外文文獻(xiàn)翻譯---一種精確測(cè)量?jī)A斜角度的光學(xué)傳感器

1、<p><b>　　中文2477字</b></p><p><b>　　畢業(yè)設(shè)計(jì)說(shuō)明書(shū)</b></p><p><b>　　英文文獻(xiàn)及中文翻譯</b></p><p>　　學(xué)生姓名： 學(xué)號(hào)： </p><p>　　學(xué) 院：

2、 </p><p>　　專 業(yè)： </p><p>　　指導(dǎo)教師： </p><p>　　Novel Optical Sensor for Precise Tilt Angle Measurement</p><p>　　Fan

3、 Hua, Ivan Reading and Fang ZhongPing</p><p>　　Singapore Institute of Manufacturing Technology</p><p>　　Nanyang Avenue 71, Singapore 638075, Email: hfan@simtech.a-star.edu.sg</p><p>

4、;<b>　　ABSTRACT</b></p><p>　　A novel optical sensor, which can measure inclination angle or tilt angle of two axes simultaneously and precisely, is introduced. This sensor is based on the principl

5、e of laser interference so it has very high accuracy. A prototype sensor is designed, built and evaluated to demonstrate the novel concept. It is an optoelectronic sensor. There are no moving parts in the sensor. A fluid

6、 horizontal that is absolutely perpendicular to the true vertical provides the reference plane. The angle between</p><p>　　Key words: tilt angle sensor, inclinometers, laser interference</p><p>

7、　　I. INTRODUCTION</p><p>　　There are several kinds of commercial sensor for tilt angle measurement, which are available in the market. Some known as tilt angle sensor, some are known as inclinometers. They b

8、ase on different working principles. Electrolytic liquid [1], capacitance [2] and pendulum [3] are the three main working principles that most tilt angle sensor or inclinometer usually base on. Here we propose a novel op

9、tical method and build up an optoelectronic sensor with laser, optical components and image sensor. </p><p>　　A prototype of the method has been built up and evaluated. Experimental results show the tilt ang

10、le changes relative to sea level can be detected at the accuracy of +-1 arc second within the measurement range of 700 arc seconds.</p><p>　　II. PRINCIPLE</p><p>　　Figure 1 illustrates the schem

11、atic diagram of working principle. Point O is the focal point of beam expanding lens. Point O can be considered as a point light source. It emits spherical wave-front. Liquid oil surface will always maintain horizontally

12、 due to the gravity force of the earth. The oil surface is used as the reference plane. The container is made of glass. Its bottom surface will incline together with the target object when the sensor is placed on the tar

13、get. The light from oil surfac</p><p><b>　　（1）</b></p><p>　　where n is the refraction index of glass.</p><p>　　When the tilt angle is tiny, the above equation can be sim

14、plified as</p><p><b>　?。?）</b></p><p>　　We can obtain the following equation from and </p><p><b>　　（3）</b></p><p>　　where r is the center positi

15、on of circular fringes. D is the distance of the receiving screen to the glass surface of oil box. h is the thickness of glass and oil. n is the refraction index of glass and oil ( here we assume the glass and oil have s

16、ame index since they are very close).</p><p>　　Assume that so that h is negligible relative to D.</p><p><b>　　(4)</b></p><p>　　From equation (4) n, D and h are fixed onc

17、e the setup is assembled. Let , called system constant. This system parameter can be obtained through calibration process.</p><p>　　Hence equation (4) can be written as</p><p><b>　　（5）<

18、/b></p><p>　　where r can be calculated with image processing technique and hence do the tilt angle .</p><p>　　Fig. 1 Schematic diagram of measurement principle</p><p>　　III. DESC

19、RIPTION OF SENSOR</p><p>　　Figure 2 shows the detail layout of the optical head of the sensor. It includes laser 1, beam expander 2, beam splitter 3, mirror 4 and liquid oil box 5. A point light source emits

20、 spherical wave-front. This beam goes through the oil box. It is reflected by the glass surface and oil surface respectively. These two wave-fronts meet together again after they pass different optical paths. If the cohe

21、rent length of the point light source is longer than the optical path difference, these two beams wi</p><p>　　Fig. 2 Layout of optical sensor head</p><p>　　As illustrated in Figure 2, the laser

22、1 emits a laser beam. This laser beam is expanded by a beam expander 2 to form a spherical wave-front beam. Subsequently this beam goes through the liquid oil box 5 perpendicularly. The reflections occur in the surfaces

