Support value of sketching in the design process

This study presents an experimental investigation dealing with the support value of sketching activity in the early stages of the design process. The main focus is the process of sketching, including the sketching activity and the simultaneous use of the produced sketches. Sketching has a positive impact on the quality of the designed solution and on the individual experience of the design process. The quality of the solution concepts increases from entirely mental design problem solving without external support over partly supported to completely supported problem solving. On the basis of a representative case, the procedure of sketching and the activities performed while generating a design solution are analysed. A continuous change between internal mental and external materializing activities can be seen in the design process. Electronic Publication     

Teaching engineering design: Can reading a textbook make a difference?

Teaching design is an integral part of most engineering curricula. Often, students are introduced to the engineering design process through a chapter in a textbook. Does this passive approach to teaching an active process aid the students' learning? An experiment was conducted to assess what students learn about the design process when they read a text. Here, 10 students enrolled in a freshman course were asked to read aloud from a freshmen engineering textbook. Half of the subjects read the text prior to solving three open-ended engineering design problems and the other half solved the same problems before they read the text. Both the subjects' process in solving the problems, as well as the quality of their solutions (the product), are assessed. Results show that subjects that read the text before they solved the three problems spent significantly more time solving the problems and were more sophisticated in their problem solving strategies. These subjects also scored better when judged on the quality of their approach to the problem (including the number of design criteria considered, communications, assumptions, and technical accuracy). However, these subjects did not score better on a quality measure of the final solution.     

Design and other types of fixation

Design educators often comment on the difficulties that result from a premature commitment by students to a solution to a design problem. Similarly practitioners can find it difficult to move away from an idea they have developed or precedents in a field. In the psychology of problem solving this effect is called functional fixedness or fixation. It is not surprising that these effects should occur in design problem solving. However, while these types of issues have been discussed in the context of design, there has been little systematic evidence available about whether or not and under what conditions design fixation does occur. The paper reviews the results of a series of recent experiments which begin to address these issues. The results of the experiments are examined in terms of what insights they provide into the design process, what implications they have for design education and how they relate to the larger and more general area of human problem solving.     

可拓与TRIZ融合辅助设计思维过程研究

目的 构建完善的设计思维过程模型,提高设计思维方法的客观性和可操作性。方法 将可拓和TRIZ融合对设计思维过程中问题分析、求解和评价三个重要阶段进行优化。利用可拓模型建立形式化问题定义模型;集成可拓与TRIZ求解工具,构建问题求解模型;融合TRIZ理想度法则和可拓优度评价,提出理想优度评价方法。结果 构建了可拓与TRIZ融合辅助的设计思维过程模型,并通过智能购物车的设计验证了该模型的合理性和可行性。结论 所构建的基于可拓与TRIZ融合的设计思维过程模型更具客观性和可操作性,对于支持产品创新设计实践具有重要意义。     

基于U-TRIZ理论的产品概念设计SAFC模型分析

目的 针对经典TRIZ体系过于庞大,解题工具之间缺乏集成联系,以及难以掌握和运用等现状,通过运用U-TRIZ理论以功能为导向,以属性为核心,将因果分析模型和功能分析模型通过物质属性有机地集成,构建的物质—属性—功能—因果（SAFC）分析模型将有效解决上述问题。方法 分析SAFC模型在产品概念设计过程中的应用现状和研究进展,综述SAFC分析模型在矛盾类型问题求解、置换型问题求解、内调型问题求解的解题方法,给出SAFC分析模型的基本构成、功能因果链绘制图和差异性特征展示表,阐述U-TRIZ理论的解题流程总框架。结果 SAFC模型是一个从物场模型到功能模型演化而成的实用问题分析工具,有多种问题解题模式,能有效解决各种问题。结论 以智能手机概要设计为例,验证了SAFC分析模型的相关解题方法,该研究将为手机企业寻找创新方向和解决工程难题,提供一种可供借鉴的解决方案。     

