ON THE 3D PARAMETRIC MODELING OF MANUFACTURING SYSTEMS UDC: ; ; 338.3;

Transcription

1 3 rd 7 h June, year, Belgrade, Serbia. ON THE 3D PARAMETRIC MODEING OF MANUFACTURING SYSTEMS UDC: ; ; 338.3; Agahocles A. Krimpenis 1, Nikolaos A. Founas 2, George D. Noeas 3, Dimiris M. Iordanidis 4, Nikolaos M. Vaxevanidis 5 School of Pedagogical & Technological Educaion (ASPETE), Deparmen of Mechanical Engineering Technology Teachers, aboraory of Manufacuring Processes and Machine Tools (MProMaT), N. Heraklion, Ahens, GR 14121, Greece. vaxev@ah.forhne.gr Paper received: ; Paper acceped: Absrac: The presen work deals wih he parameric 3D modeling of manufacuring sysems and cells, as well as wih facory layou issues. Main focus is given on he flexibiliy of shop-floor producion, he shop-floor arrangemen and he unobsruced maerial flow hrough suiably deailed funcional-moving manufacuring sysems 3D models ha comprise of CNC machine ools, robos and conveyor bels. Parameric 3D modeling enables he rapid creaion of pars, assemblies and sysems wih an inuiive, model-cenric way. Associaion among design parameers offers flexibiliy and allows componens o be changed and updaed according o boh produc developmen and producion needs. Visualizaion of producion floor performance, maerial flow simulaion, off-line scheduling and virual machine posiioning are some of he major benefis of his concep, while a he same ime idle imes may be drasically reduced hrough off-line processes supervision. Differen layou scenarios are presened and discussed in erms of performance and efficiency. Key Words: CAD, parameric modeling, manufacuring sysems, facory layou. 1. INTRODUCTION Parameric modeling offers numerous abiliies when i comes o he design of pars and mechanisms, especially if large assemblies are involved, where manual modificaion and manipulaion of eniies is an exremely difficul and a ime-consuming process. CAD/CAM/CAE echnology in is curren sae drasically faciliaes flexibiliy of rapid produc design, engineering and manufacuring process developmen by providing a wide range of modeling eniies and engineering ools. Despie he cuing edge inegraed sofware and heir highly sophisicaed inbuil ools, vulnerabiliies appear when modificaions o large groups of componens and complex mechanisms should be performed. These issues have o be horoughly invesigaed, so as o come up wih a reliable Flexible Manufacuring Sysem (FMS) ha is able o reduce producion ime and coss, while a he same ime mainaining high qualiy of pars and producs. In [1], Savsar e al. developed a sochasic model which evaluaes performance of Flexible Manufacuring Cells (FMC) subjeced o various operaional condiions, including failures and repairs of machine ools. The main goal of heir sudy was o provide an efficien approach for rapid modificaion of echnological elemens found in indusrial faciliies. This approach incorporaes a roboic mechanism ha serves a number of machines, which he flexible manufacuring cell comprises of. Furher on, several sudies have proposed soluions and decision analysis echniques for he evaluaion of an FMS design. In [2], an analyical hierarchical process model was proposed, in order o ensure proper selecion of layou configuraions of FMS regarding boh qualiaive and quaniaive crieria. Auhors in [3] presened anoher approach owards finding improved design models ha deal wih paricular problems or updae exising modeling echniques based on mahemaical programming. This sudy uilizes a simple quadraic assignmen formulaion o minimize he overall disance among machine ools wihin manufacuring cells. In order o specify he quaniy of machines and par caegories for he design of a FMS, he closed queuing nework and he linear programming mehods were implemened o maximize profi [4]. Anoher modeling ool proposed and adoped in oher sudies is he Unified Modeling anguage (UM). UM was applied in building reusable, exendable and modifiable conrol sofware, as seen in [5] and [6]. Oher researchers have addressed he issue of designing models ha successfully manipulae and monior FMC. In [7], a review of he up-o-dae implemened manufacuring echniques in FMS is presened. Apar from FMS basics and characerisics, a manufacuring example is described, whose modeling is carried ou in a manner ha rapidly adjuss producion capaciy and funcionaliy regarding o he marke needs. Parameric modeling ofen appears in lieraure as far as coping wih curren dynamic changes of complex manufacuring sysems is concerned. Han e al [8] proposed a ool for rapid deerminaion of parameric layou during he design phase and a 3D consrucion-modeling ool during he verificaion phase. The auhors in [9] managed o handle wo major problems in he design of cellular manufacuring sysems by implemening a new muliobjecive fuzzy mahemaical model. This approach involved simulaneous handling of cell formaion process and of excepional elemens in a fuzzy environmen. Key elemens were he fuzzy parameric programming and he fuzzy model formulaion. In order for his sraegy o perform efficienly, specific 473

