基于质量屋与排序组织法的产品概念决策方法

为了在选择概念设计方案时实现顾客需求与专家经验知识的协调决策,提出基于质量屋与排序组织法的产品概念决策方法。通过模糊质量屋的关联矩阵与自相关矩阵进行顾客需求向产品技术特征的转换,将概念方案决策矩阵建立于质量屋的输出结果之后,利用所输出的技术特征权重值进行模糊排序组织法的综合排序,排序组织法所使用的偏好函数由专家根据产品的技术特点构造。以实例说明了所提方法的可行性和有效性。     

基于QFD和DSM的复杂产品设计任务规划方法

目前,现有的DSM方法缺乏与上游产品级用户需求和技术特性的关联,设计任务规划没有融合用户需求,因而也就无法从根本上保证最终的设计方案能够最大限度的满足用户需求。为此提出了基于QFD和DSM的复杂产品设计任务规划方法,通过构建两个质量屋实现了用户需求向产品结构的映射,之后再利用DSM进行设计任务规划,从而使得规划结果充分体现用户需求,更加合理和有效。最后,以水电机组为应用对象,对所提方法的可行性和正确性进行了验证。     

基于QFD与TRIZ技术工具的产品概念设计方法

为消除产品概念设计过程中可能产生的二层问题的负面影响，提出了一种基于质量功能配置与创造性解决问题理论的三种技术工具综合的产品概念设计方法。该方法通过质量功能配置的质量屋分析确定需要改善的零部件；在对零部件进行负相关分析的基础上，应用创造性解决问题理论技术工具提出解决一对质量特性负相关的方案；然后通过多次循环的质量功能配置分析与创造性解决问题理论技术工具应用，预测可能产生的二层问题并降低其负面影响，进而形成有效的产品概念设计方案。通过在某全自动洗衣机研发过程中的实际应用，验证了该方法的有效性和实用性。     

Integration of marketing research techniques into house of quality and product family design

Quality function deployment (QFD) is a well-known technique used for designing products and services to reflect customer needs. The first phase of QFD, usually called house of quality (HOQ), is of fundamental and strategic importance in the QFD process. Although the traditional HOQ has been successfully used for several decades, it has often been faced with a number of problems in real application cases. This paper will discuss three main problems: (1) the conceptual gap between customers and designers, (2) the existence of the possible customer segments, and (3) the need for trade-off among different levels of customer needs, which tend to come up in the early stage of the HOQ process. In order to overcome these problems, a new methodology is proposed based on the integration of two marketing research techniques: conjoint analysis and two-stage cluster analysis. Conjoint analysis is used to bridge conceptual gap and to balance different levels of customer needs. A two-stage clustering method is employed to cluster customers into different segments based on the main benefits derived from the conjoint study, and to foster the development of a product family. This paper also introduces three indices, namely, the commonality percentage, the cost reduction, and the satisfaction percentage to analyze the results of developing a generic product in comparison with a product family. A case study on office chair is put forward to illustrate the performance of the proposed methodology.     

Applying CBR to machine tool product configuration design oriented to customer requirements

Product customization is a trend in the current market-oriented manufacturing environment. However, deduction from customer requirements to design results and evaluation of design alternatives are still heavily reliant on the designer’s experience and knowledge. To solve the problem of fuzziness and uncertainty of customer requirements in product configuration, an analysis method based on the grey rough model is presented. The customer requirements can be converted into technical characteristics effectively. In addition, an optimization decision model for product planning is established to help the enterprises select the key technical characteristics under the constraints of cost and time to serve the customer to maximal satisfaction. A new case retrieval approach that combines the self-organizing map and fuzzy similarity priority ratio method is proposed in case-based design. The self-organizing map can reduce the retrieval range and increase the retrieval efficiency, and the fuzzy similarity priority ratio method can evaluate the similarity of cases comprehensively. To ensure that the final case has the best overall performance, an evaluation method of similar cases based on grey correlation analysis is proposed to evaluate similar cases to select the most suitable case. Furthermore, a computer-aided system is developed using MATLAB GUI to assist the product configuration design. The actual example and result on an ETC series machine tool product show that the proposed method is effective, rapid and accurate in the process of product configuration. The proposed methodology provides a detailed instruction for the product configuration design oriented to customer requirements.     