基于TRIZ及ABD的创新设计研究

应用基于类比的设计（ABD）和发明问题解决理论（TRIZ）的设计过程均要采用已往成功的设计实例,使两种过程具有相似性; 在分析ABD及TRIZ设计过程原理的基础上,提出将TRIZ解模型及相应的设计实例作为ABD的源设计,由类比设计过程确定目标设计及新设计的方法。造纸机改进设计实例说明了该方法的应用。     

Robust design optimization of nonlinear energy sink under random system parameters

Generally, in designing nonlinear energy sink (NES), only uncertainties in the ground motion parameters are considered and the unconditional expected mean of the performance metric is minimized. However, such an approach has two major limitations. First, ignoring the uncertainties in the system parameters can result in an inefficient design of the NES. Second, only minimizing the unconditional mean of the performance metric may result in large variance of the response because of the uncertainties in the system parameters. To address these issues, we focus on robust design optimization (RDO) of NES under uncertain system and hazard parameters. The RDO is solved as a bi-objective optimization problem where the mean and the standard deviation of the performance metric are simultaneously minimized. This bi-objective optimization problem has been converted into a single objective problem by using the weighted sum method. However, solving an RDO problem can be computationally expensive. We thus used a novel machine learning technique, referred to as the hybrid polynomial correlated function expansion (H-PCFE), for solving the RDO problem in an efficient manner. Moreover, we adopt an adaptive framework where H-PCFE models trained at previous iterations are reused and hence, the computational cost is less. We illustrate that H-PCFE is computationally efficient and accurate as compared to other similar methods available in the literature. A numerical study showcasing the importance of incorporating the uncertain system parameters into the optimization procedure is shown. Using the same example, we also illustrate the importance of solving an RDO problem for NES design. Overall, considering the uncertainties in the parameters have resulted in a more efficient design. Determining NES parameters by solving an RDO problem results in a less sensitive design.     

机构设计中的空间分离方法

针对应用发明问题解决理论中的4个分离原理解决物理冲突需依靠工程技术人员经验的现状,介绍了应用空间分离原理解决技术系统物理冲突的步骤及其创新原理,并根据概念设计框架阐述了机构设计应用空间分离原理的条件,指出机构设计空间分离原理的应用条件是需求域针对功能域的实现具有相互独立的伴随性物理冲突.根据水射流喷丸强化装卡试验装置设计实例,由其设计需求定义物理冲突,确定作用力为冲突参数,作用力需求满足应用空间分离原理的条件而选择空间分离原理,按照空间分离原理解决物理冲突的步骤进行了非交叉空间的选择,应用空间分离原理的10个创新原理中的抽取原理,形成了该装置的创新方案.机构设计中应用空间分离原理解决物理冲突的条件、步骤及其创新原理构成了机构设计空间分离方法,通过水射流喷丸强化装卡试验装置设计创新方案的提出证明了机构设计空间分离方法的有效性.     

A novel surrogate-based approach for optimal design of electromagnetic-based circuits

A new geometric design centring approach for optimal design of central processing unit-intensive electromagnetic (EM)-based circuits is introduced. The approach uses norms related to the probability distribution of the circuit parameters to find distances from a point to the feasible region boundaries by solving nonlinear optimization problems. Based on these normed distances, the design centring problem is formulated as a max–min optimization problem. A convergent iterative boundary search technique is exploited to find the normed distances. To alleviate the computation cost associated with the EM-based circuits design cycle, space-mapping (SM) surrogates are used to create a sequence of iteratively updated feasible region approximations. In each SM feasible region approximation, the centring process using normed distances is implemented, leading to a better centre point. The process is repeated until a final design centre is attained. Practical examples are given to show the effectiveness of the new design centring method for EM-based circuits.     

