1272388 ，九、發明說明： •【發明所屬之技術領域】 。、本發明係關於一種雙軸向光學式加速度計，尤指一種 可運用於精後、之工業發展，以有效地量測機械振動，與解 /夫振動所造成的困擾，藉以達到精確量測振動量之目的 者。 【先前技術】 ’近年來由於機械之動力與速度機能的提高，為有 j降=機械振動所造成之影響，振動量的精確量測於精密 工業發展中更行重要，於精密機械設備隔震技術方面，主 要技術困難點在於感測技術與控制機制之設計，而整個主 =隔振系統之特性又與感測技術及控制機制 之設計有著 A不可77的關係’由於—般實驗室玉作人員在地板上行走 2產生的振動頻率在1〜他範圍，大地的脈動-般在0.1 • 1GHZ因此近年來針對精密機械設備的減振系統設計需 二備達1Hz以下之隔振頻率能力，亦即所使用的加速度計 里測功月匕必須成適合低頻量測，甚至可量測到接近沉頻 率的振動。 …加速度計為-種量測加速度的振動量測儀器，一般最 簡單的設計’乃藉由感測器予以記錄出加速度計内部感震 質量與其基座間的相對運動，進而得到基座的加速度，此 感測為’於現階段皆採用電容感測器、·T、壓電⑽T) 感測器與應變規來加以設計’而近年來隨著光纖通訊技術的成 /2388 度計^制=此有彻光纖作為此感測11峨計，触完成光學式加速 〜先美國專利編號u.s.Pat.NG.5,837,998揭露將 光纖因外A ’心孑樑方式固定住，當加速度作用於感测器結構上，使 量你班夕部振動產生彎曲時，利用一光感測器偵測光束能 纖作L來計算出作用於感測器結構上的加速度值。由於採用光 2感謂器所完成的加速度計，所需成本昂貴，因此顯少被實 ’丁、题、用於工業界上。 、 【發明内容】 雜=此本發明有鑑於習知之力口速度測量儀器之構造複 …製造成本高，而且精密度不足，在使用上具有諸多缺 點’因此本發明提供一種雙軸肖光學式加速度言十，其係在 於基座上分別固定有光學式二維角度量測裝置及感震裝 置，該光學式二維角度量測裝置係設有量測探頭，而該感 震衷置則設有雙軸向撓性鉸鍊，雙轴向撓性鉸鍊—端設有 感震質量’感震質量上係設有反射鏡；當基座受到振動 時’則感震質^:會產生角度擺動’與基座之間產生相對運 動’利用量測探頭之光源可以投射至感震質量之反射鏡 上，並賴反射鏡上之反射光做光束聚焦能量位置訊號處 理，藉以判斷感震質量與量測探頭間之相對運動，進而得 到基座的加速度。 本發明實施例確實具有下列之優點： 1.本發明係利用光學式二維角度量測裝置，其光學量測方 式具有極高角度量測解析度，且不易受到環境因素影響 1272388 〔例如：容電雜訊(triboelectric noise)、電磁干擾、濕 度、溫度變化…等〕之光學量測特性，藉以記錄出加速 度計内部感震質量與基座間的相對運動，進而得到基座 的加速度，其整體設計較目前的加速度計更為簡單，並 且在製作上更為容易。 2.本發明之感震裝置構造採用雙軸向撓性鉸鍊設計方式， 以撓性鉸鍊代替球窩接點所發展出的形變式感震結 • 構，利用結構間無摩擦生熱與可一體加工成型等優點， 使感震的精度有著明顯的改善。此雙軸向撓性鉸鍊感震 結構的設計方式，可針對選擇一特定量測頻寬來設計雙 轴向撓性鉸鍊的幾何形狀，並換算出彈性支承k值與搭 配感震質量m值，再以量測探頭記錄出感震質量與其基 座間的相對運動，進而間接求出基座加速度，因此針對 特定量測頻寬可設計完成一低成本、高靈敏度的光學式 加速度計。 ® 綜合以上所述優點，本創作之雙軸向光學式加速度 計，對精度日益要求的今日，實為一具實用性之創作。 為使貴審查委員對本創作裝置之内容及功用做更深 一層的暸解，茲針對本創作中之圖示及符號對照列示如 後，並於實施例之詳述中配合圖示說明。 【實施方式】 首先，請參閱第一、二、三圖，本發明之雙軸向光學 7 1272388 ， 式速度計，包括有： _ 基座（1)，其係設有第一固定面（11)，而相距於第一固 定面適當之距離處，則設有第二固定面（12)，該第二固定 面（12)上則設有透孔（13)。 光學式二維角度量測裝置(2)，如第四圖所示，其係固 定於基座（1)之第一固定面（11)上，該光學式二維角度量測 裝置（2)係設有一量測探頭（21)，該量測探頭（21)之内部係 • 分別設有二極體雷射(22)、分光鏡(23)、準直鏡(24)、及四 象限光感測器（25)〔 f〇ur_quadrant photo detector〕。 感震裝置（3)，其係固定於基座（1)之第二固定面（12) 上，該感震裝置(3)係設有一雙軸向撓性鉸鍊(32)，該雙轴 向撓性鉸鍊(32) —端則設有螺孔(34)，以供螺絲（35)穿過基 座（1)第二固定面（12)之透孔（13)而螺固，又於雙軸向撓性 鉸鍊(32)之另一端設有一感震質量(31)，於感震質量(31)底 修 部固定有一反射鏡(33)，藉以光學式二維角度量測裝置(2) 之光源可以投射至感震質量（31)底部之反射鏡(33)上，當基 座（1)受到橫向振動的影響時，該感震質量(31)將會角度擺 動，與基座（1)之間產生相對運動，並以光學式二維角度量 測裝置(2)偵測反射鏡(33)上之反射光做光束聚焦能量位置 訊號處理。 本發明之實施使用時，如第三圖所示，該感震裝置(3) 係固疋於基座（1)之上方處，而光學式二維角度量測裝置(2) 固疋在感震質量（31)下方的基座（1)上，光學式二維角度量 8 1272388 、 測裝置(2)之量测探頭(21)可投射雷射光束至固定於感震質 • 量（31)下方的反射鏡(33)表面上，反射鏡(33)之反射光投射 於光學式二維角度量測裝置(2)之四象限光感測器（25)，當 基座（1)置放於任何之待測物上時，受到待測物側向振動的 影響’其感震質量（31)將會產生角度擺動，經由四象限光 感測器（25)量測到一個光束聚焦能量位置訊號〔即四象限 之（π+πι)·(ι +r\〇= 0 γ和+ Πμ m+IV)= 0χ〕，經處 • 理電路後’將訊號藉由頻譜分析儀進行振動訊號分析。 其中量測探頭(21)之投射光束係由二極體雷射(22)射 向分光鏡(23)〔如第四圖所示〕，雷射光束在通過分光鏡(23) 後’經過一準直鏡(24)成平行光束投射至反射鏡上(33)，而 反射光束則循原路徑經準直鏡(24)與分光鏡(23)後而投射 至四象限光感測器（25)上。 本發明於光學量測原理上，係利用雷射準直量測法， 所謂雷射準直量測法是指當雷射光束之光轴對準四象限 • 光感測器（25)時，則四個光感測器所產生的輸出電壓皆相 同，當光束偏位則四個感測器將呈現不同的輸出電壓值， 這種不相同的輸出電壓值就可用來量測感震質量（31)的角 度偏擺情形，所以當感震質量（31)無角度偏擺時，經由準 直鏡(24)與分光鏡(23)的反射光會在四象限光感測器（25) 中心位置形成一個圓形區域，當感震質量(31)有角度偏擺 時，則經由準直鏡(24)與分光鏡(23)的反射光會在四象限光 感測器（25)非中心位置形成一個圓形區域。 9 Ϊ272388 以6» X軸向角度變化為例，當反射鏡(33)於如第四圖+ Θ X角度偏擺時’經準直鏡(24)與分光鏡(23)的反射光會聚 焦在四象限光感測器（25)形成如第五圖_A的光點位置，四 象限光感測器（25)訊號經由自製的光束聚焦能量處理電路 處理後為正電壓輸出，當反射鏡(33)位於第四圖無6>χ角 度偏擺時’反射光在四象限光感測器（25)會形成如第五圖 的光點位置，四象限光感測器（25)訊號經光束聚焦能量 _ 處理電路後為零電壓輸出，當反射鏡(33)於如第四圖 角度偏擺時，反射光在四象限光感測器（25)會形成如第五 圖-C的光點位置，四象限光感測器（25)訊號經光束聚焦能 量訊號處理電路的處理後為負電壓輸出，因此第六圖所示 曲線為角度偏擺與四象限光感測器（25)訊號輪出關係〔圖 形X軸為量測表面偏轉角度變化，而Υ軸為光束聚焦能量 戒號輸出〕’其中苐六圖Α、Β與C分別對應第五圖中a、 _ B與C三個訊號處理圖形，而第六圖曲線中的線性區域可 作為角度量測之用，為一動、靜態特性均優良之量測工具。 由於一般實驗室工作人員在地板上行走所產生的振 動頻率在1〜3Hz範圍，大地的脈動一般在〇1〜ι〇Ηζ。 因此近年來針對奈米量測儀器工作台的減振系統設計需 具備達1Hz以下之隔振頻率能力，亦即所使用的加速度計 里’則功月b必須犯適合低頻量測，所以本發明實施例的方式 針對低頻加速度計進行實施說明。 欲進一步完成雙軸向光學式加速度計，則所設計的感 .1272388 展焉量必須具有雙軸方向的運動功能，為達此功能，故採 • 用也變式感震結構設計方法，以雙軸向撓性鉸鍊來微型化 此結構接點(joint)，利用材料剛性的差異來模擬所要接點 的特性’而材料剛性的差異則由材料的幾何形狀來決定。 於感震結構設计上’若設計不同的加速度計共振頻 率’其頻率響應也就不同，而加速度計的實際應用上，一 般需針對所應用的領域來加以設計所需的頻率響應，今本 • 發明的雙軸向光學式加速度計實施例乃針對量測大地的 脈動（0.1〜10 Hz)為設計基礎，因此於低阻尼比的設計情形 下’頻率響應採以系統共振頻率的10%為設計基礎。因此 期望的加速度計共振頻率應約在100Hz左右。 首先將二維感震結構形狀幾何參數以ANSYS 8.0建 立3D幾何模型分析，元素種類採8節點Solid 45六面體 元素做為元素種類來進行分析。在理論分析中，感震結構 材料採用S304不鏽鋼，此材料的揚氏係數（Y〇ung，s 鲁 modulus)為 193 Gpa、質量密度（mass density)為 7860 kg/m3。感震結構之長、寬及高分別為15mm、l5mm、 34mm ’雙轴向撓性鉸練直徑14.25mm，感震質量（m)為 26.3g，經由ANSYS動態模擬分析得到χ軸與丫軸的共振 頻率同為93·126Ηζ。 為能進一步的瞭解感震結構的特性，故利用Ansys 分析感震結構於加逮度作用下的結構應力與角度變化情 形，因感震結構的兩軸特性相同，故只針對χ轴進行分析， 11 1272388 • 第七圖（”與❻)分別為X軸在加速度作用下的感震結構應 • 力圖與角度變化圖，由分析結果得知，感震結構在小於材 料降服應力的外力作用下，加速度與角度呈線性變化，因 此藉由角度的量測將可轉換成相對的加速度值。 