機械設計外文翻譯-動態(tài)優(yōu)化的一種新型高速高精度的三自由度【中文4200字】【PDF+中文WORD】

機械設計外文翻譯-動態(tài)優(yōu)化的一種新型高速高精度的三自由度【中文4200字】【PDF+中文WORD】,中文4200字,PDF+中文WORD,機械設計,外文,翻譯,動態(tài),優(yōu)化,一種,新型,高速,高精度,自由度,中文,4200,PDF,WORD 【中文4200字】動態(tài)優(yōu)化的一種新型高速，高精度的三自由度機械手彭蘭（蘭朋），魯南立，孫立寧，丁傾永(機械電子工程學院，哈爾濱理工學院，哈爾濱 150001，中國)( Robotics Institute。Harbin Institute of Technology，Harbin 150001，P。R。China) 摘要介紹了一種動態(tài)優(yōu)化三自由度高速、高精度相結合，直接驅動臂平面并聯(lián)機構和線性驅動器，它可以提高其剛度進行了動力學分析軟件ADAMS仿真模擬環(huán)境中，進行仿真模擬實驗.設計調查是由參數(shù)分析工具完成處理的，分析了設計變量的近似的敏感性，包括影響參數(shù)的每道光束截面和相對位置的線性驅動器上的性能.在適當?shù)姆绞较?，模型可以獲得一個輕量級動態(tài)優(yōu)化和小變形的參數(shù)。一個平面并聯(lián)機構不同截面是用來改進機械手的.結果發(fā)生明顯的改進后的系統(tǒng)動力學仿真分析和另一個未精制一個幾乎是幾乎相等.但剛度的改進的質量大大降低，說明這種方法更為有效的。關鍵詞: 機械手、ADAMS、優(yōu)化、動力學仿真0 簡介并聯(lián)結構機械手（PKM）是一個很有前途的機器操作和裝配的電子裝置，因為他們有一些明顯的優(yōu)勢，例如：串行機械手的高負荷承載能力，良好的動態(tài)性能和精確定位的優(yōu)點等. 一種新型復合3一DOF臂的優(yōu)點和串行機械手，也是并聯(lián)機構為研究對象，三自由度并聯(lián)機器人是少自由度并聯(lián)機器人的重要類型。三自由度并聯(lián)機器人由于結構簡單，控制相對容易，價格便宜等優(yōu)點，具有很好的應用前景。但由于它們比六自由度并聯(lián)機器人更復雜的運動特性，增加了這類機構型綜合的難度，因此對三自由度并聯(lián)機器人進行型綜合具有理論意義和實際價值。本文利用螺旋理論對三自由度并聯(lián)機器人進行型綜合，以總結某些規(guī)律，進一步豐富型綜合理論，并為新機型的選型提供理論依據(jù)，以下對其進行闡述。如圖-1所示 機械手組成的平面并聯(lián)機構(PPM)包括平行四邊形結構和線性驅動器安裝在PPM.兩直接驅動電機c整合交流電高分辨率編碼器的一部分作為驅動平面并聯(lián)機械裝置.線型致動器驅動的聲音線圈發(fā)動機.這被認為是理想的驅動短行程的一部分.作為一個非換直接驅動類，音圈電機可以提供高位置敏感和完美的力量與中風的角色，高精密線性編碼作為回饋部分保證在垂直方向可重復性。另一方面，該產品具有較高的剛度比串行機械手，因為它的特點和低封閉環(huán)慣性轉矩。同時，該系統(tǒng)可以克服了柔性耦合力學彈性、齒輪、軸承、被撕咬支持，連接軸和其他零件，包括古典驅動設備，因此該機械手是更容易得到動力學性能好、精度高。圖-1 3自由度的混合結構的機械手當長度的各個環(huán)節(jié)的平面并聯(lián)機時，構決定于運動學分析和綜合4-7，機械優(yōu)化設計的首要任務，應加大僵硬、降低質量.關于幾個參數(shù)模型.這是它重要和必要的影響，研究了各參數(shù)對模型表現(xiàn)以進一步優(yōu)化。本文就開展設計研究工具，通過參數(shù)分析亞當斯，又要適當?shù)姆绞絹慝@得一個輕量級的優(yōu)化和小變形系統(tǒng)。1 仿真模型ADAMS(Automatic Dynamic Analysis 0f Mechanical System)自動機械系統(tǒng)動力學分析是一個完美的軟件，對機械系統(tǒng)動力學模擬可處理機制包括有剛性和靈活的部分，仿真模型可以創(chuàng)造出機械手的亞當斯環(huán)境 如圖-2。OXYz是全球性的參考幀，并OXYz局部坐標系，兩個直流驅動電機、交流和02M O1A表示，與線性驅動器CH被視為剛性轉子轉動慣量電機傳動的120kg/cm2。大眾的線性驅動器是1.5kg，連接AB、德、03F和LJ被視為柔性體立柱、橫梁GK，通用公司和公里，形成一個三角形，也被當作柔性傳動長度的鏈接是決定提前運動學設計為AB =O3F = 7cm，DE=IJ=7cm，GK= 7cm，GM =11.66cm， = 8.338cm。其它維度，這個數(shù)字是01A = 02M =7cm，CB=CD=HJ 2.5cm。EF=EG=JK= 3cm。 雖然總平面并聯(lián)機構的運動都是在水平、垂直和水平剛度必須在豎向剛度特征通常低于水平僵硬，因為它的角色在垂直懸臂梁的截面尺寸計算每一束平面并聯(lián)機構和相對位置的線性驅動器是兩個非常僵硬的影響因素的系統(tǒng)。運動支鏈可分為三類：主動鏈（由驅動器賦予確定獨立運動的支鏈。一般是單驅動器控制一個自由度的運動），從動鏈（不帶驅動器、被迫作確定運動的支鏈。又分為以下兩種：約束鏈：獨立限制機構自由度的從動鏈。冗余鏈：重復限制機構自由度的從動鏈）復合鏈（有單驅動器、但限制一個以上的機構自由度的支鏈，實際是主動鏈與約束鏈的組合）-并聯(lián)機構是由這幾種支鏈用不同形式組合起來的。動鏈中的約束鏈除了可以提高機構剛度和作為測量鏈外，其更主要的作用是用來約束動平臺的某一個或幾個自由度，以使其實現(xiàn)預期的運動。 圖-2 仿真模型2 仿真模擬結果在本節(jié)中，平均位移的末端是用來描述動態(tài)剛度，這是在不同的配置在不同的線性驅動器向前，從最初的位置的目的地，一般的豎向位移的機械手是作為目標來研究豎向剛度，平均差別的橫坐標、縱坐標點之間有一個剛性數(shù)學模型，模型，作為目標來研究水平剛度。并聯(lián)機器人的構型設計即型綜合是并聯(lián)機器人設計的首要環(huán)節(jié)，其目的是在給定所需自由度和運動要求條件下，尋求并聯(lián)機構桿副配置、驅動方式和總體布局等的各種可能組合。