1、 Reference number ISO 10303-55:2005(E) ISO 2005INTERNATIONAL STANDARD ISO 10303-55 First edition 2005-02-01 Industrial automation systems Product data representation and exchange Part 55: Integrated generic resource: Procedural and hybrid representation Systmes dautomatisation industrielle Reprsenta
2、tion et change de donnes de produits Partie 55: Ressources gnriques intgres Reprsentation procdurale et hybride ISO 10303-55:2005(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobes licensing policy, this file may be printed or viewed but shall not be edited unl
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7、ished in Switzerland ii ISO 2005 All rights reservedISO10303-55:2005(E) ContentsPage 1 Scope . 1 2 Normative references . . . 2 3 Terms, denitions and abbreviations . 2 3.1 Terms dened in ISO 10303-1 2 3.2 Terms dened in ISO 10303-11 . . . 3 3.3 Terms dened in ISO 10303-42 . . . 3 3.4 Terms dened in
8、 ISO 10303-43 . . . 3 3.5 Terms dened in ISO 10303-108 . . . 4 3.6 Other terms and denitions 5 3.7 Abbreviations . . . 5 4 Procedural model . 6 4.1 Introduction . . . . 6 4.2 Fundamental concepts and assumptions . 6 4.2.1 Procedural models . 7 4.2.2 Hybrid models . . . 8 4.2.3 Explicit selected elem
9、ents . . . 8 4.2.4 Dual models 9 4.2.5 Representation of constructional operations in procedural models 1 0 4.2.6 Implicit and explicit constraints 1 1 4.2.7 Suppression of constructional operations . 1 2 4.2.8 Exchange of procedural and hybrid models 1 2 4.2.9 Variational cases of procedural and hy
10、brid models . . 1 2 4.3 Procedural model entity denitions . 1 3 4.3.1 explicit procedural representation relationship . . . . 1 3 4.3.2 explicit procedural representation item relationship . 1 4 4.3.3 procedural representation . . . 1 5 4.3.4 procedural representation sequence . . . . 1 6 4.3.5 user
11、 selected elements . 1 7 4.3.6 indirectly selected elements . . 1 8 5 Procedural shape model . . 2 0 5.1 Introduction . . . . 2 0 5.2 Fundamental concepts and assumptions . 2 0 5.2.1 Procedural shape models 2 1 5.2.2 Hybrid shape models 2 2 5.2.3 Explicit selected elements in a shape model 2 2 5.2.4
12、 Dual shape representations . . . 2 2 5.2.5 Design rationale for shape models . 2 2 5.3 Procedural shape model type denitions . 2 3 5.3.1 shape representation item . . . 2 3 5.4 Procedural shape model entity denitions . . . . 2 3 5.4.1 explicit procedural shape representation relationship. 2 3 5.4.2
13、 explicit procedural geometric representation item relationship . 2 4 5.4.3 procedural shape representation 2 5 5.4.4 procedural shape representation sequence 2 5 5.4.5 procedural solid representation sequence . 2 6 c ISO2005AllrightsreservediiiISO10303-55:2005(E) 5.4.6 procedural surface representa
14、tion sequence 2 7 5.4.7 procedural wireframe representation sequence . . . . 2 8 5.4.8 user selected shape elements . 2 8 5.4.9 indirectly selected shape elements . . . . 2 9 Annex A (normative) Short names of entities 3 1 Annex B (normative) Information object registration . 3 2 B.1 Document identi
15、cation . 3 2 B.2 Schema identication . . . 3 2 B.2.1 procedural model schema identication . . 3 2 B.2.2 procedural shape model schema identication . . . . 3 2 Annex C (informative) Computer interpretable listings . 3 3 Annex D (informative) EXPRESS-G diagrams . 3 4 Annex E (informative) Examples of
16、the use of this part of ISO 10303 . 3 8 E.1 Example of non-geometric application of procedural modelling . . . . 3 8 E.2 Example of intended usage of the procedural shape model schema . 3 8 E.3 Example of the use of variational (parameterization and constraint) information with a procedural model .
