外文翻譯--基于摩擦傳動的高分辨率和大沖程的微量進給機械系統(tǒng)

附錄： 外文資料與中文翻譯 Micro-feed Mechanism with High-Resolution and Large-Stroke Based on Friction Drive Haitao Liu, Zesheng Lu School of Mechantronics Engineering, Harbin Institute of Technology ABSTRACT Based on friction driving principle, design a long stroke length and high resolution walking micro-feeding device driven by piezoelectric ceramic elements and combined with the screw shaft and aerostatic guide way. The design was made to the adjustable preload device by flexible four-bar linkage. The static properties of flexible linkage device are analyzed with FEM. The transmission characteristics of micro-feeding device are exhaustively analyzed. Keywords: Friction drive, Piezoelectric actuator, Flexure hinge,Finite element 1. INTRODUCTION Aspheric optics has been widely used in industries such as aviation, aerospace, national defense and so on. However, the manufacture of large aspheric optics faces many problems such as great difficulty, low efficiency, high cost, increased requirement on process equipment etc 1, 2 . In order to arrive at high precision, the micro displacement resolution of ultra-precision machine must be further advanced, so as to compensating the processing error online. Therefore, the design of micro-feed mechanism has become one of the key technologies 3-7 . PZT is the new micro-feed mechanism developed in recent years. It has the advantages such as small volume, large power, high resolution, and high frequency response and so on and phenomena such as no heating, no backlash and mucosity, so its widely used micro controller in micro-feed mechanism. Nowadays, friction gearing mechanism is gradually been acquired and used 8, 9. 2. STRUCTURE AND OPERATING PRINCIPLE OF MICRO-FEED MECHANISM The micro-feed mechanism is made up of three parts: friction gearing, ball screw and static-pressure air-bearing guide way. Micro-feed mechanism uses the piezoelectricity ceramic friction gearing block, which twist up the sleeve and drive the ball screw, so as to bring along the air-bearing guide way to realize the micro-feed movement. The structure is shown as Figure 1. 1-Bearing bracket 2-Friction gearing block 3 Friction gearing sleeve 4-Static-pressure air-bearing guide way 5- Ball screw 6- Piezoelectricity ceramic base 7-Piezoelectricity ceramic used for feeding Figure 1: (a) Structure of the feed mechanism As shown in Figure 2, the operating principle of the feed mechanis m is that, friction gearing sleeve connects with ball screw, four friction gearing blocks are placed symmetrically at both sides of the sleeve. Each block is droved by the corresponding piezoelectricity ceramic used for feeding and is gripped by the corresponding gripping mechanis m, which is droved by the piezoelectricity ceramic used for gripping to produce clamp force. When feeding mechanism works, the piezoelectricity ceramic used for gripping on the same side drive both the friction gearing blocks to work in certain orderliness, so as that the friction gearing sleeve turn continuously. Figure 1: (b) Picture of the feed mechanism Figure 2: Operating principle of the feeding mechanism 3. DESIGN OF THE ADJUSTABLE PRETIGHTENING MECHANISM An adjustable retightening mechanis m is required