工程图尺寸标的网状文法

机械工程图尺寸标注的识别与理解是最终识别和理解机械工程图的基础。本文以国标ＧＢ４４５８－８４为基础，将尺寸标注分为２７种模式和４８种子模式，并给出了其数学描述，本文详细描述了尺寸标注的基于箭头匹配模式的网状文法。     

工程图尺寸标注识别的研究与实现

本文提出了一个识别与理解工程图尺寸标注的算法。根据国际ＧＢ４４５８－８４的规定，尺寸标注可分为２７种模式和４８种子模式。本文提出了箭头匹配的概念，总结了９种箭头匹配模式和１５种箭头匹配的前超分析模式。一个基于９种箭头匹配模式的网状文法被用于描述尺寸标注，文中给出了与之相对应的有限确定自动机ＤＦＡ及尺寸标注识别的实例。     

一种机械工程图参数化设计的新方法

通过对机械工程图的大量观察与研究，从机械工程图尺寸标注的特点出发，提出了一种新的参数化设计方法－－参数化树，并给出了一个实验例子。     

基于UG 的定型模工程图自动标注研究

针对定型模板块形状复杂不规则,内部孔特征多,尺寸标注工作量大且布局混乱等 问题,分析了定型模的结构特征,基于UG NX(Unigraphics NX)平台,开发了定型模工程图自动 标注系统。总结了定型模工程图标注需求,创建了工程图模板;基于特征提取,对定型模三维模 型自动转二维工程图时产生的冗余边线进行自动删除;基于提取的标注基准,对工程图中气孔、 水孔、定位键等特征的定位尺寸、定形尺寸进行了自动标注,并根据其位置,对工程图标注进行 合理布局。通过实例分析验证了该工程图自动标注系统的实用性。该研究简化了定型模工程图设 计流程,提高了其设计效率。     

尺寸公差模型

尺寸公差模型对产品信息的完备性和尺寸驱设计都是极为重要的。常见的尺寸公差模型是对传统工程图尺寸标注的实现，缺少设计过程方面的理论支持。文章还提出了特的特征的尺寸模式生约束模式的概念，给出了实例并讨论其应用。     

塑料异型材挤出模工程图自动标注系统研究

塑料异型材挤出模结构相对固定,但其板块工程图冗余废线较多,尺寸标注处理繁 琐。以塑料异型材挤出模为研究对象,在UG 平台上构建了塑料异型材挤出模工程图自动标注系 统,并就以下方面进行了研究：提出板块冗余废线识别方法,并采用删除与转换两种方式实现各 视图废线的自动消除;提出孔定位标注元素识别方法,并采用四象限递增排布法实现孔定位尺寸 及其公差的自动标注;提出孔特征的识别与匹配方法,实现各板块孔特征规格、公差与文字的自 动标注。通过实例分析表明该系统极大减少了图纸设计工作量,有效提高了异型材挤出模工程图 的设计效率。     

工程标注

工程标注用于标注及控制元素的大小、位置、原点等，对于二维工程图来说，它是不可缺少的一部分。本讲将集中介绍Ｓｏｌｉｄ Ｅｄｇｅ Ｏｒｉｇｉｎ为大家设计的这项功能。 一、尺寸标注工具条 如图１是尺寸标注工具条。 以下我们将逐个地介绍尺寸标注工具。 １．快捷尺寸标注 快捷尺寸标注命令可给任何单独的元素标注尺寸，但是这个尺寸标注是建立在已被选定的元素上。 例如，一个圆被选中，快捷尺寸标注可以放置半径、直径、角度和长度。如果一条直线被选中，长度和角度是可以标注，当一个元素被快捷标注选中，标注类型选项被激活。 ３当…     

工程图标注字符的提取与识别

本文介绍了一种基于连通域检测的工程图标注字符的提取与识别方法；首先建立了一种基于连通域和子连通域的工程图的层次表示，然后利用大小判据从连通域中找出字符候选，再利用共线判据提取出标注字符串，最后在预先总结出来的字符串模板的指导下，对提取出的字符串进行分析和识别。     

三维零件模型的工程图输出系统

本文在通用绘图软件AutoCADR12平台上研讨了三维零件模型的工程图表达形式，着重分析了三维零件模型的三视图、剖视图的工程表达方式以及零件尺寸的自动化标注，提出了在AutoCADR12上实现它们的原理和途径。同时，系统补充了图幅及格式的确定、局部放大、形位公差及表面粗糙度的标注等工程图表达的辅助形式，以符合实际工程的要求。     

工程图纸智能识别的分层理解模型

从工程图（机械图）的二重特性出发，分析了人脑识图的方法和特点，并模拟人脑识图过程，提出了基于知识的工程图智能识别的分层理解模型，分析了其总体结构、控制机制以及识知识的利用。     

工程图尺寸标注的识别

本文首先分析了工程图纸尺寸标注的特点及其分类，介绍了现有尺寸标注的识别方法，提出并实现了一种基于标注字符的识别算法。     

基于尺寸约束离线形成的参数化驱动方法

本文提出了实现了基于尺寸约束离线形成的参数化驱动方法，即通过对尺寸的识别理解，自动形成尺寸对图形的约束及尺寸之间的相互约束，达到尺寸约束的自动组织，从而实现参数化尺寸驱动图形。     