本發明實施例中之雙軸向撓性鉸鍊(32)與感震質量 (31)於設計後，採精密線放電加工一體加工成型，且在感 震質量（31)下方黏置一片反射鏡(33)，再將螺絲(35)穿過透 • 孔（13)螺入雙軸向撓性鉸鍊(32)另一端的螺孔(34)内，固定 在基座（1)弟一固疋面（12)，將光學式二維角度量測裝置(？) 之里測探頭（21)與反射鏡(33)表面恰好切入在第六圖的線 性區域B位置，當基座（1)受到侧向振動的影響時，其感震 質I (31)將會產生角度擺動，藉由四象限光感測器（25)偵測 光束聚焦能量位置的輸出電壓，可求出感震質量(31)與基 座（1)間的實際角度擺動量，進而求得基座（1)的加速度二 於量測探頭（21)之角度的實際量測，係先將量測探頭 (21)固定於距反射鏡適當的位置，再將反射鏡每次偏轉固 定的角度後，觸發A/D資料擷取卡，抓取量測探頭的輸出 電壓號與反射面偏轉的角度，如此，可以得到反射面角 度與量測探頭(21)輸出電壓訊號的對應關係，如第八圖（a) 與(b)分別為X軸與Y軸量測結果，由圖中可以清楚地看 出曲線中間約有500 // rad的線性區段，本發明即利用此線 性區段作為基座（1)與感震質量(3丨)之間的相對角度量測。 對於本發明雙轴向光學式加速度計的整體實驗裝 12 1272388 置’如弟九圖所示，其中使用phySik Instrumente〔 PI〕公 •司所生產之二軸奈米定位平台〔model number PI_762.3L〕 (e)的X軸與Y軸為振動源，實驗中使用fft Analyzer〔 B&K， model 3560C〕（c)輸出激振訊號，經pi功率放大器（d)將激 振訊號放大後驅動奈米定位平台運動，而雙軸向光學式 加速度計（f)與參考加速度計（g)放置於奈米定位平台卜)的 上面’安裝時，兩加速度計⑴、（g)的感測方向必須和激振 • 源方向相同，最後將雙軸向光學式加速度計⑴與參考加速 度計（g)的輸出訊號透過FFT Analyzer(c)進行分析。 由於雙軸向光學式加速度計（f)的共振頻率除了可作 為頻率響應範圍的設計依據外，更可提供所量測得到之感 震質量的相對角度，要進一步換算成振動結構作用於基座 之加速度時的重要數據，而為了求得雙轴向光學式加速度 計⑴的共振頻率，使用FFT Analyzer(c)輸出掃聪式正弦波 訊號，經PI功率放大器（d)將訊號放大後驅動奈米定位平台 鲁 （e)運動，使安裝於奈米定位平台（e)上方的雙軸向光學式加 速度計⑴與參考加速度計(g)做相同的運動，將雙軸向光學 式加速度計（f)的輸出訊號與參考加速度計(g)輸出的加速 度訊號轉換為位移訊號後，由FFT Analyzer(c)每隔0·25Ηζ 記錄下雙軸向光學式加速度計（f)與參考加速度計（g)的振 幅比，繪製成第十圖所示，由第十圖（a)(b)中得知雙軸向光 學式加速度計X軸與Y轴的共振頻率分別為92·75Ηζ與 92·875Ηζ。 13 1272388 加速度計的電壓輸出與機械力的比值稱為靈敏度，其 輪出通常以電壓〔或電荷〕每單位重力加速度〔在海平面 緯度45度時為9.购m/s2〕來表心錄㈣量測通常是 使用固定頻率之正弦波源作為激振源，在__定的頻 率為100Hz’大部分的歐洲國家則選用16〇Hz。因其頻率1272388, Nine, invention description: • [Technical field to which the invention belongs]. The present invention relates to a biaxial optical accelerometer, and more particularly to an industrial development that can be applied to fineness, to effectively measure mechanical vibration, and the trouble caused by the vibration of the solution, thereby achieving accurate measurement. The purpose of the amount of vibration. [Prior Art] In recent years, due to the improvement of mechanical power and speed function, it is more important for precision measurement in precision industrial development due to the influence of mechanical reduction and mechanical vibration. In terms of technology, the main technical difficulty lies in the design of sensing technology and control mechanism, and the characteristics of the entire main = vibration isolation system have a relationship with the design of sensing technology and control mechanism. The vibration frequency generated by the person walking on the floor 2 is in the range of 1~he, and the pulsation of the earth is generally at 0.1 • 1 GHz. Therefore, in recent years, the design of the vibration damping system for precision mechanical equipment requires the preparation of the vibration isolation frequency capacity below 1 Hz. That is, the dynamometer of the accelerometer used must be suitable for low-frequency measurement, and even the vibration close to the sinking frequency can be measured. ...the accelerometer is a vibration measuring instrument with a measuring acceleration. Generally, the simplest design' is to record the relative motion between the internal shock mass of the accelerometer and its base by the sensor, and then obtain the acceleration of the pedestal. This sense is 'at the current stage, using capacitive sensors, · T, piezoelectric (10) T) sensors and strain gauges to design 'in recent years, with the optical fiber communication technology into 2388 degrees ^ system = this With the fiber as the sensing, the optical acceleration is achieved. The first US patent number usPat.NG.5,837,998 reveals that the fiber is fixed by the external A 'heart 孑 beam method, when the acceleration acts on the sensor structure. When the vibration of your shift is caused to bend, a light sensor is used to detect the beam energy to calculate the acceleration value acting on the sensor structure. Since the accelerometers implemented by the optical 2 sensor are expensive, they are rarely used in the industry. [Invention] The present invention has a construction cost of a conventional force velocity measuring instrument, which is high in manufacturing cost and insufficient in precision, and has many disadvantages in use. Therefore, the present invention provides a two-axis oblique optical acceleration. The tenth is that the optical two-dimensional angle measuring device and the sensing device are respectively fixed on the pedestal, and the optical two-dimensional angle measuring device is provided with a measuring probe, and the sensation is provided Biaxial flexible hinge, biaxial flexible hinge - with shock-sensing mass at the end. 