in the friction gearing mechanis m, which must has enough pretightening force. The typical pretightening methods are plate spring pretightening mechanis m, helical pretightening mechanism, and air pressure pretightening mechanism and so on. The retightening mechanism designed in this paper is flexible parallel four bars mechanism. Its droved by piezoelectricity ceramic to supply pretightening force. The pretightening force can be changed by controlling the input voltage of piezoelectricity ceramic. As shown in Figure 3, use the finite element software to analysis the static characteristic. When the drive force of piezoelectricity ceramic is 500N in maximum, the rigidity of flexible four bars mechanis m, analyzed by finite element software, is K=24. 1 5N/m, and the maximum stress of flexible hinges is =32.7Mpa. If there is no distortion in flexible four bars mechanis m (that is when the friction gearing blocks contact rigidly), the output force of piezoelectricity ceramic will completely translates to pretightening force through the flexible four bars mechanism. 4. DRIVE CHARACTERISTIC ANALYSIS OF THE MECHANISM Studying and mastering the drive characteristic of mechanism redounds to adopting the proper measures to improve the whole performance and provides the design basis for designing the control system. 4.1 Drive torque When system starts, there is a problem on initial inertia moment as a result of the existence of parts quality. To research the drive torque, choose the friction gearing s leeve as subject investigated. According to the theory that the kinetic energy of gearing train is same before and after conversion, the rotary inertia of each part is transformed to friction sleeve. Because of that, we can get the rotary inertia after conversion is (a) Structure of the pretightening mechanism (b) Node motion nephogram (c) Von-mise stress envelope Figure 3: The static characteristic assay plan of pretightening mechanism Where p is pitch of lead screw, m； r is radius of the friction sleeve, m； mS is quality of the ball screw, kg； T is quality of the friction sleeve, kg. Through the above analysis, we get the equivalent rotary inertia of friction sleeve. Now we choose the friction sleeve as subject investigated to discuss the drive torque （ drive force） that is needed when device starts and its influencing factors. The following equation works when device starts: Where J is equivalent rotary inertia, kgm2； is angular acceleration of friction sleeve, rad/s2； r is radius of the friction sleeve, m； M is drive torque, Nm； F is drive force （ breakout friction between friction block and friction sleeve） , N. When system starts, a condign drive deflecting couple should be applied o n the friction sleeve, in order that the sleeve can have certain angular acceleration. The drive deflecting couple is generated by the output force of piezoelectricity ceramic. From equation 2 we can get that the equivalent rotary inertia of system, radius of the friction sleeve and drive force of the piezoelectricity ceramic (breakout friction between friction block and friction sleeve) are the influencing factor of mechanism start, so we should think over the influence of each factor to ensure the normal start of mechanism. Same questions exist when feed mechanism stop moving. 