基于遗传算法的飞机装配序列规划优化方法

在基于割集的装配顺序规划方法中，随着零件的增加，装配序列数呈指数增加，由此导致算法的组合爆炸问题。为此，提出了基于．遗传算法的装配序列规划优化方法，研究了零件装配信息的基因组表示方法，将参与装配的零件的基因组排列成序，实现装配顺序的染色体表示。采用模糊集理论建立了适应度函数，并对装配序列进行评价和优化。以某型飞机机翼产品为例，验证了技术的有效性。     

基于特征语义的装配序列规划预处理方法

针对复杂产品装配序列规划复杂度高、求解效率低下的问题，提出了基于典型零件装配语义规则的装配序列规划预处理方法。构建基于特征的装配语义模型，表达零件的类型与几何特征信息，在此基础上构建典型零件装配特征库；通过基于属性邻接图的匹配方法，进行零件类型识别及子特征分割；基于典型零件的装配规则，建立装配序列规划矩阵的降维方法，提出基于装配序列规划矩阵的装配可行序列生成方法；以主动锥齿轮子装配为例验证了方法的有效性。     

基于基础件和连接关系的装配序列自动快速规划研究

对计算机装配序列快速规划进行了研究,为提高装配序列规划的效率,提出建立集成装配模型。该模型把零件基本属性信息、产品层次信息和关系信息作为基础信息,把连接信息作为衍生信息。为避免装配序列误判,提出把基础件作为装配序列的产生载体,来避免壳体类零件、轴类零件在连接关系中的误判,并结合减速器给出了具体的算法,进而说明基于基础件和连接关系的装配序列规划的优点。因此,该模型可支持自动实现复杂产品装配序列的计算机自动规划,可广泛应用于汽车、机器人等多零件产品的装配顺序规划。     

装配规划中基于割集的装配顺序生成方法

针对装配规划提出一种新的装配零件关系的描述方法，该方法应用改进的关联图－优先约束关联图，描述装配零件间的连接关系、优先关系及约束关系。在生成产品装配顺序时，充分地把装配优先关系与割集法副合到装配顺序搜索中，有效地生成产品所有满足装配条件的装配顺序，为装配规划提供参考的装配工艺路径。     

产品装配顺序规划方法的研究

计算机辅助装配顺序规划是有关产品装配研究的重要内容。在提高装配顺序规划质量的条件下，综合拆分法与优先约束法的优点，提出了一种装配顺序规划的新方法。在子装配、组件预识别的基础上，采用割集法将产品进行拆分。基于装配城信息建立零件几何优先关系，基于产品共性特征及个性特征建立工艺优先关系，最终生成合理可行的装配顺序，并对实例进行分析。     

定位关系在装配序列规划中的应用研究

为提高产品仿真装配效率和满足装配工艺要求,提出一种基于定位关系分析的分类装配序列规划方法.首先对零件的装配特征属性进行预定义和分类,然后根据装配零件的联接关系,在可行拆装方向上建立所有邻接零件的定位关系链有向图;按照定位链顺序依次对零件进行干涉检测并更新其定位关系,最终获得可行装配序列.实例表明,该方法简化了模型的装配关系并有效缩小其装配序列解空间,在一定程度上提高了装配规划效率,并通过虚拟拆装仿真过程验证其生成序列的正确性和可行性.     

粒子群算法在抽油机装配序列规划中的应用研究

在石油机械的产品的装配过程中,此类机械产品的装配顺序优化具有多目标和非线性的特点,针对传统算法在该问题求解上的不足,以及根据此类产品实际的装配规划问题的特点和要求提出一种新的通过粒子群优化算法进行抽油机的装配顺序优化。该方法重新定义了微粒的位置和速度以及相关的各种操作,综合考虑零件装配几何性、装配稳定性以及装配方向改变次数等信息对装配序列的影响,建立了适应度函数,并对装配序列进行了优化。以抽油机产品的装配为例,验证了技术的有效性。     