國內的許多學者正致力于這方面的研究，其中比較有代表性的有如下幾種方法：黃真為代表的約束綜合法；楊廷力等人的結構綜合法；代表的李代數(shù)綜合法。以上各種方法自成體系，各有特點，都缺乏理論的完備性。本文提出添加約束法，是從限制自由度的角度出發(fā)，增加約束，去除不需要的自由度，因每條主動鏈只有一個驅動裝置，讓其控制一個自由度，其余自由度通過純約束鏈去除，這樣可以使主、從動運動鏈的作用分離，運動解耦，有利于控制。具有三自由度的并聯(lián)機床，當采用條主動支鏈作為驅動時，機構就需要約束另三個自由度，通過選擇無驅動裝置的從動鏈來完成，則整個機構成為有確定運動的三自由度的并聯(lián)機構。黃真等提出的約束綜合法對完全對稱的少自由度并聯(lián)機器人機構進行了型綜合，完全對稱的支鏈結構相同，都屬于復合鏈，每條支鏈除都有一個單驅動器，控制一個自由度外，還應約束一個以上自由度才能使機構的六個自由度全部受控，使機構有確定的運動。2.1 截面效應扭轉變形位移的連結將會引起的，所以，扭轉常數(shù)的橫截面，重力是研究裝系統(tǒng)來研究，采取扭轉剛度的垂直切片lxx不變的各個環(huán)節(jié)和梁作為設計變量的變化，從 0.1 x 105mm4 與 3.5 x 105 mm4。圖-3 不斷的效果在垂直變形扭轉圖-3顯示了平均位移與截面扭轉常數(shù)末端的各個環(huán)節(jié)和梁，根據(jù)它的變化速率的環(huán)節(jié)，是最大的，AB是鏈接，LJ依次分別GK梁和KM有在豎向剛度性能。其他的仿真結果表明，水平位移之間的差異進行比較，結果表明該模型體育智力H和剛性模型變化小就改變了恒定不變的時候扭加載慣性力的線性驅動器，但是水平位移的變化，這意味著在這種模擬豎向變形的生產水平位移系統(tǒng)機械手。注意端面線性驅動器的主要原因是水平變形、線性驅動器機器人是由兩個節(jié)點C和H . 所以，我們計算了不同的Z-coordinate攝氏度之間，如圖所示，在圖4 -扭轉常數(shù)的影響差別的鏈接德。其次是最有效的通用和連接梁，連接O3F，梁GK有效果。因此，應采取AB和連接區(qū)段大扭常數(shù)的免疫力，豎向剛度較大并行扭轉不變的鏈接德也使較少的均勻性，降低線性驅動器不可以降低水平變形。圖-4 在不影響扭不變如圖-5、6所展示的影響是區(qū)域慣性轉矩的設計變量是區(qū)域剛度和慣性轉矩的各個環(huán)節(jié)和梁lz，圖顯示增加lw卡爾減少的速度高于垂直位移的不斷增加Ixx扭轉。這個Yxx AB、梁的鏈接，鏈接O3F是Iyy三個主要因素決定了豎向剛度。圖-6 所示 鏈接的AB、梁公里，連接03F也是其中的三個主要因素決定的均勻性線性傳動裝置、不同的分析結果表明，Izz效果好，具有至少兩個垂直和水平剛度，這意味著這種結構，具有足夠的水平，降低Izz剛度的鏈接和增加Iyy AB、梁的鏈接，鏈接O3F公里的好方法，優(yōu)化系統(tǒng)。圖-5 瞬間的慣性效應對垂直位移圖-6 轉動慣量不平衡的影響2.2影響的線性驅動器的相對位置線性執(zhí)行器的慣性是主要載荷之一，在機械手的運動，不同的相對應的垂直位置產生不同的變形，圖7顯示了絕對平均的最終效應垂直位移時驅動馬達以恒定的加速度旋轉，我們可以看到，過低或過高的相對位置會造成比格變形，最好的位置是一對Z = 24毫米的地方大概是從中間環(huán)節(jié)連接O3F到 AB.圖-7 影響線性驅動器的相對位置3 分析改進的機械手根據(jù)上述模擬結果，所有改進的機械手的設計，時間如下：鏈接截面AB，DE，lJ 與30mm的基礎和高度，10毫米的厚度;鏈接O3F和矩形空心梁與30mm的基礎和高度工型鋼，l0mm法蘭和6mm網(wǎng);梁競，通用汽車與8mm的堅實基礎和30mm高的矩形。圖-8 梯形運動姿態(tài)圖-9中回應的是機械手，相比之下，圖-10中提高初始的反應，在其中所有的鏈接和機械手的矩形截面梁的堅實基礎，用30毫米，高度的差異是曲線，C和H的曲線積分，二是垂直位移的末端，改進系統(tǒng)中最大位移0.7Um最初的0.12Um相比，爭論的振動激勵后仍停留在O.06Um0.15% sO.05Um相比的初始變形改善系統(tǒng)的初始小于前者具有較少的慣性，因為在相同的步伐不斷加快，保持振動瓣膜差不多一樣，它對這整個系統(tǒng)中來說，仍然改善系統(tǒng)的剛度，幾乎相當于初始制度，針對大規(guī)模的平面并聯(lián)機構在該系統(tǒng)相比下降了30%，這樣的初始優(yōu)化是有效的。 圖-9 、 圖-10 動態(tài)響應4 結論本文設計了一種新型三自由度機械手變量的敏感性進行了研究在ADAMS環(huán)境中，可以得出以下結論：1） 機器人具有較大的水平剛度，最終水平位移，效應主要是由機械手垂直變形造成的，因此，更重要的是增加的幅度比剛度豎向剛度。2） 參數(shù)Ixx，Iyy并鏈接截面剛度Izz有不同的效應，Iyy已經對垂直剛度的影響最大，Ixx在第二位的是，Ixx具有在垂直剛度的影響最小，他們都較少對水平比垂直剛度剛度。3） 橫截面的不同環(huán)節(jié)都有不同的影響，連線豎向剛度AB和德應該使用區(qū)扭轉常數(shù)和慣性力矩大，如變形、長方形、橫梁KM，線 03F應該使用區(qū)段形梁等重大時刻轉動慣量、橫梁GK，和GM 可以使用盡可能的一小部分，從而降低了質量。4） 最佳的線性驅動器的相對位置可以減少變形，最好的位置是垂直的平行結構。5） 改進的機械手的動態(tài)分析表明該優(yōu)化設計方法研究的基礎上的效率。參考文獻 l Dasgupta B，Mmthyunjayab T S。 The Stewart platform manipulator：a review。Mechatm and Machine Theory，200o。35 (1)：1540 2 Xi F，Zhang D，Xu Z，et al。A comparative study on tripod u ts for machine Lo0ls。Intemational Journal of Machine TooLs&Manufacture，2003，43(7)：721730 3 Zhang D，Gosselin C M。Kinetostatic analysis and optimization of the Tricept machine tool family。