基于模式匹配的参数化尺寸标注机理研究

研究了一种新的参数化尺寸标注机理,提出了基于模式匹配及其推理的方法,该方法借助于ＡｕｔｏＣＡＤ的尺寸标注功能及其存储格式,将国家机械制图标准所规定的尺寸标注模式与其相匹配,在归纳ＡｕｔｏＣＡＤ和国家标准和各种尺寸标注模式的基础上,设计了一个新的参数化尺寸标注系统,实现了智能化尺寸标注功能,使其能够地标注国际所规定的各种尺寸示注模式。     

A review of machine-guarding recommendations

A series of machine-guarding drawings were developed during the 1940s, which represent the relationship between gap size and safe distance. Since the development of these drawings, larger and more comprehensive anthropometric surveys have been conducted, but they have never been compared with the drawings. The purpose of this investigation was to determine whether these original recommendations presented in the drawings are still consistent with data in the larger anthropometric surveys, especially relating to women and minorities, who are now much more prevalent in the American workplace. In this study, data from six anthropometric surveys were compared with the original machine-guarding recommendations. To minimize the percentage of the population at risk, the length dimensions were chosen from the 99th percentile male population, and thickness dimensions were chosen from the 1st percentile female population. Many of these recommendations were found to be valid, although several important modifications were suggested. Several currently recommended dimensions show no correlation to the incompressible joints utilized in this study, and it is recommended that they be eliminated. The recommendations are presented in tables of maximum gap size and minimum distance.     

Mesh-Oriented Line Drawings Theory (MOLD Theory)

In this paper, we describe a new model of bilevel digital images of line drawings. The key idea is that the constraints of generating the line drawings are available to select patterns which are considered to be a certain local appearance of line drawings. Concretely, when a bilevel digital image of line drawings is observed by 3 × 3 pixels' unit mesh, the patterns occurring in the unit mesh are restricted by the constraints that the digital image is line-structured. At first, lines in a digital image are strictly defined and then two assumptions related to the minimum line width and observing unit mesh are introduced. It is theoretically derived what kinds of patterns occur under these conditions and we call them ``legal patterns,' while the other patterns not satisfying above conditions are called ``illegal patterns.' Next, new representations such as SYM pictures and LSC pictures, which consist only of legal patterns, are proposed as a model of bilevel digital images of line drawings and the algorithms to transcribe the original bilevel digital image into the new representations in the model are introduced. Finally, the experimental results are evaluated from the viewpoint of the amount of data involved in the new representations. The results show that our theory is well-fitted to actual images and that many useful and practical applications will be derived not only in the field of documents processing, but also of digital communication.     

基于科技文档的AutoCAD 插图精准出图方法

插图中的文字高度、图线线宽和图纸比例的精准打印输出,对制图类教材或教学 课件等科技文档十分重要。为了能精确出图,在分析文字信息版面占优势的科技文档中 AutoCAD 插图制作方法的基础上,从几个绘图概念出发,研究了插图的显示特性、图形对象的 图线宽度和图中文字高度的属性特征。研究表明,只需将Word 软件所测得的插图原始尺寸看 成制作AutoCAD 图形的绘图画布和物理纸张的图幅尺寸,精准设置图形的打印出图比例、线 宽和文字高度的属性值,就能通过科技文档打印输出既精准又符合制图规范的插图。     

Automatic generation of assembly plans from topological assembly drawings

An automatic understanding system MAD-READER based on the techniques of image processing, pattern recognition, and artificial intelligence has been developed for mechanical engineering drawings. The principles of the system are presented, which include the methods and techniques of recognition and understanding for topological assembly drawings (TAD). A rule-based generator GEN-PLAN is devised to generate directly assembly plans from TAD assembly drawings. A variety of TAD assembly drawings has been used for testing the generator. So far, GEN-PLAN has been used to recognize TAD assembly drawings which consist of 31 part symbols, and generate their assembly plans. The present generator has shown favorable results.     

Some unusual primitives in the mira graphical extension of PASCAL

The MIRA system is a very general graphics system which may be useful for almost anyone interested in the production of drawings. The system allows the user to create, save, retrieve, modify and delete any kind of drawing: e.g. free-hand drawings, drawings based on geometrical primitives, algorithmic drawings, data plots, texts. Two-dimensional and three-dimensional drawings can be manipulated. The MIRA system is based on two graphical PASCAL extensions MIRA-2D and MIRA-3D. Two interactive graphical editors GRAFEDIT (two dimensions) and HORIZON (three dimensions) allow the non-specialist user to build complex drawings easily.After an overview of the MIRA system, we present the most unusual primitives, which have been developed for use with this system. These primitives can be divided into different classes: graphical types, figure algebra primitives, figure measure functions, figure recognition predicates, image transformations and animation primitives.     

尺寸标注的动态编辑与自适应处理算法

针对目前交互或参数化设计中尺寸标注存在的不足,通过对视图标注域的分区、关联尺寸的提取及自动分层,实现了删除、插入及参数修改而引起尺寸包容性变化等问题的自适应处理.