23、formed by medias layers with different refraction indexes. The reflection ratio is determined by the formula when incident direction is perpendicularly to the reflection plane。</p><p><b>　?。?）</b>

24、;</p><p>　　Where andrepresent the diffraction index of the two medias. The closer the two reflection indexes the less light reflected. When equals to there is no reflection occurring at this surface.<

25、/p><p>　　While building the sensor one of the most important requirements is to make sure that the centers of all optical components are positioned on the same line, e.g. the optical axis. Due to mechanical tol

26、erance and the precise requirements of the sensor head, a fine tune on the alignment of the optical head is necessary to make sure the sensor can work well. The method begins with aligning the laser to enable the laser b

27、eam parallel to the base plate that all the optical components will be mounted </p><p>　　Fig. 3 Schematic diagram of oil box</p><p>　　Figure 3 shows the details of liquid oil box. The first surf

28、ace is formed by air-glass, called air-glass surface; the reflection ratio is about 3% since the refraction index of air is 1 and the glass we used is around 1.4. The second surface is formed by glass-oil, called glass-o

29、il surface. There is almost no reflection in this surface since we choose proper oil with the close refraction index with the glass. The third surface is constructed by the oil and air. So the reflection ratio is about t

30、</p><p>　　Fig. 4A Interference fringe patterns (center position, non tilted)</p><p>　　Fig. 4B Interference fringe patterns (side position, tilted angle)</p><p>　　IV. CONLUSION</p

31、><p>　　A novel optical sensor was invented. A prototype has been built up and evaluated. Accuracy of +-1 arc second within the measurement range of 700 arc seconds has been achieved. It can measure inclination

32、angle or tilt angle of two axes simultaneously and precisely. This sensor is based on the principle of laser interference. It has the following main advantages compare with other inclinometers.</p><p>　　(1)

33、High accurate. It is optical interference principle based sensor. Any variation less than , e.g.0.3 micron in optical path will cause the movement of interference fringe pattern. This tiny change is detected and converte

34、d to tilt angle.</p><p>　　(2) Insensitive to magnetic environment.</p><p>　　(3) Optoelectronic sensor, no mechanical moving parts.</p><p>　　(4) Two axes angles measurement at the sa

35、me time.</p><p>　　REFERENCES</p><p>　　[1] Olson, Jack R., “Electrolytic tilt sensor and method for manufacturing</p><p>　　same”, US patent, US6802132B1, 2004</p><p>　　[

36、2] Urano, Mitsuhiro, “Capacitance type liquid sensor”, Patent EP1515117A1,</p><p><b>　　2005</b></p><p>　　[3] Zabler, Erich, “ Tilt sensor”, Patent EP0768513A2, 1997</p><p&

37、gt;　　一種精確測(cè)量?jī)A斜角度的光學(xué)傳感器</p><p><b>　　摘 要</b></p><p>　　本文主要介紹了一種新型光學(xué)傳感器，它可以同時(shí)準(zhǔn)確地測(cè)量?jī)A斜角或兩軸傾斜角度。這種傳感器是基于激光干涉原理，因此具有很高的精度。設(shè)計(jì)制作了一個(gè)傳感器的模型來(lái)論證這個(gè)新的方法，這是一個(gè)光電傳感器,傳感器中沒(méi)有移動(dòng)的部分。由正交于鉛垂面的流動(dòng)水平面提供參考面。傳感器和

38、絕對(duì)水平面之間的角度隨著被測(cè)量的物體傾斜而改變，這些變化反映在條紋圖案的中心位置的轉(zhuǎn)移方式。不同的干涉條紋的中心位置隨傾斜角的變化而改變。干涉條紋圖案進(jìn)行記錄和處理，轉(zhuǎn)化為兩軸、水平和垂直傾斜角度。當(dāng)使用1024*1024像素的傳感器時(shí)，測(cè)量范圍為700弧秒，其精度可高達(dá)+/ - 1弧秒。</p><p>　　關(guān)鍵詞：傾斜角度傳感器，傾斜儀，激光干涉</p><p><b>　　

39、I 介紹</b></p><p>　　市場(chǎng)上目前有幾種類型的商業(yè)傾斜角度測(cè)量傳感器。有些是角度傳感器，有些是傾斜儀，它們的工作原理不同。電解液體、電容和鐘擺是現(xiàn)在大多數(shù)傾斜角度傳感器和傾斜儀的三個(gè)主要工作原理。在這里，我們提出了一種新的光學(xué)方法，建立了一個(gè)用激光、光學(xué)元件和圖像傳感器的光電傳感器，它可以同時(shí)做精確的傾斜角度測(cè)量，不需要進(jìn)行機(jī)械的移動(dòng)，其工作原理是基于光學(xué)干涉，相干激光作為光源。光線通過(guò)