In：Proceedings of Year 2000 Parallel Kinematic Machines International Conference，Ann Arbor，Michigan ，2001， 174188 4 Gosselin C M，Angeles J。A globe preference index for the kinematic optimum of robotic manipulator。ASME Journal of Mechanical ，l991，113(3)：220226 5 Gao F，I，iuX J，GruverW A。Performance evaluation of two-degree-of-freedom planar parallel robots。Mechanism and Machine Theory，l998，33(6)：661-668 6 Huang T，Li M，Li Z X，et al。Optimal kinematic design of 2- DOF oaralel manipulator with well shahed workspace bounded by a specified conditioning index IEEE Transactions of Robot and Automation，2004，20，(3)：538543 7 Gosselin C M，Wang J。singularity loci ofplanarparallel manipulator with revoluted actuators。Robotics and Autonomousm，1997，2l(4)：377 398 8 Yiu Y K，Cheng H，Xiong Z H，et al。on the dvnamies of Parallel Mmfipulators Proc。Of IEEE Inemational conference on Robotics& Automation。20o1。3766 3771 9 Chakarov D。Study ofthe antagoniie stifness of parallel manipulators with actuation redundancy。Mechanism and Machine Theory，2004，39(6)：58360l 10 Shaba A A。Dynamics of Multibody systems。 Cambridge：Cambridge university press，l998。270-3 l011維普資訊 http:/www.cqv1p.comHIGH TECHNOLOGY LEITERS IVol. 12 No. 1 1 Jan. 2)663Dynamics optimization of a novel high speed and high precision 3-DOF manipulatorLan Peng （蘭朋悶，U Nianli , Sun Lining 鈴 ，Ding Qingyong 費( School of Me.chatroni 臼 Engineering, Har也m Institute of Te丁hnology, Harbin 15刷 ，P . R .China) ( Robotics Institute, H缸bin Institute of Technolo町，Harbin 15僅見I , P.R.China)Absti古董ctAfter introducing a novel 3-DOF high speed and high precision manipulator which combines direct driven planar parallel mechanism and linear actuator, ways of increasing its stiffness a陀 studied through dynamics simulation in ADAMS softw缸它 environment . Design study is carried out by parametric analysis tools to analyze the approximate sensitivity of the design V缸iables , including the effects of p缸沮netens of each beam cross section and relative position of linear actuator on model performance. Conclusions a陀 drdwn on the appropriate way of dynamics optimization to get a lightweight and small deformation manipu lator. A planar parallel mechanism wi出 different cross section is used to an improved manipulator. Resuits of dynamics simulation of the improved system and another unrefined one 缸e compa配d . 