喜歡這套資料就充值下載吧。資源目錄里展示的都可在線預(yù)覽哦。下載后都有，請放心下載，文件全都包含在內(nèi)，圖紙為CAD格式可編輯，有疑問咨詢QQ:414951605 或 1304139763p 摘 要 氣動(dòng)機(jī)械手是以氣壓為驅(qū)動(dòng)力的機(jī)械手。機(jī)械手并不是在簡單意義上代替人工的勞動(dòng)，而是綜合了人的特長和機(jī)器特長的一種擬人的電子機(jī)械裝置，既有人對環(huán)境狀態(tài)的快速反應(yīng)和分析判斷能力，又有機(jī)器可長時(shí)間持續(xù)工作、精確度高、抗惡劣環(huán)境的能力，它主要是用以按固定程序抓取、搬運(yùn)物件或操作工具的自動(dòng)操作裝置。所以氣動(dòng)機(jī)械手能夠降低勞動(dòng)強(qiáng)度，提高生產(chǎn)效率。但它的缺點(diǎn)也很明顯，因?yàn)闅怏w具有很大的可壓縮性, 要做到氣動(dòng)機(jī)械手精確定位難度很大, 尤其是難以實(shí)現(xiàn)任意位置的多點(diǎn)定位；而且可壓縮性也帶來不能承受過重的負(fù)載的限制。傳統(tǒng)氣動(dòng)系統(tǒng)只能靠機(jī)械定位置的調(diào)定位置而實(shí)現(xiàn)可靠定位, 并且其運(yùn)動(dòng)速度只能靠單向節(jié)流閥單一調(diào)定, 經(jīng)常無法滿足許多設(shè)備的自動(dòng)控制要求。 本課題經(jīng)過深刻的研究發(fā)現(xiàn)，目前生產(chǎn)線上的氣動(dòng)翻轉(zhuǎn)機(jī)械手一個(gè)運(yùn)動(dòng)進(jìn)程只能實(shí)現(xiàn)一次抓取和翻轉(zhuǎn)功能的，感覺這種機(jī)械手效率太低。所以本次設(shè)計(jì)針對這個(gè)缺點(diǎn)，設(shè)計(jì)出了一種氣動(dòng)翻轉(zhuǎn)機(jī)械手，它在一個(gè)運(yùn)動(dòng)進(jìn)程能實(shí)現(xiàn)兩次抓取和翻轉(zhuǎn)，提高了工作效率，加快生產(chǎn)效率。全文由五章構(gòu)成： 關(guān)鍵詞：氣動(dòng)裝置；機(jī)械手;翻轉(zhuǎn)裝置；夾瓶器； Abstract Pneumatic manipulator is a robot which is based on Pressure-driven. The robot is the combination of expertise and expertise of an anthropomorphic machine electro-mechanical device, not simply instead of manual labor. It owns both the rapid response to the environment state and the ability of a long continuous operation, high accuracy, and the resistance to harsh environments. It is mainly used to crawl at a fixed program, and carry objects and operate tools automatically. So Pneumatic Manipulator can reduce labor intensity, improve production efficiency. However, its disadvantages are obvious. Pneumatic Manipulator getting the precise positioning is very difficult, especially achieving multi-point positioning to anywhere because of the great compressibility of gas. Also, the compressibility limits a load to be too heavy. Traditional pneumatic system only relies on the set position of the mechanical giving location and reliable positioning and velocity which relies on a single one-way throttle. So it is often unable to meet many requirements of the automatic control equipment. After a deep study, we found that the pneumatic flip robot on the current production line can only be achieved crawling and flip function once in a movement process whose efficiency is too low. So we design a pneumatic flip robot which can achieve the two crawling and flipping in a motion process. There is no doubt that the pneumatic flip robot can improve work efficiency and speed up the production efficiency. Key words: pneumatic devices; robot; turning device; clip bottle; 目 錄 摘 要 Abstract 第1章 緒論 1 1.1 引言 1 1.2氣動(dòng)機(jī)械手的發(fā)展 1 1.2.1國外氣動(dòng)機(jī)械手狀況 1 1.2.2國內(nèi)氣動(dòng)機(jī)械手情況 3 1.3發(fā)展趨勢 3 1.3.1重復(fù)高精度 3 1.3.2模塊化 3 1.3.3無給油化 4 1.3.4 機(jī)電氣一體化 4 1.4 機(jī)械手夾持部件結(jié)構(gòu)示意圖 4 1.4.1 外夾持型機(jī)械手 4 1.4.2 內(nèi)夾持型機(jī)械手 5 1.5國內(nèi)外氣動(dòng)機(jī)械手設(shè)計(jì)舉例 5 1.5.1與模具切割相結(jié)合 5 1.5.2 機(jī)械手虛擬樣機(jī) 6 1.5.3 高精度機(jī)械手 6 第2章 氣動(dòng)翻轉(zhuǎn)機(jī)械手總體設(shè)計(jì) 8 2.1 抓取系統(tǒng)的初步設(shè)計(jì) 8 2.2 翻轉(zhuǎn)系統(tǒng)的初步設(shè)計(jì) 8 2.2.1 錐齒輪電機(jī)翻轉(zhuǎn) 8 2.2.2 鏈輪鏈條氣缸翻轉(zhuǎn) 9 2.2.3 翻轉(zhuǎn)方案選擇 9 2.3氣動(dòng)翻轉(zhuǎn)機(jī)械手的三維建模、裝配思路 10 2.3.1各部分零件設(shè)計(jì) 10 2.3.2 氣動(dòng)翻轉(zhuǎn)機(jī)械手的運(yùn)動(dòng)學(xué)仿真 10 2.3.3 研究思路方案、可行性分析及預(yù)期成果 11 第3章 氣動(dòng)翻轉(zhuǎn)機(jī)械手重要零部件設(shè)計(jì)校核及其裝配 12 3.1氣缸的設(shè)計(jì)和校核 12 3.1.1 夾緊系統(tǒng)氣缸設(shè)計(jì)和校核 12 3.1.2 翻轉(zhuǎn)系統(tǒng)氣缸設(shè)計(jì)和校核 14 3.2齒輪設(shè)計(jì)和校核 15 3.2.1齒輪參數(shù)的選擇 15 3.2.2齒輪幾何尺寸確定 15 3.2.3齒根彎曲疲勞強(qiáng)度計(jì)算 16 3.3齒條的設(shè)計(jì)和校核 18 3.3.1齒條的設(shè)計(jì) 18 3.4 固定機(jī)架上的軸設(shè)計(jì)和校核 20 3.4.1求輸入軸上的功率、轉(zhuǎn)速和轉(zhuǎn)矩 20 3.4.2求作用在齒輪上的力 20 3.4.3 初步確定軸的最小直徑 21 3.4.4軸的結(jié)構(gòu)設(shè)計(jì) 21 3.4.5精確校核軸的疲勞強(qiáng)度 23 3.5圓錐滾子軸承的設(shè)計(jì)和校核 25 3.6鍵連接設(shè)計(jì)和校核 26 3.6.1輸入軸鍵計(jì)算 26 3.6.2中間軸鍵計(jì)算 26 3.6.3輸出軸鍵計(jì)算 27 3.7聯(lián)軸器的設(shè)計(jì)和校核 27 第4章 三維建模和運(yùn)動(dòng)仿真 29 4.1 整體裝配圖 29 4.2夾緊系統(tǒng)裝配圖 29 4.3氣缸推動(dòng)和翻轉(zhuǎn)系統(tǒng)裝配圖 30 4.4 