Autocollimation自動測量

                                                   北京正科科技有限公司測量儀器部

自動測量：

It is the system used by all preset manufacturers to measure in a very quick way.

自動測量是所有的制造商用來快速測量的方式丽惭。

Unfortunately it is the less precise either for accuracy, for repeatability and for reproducibility.

然而岗仑，自動測量對于精度、可重復(fù)測量精度來說并不是最好的方式渔呵。

As the sharp shadow enters the vision camera sensor (and it is possible to see it on the screen), immediately the software estimates the limit between the black Pixel and the white one and gives the distance compared to a memorized fixed point (for instance: rotation axis).

當(dāng)刀具輪廓進(jìn)入CMOS顯示系統(tǒng)時怒竿，軟件會立即跟蹤到刀具輪廓黑白相間的這部分，并且給出此點的相對值（例如：旋轉(zhuǎn)主軸）扩氢。

In every point you'll find the shadow , the software always estimates the distance. It is a very quick method and of big effect, however it brings some errors in. The errors depend on the lens bending, on the sensor central Pixel distance to the one interested in measure, on the analogical/digital signals processing.

對于任何一個點耕驰，你都能在屏幕上找到陰影，軟件總是能夠計算出這個點的相對距離椎裕。這是一種快速的測量方法言丧，然而它有著很多的缺點和誤差。誤差主要由：透鏡的曲率皿进、以及傳感器對于距離的測量又經(jīng)過一次模擬量到數(shù)字量的轉(zhuǎn)換引起的辕寺。

CCD→Analogical signal→Analogical/digital converter →Digital signal→Electronics

CCD→模擬量信號→模數(shù)轉(zhuǎn)換器→數(shù)字信號→電子信息

C-MOS→Digital signal→Electronics

C-MOS→數(shù)字信號→電子信息

The analogical/digital signal converter brings errors in.

模數(shù)轉(zhuǎn)換器帶來了轉(zhuǎn)換誤差。

In conclusion, in the automatic measuring method a 3÷6μm repeatability is normal. Always when the exact focus choice is precise and steady.

我們的結(jié)論是臊瞬，在自動測量模式下误扯，3-6μm的可重復(fù)測量精度是正常的。（當(dāng)我們選擇的聚焦點是準(zhǔn)確的）

Collimation on fixed reticle

Just to avoid autocollimation  errors, only Elbo Controlli gives a second working method. In this case the Pixel that calculate, the measure will be always the same and will have a central position.

為了避免測量誤差银景，全球?qū)Φ秲x制造商只有ELBO Controlli提出了另外一種新的工作方法骇瓦。總是把圖象顯示在屏幕中心位置诽粪，從而我們得到的測量結(jié)果有著很好的穩(wěn)定性庶咨。

So no lens bending error. The sensor Pixel is always the same and it is in the centre.

如果不存在透鏡的曲率誤差，那么圖象總是顯示的屏幕中心的同一個位置君铁。

Furthermore the C-MOS sensor doesn’t need a converter.

另外民轴，C-MOS傳感器不需要一個模-數(shù)轉(zhuǎn)換器。

In order to have the best repeatability /reproducibility and also accuracy you need to pay the utmost attention to the focus bar. X axis has often a different focus from Z axis one (tools rake).

為了獲得最好的可重復(fù)性測量精度以及精度標(biāo)準(zhǔn)球订，必須引起對聚焦條足夠的重視后裸。X軸和Z 軸分別有一個聚焦條顯示。

You always have to check the repeatability one axis every time and focus with the bar only one axis at a time.

必須檢測可重復(fù)測量的精度冒滩，每次都必須使圖象聚焦度最大微驶。

Every focus bar segment is 2÷3μm.

聚焦條一個小格為2/3μm。

If the bar doesn’ t remain steady but swings, lighting and switching only one segment off, you can have 1÷3μm of difference.

如果聚焦條不穩(wěn)定开睡，一直在閃爍因苹，光學(xué)和電源配置系統(tǒng)只能引起一個聚焦條小格的偏移，這樣就有1-3μm的偏差篇恒。

The kind of environment light , the shadows we simply have when the operator moves, the sharp metals reflection can cause light changes and therefore the focus bar instability.

外界環(huán)境下的光源系統(tǒng)扶檐，不可避免出現(xiàn)光源的一個影子凶杖，當(dāng)操作者移動時，金屬的反射會引起光的變化款筑，因此聚焦條會閃爍智蝠。

Then you have to check also the X and Z axes digital comparators.