1e sti旺ness of them is almost equal , but the mass of 由e improved one decreas臼 greatly , which illustrates the ways efficient .Key words: manipulator, ADAMS, optimization , dynamics simulation0 IntroductionParallel kinematic manipulatons ( PKM ） 耐 a class of promising machine for the manipulation and assemble of electronic device, because they have some advantagesover the serial manipulator, such as high load ca町ing capacity , g0對 dynamic performance and precise position ing1l . A novel hybrid 3-DOF manipulator, which combines the advantages of parallel manipulator and serial manipulator, is studied in this paper. As shown in Fig. 1, the manipulator is composed of planar parallelmechanism ( PPM ) including parallelogram structure and linear actuator mounted on the end of PPM . Two A巳 di陀ct driven moto囚 integrated high 陀田lution emselected as driven part of planar par茍Ilel mechanism . Lln 回 actuator is driven by voice coil motor, which is con sidered as ideal driven part for short travel . As a kind of non-commutated di陀ct 世ive , hysteresis-free, cog-freedevice, voice coil motor can provide both high 歸sition sensitivity 阻d pert叩force vensus stroke character. Hi班precision linear encoder is used as feedback parts to 伊ar ante悟 出e 陀陰暗tability in vertic況Idirection .Compared with higher degree of freedom parallel manipulator, for example Steward platform or Tricept robot , kinematic and d嚴1amic m叫els of PPM ar吃 simple i-3 _On the other hand , it has higher stiffness 由m 出e serial manipulator because of its close loop feature and low mo ment of inertia . Meanwhile, the system can ove陀ome the mechanical elasticity introduced by flexible coupling, gear teeth, be白噸，bearing support , connecting shaft and other parts included by classical drive system . So this ma nipulator is more easily to get well dynamics perfonnance and high p即ision .Planar parallel mechanismMotorFig.1 3-00F hyhrid structUJ它 manipulatorWhen the length of each link of pl四ar parallel mechanism is d配ided by kinematics analysis and syn出e sis4-7l , the primary task of optimal desi伊 should be in creasing the stiffness and dee陀asing 由e mass. With re gard to model wi由several par淚neters, it is important and咀1at makes real time control possible and is mo陀 precise .neeesry to study the influence of each pneter on田缸田 Supported by 配 High Technology Research and Development Pr咱出nme of China ( No. 2003AA刷刷） To whom co呵lOndence 動 uld be addressed . E而 mail: l皿 p sma. 凹陽Ri,cpjved on Sept. 29，刻Xl4維普資訊 h吐p:/www .叫v1p.com641-DGH TECHNOLO(,Y LF.ITERSI Vol.12 No. I I Jan. 2(脅model performance in order tu make fu出er optimization . This paper will carry out design study by parametric anal ysis tools of ADAMS, and then p陀sent appropriate ways of optimization to get a lightweight and small deformation system .1 Simulation modelADAMS ( Automatic Dynamic Analy附 of Mechanical System) is a perfect software tool for dynamics simulation of mechanical system . It can deal with mechanism con sisting of both rigid and flexible parts . Simulation model of the manipulator can be created in the ADAMS environ ment as shown in Fig.2. OXYZ is the global referenceframe , and o.