外文翻譯---復(fù)雜光學(xué)曲面慢刀伺服超精密車(chē)削技術(shù)研究

1、<p>　　Study on the Technology of Slow Tool Servo Ultra-Precision Diamond Turning for Complex Optical Surface</p><p>　　Journal of Manufacturing Systems Vol. 16/No. 1 1997</p><p>　　The inclu

2、sion of freeform elements in an optical system provides opportunities for numerous improvements in performance. However, designers are reluctant to utilize freeform surfaces due to the complexity and uncertainty of their

3、 fabrication. Single diamond turning is a novel machining process capable of generating freeform optical surfaces or rotational non-symmetric surfaces at high levels of accuracy. In order to achieve good results with thi

4、s technology some key parameters need to be satisfi</p><p>　　Slow Tool Servo and Fast Tool Servo are the develop faster ultra-precision processing technology in the rencent , the two kind of technology can s

5、ignificantly improve the microstructure are arrays and free surface optical device processing efficiency.</p><p>　　Slow Tool Servo is on the lathe spindle and turning the Z axis are control, make the spindle

6、 into position controllable C axis, machine Tool of the X and Z, C three axis in the space form the cylindrical coordinate system, at the same time, high performance and high programming of CNC system will resolution com

7、plex face form components of the three-dimensional cartesian coordinate into polar coordinates, and all moving axis to send interpolation into to instructions, precise coordination shaft a</p><p>　　Fast Tool

8、 Servo turning and slow knife Servo differ in that will be processing complex shape face turning into shape face and form the microstructure of the surface, and then will both stack. The X axis and Z axis to realize the

9、turn into shape trajectory, lathe spindle of only position detection do not track control. With installed in the Z axis but independent of CNC outside the system of redundancy axes to drive the cutting tools, complete tu

10、rning the surface microstructure form the Z axis mo</p><p>　　Diamond tools in piezoelectric actuators can be under the reciprocating movement of the Z axis. Control system in real-time acquisition spindle An

11、gle signal, and on the basis of real-time sends out of control, real-time control tool to micro into, so as to realize the cutting tool tracking face form the rise and fall of the change. A sharp sword servo in processin

12、g only for parts before face form for accurate calculation, generation of the components of the form that can characterize data files.</p><p>　　Freeform surfaces can be used in optical systems to achieve nov

13、el functions, improve performances, reduce size, and decrease the cost of various products. Therefore, optical freeform surfaces find applications in the fields of optics, medicine, fiber communication, life science, aer

14、ospace etc. Freeform optics has become the key element of quantitative light technology, which is becoming increasingly important in various fields. However, designers are reluctant to utilize freeform surfaces due to<

15、;/p><p>　　1. The theory of Slow Tool Servo turning and key technologies. A systematic introduction of the theory of Slow Tool Servo turning is first given by analyzing machine architecture and movements. By com

16、paring with some other conventional technologies, the key technologies are high dynamic feed drive system, advanced interpolation technology and position control spindle technology. Then, the research emphasis on the per

17、formance of feed drive system and curve interpolation algorithm. Several aspects</p><p>　　2. The design theory of tool geometry parameters in ultra-precision Slow Tool Servo turning complex optical surface.

18、Based on the requirements of slow tool servo, two types of tool are designed and analytic geometry models of cutting edge are built. A geometrical approach is introduced to formulate the relationship between tool tip and

19、 complex surface. By virtue of surface analytic method, the problem is solved efficiently, combined with the NURBS representation of complex surface. Experiments a</p><p>　　3. The programming theory of tool

20、path in ultra-precision Slow Tool Servo turning complex optical surface. In the basic design algorithm of complex optical surface slow tool servo turning, firstly study on the tool contact path design method and accuracy

21、 control skills of discrete process. Then, cutting edge compensation problem is considered. Two algorithms (normal direction compensation method and keeping X steady method) are proposed to avoid interfaces between surfa

22、ce and tool tip of zero ra</p><p>　　4. The error model and simulation algorithm of Slow Tool Servo turning. Base on the discrete vector intersection, geometry simulation algorithm of slow tool servo turning