氣缸推動(dòng)夾緊裝置系統(tǒng)裝配圖 30 第5章 總結(jié)與展望 32 5.1總結(jié) 32 5.2展望 32 參考文獻(xiàn) 33 致 謝 35 International Journal of Machine Tools & Manufacture 46 (2006) 13501361Design and feasibility tests of a flexible gripper based oninflatable rubber pocketsHo Choi, Muammer Koc -?NSF ERC on Reconfigurable Manufacturing Systems, College of Engineering, University of Michigan, Ann Arbor, MI 48109, USAReceived 30 January 2005; accepted 19 October 2005Available online 5 December 2005AbstractIn this paper, we present feasibility test results of a flexible gripper design following a literature survey on various types, design andcontrol strategies of the existing grippers. A flexible gripper based on the use of compliant materials (i.e., rubber) with pneumaticinflation was designed, analyzed, built and tested. Parametric FE analyses were conducted to investigate the effects of process and designparameters, such as rubber material, pressure, initial jaw displacement and friction. Based on the FEA results, a simple, single rubber-pocketed flexible gripper was designed and built. Feasibility experiments were performed to demonstrate and obtain an overallunderstanding about the capability and limitations of the gripper. It was found that objects with different shapes (cylindrical, prismaticand complex), weight (50g20kg.), and types (egg, steel hemi-spheres, wax cylinders, etc.) could be picked and placed without any loss ofcontrol of the object. The range of positioning error for two different part shapes (i.e., prismatic or cylindrical) was found to be 2090mm(translational) and 0.030.91 (rotational).r 2005 Elsevier Ltd. All rights reserved.Keywords: Gripper design; Strategies; Flexible; Selection; Robotic; Rubber1. IntroductionA gripper is an end-of-arm tooling used on robots forgrasping, holding, lifting, moving and controlling ofmaterials whenever they are not processed. Human handshave been the most common, versatile, effective anddelicate form of material handling. But, for repetitivecycles, heavy loads and under extreme environments,grippers had to be developed to substitute for humanhands. In the 1960s, after the emergence of modern robots,grippers replaced human hands on numerous occasions.Robot-gripper systems are found to be effective forrepetitive material handling functions in spite of theirinitial capital and ongoing maintenance expenses becauseof their reliability, endurance and productivity. However,the cost of grippers may be as high as 20% of a robotscost, depending on the application and part complexity 1.For manufacturing systems where flexibility is desired, thecost of a suitable gripper may even go higher since theyrequire additional controls, sensors and design needs withregards to being able to handle different parts.In the 21st century, under the influences of globalization,manufacturing companies are required to meet continu-ously changing demands in terms of product volume,variety and rapid response. flexible and reconfigurablemanufacturing systems (FMS and RMS) have emerged asa science and industrial practice to bring about solutionsfor unpredictable and frequently changing market condi-tions 2. In order to fully realize the benefits of RMS andFMS, the grippers, being one of the few direct contactswith the product at the very bottom of the manufacturingchain, must also be designed for flexibility.In the early days of robotic technology applications,most grippers were designed for dedicated tasks, and couldnot be revised for other shape, size and weight conditions.Later on, a variety of flexible gripper designs weresuggested to overcome such drawbacks. But their highcost was a barrier in addition to maintenance issues andlimitations to few materials and applications. Despite suchARTICLE IN PRESS front matter r 2005 Elsevier Ltd. All rights reserved.doi:10.1016/j.ijmachtools.2005.10.009?Corresponding author. Tel.: +7347637119; fax: +6465147590.E-mail address: mkocumich.edu (M. Koc -).drawbacks, cost effective flexible gripper designs havebeen