4.2 Driving rigidity The driving rigidity is one of the important driving characteristics of feed mechanism. Now we will analyze the driving rigidity of feed mechanism in detail as following. The rigidity of the feed mechanism is the cascade connection of the each segment rigidity of the feed mechanism, which has the calculated equation as follows: Where K is the total rigidity of the feed mechanism； K F is the touching rigidity of surface in contact between friction block and friction sleeve； K S is the axial rigidity of lead screw； K S is the axial rigidity changed from the torsional rigidity of lead screw； K N is the rigidity of nut； K B is the rigidity of axial bearing； K H is rigidity of nut bracket and bearing block； K D is the axial rigidity of nut link block； Here is the analysis and calculation of part rigidity. 4.2.1 Rigidity of the piezoelectricity ceramic The piezoelectricity ceramic in this paper is the ceramic micro positioner typed WTYD0808055 produced by China Electronics Technology Group Corporation No.26 Research Institute. Its rigidity measured through experiment is 15.1 5N/m, as shown in Figure 4. 4.2.2 Touching rigidity of surface in contact between friction block and friction sleeve Two objects contacting with each other will have certain tangential transition before relative slip in the action of tangential external force, which is called pre-displacement. The proportional relation between force and displacement reflects a rigidity characteristic in fact 10. The corresponding rigidity now is: Where k is const； N is normal pressure； r is the radius of idealized sphere on friction surface. Its clear in the equation that, in special friction gearing system, k is got from experiment, r is const, the only influencing factor of touching rigidity is normal pressure N. Its evident that the larger N is, the larger the touching rigidity K is. Figure 4: Rigidity curve of piezoelectricity ceramic 4.2.3 Axial rigidity changed from the torsional rigidity of lead screw The dimension of driving chain needs to be transformed uniformly when calculating its rigidity. Therefore, the torsional rigidity must be transformed into axial rigidity as the following equation: Where a is the rising angle of lead screw, ()； d is the diameter of lead screw, mm； F is the axial force of lead screw, N； M is the input moment of lead screw, Nmm； q is the friction angle between lead screw and nut, ()； KT is the torsional rigidity of lead screw, Nmm/rad； 0 is the torsional deformation of lead screw, rad； p is the lead of lead screw, mm； G is the shear modulus of elasticity of lead screw material, Mpa； JP is the inertia moment of cross section, mm4, JP=d4/32； L is the maximum distance from loading point to two thrust bearing, mm. The axial rigidity of nut link block can be gained by the finite element analysis. The rigidity of nut bracket and bearing block is very large, which can be dismissed. The rigidity of other parts can be got by looking up table and calculating. In a word, by deducing the equation of drive rigidity of feed mechanism, we have found the influencing factors of driving rigidity caused by each driving segment, which offers the basis for further study on the driving characteristic. 