23、is constructed. Then, major error sources and its transformations in complex surface turning are analyzed. An error model of slow tool servo turning is built base on multi-body theory. Experiments are carried out to vali

24、date simulation algorithm and error model.</p><p>　　5. Finally, plentiful experiments are performed on a variety of complex optical surfaces including off-axis parabolic, array lenses, wave front correcting

25、glass, spiral phase plate, continuous phase plate and so on. The successful machining results prove the validity and advantages of the proposed algorithms and the proposed process improvements.</p><p>　　Slow

26、 knife servo turning the typical machine tool layout forms as shown in figure 1 shows, and common single point diamond turning and a sharp sword servo turning processing layout is similar. Two straight line into a "

27、T" to shaft font layout. The main shaft is installed on the X axis. X axis direction of the movement and workpiece axis of vertical direction of the axis. Cutting tools installed in the Z axis, movement direction pe

28、rpendicular to the X axis and the spindle and workpiece axis paral</p><p>　　Fig.1 Configuration of slow-tool-servo turning lathe</p><p>　　This in ultra-precision turning ordinary machine develop

29、ed on the basis, the spindle movement speed control to the position control, use C, X, Z axis in polar coordinates or cylindrical coordinate system linkage realized in the rotary symmetrical surface processing method, be

30、cause the Z axis motion drive tools can only achieve the highest dozens of Hertz, compared with a sharp sword hundreds, even thousands of Hertz sports slower so called slow knife servo technology.</p><p>　　復(fù)

31、雜光學(xué)曲面慢刀伺服超精密車(chē)削技術(shù)研究</p><p>　　自由曲面光學(xué)元件具有許多優(yōu)異的光學(xué)性能，越來(lái)越多地應(yīng)用到現(xiàn)代光學(xué)系統(tǒng)設(shè)計(jì)中。而自由曲面光學(xué)元件制造的復(fù)雜性和不確定性是制約其應(yīng)用的瓶頸之一。慢刀伺服單點(diǎn)金剛石車(chē)削是一種可以加工很高精度自由曲面光學(xué)表面或非回轉(zhuǎn)對(duì)稱(chēng)光學(xué)曲面的新技術(shù)。機(jī)床伺服執(zhí)行能力是自由曲面能否加工的基本條件。金剛石刀具幾何參數(shù)的選擇、刀具路徑規(guī)劃及刀具半徑補(bǔ)償是確保加工精度的關(guān)鍵。在理論上

32、，對(duì)伺服執(zhí)行能力進(jìn)行了分析；發(fā)展了基于曲面特性分析的刀具參數(shù)確定方法；研究了穩(wěn)定 X 軸的刀具圓弧半徑補(bǔ)償及刀具路徑生成技術(shù)。使用慢刀伺服技術(shù)加工了多種典型的自由曲面光學(xué)元件，取得了較好的結(jié)果。</p><p>　　慢刀伺服和快刀伺服車(chē)削是2種近年發(fā)展比較快的超精密加工技術(shù)，這2種技術(shù)均能顯著提高微結(jié)構(gòu)陣列和自由曲面光學(xué)器件的加工效率。</p><p>　　慢刀伺服車(chē)削是對(duì)車(chē)床主軸與Z軸均

33、進(jìn)行控制，使機(jī)床主軸變成位置可控的C軸，機(jī)床的X、Z、C三軸在空間構(gòu)成了柱坐標(biāo)系，同時(shí)，高性能和高編程分辨率的數(shù)控系統(tǒng)將復(fù)雜面形零件的三維笛卡爾坐標(biāo)轉(zhuǎn)化為極坐標(biāo)，并對(duì)所有運(yùn)動(dòng)軸發(fā)送插補(bǔ)進(jìn)給指令，精確協(xié)調(diào)主軸和刀具的相對(duì)運(yùn)動(dòng)，實(shí)現(xiàn)對(duì)復(fù)雜面形零件的車(chē)削加工。慢刀伺服車(chē)削Z軸和X軸往往同時(shí)作正弦往復(fù)運(yùn)動(dòng)，需要多軸插補(bǔ)聯(lián)動(dòng)。因此，在加工前需要對(duì)零件面形進(jìn)行多軸協(xié)調(diào)分析，進(jìn)而確定刀具路徑和刀具補(bǔ)償。此外，慢刀伺服受機(jī)床滑座慣性和及電動(dòng)機(jī)響應(yīng)速度影

