ComputerAided_Design_Engineering_amp_Manufactur.pdf

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Note that there are two transitions, t7 and t8, in , we can pick either one as the of the new TPpath. The tool conveys this information to the designer by popping up a new window, inside which is displayed an arrow linking two sets of transitions: {t7, t8} and—(an empty set). Picking t7 results in the dotted lines in Figure 8.12(c). The tool then pops up another window linking two empty sets and signaling the completion of this step of synthesis. The set of home places now is H � {p1, p8}. Machines 1, 2, 3, and R2 are required to start their corresponding operations. Thus, using Rules TT.2 and TT.4, generate the new paths: [t3 p12 t2], [t8 p9 t7], [t5 p11 t4], and [t6 p10 t5] (Figure 8.12(d)) where p12, p9, p11, and p10 model the availability of M1, M2, R2, and M3, respectively. Considering the AGV1, first generate a TT-path between t4 (in � � [p4 t4]) and t3 (in �� [t3 p4]), i.e., [t4 p13 t3]. Then add a token to p13 using Rule TT.2. Since LEX([p4 t4], [t3 p4]) � �, add nothing, according to Rule TT.4. LEX([t3 p4], [p4 t4]) can be any one of {[t8 p8]}, {[t7 p7 t8]}, and {[p1 t6]}. Using either {[t8 p4} or {[t7 p7 t8]}, add the virtual PT-path from p13 to t8 as the dotted line in Figure 8.12(d). This implies that once Machine 2 completes its processing, AGV1 delivers the part. Theoretically, one may use {[p2 t7]} and then a PT-path [p13 t7] would be added. H � {p1, p8–p13}. Having synthesized the partial system, i.e., the production portion from Enry 1 to Exit 1, now synthesize the rest of the portion, from Entry 2 to Exit 2, to involve Machines 4 and 5, AGV2, and Robots 1 and 2. For [t7 p8 t1] and [t5 p11 t4], applying Rule PP.1 leads to the two cycles [p8 t9 p14 t10 p8] and [p11 t11 p15 t12 p11]. The meanings of the added places are shown in Figure 12(e). Consider two new PSPs: �4 � [p8 t9 p14 t10 p8] and �5 � [p11 t11 p15 t12 p11] and choose t10 from �4 and t11 from �5 to generate a new PSP, psp � [t10 p16 t13 p17 t11]. Note each of the transitions, t10 and t11, is in a cycle that was generated using Rule PP.1. Hence, now apply Rule TT.3 to pick up t9 from �4 and t12 from �5 and generate psp’ � [t12 p18 t14 p19 t9]. It is easily verified that psp, psp,’ �4 , and �5 constitute a cycle. Furthermore, insert the tokens in p19 to represent the availability of raw material from Entry 1 to fulfill Rule TT.2. H � {p1, p8–p13, p19}. Now apply Rule TT.2 to obtain the paths: [t13 p20 t10], [t11 p21 t13], and [t14 p22 t12], which model the availability of Machines 4, 5, and AGV2. H � {p1, p8–p13, p19–p22}. This completes the modeling process and the final net is depicted in Figure 8.11 as a bounded, live, and reversible net if �p � H, M0 (p) � 0 and �p � PN-H, (p) � 0; i.e., the places in the net have no tokens, except those in H. 8.7 Enhancement of Synthesis Rules The synthesized nets, however, are limited in classes because some generations are prohibited. Recently the author 34 has discovered new synthesis rules such that path generations previously forbidden are now allowed without incurring logical incorrectness. For instance, a TT-path generation (e.g., PSP [t3 p4 t4] in Figure 8.13(a)) between two exclusive transitions was forbidden (Rule TT.0); the new rule is that it is acceptable with additional path generations (PSP [t4 p5 t3]) such that the two exclusive transitions (t3 and t4) become synchronized and hence sequential to each other. As a result, more classes of nets can be synthesized. Another ex<strong>amp</strong>le is shown in Figure 8.14, 27 which models a machine/assembly shop with resource sharing and cannot be synthesized unless we allow TT-path generations between exclusive transitions and extend the rules to GPNs. In the sequel, we explain the model and develop the rules for both. The Model M 0 � 3 The net model consists of three parts: Components I and II and the interconnecting part between them. The system assembles two Type-1 parts and three Type-2 parts into a final product. Type-1 and Type-2 parts are processed in Workstations 1 and 2, respectively, from the corresponding raw stocks fed by Conveyors 1 and 2, respectively. Robot 1 (3) loads Type-1 (2) raw stock from Conveyor 1 (2) into Workstation 1 (2), performs some machining, and loads the finished part into the buffer. The above two subactivities are modeled by Components I and II, respectively. Component II also models the assembly process in t g
FIGURE 8.13 An ex<strong>amp</strong>le of rule TT.0. (a) [t3 p4 t4] is generated. The net deadlocks or is unbounded. (b) The addition of [t4 p5 t3] renders the net live and bounded. Workstation 2. After the three Type-2 parts finish machining, they are assembled (along with the two Type- 1 parts loaded by Robot 2 from the buffer in Component I) on the same Workstation 2 by Robot 3. After the assembly task is completed, the final product is placed on Conveyor 3 by Robot 3. The interconnecting part between Components I and II models the loading process of two Type-1 parts by Robot 2 from the buffer to Workstation 2. To further understand the model, Table 8.4 lists the physical meaning of key transitions and places in Figure 8.14 where “WS” denotes a workstation, “R” a robot, and “C” a conveyor. This net contains multiple-weighted arcs and hence cannot be synthesized using the current rules. We will extend the rules by including the synchronization rule for TT-path generations among exclusive PSPs and the arc-ratio rule for handling GPNs. The Synchronization Rule Here, we develop new Rule TT.4 for exclusive TT generations. We first define the following terms for the description of the synchronization rule: p d Definition: A decision place is the common generation place of a set of exclusive PSPs.