'Sensing mass is equipped with a mirror; when the base is vibrated, 'the shock mass ^: will produce an angular swing' and The relative motion between the pedestals is utilized. The light source of the measuring probe can be projected onto the mirror of the seismic mass, and the reflected light on the mirror is used for beam focusing energy position signal processing to judge the seismic mass and the measuring probe. The relative motion between the two increases the acceleration of the pedestal. The embodiment of the invention has the following advantages: 1. The invention utilizes an optical two-dimensional angle measuring device, the optical measuring method has a very high angle measurement resolution, and is not easily affected by environmental factors 1272388 [eg: capacity The optical measurement characteristics of triboelectric noise, electromagnetic interference, humidity, temperature change, etc., to record the relative motion between the internal shock mass of the accelerometer and the pedestal, thereby obtaining the acceleration of the pedestal, and its overall design It's simpler than current accelerometers and easier to make. 2. The shock sensing device of the present invention adopts a biaxial flexible hinge design, and a deformation type shock-sensing structure developed by a flexible hinge instead of a ball joint, utilizes frictionless heat generation between the structures and can be integrated The advantages of processing and molding, so that the accuracy of the shock has been significantly improved. The design of the biaxial flexible hinge shock-sensing structure can design the geometry of the biaxial flexible hinge for selecting a specific measurement bandwidth, and convert the elastic support k value and the coupled seismic mass m value. Then, the measuring probe records the relative motion between the seismic mass and the pedestal, and indirectly determines the pedestal acceleration. Therefore, a low-cost, high-sensitivity optical accelerometer can be designed for a specific measurement bandwidth. ® Combining the advantages mentioned above, the biaxial optical accelerometer of this creation is a practical creation for today's increasingly demanding precision. In order to give your reviewers a deeper understanding of the content and function of the authoring device, the drawings and symbolic comparisons in this creation are listed below, and the illustrations are accompanied by the illustrations in the detailed description of the embodiments. [Embodiment] First, referring to the first, second and third figures, the biaxial optical 7 1272388 of the present invention, the speedometer, comprises: _ a base (1) provided with a first fixing surface (11) And at a suitable distance from the first fixed surface, a second fixing surface (12) is provided, and the second fixing surface (12) is provided with a through hole (13). The optical two-dimensional angle measuring device (2), as shown in the fourth figure, is fixed on the first fixing surface (11) of the base (1), the optical two-dimensional angle measuring device (2) There is a measuring probe (21), and the internal part of the measuring probe (21) is provided with a diode laser (22), a beam splitter (23), a collimating mirror (24), and a four-quadrant light. Sensor (25) [f〇ur_quadrant photo detector]. a seismic sensing device (3) fixed to a second fixing surface (12) of the base (1), the sensing device (3) being provided with a biaxial flexible hinge (32), the biaxial The flexible hinge (32) has a screw hole (34) at the end for the screw (35) to be screwed through the through hole (13) of the second fixing surface (12) of the base (1), and The other end of the axial flexible hinge (32) is provided with a seismic mass (31), and a mirror (33) is fixed to the bottom portion of the seismic mass (31), whereby the optical two-dimensional angle measuring device (2) The light source can be projected onto the mirror (33) at the bottom