200419134 ；：；;；;：:f；^:|：^i；：^;：!:：i：i;：:：^；::|i!!i：：：f：i：gf 【發明所屬之技術領域】 本發明係關於一種五自由度環型光柵式旋轉軸量測系 統，特別是指一種將量測光學原件微組化，俾能同時測量到 工具機主軸之偏擺量、位移量及主軸轉速等五個自由度之訊 號，提高精密加工與量測技術的量測系統。 【先前技術】 現今數值工具機在加工與量測技術的發展上已經日趨 成熟，許多的量測定位已達到微米或奈米等級，但很多精密 量測機具亦因本身精度過高而對許多的偏差變得相當地敏 感。在一個精密量測的過程中，其本身包函了相當多誤差因 素，例如量具本身的誤差、工件本身誤差與量測平台本身的 誤差……等等，這些誤差都是會對我們往後在研究或生產方 面帶來不小的衝擊，也是造成產業無法升級的重要因素，也 正因如此，改善這些誤差的工作也就變得十分地重要。 上述所提及的誤差當中，就以平台誤差最為重要。因為 在精密定位量測之中，平台推動了整個量測的架構，對整個 量測過程而言，若平台產生了偏移，那整個系統就會因平台 偏移而有所誤差，即使量具本身精度夠高，但還是會因為平 台而影響其量測的結果。 平台本身的誤差方面恰好是以本身的自由度來計算，包 括：X、Υ、Ζ三個軸向誤差以及環繞三轴旋轉的偏擺誤差等 14 200419134 六個自由度。以目前而言，用來檢測平台六自由度誤差的技 術來說應是尚未成熟，坊間雖有許多聲稱可以量測出六自由 度誤差的儀器，但通常是過於誇大或價格昂貴，經常使人望 而卻步，貫非科技之福。針對此問題我們發明了一種以二維 光柵搭配光檢測器（pSD )之利用光波繞射原理造成入射與 反射角偏移，因而反推出光柵位移與平台三轴位移量與誤差 之關係，進而反推誤差大小的檢測方法。此技術實在可視為 檢測技術上的一大突破，也可較一般檢測技術還精確且更細 微。 【發明目的] 本餐明之目的即在於提供一種以二維光學尺作六自由 度量測的系統，係以二維光柵搭配光檢測器利用光波繞射原 理造成入射與反射角偏移，因而反推出光柵位移與平台三軸 位移量與誤差之關係，較一般檢測技術還精確且更細微。 【内容】 乂目Θ現有的工具機量測來說，一般對於主軸的偏擺與 疋位誤差方面，皆是採取了光源直接打在旋轉主軸上，然後 利用主軸上的一些光接收器來擷取光源訊號，進而對所接收 之Λ说進行訊號處理的工作。以這樣的方式來作量測工作， 所月b得到的精度往往有限，有時還會因量測系統的架設造成 些决差上的問題。所以，為求一勞永逸，我們設計了一種 15 200419134 利用二維反射式光柵對主軸進行六自由度檢測的方法，以簡 單、方便且精確為訴求，期望能為量測方法上帶來―種新的 創新。200419134;: ;;;; :: f; ^: |: ^ i;: ^;:! :: i: i; ::: ^; :: | i !! i ::: f: i: gf 【 The technical field to which the invention belongs] The present invention relates to a five-degree-of-freedom ring-type grating-type rotating shaft measurement system, and particularly to a micro-assembly of measurement optical elements, which can simultaneously measure the deflection of the machine tool spindle, Signals of five degrees of freedom, such as displacement and spindle speed, improve the measurement system of precision machining and measurement technology. [Previous technology] Nowadays, numerical tool machines have become more mature in the development of processing and measurement technology. Many measurement positions have reached the micron or nanometer level. However, many precision measurement tools are also very sensitive to many because of their high accuracy. Bias becomes quite sensitive. In a precise measurement process, it contains a lot of error factors, such as the error of the measuring tool itself, the error of the workpiece itself and the error of the measurement platform itself, etc. These errors will affect us in the future. Research or production has brought a lot of impact, which is also an important factor that prevents the industry from upgrading. Because of this, the work to improve these errors has become very important. Of the errors mentioned above, platform errors are the most important. Because in the precise positioning measurement, the platform promotes the entire measurement architecture. For the entire measurement process, if the platform is offset, the entire system will have errors due to the platform offset, even if the gage itself The accuracy is high enough, but it still affects the measurement results due to the platform. The error of the platform itself is calculated by its own degrees of freedom, including: three axial errors of X, Υ, and Z, and yaw errors of rotation around three axes. 14 200419134 Six degrees of freedom. At present, the technology used to detect the six-degree-of-freedom error of the platform should be immature. Although there are many instruments that claim to measure the six-degree-of-freedom error, they are usually too exaggerated or expensive, and often make people Staying away is not the blessing of science and technology. In response to this problem, we have invented a two-dimensional grating with a photodetector (pSD) that uses the principle of light diffraction to shift the angle of incidence and reflection, so the relationship between the grating displacement and the three-axis displacement and error of the platform is deduced, and Detection method of the magnitude of the push