共查询到20条相似文献,搜索用时 31 毫秒
1.
Design Support Using Distributed Web-Based AI Tools 总被引:3,自引:0,他引:3
Paul A. Rodgers Avon P. Huxor Nicholas H. M. Caldwell 《Research in Engineering Design》1999,11(1):31-44
Currently, designers are faced with searching through a ‘sea’ of on-line knowledge to support their decision making activities.
This paper describes WebCADET, which is a reimplementation of the stand-alone CADET – a Knowledge-Based System (KBS) for product
design evaluation. WebCADET aims to provide effective and efficient support for designers during their searches for design
knowledge. WebCADET uses the ‘AI as text’ approach, where KBSs can be seen as a medium to facilitate the communication of
design knowledge between designers. The development of WebCADET to include practical support via World Wide Web-based functionality,
which illustrates the potential of the ‘AI as text’ approach, is described in the paper. 相似文献
2.
Polymer processes are in general difficult to model, especially because of coupling between process conditions, polymeric
behaviors and geometries. Arising from high thermal gradients, non-Newtonian viscous behaviors and non-linear pressure effects,
polymer processing is not well described mathematically. A conceptual design methodology is proposed formally as a useful
tool for treating polymeric processes with multiple performance parameters on a structured design platform. Without resorting
to engineering models, this approach deals with the initial selection of process conditions within a three-stage framework:
(1) qualitative design; (2) process modeling; and (3) quantitative design. Based on subjective reasoning, this procedure makes
it possible to account for one’s prior experience, and incorporate it into the process development. The notion of conceptual
robutstness is introduced to ensure deesign quality in the early-stage process development. A case study of compression molding
is illustrated in a step-by-step manner. 相似文献
3.
Arrow's Theorem and Engineering Design Decision Making 总被引:2,自引:2,他引:0
This article establishes that Arrow”s General Possibility Theorem has only indirect application to engineering design. Arrow”s
Theorem states that there can be no consistent, equitable method for social choice. Many engineering design decisions are
based on the aggregation of preferences. The foundation of many engineering decision methods is the explicit comparison of
degrees of preference, a comparison that is not available in the social choice problem. This explicit comparison of preference
levels is coupled with the choice of an aggregation method, and some forms of aggregation may be inadequate or inappropriate
in engineering design. 相似文献
4.
During engineering processes, many kinds and amounts of information are used and produced. Such information is useful in successive
cases, and thus its reuse is desired. In this paper, information on attributes of the products is referred to as ‘product
information’, and information on the reasons for and/or history of a designer’s thought process is referred to as ‘process
information’. According to this classification, process information can be used for obtaining an explanation of product information.
The purpose of this work is to build a database, called an ‘engineering history base’, from which engineers can retrieve explanations
to enable the reuse of product information. In this paper, explanation from the ‘process’ viewpoint is thought to be important
in promoting the reuse of product information. There are two types of explanation for the process: teleological and causal.
However, until now, little attention has been paid to the causal explanation for the process. Thus, in this paper, an information
model which focuses on both types of explanation is proposed. The model is adopted for the engineering history base and a
prototype system is developed. The appropriateness of this model is discussed by analyzing the actual data in the development
of a color video printer. 相似文献
5.
Structure and Matrix Models for Tolerance Analysis from Configuration to Detail Design 总被引:8,自引:0,他引:8
A substantial amount of all quality problems that arise during assembly can be referred back to the geometrical design, and
especially the geometrical concept of the product, i.e. the way in which parts are designed and located with each other. Special
emphasis should thus be put on geometry design, especially during the early design phases, to try to find robust concepts
and avoid solutions that may cause down-stream production problems.
This paper presents a generic set of evaluation tools for robust geometry design encountering (i) potential tolerance chain
detection in configuration design, (ii) assembly robustness evaluation in concept design, and (iii) tolerance sensitivity
analysis in detail design. Special attention is given to the development of a new matrix-based evaluation tool for the configuration
design part. The tool presented is based on a new way of representing geometry variation constraints in an enhanced function-means
tree structure model. Different parts of the function-means tree that are of interest for analysis purposes are then extracted
and converted to matrix representation. The reason for doing this is that the structure model is most suitable for modeling,
but becomes unsuitable for analysis as the model complexity increases. For this latter purpose, the matrix representation
is far better. The use of the different tools is demonstrated in the design of a new vehicle front system for which the geometry
a priori
is unknown. 相似文献
6.