40、一個(gè)裝滿液態(tài)油的玻璃油盒。由正交于鉛垂面的流動(dòng)水平面提供參考面。當(dāng)激光束穿過(guò)油箱有兩束光線反射回來(lái)，一束是液體的表面產(chǎn)生的，另一束是容器玻璃產(chǎn)生的，干涉條紋就是由這兩條光線形成的，條紋圖案將隨著傾斜角度的變化產(chǎn)生相應(yīng)的變化，條紋圖案采集和處理后將反映傾斜角度信息，光學(xué)工作原理使它不受磁場(chǎng)的影響。該傳感器可以同時(shí)測(cè)量?jī)奢S傾角。流動(dòng)的水平面確保了參考面是一個(gè)絕對(duì)的水平面。高靈敏度光學(xué)干涉測(cè)量原理，保證了較高的精度。</p>&

41、lt;p><b>　　II 原理</b></p><p>　　圖1說(shuō)明了工作原理示意圖，O點(diǎn)是光線擴(kuò)大鏡頭的焦點(diǎn)，O點(diǎn)可以看作是點(diǎn)光源，它發(fā)出球面波。由于地球重力的影響，液體油面始終保持水平，因此用油面作為參考平面。該容器是玻璃材料的。當(dāng)傳感器被放在目標(biāo)表面時(shí)，其底部表面將連同目標(biāo)對(duì)象一起傾斜。</p><p>　　圖1 測(cè)量原理工作示意圖</p>

42、<p>　　從油面和玻璃表面射出的光將干涉形成圓形圖案（見(jiàn)圖4）。傾斜角度可以通過(guò)圓形圖案中心位置的改變測(cè)量得出。P是點(diǎn)O在玻璃和空間之間形成的鏡像，點(diǎn)Q則是點(diǎn)O在油和空氣之間形成的鏡像，油—空氣平面代表了水平面。當(dāng)使玻璃面平行油面，點(diǎn)P和點(diǎn)Q在垂直于油面的同一條線上，這條線也是光學(xué)系統(tǒng)的軸線。邊緣與共同中心圓形邊緣。當(dāng)油箱傾斜玻璃表面有一對(duì)以油面的傾斜角，這是同心圓圖案。當(dāng)油盒傾斜時(shí)，玻璃面相對(duì)于油面有個(gè)傾斜角。</

43、p><p><b>　?。?）</b></p><p>　　其中n是玻璃的折射率。當(dāng)傾斜角度很小，上面的方程可以簡(jiǎn)化為 （2）</p><p>　　我們可以從和得到以下方程：</p><p><b>　?。?）</b></p><p>　　其中是圓條紋中心的位置，

44、0;D是接收屏幕到油箱玻璃表面的距離，H是玻璃和油的厚度， n是玻璃和油折射率（因?yàn)椴ＡШ陀偷恼凵渎史浅＝咏?，這里假設(shè)它們相等）。假設(shè)折射率nD遠(yuǎn)遠(yuǎn)大于h，因此相對(duì)于來(lái)說(shuō)h可以忽略不計(jì)。</p><p><b>　　(4)</b></p><p>　　從方程（4）可知，一旦裝置安裝好后，n,d,h是固定的。令,為系統(tǒng)常量，系統(tǒng)參數(shù)可以通過(guò)校驗(yàn)過(guò)程獲得。&l

45、t;/p><p>　　因此方程(4)可以寫(xiě)成 </p><p><b>　?。?）</b></p><p>　　其中可以通過(guò)圖像處理技術(shù)計(jì)算出,由此可以得出值。</p><p>　　III. 傳感器的描述</p><p>　　圖2顯示了傳感器的光學(xué)頭部詳細(xì)布局。它包括激光1，擴(kuò)束2，光束分離器3，平面

46、鏡4和液體油盒5。一個(gè)點(diǎn)光源發(fā)出球面波，這束光線穿過(guò)油箱。這束光線分別被玻璃表面和油的表面反射，兩束不同路線的光將再次相遇再次相聚。如果點(diǎn)光源相干長(zhǎng)度大于長(zhǎng)的光程差，這兩束光線將產(chǎn)生干涉形成環(huán)形條紋。當(dāng)一個(gè)表面發(fā)生傾斜，圓形條紋中心將相應(yīng)地轉(zhuǎn)變。當(dāng)光學(xué)路徑變化，條紋將相應(yīng)的出現(xiàn)或者被吸收。條紋變化發(fā)生在一個(gè)相對(duì)應(yīng)的光程差，其中為光源的波長(zhǎng)。</p><p>　　圖2 光學(xué)傳感器布局</p><