基于多色集合的冲压模产品结构的组合设计方法

产品结构的组合设计方法综合利用了模块化设计和设计重用等方法的优点,根据功能要求选择出一些已有的、或常用的结构模块,通过有机组合而快速设计出产品结构的可行设计方案,该方法的难点在于如何选择适当的结构模块以避免出现组合爆炸现象.论述了一种基于多色集合的产品结构组合设计的数学模型和算法,其核心思想是应用多色集合及其围道布尔矩阵等数学工具来仿真复杂的组合设计过程,并以复合冲压模的结构设计为例,说明了这种新方法的实现过程.     

Integrated approach to modularize the conceptual product family architecture

To meet the increasingly heterogeneous market, a product family strategy is needed to determine how customized variants can be derived from a common product platform within acceptable cost and time. Toward this, a suitably conceived and developed product family architecture (PFA) is important for implementing mass customization. In this paper, we present a systematic approach to modularize PFA at the early design phase, which is the conceptual design stage. The PFA can be viewed as a conceptual structure with the following three interrelated elements: module, variant, and coupling interface. Identifying variant as the external driver of architectural variation, this paper develops a variety index (VI) method to estimate effects of customization on the conceptual modules. Rather than just identification of module boundary in the product architecture, the proposed modularization method translates the variety source generated from requirements analysis into a dynamic configuration of the conceptual PFA, involving variety analysis, product modularization, and generation of product portfolio architecture. An example of a power tool design is used to demonstrate the proposed method.     

面向细分市场的产品族规划方法及应用

为有效实现产品多样化和大规模定制,研究了概念设计阶段产品族的规划方法.鉴于客户对产品品质的需求及适应动态多变市场的需要,提出了为细分市场设计产品族的观点,定义了符合细分市场需求的产品族的规划范围和内容,探讨了根据客户对细分市场产品品质的总体要求,获得具有一定竞争优势的产品族最优规划方案的系统化方法.通过规划家用轿车这一具有复杂功构对应关系的产品实例,验证了该方法的有效性和实用价值.     

人机协同的交互进化产品概念设计方法研究

为解决当前进化算法尚难完全模拟人类智能进行产品概念设计这一问题,提出了一种结合人机智能的交互协同进化方法,进行产品概念设计.利用面向对象与数据库两种技术,实现了产品设计的柔性建模,并借助交互可视化技术,使设计师通过对变量、约束、进化策略与目标权值的动态调整,在建模、搜索与评价的设计全过程实现人机协同的交互进化.最后,利用遗传算法与基于实例的推理技术,开发了人机协同的交互进化产品概念设计系统,并将其应用于注塑模结构优化设计,实例验证了该方法的有效性.     

ANP-GP approach for product variety design

Developing product variety under a robust platform provides a company with an important competitive advantage. The competitive benefits include reducing engineering costs and time to market, extending product portfolios and expanding market share. This study illustrated an algorithm based design methodology for achieving optimal product architecture. The impact of customer requirements (CRs) and the interdependencies among the CRs and components should be considered when assessing the components that are the focus of redesign in market shifts. This paper employs the analytic network process (ANP) to fulfil this requirement. The goal programming (GP) approach that incorporates the results from the ANP is then is applied to select the variant components within budget limits. Therefore, this study investigates drivers of the component variations to ensure the redesigned parts meet the requirements of specialized niches in the segment markets. Finally, an example of coffee maker design is presented to illustrate the feasibility of the proposed method.     

质量功能配置的多目标规划模型

提出了一个质量功能配置的多目标规划模型，它能够辅助产品开发人员作出有效的决策，使所设计的产品在有限的资源约束下能最大限度地满足顾客需求。该模型充分利用了质量屋中各个组成部分的信息，能够权衡、优化质量屋中存在的各种矛盾和冲突。实例研究表明，该模型是可行的和有效的     

A feature-based approach towards an integrated product model in intelligent design

Conceptual design is an early stage in the product design process, which has an essential effect on the product innovation. Existing approaches for product knowledge engineering for conceptual design always focus on knowledge modelling and organization, etc. However, the traditional approach is lack of better comprehending representation and reuse of design knowledge in conceptual design. This paper is devoted to presenting a systematic effective integrated modelling approach of principle solutions in conceptual design to make the knowledge of functional design be transferred efficiently to the subsequent principle conceptual design and structure conceptual design process, and even detail design. With the introduction of the physical quantity model, feature-based representation model of function, effect, physical quantity, working principle and structure concept are put forward step by step, and then an integrated principle solution model is presented based on the generalized assembly model. The knowledge organization method of principle solutions based on physical quantities is also proposed. Conceptual design process based on integrated modelling and knowledge organization of principle solutions is presented, which discloses that physical quantity model is a bridge across functional design, principle conceptual design and structure conceptual design. The conceptual design of new devices for decreasing resistance of petroleum equipment offshore platform is given as an example, which demonstrates that the methodology is obviously helpful to increase opportunities for product innovation in conceptual design.     