In this paper, a novel technique is presented to solve tolerance design problems. To achieve the desired performance tolerance,
the technique uses a subtle, but significant, change in the design: the addition of a tuning parameter in place of an increase
in component precision. Statistical models are used to develop a framework for the tuning parameter design method. Also developed
is a new, dimensionless design metric which ranks candidate tuning parameters. A step-by-step method is developed for the
application of tuning parameters using this metric. The step-by-step tuning parameter design method is applied to a heavy-duty
manual stapler as a clarifying example. 相似文献
7.
This paper, written in memory of Professor Wolfgang Beitz, discusses some of the influences of the work undertaken in Germany
on systematic engineering design. It highlights differences between the language regions, and gives examples of design research
and design education linked to Konstruktionslehre– the standard text on systematic engineering design for which Professor Beitz was most widely recognised outside Germany.
The paper finishes with a plea for a greater exchange of ideas. 相似文献
8.
This article describes an engineering process representation and modeling tool. The approach is especially suitable for describing
large-scale, mature design processes involving numerous tasks, some of which may be performed by automated computer agents.
The underlying representation is a graph of information-processing units with explicitly defined input and output feature
elements. We show that this representation is more complete than those used in previous process modeling approaches and overcomes
some of their limitations when dealing with design processes involving dependencies at multiple levels of detail. The representation
is combined with rules for automatically operating upon the graph to preserve consistency when traversing to higher or lower
levels of detail. 相似文献
9.
Computing the Information Content of Decoupled Designs 总被引:1,自引:1,他引:0
The information content of uncoupled designs can be computed by summing the information content associated with each functional
requirement. This paper proves that information cannot be summed for decoupled designs. To overcome this problem, this paper
presents two algorithms for computing information content of decoupled designs. One algorithm is applicable to any joint probability
density function for the design parameters; the second algorithm applies only to uniformly distributed design parameters.
The algorithm for uniform distributions is based on a recursive procedure for computing the volume of a convex polytope in
n
-dimensional real space, where
n
is the number of design parameters. An engineering application of the algorithms is presented. The example demonstrates that
summing information content can significantly over-estimate total information when compared to an algorithm that accounts
for correlation. The example also demonstrates that decoupled designs can have lower information content than uncoupled systems
with the same functional requirements and similar components. 相似文献
10.
To obtain a better understanding of how to make use of functional materials in engineering design, the design-related behaviors
of some of these materials have been analyzed and discussed with reference to a general design procedure model and the design
tools currently available. The functional materials subjected to this examination are shape memory alloys, piezoelectric materials
and magnetostrictive materials. The discussion has been carried out with a major focus on how benefits might be gained by
selecting the functional material and utilizing complementary design tools at an early stage of the design process. 相似文献
11.
Beth Adelson 《Research in Engineering Design》1999,11(3):133-144
This work applies a theory-based framework of collaborative negotiation to some of the disputes that regularly arise during
group design. Although the framework was developed to provide general support for group work, this paper focuses on its use
as a design tool. The framework, embodied in our system NegotiationLens, has four facets. It:
1. Provides a negotiation method intended to produce gain for all parties.
2. Provides an efficient process for conflict resolution.
3. Develops working alliances.
4. Lets parties decide quickly when they should go their separate ways.
The framework produces the above results by:
• Helping parties develop well-reasoned and clearly articulated points of view (Adelson and Jordan, 1991; Conklin and Yakemovic,
1991; Conklin and Begeman, 1988; MacLean
et al
., 1991).
• Creating a context of committment and respect.
• Moving negotiating parties away from an adversarial stance and into a collaboration.
• Allowing joint construction of solutions that are more beneficial than the unilateral solutions each party initially brought
to the table.
We present our framework for collaborative negotiation, describe NegotiationLens, and present two cases in which it was used.
We present a third case, a large design project with recurrent design conflicts, and argue how NegotiationLens could have
been of benefit there. 相似文献
12.