17、4 0 E.4 Example of the embedding of operation sequences and the recording of design rationale 45 Bibliography . . . 4 7 Index . 4 8 Figures Figure 1 Schema level diagram of relationships among ISO 10303-55 schemas (inside the box) and other resource schemas . viii Figure D.1 procedural model schema
18、EXPRESS-G diagram 1 of 1 3 5 Figure D.2 procedural shape model schema EXPRESS-G diagram 1 of 2 . . . 3 6 Figure D.3 procedural shape model schema EXPRESS-G diagram 2 of 2 . . . 3 7 Figure E.1 Relationships between instances of procedural, variational and explicit models for the cases of (a) no varia
19、tional model, (b) no procedural model, and (c) all three models. . . 42 Table A.1 Short names of entities . . . 3 1 ivc ISO2005AllrightsreservedISO10303-55:2005(E) Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bod
20、ies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical com- mittee has been established has the right to be represented on that committee. International organizations, governmental a
21、nd non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical stan- dardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directiv
22、es, Part 2. The main task of technical committees is to prepare International Standards. Draft International Stan- dards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75% of the member bodies
23、 casting a vote. Attention is drawn to the possibility that some of the elements of this part of ISO 10303 may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO10303-55waspreparedbyTechnicalCommitteeISO/TC 184/SC 4,Industrialautomat
24、ionsystems andintegration,SubcommitteeSC 4,Industrialdata. ISO 10303 consists of a series of parts, under the general title Industrial automation systems and integration Product data representation and exchange. The structure of ISO 10303 is described in ISO 10303-1. Each part of ISO 10303 is a memb
25、er of one of the following series: description methods, implementation methods, conformance testing methodology and framework, integrated generic resources, integrated application resources, application protocols, abstract test suites, application interpreted constructs, and application modules. Thi
26、s part is a member of the integrated generic resources series. The integrated generic resources and the integrated application resources specify a single conceptual product data model. A complete list of parts of ISO 10303 is available from the Internet:Should further parts of ISO 10303 be published
27、, they will follow the same numbering pattern. c ISO2005AllrightsreservedvISO10303-55:2005(E) Introduction ISO 10303 is an International Standard for the computer-interpretable representation of product infor- mation and for the exchange of product data. The objective is to provide a neutral mechani
28、sm capable of describing products throughout their life cycle. This mechanism is suitable not only for neutral le ex- change, but also as a basis for implementing and sharing product databases, and as a basis for archiving. This part of ISO 10303 is a member of the integrated resources series. Major
29、 subdivisions of this part of ISO 10303 are: Procedural model schema; Procedural shape model schema. This part of ISO 10303 provides general mechanisms for the representation of models dened in terms of the operations used to construct them. The constructional operations themselves are represented b
30、y entity data types dened in other parts of ISO 10303, interpreted as constructors. Procedural models have the advantage of being easy to edit, simply by changing values of parameters used as arguments of their constructional operations. Such models are said to embody design intent information, in t
31、he sense that modications to them conform to the scheme of parameterization imposed by their original creator, and also comply with any constraints implied by the particular constructional operations used. Thus the transfer of a procedural model into a receiving system carries with it information as
32、 to how the model will behave when edited following the transfer. However, procedural models also have the disadvantage of containing (in their purest form) little or no explicit information about the result of actually performing the sequence of operations. This fact makes them unsuitable as a basi
33、s for the automation of many engineering processes that depend on the use of explicit geometric information, for example numerically controlled machining or inspection. Systems for engineering purposes commonly achieve the advantages of both modelling approaches through the use of a dual representat
34、ion, comprising a primary representation of the procedural or con- struction history type together with a secondary explicit representation. Other ISO 10303 resources pro- vide the elements needed for explicit representions. This part of the standard not only species resources for procedural represe
35、ntations but also provides a dual model capability by enabling the association of such a model with its corresponding explicit counterpart. The initial focus of this part of ISO 10303 was to allow the capture and exchange of CAD shape rep- resentations of the procedural and hybrid types (a hybrid re
36、presentation is basically procedural but also contains some explicit elements). However, the capabilities provided also have general applicability for the transfer of any type of procedurally represented or hybrid model, whether geometric or non- geometric. In the case of shape models, ISO 10303-42
37、is the primary resource for the corresponding explicit representations. Because procedural representations are inherently parametric, they can be edited by changing the values of input arguments of constructional procedures. However, this requires that the system operator has an appropriate level of
38、 understanding of the rationale underlying the original constructional method. At the time of writing, no method is known for capturing design rationale information automatically during model construction, and provision is therefore made in this part of ISO 10303 for its representation as descriptiv
39、e text, assumed to be supplied by the original designer. It is useful to emphasize the distinction between design intent and design rationale. Design intent is cap- vic ISO2005Allrightsreserved tured in the schemes of parameterization and constraints imposed upon models during their construction.ISO
40、10303-55:2005(E) It therefore governs the ways in which a model may be edited. Design rationale, on the other hand, is concerned with the reasons why a particular conguration or constructional process was adopted, and therefore with the logic underlying the design intent. The industry motivation for
41、 the exchange of procedural, hybrid and dual representations arises from the difculties that have been encountered in the editing of ISO 10303 explicit models in a receiving system, following a model transfer. If only an explicit model is transferred, as in the past, the design intent embodied in th
42、e procedural component of the dual model in the sending system is lost in the transfer. The consequences are that received model is incomplete in vital respects, and that editing it is difcult or impossible. Three books and a conference paper providing further background on the topics covered by thi
43、s part of ISO 10303 are given in the Bibliography 6 9. The contents of the two schemas making up this part of ISO 10303 are as follows: procedural model schema: Fundamental mechanisms for the representation of procedural and hybrid models, and for the capture of design rationale. procedural shape mo
44、del schema: Specialization of the foregoing schema for the specic case of geometric models. The relationships of the schemas in this part of ISO 10303 to other schemas that dene the integrated resources of ISO 10303 are illustrated in Figure 1 using the EXPRESS-G notation. EXPRESS-G is dened in anne
45、x D of ISO 10303-11. The schemas occurring in Figure 1 are components of ISO 10303 integrated resources, and they are specied in the following resource parts: product property representationschema ISO 10303-41 support resource schema ISO 10303-41 geometric model schema ISO 10303-42 geometry schema I
46、SO 10303-42 topology schema ISO 10303-42 representationschema ISO 10303-43 variational representationschema ISO 10303-108 NOTE 1 A procedural model is a representation of a constructional process, and it may therefore be envisaged that ISO 10303-49 (Process structure and properties) 1 would be a sui
47、table underlying resource for this part of ISO 10303. However, the denition of process as given in ISO 10303-49 is a narrow one: process: a particular procedure for doing something involving one or more steps or operations. The process may produce a product, a property of a product, or an aspect of
48、a product. Thus the ISO 10303-49 view of a process is one that is concerned with the generation of a physical object or some characteristic of it. The purpose of this part of ISO 10303, by contrast, is to provide the means for capturing and transferring constructional processes for representations o
49、r models of general objects, which only exist as abstractions in a computer or database. For this reason, and also because advantage can be taken of the very close relationship between procedural modelling operations and existing entities dened in other ISO 10303 integrated resources, ISO 10303-49 has not been used as the basis for the present part of ISO 10303. NOTE 2 In the diagram on the following page, the schemas occurring in this part of ISO 10303 are enclosed in a heavy rectangular box. The spec