基于ARIZ的行李自助存取装置设计研究

目的 针对公共场所的行李自助存取装置进行研究再设计,通过ARIZ算法在设计程序中的应用,提供一种新的设计思路,实现产品设计的最优化。方法 根据ARIZ从问题分析到方案优选的系统性问题思考方法及其解决流程,针对已有行李自助存取装置出现的问题,运用ARIZ的问题解决流程进行设计构思与设计优化,完成行李自助存取装置的设计实践,验证ARIZ在设计中的时效性和功效性,探讨公共场所的自助服务设施设计创新方法。结论 ARIZ方法流程可以有效应用于设计中,为设计提供理论依据,并为行李自助存取装置创新设计提供详细的方案解析,将人机工学、绿色设计、智能技术等应用于设计中,提升了装置的综合性能和市场竞争力,为自助服务设施的设计应用提供了一种新的参考依据。     

A MODIFIED PATTERN SEARCH METHOD WITH RELAXED LEXICOGRAPHIC MINIMIZATION FOR ENGINEERING DESIGN

In engineering design, many design problems have multiple constraints and objectives, which may be non-differentiable. For this problem type, only zero-order solution methods are applicable. In this paper, a relaxed lexicographic pattern search method is presented for solving this design problem type, where the objectives are preferenced in either an Archimedean or preemptive formulation. The Hooke-Jeeves (HJ) pattern search method is the basis of this method, which is implemented as the MORPS (Multi-Objective Randomized Pattern Search) algorithm. The HJ pattern search method is used because it requires only function values and has an intuitive graphical interpretation through which to gain insight into the nature of complex design spaces. A relatively new class of simultaneous product/process design problem utilizing virtual prototypes to support design for disassembly is introduced to motivate the need for the MORPS algorithm. An example, based on the design of an automotive center console for disassembly, illustrates the application of the MORPS algorithm.     

A methodology for planning experiments in robust product and process design

Robust design is an important method for improving product manufacturability and life, and for increasing manufacturing process stability and yield. In 1980 Genichi Taguchi introduced his approach to using statistically planned experiments in robust product and process design to U.S. industry. Since then, the robust design problem and Taguchi's approach to solving it has received much attention from product designers, manufacturers, statisticians and quality professionals. Although most agree on the importance of the robust design problem, controversy over some of the specific methods used to solve the problem has made this an active research area. Although the answers are not all in yet, the importance of the problem has led to development of a four-step methodology for implementing robust design. The steps are (1) formulate the problem by stating objectives and then listing and classifying product or process variables, (2) plan an experiment to study these variables, (3) identify improved settings of controllable variables from the experiment's results and (4) confirm the improvement in a small follow-up experiment. This paper presents a methodology for the problem formulation and experiment planning steps. We give practical guidelines for making key decisions in these two steps, including choice of response characteristics, and specification of interactions and test levels for variables. We describe how orthogonal arrays and interaction graphs can be used to simplify the process of planning an experiment. We also compare the experiment planning strategies we are recommending to those of Taguchi and to more traditional approaches.     

Formalized specification of functional requirements

With the increasig use of the computer as a design aid, the need for new software products is increasing rapidly. Computer aids for the conceptual phase of the design process are now emerging. A basic problem in making design aids for this phase is to formulate the functional requirements in a way suitable for computer processing. In this paper, an approach to solving this task is presented. These functional requirements (FRs) are formulated as a set of verb-noun pairs. A thesaurus will define the set of verbs and nouns applicable in the definitions of the FRs and a synonym table will be available, to aid the user in finding appropriate words within the thesaurus. For further processing of the FRs a classification system for verbs and nouns is proposed. The classification is based on object oriented programming languages.     

External Support of Problem Analysis in Design Problem Solving

Design is described as creative design problem solving. The first step of the design process is to identify and analyze the design problem. This step has an important influence on the creation of an effective design solution. In two experiments, we tested the benefits that sketching provides during the analysis process in design problem solving. In particular, this paper focuses on the design process, the act of sketching, the sketch itself, and the final product. In prior studies, the process of sketching has been shown to enhance the construction of a mental representation, and thus the sketch has improved the analysis of the problem. The memory supporting effect of sketches is verified in the second experiment discussed in this paper. Finally, this paper also discusses the support possibilities the sketch offers for the early stages of the design process.     