47、p>　　如圖2所示，激光發(fā)射激光束1。激光束通過(guò)擴(kuò)束2被擴(kuò)大，形成一個(gè)球形波前束，隨后這束光線垂直穿過(guò)液態(tài)油盒5，在幾種不同折射率的媒介表面形成反射。當(dāng)入射方向垂直于反射面時(shí)，反射率是由下面公式?jīng)Q定的。</p><p><b>　?。?）</b></p><p>　　其中，和代表了兩個(gè)媒介的衍射指數(shù)。兩個(gè)反射率越近，將會(huì)有更少的光被反射。當(dāng)?shù)扔跁r(shí)，這個(gè)表面不存在

48、反射。</p><p>　　然而構(gòu)建這個(gè)傳感器的最終要的一個(gè)要求是所有光學(xué)器件的中心放在同一條線上，例如：光軸。由于機(jī)械公差和傳感器頭部的明確要求，對(duì)光學(xué)器件進(jìn)行校準(zhǔn)微調(diào)是必要的，以確保傳感器能夠正常工作。該方法首先對(duì)準(zhǔn)激光，使激光束平行于所有的光學(xué)組件安裝在基板，然后安裝光束分離器，激光束的方向隨一個(gè)直角和入射到油盒的光線改變。調(diào)整光束分離器直到入射光線垂直入射到液體油盒，對(duì)準(zhǔn)光軸與系統(tǒng)擴(kuò)束軸。從玻璃表面和油表

49、面的反射光波將被平面鏡以直角改變方向射入相機(jī)，使相機(jī)對(duì)準(zhǔn)確保激光束在成像平面的中心成像。也就是說(shuō)，成像軸垂直于成像平面。而且，該方法需要用三個(gè)10號(hào)螺絲進(jìn)一步配合三個(gè)油箱安裝，以確保傾斜角度在測(cè)量范圍內(nèi)，這樣一個(gè)圓形條紋圖案將出現(xiàn)。調(diào)整10號(hào)螺絲直到條紋圖案中心放在圖像傳感器中心，如圖4A所示</p><p><b>　　圖3 油盒原理圖</b></p><p>　　

50、圖3顯示了液態(tài)油盒的原理圖。第一個(gè)表面是由空氣和玻璃形成的，稱為空氣-玻璃表面，其反射率約為3％，因?yàn)榭諝獾恼凵渎适?，我們使用的玻璃折射率約為1.4。第二面是玻璃和油形成的，稱為玻璃-油面，這個(gè)表面幾乎沒(méi)有反射，因?yàn)槲覀冞x擇的油的折射率和玻璃的相近。第三個(gè)表面是油和空氣形成的，因此這個(gè)反射率大約等于第一個(gè)表面的。第一個(gè)玻璃-空氣表面和第三個(gè)油-空氣表面反射的波相遇后互相干涉，形成一個(gè)如圖4所示的圓形的干涉圖案。當(dāng)玻璃表面與油面平行，該

51、中心將被定位在（圖4A）光軸。當(dāng)傾斜角度變化時(shí)，圓形條紋中心的位置也將變化（圖4B）。</p><p>　　圖4A 干涉條紋圖案（中心，無(wú)傾斜角） 圖4B 干涉條紋圖案（邊緣，有傾斜角）</p><p><b>　　IV. 總結(jié)</b></p><p>　　本文主要發(fā)明了一種新型光學(xué)傳感器，建立了模型并進(jìn)行了評(píng)估，測(cè)量范圍為700弧秒，精度為+

52、 -1弧秒，它可以同時(shí)準(zhǔn)確地測(cè)量?jī)A斜角或兩軸傾斜角度。這種傳感器是基于激光干涉原理。與其他傾角儀比較它具有以下幾個(gè)主要優(yōu)點(diǎn)。</p><p>　　（1）精度高。它是基于傳感器的光學(xué)干涉原理。任何小于的變化，0.3微米的光路改變都會(huì)引起干涉條紋圖案的變化，檢測(cè)到微小的變化并轉(zhuǎn)換為傾斜角。</p><p>　?。?）對(duì)電磁環(huán)境不敏感。（3）光電傳感器，無(wú)機(jī)械運(yùn)動(dòng)部分。（4）同一時(shí)間進(jìn)行兩軸