34、響較大，機(jī)床動(dòng)態(tài)響應(yīng)速度較低，適合加工面形連續(xù)而且較大的復(fù)雜光學(xué)器件。</p><p>　　快刀伺服車(chē)削與慢刀伺服的差別在于：將被加工的復(fù)雜形面分解為回轉(zhuǎn)形面和形面上的微結(jié)構(gòu)，然后將兩者疊加。由X軸和Z軸進(jìn)給實(shí)現(xiàn)回轉(zhuǎn)形面的軌跡運(yùn)動(dòng)，對(duì)車(chē)床主軸只進(jìn)行位置檢測(cè)并不進(jìn)行軌跡控制。借助安裝在Z軸但獨(dú)立于車(chē)床數(shù)控系統(tǒng)之外的冗余運(yùn)動(dòng)軸來(lái)驅(qū)動(dòng)刀具，完成車(chē)削微結(jié)構(gòu)形面所需的Z軸運(yùn)動(dòng)。這種加工方法具有高頻響、高剛度、高定位精度的特

35、點(diǎn)。</p><p>　　金剛石刀具在壓電陶瓷驅(qū)動(dòng)下可以進(jìn)行Z軸的往復(fù)運(yùn)動(dòng)。控制系統(tǒng)在實(shí)時(shí)采集主軸角度信號(hào)的基礎(chǔ)上，實(shí)時(shí)發(fā)出控制量，控制刀具實(shí)時(shí)微進(jìn)給，從而實(shí)現(xiàn)刀具跟蹤工件面形的起伏變化。快刀伺服在加工前僅需對(duì)零件面形進(jìn)行精確計(jì)算，生成能表征零件面形的數(shù)據(jù)文件。此外，快刀伺服系統(tǒng)的運(yùn)動(dòng)頻響高、行程只有數(shù)毫米，更適于加工面形突變或不連續(xù)、有限行程內(nèi)的微小結(jié)構(gòu)。</p><p>　　復(fù)雜光學(xué)曲

36、面在提高光學(xué)系統(tǒng)性能。實(shí)現(xiàn)特殊光學(xué)特性。減少系統(tǒng)零件數(shù)量。減小系統(tǒng)尺寸等方面有許多顯而易見(jiàn)的優(yōu)點(diǎn)。隨著光電信息技術(shù)的迅猛發(fā)展。復(fù)雜光學(xué)曲面零件的應(yīng)用領(lǐng)域?qū)⑹謴V闊。復(fù)雜光學(xué)曲面無(wú)疑是非球面光學(xué)零件發(fā)展和應(yīng)用的趨勢(shì)之一。但目前還遠(yuǎn)未能納入到現(xiàn)代光學(xué)系統(tǒng)的主流當(dāng)中。問(wèn)題的重要原因之一就在于復(fù)雜光學(xué)曲面的超精密制造相當(dāng)困難。隨著機(jī)床技術(shù)的進(jìn)步。直線電機(jī)驅(qū)動(dòng)、主軸伺服等一系列新技術(shù)應(yīng)用于超精密車(chē)床的設(shè)計(jì)中。使得一種新的基于慢刀伺服技術(shù)的超精密車(chē)

