共查询到19条相似文献,搜索用时 46 毫秒
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拆卸序列生成是拆卸工艺及规划的重要内容之一。针对拆卸序列规划过程中的可行拆卸序列遗漏问题,首先阐述了拆卸约束图(disassembly constraint graph,DCG)理论,提出了一种基于干涉矩阵的邻接点判断方法,结合拆卸约束图,建立拆卸模型,给出了生成产品所有可行拆卸序列的算法。最后,给出了一个生成可行拆卸序列实例,验证了这一方法的可行性及其有效性。关键词:拆卸;拆卸序列规划;拆卸约束图;干涉矩阵 相似文献
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一种基于子装配体识别的装配顺序生成 总被引:2,自引:0,他引:2
装配体表达为装配连接图,在识别子装配的基础上,给出了简化装配体装配顺序的确定方法。文中对子装配的识别原则和装配顺序、装配方向的确定等问题进行了详细的阐述。 相似文献
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为提高装配序列规划求解效率和自动化水平,给出了装配体联结图模型、干涉向量和接触向量模型的有序二叉决策图描述,建立了基于符号有序二叉决策图模型及操作的可行装配序列生成技术.结合实例验证了基于有序二叉决策图的装配体模型和可行装配序列生成技术的正确性和可行性. 相似文献
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针对装配序列规划中组合爆炸及所生成装配序列的工程有效性不高的问题,提出了在层次模型基础上,对零件间装配关系进行人机协同量化,然后分层次、在子装配体范围内进行装配序列规划,最后结合柱塞泵的装配实例,验证了采用该方法能生成工程有效性较高的装配序列。 相似文献
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Automatic Subassembly Detection from a Product Model for Disassembly Sequence Generation 总被引:8,自引:2,他引:6
N. S. Ong Y. C. Wong 《The International Journal of Advanced Manufacturing Technology》1999,15(6):425-431
The time taken for the generation of assembly or disassembly sequences is proportional to the number of components in the
assembled product. For each additional component considered, the number of possible sequences to assemble (or disassemble
the product) increases combinatorially. Research work had been carried out to reduce this complexity so that unfeasible assembly
sequences could be discounted. A significant approach to further reduce the time for the generation of the assembly sequences
is to group components together into subassemblies and then to treat these subassemblies as "individual components". This
will reduce the number of components involved in the search or generation of assembly sequences, and hence reducing the sequence
generation time. This paper presents a methodology for automatically extracting subassemblies from a product in order to simplify
the disassembly or assembly sequence generation. 相似文献
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Mechanical Product Disassembly Sequence and Path Planning Based on Knowledge and Geometric Reasoning 总被引:2,自引:0,他引:2
D. Hu Y. Hu C. Li 《The International Journal of Advanced Manufacturing Technology》2002,19(9):688-696
A feature-based assembly model is proposed for disassembly sequence planning, and establishing a correct and practical disassembly
path for the part in the product, based on geometric reasoning and knowledge. The fundamental assembly modelling strategy
for a product is based on the mating features of its parts.
An algorithm is introduced which uses the information provided by the mating features of parts in the product to find the
candidate parts for disassembly and to carry out disassembly path planning. A complete and accurate interference checking
approach is used to ensure no global collision while disassembling a part.
In some cases, it cannot be implemented by geometric reasoning alone, so a set of criteria and heuristic rules based on knowledge,
constraints, relationships among parts, and quantitative disassemblability assessment are used. It can also be carried out
interactively by the user when necessary.
