外文翻譯---復雜光學曲面慢刀伺服超精密車削技術研究

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

31、雜光學曲面慢刀伺服超精密車削技術研究</p><p>　　自由曲面光學元件具有許多優(yōu)異的光學性能，越來越多地應用到現代光學系統設計中。而自由曲面光學元件制造的復雜性和不確定性是制約其應用的瓶頸之一。慢刀伺服單點金剛石車削是一種可以加工很高精度自由曲面光學表面或非回轉對稱光學曲面的新技術。機床伺服執(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的選擇、刀具路徑規(guī)劃及刀具半徑補償是確保加工精度的關鍵。在理論上

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

33、進行控制，使機床主軸變成位置可控的C軸，機床的X、Z、C三軸在空間構成了柱坐標系，同時，高性能和高編程分辨率的數控系統將復雜面形零件的三維笛卡爾坐標轉化為極坐標，并對所有運動軸發(fā)送插補進給指令，精確協調主軸和刀具的相對運動，實現對復雜面形零件的車削加工。慢刀伺服車削Z軸和X軸往往同時作正弦往復運動，需要多軸插補聯動。因此，在加工前需要對零件面形進行多軸協調分析，進而確定刀具路徑和刀具補償。此外，慢刀伺服受機床滑座慣性和及電動機響應速度影

34、響較大，機床動態(tài)響應速度較低，適合加工面形連續(xù)而且較大的復雜光學器件。</p><p>　　快刀伺服車削與慢刀伺服的差別在于：將被加工的復雜形面分解為回轉形面和形面上的微結構，然后將兩者疊加。由X軸和Z軸進給實現回轉形面的軌跡運動，對車床主軸只進行位置檢測并不進行軌跡控制。借助安裝在Z軸但獨立于車床數控系統之外的冗余運動軸來驅動刀具，完成車削微結構形面所需的Z軸運動。這種加工方法具有高頻響、高剛度、高定位精度的特

35、點。</p><p>　　金剛石刀具在壓電陶瓷驅動下可以進行Z軸的往復運動?？刂葡到y在實時采集主軸角度信號的基礎上，實時發(fā)出控制量，控制刀具實時微進給，從而實現刀具跟蹤工件面形的起伏變化?？斓端欧诩庸で皟H需對零件面形進行精確計算，生成能表征零件面形的數據文件。此外，快刀伺服系統的運動頻響高、行程只有數毫米，更適于加工面形突變或不連續(xù)、有限行程內的微小結構。</p><p>　　復雜光學曲

36、面在提高光學系統性能。實現特殊光學特性。減少系統零件數量。減小系統尺寸等方面有許多顯而易見的優(yōu)點。隨著光電信息技術的迅猛發(fā)展。復雜光學曲面零件的應用領域將十分廣闊。復雜光學曲面無疑是非球面光學零件發(fā)展和應用的趨勢之一。但目前還遠未能納入到現代光學系統的主流當中。問題的重要原因之一就在于復雜光學曲面的超精密制造相當困難。隨著機床技術的進步。直線電機驅動、主軸伺服等一系列新技術應用于超精密車床的設計中。使得一種新的基于慢刀伺服技術的超精密車

37、削創(chuàng)成加工成為可能。機床具有主軸伺服的多軸聯動功能。刀具可嚴格按照規(guī)劃路徑相對于工件復雜表面運動。實現各種高精度的復雜曲面加工。本文以慢刀伺服車削技術作為復雜光學曲面的加工手段。對其創(chuàng)成原理、刀具設計、軌跡規(guī)劃和精度分析等幾方面的關鍵技術開展研究。</p><p>　　慢刀伺服超精密車削技術原理及關鍵技術通過對機床結構和創(chuàng)成運動的分析。研究了慢刀伺服車削加工原理。揭示了其與快刀伺服和普通三軸數控加工之間的根本區(qū)別

38、。分析指出：直線軸運動性能、先進插補技術以及主軸位置控制是技術關鍵所在。為研究制約進給驅動性能的關鍵因素。建立了直線驅動進給系統模型。開展了一系列仿真及實驗研究。研究表明進給軸達到高動態(tài)、高精度驅動的必要條件是：導軌具有足夠的動態(tài)剛度。反饋環(huán)節(jié)量化誤差噪聲抑制到較低水平。針對復雜曲面數控插補問題。提出了適應加工特點的參數計算方法。將PvT插補技術引入復雜曲面車削。解決了使用線性插補存在的弊端。從伺服軸驅動能力限制和軌跡跟蹤精度兩個角度分

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

40、雜曲面每一點處對刀具的限制均不相同。通過對曲面基本方程的分析。推導出代表制約關系的關鍵矢量。解決了復雜曲面對刀具制約問題。這些工作為復雜曲面慢刀伺服車削加工合理設計刀具提供了理論支撐。</p><p>　　復雜光學曲面慢刀伺服超精密車削的刀具路徑規(guī)劃理論精確規(guī)劃刀具路徑是復雜曲面車削加工的基本要求。在合理規(guī)劃刀具接觸點軌跡的基礎上。采用誤差控制的方法離散。提出法向偏置和穩(wěn)定x軸偏置兩種方法補償刀具切削刃輪廓。結合

41、提出的刀位點修正方法解決前角非零刀具過切與欠切問題?？筛咝Ь_獲得合理刀具路徑。針對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在螺旋曲線上延拓刀位軌跡。實現了刀具路徑的平滑過渡。為達到提高復雜光學曲面車削精度的目的。提出了基于刀位點修正的慢刀伺服車削誤差補償算法。利用數據濾波方法或Zemike重構方法。從加工誤差中分離出需要補償的誤差分量。對刀具路徑進行修正后再次加工?？蓪崿F特定面形誤差成分的補償。這些研究為生成高質量的數

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

43、以多體系統理論推導了包含誤差因素的成形函數。解決了仿真分析誤差影響的問題。精度仿真、預測、分析系統的建立為深入認識慢刀伺服車削機理。開展精度分析。預測加工結果等提供了有力手段。</p><p>　　復雜光學曲面慢刀伺服超精密車削實驗復雜光學曲面加工實驗用于所述理論的全面驗證。離軸拋物面鏡的加工主要體現了以仿真分析為指導。解決刀具對中誤差對面形精度的影響；在凹球面反射鏡陣列加工中。主要體現了刀具路徑規(guī)劃方式對伺服軸

44、動態(tài)性能的不同要求；在波前校正眼鏡加工中。主要驗證了加工、檢測、修正、再加工循環(huán)對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了慢刀伺服技術在解決傳統工藝難題方面的優(yōu)勢。從上述幾方面入手。探討了如何利用慢刀伺服超精密車削技術實現復雜光學曲面高精度加工。研究成果對慢刀伺服車削加工機床的建立具有指導作用。對復雜曲面慢刀伺服車削加工具有技術支撐作用</p><p>　　慢刀伺服車削典型的機床布局形式如圖 1

45、 所示，與普通單點金剛石車削以及快刀伺服車削加工布局類似。兩根直線進給軸呈“T”字形布局。工件主軸安裝在 X 軸上。X 軸的移動方向與工件主軸的旋轉軸方向垂直。刀具安裝在 Z 軸，運動方向垂直于 X 軸并與工件主軸旋轉軸線平行。工件安裝在主軸上并且隨之一起轉動，金剛石刀具按照工件不同的角度?? 和徑向位置 x 相對于工件表面運動，即刀具運動應由圓柱坐標系。</p><p>　　Fig.1 Configuratio