of the seismic mass (31). When the susceptor (1) is subjected to lateral vibration, the seismic mass (31) will be angularly oscillated, with the pedestal (1) A relative motion is generated between the optical two-dimensional angle measuring device (2) to detect the reflected light on the mirror (33) for beam focusing energy position signal processing. When the embodiment of the present invention is used, as shown in the third figure, the sensing device (3) is fixed above the base (1), and the optical two-dimensional angle measuring device (2) is fixed in the sense On the pedestal (1) below the seismic mass (31), the optical two-dimensional angular amount 8 1272388, and the measuring probe (21) of the measuring device (2) can project the laser beam to be fixed to the sensible mass. On the surface of the lower mirror (33), the reflected light from the mirror (33) is projected onto the four-quadrant light sensor (25) of the optical two-dimensional angle measuring device (2), when the base (1) is placed When placed on any object to be tested, it is affected by the lateral vibration of the object to be tested. [The seismic mass (31) will produce an angular oscillation, and a beam focusing energy is measured via a four-quadrant light sensor (25). The position signal (ie, the four quadrants (π+πι)·(ι +r\〇= 0 γ and + Πμ m+IV) = 0χ], after the circuit is processed, the signal is vibrated by the spectrum analyzer. analysis. The projection beam of the measuring probe (21) is directed by the diode laser (22) to the beam splitter (23) [as shown in the fourth figure], and the laser beam passes through the beam splitter (23). The collimating mirror (24) projects a parallel beam onto the mirror (33), and the reflected beam is projected through the collimating mirror (24) and the beam splitter (23) to the four-quadrant photosensor (25). )on. The invention adopts the laser collimation measurement method on the principle of optical measurement, and the so-called laser collimation measurement method refers to when the optical axis of the laser beam is aligned with the four-quadrant light sensor (25). The output voltages of the four photosensors are all the same. When the beam is deflected, the four sensors will exhibit different output voltage values. This different output voltage value can be used to measure the seismic mass ( 31) The angle yaw situation, so when the seismic mass (31) has no angular yaw, the reflected light passing through the collimator (24) and the beam splitter (23) will be in the center of the four-quadrant light sensor (25). The position forms a circular area. When the seismic mass (31) is angularly yawed, the reflected light passing through the collimating mirror (24) and the beam splitter (23) will be non-centered in the four-quadrant light sensor (25). The position forms a circular area. 9 Ϊ272388 Take the 6»X axial angle change as an example. When the mirror (33) is yawed as shown in the fourth figure + Θ X angle, the reflected light from the collimating mirror (24) and the beam splitter (23) will be focused. The four-quadrant light sensor (25) forms a spot position as shown in FIG. 5A, and the four-quadrant light sensor (25) signal is processed by a self-made beam focusing energy processing circuit to be a positive voltage output when the mirror is used as a mirror. (33) in the fourth picture without 6> χ angle yaw 'reflected light in the four-quadrant light sensor (25) will form the spot position as shown in the fifth figure, four-quadrant light sensor (25) signal The beam focusing energy _ is zero voltage output after the processing circuit. When the mirror (33) is yawed at an angle as shown in the fourth figure, the reflected light forms a light as shown in Fig. 5-C in the four-quadrant photo sensor (25). At the point position, the four-quadrant light sensor (25) signal is processed by the beam focusing energy signal processing circuit and is a negative voltage output. Therefore, the curve shown in the sixth figure is an angular yaw and a four-quadrant light sensor (25) signal. Round-out relationship [Graphic X-axis is the measurement of the surface deflection angle change, and the Υ axis is the beam focus energy limit number output]' The six maps Β, Β and C respectively