37、削創(chuàng)成加工成為可能。機(jī)床具有主軸伺服的多軸聯(lián)動(dòng)功能。刀具可嚴(yán)格按照規(guī)劃路徑相對(duì)于工件復(fù)雜表面運(yùn)動(dòng)。實(shí)現(xiàn)各種高精度的復(fù)雜曲面加工。本文以慢刀伺服車(chē)削技術(shù)作為復(fù)雜光學(xué)曲面的加工手段。對(duì)其創(chuàng)成原理、刀具設(shè)計(jì)、軌跡規(guī)劃和精度分析等幾方面的關(guān)鍵技術(shù)開(kāi)展研究。</p><p>　　慢刀伺服超精密車(chē)削技術(shù)原理及關(guān)鍵技術(shù)通過(guò)對(duì)機(jī)床結(jié)構(gòu)和創(chuàng)成運(yùn)動(dòng)的分析。研究了慢刀伺服車(chē)削加工原理。揭示了其與快刀伺服和普通三軸數(shù)控加工之間的根本區(qū)別

38、。分析指出：直線軸運(yùn)動(dòng)性能、先進(jìn)插補(bǔ)技術(shù)以及主軸位置控制是技術(shù)關(guān)鍵所在。為研究制約進(jìn)給驅(qū)動(dòng)性能的關(guān)鍵因素。建立了直線驅(qū)動(dòng)進(jìn)給系統(tǒng)模型。開(kāi)展了一系列仿真及實(shí)驗(yàn)研究。研究表明進(jìn)給軸達(dá)到高動(dòng)態(tài)、高精度驅(qū)動(dòng)的必要條件是：導(dǎo)軌具有足夠的動(dòng)態(tài)剛度。反饋環(huán)節(jié)量化誤差噪聲抑制到較低水平。針對(duì)復(fù)雜曲面數(shù)控插補(bǔ)問(wèn)題。提出了適應(yīng)加工特點(diǎn)的參數(shù)計(jì)算方法。將PvT插補(bǔ)技術(shù)引入復(fù)雜曲面車(chē)削。解決了使用線性插補(bǔ)存在的弊端。從伺服軸驅(qū)動(dòng)能力限制和軌跡跟蹤精度兩個(gè)角度分

39、析。得到伺服軸執(zhí)行能力幅頻圖。用于確定可加工范圍。這些研究為構(gòu)建慢刀伺服加工平臺(tái)。正確選擇慢刀伺服加工方法奠定了理論基礎(chǔ)。</p><p>　　復(fù)雜光學(xué)曲面慢刀伺服超精密車(chē)削的刀具設(shè)計(jì)理論刀具設(shè)計(jì)是指刀具模型的建立和幾何參數(shù)的確定。運(yùn)用解析分析方法。得到了切削刃輪廓的空間解析模型。為確定刀具幾何參數(shù)的合理范圍。從復(fù)雜曲面面形、加工表面微觀形貌、加工表面光學(xué)特性以及加工材料等角度。研究了對(duì)刀具幾何參數(shù)的制約關(guān)系。復(fù)

40、雜曲面每一點(diǎn)處對(duì)刀具的限制均不相同。通過(guò)對(duì)曲面基本方程的分析。推導(dǎo)出代表制約關(guān)系的關(guān)鍵矢量。解決了復(fù)雜曲面對(duì)刀具制約問(wèn)題。這些工作為復(fù)雜曲面慢刀伺服車(chē)削加工合理設(shè)計(jì)刀具提供了理論支撐。</p><p>　　復(fù)雜光學(xué)曲面慢刀伺服超精密車(chē)削的刀具路徑規(guī)劃理論精確規(guī)劃刀具路徑是復(fù)雜曲面車(chē)削加工的基本要求。在合理規(guī)劃刀具接觸點(diǎn)軌跡的基礎(chǔ)上。采用誤差控制的方法離散。提出法向偏置和穩(wěn)定x軸偏置兩種方法補(bǔ)償?shù)毒咔邢魅休喞＝Y(jié)合