The proposed method is integrated with the CAD model of the product. The user can visually disassemble the product while planning,
so it is easier to carry out the disassembly planning and generate an optimal sequence. 相似文献
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基于Pareto解集蚁群算法的拆卸序列规划 总被引:7,自引:1,他引:7
为提高产品拆卸序列规划的效率,分析拆卸序列规划问题中的多个优化目标平衡问题,提出一种基于Pareto解集的多目标蚁群优化算法求解此类拆卸规划问题,并给出拆卸序列的构建过程。通过利用拆卸矩阵推导拆卸可行条件,获得可以执行拆卸操作的零件及其可行的拆卸方向。通过利用零件的轴向包围盒(Axis aligned bounding boxes,AABB)计算零件的拆卸行程。考虑拆卸方向改变次数、拆卸总行程、拆卸零件数量为优化目标,通过利用蚁群算法搜索可行解并计算各个解之间的支配关系,得到Pareto解集,实现求解优化的拆卸序列,给出算法的具体步骤。最后以单杠发动机为拆卸实例,利用所提方法进行拆卸序列规划求解,通过分析试验结果,并对比典型的单目标蚁群规划算法,证明了该方法的高效性和可行性。 相似文献
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如何将所有可行的拆卸路径进行紧凑、合理的表达是实现产品拆卸路径规划时首要解决的问题.为此,要对指定拆卸类型下的装配体进行有效的子装配体聚类.为在产品拆卸路径规划中实现子装配体聚类的优化,同时避免传统方法所造成的组合爆炸等问题,引用并扩展了表达零件问紧密程度的配合关系等概念,并结合对装配结构和装配过程的深入分析,提出符合工程语义的广义轴理论以及拆卸优先级修正系数等概念.在具体操作上,首先借助邻接矩阵的表达形式并结合同轴度系数函数和拆卸优先级别系数分配表等对应关系得到同轴隶属度矩阵及其修正矩阵.然后,结合模糊数学中模糊聚类分析的有关算法,得到具有传递性的模糊等价矩阵以及分属不同截距下的动态产品聚类关系图.最后,结合此关系图和拆卸优先级别系数分配表,实现子装配体的聚类优化.经验证,所提方法增强了拆卸路径划分同工程实际的一致性,同时减少了计算工作量. 相似文献
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A Novel Representation Scheme for Disassembly Sequence Planning 总被引:3,自引:1,他引:3
J. R. Li L. P. Khoo S. B. Tor 《The International Journal of Advanced Manufacturing Technology》2002,20(8):621-630
The representation of the disassembly sequence is a key issue in maintenance planning. It involves a highly constrained combinatory
problem, which is coupled with varying start and end nodes. These start and end nodes are dependent upon the nature of a maintenance
task. In this paper, different representation and modelling schemes for disassembly sequence planning are first reviewed.
Then, a novel representation scheme for disassembly sequence, which is generic and can be used to represent both the geometrical
and precedence constraints dynamically in product disassembly, is proposed. Based on such a representation scheme, the process
for the determination of possible disassembly sequences can be simplified. By taking into consideration disassembly constraints,
the optimal disassembly sequence in relation to the component to be maintained (target component) can be quickly derived.
This is achieved by pruning the search space of disassembly sequences, grouping related components into subassemblies, and
identifying free components to facilitate disassembly oper-ations. Subsequently, the optimal disassembly sequence in relation
to the target component can be obtained using genetic algorithms. In this manner, the disassembly sequences for a complex
product comprising a relatively large number of components can be derived within a short time. A case study is used to illustrate
the effectiveness of the representation scheme. Comparisons are made using the same case study with the AND/OR graph representation
and the Petri net approach for disassembly sequence planning. The results show that the proposed representation scheme is
simpler and is more efficient than the rest.
ID="A1" Correspondence and offprint requests to: Dr L. P. Khoo, School of Mechanical and Production Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore
639798. E-mail: mlpkhoo@nyu.edu.sg 相似文献
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F. Torres S.T. Puente R. Aracil 《The International Journal of Advanced Manufacturing Technology》2003,21(5):317-327
An algorithm is presented that is based on a representation method for products, which lets us show, intuitively, the hierarchical
relationships among components and/or assemblies of the product. This paper presents an algorithm for establishing a partial
non-destructive disassembly sequence of a product. The disassembly sequence can be obtained for a component as well as for
a sub-assembly (group of different components). The disassembly sequence is obtained autonomously and automatically and can
be used in a flexible manufacturing system.
ID="A1"Correspondance and offprint requests to: F. Torres, Department of Physics, Systems Engineering and Signal Theory, University of Alicante, Crta San Vicente s/n, PO
Box 99, Alicante, Spain. E-mail: ftorres@disc.ua.es 相似文献
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在总结特征识别方法的基础上 ,充分考虑轴类部件自身的形状特点 ,应用特征识别技术 ,建立了一个面向装配顺序规划的层次装配特征信息模型。给出了在无需初始化装配的情况下 ,轴类部件装配顺序规划的算法。并在MDT环境中 ,应用MCAD -API技术进行了实现 相似文献