correspond to the three signal processing patterns a, _ B and C in the fifth graph, and the linear region in the sixth graph curve can be used as the angle measurement, which is excellent for both dynamic and static characteristics. Measurement tool. Since the vibration frequency generated by the general laboratory staff walking on the floor is in the range of 1 to 3 Hz, the pulsation of the earth is generally in the range of 〇1~ι〇Ηζ. Therefore, in recent years, the design of the vibration damping system for the nanometer measuring instrument table needs to have the vibration isolation frequency capability below 1 Hz, that is, the accelerometer used must be suitable for low frequency measurement, so the invention The manner of the embodiment is described with respect to a low frequency accelerometer. In order to further complete the biaxial optical accelerometer, the designed .1272388 must have a biaxial motion function. In order to achieve this function, it is also necessary to use a variable shock sensing structure design method. An axially flexible hinge to miniaturize the joint of the structure, using the difference in material stiffness to simulate the characteristics of the desired joint, and the difference in material stiffness is determined by the geometry of the material. In the design of seismic structure, if the design of different accelerometer resonance frequencies is different, the frequency response will be different. In practical applications of accelerometers, it is generally necessary to design the required frequency response for the applied field. • The invented biaxial optical accelerometer embodiment is based on the measurement of ground pulsation (0.1 to 10 Hz). Therefore, in the case of low damping ratio design, the frequency response is taken as 10% of the system resonance frequency. basics of design. Therefore, the desired accelerometer resonance frequency should be around 100 Hz. Firstly, the geometric parameters of the two-dimensional seismic structure were analyzed with ANSYS 8.0 to establish a 3D geometric model. The element type was analyzed by using the 8-node Solid 45 hexahedral element as the element type. In the theoretical analysis, the shock-absorbing structure material is S304 stainless steel, and the material has a Young's modulus (Y〇ung, s Lu modulus) of 193 Gpa and a mass density of 7860 kg/m3. The length, width and height of the shock-absorbing structure are 15mm, l5mm, 34mm respectively. The biaxial flexible hinge diameter is 14.25mm, and the seismic mass (m) is 26.3g. The axis and the 丫 axis are obtained by ANSYS dynamic simulation analysis. The resonance frequency is the same as 93·126Ηζ. In order to further understand the characteristics of the seismic structure, Ansys is used to analyze the structural stress and angle change of the seismic structure under the action of the acceleration. Because the two-axis characteristics of the seismic structure are the same, it is only analyzed for the χ axis. 11 1272388 • The seventh figure ("and ❻") is the seismic structure of the X-axis under acceleration. The force diagram and the angle change diagram are obtained. According to the analysis results, the seismic structure is under the external force less than the material's surrender stress. The acceleration and the angle change linearly, so the measurement of the angle can be converted into a relative acceleration value. In the embodiment of the invention, the biaxial flexible hinge (32) and the seismic mass (31) are designed and adopted. Precision wire electrical discharge machining is integrally formed, and a mirror (33) is placed under the seismic mass (31), and the screw (35) is screwed through the through hole (13) into the biaxial flexible hinge (32). The screw hole (34) at the other end is fixed to the base (1) of the base (1), and the probe (21) and the mirror of the optical two-dimensional angle measuring device (?) are 33) The surface just cuts into the linear region B position in the sixth figure, when the base 1) When the lateral vibration is affected, the seismic mass I (31) will produce an angular oscillation, and the four-quadrant light sensor (25) detects the output voltage of the beam focusing energy position, and the sensing is