切:yz is local reference frame. Two AC directdriven motors, expressed as 01A and Oi M , and linear actuator CH are t陀ated as rigid 以,dy . 幣1e rotor inertia of motor is 120kg cm2 . 幣1e mass of linear actuator is 1.5kg. Links AB, DE, 03F and U are tr臼ted a,; flexibleeffector is used to characterize the dynamic stiffness, which is different at different configuration during the linear actuator moving fmward from initial position to the destination . 咀1e average vertical displacement of the end effector is taken as the ob ective to study vertical stiff n白白. The average difference of X-coordinate and Ycoor dinate of point H between 由is model and a rigid model is 時cen as the objective to study level 叫iffness.2 .1 Effect of er鴨 ”ction。Torsion defonnations of links will cause vertical dis placement of the end-effector. So, torsional constants of cross section are studied first . Gravity is loaded on the system to study the vertical stiffness . Take torsional con stant f section of each link and beam as design vari able which varies from 0.1 x la5mm4 to 3 .5 x Ia5mm4 . Fig. 3 shows the average displacement of 由e end-effectorbody. Beam GK , GM and KM , which form a triangle,即e also treated as flexible body . The length of links a陀 decided in advance by kinematics design a,; AB 的F 7cm, DE = IJ = 7cm , GK = 7cm , GM = 11.66cm, KM =8.338cm . 響1e other dimensions in the figure a陀 01 A =02 M = 7cm, CB = CD = HJ : 2.5cm , EF = EC = JK =3cm.Although the gross motion of planar parallel mecha nism is in level, ho由 the vertical and level stiffness has to be considered . And the vertical stiffness is usually less than the level stiffness because of its cantilever characterin vertical plane. 咀1e cross section size of each beam of-0.00相r句Q士、 -0. 0013。”，-0.004。四-0.00咀-0.007。由17。惜0.00 $，- 壺1-link 03F2-link AB3-link DE且也日5-beam GK6一戰(zhàn)am GM7 斗:,eam KM，。 52.02.53.03.6T惆ional cons陽ts (105mm勺planar parallel mechanism and the relative position of lin ear actuator 缸e two important factors that affect the stiff ness of the system. Therefore, the following study is done in these respects .Fig.2 Simulation mudd2 Simulation r四時tIn this section , the average displacement of the end-Fig. 3 Effect of torsional constant on vertial deformationversus cross section torsional constant of each link and be卻n . According to it , the change rate of link AB is the biggest . Next is link DE ，日in tum res嚴ctively . B創(chuàng)ms GK and KM have the least eff白t on vertical stiffness. Other simulation shows that level displacement differenceof point H between this model and a rigid model changes little with respect to a change in the torsional constant when constant level inertia force is loaded on the linear actuator. But the level displacement of the end-effector changes in 出is simulation . 