41、提出的刀位點(diǎn)修正方法解決前角非零刀具過(guò)切與欠切問(wèn)題?？筛咝Ь_獲得合理刀具路徑。針對(duì)刀具路徑在曲面邊界外的情況。創(chuàng)造性地利用空間曲線插值技術(shù)在螺旋曲線上延拓刀位軌跡。實(shí)現(xiàn)了刀具路徑的平滑過(guò)渡。為達(dá)到提高復(fù)雜光學(xué)曲面車(chē)削精度的目的。提出了基于刀位點(diǎn)修正的慢刀伺服車(chē)削誤差補(bǔ)償算法。利用數(shù)據(jù)濾波方法或Zemike重構(gòu)方法。從加工誤差中分離出需要補(bǔ)償?shù)恼`差分量。對(duì)刀具路徑進(jìn)行修正后再次加工?？蓪?shí)現(xiàn)特定面形誤差成分的補(bǔ)償。這些研究為生成高質(zhì)量的數(shù)

42、控程序。拓展加工范圍。提高加工精度提供了理論指導(dǎo)。</p><p>　　慢刀伺服超精密車(chē)削的精度建模與仿真分析加工過(guò)程定量分析包含幾何仿真和誤差分析兩個(gè)相互聯(lián)系的重要方面。用z-map矢量表達(dá)曲面。以刀位點(diǎn)間隔作為仿真步長(zhǎng)。通過(guò)坐標(biāo)變換和擬合算法獲得刀刃輪廓掃描曲面。討論了矢量與NuRBS曲面交點(diǎn)的求解方法。對(duì)z-map矢量進(jìn)行更新。解決了慢刀伺服車(chē)削的幾何仿真問(wèn)題。針對(duì)各種誤差源的影響。詳細(xì)研究了誤差特征矩陣。

43、以多體系統(tǒng)理論推導(dǎo)了包含誤差因素的成形函數(shù)。解決了仿真分析誤差影響的問(wèn)題。精度仿真、預(yù)測(cè)、分析系統(tǒng)的建立為深入認(rèn)識(shí)慢刀伺服車(chē)削機(jī)理。開(kāi)展精度分析。預(yù)測(cè)加工結(jié)果等提供了有力手段。</p><p>　　復(fù)雜光學(xué)曲面慢刀伺服超精密車(chē)削實(shí)驗(yàn)復(fù)雜光學(xué)曲面加工實(shí)驗(yàn)用于所述理論的全面驗(yàn)證。離軸拋物面鏡的加工主要體現(xiàn)了以仿真分析為指導(dǎo)。解決刀具對(duì)中誤差對(duì)面形精度的影響；在凹球面反射鏡陣列加工中。主要體現(xiàn)了刀具路徑規(guī)劃方式對(duì)伺服軸

44、動(dòng)態(tài)性能的不同要求；在波前校正眼鏡加工中。主要驗(yàn)證了加工、檢測(cè)、修正、再加工循環(huán)對(duì)提高面形精度的作用；螺旋相位板、連續(xù)相位板的加工主要體現(xiàn)了慢刀伺服技術(shù)在解決傳統(tǒng)工藝難題方面的優(yōu)勢(shì)。從上述幾方面入手。探討了如何利用慢刀伺服超精密車(chē)削技術(shù)實(shí)現(xiàn)復(fù)雜光學(xué)曲面高精度加工。研究成果對(duì)慢刀伺服車(chē)削加工機(jī)床的建立具有指導(dǎo)作用。對(duì)復(fù)雜曲面慢刀伺服車(chē)削加工具有技術(shù)支撐作用</p><p>　　慢刀伺服車(chē)削典型的機(jī)床布局形式如圖 1

45、 所示，與普通單點(diǎn)金剛石車(chē)削以及快刀伺服車(chē)削加工布局類(lèi)似。兩根直線進(jìn)給軸呈“T”字形布局。工件主軸安裝在 X 軸上。X 軸的移動(dòng)方向與工件主軸的旋轉(zhuǎn)軸方向垂直。刀具安裝在 Z 軸，運(yùn)動(dòng)方向垂直于 X 軸并與工件主軸旋轉(zhuǎn)軸線平行。工件安裝在主軸上并且隨之一起轉(zhuǎn)動(dòng)，金剛石刀具按照工件不同的角度?? 和徑向位置 x 相對(duì)于工件表面運(yùn)動(dòng)，即刀具運(yùn)動(dòng)應(yīng)由圓柱坐標(biāo)系。</p><p>　　Fig.1 Configuratio