C5、L2、C6組成了由二極管和LC形成的形濾波的檢波器。檢波器的作用是將高頻調(diào)幅信號(hào)中傳感器檢測(cè)到的低頻信號(hào)取出來(lái)。Q2組成射極跟隨器。射極跟隨器的作用是輸入、輸出匹配以獲得盡可能大的不失真輸出的幅度值。電渦流傳感器是通過(guò)傳感器端部線圈與被測(cè)物體（導(dǎo)電體）間的間隙變化來(lái)測(cè)物體的振動(dòng)相對(duì)位移量和靜位移的，它與被測(cè)物之間沒(méi)有直接的機(jī)械接觸，具有很寬的使用頻率范圍（從010Hz）。當(dāng)無(wú)被測(cè)導(dǎo)體時(shí)，振蕩器回路諧振于f0，傳感器端部線圈Q0為定值且最高，對(duì)應(yīng)的檢波輸出電壓Vo 最大。當(dāng)被測(cè)導(dǎo)體接近傳感器線圈時(shí)，線圈Q值發(fā)生變，振蕩器的諧振頻率發(fā)生變

9、化，諧振曲線變得平坦，檢波出的幅值Vo變小。Vo變化反映了位移的變化。電渦流傳感器在位移、振動(dòng)、轉(zhuǎn)速、探傷、厚度測(cè)量上得到應(yīng)用。四試驗(yàn)預(yù)備器材機(jī)頭中的振動(dòng)臺(tái)、測(cè)微頭、電渦流傳感器、被測(cè)體(鐵圓片)；顯示面板中的FV表（或電壓表）；調(diào)理電路面板傳感器輸出單元中的電渦流、調(diào)理電路面板中的渦流變換器五試驗(yàn)步驟1、調(diào)整測(cè)微頭初始位置的刻度值為5mm處，松開(kāi)電渦流傳感器的安裝軸套緊固螺釘，調(diào)整電渦流傳感器高度與電渦流檢測(cè)片相帖時(shí)擰緊軸套緊固螺釘并按圖5示意接線。圖5 電渦流傳感器位移特性試驗(yàn)接線示意圖2、將電壓表（FV表）量程切換開(kāi)關(guān)切換到20V檔，檢查接線無(wú)誤后合上主、副電源開(kāi)關(guān)（在渦流變換器輸入端可

10、接示波器觀測(cè)振蕩波形），登記電壓表讀數(shù)，然后逆時(shí)針調(diào)整測(cè)微頭微分筒每隔0.1mm讀一個(gè)數(shù)，直到輸出Vo變化很小為止并將數(shù)據(jù)列入表1表1 電渦流傳感器位移X與輸出電壓數(shù)據(jù)X（mm）7.27.17.06.96.86.76.66.56.46.3Vo(V)0-0.24-0.37-0.52-0.69-0.79-0.95-1.05-1.18-1.33Vo(V)0-0.24-0.37-0.53-0.68-0.79-0.97-1.06-1.20-1.33依據(jù)表1數(shù)據(jù)作出VX試驗(yàn)曲線。在試驗(yàn)曲線上截取線性較好的區(qū)域作為傳感器的位移量程計(jì)算靈敏度和線性度（可用最小二乘法或其它擬合直線）。試驗(yàn)完畢，關(guān)閉全部電源。六

11、數(shù)據(jù)分析Matlab使用GUI編輯m文件如下：function varargout = nihe_gui(varargin)%NIHE_GUI M-file for nihe_gui.fig% NIHE_GUI, by itself, creates a new NIHE_GUI or raises the existing% singleton*.% H = NIHE_GUI returns the handle to a new NIHE_GUI or the handle to% the existing singleton*.% NIHE_GUI('Property',

12、'Value',.) creates a new NIHE_GUI using the% given property value pairs. Unrecognized properties are passed via% varargin to nihe_gui_OpeningFcn. This calling syntax produces a% warning when there is an existing singleton*.% NIHE_GUI('CALLBACK') and NIHE_GUI('CALLBACK',hObjec

13、t,.) call the% local function named CALLBACK in NIHE_GUI.M with the given input% arguments.% *See GUI Options on GUIDE's Tools menu. Choose "GUI allows only one% instance to run (singleton)".% See also: GUIDE, GUIDATA, GUIHANDLES % Edit the above text to modify the response to help nih

14、e_gui % Last Modified by GUIDE v2.5 14-Dec-2015 19:05:47 % Begin initialization code - DO NOT EDITgui_Singleton = 1;gui_State = struct('gui_Name', mfilename, . 'gui_Singleton', gui_Singleton, . 'gui_OpeningFcn', nihe_gui_OpeningFcn, . 'gui_OutputFcn', nihe_gui_OutputF

15、cn, . 'gui_LayoutFcn', , . 'gui_Callback', );if nargin && ischar(varargin1) gui_State.gui_Callback = str2func(varargin1);end if nargout varargout1:nargout = gui_mainfcn(gui_State, varargin:);else gui_mainfcn(gui_State, varargin:);end% End initialization code - DO NOT EDIT % -

16、 Executes just before nihe_gui is made visible.function nihe_gui_OpeningFcn(hObject, eventdata, handles, varargin)% This function has no output args, see OutputFcn.% hObject handle to figure% eventdata reserved - to be defined in a future version of MATLAB% handles structure with handles and user da

