【作者】 张娜；

【导师】 杨育；

【作者基本信息】 重庆大学 ， 工业工程， 2019， 博士

【摘要】 客户需求变更在复杂机械产品设计过程中不可避免,且会造成产品设计延误及设计成本增加。当客户提出需求变更时,如何快速响应并做出科学决策是企业急需打造的核心竞争力。在此背景下,如何对复杂机械产品结构进行量化表达、如何对客户需求变更传播过程进行动态描述、如何对客户需求变更影响进行科学评估以及如何快速低成本进行产品配置更新再设计?是当前复杂机械产品设计过程中变更响应亟待解决的重要问题。针对客户需求变更,本文基于复杂网络理论对复杂机械产品进行建模并对变更响应问题进行深入研究。论文中解决的关键科学问题主要包括:面向客户需求变更的复杂机械产品结构表达、客户需求变更传播过程分析、客户需求变更影响评估以及复杂机械产品再配置设计。论文的主要研究内容简述如下:第一,为量化表达复杂机械产品结构,面向客户需求变更构建复杂机械产品模块化网络模型。首先,论文基于区间直觉模糊集从零部件间的功能相关性、物理结构相关性、客户参与度和可持续性四个方面量化产品零部件之间的关联强度;在此基础上,基于复杂网络建模理论,以零部件为网络节点、零部件之间的关联关系为网络边、零部件之间的关联强度为网络权重,构建复杂机械产品零部件关联网络模型,以实现复杂机械产品结构的量化表达。其次,将度中心性和广义介数与经典GN算法相结合,提出改进GN算法对复杂机械产品进行模块划分并构建复杂机械产品模块化网络模型。最后,以某2.5WM风力发电机组的建模及模块划分为例对本章的研究方法加以应用,验证本章研究方法的有效性。第二,为动态描述客户需求变更在复杂机械产品模块化网络模型中的传播过程,基于复杂网络传播动力学和无标度网络演化机理构建客户需求变更传播模型。根据节点在网络中的位置以及与其他节点之间的关联关系,将节点分为根节点、叶节点和中间节点三类,分析不同类型节点的变更传播特性;以无标度网络演化机理为基础,结合复杂机械产品模块化网络结构特征及拓扑特性,分析变更传播引起的网络节点的增加和删除、边的增长和删除以及节点间的择优连接;在此基础上,构建客户需求变更传播模型,该模型动态描述了上、下游节点的变更传播过程。此外,为深入揭示变更传播机理,论文计算各个时刻的变更传播速率以及已变更节点的比率,以充分反映不同初始变更节点的变更传播速率和传播范围;计算各个节点的出点强度和入点强度,以分析不同节点的传播类型;计算各个节点的中心性,以识别影响变更传播的关键零部件。最后,以风力发电机组设计过程中的客户需求变更传播过程为例对本章所提的方法加以验证,验证本文方法的有效性。第三,为准确评估客户需求变更对复杂机械产品设计的影响,提出基于网络全局参数的客户需求变更影响评估方法。首先,为提高变更传播路径的搜索效率,以初始变更节点为基准,根据节点间的关联关系,划分节点的层级,进而,提出基于节点层级划分的可行变更传播路径搜索方法。然后,为系统评估客户需求变更影响,提出基于网络全局参数的客户需求变更影响评估方法,通过该方法评估客户需求变更的积极影响和消极影响;在此基础上,提出响应客户需求变更请求的决策策略,包括效率优先策略、最小变更成本优先策略、最小变更时间优先策略三个主策略和无耦合优先策略、最近消解优先策略两个辅助策略,以指导企业对客户需求变更进行科学决策。最后,以评估风力发电机组的变更影响为例对本章的研究方法加以验证,并指导企业对客户需求变更做出科学决策。第四,接受客户需求变更请求后,为提高复杂机械产品配置更新效率,提出分别针对不同零部件类型的复杂机械产品配置更新方法。首先,提出基于复杂网络全局参数的全局通用性零部件分类方法,通过综合考虑了零部件在产品机械产品族中的使用数量及功能权重,实现更加科学的零部件分类。其次,对于通用件的配置更新,提出基于规则推理和模糊相似性方法的通用件模块配置更新和零部件参数调整相结合的复杂机械产品通用件的配置更新方法;对于定制件的配置更新,针对不同的定制件参数类型,以最小化质量损失和最大化客户满意度满意度为目标,构建定制件的配置更新模型,并运用嵌入正交杂交的差分进化算法对其求解。最后,以风力发电机组在客户需求变更驱动下的配置更新问题为例验证本章研究的有效性,结果表明本章研究方法有效提高了产品配置更新效率。综上所述,本文的研究成果以期提升复杂机械产品设计中企业对客户需求变更决策和响应的科学性和高效性,同时丰富复杂机械产品设计领域理论体系。更多还原