面向可适应性的稳健性产品平台规划方法

为更好地快速响应市场的多样化需求,引入面向可适应性的产品平台结构概念。根据稳健设计与可适应设计在提升产品适应外部环境变化的能力、考虑设计变更及以低成本获得高质量产品方面的一致性,提出了面向可适应性的稳健性产品平台规划方法,在产品平台规划初期就开始考虑产品的稳健性,并使设计具有可适应性,以避免后期出现大的返工。以公理设计理论为指导,通过“Zigzagging”映射,依照功能需求分析及三种类型的划分,合理提炼特征设计参数,建立产品平台的功能要求和设计参数矩阵。将灰色系统理论应用到产品平台的稳健设计中,结合试验设计与关联度方差分析,合理识别平台参数和变型参数。然后分两阶段进行稳健优化,确定产品族基体产品和每个变型产品的设计参数的最佳设计方案。通过卷筒组产品族的规划实例,说明了该方法的可行性和实用性。     

Concept optimization for mechanical product using Genetic Algorithm

Conceptual design is the first step in the overall process of product design. Its intrinsic uncertainty, imprecision, and lack of information lead to the fact that current conceptual design activities in engineering have not been computerized and very few CAD systems are available to support conceptual design. In most of the current intelligent design systems, approach of principle synthesis, such as morphology matrix, bond graphic, or design catalogues, is usually adopted to deal with the concept generation, in which optional concepts are generally combined and enumerated through function analysis. However, as a large number of concepts are generated, it is difficult to evaluate and optimize these design candidates using regular algorithm. It is necessary to develop a new approach or a tool to solve the concept generation. Generally speaking, concept generation is a problem of concept synthesis. In substance, this process of developing design candidate is a combinatorial optimization process, viz., the process of concept generation can be regarded as a solution for a state-place composed of multi-concepts. In this paper, genetic algorithm is utilized as a feasible tool to solve the problem of combinatorial optimizalion in concept generation, in which the encoding method of morphology matrix based on function analysis is applied, and a sequence of optimal concepts are generated through the search and iterative process which is controlled by genetic operators, including selection, crossover, mutation, and reproduction in GA. Several crucial problems on GA are discussed in this paper, such as the calculation of fitness value and the criteria for heredity termination, which have a heavy effect on selection of better concepts. The feasibility and intellectualization of the proposed approach are demonstrated with an engineering case. In this work concept generation is implemented using GA, which can facilitate not only generating several better concepts, but also selecting the best concept. Thus optimal concepts can be conveniently developed and design efficiency can be greatly improved.     

An optimised part-selection strategy in product reconfiguration design

Effective reuse of used parts and design experience help keep costs down and maintain a short time-to-market product cycle. Part selection aims to select pre-defined parts which can be connected in certain ways to perform some high-level functionality. Constraints are critical to the part-selection problem and are used to represent the function requirements that are decomposed or derived from design knowledge and particular customer needs. In this paper, constraints in part selection are discussed and classified into two basic types: part local constraints and part reconfiguration constraints. This paper mainly discusses part reconfiguration constraints, which are further classified into two categories: monotonic reconfiguration constraints and complex reconfiguration constraints. The part selection process is comprised of a series of decisions in a real product reconfiguration design process. The order of decisions is believed to have a significant effect on the development of the product reconfiguration design. The concept of effective selection range function was introduced to compute the total effective selection range, and a heuristic algorithm based on it is proposed in this paper, which aims to make the search process convergent with feasible results as well as to retain the maximum total effective part selection range. A case study is given and some conclusions are presented.     

Concept optimization for mechanical product by using ant colony system

The aim of conceptual design is to generate the best design candidate. Concept solving in conceptual design can be viewed as a problem of combinatorial optimization, in which there exists a “combinational explosion” phenomenon when using the traditional morphological matrix method to tackle it. In this research, a concept optimization problem is studied based on an Ant Colony System (ACS). By analyzing the similarity between concept solving and Traveling Salesman Problem (TSP), concept solving is transformed into a problem of optimal path in combinatorial optimization, where the dynamic programming based solution space model and the longest path based optimization model are developed. Then, the ant algorithm to resolve TSP is adopted to implement concept optimization according to the positive feedback searching mechanism of ACS, and some improvements are made incorporating crossover and mutation operators of a genetic algorithm (GA), to obtain the optimal scheme rapidly and effectively. Finally, a conceptual design case of press is given to demonstrate the feasibility and rationality of this proposed approach. The employment of ACS enables concept solving to be implemented with an algorithm and thus possesses better operability, which offers a promising way to solve the “combinatorial explosion” problem in conceptual design.     