逐步求解的装配顺序规划方法

产品装配是一个为已装配体尚未完成装配的配合寻找可装配件的过程。针对该特点,提出逐步评判的装配顺序求解方法。建立装配规划约束的编码矩阵,采用混合编码的方式表示几何约束和语义约束。以混合编码矩阵为基础,通过装配约束推理和判断获得产品装配过程每一步的可行装配方案,作为装配顺序评价集。以装配方向改变、装配工具改变、装配体的稳定性和装配准确度要求作为规划因素集,运用多因素模糊综合评判方法为已装配体获取最优的装配方案,逐步缩小求解空间,直到规划完成所有零件的装配顺序。将该方法应用于某机型舱门骨架装配规划中,结果表明该方法合理、有效,能够满足工程实际需求。     

机器人自动装配的神经网络规划方法

讨论了一种用神经网络来实现自动装配规划的方法。这种方法首先利用优先约束知识来表示所有产品零件的装配先后关系，然后利用Ｈｏｐｆｉｅｌｄ神经网络来求解满足此优先约束条件的最佳的产品装配序列，最后给出仿真结果。     

支持变约束的装配顺序随需式规划方法

针对复杂产品装配约束变更,引起装配顺序被迫变化的问题,以产品装配现场零件、工装、资源失效等情况为例,通过对装配顺序非常规规划的特征分析,提出基于灰色理论结合遗传算法的方式解决装配顺序非常规规划问题.建立基于复合基因组的基因7元组编码机制,考虑装配约束关系,提出综合装配并行度、子装配稳定性、装配聚合性、装配重定向性的适应度函数表示方法,通过遗传操作,有效生成由变动环节开始的装配顺序各择集.将遗传算法生成的装配顺序备择集作为灰色决策集,建立灰色关联模型,结合原始装配顺序,建立装配顺序参考序列,进行灰色关联分析,求解理想最优或次优装配顺序,实现复杂产品装配顺序非常规规划.将所提算法应用于某机型组件装配中,验证算法的有效性.     

A green assembly sequence planning model with a closed-loop assembly and disassembly sequence planning using a particle swarm optimization method

In a green product life cycle, it is necessary to determine how to disassemble a product before the product is planned to be assembled. In this research, a green assembly sequence planning model is developed. A closed-loop assembly sequence planning model is presented by integrating assembly and disassembly sequence planning models. For an assembled product, an assembly sequence planning model is required for assembling the product at the start, while a disassembly sequence planning model is performed for disassembling the product at the end. In typical assembly and disassembly sequence planning approaches, the two sequences are independently planned and evaluated. In this paper, a closed-loop model is presented to concurrently generate and evaluate the assembly and disassembly sequences. First, a graph-based model is presented for representing the feasible assembly sequences and disassembly sequences. Next, a particle swarm optimization (PSO) method with a new encoding scheme is presented. In the PSO method, the assembly and disassembly sequences can be simultaneously represented and evaluated with an objective of minimizing the total of assembly costs and disassembly costs. The test results show that the presented method is feasible and efficient for solving the integrated assembly and disassembly sequence planning problem. An example product is illustrated and discussed.     

基于子装配识别的产品拆卸序列生成研究

对含有较多零件的复杂产品拆卸方法作了讨论,提出了一种基于子装配识别的拆卸序列生成算法。根据装配连接图和干涉图识别出子装配体,然后将子装配体看作一个零件,采用装配经验知识与几何推理相结合的方法生成子装配体序列,最后以一个装配实例说明了算法的有效性。     

A converse method-based approach for assembly sequence planning with assembly tool

In order to improve the quality and efficiency of assembly sequence planning for complex mechanical product, a converse method-based approach for assembly sequence planning is proposed. Firstly, the disassembly interference matrix of product and the disassembly constraint degree of part are defined. Product disassembly sequence is obtained through geometry reasoning algorithm and the searching work of disassembly sequence is simplified by the contact constraint set. Secondly, the maneuverability of tool is inspected through the using matrix and interference matrix of assembly tool. The infeasible disassembly sequence is excluded and product assembly sequence is obtained by reversing the order of disassembly sequence. Thirdly, the evaluation mechanism for assembly sequence is established to get the optimal assembly sequence and the optimal assembly sequence is selected by calculating the value of evaluation function. Finally, a vibration generator is illustrated to verify the validity and feasibility of the proposed approach.     

