ISO 10303-108:2005 工业自动化系统 产品数据表示法和交换 第108部分： 综合类资源：外在几何产品用参数化法和约束条件

标准编号：ISO 10303-108:2005

中文名称：工业自动化系统 产品数据表示法和交换 第108部分： 综合类资源：外在几何产品用参数化法和约束条件

英文名称：Industrial automation systems and integration — Product data representation and exchange — Part 108: Integrated application resource: Parameterization and constraints for explicit geometric product mo

发布日期：2005-02

标准范围

ISO 10303-108:2005规定了用于在CAD或其他类型的模型中表示模型参数和约束的资源结构，以及将它们与传输模型的几何或其他元素相关联所需的机制。这些能力的使用潜在地允许模型在其起源系统中的行为的某些方面与基本模型本身一起被传达。传输该附加信息的意图是向接收系统提供数据，该数据将使其能够在传输之后重建模型中的相应行为特征。理想情况下，这将使模型能够在接收系统中编辑，就像它是在那里创建的一样。如果没有所谓的设计意图信息的交换，这是不可能的。ISO 10303-108:2005能够捕捉和传递设计意图的一个重要方面。以下内容属于ISO 10303-108:2005的范围:通过变量与其中出现的量（包括尺寸值）的关联来参数化模型；定义可变参数之间的数学关系的约束；对模型的约束，表示为其组成元素或这些元素的属性之间的描述性关系；与产品形状建模中常用的几何约束相对应的专用描述性约束（例如，几何元素之间的平行或相切）；参数化和约束在二维和三维形状模型中的应用；二维几何草图或轮廓的专用表示；不完全定义的模型的表示，即模型中的某些值可能被视为未完全约束。以下内容超出了ISO 10303-108:2005的范围:程序或基于历史的模型表示，以构造操作的顺序表示；隐含的或程序定义的约束，在构造操作的操作中固有的；约束方程组的求解方法；形状模型的形状特征；在转移之后编辑变分模型的系统的行为；约束满足中的准确性考虑。以下注意事项适用于排除的功能。基于程序或历史的表示是ISO 10303-55的主题。求解约束方程的方法是交换中涉及的应用系统的责任。ISO 10303-108:2005仅传递需要解决的约束关系。ISO 10303的各种其他部分提供了表单特征的不同面向应用程序的视图的表示。通过使用ISO 10303-108:2005传输的信息旨在允许实施者在上述情况下通过在模型传输之后接收系统来提供“合理的”或“直观的”行为，但是ISO 10303-108:2005没有规定这种行为或其向系统用户的呈现的详细性质。在ISO 10303-108:2005的背景下，准确性考虑与通常在产品形状的几何建模中出现的考虑基本相同。在ISO 10303的其他地方提供了用于解决准确度问题的方法。

ISO 10303-108:2005 specifies the resource constructs for the representation of model parameters and constraints in CAD or other kinds of models, together with the mechanisms necessary for associating them with geometric or other elements of transferred models. The use of these capabilities potentially allows certain aspects of the behaviour of a model in its originating system to be conveyed together with the basic model itself. The intention in transferring this additional information is to provide the receiving system with data that will enable it to reconstruct corresponding behavioural characteristics in the model following the transfer. Ideally, this will enable the model to be edited in the receiving system just as as though it had been created there. That would not be possible without the exchange of what is known as design intent information. ISO 10303-108:2005 enables the capture and transfer of an important aspect of design intent.The following are within the scope of ISO 10303-108:2005:

• parameterization of models through the association of variables with quantities occurring in them, including dimensional values;
• constraints defining mathematical relationships between variable parameters;
• constraints on models expressed as descriptive relationships between their constituent elements or attributes of those elements;
• specialized descriptive constraints corresponding to the geometric constraints commonly used in product shape modelling (e.g., parallelism or tangency between geometric elements);
• applications of parameterization and constraints to two- and three-dimensional shape models;
• specialized representations for two-dimensional geometric sketches or profiles;
• representation of models that are incompletely defined in the sense that certain values in the model may be regarded as not fully constrained.

The following are outside the scope of ISO 10303-108:2005:

• procedural or history-based model representations, expressed in terms of sequences of constructional operations;
• implicit or procedurally defined constraints, inherent in the operation of constructional operations;
• solution methods for systems of constraint equations;
• form features of shape models;
• behaviour of a system in which a variational model is edited following a transfer;
• considerations of accuracy in constraint satisfaction.

The following notes apply to the excluded capabilities.

1. Procedural or history-based representations are the subject of ISO 10303-55.
2. Methods of solving constraint equations are the responsibility of the application systems involved in the exchange. ISO 10303-108:2005 merely transfers the constraint relationships that need to be solved.
3. Various other parts of ISO 10303 provide representations for different application-oriented views of form features.
4. The information transmitted by the use of ISO 10303-108:2005 is intended to allow implementers to provide 'reasonable' or 'intuitive' behaviour by receiving systems following the transfer of a model in the circumstances mentioned above, but ISO 10303-108:2005 does not prescribe the detailed nature of such behaviour or of its presentation to the system user.
5. Accuracy considerations are essentially the same in the ISO 10303-108:2005 context as those arising generally in the geometric modelling of product shape. Means are provided elsewhere in ISO 10303 for addressing accuracy issues.

标准预览图