Multi-objective optimization and evaluation method of modular product configuration design scheme

Product configuration is one of the key technologies for mass customization. Traditional product configuration optimization targets are mostly single. In this paper, an approach based on multi-objective genetic optimization algorithm and fuzzy-based select mechanism is proposed to solve the multi-objective configuration optimization problem. Firstly, the multi-objective optimization mathematical model of product configuration is constructed, the objective functions are performance, cost, and time. Then, a method based on improved non-dominated sorting genetic algorithm (NSGA-II) is proposed to solve the configuration design optimization problem. As a result, the Pareto-optimal set is acquired by NSGA-II. Due to the imprecise nature of human decision, a fuzzy-based configuration scheme evaluation and select mechanism is proposed consequently, which helps extract the best compromise solution from the Pareto-optimal set. The proposed multi-objective genetic algorithm is compared with two other established multi-objective optimization algorithms, and the results reveal that the proposed genetic algorithm outperforms the others in terms of product configuration optimization problem. At last, an example of air compressor multi-objective configuration optimization is used to demonstrate the feasibility and validity of the proposed method.     

Research on collaborative conceptual design based on distributed knowledge resource

Conceptual design is an early stage of the whole product development process, which involves the generation of solutions to satisfy the design requirements. It is a crucial issue on how to find proper principle solutions from enormous, isomeric, and even distributed knowledge resources repositories and then ally with these correlative distributed knowledge resources providers to collaborative conceptual design. Design is a task-solving process using corresponding resource, so it does not always have an agency in product design. This paper proposes a model of collaborative conceptual design based on distributed knowledge resources, which is centered on design tasks and based on dynamic knowledge alliance without agency. After a model of knowledge resource unit and a model of Web services based on knowledge resource are proposed, a virtual quantitative and qualitative knowledge resource representation based on knowledge grid is then put forward. The mixed knowledge resource repository is also proposed to support collaborative conceptual design. The strategies of knowledge register, publish, storage, reorganization, orientation, and problem solving based on mixed knowledge resource repository are then discussed in detail. The data exchange mode of principle solutions is then described. The selection strategy of dynamic knowledge alliance members is established. The framework of distributed knowledge resource is also put forward to support collaborative conceptual design. The process of collaborative conceptual design based on distributed knowledge resource is then proposed. The conceptual design of new devices for decreasing resistance of amphibious vehicles is given as an example, which demonstrates that the methodology is obviously helpful to produce valuable principle solutions with distributed knowledge for product innovation.     

A tolerancing optimisation method for product design

Although extensive research has been carried out in the area of tolerancing techniques for product design, concurrent engineering is still very seldom used in this context. This paper introduces a unique tolerancing method which applies the concept of concurrent engineering. The proposed method essentially allocates the required functional assembly tolerances to the component tolerances by formulating the tolerancing problem into a mathematical model and solving the model using a linear programming approach. The component tolerances are first represented in terms of the process tolerances, assigned by process planners at an early stage of the product design. The objective function of the mathematical model, which is to maximise the residual tolerances of the processes, is then established and the constraints formulated based on the assembly requirements and process constraints. The model is subsequently solved using a linear programming approach. Finally, the proposed method is tested on a practical example.     

A quality function deployment methodology with signal and noise ratio for improvement of Wasserman’s weights

Quality function deployment (QFD) has attracted much attention in not only the quality management field but also other engineering fields. The original concept of QFD is focused only on the voice of customers, which means that the needs of customers should be satisfied from the design stage of products. However, some problems were found in using subjective and qualitative data when constructing a house of quality (HOQ). To solve the problems, Wasserman presented a methodology to consider correlation weights on the top matrix of HOQ, but the weights are subjective data and can not guarantee consistency and objectivity. The Wasserman’s weights are randomly determined under subjective conditions. This research applies Taguchi’s robust design method as another method for obtaining the HOQ top matrix weights. With the new weights, S/N-QFD is deployed, and the result of S/N-QFD is compared with W-QFD. As an application example, with a real process and quality data of a representative company product, the relationship and the correlation between the process characteristics and the quality characteristics are analyzed. Finally, this paper presents a new QFD processing methodology to determine the weights with more consistent and objective data.