17、ta (see GUIDATA)% varargin unrecognized PropertyName/PropertyValue pairs from the% command line (see VARARGIN) % Choose default command line output for nihe_guihandles.output = hObject; % Update handles structureguidata(hObject, handles); % UIWAIT makes nihe_gui wait for user response (see UIRESUME)

18、% uiwait(handles.figure1); % - Outputs from this function are returned to the command line.function varargout = nihe_gui_OutputFcn(hObject, eventdata, handles)% varargout cell array for returning output args (see VARARGOUT);% hObject handle to figure% eventdata reserved - to be defined in a future v

19、ersion of MATLAB% handles structure with handles and user data (see GUIDATA) % Get default command line output from handles structurevarargout1 = handles.output; function edit1_Callback(hObject, eventdata, handles)% hObject handle to edit1 (see GCBO)% eventdata reserved - to be defined in a future v

20、ersion of MATLAB% handles structure with handles and user data (see GUIDATA) % Hints: get(hObject,'String') returns contents of edit1 as text% str2double(get(hObject,'String') returns contents of edit1 as a double % - Executes during object creation, after setting all properties.func

21、tion edit1_CreateFcn(hObject, eventdata, handles)% hObject handle to edit1 (see GCBO)% eventdata reserved - to be defined in a future version of MATLAB% handles empty - handles not created until after all CreateFcns called % Hint: edit controls usually have a white background on Windows.% See ISPC a

22、nd COMPUTER.if ispc && isequal(get(hObject,'BackgroundColor'), get(0,'defaultUicontrolBackgroundColor') set(hObject,'BackgroundColor','white');end function edit2_Callback(hObject, eventdata, handles)% hObject handle to edit2 (see GCBO)% eventdata reserved - to

23、 be defined in a future version of MATLAB% handles structure with handles and user data (see GUIDATA) % Hints: get(hObject,'String') returns contents of edit2 as text% str2double(get(hObject,'String') returns contents of edit2 as a double % - Executes during object creation, after se

24、tting all properties.function edit2_CreateFcn(hObject, eventdata, handles)% hObject handle to edit2 (see GCBO)% eventdata reserved - to be defined in a future version of MATLAB% handles empty - handles not created until after all CreateFcns called % Hint: edit controls usually have a white backgroun

25、d on Windows.% See ISPC and COMPUTER.if ispc && isequal(get(hObject,'BackgroundColor'), get(0,'defaultUicontrolBackgroundColor') set(hObject,'BackgroundColor','white');end % - Executes on button press in pushbutton1.function pushbutton1_Callback(hObject, event

26、data, handles)% hObject handle to pushbutton1 (see GCBO)% eventdata reserved - to be defined in a future version of MATLAB% handles structure with handles and user data (see GUIDATA)x=str2num(get(handles.edit1,'string');y=str2num(get(handles.edit2,'string');p=polyfit(x,y,1);x1=max(x)

27、:-0.1:min(x);y2=polyval(p,x1);axes(handles.axes1)plot(x,y,'*r',x1,y2);% - Executes on button press in pushbutton2.function pushbutton2_Callback(hObject, eventdata, handles)% hObject handle to pushbutton2 (see GCBO)% eventdata reserved - to be defined in a future version of MATLAB% handles st

28、ructure with handles and user data (see GUIDATA)x=str2num(get(handles.edit1,'string');y=str2num(get(handles.edit2,'string');p=polyfit(x,y,1);x1=max(x):-0.1:min(x);y2=polyval(p,x1);e=abs(y-y2);axes(handles.axes1)plot(x,e); % - Executes on button press in pushbutton3.function pushbutto

29、n3_Callback(hObject, eventdata, handles)% hObject handle to pushbutton3 (see GCBO)% eventdata reserved - to be defined in a future version of MATLAB% handles structure with handles and user data (see GUIDATA)x=str2num(get(handles.edit1,'string');y=str2num(get(handles.edit2,'string');

30、y1=str2num(get(handles.edit3,'string');e2=abs(y-y1);x1=max(x):-0.1:min(x);axes(handles.axes1)plot(x,e2); % - Executes on button press in pushbutton4.function pushbutton4_Callback(hObject, eventdata, handles)% hObject handle to pushbutton4 (see GCBO)% eventdata reserved - to be defined in a f

31、uture version of MATLAB% handles structure with handles and user data (see GUIDATA)close; function edit3_Callback(hObject, eventdata, handles)% hObject handle to edit3 (see GCBO)% eventdata reserved - to be defined in a future version of MATLAB% handles structure with handles and user data (see GUID

32、ATA) % Hints: get(hObject,'String') returns contents of edit3 as text% str2double(get(hObject,'String') returns contents of edit3 as a double % - Executes during object creation, after setting all properties.function edit3_CreateFcn(hObject, eventdata, handles)% hObject handle to edi

33、t3 (see GCBO)% eventdata reserved - to be defined in a future version of MATLAB% handles empty - handles not created until after all CreateFcns called % Hint: edit controls usually have a white background on Windows.% See ISPC and COMPUTER.if ispc && isequal(get(hObject,'BackgroundColor&

34、#39;), get(0,'defaultUicontrolBackgroundColor') set(hObject,'BackgroundColor','white');end function edit4_Callback(hObject, eventdata, handles)% hObject handle to edit3 (see GCBO)% eventdata reserved - to be defined in a future version of MATLAB% handles structure with handles and user data (see GUIDATA) % Hints: get(hObject,'String&#