2 3 rd 7 h June, year, Belgrade, Serbia. mahemaical funcions mus be defined which accuraely describe manufacuring objecives and aribues, while properly evaluaing operaional procedures in manufacuring cells, also see [10]. Meng e al., [11] developed a sysem which addresses he reconfigurable layou problem of manufacuring cells design. This sysem was called Manufacuring Performance Sysem Analyser and is operaional principles were based on a previously developed sysem, known as Queuing Nework Analyser [12]. The sysem proposed in [11] is an analyical model ha is used in performance evaluaion of specific manufacuring sysems layou. Based on he parameric decomposiion mehodology, i analyically assesses he key operaional performance measures of a queuing nework. In order o enable smooh running of a sysem, a par of a daa se is uilized as he manufacuring sysem. However, assumpions have o be made concerning he geomerical properies and he machine ool configuraions, he shop floor working envelope, he manufacuring operaions assigned o machines and he effecs of scheduling sraegy. Parameric modeling of manufacuring sysems is embedded in he broader area of digial manufacuring [13]. 2. PARAMETRIC MODEING AND ARAMETERIZATION Parameerizaion is a mehod ha creaes associaions among dimensions and geomeric characerisics of pars and assemblies, in a manner ha if a parameer akes up a new value, hen a differen par or assembly is auomaically generaed [14]. Thus, parameer is a drawing variable ha relaes wih oher drawing variables hrough analyical funcions and equaions. Alhough he original parameric model akes longer o build han a normal model, all new/differen models are creaed insanly. This is a major advanage of parameric modeling, especially when a large number of similar models mus be creaed by designers or when many alernaives mus be ried ou during developmen sage of a produc. Though parameerizaion i s also possible o creae 3D CAD models for pars ha are very difficul o model oherwise, such as urbine blades and fins, due o he large number of design poins and o he complexiy of curves and surfaces. Besides, CAD models ha are creaed paramerically inherenly lead o parameric manufacuring processes, hus minimizing overall producion cos. Therefore, design parameer values used in 3D models may sem from an overall producion planning procedure, as hey affec boh produciviy and par qualiy. In he following example, parameric modeling of 3D pars is illusraed on ypical parameric CAD sofware. Through equaions, he designer can modify differen eniies and feaures of pars in erms of dimensions, such as par widh, lengh, heigh, disances beween secions, wall hickness, ec. (see Fig. 1). Parameerizaion can be performed eiher saically wih equaions or dynamically using he cursor. However, dynamic parameerizaion is no precise, because i depends on he posiion of he cursor a he mouse click. Thus, when high precision pars are modelled, he use of equaions is he only way o cope wih 3D parameric modeling. Figure 1: Examples of parameric feaures on 3D models. (a) Original par, (b) Thinner walls, (c) Thinner-higher walls, (d) Thinner-higher walls, smaller widh and smaller in-beween disance. Implemening he parameerizaion concep provides he rapid modify models and layous, hence allowing inegraion ino virual environmens, so as o es he enire work-cell in erms of funcionaliy, cooperabiliy and adapabiliy. Figure 2 depics an accurae parameric reconfiguraion of he 3D CAD model, which conains a design parameer. A new model is produced by defining large diameer D 1 and small diameer D 2. The equaion ha deermines he relaion beween he wo model diameers is D 2 = D 1 /2. The original values of he model are D 1 = 60mm and D 2 = 30 mm (see Fig. 2). The model ransformaion afer he change in D 1 value is also illusraed in Figure 2. When he value of D 1 is modified o D 1 = 40 mm, he relaed diameer D 2 is insanly modified o D 2 = 80 mm. Parameric modeling philosophy surpasses he boundaries of single par design and can easily be inroduced o major par assemblies. Thus, wih applicaion of parameric equaions, a simple model or an enire assembly of pars can be manipulaed and reconfigured by modifying jus a small se of value wih which all oher assembly dimensions are relaed. In ha sense, new alernaive models can be obained wihou re-designing he par or he assembly from scrach. 474

