Community Detection to Split Large-scale Assemblies in Subassemblies

The motivation for the preprocessing of large-scale CAD models for assembly-by-disassembly approaches. The assembly-by-disassembly is only suitable for assemblies with a small number of parts (n_{parts} &lt; 22). However, when dealing with large-scale products with high complexity, the CAD models may not contain feasible subassemblies (e.g. with connected and interference-free parts) and have too many parts to be processed with assembly-by-disassembly. Product designers' preferences during the design phase might not be ideal for assembly-by-disassembly processing because they do not consider subassembly feasibility and the number of parts per subassembly concisely. An automated preprocessing approach is proposed to address this issue by splitting the model into manageable partitions using community detection. This will allow for parallelised, efficient and accurate assembly-by-disassembly of large-scale CAD models. However, applying community detection methods for automatically splitting CAD models into smaller subassemblies is a new concept and research on the suitability for ASP needs to be conducted. Therefore, the following underlying research question will be answered in this experiments: <strong>Underlying research question 2: </strong>Can automated preprocessing increase the suitability of CAD-based assembly-by-disassembly for large-scale products? A hypothesis is formulated to answer this research question, which will be utilised to design experiments for hypothesis testing. <strong>Hypothesis 2:</strong> Community detection algorithms can be applied to automatically split large-scale assemblies in suitable candidates for CAD-based AND/OR graph generation.}面向拆分式装配（assembly-by-disassembly）方法的大规模计算机辅助设计（CAD）模型预处理的研究动机。拆分式装配仅适用于零件数量较少（零件数$n_{ ext{parts}} < 22$）的装配体。然而，在处理高复杂度的大规模产品时，CAD模型可能不包含可行的子装配体（例如具备连接关系且无干涉的零件），且零件数量过多，无法采用拆分式装配方法进行处理。产品设计师在设计阶段的偏好未必适配拆分式装配流程，因为他们并未简洁考量子装配体的可行性与每个子装配体的零件数量。 为此，本文提出一种自动化预处理方法，通过社区检测（community detection）将模型划分为易于管控的分区，以此实现大规模CAD模型的并行化、高效且精准的拆分式装配。然而，采用社区检测方法自动将CAD模型拆分为更小的子装配体是一项全新的研究思路，目前仍需开展其在装配序列规划（ASP）中适用性的相关研究。因此，本实验将解答如下核心研究问题：<strong>核心研究问题2：</strong>自动化预处理能否提升基于CAD的拆分式装配对大规模产品的适配性？ 针对该研究问题，本文提出一项假设，并将其用于设计假设检验实验。<strong>假设2：</strong>社区检测算法可用于自动将大规模装配体拆分为适配基于CAD的与或图（AND/OR graph）生成的候选子装配体。