5. EXPERIMENTAL STUDY OF THE FEED MECHANISM 5.1 Foundation of the experiment system As shown in Figure 5, the experiment system is made up of feed mechanism, computer, piezoelectricity ceramic driver and its power supply and the inductance amesdial. Figure 5: Foundation of experiment system This paper uses a control method based on average curve model to set up the open loop control model. Above all, measure the experimental curve of relation between piezoelectricity ceramic control voltage and slide carriage distance. Using the Matlab software to fit the line with cubic algebraic multinomial, and the fitted line and fitted error line are as shown in Figure 6, from which we get the corresponding relational expression of control voltage and distance and therefore control the distance of feed mechanism. a) Fitted line b) Fitted error line Figure 6: Fit with cubic algebraic multinomial Relational expression of control voltage and distance is as shown in equation 7: Where x is the output distance, m； u is the control voltage, V. 5.2 Experimental study of system resolution As shown in Figure 7, piezoelectricity ceramic has certain elongation. At this time, the distance of micro working table is 0.1 5m. Then step elongating gradually on this base and keep 1.5s in each moment. The sampling time is 100ms. The resolution curve can be gained by measuring the practice distance of micro feed mechanism using the inductance amesdial. Figure 7: Distance resolution curve of feed mechanism 6. CONCLUSION A step micro feed mechanism with long march and high resolution was designed in this paper, and the following conclusions were concluded: 1. Designed the pretightening mechanism based on the piezoelectricity ceramic flexible iron hinges and analyzed its static characteristic using the finite element software； 2. Analyzed the starting torque of micro feed mechanism and calculated the equivalent rotary inertia； analyzed the driving rigidity characteristic of micro feed mechanism and found its influencing factors； 3. The march of the micro feed mechanism can reach 300mm, and the resolution is less than 0.05m. REFERENCES 1. Seugng-Bok Choi, Sang-Soo Han. Position Control System Using ER Clutch and Piezoactuator. Pro. of SPIE, 2003, 5056: 424431 2. Suzuki H, Kodera S, Mabkawa S, et al. Study on Precision Grinding of Micro a Spherical Surface. JSPE, 1998, 64(4):61 9623. 1. Arrasmith S. R, Kozhinova I A, Gregg L L et al. 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ICAMT99. 1999. 基于摩擦傳動的高分辨率和大沖程的微量進給機械系統(tǒng) 哈爾濱工業(yè)大學(xué)機電工程學(xué)院劉海濤，盧澤生 摘 要 在摩擦傳動原理的基礎(chǔ)上 ,設(shè)計了一種通過壓電陶瓷 結(jié)合螺桿軸和氣體靜壓引導(dǎo)的方式 驅(qū)動的長沖程和高分辨率的微量進給系統(tǒng)。設(shè)計用來使加載裝置可以靈活的起落。利用有限元方法對柔性連接裝置對它的靜態(tài)特性進行分析。對這種微量進給系統(tǒng)的傳輸特性進行了詳細的分析。 關(guān)鍵詞 ： 摩擦傳動 壓電傳動裝置 柔性鉸鏈 有限元 1.簡介 光學(xué)在航空、航天、國防等領(lǐng)域中已得到廣泛應(yīng)用的行業(yè)。 然而 ,生產(chǎn)的大型光學(xué)鏡面 面臨著巨大的困難 ,效率較低、成本較高、增加在工藝設(shè)備的要求等。為了獲得更高的精度，高微位移 分辨率超 -先進精密機床有待進一步深入 ,以補償加工誤差。因此 ,微量進給機制的設(shè)計已成為其關(guān)鍵技術(shù)之一。 壓電陶瓷是一種近年來發(fā)展起來的 新型的 微量進給機制。 它所擁有的優(yōu)勢 ,比如體積小、功率大、分辨率高和高頻率響應(yīng) ,恒溫 ,不反彈，無粘性。因此它廣泛使用在微量進給機制。如今 ,摩擦傳動機制逐步被 獲得和使用。 2微量進給機制 的結(jié)構(gòu)和工作原理 微量進給機 制是由三個部分組成 :摩擦傳動裝置、滾珠螺桿及靜態(tài)壓力空氣軸承引導(dǎo)的方式。 