然后你必須檢查X軸和Z 軸的數(shù)字比較器。

 In the repeatability tests the zero reference is basic. Only a little swing of the red indicator is enough to determinate differences of 1÷3μm. You have to do the measurings only when both the digital comparator and the axis in measure focus bar are perfectly steady  and exactly in the same points.

零點的測量對于可重復(fù)性測量是最基本的浩出。僅僅一點點兒的震動铭梯，紅色指示器足夠確定出1/3μm。你不得不做測量扶蜻，當(dāng)數(shù)字比較器和軸的聚焦條在同一點是確定的巷同、穩(wěn)定的。

You have also to pay the utmost attention not to create a counting inversion error, measuring always in the same direction.

測量時必須引起足夠的重視：為了避免一個倒置方向性的錯誤搔绿，軸的移動必須始終向著同一個方向豁箱。

 If you measure form right to left , please remember that if you get over the digital comparator zero, you have to go back and repeat. If you get over the zero, you have never to go back on the zero from left to right

( about the counting inversion error there are many treatises, it is not a problem that concerns Elbo Controlli itself  but all the measuring systems).

如果你的測量方向是從右至左的，那么你得注意你是否把光標(biāo)移動過了零點法顺。如果過了零點归闺，那么你不得不返回重新移動測量。（關(guān)于這個倒置后產(chǎn)生誤差有很多的論述瓤鬓，這不是ELBO本身的問題版幕，而且是整個測量界面臨的問題）乏束。

The correct procedure explained in the training to do repeatability and reproducibility tests is the following:

正確的程序是我們在做可重復(fù)性測量測試時：

-          set(position-plan) the measuring function out on the fixed reticle.

-          對于“十”字刻線設(shè)置正確的測量函數(shù)四乱。

-          move  the axes till the sharp shadow enters the screen and bring it near the axis measure reference (for instance the digital comparator lights up).

-          移動軸直到其輪廓進(jìn)入屏幕，逼近軸糖埋，直至出現(xiàn)數(shù)字比較器宣吱。

-          Turn the sharp till the focus bar lights all up.

-          移動，直至尖端的逼近出現(xiàn)聚焦條瞳别。

-          In this position do sharp microrotations clockwise and counterclockwise. The focus bar has always to remain at most, while the digital comparator red reference does very small swings.

-          在這個位置對主軸做一下順時針和逆時針移動征候。聚焦條總是存在，當(dāng)數(shù)字比較器的顯示紅色祟敛，存在一些小的震動時疤坝。

-          With the focus bar at most, go on the most left point of the digital comparator and now stop the spindle rotation; the focus bar has to be completely lightened and has not to switch on or off segments.

-          當(dāng)聚焦條出現(xiàn)了絕大部分時，繼續(xù)向左移動數(shù)字比較器顯示值停止馆铁，停止主軸的旋轉(zhuǎn)跑揉；聚焦條完全的點亮并顯示在屏幕，并且中間沒有分割點埠巨。

-          Move with the X axis micrometric movement the sharp shadow, till the digital comparator red light is on the zero right position.

-          微調(diào)移動X軸接近“十”字比較尺历谍，直到數(shù)字比較器的指示燈在零點右邊變亮。

-          Always with the X axis micrometric adjusting, bring the indicator on the digital comparator to zero.

-          微調(diào)X軸辣垒，使數(shù)字比較器逐漸到零點望侈。

-          If you get over the zero, repeat the reading, going back to the right position with the indicator.

-          如果移動過程中越過了零點位置印蔬，必須返回“十”字刻線右邊。

-          With the bar at most and the red indicator on zero, in total absence of movements: read the quote.

-          聚焦條大多在紅色指示器在零點時猛疗，停止移動軸铅州，讀出數(shù)值。

-          Repeat and see the differences.

-          重復(fù)測量找出每次測量的不同盲狈。

In the workshop 1÷2μm are usual, with great attention and a little practise and experience.

在車間環(huán)境下旱已，1÷2μm的測量誤差是正常的，測量時操作人員必須有足夠的耐心螺矮。

For what said in the introduction the zero value is improbable.

實際上殿漆，零點也不是完全真實存在的。

During the training, this practical test is made many times on all the machines and 2/3μm values are always considered very good在實際測量中畅型，經(jīng)過多次測量肾蕉，所有的機器得到2÷3μm的誤差值是非常棒的結(jié)果！

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