This paper addresses the need for computer support in aerospace design. A review of current design methodologies and computer
support tools is presented, and the need for further support is discussed, with particular reference to the early formative
stages of the design process. A parameter-based model of design is proposed, founded on the assumption that a design process
can be constructed from a predefined set of tasks. This is supported by knowledge of possible tasks in which the confidence
in key design parameters is used as a basis for identifying, or signposting, the next task. A prototype implementation of
the signposting model, for use in the design of helicopter rotor blades, is described and results from trials of the tool
are presented. Further areas of research are discussed. 相似文献
13.
Matthew I. Campbell Jonathan Cagan Kenneth Kotovsky 《Research in Engineering Design》1999,11(3):172-192
This paper provides an introduction to a new design methodology known as A-Design, which combines aspects of multi-objective
optimization, multi-agent systems, and automated design synthesis. The A-Design theory is founded on the notion that engineering
design occurs in interaction with an ever-changing environment, and therefore computer tools developed to aid in the design
process should be adaptive to these changes. In this paper, A-Design is introduced along with some simple test problems to
demonstrate the capabilities of different aspects of the theory. The theory of A-Design is then shown as the basis for a design
tool that adaptively creates electro-mechanical configuration designs for changing user preferences. 相似文献
14.
A study was conducted of what influenced solution search activity in three design organisations. The influences were analysed
in terms of how they affected search, whether their effect tended to be conservative or innovative, and the directness of
the evidence they provided. Overall, the environment was found to provide more innovative influences than conservative ones.
Innovative influences were mostly connected with the triggering of search activity, while conservative influences were mostly
linked with restricting the search space of potential solutions. Also, search candidates were often evaluated in terms of
their associations rather than their intrinsic merits, and ultimately this makes human judgment an essential component of
search and evaluation activity. Finally, the environment provides many ‘seeds’ for effects like design fixation and functional
fixedness but also provides strong incentives to positively avoid these effects. 相似文献
15.
Critical design decisions are commonly made throughout the product development process assuming known material and process
behavior. However, stochastic variation during manufacture can inadvertently result in inferior or unacceptable product performance
and reduced production yields. Stochastic simulations have been developed to estimate the end-use performance distribution
prior to the commitment of hard tooling. This article proposes a definition for integrated product and process robustness,
and extends existing stochastic methods to model the important role of the manufacturing flexibility in elimination of defects
and product optimization. The goal is to enable the designer to understand and account for not only the negative effects of
manufacturing variation, but also the positive impact of manufacturing flexibility wherein instantaneous corrections in the
manufacturing process can frequently improve the product quality and eliminate flaws in the product design. Then, a methodology
is introduced and contrasted with conventional development methods in the evaluation of best practices for development of
a molded plastic component. 相似文献
16.
A Mathematical Framework for the Key Characteristic Process 总被引:3,自引:0,他引:3
Anna C. Thornton 《Research in Engineering Design》1999,11(3):145-157
To maximize product quality, a product design team selects concepts and dimensions to minimize a product’s sensitivity to
variation. However, even for the most robust products, it is rarely possible to transition a product into production without
encountering any variation-related problems. In a complex product, it is not economically or logistically feasible to control
and/or monitor the thousands of tolerances specified in a product’s drawing set. To address this problem, many organizations
are using Key Characteristic (KCs) methods to identify where excess variation will most significantly affect product quality,
and what product features and tolerances require special attention from manufacturing. As simple as this principle seems,
most companies struggle to effectively implement KC methods because no quantitative methods to prioritize KCs exist. This
paper develops a mathematical definition of a KC based on a variation propagation model. In addition, it develops a quantitative
effectiveness measure used to prioritize where verification, variation reduction, and on-going monitoring should be applied.
The effectiveness measure incorporates the cost of control, the benefit of control, and the expected change in process capability.
The methods are illustrated using an automotive door assembly. 相似文献
17.