3 3 rd 7 h June, year, Belgrade, Serbia. Figure 2: Feaure modificaion hrough parameric equaion D 2 = D 1 / 2. (a) Original boom diameer D 1 =60 mm, (b) Original op diameer D 2 =30 mm, (c) Modified boom diameer D 1 =80 mm, (d) Modified op diameer D 2 =40 mm. 3. MACHINE MODEING AND VIRTUA CAD ENVIRONMENTS Machine design and building is an inensive endeavor, since a grea number of pars wih a high degree of deail are involved. Over he las few years, advance in CAD sofware has made 2D drawings obsolee, as large assemblies are more ambiguous and more difficul o comprehend on a wo dimensional piece of paper or on a plain 2D view on a monior screen. 3D modeling of machine ools and robos is vasly exploiable, considering ha a machine assembly can be impored in finie-elemen sofware where saic and dynamic behaviour can be analyzed, hus obaining criical poins and pars in he assembly. Wih he parameric design of machines, designers can creae highly deailed machine models and modify hem o he required dimensions. Degrees of freedom of robos are easily calculaed along wih heir moions and posiions, hus leading o opimal movemen pahs ha minimize posiioning errors and movemen imes. Tha is o say ha kinemaics simulaion on virual environmens helps in checking wheher degrees of freedom are correcly defined or pahs are consisen and carried in a ime-efficien manner. 3D parameric models can also help define seing up a new producion line as i immediaely defines he volume envelope for i according o machine ools size. Hence, i helps in making decisions regarding proper machine ool and conveyance means selecion, as well as heir opological and operaional performance in a manufacuring cell aiding in he direcion of building a flexible manufacuring cell. Furhermore, hree-dimensional models of machines can be uilized in planning a facory layou in virual environmens. This has he obvious advanage of offline posiion planning of machine ools, robos, conveyor bels and oher imporan poins in he overall manufacuring process, in order o produce assembled pars from original sock maerial. Including moion properies o he models proves very useful as i produces a dynamic analysis of a facory s operaional behavior. If no such models are available, his kind of planning should be carried ou on paper or in bes-case scenario on 2D (or pseudo-3d) planning sofware. This comes along wih a number of inheren drawbacks. Firs, he movemen space of machines is considered saic and excessively more han wha is required momenarily; his means ha alhough a a given momen a machine is a a cerain posiion, i occupies he maximum possible space in he sudy, so ha no gauging or no collision appears during operaions. However, if for example he exac posiion of a robo is known a a cerain ime window, hen anoher robo can operae inside he heoreical operaional volume of he firs one in he same ime wihou gauging. Secondly, operaion ime mus be calculaed during real-life operaions by rial and error. Machines should be posiioned according o a candidae layou and operaion imes should be measured by specialized personnel. This is a lenghy procedure ha involves high coss and effor. Wih he use of moving 3D machine models, i is possible o measure movemen and process imes hrough basic physics equaions and hen, afer concluding on he final layou and posiioning he machines, fine uning and calibraion can be achieved by measuring he differences beween model and real values. Ulimaely, process planning is grealy faciliaed wih he use of opimizaion mehodologies which can incorporae he 3D models and manage manufacuring processes in a single opimizaion algorihm. The following secions represen and describe he inen of parameric design of pars and assemblies regarding a roboic arm and a CNC 3-Axis verical machining cener. Parameer value consrains were also underaken so ha a machine's or a robo's basic srucure is mainained. 4. PARAMETRIC MODEING OF CNC MACHINE TOOS AND ROBOTS Parameric modeling enables easy and fas modificaion of assemblies dimension values, as saed previously in his paper. Indicaive examples are he parameric modeling of CNC verical milling machine ools and roboic arms. As any machine, robos, machine and cuing ools can be designed paramerically, while insering parameers wih exreme cauion, in order o avoid errors. Inroducing parameers o a 3D model is a ime consuming procedure, bu his provides users wih a fas assembly modificaion ool, since no redesign is needed for similar assemblies. 475