1at means vertical deforna tion of the system should produce level displacement of end回effector. Note that unevenness of the linear actuator is the main cause of level defonnation of end-effect肘，and the linear actuator is supported by two joints C and H. So we calculate the difference of Z -coordinate between 陽int C and H . As shown in Fig. 4, torsional constant of link DE affects the difference 出e most efficiently . Next is k田n GM and link U in order. Link 03F and beam GK have the leai;t effect .咀1erefore, links AB and DE should adopt se;tion維普資訊 h即八ilWW.cqv1p .comHIGH TECHNOLC見Y IEITERSI Vol.12 No. l lJan. 2)665with big torsional constant to enhance the vertical stiff ness. Bigger torsional constant of link DE also caus臼less unevenness of the linear actuator . Decreasing the uneven ness can reduce the level deformation .2-link ABstant 四e Irr of link AB , beam KM and link 03F are 出e three main factors that decide the vertical stiffness. Fig. 6 shows the Irr of link AB , beam KM and link 03F缸它 also the three main facto陀 that decide the unevenness of the linear actuator. Di征erent analysis shows that I, has the least effect on b 由 vertical and level stiffness . 幣iatmeans this kind of structure has enough level stiffness. So4一UnmkUGMdasing I, of links and increasing” of link AB,be晦配陀beam KM and link 03F 缸它 the good ways to optimize the system .2.2Effect of the relative position of linear ac陽ator3.73.6QO0.51.01.52.02.53.。 3.5Torsional constants (1l?mm4)1e inertia of linear actuator is one of the main loads during the motion of manipulator . Different relative ve民i cal position should produce different deformation . Fig. 7Fig.4 Effect of torsional constant on unevennessWhat Fig聲 .5 and 6 show are the effects of areamG（EE一守LD己 言ERE昏時唱g 百多.0.J05shows the absolute average vertical displacement of end effector when the driven motors rotate at a constant acceleration . We can see that too low or too hi班 時ative position will cause bigger defonnation 咀1e best position is at a如ut Z = - 24mm where is approximate the midst from link AB to link 03F.mE。6mA.0.0025。4一link u6 beam GM0.51.01.5Moments of iner由（llfmmJdO D41lAB亞 刷Eu2.02.5Fig.5 Effect of moments of i陽rtia on vertial defo回國lion。0.0-J.0-40.0.10.0Z-coordinate (mm)篇。eoo1 ink 03F 3-link DE 5一悅am GK2一link:AB4-link 日6-bE姐m GMFig.7 Effect of relative position of linear actuator3-5乙回南.：.乓芫叫. 