Research on conceptual design of mechatronic systems

Based on the fact that function-structure generating and function solving are alternant processes with mutual causality during the conceptual design phase of mechatronic systems, a conceptual design cyclic feedback solving model of a mechatronic system is put forward on the basis of mapping between function layer, effect layer, working principle layer and structure layer. The process of solving single and system functions is analysed. Key technologies of interface matching and function solving are then advanced. Finally, a computer-aided conceptual design automatic software system for mechatronic systems is developed and the conceptual design of a computerised embroidery machine is given as an example. This work was supported by the National Natural Science Foundation of China (Grant No. 50375045) and the Shanxi Natural Science Foundation of China (Grant No. 20041070).     

The effects of experience during design problem solving

Behavioural and physiological experiments to analsye the development, influence and application of experience during design problem solving are described. The results of the behavioural experiments show, that while novices try to solve assignments through deductive reasoning, experts prefer to apply their experience directly. The electrophysiological experiments indicate, that as a manifestation of this, the regions activated in the human brain during problem solving vary according to the experience a test person has. Novices show a longer activity in the frontal regions whereas the experts seem to have longer activity in the parietal regions of the brain.     

Drawings and the design process: A review of protocol studies in design and other disciplines and related research in cognitive psychology

A characteristic of the design process in all areas of design is the use of a number of different types of drawings. The different types of drawings are associated with different stages of the process with one type, the relatively unstructured and ambiguous sketch, occurring early in the process. Designers place great emphasis on the sketch often because it is thought to be associated with innovation and creativity. Because of this emphasis researchers have also begun to focus on the sketch and its role in design. The first aim of this paper is to collect together and review the results of this research and to relate it to similar research that has looked at the role of drawings in problem solving in other disciplines. Recently, however, researchers in the design area have begun to relate their work to a number of areas of research in cognitive psychology and cognitive science. This work provides theoretical frameworks, experimental methodologies and a considerable body of research results that are of great potential importance to design research. The second aim of this paper is to review three of these areas, working memory, imagery reinterpretation and mental synthesis, and to examine their implications for design research generally but with a particular emphasis on the role of sketching in design.     

Cognitive basis for conceptual design

Engineering design is a highly iterative process. Nevertheless, the set of solution principles obtained during the conceptual phase seems to establish the universe of discourse for that design task. The richness, fertility, and completeness of this set of solution principles critically affects the character of the design to be. This seed pool of ideas seems to shower only the gifted designers and problem solvers. The moment of creation, the breakthrough, always has an aura of mystery surrounding it. However, it is important that this process be studied empirically. This article presents an operational model of the cognitive processes at the breakthrough stage of conceptual design. The model is then used to analyze some illustrative examples. We believe that this initial operational glimpse into how ideas happen will help designers confront unsolved problems. This operational view of the creative process may also influence how designers will be trained in problem solving.     

基于新能源燃料特性的辅助发电动力设备设计研究

目的 为缓解能源短缺与环境污染双重危机,设计一款基于植物油基微乳化燃料、适合多场景应用的辅助发电动力设备。方法 通过热力学燃烧定律与能量转换定律分析植物油基微乳化燃料的发动机台架试验数据,并总结其燃烧特性与潜在问题;针对上述特性与问题设计一款可有效将该燃料化学能转化为机械能的辅助发电动力设备。结果 植物油基微乳化燃料的“微爆效应”与燃烧过程中分解自身氧的特性都对燃烧过程具有促进效果,作为替代燃料可行性较强,针对其冷启动困难、易积碳等问题,可通过设置提前预热结构优化其喷雾质量,达到从结构上解决上述问题并能有效提供动力的目的,将其与发电机结合形成的生态发电系统能够解决野外露营、工厂停电等特殊情况下的短期供电问题。结论 在保证动力输出与生态性的前提下提出的动力设备设计方法,有针对性地解决了植物油基微乳化燃料在应用过程中所出现的问题,也为特殊情况下解决短期供电问题提供了有效参考。