4 3 rd 7 h June, year, Belgrade, Serbia. Figure 3. 3D model of an indusrial ariculaed robo. 4.1 Robo parameric modelling Fig. 3 depics he model of an indusrial ariculaed robo, which is buil in a parameric manner. I is a modular assembly ha consiss of a large number of pars and complex sub-assemblies. Parameerizaion procedure is demonsraed for a cerain par of he robo s assembly (see Fig. 4). In he example, parameers D 2 o D 4 and 1 o 5 are linear combinaions of diameer D 1, which in urn is a funcion of he previous par of he robo. D 1 is called design variable of he par. If design parameer D 1 akes up a specific value, hen all oher parameer values are calculaed wih regard o he equaions in Table 1 and a new robo par is creaed. This implies ha D 1 plays he role of he driving parameer for he par depiced in Figure 4. In his example, D 1 akes values beween 150 and 300mm. Parameer value limis, are insered in appropriae ables in he CAD sofware. Figure 4. (a) 3D and (b) 2D represenaion of a roboic arm wih parameers. Table 1. Equaions for he parameric design of he robo par of Figure 4. Parameer Explanaion Equaion Diameer linked o D 1 D previous robo par 1 D 2 D 3 D Main par diameer Secondary par diameer D D 1` D2 D D Diameer linked o he nex par of he robo 4 D1 D inking lengh o 1 previous robo par Main par lengh engh of conical secion ` Secondary secion lengh inking lengh o nex 1 robo par The same exac procedure of defining correlaions among diameers and lenghs of differen pars ha he robo comprises of is carried ou hroughou he robo assembly. As far as dimensions are concerned, all robo pars are conneced o each hrough he design variables. In all, he enire robo assembly can be recreaed by he inpu of few design variables values, e.g. robo base diameer, robo oal lengh when all pars form a sraigh line, claw opening ec. Par dimensions can be consrained by ineria, for example oal assembly mass, or by oal of secondary pars needed, as screws, bols ec. 4.2 CNC milling machine ool parameric modelling CNC machine ool parameric modeling is more complex han ha of roboic arms, as presened in he previous secion. This is because consecuive pars of he robo share he same dimensions owing o geomeric coninuiy and feasible robo posiioning. Almos all pars movemens are eiher roaional or linear according o he robo s degrees of freedom and hey apply in a similar way. Machine ools, however, consis of varying pars and assemblies, each working in a differen manner and performing paricular operaions. Illusraion of parameerizaion procedure on a CNC machine ool is carried ou on a machine ool s key assembly: machine ool able and vice assembly. Fig. 5 depics he parameric drawing of he able-vice assembly. The vice is assembled on he ool able using fixuring bols and he able s T-slos. The condiions and equaions for he parameric drawing can be seen in Table

5 3 rd 7 h June, year, Belgrade, Serbia. Figure 5. 2D parameric drawings of machine ool able and vice. In order o obain a dimensioned assembly, he user needs 3 parameers: (a) shape S, which defines he ool able shape (square or recangle), (b) ool able lengh, and (c) ool able heigh h. The main difference in his parameric procedure is ha here is a parameer, namely S, which affecs ohers depending on is value. Shape parameer hus leads all dimensions of he assembly and i can seriously modify he overall shape of he CNC machine ool. Afer applying values o he design parameers, a variey of machine ool assemblies is achieved, as seen in Fig. 6, where hree differen alernaives are presened. Apparenly, he basic shape of he vice is mainained, bu is heigh is defined by ool able heigh h. Noe ha rebuilding an assembly s model mainly relies on he number of oal parameers and pars ha i comprises of. In ypical parameric CAD sofware operaing on modern compuers, his process should no ake more han few seconds even for large assemblies (more han 100 paramerically defined pars). Table 2. Equaions for he parameric design of he machine ool able and vice assembly of Figure 5. Parameer Explanaion Equaion Square, S 1 Machine ool S able XY shape X-axis larger, S 2 Y-axis larger, S 3 Machine ool able lengh Figure 6. Alernaive models of ool able-vice assembly, resuling from differen ses of parameer values: (a) b, (b) b b and (c) 4.3 Parameric modeling of manufacuring sysems A major issue when creaing manufacuring cells is he opimal placemen of machine ools and cooperaing