ED-DESIGN: An engineering drawing based design model for computer understanding

Constructing a solid model through computer understanding of engineering drawings could resolve the input problem of solid models. For computer understanding, however, the engineering drawing has to be defined and represented with clear semantics. The conventional engineering drawing is usually described by showing examples and represented as a set of curve segments on a drawing plane, so that it can only be understood by human engineers. In this paper, an engineering drawing based design model, ED-DESIGN, which is much more computer understandable than the conventional one is proposed. In this model, an engineering drawing is represented in a drawing space rather than in a drawing plane. In other words, the scheme of engineering drawing is interpreted as pseudo-3D surface design scheme rather than a 2D design scheme. With this design model, it is possible to develop definite knowledge for constructing a solid model through computer understanding.     

Solidworks在铸造模型设计制造过程中的应用

长期以来,铸造用模的制造一直沿袭着零件图→铸造工艺图→模块设计放样→制造组合这一程序,制造周期长,成为新产品开发的瓶颈。我们应用计算机三维软件Solidworks将产品图纸转化为电子图形,然后结合铸造工艺参数直接编辑修正成放样图,实现了产品设计与模型制造交叉作业、相互验证,大大加快了模型制造的进度,提高了模型质量。     

尺规作图CAI课件的设计及实现

尺规作图是现行初中几何课程中一段实践性较强的内容,文 中探讨了尺规作图在计算机上的实现。以尺规作图中具有代表性的一个模块——“作一个角 等于已知角”为例,介绍尺规作图课件的设计和实现,充分利用了动画技术实现尺、规移动 ,两点连线,点、线或弧闪烁,再现了圆规画弧这一制作的关键。     

二维绘图中的自动消隐算法

该文以装配图为例,对二维绘图中的自动消隐问题提出并实现了一种有效算法。对该算法中的零件图边界构造、下层图素与零件图边界的交点计算、根据求得的交点对图素进行分割消隐等问题,文章进行了深入具体的讨论。     

基于MFC的DirectDraw高速图形绘制方法与应用

在工业控制环境下采用GDI内存作图方式可以加速图形绘制,但对复杂图形的高速绘制效果并不理想.提出以MFC编程来实现基于DirectDraw实时图形绘制方法,能产生快速、平稳的复杂图形,并且通过一个复杂图形绘制的实例,详细讨论了的步骤.     

CAD在机械制图中的应用探讨

机械制图是用图样绘制机械的形状等参数,是设计者和制造者进行交流的工程界语言。在Auto CAD引入之前,机械制图还是纯手工制图,制作过程比较耗时,修改较为困难。引入了Auto CAD之后,取代了纯手工制图,完全采用数字化制图,大大提高了工业制图的效率,项目和项目之间的制图可以复用,缩短了项目产品的开发周期,是一个机械制造企业重要的参考指标。本文主要介绍Auto CAD应用到机械制图中的优势,并具体介绍Auto CAD应用到机械制图中的技巧。     

Multi-objective optimization of an auto panel drawing die face design by mesh morphing

In order to facilitate the tryout or simulation process at the end of a manual auto panel drawing die face design process, we use finite element analysis (FEA) and a multi-objective genetic algorithm (MOGA) to find all the Pareto optimal solutions in one go and to achieve the optimal design of an auto panel drawing die face instead of transforming multi-objective functions into a single objective function, and employ a novel mesh morphing technique to achieve fast modification of parametric or non-parametric addendum surfaces and binder surfaces on drawing die faces without going back to CAD for reconstruction of geometric models or to FEA for remodeling. We use an auto panel drawing die face design process as an example to illustrate the application and effectiveness of this proposed approach, and come to the conclusion that the proposed approach is more effective than the traditional manual FEA method and the ‘trial-and-error’ approach in optimizing an auto panel drawing die face design.     

建筑结构图版面分析方法研究

工程图的计算机识别和理解技术是计算机应用于工程方面的研究热点之一,图形的版面分析是图形理解的基础。文章给出了基于图形和基于图像的两种版面分析和划分算法,并对两种方法在速度、效果方面进行了比较。实验证明,基于图像的版面分析和划分算法在线条数较多时优于基于图形方法的结论。     

Overcoming superstrictness in line drawing interpretation

Presents an algorithm for correcting incorrect line drawings-incorrect projections of a polyhedral scene. Such incorrect drawings arise, e.g., when an image of a polyhedral world is taken, the edges and vertices are extracted, and a drawing is synthesized. Along the way, the true positions of the vertices in the 2D projection are perturbed due to digitization errors and the preprocessing. As most available algorithms for interpreting line drawings are "superstrict," they judge these noisy inputs as incorrect and fail to reconstruct a three-dimensional scene from them. The presented method overcomes this problem by moving the positions of all vertices until a very close correct drawing is found. The closeness criterion is to minimize the sum of squared distances from each vertex in the input drawing to its corrected position. With this tool, any superstrict method for line drawing interpretation is now practical, as it can be applied to the corrected version of the input drawing