obtained. The actual angular swing between the mass (31) and the pedestal (1), and then the actual measurement of the acceleration of the pedestal (1) and the angle of the measuring probe (21), the measuring probe (21) Fixing at an appropriate position from the mirror, and then deflecting the mirror at a fixed angle each time, triggering the A/D data capture card to capture the angle of the output voltage of the measurement probe and the deflection of the reflective surface. The corresponding relationship between the angle of the reflecting surface and the output voltage signal of the measuring probe (21) is obtained. For example, the eighth graphs (a) and (b) respectively measure the X-axis and the Y-axis, and the middle of the curve can be clearly seen from the graph. With a linear segment of about 500 // rad, the present invention utilizes this linear segment as a relative angular measurement between the pedestal (1) and the seismic mass (3 丨). For the biaxial optical acceleration of the present invention The overall experimental setup of the meter 12 1272388 is set as shown in the figure of the nine, using phySik Instrumente [ PI The two-axis nano positioning platform (model number PI_762.3L) produced by the company (e) is the vibration source of the X-axis and the Y-axis. The experiment uses the fft Analyzer [B&K, model 3560C] (c) output excitation. The vibration signal, the pi power amplifier (d) amplifies the excitation signal to drive the nano positioning platform motion, and the biaxial optical accelerometer (f) and the reference accelerometer (g) are placed on the nano positioning platform) In the above installation, the sensing directions of the two accelerometers (1) and (g) must be the same as the direction of the excitation and source. Finally, the output signals of the biaxial optical accelerometer (1) and the reference accelerometer (g) are transmitted through the FFT Analyzer ( c) Perform an analysis. Since the resonant frequency of the biaxial optical accelerometer (f) can be used as a design basis for the frequency response range, it can also provide the relative angle of the measured seismic mass, which is further converted into a vibration structure acting on the base. In order to obtain the resonance frequency of the biaxial optical accelerometer (1), the FFT Analyzer (c) is used to output the sinusoidal sine wave signal, and the signal is amplified by the PI power amplifier (d) to drive the 奈The meter positioning platform Lu (e) motion enables the biaxial optical accelerometer (1) mounted above the nano positioning platform (e) to perform the same motion as the reference accelerometer (g), and the biaxial optical accelerometer ( After the output signal of f) and the acceleration signal output by the reference accelerometer (g) are converted into displacement signals, the biaxial optical accelerometer (f) and the reference accelerometer are recorded by the FFT Analyzer (c) every 0·25Ηζ ( The amplitude ratio of g) is shown in the tenth figure. It is known from the tenth figure (a)(b) that the resonance frequencies of the X-axis and the Y-axis of the biaxial optical accelerometer are 92·75Ηζ and 92·, respectively. 875Ηζ. 13 1272388 The ratio of the voltage output of the accelerometer to the mechanical force is called the sensitivity. The rounding is usually recorded by the voltage [or electric charge] per unit of gravity acceleration [9. m/s2 at sea level latitude 45 degrees]. (4) The measurement usually uses a sine wave source with a fixed frequency as the excitation source, and the frequency of __ is 100 Hz. In most European countries, 16 Hz is used. Because of its frequency