error. This technology can be regarded as a major breakthrough in detection technology, and it can also be more precise and more detailed than the general detection technology. [Objective of the Invention] The purpose of the present invention is to provide a six-dimensional measurement system using a two-dimensional optical ruler. A two-dimensional grating is used in combination with a light detector to utilize the principle of light wave diffraction to shift the incident and reflection angles. The relationship between the grating displacement and the three-axis displacement and error of the platform is introduced, which is more accurate and subtle than the general detection technology. [Content] For the measurement of the existing machine tools of Θ, generally, for the deflection and position error of the main shaft, the light source is directly hit the rotating main shaft, and then some light receivers on the main shaft are used to capture it. Take the light source signal, and then perform signal processing on the received Λ. When the measurement is performed in this way, the accuracy obtained by month b is often limited, and sometimes there are some serious problems due to the installation of the measurement system. Therefore, in order to get it done once and for all, we have designed a method for detecting six degrees of freedom of the main axis using a two-dimensional reflective grating. It is based on simplicity, convenience, and accuracy. It is expected to bring a new kind of measurement method. Innovation.
本發明係以雷射二極體當作光源，發射_雷射光於平台 的2D光柵上使其繞射’且平台旋轉，依照光柵繞射方式: 形成四條繞射光分別投射至反射鏡、分光鏡與二維光檢測器 上，並以反射鏡所反射之光投射到干涉鏡上，使得到兩道反 射光干v且利用光接收器來接收干涉後所得軸向偏差數 據。接著使用透過分光鏡分光後得到之穿透人射光角度差異 量來推算第三個軸向的偏差量’此外’在二維光檢測器上所 接收到的光還有分光後㈣直分光進行干涉過程的光，使用 光接收器接收干涉光可幫助我們瞭解軸向誤差。而利用穿透 的刀光就旎得到繞著三軸向旋轉的偏擺誤差。藉由結合上述The present invention uses a laser diode as a light source, and emits laser light on the platform's 2D grating to diffract it, and the platform rotates. According to the grating diffraction method, four diffracted lights are formed to be respectively projected onto a reflector and a beam splitter. And the two-dimensional light detector, and the light reflected by the reflector is projected onto the interferometer, so that the two reflected light stems v and the optical receiver is used to receive the axial deviation data obtained after the interference. Then use the amount of light transmitted through the beam splitter to calculate the difference in the third axial direction. In addition, the light received on the two-dimensional photodetector can be split after the beam is split. Process light. Using an optical receiver to receive interference light can help us understand axial errors. By using the penetrating knife light, the yaw error of rotation around three axes is obtained. By combining the above
六種偏差即可為六自由度誤差。 【實施方式】 如圖一所示，本發明係以雷射二極體di〇和） 2當作光源，發射一雷射光至干涉鏡組設備上，使其產生發 射光的第一道穿透光與反射光，再利用反射鏡5、0將穿透 光反射回干涉豸u上，使得穿透光又產生出另—道的反射 光（暫稱為第二次反射光），將第二次反射光與先前第一次 '乍差頻干涉’再由光接收器（Photo diodes)7接收其 16 200419134 位置變化，由此便可知主軸的z軸垂直度誤差了。 前述之第一次反射光射入平台的二維反射式光栅1上， 使其發生繞射現象，光栅繞射後可得四條正負等值、反向雙 重都卜勒一階光{(1，〇)、（〇，1)、（—1，〇)、（〇，_1) }， 其中（1，0)與（-1，0)光會直接投射在分光鏡3、4上， 以分光後的穿透光打在二維光檢測器（2D PSD ) 9、1 〇上， 使兩個二維光檢測器9、10分別接收到兩條穿透光的訊號， 藉由這兩個訊號的角偏移利用差頻干涉來推算平台偏擺的 角度與大小，如此再反算X、γ、z軸的分量即可瞭解繞各軸 旋轉量為多少，且依光檢測器9、1〇上穿透光的偏轉量可利 用正父訊號之解相位得知單軸向的誤差，如此我們即可得到 四個自由度的誤差了。 此外，另兩條光（0，1)與（0，—υ會先投射在兩個 反射鏡5、6上，再藉由反射原理將光打到干涉鏡u上，利 用干，步鏡11來產生一組干涉光，如此一來，在光接收器7 上就咸得到干涉光的訊號，且因平台轉動可再得另-組干涉 " 將兩組干涉條紋結果做誤差分析，即可得平台x軸得 :移块差。從這個訊號來得知平台因為旋轉而產生的單軸向 决差值。至於另一軸向（y軸向）誤差則是運用先前（1，〇)、 Μ纟分光後所之垂直分光來投射到最上端的干涉鏡 2上’―樣利用光的干涉作用使得光接收^ 8得到干涉訊 17 200419134 號，依此即可得y軸向的誤差了。 本發明運用到許多的光學鏡組，每一鏡組皆有其功能與 作用’以下為我們對光學鏡組的介紹： 1.反射鏡5、6 :用來將光源反射至所須的位置；反射鏡 不具有將光強度改變之功能。 2·为光鏡3、4:光源經過分光鏡之後會產生一道穿透光 與一道垂直穿透光之分光，經過分光之後的光源相位與先前 ，同，強度只原先的1 /2倍。 · 3·二維光柵1 : 一般光柵分為穿透式與反射式兩種，其 主要功能在於產生光波的繞射；雷射光束照設在光栅上會產 生繞射光，若光柵正在移動，則會因都卜勒效應，而使得各 階繞射光產生不同程度的頻移。 