The integration and application of MCAD and ECAD in the spatial design of electronic products

As mechanical computer-aided design (MCAD) and electronic computer-aided design (ECAD) are used for electronic design and mechanical design, respectively, engineers need to transmit design information between the two through an intermediate data format (IDF). If there are several sub-restrictive areas in the restrictive areas when MCAD is adopted to plan the restrictive areas of electronic components, engineers must re-divide the areas to form a separate and closed loop. Only by doing so will they be able to obtain output IDF files. Nowadays, electronic design has become increasingly complicated, and so it takes a lot of time to finish such a design. Worse still, missing a step results in wrong information, which affects the cost and efficiency of product development. This study sets up an algorithm for restrictive areas synthesis and applies it to the pre-processing of output IDF files. This study also summarizes the bottlenecks of area synthesis and corresponding solutions. Aside from automatic synthesis, the algorithm enhances the integration of MCAD and ECAD, thus achieving fast modification of electronic and mechanical designs between the two and allowing for further examination. The methods herein can reduce the design time by over 65% and prevent errors.     

三维信息模型协同编辑技术及系统

对现有协同设计系统在协同编辑方面的工作进行研究，在分析它们研究对象和方法的基础上，结合MCAM对大型三维信息模型设计的需要，提出并开发了网络MCAM系统。利用基于“消息”的通信机制，将设计中对三维信息模型的编辑过程包装为网络传输的“消息”，大大减少了网络传输中的数据量，并较好的实现了三维信息模型的协同编辑技术。     

Generating significant subassemblies from 3D assembly models for design reuse

Significant subassemblies are defined as the reusable regions of pre-existing 3D assembly models. A significant subassembly has great significances for design reuse as it aggregates abundant knowledge in a vivid 3D CAD model and enables designers to reuse existing mature designs from a high-level perspective. Consequently, this paper contributes to significant subassembly generation from pre-existing 3D assembly models for design reuse. The paper first gives an explicit definition of significant subassemblies and further explores the multilevel knowledge embedded in these significant subassemblies. Based on the above definition and multilevel knowledge, a knowledge-based approach is then proposed for significant subassembly generation, which includes three phases: (1) identifying candidate subassemblies with high cohesion inside and low coupling outside using the Markov clustering process; (2) removing normal candidate subassemblies with low reusability and less information, and generating filtered subassemblies using the proposed assembly frequency – inverse mean subassembly frequency based scheme; and (3) determining significant subassemblies by measuring the complexity of the filtered subassemblies. Finally, a computer numerical control honing machine model is taken as an application example to demonstrate the effectiveness of the proposed approach.