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COMPUTER-AIDED DESIGN, ENGINEERING,
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Library of Congress Cataloging-in-P
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Editor Cornelius T. Leondes, B.S.,
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Chapter 1 Chapter 2 Chapter 3 Chapt
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the implementation of the IPD syste
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In our IPD system implementations,
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2. Specification of analysis-specif
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FIGURE 1.2 base or the design insta
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FIGURE 1.4 System architecture of t
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of a beam is considered for FEA. Th
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FIGURE 1.7 through the control expe
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2. machining facility (e.g., gang m
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from the FBDS. The user also specif
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Depending on the type of feature to
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TABLE 1.6 Tolerance synthesis is de
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FIGURE 1.12 Display of the NC tool
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component geometric entities and va
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FIGURE 1.14 The system architecture
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TABLE 1.10 User Input for the Toler
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TABLE 1.11 Tolerance Specifications
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7. Z. Young and I. R. Groose. A rul
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FIGURE 2.1 Tool paths generated for
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FIGURE 2.2 sented by instances of f
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TABLE 2.1 A CAD-Generated Hole Conf
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FIGURE 2.6 mounted on the rotary ta
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FIGURE 2.8 fixture for the machinin
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FIGURE 2.10 or best-fit, or the cur
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FIGURE 2.11 Linear approximation of
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FIGURE 2.13 Circular approximation
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FIGURE 2.14(b) Circular approximati
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FIGURE 2.16 Types of biarcs. FIGURE
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FIGURE 2.18 Approximation of scanne
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FIGURE 2.20 A touch trigger probe c
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TABLE 2.4 Substitute Elements in CM
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FIGURE 2.21 CMM planning requiremen
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Product Model Representation for Co
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© 2001 by CRC Press LLC TABLE 2.5
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TABLE 2.7 Partial Listing of Dimens
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24. Makinouchi, S., Okamoto, M., an
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Bijan Shirinzadeh Monash University
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FIGURE 3.1 Trends in flexible manuf
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FIGURE 3.3 and constrain different
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Other Fixturing Techniques There ar
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FIGURE 3.6 contact point. The geome
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FIGURE 3.8 The vertical support fix
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and moments about the contact point
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een identified, the normals are use
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one of choosing the variables: such
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Fixture Module Location An importan
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FIGURE 3.15 Illustration of functio
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FIGURE 3.18 Minimum separation test
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direction) the face, respectively.
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FIGURE 3.21 Software structure for
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3.8 Conclusion A reconfigurable fix
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Heui Jae Pahk Seoul National Univer
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FIGURE 4.1(b) Conceptual framework
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4.3 Measurement Points Sampling and
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Surface S2 Measurement Path FIGURE
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FIGURE 4.4 Rough phase alignment ba
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deviation between the nominal CAD d
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FIGURE 4.6(a) Sum of squares distan
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FIGURE 4.7(c) Trailing edge. (c) th
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FIGURE 4.8(a) Profile tolerance of
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The calculated minimum form error i
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FIGURE 4.11(a) A typical mold havin
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FIGURE 4.11(d) Inspection results f
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FIGURE 4.12(c) Maximum deviation (p
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5.1 Introduction Developments in th
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process plan for a part (Figure 5.3
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FIGURE 5.5 leading to the developme
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the previously stored process plan
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FIGURE 5.7 Techniques of defining a
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Feature Recognition and Extraction
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in relation to another feature (e.g
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FIGURE 5.9 Framework for building a
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FIGURE 5.10 Process plan content.