always sought as a viable solution for agile materialhandling systems as an important element of the envisionedFMS and RMS. For example, assembly operations inmany industries make extensive use of dedicated grippersand fixtures. These are part-specific, and therefore, must bemodified or replaced when model changes are introduced.The cost of redesigning, manufacturing, and installingthese grippers and fixtures is substantial (on the order of$100 million per plant per year for automotive manufac-turers) and would be significantly reduced if a more flexiblealternative was developed.Inthispaper,followinganextensivereviewanddiscussion on different gripper types and design issues inthe first section, a flexible gripper design based on the useof compliant materials and internal pressure (i.e., inflatablerubber pockets) approach is introduced in the second part.This type of grippers conforms to the shape of an object bymeans of elastic gripping elements and pressurization withactive degrees of freedom. In the third section, the resultsof a parametric FEA study are presented to characterizethe performance of the selected configurations of theflexible gripper under different loading and part conditionsto determine the proper parameters setting and thematerial. Finally, in the fourth section, following theprototyping, feasibility tests conducted to characterize thelimits and capabilities of the flexible gripper are explained.2. Literature survey on gripper design and types2.1. Design methodology of grippersWright et al. 3 compared the grippers to the humangrasping system, and categorized the design requirementsof grippers into (a) compatibility with the robot arm andcontroller, (b) secure grasping and holding of the objects,and (c) accurate completion of the handling task. Manyindustrial examples of grippers were also described, and theguidelines for gripper design were presented. Pham et al. 1summarized the strategies for design and selection ofgrippers in different application cases. In their study, thevariables affecting the selection of a gripper were listed as:(a) component, (b) task, (c) environment, (d) robot armand control conditions. The component variables includegeometry, shape, size, weight, surface quality and tempera-ture of objects to be handled. For reconfigurable systems,they divided these components into part families accordingto their shape and size. For the task variables, type ofgripper, number of different parts, accuracy, and cyclewere considered in addition to major handling operationssuch as pick, hold, move and place. For the right gripperdesign at the right place, all aspects should be considered,and multiple validation tests should be conducted. Toreduce this exhaustive effort, Pham et al. 4 developed anexpert system for selecting robot grippers. They built ahybrid expert system that employs both rule-based andobject-oriented programming approaches.2.2. Gripper types and classification by driving forceGrippers could be also classified with respect to theirpurpose, size, load, and driving force. Typically, grippermechanisms and major features are defined by their drivingforces. The driving forces for robot grippers are usuallyelectric, pneumatic, hydraulic; or in some cases, vacuum,magneto-rheological fluid and shape memory, etc.Grippers with electric motors have been used since 1960,abreast with robot technology. Many other grippersadopted motor driven mechanisms. Basically, this type ofsystems included step motors, ball screws, encoders,sensors and controllers. As the arms approach the object,distance, force, weight and slip are detected by sensors. Atthe same time, a controller regulates the force, speed,position and motion. Friedrich et al. 5 developed sensorygripping system for variable products. They used multiplesensors to measure the grasping force, weight and slip.Mason et al. 6 and Kerr et al. 7 presented thefundamentals of grasping with multi-fingered hands. Leeet al. 8 comprehensively reviewed the field of