機(jī)械設(shè)計(jì)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(jī)械設(shè)計(jì)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(jī)械設(shè)計(jì),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
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(fèi)( 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(yán)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(yán)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 .
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