machines. Available space for cell posiioning is limied wihin he facory walls. On he oher hand, machines should be placed in an adequae space, so ha hey can operae unobsruced by oher saic or moving producion and conveyor machines, such as benches, bels, robos ec. Building 3D CAD models for all machines involved in he manufacuring process is a useful ool in plan planning eiher he machines are already in he facory s roser or hey are going o be purchased o form a new producion cell. In case ha dimensions of he facory s sie are given, parameric machine ool models are placed in accordance wih he workspace requiremens. This happens while keeping in mind he impac of placemen on he producion process in erms of produciviy and maerial flow (see Fig. 7). b Machine ool able widh If If S 1, S b 2 b / 2 If S 3 b 2 C h v Ceners furrows C 80 2 Machine ool h able heigh h Heigh of vice h h 3 v b Figure 7. CNC machine ool placemen in given space. 477 Seing up virual manufacuring environmens is grealy faciliaed by he use of paramerically defined manufacuring unis. Simulaion of he dynamic producion process can sress ou he criical poins in he producion line, as well as he posiions where excess maerial is accumulaed or where idle imes are higher han

6 3 rd 7 h June, year, Belgrade, Serbia. expeced. Tesing alernaive cell layou scenarios is a low-cos procedure ha is performed on compuers. Afer ha, engineers can decide on he opimal layou scenario wihou in fac having he manufacuring unis moved around he plan. In his way, error and acciden possibiliies are significanly reduced. Moreover, only he necessary manufacuring unis are incorporaed in he cell, hus exploiing unis ha do no add o a specific producion philosophy in erms of delivery daes or par qualiy. Maerial can hus follow he shores possible pah so as o become a final ready-o-ship par. Using CNC machine ool models along wih appropriae CAM sofware, i is possible o define imes for all machining operaions. Robo movemen analysis offers he ime ha is needed o load and unload he machine ool. Conveyor bel velociy is also known, so he ime ha a par resides or moves on i can easily be calculaed. If he manufacuring cell is simple, such as he one depiced in Fig. 8a, a process planning sudy can be enough o maximize produciviy and reduce idle imes. However, he overall manufacuring process can sill be opimized wih appropriae algorihms, manufacuring uni placemen included. In he example of Figure 8b, machine cooperaion and workflow can be described wih he following seps: Sep 1. Conveyor bel forwards he raw par o a cerain posiion and pushes he previously compleed par o sorage. Sep 2. Roboic akes up he raw par and carries i o he CNC machine ool vice. Sep 3. Vice auomaically grips he raw par and robo moves away o safe posiion. Sep 4.Machining processes begin. Robo wais unil all machining phases are compleed. Sep 5. Robo moves owards he vice. Vice jaws open and robo picks up he compleed par. Sep 6. Robo places he compleed par o a specific posiion on he conveyor bel. Sep 7. Seps 1 o 6 are repeaed unil bach producion is complee. Figure 8. (a) Serial producion layou consising of four CNC machine ools, wo robos and hree conveyor bels in 2D simplified view, 3D downward view and 3D isomeric view; (b) A simple manufacuring cell ha comprises of a CNC milling machine, a robo and a conveyor bel in design and phoorealisic views respecively. In case ha a more complex producion line is considered, i is almos impossible o correcly manage work and maerial flow hroughou he manufacuring cell wihou proper usage of scheduling mehodologies and sofware. As menioned before, knowing he imes ha machined pars res on a cell s manufacuring uni is exremely helpful in obaining he opimal alernaive. Opimizaion algorihms, such as Geneic Algorihms, come o aid in his direcion [15]. Parameric modeling of he enire manufacuring cell involves using parameers ha define he number and alignmen of manufacuring unis wihin a consrain space. In oher words, a basic design 478 parameer of one CNC machine ool in he cell can affec he number and he size of conveyor bels or he robo size, or he overall number of manufacuring unis involved. 5. CONCUSION Owing o he use of equaions, parameric hree dimensional modeling offers significan advanages