tactilesensing. For contact and slip, Tremblay et al. 9 consideredslip detection, and Howleg et al. 10 divided slip into fourstages; pre-slip tension, slip-start, post-movement, and stopto better analyze grasping of parts.Another way of actuating the robot gripper is throughpneumatic (or hydraulic) systems. Pneumatic systems havebeen developed because of their simplicity, cleanliness andcost-effectiveness. Warnecke et al. 11 and Wright et al. 3developed a soft pneumatic gripper which can handle softmaterials such as eggs. Ottaviano et al. 12 developedgrasp-force control in two-finger grippers with pneumaticactuation. They proposed force control in a two-fingergripper with a sensing system using commercial forcesensors. A suitable model of the control scheme has beendesigned to control thegrasping force.Experimentsshowed the practical feasibility of two-finger grippers withforce controlled pneumatic actuation 12. Lane et al. 13used hydraulic force for a sub-sea robot hand. They offerednaturalpassivecompliancetocorrectforinevitablepositioning inaccuracy with simple design and minimummoving parts. The gripper finger relied on the elasticdeformation of cylindrical metal bellows with thin con-voluted walls. The convolution ensured that the assemblywas significantly stiffer in the radial direction than thelongitudinal one. Therefore longitudinal extension wasmuch greater than radial expansion when subjected tointernalhydraulicpressure.Themodularfingertipcontained a variety of sensors and interfaces. The fingertip contact zone contains both a strain gage and apiezoelectric vibration sensor. Closed-loop position controlwas used. It was driven by hydraulic pressure measuredfrom sensors within each tube 13.Grippers based on vacuum forces are designed and usedmainly for deformable and lightweight part handling.Kolluru et al. 1417, for example, used suction-basedcontrol for handling limp material without distortion,ARTICLE IN PRESSH. Choi, M. Koc - / International Journal of Machine Tools & Manufacture 46 (2006) 135013611351deformation or damage. They developed a fixed-sizedgripper and also a reconfigurable gripper system withsuction units. A sensor-based control system based on thehierarchical control architecture controlled the operationof the robotic gripper system. Fixed dimension gripperswere developed for stacking dissimilar-sized panels ofclothes. A fuzzy controller computes the needed suctionand control depending on material porosity, weight, robotspeed, and travel distance.Rong et al. 18 presented flexible fixtures based on theuse of phase-changing materials that change the phasefrom liquid to solid upon application of electricity orelectromagnetism (known as magneto-rheologicalMRfluid). Bertetto et al. 19 made a two-degree of freedomgripper actuated by shape memory alloy (SMA) with aflexure hinge in micro scale. They designed NiTi SMAgripper and the test showed to be able to reach designperformance. The SMA has some drawback when it isapplied to high working bandwidth, because of its thermalresponse 19.2.3. Control algorithm development for grippersA basic role of the gripper is grasping an object securely.For this purpose, many researchers have investigated onconstraining algorithms. Asada et al. 20 presented formclosure grasping by a reconfigurable universal gripper.They applied the form closure concept to grasping awork-piece. They analyzed kinematic conditions for totallyconstraining an object which is assumed to be piece-wisesmooth. An efficient algorithm for examining the totalconstraint was also devised. The gripper had reconfigurablefingers consisting of a multi-degree of freedom linkmechanism. It had the capability of changing the config-uration of individual fingers so that the finger tip could belocated at an appropriate position depending on the shapeof the work-piece 20. Yoshikawa et al. 21 provided aunified theoretical framework for grasping and manipula-tion by robotic grippers and hands as well as for fixingworks by fixtures and vises. They