Computer tools for integrated conceptual design

This paper outlines the conceptual design process with reference to the integrated computer-aided design tool known as Schemebuilder, and the related work of the Lancaster University Engineering Design Centre. The aim of the Lancaster EDC is to provide highly integrated support for the rapid creation and evaluation of a wide range of outline design schemes. Particular attention is paid to the design of mechatronic systems and devices.     

A scheme for functional reasoning in conceptual design

An ideal functional reasoning environment should support designs of any nature, routine or innovative, at any level of detail, as well as through varying levels of detail. In this paper, three existing functional reasoning models are reviewed in this perspective. It has been found that none of these models support all of these requirements. It has been shown that a functional reasoning approach cannot guarantee the generation of solution concepts, which are combinations of known solutions, unless guided by the knowledge of existing solutions. A new model which can support design both across a level of detail and down through levels of detail has been proposed, which, using a divide and rule approach and using recursive problem redefinition while incorporating existing solutions, could support conceptual design. It is also shown that, although the generation of completely new solutions is not supported by the model, the model, when aided by a framework allowing a sustained progress of its knowledge base by transfer of knowledge from existing designs in the form of basic structures and rules of combination, could support generation of designs which otherwise would be considered unsupportable in a systematic way (innovative).     

A heuristic-based approach to conceptual design

In the inherently large space of design, explicating all possible concept variants—to avoid leaving out potential concepts—is astronomically costly, if at all possible. A strategy that can assist designers in exploring and ascertaining design solutions within this vast space is therefore crucial. This work adapts a general best first heuristic algorithm for applications on conceptual design problems. The algorithm is tailored to operate on a model of conceptual design postulated in this paper. The propositions are established by an ordered series of formal definitions and mathematical assertions, which characterizes the complete theoretical model. Via a simple design case study, this product conceptualization approach is demonstrated to strategically guide designers in the exploration of design concepts.     

机构特征挖掘与创新概念设计方法

传统机构设计方法过度仰赖设计者本身专业素养与创意构思,缺乏有系统地利用现有信息,基础回避设计层级中往往无法有效掌握技术的创意概念,导致陷入低阶设计修改的窠臼之中。若能运用专利分析挖掘出机构设计概念,从大量know-how的分析中获得功能设计的know-why,则能于专利中获取相关机构之设计精神。设计方法则导入系统化机构概念设计,提高设计层次,以挖掘出的大量信息为设计基础,汇整出机构设计规范,并将设计规范导入概念设计方法,获得可行机构设计。如此能充分运用现有机构获得创新机构设计,能更有效率且更能掌握机构设计内涵,对于设计者能有效地获得可行设计、避免设计产生雷同而浪费资源,并可缩短研发时程。     

Supporting conceptual design with multiple VR based interfaces

Conventional computer aided design (CAD) systems have not provided enough support for conceptual design partly due to the lack of natural and intuitive human-computer interaction. Currently emerging virtual reality (VR) based techniques offer new ways to overcome these obstacles. In this paper, new CAD user interfaces including two-handed operation, haptic interaction, stereoscopic display and auditory feedback are investigated. The contribution of this work is to develop a new direct, natural and intuitive interaction paradigm required to support conceptual design. This paradigm enables designers to take fuller advantage of their visual, auditory and tactile sensorial channels to create, view, touch, hold, manipulate and listen to computer-generated virtual models. This is done more easily and freely in a more realistic three-dimensional (3D) environment through convenient interface device operation. A new conceptual design system called the LUCID system that fully integrates and implements these VR-based innovative interfaces into one design application is presented. As an approach to the next generation of human-computer interfaces for use in the design activity, the LUCID system has shown particular human computer interface benefits to designers during conceptual design based on the outcome from the user evaluation test.     

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.     

A semi-analytic approach to robust design in the conceptual design phase

One of the most important contributions to quality engineering over the last decades is the concept of robust design and its accomplishment through the use of various experimental methods. However, the prerequisite for successful parameter design in terms of a robust solution principle is seldom discussed. Methods that explicitly aid robust design in the conceptual design phase exist but are few. This article forwards the suggestion to use the principles behind the error transmission formula as a semi-analytic method for evaluation of robustness of concept solutions, prior to entering Taguchi's parameter design stage.     