7 3 rd 7 h June, year, Belgrade, Serbia. over he non-parameric modeling. Dimensions of pars can be insanly calculaed and heir model can be rebuil o formulae a new one in a maer of seconds by jus conrolling a small number of design parameers. Geomerical or oher echnical consrains can also be implemened o ensure ha he oucome is feasible. The aim of he presen sudy was o creae deailed parameric 3D models of CNC machine ools, robos and conveyor unis, as well o propose he formulaion of a paramerically defined manufacuring cell ha comprises of a number of manufacuring unis. The applied consrains were responsible o keep he machine models wihin physical resricions and indusrial realiy. Alhough parameric modeling usually requires more ime han ha of simple modeling of 3D pars/assemblies and careful planning of he inroduced equaions and consrains, a whole paramerically defined manufacuring cell provides manufacuring engineers wih a highly exploiable ool, which can be included in exended process planning and advanced scheduling mehodologies. Design parameers can be opimized by any Arificial Inelligence algorihm, while considering producion ime, produc qualiy, manufacuring cell flexibiliy ec. as opimizaion goals. Plan layou planning ha uilizes parameric machine models is a low cos soluion, since i is carried ou enirely on ypical modern compuers, deprived of any risks involved in real-life moving objecs and machines on he producion floor, such as machine and elecrical componen wear or damage, collisions o oher machinery or walls and personnel accidens. Suiable machine and conveyor unis placemen provides wih maximum resource usage, hus significanly increasing manufacuring processes produciviy and overall benefis. This paper is an iniial work in he field of workflow opimizaion and idle imes minimizaion in a deailed virual manufacuring environmen. However, his is no an exhausive sudy of opimal machine placemen in a manufacuring cell; his problem is currenly being sudied by he auhors and original resuls appear quie promising. I is expeced ha his approach in is final form can be robus enough o minimize design sage ime, and cos reducion while minimizing he number of rials. As an alernaive sraegy, parameric modeling can be inroduced o faciliae plans and facories in heir esablishmen of equipmen and resources. REFERENCE [1] Savsar M. and Aldaihani, M., 2008, Modeling of machine failures in a flexible manufacuring cell wih wo machines served by a robo, Reliabiliy Engineering and Sysem Safey, 93, [2] Abedi M. R., 2005, Selecion of a layou configuraion for reconfigurable manufacuring sysems using he AHP, Proceedings of 2005 Inernaional Symposium on AHP, Hawaii, July 8-10, [3] Cheng C. H. and Chen Y., 1996, Auonomous inelligen agen and is poenial applicaions, Compuers & Indusrial Engineering, 31(1-2), [4] Shin H., Park J., ee C. and Park, J., 1997, A decision suppor model for he iniial design of FMS, Compuers & Indusrial Engineering, 33 (3-4), [5] Berrue P., allican J.., Rossi A. and Philippe J.., 2005, A componen based approach for he design of FMS conrol and supervision, Proceedings of 2005 IEEE Inernaional Conference on Sysems, man and Cyberneics, Vol.4,, December , pp [6] Bruccoleri M., Diega S.N.. and Perrone G., 2003, An objec-oriened approach for flexible manufacuring conrol sysems analysis and design using he unified modeling language, Inernaional Journal of Flexible Manufacuring Sysems, 15, [7] Mehrabi M. G., Ulsoy A.G. and Koren Y, 2000, Reconfigurable manufacuring sysems: Key o fuure manufacuring, Journal of Inelligen Manufacuring, 11, [8] Kwan H. H., Bae S. M., Choi S. H., ee G. and Jeong D.M., 2011, Parameric ayou Design and Simulaion of Flexible Manufacuring Sysem, ICOSSSE '11 - Proceedings of he 10h WSEAS Inernaional Conference on Sysem Science and Simulaion in Engineering, ISBN: , pp [9] Arikan F., Gungor Z., 2009, Modeling of a manufacuring cell design problem wih fuzzy muli-objecive parameric programming, Mahemaical and Compuer Modelling, 50 (3-4), [10] Arikan F. and Gungor Z., 2005, A parameric model for cell formaion and excepional elemens' problems wih fuzzy parameers, Journal of Inelligen Manufacuring, 16, [11] Meng G., Heragu S.S. and Zijm H., 2004, Reconfigurable layou problem, Inernaional Journal of Producion Research, 42 (22), [12] Whi W., 1983, The queueing nework analyzer, The Bell Sysem Technical Journal, 62, [13] Chryssolouris G., Mavrikios D., Papakosas N., Mourzis D., Michalos G. and Georgoulias, K., Digial manufacuring: hisory, perspecives, and oulook, Proc. IMechE - Par B: J. Engineering Manufacure, 223, [14] Chang, K.-H. and Joo S.-H., 2006, Design parameerizaion and ool inegraion for CADbased mechanism opimizaion, Advances in Engineering Sofware, 37 (12), [15] Joines, J. A., 1993, Manufacuring Cell Design using Geneic Algorihms, M.Sc. Thesis, Norh Carolina Sae Universiy, Raleigh, NC, USA. 479