introduced the concept ofpassive closure and active closure. Passive closure wasdivided into passive form closure and passive force closure.They studied conditions for these closures to hold an objectsecurely 21. Wallack et al. 22 developed an algorithm forplanning planar grasp configuration for the modular vise.Brown et al. 23 expanded that work to produce a 3-Dfixture and gripper design tool. They described severalanalyses, and added a 2-D algorithm, 3-D grasp qualityandgeometricloadinganalyses.Theyshowedsomeapplications and potential uses of their code in an agileassembly line 23. Qian et al. 24 presented an efficientalgorithm for computing object poses in a modular fixturegripper. They introduced efficient algorithms for com-puting poses of given objects. The computer programshowed universal application, running fast and accurateresults 24.After gripping, alignment of a part for assembly ormachining purpose is needed. Kaneto et al. 25 showed apractical procedure for achieving an enveloping grasp. Itconsists of several phases including approach, lifting,grasping and coordinate phases. The experiment alsoshowed the effectiveness of the proposed grasping proce-dure. Zhang et al. 26 showed an alignment of parts duringgrasping using a standard parallel-jaw gripper. They usedfour gripper point contacts that will align the part in thevertical plane as the jaws close. The algorithm for partalignment includes toppling, accessibility, and form-closureanalysis 26.As mentioned in the gripper design section, grippersshould be compatible with the robot and controller. Thecontrol system could vary according to its purpose,constraining algorithm, environment, and condition. Itcould be an independent and subordinate system based onthe purpose. The control system could also vary based onthe sensors and actuators that are adopted. For example,Kolluru et al. 15 used vision and optical sensors for agripper system. In their case, the gripping process iscomposed of two steps. First, the gripper is coarselypositioned by means of a vision sensor. Second, finealignment is measured and controlled using an opticalARTICLE IN PRESSFig. 1. Conceptual models of flexible gripper designs with rubber pockets, movable/adjustable jaws and additional pin locators, etc; (a) three rows ofvertical rubber pockets, (b) hemispherical rubber pockets, and (c) single rubber pocket design. In all cases, note the multiple holes and pins on the upperplate.H. Choi, M. Koc - / International Journal of Machine Tools & Manufacture 46 (2006) 135013611352sensor array. For an integrated robotic gripper system,they also suggested hierarchical control architecture andfuzzy logic formulation. For manipulating payloads withmultiple robots, Sun et al. 27 described an approach tonon-model based controls of multi-robot systems.2.4. Flexible gripping strategiesIn terms of accomplishing flexible gripping tasks, fivedifferent strategies were suggested by Pham and Yeo 1 toachieve the flexibility in a cost-effective manner. The firstkind of gripper gains its flexibility from a number ofnotches on the gripping surfaces so that objects withvarious shapes can be handled. Obviously, notching ofgripper fingers is only suitable for the parts of similar sizeand weight. Another flexible gripper concept is based oninterchangeable gripper fingers. This method is moreflexible and reliable than notching method when thegripper is equipped with a finger changing apparatus anda standard set of fingers. Another strategy is to change thegripper itself. This method can be used when a singlegripper cannot handle a whole set of parts with differentsizes, geometries and weights. These grippers need variouschanging systems for locking and unlocking grippers. Thismethodismore complexandexpensivethanotherstrategies. Finally, use of multiple grippers was alsosuggested. Multiple grippers are attached on revolving orsliding mechanisms. This technique could reduce timecomparing to gripper changing technique. But, it is obviousthat the