值與電力系統頻率及共振頻率相差很多，可避免受其干 擾。再者’在SI單位系統中，160Hz〔實際上是159 i59Hz〕 為lOOOmdians/s，對於整合其他量測均具有特殊的意義。 由於本發明的雙軸向光學式加速度計乃針對量測大 地脈動〔earth’s crust movement〕為設計基礎，故實驗中採 用固定單一頻率10Hz的正弦波作為激振訊號，實驗架設如 第九圖所示，於改變奈米定位平台（e)的輸出振幅（1〜5〇um) 下，同日$ S己錄出參考加速度計(g)的加速度值與雙轴向光學 式加速度計(f)的電壓輸出值，如第十一圖所示，由圖中（&) 與(b)可得雙轴向光學式加速度計的X軸與γ軸靈敏度分別 為22.94V/g與21.28V/g。圖中更清楚顯示出雙軸向光學式 加速度計具有極佳的量測線性度，因此藉由此極佳線性度 的特性，結合第八圖所得500//rad線性量測範圍内χ軸與γ 軸所對應的士 4.55V與士4.32V電壓訊號值，可大概估計出X軸 與Y軸最大加速度量測範圍分別約為〇·2 peak(4 55/22.94) 與〇.2gpeak(4.32/21.281) 〇 l2^2388 頻率響應是指加速度計在數個頻率範圍内，戶斤量消X寻 到之對應某個參考頻率點的輸出。頻率響應通常取決於已 知的靈敏度。頻率響應常見的量測方式有以下三種：（1) 在點對點的對應基準之下，使用正弦波激振；（2)在半連續 隨方法時’可以使用掃瞎式正弦波；（3)或於連續性方法 ’送一個漫散訊號（Ran(J0msignal)給激振源，即可緣 出頻率響應圖。 ® 實驗架設如第九圖所示，於實際量測使用半連續性方 法’使用FFTAnalyzer(c)輸出0.5〜30Hz之掃瞄式正弦波 訊號，經PI功率放大器（句將此訊號放大後驅動奈米定位 平台（e)運動’同時設定奈米定位平台（e)具有固定50 um的 位移振幅輸出。將雙軸向光學式加速度計⑴的輸出訊號藉 由第十一圖之靈敏度數值轉換為加速度值後，由FFT Analyzer(c)以每隔〇·5Ηζ同步地記錄下參考加速度計⑻與 φ 雙輛向光學式加速度計(f)的加速度值，如第十二圖所示， 由圖（a)與(b)中可得χ軸與γ軸量測操作頻率小於21Hz 之下’參考加速度計(g)與雙軸向光學式加速度計⑴的加速 度值具有較佳的線性關係。 雙軸向光學式加速度計⑴的雜訊來源除了與電路設計 中所採用的電子元件與OP放大器（OP amplifiers)有密切關 係外’二極體雷射受環境溫度變化而造成光電流訊號的變 動為一主要的訊號雜訊來源，本發明除選擇超低雜訊電子 70件與0P放大器作為系統的電路設計外，更設計一自動光 15 1272388 功率控制（Automatic Power Control, APC)電路控制雷射 輸出的穩定性。 針對本發明所研製而成的雙轴向光學式加速度計⑴， 關掉奈米定位平台（e)的電源使其靜止不動時，利用FFT Analyzer(c)記錄下雙軸向光學式加速度計（f)的輸出電壓， 並經由第十一圖之靈敏度數值計算出等效加速度雜訊(N〇ise equivalent acceleration，ΝΕΑ)頻譜密度，如第十三圖（a)與(b)所示 • 為實驗的結果，由圖得知本發明所完成雙轴向光學式加速 度計⑴的電路設計系統，X軸與γ軸同於5〇Hz下具有小於30 // g/VHz的電氣雜訊。 綜合以上所述，本發明採用光學準直量測方法具有極 高角度量測解析度與不易受到環境因素影響的光學量測 特性，提兩雙轴向光學式加速度計⑴整體的量測精度。於 感震裝置(3)上採用簡易式的雙軸向撓性鉸鍊(32)設計，改 進了先前技術製作上的困難度及設計複雜度，且可針對選 _ 擇一特疋1測頻寬來設計雙軸向撓性鉸鍊(3 2)的幾何形 狀，於換鼻出雙軸向撓性鉸鍊(32)之彈性支承k值與搭配 感震質量m值後，將能於特定量測頻寬範圍下作精密的加 速度量測。因此本發明確具有新穎性與實用性，量測方法 具獨特性，應符專利巾請要件，妥於法提出申請。 【圖式簡單說明】 弟一圖·係為本發明之立體分解圖。 16 1272388 - 第二圖：係為本發明之立體組合圖。 . 第三圖：係為本發明之側視圖。 第四圖：係為本發明量測探頭之構造示意圖。 第五圖：係為本發明四象限光感測器之訊號處理示意圖。 第六圖：係為本發明量測曲線之示意圖。 第七圖：係為本發明ANSYS分析二維感震結構結果圖。 第八圖：係為本發明量測曲線實驗數據。 φ 第九圖：係為本發明雙軸向光學式加速度計整體實驗示 圖。 第十圖：係為本發明之自然頻率測試圖。 第十一圖：係為本發明之低頻加速度響應示意圖。 第十二圖：係為本發明之頻率響應（操作頻率範圍 0·5〜30HZ)。 第十三圖··係為本發明之雜訊所等效的加速度示意圖。 *【主要元件符號說明】 (1) 基座 （11)第一固定面 (12) 第二固定面 （13) 透孔 (2) 光學式二維角度量測裝置 (21) 量測探頭 （22)二極體雷射 (23) 分光鏡 （24)準直鏡 (25)四象限光感測器 （3)感震裝置 (31)感震質量 （32)雙軸向撓性鉸鍊 17 1272388The value is much different from the power system frequency and the resonant frequency to avoid interference. Furthermore, in the SI unit system, 160 Hz (actually 159 i59 Hz) is lOOOmdians/s, which has special significance for integrating other measurements. Since the biaxial optical accelerometer of the present invention is designed for measuring the earth's crust movement, a sine wave with a fixed single frequency of 10 Hz is used as the excitation signal in the experiment, and the experimental setup is as shown in the ninth figure. Under the change of the output amplitude (1~5〇um) of the nano positioning platform (e), the acceleration value of the reference accelerometer (g) and the voltage of the biaxial optical accelerometer (f) are recorded on the same day. The output values, as shown in Fig. 11, are obtained by (&) and (b), and the X-axis and γ-axis sensitivities of the biaxial optical accelerometer are 22.94 V/g and 21.28 V/g, respectively. It is clearer in the figure that the biaxial optical accelerometer has excellent linearity of measurement, so the characteristics of the excellent linearity, combined with the amplitude of the 500//rad linear measurement range obtained in the eighth figure, The γ axis corresponds to the value of 4.55V and 4.32V voltage signal, which can roughly estimate the maximum acceleration measurement range of X-axis and Y-axis respectively 〇·2 peak(4 55/22.94) and 〇.2gpeak(4.32/ 21.281) 〇l2^2388 The frequency response refers to the output of the accelerometer in a number of frequency ranges. The frequency response usually depends on the known sensitivity. There are three common measurement methods for frequency response: (1) using a sine wave excitation under a point-to-point corresponding reference; (2) using a broom sine wave in a semi-continuous method; (3) or In the continuity method 'send a diffuse signal (Ran (J0msignal) to the excitation source, you can get the frequency response map. ® Experiment setup as shown in Figure IX, using the semi-continuous method for actual measurement' using FFTAnalyzer (c) Output a scanning sine wave signal of 0.5 to 30 Hz, which is driven by a PI power amplifier (this signal is amplified to drive the nano positioning platform (e) movement] and the nano positioning platform (e) is fixed at 50 um. Displacement amplitude output. After the output signal of the biaxial optical accelerometer (1) is converted into the acceleration value by the sensitivity value of the eleventh figure, the reference accelerometer is recorded synchronously by the FFT Analyzer (c) every 〇·5Ηζ. (8) Acceleration value of φ dual-vehicle optical accelerometer (f), as shown in Fig. 12, the operating frequencies of the χ-axis and γ-axis measured in Figures (a) and (b) are less than 21 Hz. 