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.     

A polychromatic sets approach to the conceptual design of machine tools

Currently very few computer-aided conceptual design systems are available to support the initial development of a machine tool and its structure (concept, calculation, design) and the verification of the prototype. In recent years, polychromatic sets have emerged as a promising approach for mathematical modelling. The theory, techniques, and approaches of polychromatic sets are capable of playing an important role in the conceptual design of a variety of products including machine tools. In this paper, the concept of polychromatic sets is introduced, and a polychromatic sets approach for the conceptual design of machine tools is proposed. The usefulness of the proposed method is illustrated by a conceptual design example of a machining centre of drilling, milling, and boring. Applying the proposed approach to machine tools helps to make right decisions in the conceptual design stage. Due to its powerful mathematical modelling capability, the polychromatic sets technique proposed in this paper may possibly be extended and applied to design evaluation problems encountered in other design tasks in manufacturing systems including process planning.     

Automatic conceptual design using experience-derived heuristics

Conceptual design is considered to be the most difficult phase of engineering design, with success dependent to a great extent on the expertise of the designer. Automation of some aspects of this phase would be of immense practical benefit. It is suggested that the generation of design solutions can be brought about through the application of heuristic knowledge. However, this sort of knowledge is in short supply and has proven difficult to acquire for computer systems. Nevertheless, actual examples of designers' work are more readily available, and the heuristics applied by designers may be considered to be implicit in these examples. The technique of Case-Informed Reasoning has been developed to try to exploit this potential source of knowledge, and applied to the task of fluid power circuit design, a configuration design task. This technique offers a practical approach to conceptual design automation in domains where design knowledge is lacking.

A conceptual framework for combining artificial intelligence and optimization in engineering design

Research in artificial intelligence and optimization (OR) has had significant impact on the formulation and solution of computational methods in engineering design. This paper presents a conceptual framework for understanding a more powerful technology that is evolving from a combination of these approaches. The paper first proposes generalized representations of engineering design models that involve quantitative and qualitative aspects. Second, it presents a general classification of AI and OR models in terms of model attributes, in order to establish mappings with generic solution techniques. Third, the requirements of solution methods are discussed, as well as several schemes for the integration of AI and optimization to identify future research directions. Several specific approaches are included to illustrate various ways in which AI and optimization can be combined for tackling computational design models.     

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.     

A network approach to parametric design integration

This article presents a method for the integration of multiple computing processes used in design and design assessment for a parametric design problem. The method is based on a representation in which the processes are regarded as performing transformations between model states representing attributes of the designed artefact. A classification of attributes and of transformations is presented. The sequences of transformations and model states are modelled using Petri nets, and these models are used as a basis for the development of a computer-based controller that manages the interprocess interaction. The controller directs the concurrent and sequential operation of a number of computing processes operating on different workstations in a network. These processes include geometric modelling and a variety of design analysis actions that exchange data with each other in the optimum design of parametric parts. The example of an automotive crankshaft design is given.     

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).     

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 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.     

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.     

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。     

Representation of function-form relationship for the conceptual design of stamped metal parts

Design representation of parts during conceptual design stage has been a challenging task because of the incompleteness of the information available. Traditional geometric design requires too much information on the geometric attributes, and does not consider the functionality of the part any more than that provided by individual features. Functional design in the form of verb, noun representation does not have adequate correlation with the geometric design. In this article, we propose a new form of the design representation of parts during conceptual design. The representation is calledsketching abstraction. In this representation, the discretionary geometry of the part that has functional relevance is captured using functional features, while the non-discretionary geometry is represented using a linkage mechanism. The functional features are related to the part function using data structures calledfunction-form matrices. The sketching abstraction is annotated with a set of primitives, and a grammar has been developed that parses the sketch to extract a set of canonical relationships between the functional features. These relationships can be used to extract part designs that are functionally similar but geometrically dissimilar. The sketching abstraction has a relationship with the solid model of the part as well. Thus we attempt to bridge the gap between function and form representations and provide the designer with a tool that can be used for generating design alternatives. We illustrate the theory developed in the domain of stamped metal parts.     

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).     

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.     

An approach to functional synthesis of solutions in mechanical conceptual design. Part III: Spatial configuration

These three papers describe an approach to the synthesis of solutions to a class of mechanical design problems; these involve transmission and transformation of mechanical forces and motion, and can be described by a set of inputs and outputs. The approach involves(1) identifying a set of primary functional elements and rules of combining them, and(2) developing appropriate representations and reasoning procedures for synthesizing solution concepts using these elements and their combination rules; these synthesis procedures can produce an exhaustive set of solution concepts, in terms of their topological as well as spatial configurations, to a given design problem.This paper (Part III) describes a constraint propagation procedure which, using a knowledge base of spatial information about a set of primary functional elements, can produce possible spatial configurations of solution concepts generated in Part II.     

Extracting and re-using design patterns from genetic algorithms using case-based reasoning

This paper proposes a scheme in which case-based reasoning techniques are employed to extract design patterns from a genetic algorithm used to optimize combinational circuits at the gate level. The approach seems to be able to (implicitly) rediscover several of the traditional Boolean rules used for circuit simplification and it also (implicitly) finds new simplification rules. Also, the paper illustrates how the approach can be used to reduce convergence times of a genetic algorithm using previously found solutions as cases to solve similar problems.     

Conceptual design of industrial systems: an approach to support collaboration

The design of any industrial system is a complex problem where many domains are involved. Each domain developed its own way of modeling based on a mono disciplinary perception. This leads to a communication problem and consequently to expectations on the formulated solution that do not correspond with the real solution. To enable the communication between domains and to preserve the match between intentions, expectations and reality of the system to be designed, a combination of a soft and hard systems approach is used to define a Conceptual model for Industrial Systems (CIS). The use of the model during design is illustrated for the technical domain, but has proven to be applicable for the organization and information domain as well.