pay load increases in proportion to the numbersof grippers. Therefore, it is more suitable for lightpayload applications such as electronics and small precisemachining.Universal grippers are also suggested to be a viableway of handling a wide range of objects with differentshapes and weight 1. The universal grippers are groupedinto two categories: active and passive grippers. Passivegrippers automatically conform to the shape of the objectsby means of gripping elements which are elastic or havepassive degrees of freedom. It was reported that, withpassive gripping, it is difficult to ensure the precise positionof the gripped object with respect to the robots coordinateARTICLE IN PRESS00.511.522.533.544.550100200300400500600700Strain (%)Stress (MPa)100% modulus1.7 MPa300% modulus2.9 MPaFig. 3. Flow stress curve of neoprene rubber material used in the FEanalyses 27.Table 1Coefficient of friction of neoprene rubber with different part materialsMaterialCoefficient of static friction on rubberWax0.5970.01Aluminum0.6670.01Steel0.6970.01Fig. 4. FE model, initial conditions (DD- Initial distance btw jaws) andmeasurement (Dy-vertical displacement of part during gripping).Fig. 2. FE models of two conceptual flexible gripper designs: (a) singlerubber pocket and (b) multiple rubber pockets.H. Choi, M. Koc - / International Journal of Machine Tools & Manufacture 46 (2006) 135013611353system. In one specific case 28, the gripper surface iscovered with a membrane comprised or cubic cells filledwith compressible fluid. The cells are separated by a flexiblebut non-elastic material. After the initial contact is made,the robot applies a force to simultaneously compress andlift the part. A shear force will be introduced by thisparticular manner of applying the force. When the liftingforce and gripping force are increased, the distortion willalso increase until the friction force is large enough to liftthe part. At this point, the distortion will reach itsmaximum. After that the distortion will decrease whenthe cells are further compressed by increasing the grippingforce because of the tendency of fluid inside the cells tomaximize its volume. The magnitude of the distortion ismonitored with shear force sensors. Thus, the point wherethe distortion decreases is the point at which it is time topick up the object. Key idea of this kind of gripper is toimitate the basics of a human hand. Although thesegrippers are so amazing and can ideally handle any kindsof part, at least in short term, active grippers are expensive,unreliable, and not a good fit for industrial use.3. Design, analysis and fabrication of a flexible gripperbased on inflatable rubber pocketsIn order to complement the efforts and realize the fullbenefitsof reconfigurableand flexible manufacturingsystems, we made an attempt to design, prototype andvalidate a flexible gripper system based on pneumaticallyinflated rubber pockets concept. In this section, design andanalysis of the flexible gripper are presented in detail.The requirements for the desired flexible gripper systemcan be summarized as follows: it should be (1) able handleparts with different shapes, sizes and weights, (2) durable,(3) highly accurate and repeatable in terms of placementpositioning (less than 100mm), (4) cost-effective, and (5)easy to implement and maintain. The targeted part sizeenvelope was 60 (w)?70 (d)?90 (h)mm, and the weightrange was between 50g (i.e., wax) and 3Kg (steel).We adopted the pneumatically inflatable rubber pocketsthat are compliant to different shapes in order to handledifferent shapes, size and weight. Fig. 1 illustrates variousconceptual designs generated based on this idea. In general,for all conceptual designs, rubber pocket(s) are embeddedARTICLE IN PRESSTable 2Factors and their levels considered in the FE analyses (Ppressure, DDinitial distance btw jaws, and Wpart weight), and response (Dy)Factors and levelsResponseInitial distancebtw jaws (DD,mm)Internal pressure(P, kPa)Weight of part(W, kg)3.0150.06Vertica