采用壓電 陶瓷 微量進給機制阻滯 ,這些摩擦傳動扭曲向上套筒和驅(qū)動器 滾珠絲杠 ,從而帶動空氣軸承引導(dǎo)地實現(xiàn)了微量進給運動。 結(jié)構(gòu)如圖 1 所示。 1， 軸承支架， 2.活塞， 3、活塞缸， 4.精壓力空氣軸承導(dǎo)軌， 5.滾珠絲杠 ，6. 壓電陶瓷底座 ， 7.壓電陶瓷底座 圖一：進給機構(gòu)的結(jié)構(gòu) 按照圖 2 所示的 進 給系統(tǒng)工作原理是 ,套筒連接著球摩擦傳動螺桿、四個模塊是放置的兩側(cè)對稱的軸套。每一塊由相應(yīng)的壓電陶瓷用于驅(qū)動 ,這種機制由于是由壓電陶瓷驅(qū)動，適用于夾持產(chǎn)生夾力。進給機制的運作 ,壓電陶瓷適用于夾持在同一陣營的摩擦傳動驅(qū)動都工作在特定塊整齊 ,從而使摩擦傳動套筒連續(xù)的傳動。 圖 1:(b)進 給系統(tǒng)圖片 圖 2:進料機構(gòu)的運行原理 3結(jié)合設(shè)計的可調(diào)機制 擰緊調(diào)節(jié)機制是一個需要在摩擦傳動機構(gòu)，它必須有足夠的 預(yù)緊力。典型的方法是鋼板彈簧預(yù)緊預(yù)緊機制，螺旋預(yù)緊 機制，氣壓預(yù)緊機制等。 該擰緊機制本文設(shè)計的 靈活的平行四桿機構(gòu)。這是由壓電陶瓷 droved 供應(yīng)預(yù)緊力。 該 預(yù)緊力可以改變控制的壓電陶瓷輸入電壓。 如圖 3 所示，利用有限元軟件分析的靜態(tài)特性。當(dāng)驅(qū)動力的 壓電陶瓷是在最大 500N 的，靈活安排四桿機構(gòu)剛度， 有限元分析 軟件，是 K =24.15N/m，以及最大應(yīng)力彈性鉸鏈?zhǔn)?= 32.7Mpa。 如果沒有靈活失真 四桿機構(gòu)（即當(dāng)摩擦傳動板塊跟硬性），輸出力的壓電 陶瓷將完全轉(zhuǎn)化為預(yù)緊通過靈活的四桿機構(gòu)的力量。 4驅(qū)動特性分析的機制 學(xué)習(xí)和掌握輻射源驅(qū)動特性的機制以便采取適當(dāng)?shù)拇胧?，以改善整體性能，并提供了設(shè)計控制系統(tǒng)設(shè)計的基礎(chǔ)。 4.1 驅(qū)動力矩 當(dāng)系統(tǒng)啟動時，有一個初 步的轉(zhuǎn)動慣量作為零件的質(zhì)量存在問題的結(jié)果。為了研究驅(qū)動力矩，選擇摩擦傳動套筒為主體的影響。根據(jù)該理論認為，動力學(xué)傳動裝置的能量是一樣的火車前和轉(zhuǎn)換后，各部分的轉(zhuǎn)動慣量，轉(zhuǎn)化為摩擦套。正因為如此，我們可以得到轉(zhuǎn)換后的轉(zhuǎn)動慣量。 圖三 :計劃的靜態(tài)特性分析 結(jié)合的機制 P:導(dǎo)程， m R：套筒半徑， m Ms：滾珠螺桿質(zhì)量， kg Mt：套筒質(zhì)量， kg 通過以上分析 ,我們得到的 等效轉(zhuǎn)動慣量的摩擦的袖子?，F(xiàn)在我們選擇摩擦的袖子一樣對象來討論這個驅(qū)動力矩 (動力 ),是需要裝置時開始及其影響因素。下列方程裝置時開始工作： J：等效轉(zhuǎn)動慣量， kg。 m2 R：摩擦套筒半徑， m ：套筒摩擦角加速度， rad/s2 M：驅(qū)動力矩， n。 m F： 驅(qū)動力（摩擦片與套筒之間的摩擦力）， n 當(dāng)系統(tǒng)啟動時，一個適宜的驅(qū)動器偏轉(zhuǎn)組應(yīng)該被應(yīng)用于摩擦套，以使該套可以有一定的角加速度。該驅(qū)動器偏轉(zhuǎn)組所產(chǎn)生的壓電輸出力陶瓷。由式 2 我們可以得到的等效轉(zhuǎn)動慣量的系統(tǒng)，半徑套的摩擦和驅(qū)動器對壓電陶瓷（爆發(fā)摩擦塊之間的摩擦和摩擦套），是影響力機制啟動的因素，所以我們應(yīng)該考慮各因素，以確保機制正常啟動。 4.2 驅(qū)動剛性 剛性的驅(qū)動是其中的重要驅(qū)動進給機構(gòu)的特征之一。 現(xiàn)在我們將分析駕駛進給機構(gòu)的剛度詳細的證明。不靈活的進給機構(gòu)的級聯(lián)連接剛度的飼料的每一個片段的機制 ,這種機制有計 算公式如下 : K：進刀機構(gòu)總體硬度 Ky：壓電陶瓷剛度 Kf： 接觸剛度之間的接觸摩擦表 面的摩擦剛性塊體和壓電陶瓷套筒 Ks： 導(dǎo)螺桿軸向剛度 Ks：從軸向剛度改變導(dǎo)螺桿的扭 轉(zhuǎn)剛度 Kn：螺母剛度 Kb：軸向載荷 Kh：軸承座機軸承架螺母的剛度 Kd：螺母連接塊軸向剛度 這是部分的 分析和計算的剛 性。 4.2.1 壓電陶瓷剛度 本文用壓電陶瓷微定位是打 印的 WTYD0808055 陶瓷生產(chǎn)的中國電子科技集團公司先研究所。通過它的剛度測量實驗 15.15N /m,如圖 4 4.2.2 接觸表面的接觸 剛度、摩擦塊之間的套筒 兩個物體互相接觸將在以前的某些行動切向相對滑移過渡切向外部力量，這被稱為預(yù)位移。力和位移之間的比例關(guān)系，實際上反映了一個剛性的特點。相應(yīng)的剛性現(xiàn)在是： K：常數(shù) N：正壓力 R： 對摩擦半徑的理想化的球體 表面 很明顯的 ,特殊摩擦方程出 發(fā) ,得到了齒輪傳動系統(tǒng)、鉀是由實驗 ,r 是常量 ,唯一的影響 動人的剛性因素常壓 N .很明顯 ,更大的 N、較大的接觸剛度 K。 圖 4:剛度曲線的壓電陶瓷 4.2.3 軸向剛度的改變 ,從扭轉(zhuǎn)剛度的導(dǎo)螺桿 傳動鏈方面的需要進行改造時統(tǒng)一計算它的剛性。因此，扭轉(zhuǎn)剛性必須轉(zhuǎn)換成下面的公式軸向剛度： 是 螺旋上升的鉛角，（） ； D 是絲桿直徑， mm； F 是絲桿軸向力 ,N； M 是絲桿輸入時刻， N mm； 是 在絲桿和螺母之間的摩擦角，（） ； 是 對絲杠扭轉(zhuǎn)剛度， Nmm/rad； 是 絲杠扭轉(zhuǎn)， rad P 是絲桿長度， mm； G 是絲桿剪切彈性模量， Mpa； 是 截面慣性矩， mm L 是兩個推力軸承的距離， mm 螺母連接的剛性塊軸向可以得到的有限元分析。螺母支架的剛度和軸承塊是非常大的，可以予以辭退。其他部分可以得到剛性通過查找表和計算。總之，通過演繹著驅(qū)動進給機構(gòu)的剛性方程，我們已經(jīng)找到了影響因素每一次駕駛駕駛部分，它提供了有關(guān)駕駛特性研究的基礎(chǔ)上進一步造成剛性。 5.進刀機構(gòu)的實驗研究 5.1 實驗系統(tǒng)的基礎(chǔ) 如圖 5 所示，該實驗系統(tǒng)是由送料機構(gòu)，計算機，壓電陶瓷驅(qū)動器其電源供應(yīng)器及電感測微儀。 圖 5:基礎(chǔ)的實驗系統(tǒng) 本文采用一種基于平均控制 曲線模型建立開環(huán)控制模型。首先 ,實驗曲線測量壓電陶瓷控制電壓之間的關(guān)系和滑動運輸距離。利用 Matlab 軟件以適應(yīng)線 ,以三次代數(shù)多項式擬合線 ,線擬合誤差 ,是一樣的顯示在圖 6,由此我們得到相應(yīng)的關(guān)系表達式的控制電壓和距離和因此控制距離的進給機制。 圖 6:適合以三次代數(shù)多項式 控制電壓和距離的關(guān)系式公式 7 所示 x 是輸出的距離 ,m； u 控制電壓 ,V。 5.2 實驗研究系統(tǒng)分辨率 如圖 7,壓電陶瓷具有一定的伸長。 就在這個時候 ,距離工作表微 0.15m。 然后一步拉伸逐漸在此基礎(chǔ)上 ,保持 1.5 在每一時刻。 采樣時間是控寄