另外，文中有提到幾個光學名詞，亦說明如後： 1.%射（diffraction):繞射是光在障礙物附近，如狹 縫或針孔的邊緣發生，彎曲的現象，目此繞射現象可視· 為由無數同調（coherent)小光源相互干涉而成的。 2·干涉（interference) ··是由於兩個光波線性重疊而 引起的，若合成波的強度大於各別者稱為建設性干 涉，反之為破壞性干涉，基本上光的干涉都是由於電 和磁向量的加疊而引起。 3·都卜勒效應（Doppler ):當頻率f〇光源照在以速度v 18 200419134 移動的散射表面時，會產生])〇pp 1 er效應，使得表面 政射回來的光產生的頻率變化，可用下式表 示： △ f = fo(v/c)(cosal+cosa2)，其中： f〇 :入射光頻率， c :光速， v :散射表面的速度， α 1 :入射光與散射表面速度的夾角， 散射光與入射表面速度的夾角， 4·差頻干涉：入射光束經過光柵而產生繞射，利用簡單 的光學系統，使等值、反向雙重Dopp 1 er頻移的兩道 繞射光束結合，形成「差頻干涉」。 【特點及功效】 本發明以二維光栅搭配光檢測器利用光波繞射原理造成 入射與反射角偏移，因而反推出光柵位移與平台三軸位移量 與决差之關係，進而反推誤差大小，實在可視為檢測技術上 的一大突破’也可較一般檢測技術還精確且更細微。 上列洋細說明係針對本發明之一可行實施例之具體說 明，惟該實施例並非用以限制本發明之專利範圍，凡未脫離 本發明技藝精神所為之等效實施或變更，均應包含於本案之 專利範圍中。 19 200419134 【圖式簡單說明】 凊參閱以下有關本發明一較佳實施例之詳細說明及其附 圖，將可進一步瞭解本發明之技術内容及其目的功效；有關 該實施例之附圖為： 圖一為,本發明以二維光學尺作六自由度量測的系統之架 構例圖。 【主要部分代表符號】 1光柵 11、12干涉鏡 2雷射二極體 3、4分光鏡 5、6反射鏡 7、8光接收器 9 ' 10光檢測器Six kinds of deviations can be six degrees of freedom errors. [Embodiment] As shown in FIG. 1, the present invention uses a laser diode di0 and 2 as a light source, and emits a laser light to the interferometer group equipment to cause the first pass of the emitted light to pass through. Light and reflected light, and then use the reflecting mirrors 5, 0 to reflect the penetrating light back to the interference 豸 u, so that the penetrating light generates another channel of reflected light (tentatively called the second reflected light), and the second The secondary reflected light and the previous first 'differential frequency interference' are received by the photo diodes 7 to change its 16 200419134 position. From this, we can know the z-axis perpendicularity error of the main axis. The aforementioned first reflected light is incident on the two-dimensional reflective grating 1 of the platform to cause the diffraction phenomenon. After the grating is diffracted, four positive and negative equivalent, reverse double Doppler first-order lights {(1, 〇), (〇, 1), (-1, 0), (〇, _1)}, where (1, 0) and (-1, 0) light will be directly projected on the beam splitters 3, 4 to split the light The subsequent transmitted light hits the two-dimensional light detector (2D PSD) 9, 10, so that the two two-dimensional light detectors 9, 10 receive two signals of the transmitted light, respectively. With these two signals, The angular offset uses the frequency difference interference to estimate the angle and magnitude of the platform's deflection, so that the components of the X, γ, and z axes can be calculated by inverse calculation, and the amount of rotation around each axis can be known. The amount of deflection of the upper penetrating light can be used to determine the uniaxial error by the solution phase of the positive father signal, so we can get the error of four degrees of freedom. In addition, the other two lights (0, 1) and (0, —υ will be projected on the two mirrors 5, 6 first, and then the light will be hit on the interferometer u by the principle of reflection. To generate a set of interference light. In this way, the signal of the interference light is obtained on the optical receiver 7, and another set of interferences can be obtained due to the rotation of the platform. The platform's x-axis is: the block shift. From this signal, we know the uniaxial determination of the platform's rotation due to rotation. As for the other axial (y-axis) error, the previous (1, 0), M垂直 The vertical beam split after the beam splitting is projected onto the uppermost interfering mirror 2 --- the interference of light is used to make the light receiving ^ 8 get the interference signal 17 200419134, and the y-axis error can be obtained according to this invention Many optical lens groups are used, each of which has its function and function. 