基于CATIA中DELMIA的虚拟装配技术的应用

以某产品的模具为例,对虚拟装配技术在模具产品上的运用进行了初步的探讨,从虚拟装配的实现流程、产品的层次结构划分、装配顺序规划及路径规划进行了分析,并基于CATIA实现了该产品组件的装配过程仿真,确定了合理的装配顺序和路径,为虚拟装配技术在产品上的深入应用提供了有益的探索。结合装配工艺的特点和要求,提出了基于虚拟装配技术进行装配工艺设计的流程;最后针对装配工艺设计的实现方法和软件系统做了概述。     

A novel approach to the geometric feasibility analysis for fast assembly tool reasoning

A product assembly or disassembly is completed by means of proper tools. The selection of feasible tools is an important process in planning a complete assembly or disassembly sequence. A key tooling consideration in assembly or disassembly planning is to reason the available space for a tool application during the assembly or disassembly of a product. Currently, assembly tool reasoning about space mainly depends on simulation-based or user-interactive approaches because of its computational complexity. These approaches are inappropriate in dealing with various what-if scenarios regarding assembly or disassembly planning in a rapid product development. They also depend on users’ expertise or experience in assembly or disassembly. This paper presents a novel approach to the geometric feasibility analysis for fast assembly tool reasoning. Techniques described in this paper are advantageous not only in the aid of generating a complete assembly or disassembly plan but also in the efficient support of such systems as computer-aided assembly planning (CAAP), design for manufacturing (DFM), design for assembly (DFA), design for disassembly (DFD), and computer-aided tool selection (CATS).     

Mechanical Product Disassembly Sequence and Path Planning Based on Knowledge and Geometric Reasoning

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.     

基于虚拟现实和仿生算法的装配序列优化

针对自动装配规划和交互式规划都存在不足,将虚拟现实和仿生算法结合起来,提出一种生成优化装配序列的新方法.建立基于几何约束的虚拟装配环境,在该环境中根据经验和知识进行交互式拆卸,定义优先约束表来表达零件间的优先约束关系.应用蚁群算法规划出初始优化的装配顺序,再在虚拟环境下进行仿真、评价和优化,考虑装配位置可达性和工具操作等因素,识别新的优先约束和评价准则,重新规划出更优的装配顺序,不断反复和完善,直到得到满意的最佳装配顺序为止.通过实例验证该方法有效性.     

An intelligent interactive approach for assembly process planning based on hierarchical classification of parts

Assembly process planning is a difficult problem in the product design and development process. In order to reduce the difficulty of assembly process planning (APP), this paper presents an approach to finding a practical plan for assembly process through the intelligent interactive method based on hierarchical classification of parts. First, two hierarchical classification principles towards interactive disassembly are presented based on the key assembly constraint (KAC). Then, the initial assembly relationship of the product is readjusted to a new hierarchical structure which is more suitable for assembly planning according to a novel hierarchical classification algorithm. On the basis of the new hierarchy of product, an intelligent disassembly-based approach is presented, which not only takes full advantage of the ant colony algorithm for searching and constructing an initial assembly sequence with three available assembly principles, but also makes full use of the experience and knowledge of the human being for achieving a better assembly process. The intelligent disassembly approach can achieve an optimized assembly sequence, paths and scheme necessary information regarding the required assembly fixtures and tools. Finally, a case study shows that the proposed approach is feasible and practical.     

装配工艺规划后处理的研究与应用

装配工艺规划是产品装配活动中的一个关键环节 ,直接影响着产品的质量和装配费用。计算机辅助装配工艺规划 (CAAPP ,ComputerAidedAssemblyProcessPlanning)在一定程度上提高了装配工艺规划的效率 ,然而它并不能完成装配工艺规划中的所有活动。装配工艺规划后处理是装配工艺规划的重要组成部分 ,它作为CAAPP的有效补充 ,利用计算机辅助手段进一步提高了装配工艺规划的自动化水平。本文提出了装配工艺规划后处理的体系结构 ,并从装配信息建模、装配工艺文件的生成和装配资源共享与信息转换三个方面对其关键技术进行了较为系统的研究