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FIGURE 5.12 Schematic sketch of the
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Several techniques of defining a fe
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TABLE 5.1 Data Structure for Repres
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FIGURE 5.16 Classification of the t
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system to ensure that the part bein
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FIGURE 5.19 Graphical model of the
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TABLE 5.4 Data Structure for Repres
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FIGURE 5.20 Mapping between machini
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algorithms. (Some details of the pr
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FIGURE 5.24 An example rotational p
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FIGURE 5.26 Down_face-turn-up_face
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FIGURE 5.27 Procedure for machine t
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FIGURE 5.28 Determining the number
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DL is needed to be set only if the
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FIGURE 5.31 Operation sequencing co
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Cutting Tool Selection Selection of
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1. A tool is searched for in the da
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FIGURE 5.32 Inputs to optimization
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When these values are substituted,
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Usually, maximum and minimum speed
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FIGURE 5.33 Solution methodology.
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TABLE 5.6 Process Plan Internal Rep
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In a strict theoretical perspective
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18. Domazet, D. S. and Lu, S. C. Y,
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63. Prasad, A. V. S. R. K., Rao, P.
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CAD systems. The sample consists of
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learn to master the new system. An
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Although researchers appear to agre
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Link and Zmud28 found that organic
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Informal Training Informal CAD trai
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informal training programs, felt th
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6. C. A. Beatty, Tall Tales and Rea
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A.Y.C. Nee National University of S
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FIGURE 7.1 Planning, design, and ma
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A metal stamping can have the follo
Page 223 and 224: FIGURE 7.3 Strips used to notch out
Page 225 and 226: A Skeletal Approach for the Recogni
Page 227 and 228: These findings can be used to devel
Page 229 and 230: Semi-Direct Piloting In cases where
Page 231 and 232: a larger value, the die operations
Page 233 and 234: FIGURE 7.9 Symbolic relationship be
Page 235 and 236: FIGURE 7.11 The shape of the envelo
Page 237 and 238: TABLE 7.1 Schema for the Generation
Page 239 and 240: strong reasons to support a move to
Page 241 and 242: FIGURE 7.16 3-D CAD model of a part
Page 243 and 244: References Cheok, B.T. et al. (1994
Page 245 and 246: include the once forbidden generati
Page 247 and 248: A temporal matrix (T-Matrix) is pro
Page 249 and 250: FIGURE 8.1 A basic process. (From R
Page 251 and 252: FIGURE 8.4(a) Generate a new IG usi
Page 253 and 254: Note if the pair of nodes are both
Page 255 and 256: TABLE 8.1 Summary of the Rules Cond
Page 257 and 258: The correctness of these rules is e
Page 259 and 260: needs to show that after each full
Page 261 and 262: ule is violated, a warning should b
Page 263 and 264: Π1 Π3 Π4 FIGURE 8.8(a) After add
Page 265 and 266: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Page 267 and 268: A ik � ‘U’ and is in a cycle
Page 269 and 270: FIGURE 8.12(a) Add [p2 t7 p7 t8 p4]
Page 271 and 272: FIGURE 8.12(c) Add a token to p8 vi
Page 273: FIGURE 8.12(e) Add [p8 t9 p14 t10 p
Page 277 and 278: FIGURE 8.14 A GPN model of a machin
Page 279 and 280: FIGURE 8.15(b) The first exclusive
Page 281 and 282: FIGURE 8.15(d) The last exclusive T
Page 283 and 284: FIGURE 8.15(f) After entering the a
Page 285 and 286: FIGURE 8.15(h) Completion of Compon
Page 287 and 288: FIGURE 8.15(j) Two PP-generations:
Page 289 and 290: FIGURE 8.15(l) The last exclusive T
Page 291 and 292: t1 t5 p1 p5 t6 (a) t2 t3 t4 2 2 p2
Page 293 and 294: FIGURE 8.17 An example of partial f
Page 295 and 296: Theorem 10: If pi → pk in a synth
Page 297 and 298: Note that control transitions are o
Page 299 and 300: t j than the lower at , it indicate
Page 301 and 302: • Programming logic and VLSI arra
Page 303 and 304: 7. Chao, D. Y. and D. T. Wang, Appl
Page 305 and 306: 53. Villaroel, J. L., J. Martinez,
Page 307 and 308: q u : the numerator of the least ra
Page 309 and 310: geometric modeling, engineering ana
Page 311 and 312: In dimension driven or parametric d
Page 313 and 314: FIGURE 9.3 configuration of bodies
Page 315 and 316: FIGURE 9.6 FIGURE 9.7 Geometric Int
Page 317 and 318: FIGURE 9.8 Intersection of degrees
Page 319 and 320: will introduce a way to propagate p
Page 321 and 322: Completeness of Dimensions Complete
Page 323 and 324: FIGURE 9.12 3-D constraints. © 200
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The distance constraint from pt �
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therefore: Now merge the lists and
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Quantity analysis methods have the
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y a revolute joint. By selecting al
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