'The following is our introduction of optical lens groups: 1. Mirrors 5, 6: used to reflect the light source to the required position; mirror It does not have the function of changing the light intensity. 2 · For light mirrors 3 and 4: The light source passes through the beam splitter. There will be a split of a penetrating light and a vertical penetrating light. The phase of the light source after splitting is the same as before, and the intensity is only 1/2 times of the original. · 3 · Two-dimensional grating 1: General grating is divided into transmissive The main function of the two types is to generate the diffraction of light waves. The laser beam on the grating will generate diffracted light. If the grating is moving, it will cause different levels of diffracted light due to the Doppler effect. In addition, there are several optical terms mentioned in the text, which are also explained as follows: 1.% diffraction: Diffraction is the phenomenon where light is near the obstacle, such as the edge of a slit or pinhole, and it is bent. At this point, the diffraction phenomenon can be seen as being caused by the interference of numerous small coherent light sources. 2. Interference is caused by the linear overlap of two light waves. If the intensity of the combined wave is greater than the respective This is called constructive interference, otherwise it is destructive interference. Basically, the interference of light is caused by the superposition of electric and magnetic vectors. 3. Doppler effect: When the frequency f0 light source shines at speed v 18 200419134 The moving scattering surface will produce]) 〇pp 1 er effect, so that the frequency change of the light emitted by the surface can be expressed by the following formula: △ f = fo (v / c) (cosal + cosa2), where: f〇: frequency of incident light, c: speed of light, v: velocity of scattering surface, α1: angle between incident light and velocity of scattering surface, angle between scattered light and velocity of incident surface, 4 · differential frequency interference: incident light beam passes through grating Diffraction is generated, and a simple optical system is used to combine two diffractive beams with equal and reverse Dopp 1 er frequency shifts to form "differential frequency interference". [Features and effects] The present invention uses a two-dimensional grating with a light detector to use the principle of light diffraction to shift the angle of incidence and reflection, so the relationship between the grating displacement and the three-axis displacement of the platform and the difference is deduced, and the magnitude of the error is further deduced. It can be regarded as a breakthrough in detection technology. It can also be more precise and more detailed than the general detection technology. The above detailed description is a specific description of a feasible embodiment of the present invention, but this embodiment is not intended to limit the scope of the patent of the present invention. Any equivalent implementation or change that does not depart from the technical spirit of the present invention should include Within the scope of the patent in this case. 19 200419134 [Brief description of the drawings] 凊 Please refer to the following detailed description of a preferred embodiment of the present invention and the accompanying drawings to further understand the technical content of the present invention and its purpose and effect; the drawings related to this embodiment are: FIG. 1 is a diagram illustrating an example architecture of a system for six-free measurement using a two-dimensional optical ruler according to the present invention. [Representative symbols of main parts] 1 grating 11, 12 interferometer 2 laser diode 3, 4 beam splitter 5, 6 reflector 7, 8 light receiver 9 '10 light detector
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