【Abstract】 Customer’s demand change is inevitable in the process of complex mechanical product design,those changes may cause product design delay and increase design cost.When customers put forward changes in demand,how to respond quickly and make scientific decisions is a key factor for enterprises to enhance their market competitiveness.In this context,how to quantify the structure of complex mechanical products? How to dynamically describe the propagation process of customer’s demand changes? How to scientifically evaluate the impact of customer’s demand changes? How to achieve product configuration update and redesign in a fast and low-cost way? These are all the urgent issues that need to be solved for enterprises at present.Based on the complex network theory,this paper makes a deep study of complex mechanical product structure modeling and product reconfiguration in view of customer’s demand change scenarios.The key issues in this paper include: the expression of complex mechanical product structure oriented to customer’s demand change,the analysis of communication process of customer’s demand change,the impact assessment of customer’s demand change and the reconfiguration design of complex mechanical products.The main contents of this paper are described as follows:Firstly,in order to quantitatively express the structure of complex mechanical products,a modular network model of complex mechanical products is constructed for customer’s demand changes in this paper.The main work of this section include: a)The relationship between different parts were expressed based on interval intuitionistic fuzzy sets from four aspects: functional correlation,physical structure correlation,customer participation and sustainability;On this basis,the related network model of the parts of complex mechanical products is constructed based on the complex network modeling theory,which be used to quantitative expression of the structure of complex mechanical products,here,the part as the network node,the relationship between parts as the network edge,the relevance strength as the network weight.b)In order to accurately divide the module of complex mechanical products,an improved GN algorithm is proposed to divide the module of complex mechanical products to construct the modular network model of complex mechanical products,the improved algorithm is mainly embodied in the combination of degree centrality and generalized median with classical GN algorithm.c)A 2.5WM wind turbine model and module division case be used to validate the research model and method in this chapter.Secondly,in order to dynamically describe the transmission process of customer’s demand change in the modular network model of complex mechanical products,the dissemination model of customer’s demand change was constructed based on the complex network propagation dynamics and scale-free network evolution mechanism.The main work of this section include: a)The nodes are divided into root node,leaf node and intermediate node according to the location of nodes in the network and the relationship with other nodes,then,the change propagation characteristics of different types of nodes was analyzed;b)Based on the evolution mechanism of scale-free network,combined with the structural and topological characteristics of modular network of complex mechanical products,the increase and deletion of network nodes,the growth and deletion of edges,the optimal connections between nodes caused by change propagation are analyzed.Then,combined with SI classical propagation model,the dissemination model of customer’s demand change in complex mechanical product modular network is constructed.This model dynamically describes the process of upstream node change dissemination and downstream node change dissemination.In order to reveal the mechanism of change propagation,Calculate the change propagation rate and the ratio of changed nodes at each time to fully reflect the change propagation rate and range of different initial changed nodes;Calculate the strength of outgoing and inbound nodes to analyze the propagation types and cost of different nodes;Calculate the centrality of nodes to identify key components that affect change propagation;Taking a wind turbine design process as a case study,the effectiveness of the proposed method is verified.Thirdly,in order to accurately evaluate the impact of customer’s demand change on complex mechanical product design and make scientific decision on customer change,a method of customer’s demand change impact assessment is proposed based on global parameters of network.The main work of this section include: a)In order to improve the search efficiency of change propagation path,on the basis of transforming the two-way relationship of network nodes into one-way relationship,taking the initial change node as the benchmark,the hierarchy of nodes is divided according to the association relationship between nodes,then a feasible change propagation path search method is proposed based on node hierarchy division;b)In order to systematically evaluate the impact of customer demand change,a method of customer demand change impact assessment based on network global parameters is proposed,which evaluates the positive impact of customer’s demand change(customer’s satisfaction and product performance)and the negative impact of customer’s demand change(transmission range of change,additional change cost and additional change time);on this basis,a method of customer’s demand change impact assessment is proposed.Here,the decision-making strategies responding to customer’s demand change requests include three main strategies and two auxiliary strategies: the main strategies including efficiency-first strategy,minimum change cost-first strategy,minimum change time-first strategy;the auxiliary strategies including uncoupled priority strategy and latest elimination priority strategy,which can assist enterprises to make scientific decisions for the customer’s demand change;c)A wind turbine is taken as a case study to validate the research method in this chapter.The results show that the research method proposed in this paper is effective and can guide enterprises to make scientific decisions on customer’s demand changes.Fourthly,in order to improve the design efficiency of product reconfiguration after accepting customer’s change requests,the configuration updating methods for complex mechanical products with different parts types are proposed.The main work of this section include: a)On the basis of existing research results,a global general parts classification method is proposed based on global parameters of complex network,which divides parts into standard parts,general parts and customized parts.This method effectively takes into account the number and functional weight of parts used in product machinery product family,achieving more scientific parts classification.b)For configuration updating of general parts,a method of configuration updating for general parts of complex mechanical products is proposed based on rule reasoning and fuzzy similarity method,which combines configuration updating of general parts module and parameter adjustment of parts.For the configuration updating of customized parts,considering the quality loss of parts,the configuration updating model of customized parts is constructed from two aspects: the bigger the better and the smaller the better.The model is solved by using evolution algorithm with embedded orthogonal hybridization.The algorithm effectively solves the issue that 0-1 integer variables are difficult to integrate into the evolutionary process.c)The effectiveness of the research method in this chapter is verified by solving the configuration updating issue of a wind turbine driven with customer’s demand change.The results show that the research method in this chapter effectively improves the efficiency of product configuration updating.In summary,the research results of this paper are devoted to improving the scientific and efficient decision-making when the enterprises response to customer’s demand changes in the process of complex mechanical product design.At the same time,the research results of this paper are expected to enrich and expand the theoretical system of complex mechanical product design field.更多还原