Supporting conceptual design with multiple VR based interfaces

Conventional computer aided design (CAD) systems have not provided enough support for conceptual design partly due to the lack of natural and intuitive human–computer interaction. Currently emerging virtual reality (VR) based techniques offer new ways to overcome these obstacles. In this paper, new CAD user interfaces including two-handed operation, haptic interaction, stereoscopic display and auditory feedback are investigated. The contribution of this work is to develop a new direct, natural and intuitive interaction paradigm required to support conceptual design. This paradigm enables designers to take fuller advantage of their visual, auditory and tactile sensorial channels to create, view, touch, hold, manipulate and listen to computer-generated virtual models. This is done more easily and freely in a more realistic three-dimensional (3D) environment through convenient interface device operation. A new conceptual design system called the LUCID system that fully integrates and implements these VR-based innovative interfaces into one design application is presented. As an approach to the next generation of human–computer interfaces for use in the design activity, the LUCID system has shown particular human computer interface benefits to designers during conceptual design based on the outcome from the user evaluation test.     

A multi-agent-based approach for conceptual design synthesis of multi-disciplinary systems

It is encouraged that designers should explore in wide multi-disciplinary solution spaces for finding novel and promising principle solutions to desired functions during conceptual design. However, due to lack of sufficient multi-disciplinary knowledge, it is often difficult for human designers to explore in wide multi-disciplinary solution spaces. Therefore, this paper proposes a multi-agent-based approach for assisting designers in achieving multi-disciplinary conceptual design synthesis. The roles of different kinds of designing agents are identified, and the collaborative mechanisms among these agents are also elaborated. The conceptual design test case of a solar toy demonstrates that the proposed multi-agent-based design synthesis approach, compared with our previous approach, can achieve higher efficiency and better robustness through collaborative conceptual design synthesis.     

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).     

A tool for the conceptual design of production and operations systems

This paper proposes a conceptual design tool, based upon inferential design theory. It has been specifically developed for the design of production and operations systems, but its use can be extended to other engineering areas, such as mechanical and structural systems. Inferential design theory and its foundation in the inferential theory of learning are briefly outlined. Both theories are based on the idea of using specialised knowledge operators in learning and design, termed knowledge transmutations and design knowledge transmutations respectively. The 24 transmutations existing in the two theories are outlined, and a further 12 design-specific transmutations are proposed. These have been developed as a result of our research. A conceptual design process is proposed, in which design knowledge transmutations are used. A software tool for design, CREDO, is also described and an example of its use in the generation of design concepts for an after-sales service facility is presented. The conclusions discuss the initial methodological experience of using CREDO to generate design concepts. They are based on the introductory use of CREDO at Technion in Israel for teaching purposes. Directions for further research are also provided.     

Feature-based integration of conceptual and detailed mould design

The plastic production industry has been growing rapidly in recent years, and injection mould, which is especially widely used in 4C (computer, communication, consumer electronics, and car) products, is the most popular in moulding plastic. The diverse requirements of customers and pressures of just-in-time production are big challenges in the injection mould industry. The advantages, that keep products’ quality and increase work efficiency, will decide a company's competitive capabilities. Therefore, this study proposes a feature-based integration of the conceptual and detailed mould design process within the computer-aided design (CAD) tool. It adopts a feature-oriented method and the dedicated application programming interface (API) to implement the features integration function of the conceptual and detailed mould design. Based on intellectualised, customised, and standardised procedures, not only does this prevent probable engineering mistakes and generate consistent web reports, but also transmits the intact feature information from conceptual to detailed mould design, thus shortening detailed mould design processes. In the case studies of this paper, using the feature-based navigating system can result in time savings up to 56% and 59%. The results show significant time savings over traditional mould design processes.     

飞机总体设计中的一种多目标鲁棒优化方法

 提出一种基于灵敏度的多目标鲁棒优化方法。针对各维设计变量存在扰动的情况，在原约束多目标优化模型上，附加偏差目标函数，并采用最差估计法对约束条件进行鲁棒可行性调整。采用全局敏度方程方法来计算目标函数和约束函数对设计变量的敏度，进而采用Pareto遗传算法搜索约束多目标优化问题的非劣解集，设计者可以根据不同的设计准则从中选择合适的设计点。将上述方法用于飞机总体参数优化设计，并与采用常规优化方法所得的优化结果进行了分析和比较。