'Reference accelerometer (g) and biaxial optical The acceleration value of the accelerometer (1) has a better linear relationship. The noise source of the biaxial optical accelerometer (1) is not only related to the electronic components and OP amplifiers used in the circuit design, but also the 'diode body. The change of the photocurrent signal caused by the change of the ambient temperature is a major source of signal noise. In addition to selecting the ultra-low noise electronics 70 and the 0P amplifier as the circuit design of the system, the design of an automatic light 15 1272388 The power control (APC) circuit controls the stability of the laser output. For the biaxial optical accelerometer (1) developed by the present invention, the power supply of the nano positioning platform (e) is turned off to be stationary. The FFT Analyzer (c) is used to record the output voltage of the biaxial optical accelerometer (f), and the equivalent acceleration noise (ΝΕΑ) spectrum is calculated from the sensitivity value of the eleventh figure. Density, as shown in Fig. 13 (a) and (b) • For the results of the experiment, the circuit of the biaxial optical accelerometer (1) completed by the present invention is known from the figure. The system has an X-axis and a γ-axis with electrical noise of less than 30 // g/VHz at 5 Hz. In summary, the present invention uses an optical collimation measurement method with extremely high angle measurement resolution and The optical measurement characteristics that are not easily affected by environmental factors, and the measurement accuracy of the two dual-axis optical accelerometers (1) are adopted. The simple biaxial flexible hinge (32) is designed on the seismic sensing device (3). The difficulty in designing the prior art and the design complexity are improved, and the geometry of the biaxial flexible hinge (32) can be designed for the selection of the width of the special width 1 (2 2). The elastic support k value of the flexible hinge (32) and the m-value of the seismic mass can be used to make precise acceleration measurements under a specific measurement bandwidth. Therefore, the present invention has novelty and practicability, and the measuring method is unique, and should be in accordance with the requirements of the patented towel, and the application is properly made. [Simple description of the drawing] The first figure is a perspective exploded view of the present invention. 16 1272388 - Second figure: is a three-dimensional combination of the present invention. Third Figure: is a side view of the invention. The fourth figure is a schematic diagram of the construction of the measuring probe of the present invention. The fifth figure is a schematic diagram of the signal processing of the four-quadrant light sensor of the present invention. Figure 6 is a schematic diagram of the measurement curve of the present invention. Figure 7 is a result of analyzing the two-dimensional seismic structure of ANSYS. The eighth figure is the experimental data of the measurement curve of the present invention. φ Ninth diagram: It is the overall experimental diagram of the biaxial optical accelerometer of the present invention. Figure 10 is a natural frequency test chart of the present invention. Figure 11 is a schematic diagram of the low frequency acceleration response of the present invention. Figure 12: The frequency response of the present invention (operating frequency range 0·5 to 30HZ). The thirteenth image is an equivalent acceleration diagram of the noise of the present invention. *【Main component symbol description】 (1) Base (11) First fixed surface (12) Second fixed surface (13) Through hole (2) Optical two-dimensional angle measuring device (21) Measuring probe (22 ) Diode laser (23) Beam splitter (24) Collimating mirror (25) Four-quadrant light sensor (3) Sensing device (31) Sensing mass (32) Biaxial flexible hinge 17 1272388
(33) 反射鏡 （34)螺孔 (35)螺絲 （c) FFT Analyzer (d) PI功率放大器 （e)奈米定位平台 (f)雙軸向光學式加速度計（g)參考加速度計 18(33) Mirror (34) screw hole (35) screw (c) FFT Analyzer (d) PI power amplifier (e) nano positioning platform (f) biaxial optical accelerometer (g) reference accelerometer 18