、3Analysis of an improved manipulatorAccording to above simulation result , an improved manipulator is designed as follows : cross s創(chuàng)ions of linksAB , DE ，日在附 hollow rectangle with 30mm b出e and2.5 0.00.51.01.52.02.5height , 10mm thickne制；link 向F and beam KM 町e IMoments of inertia (105mm）Fig. 6 Effect of moments of inertia on unevennessmoment of inertia on the stiffness. lbe design variable is 臟a moment of inertia lyy and of each link and beam . Fig. 5 shows that inc陀兇e of Irr can 配duce the vertical deformation more rapidly than increase of torsional con-beam with 30mm baie and height , I 0mm flange and 6mm web; beams CK , GM a陀 solid rectangle with 8mm baie and 30mm height.Trapezoidal motion profiles shown as Fig .8 ar它 used as the excitation of simulation , wher curve I is for both motors while curve 2 is for linear actuator .維營資訊 h即www.cqv1p.com66aEE h有EZZ口口nuhu鳴44面刀口口。0 0083 4。000.口.（0.08口1201BTlme / s日軍.8 Trapezoidal motion profileFig. 9 is the 配sponse of 由e improved manipulator . In comparison , Fig. 10 is the response of an initial manip ulator in which all links and beams are of solid rectangle section M出30mm base and height . Curve 1 is the differ ence in Z-coordinate between points C and H. Curve 2 is the vertical displacement of 出e end-effector . 咀1e maximum vertical displacement of improved system is O. 7rn。因1。-0田l05HIGH TECHNOIGY IEITERSI Vol.12 No. l lJan. 2厄the initial one because the former has less inertia at the same acceleration . 咀1e remained vibrations are almost similar. It means that the stiffness of improved system isalmost equal to the initial system . In view of that mass of the planar parallel mechanism in this improved system de C陀ase 30 pe陀ent compared with the initial one, this way of optimization is efficient .4 ConclusioinIn this paper, design sensitivity study of the variable of a novel 3-DOF manipulator is carried out in ADAMS environment .咀1e following conclusions can be drawn:1) The manipulator has big level stiffness. The level displacement of end-effector is mainly caused by vertical deformation of the manipulator . Therefore it is more im portant to increase vertical stiffness than to increase level stiffness.2) TI1e parameters I 口，lyy and of links crosssection have different effect on stiffne盹 lyy h掘 出e great est effect on vertical stiffness , and is in the second place. I, has the least effect on vertical stiffness . All of them has le崎 effect on level stiffness than on vertical stiff- ness.3) Cross section of different link hal different effect on the vertical stiffnes呂. links AB and DE should use section with big torsional constant and moment inertia ( lyy ) such as circler, rectangle. Beam KM and link 03F should use section with big moment inertia ( lyy ) such 出I-beam . Be嘟丑 GK and GM can use a small section 出0.005。例。國Tune (s)日軍，9 Dynamics response0.120.16possible in order to decre部e the mass.4) An optimal relative position of linear actuator can reduce the deformation .咀1e best position is about verticalmidst of the parallel structure .5) The dynamic analysis of an improved manipulator。001illustrat回this optimization way baled on the design studyefficient .百E餌m-0.0015o.oa刷0080.120.16Time (s)Fig.10 Dynarr世cs 陀sponsecompared 白白0. 12/.illl of the initial one. The a電ument of remained vibrations after excitation stop at O. 15呂 is about 0.06陽n compar叫陽出 0.05rn of the initial one. The deformations of improved system are less thanReferences 1 Dasgupta B, Mn血yunjayab T S. The Stewart platform manip ulator: a review. Mechanism aml Machine Theo巾，2000, 35 ( 1 ) :15-40 2 Xi F, Z問D, Xu Z, et al. A comparative study on tripodunits for machine tools. lruemntin阻d Journal of MachinP Tools & Manufacture , 2003, 43(7) :721-730 3 Zhang D, Gosselin C M. Kinetostatic analysis and optimiza tion of the Tricept machine tool family. In: Proceedings of Year 篤陽） Parallel Kinematie Machines International Confer ence, Ann Arbor, Michigan, 2001 . 174-188 4 Go附Jin C M, A噸eles J. A globe p配ference index for 出e kinematic optimum of robotic manipulator. ASME Jounw.l (if Mechanical Design , 1991 , 113 (3) :2:卻 226 5 Gao F, Liu X J , Gruver W A . Performance evaluation of tw，仆degrt雪非of-freedom planar parallel robots. Mechanism aml Mchine Theory , 1998, 33( 6） ：“1-668維營資訊 h即www.cqv1p.comHIGH TECHNOLOGY lEITERSI Vol.12 No. I I Jan. 2)667 6 Huang T, Ll M , Ll Z X，儼t al. Optimal !cinematic design of 2-DOF parallel manipulator with well sha陽i workspace bounded by a specified conditioning index. IEEE Tran.sac twns of Robotu:.s and Autonwlwn , 2僅)4, 20, (3) :538-543。 7 Go酣Jin C M , Wang J. Singularity loci of planar parallel ma nipulator m由 陀voluted actuators. Robotu:s and Auwnonwus. 。寫ystems , 1997, 21 ( 4) :377-398 8 Yiu Y K, Cheng H, Xiong Z H, et al . n the dynamics of Parallel Manipulators Proc f IEEE lnernational conference on Robotics & Automation, 2001. 37(:Jj”3771 9 Chakarov D. Study of the antagonistic stiffness of parallel ma nipulators wi由 actuation redundancy. Mechanism and Ma chine Theo廳 ，2僅l4, 39( 6) :583-60110 Shabana A A. Dynamics of multibody systems. Cambridge: Cambridge 田咀versity p回，1998, 270-310 11 Haug E J . Computer Aided Kinematic and Dynamics of Me chanical System. Allyn and Bacon. 1989, 1-1112 Lu Youfang. 問namics of Flexible Multibody Systems. Beijing: Higher Education 階ess. 1996, 58-274 (in Chinese)Lan Peng, born in 1971 . He received his Ph . D degr啊 in School of Mechatronic Engineering in Harbin Institute of Technology in 2005 . He also received his B.S. and M . S. degrees from Harbin Jianzhu University in1993 and 1996 陀spectively . His research interests in elude dynamics of flexible mutibody systems , structure 劇alysis of mechanism , stability 陽alysis of beam system 劇d design of construction machinery .