Graham Coates Robert Ian Whitfield Alex H. B. Duffy Bill Hills 《Research in Engineering Design》2000,12(2):73-89
This is the second of two papers surveying research in coordination approaches and systems. This paper is concerned with operational
coordination, which is aimed at coordinating activities such that the design process can be performed in a near optimal manner
with respect to time, and the allocation and utilisation of resources. Aspects of coordination categorised as operational
include resource management, scheduling and planning. The first of these two papers presents a review of coordination from
a strategic perspective, which is concerned with the decision management aspects of coordination. Greater emphasis is now
being placed on the significance of organising the design process as this affects time to market, product quality, cost, and
consequently product success. The aim of this paper is to present a fundamental review of operational coordination approaches
and systems. The 1990s has seen much progress being made towards a greater understanding and appreciation of coordination
in various disciplines through the development of a wide range of approaches and systems. However, there remains a requirement
to formally identify the key issues involved in coordination such that a widely accepted representation can be agreed upon.
Consequently, research should continue to be supported in the exploration for a unified approach to coordination which will
permit a broader and greater understanding of those aspects involved. 相似文献
18.
A Theory of Complexity, Periodicity and the Design Axioms 总被引:2,自引:1,他引:1
Nam P. Suh 《Research in Engineering Design》1999,11(2):116-132
One of the topics that has received the attention of mathematicians, scientists and engineers is the notion of complexity.
The subject is still being debated, as it lacks a common definition of complexity, concrete theories that can predict complex
phenomena, and the mathematical tools that can deal with problems involving complexity. In axiomatic design, complexity is
defined only when specific functional requirements or the exact nature of the query are defined. Complexity is defined as
a measure of uncertainty in achieving a set of specific functions or functional requirements. Complexity is related to information,
which is defined in terms of the probability of success of achieving the Functional Requirements (FRs). There are two classes
of complexity: time-dependent complexity and time-independent complexity. There are two orthogonal components of time-independent
complexity, i.e., real complexity and imaginary complexity. The vector sum is called absolute complexity. Real complexity of coupled design is larger than that of uncoupled or decoupled designs. Imaginary complexity can be reduced
when the design matrix is known. As an example of time-independent imaginary complexity, the design of a printing machine
based on xerography is discussed. There are two kinds of time-dependent real complexity: time-dependent combinatorial complexity and time-dependent periodic complexity. Using a robot-scheduling problem as an example, it is shown that a coupled design with a combinatorial complexity can be
reduced to a decoupled design with periodic complexity. The introduction of periodicity simplifies the design by making it
deterministic, which requires much less information. Whenever a combinatorial complexity is converted to a periodic complexity,
complexity and uncertainty is reduced and design simplified. 相似文献
19.
Building Agility for Developing Agile Design Information Systems 总被引:1,自引:0,他引:1
Yoram Reich Suresh Konda Eswaran Subrahmanian Douglas Cunningham Allen Dutoit Robert Patrick Mark Thomas Arthur W. Westerberg 《Research in Engineering Design》1999,11(2):67-83
Agile manufacturing relies heavily on the quality of information that organizations have and on their ability to organize
and reuse it. Constant inflow of information and knowledge is the fuel of agile manufacturing. In the process of forming virtual
enterprises, these new organizations have to be equipped with information systems that integrate their present legacy technology
and improve upon it. To support the quick formation of virtual organizations, one must have the ability to develop such systems
quickly. Over the past few years we have evolved, through collaborative projects with industry, an approach composed of methods
and an information infrastructure called
n-dim that improves the ability of becoming agile manufacturers of information systems, by responding quickly to information needs
of new and evolving organizations. Following an analysis of the requirements of information systems for agile design, we discuss
this approach; describe some of the infrastructure features; and present several examples of simple applications that illustrate
them. We summarize by discussing the advantages and limitations of our approach. 相似文献
20.
Improving Systems by Combining Axiomatic Design, Quality Control Tools and Designed Experiments 总被引:2,自引:0,他引:2
Fredrik Engelhardt 《Research in Engineering Design》2000,12(4):204-219
This paper presents an approach for solving design problems in existing designs. A design analysis with Axiomatic Design,
called Design Object Analysis, describes a product or a system in terms of Customer Needs (CNs), Functional Requirements (FRs),
Design Parameters (DPs) and Process Variables (PVs), as well as their associated Design Matrices (DMs). In this paper, the
design analysis is combined with a thorough investigation of possible problems within the design, utilizing the seven quality
tools, noise factor analysis, and designed experiments to form an approach for quality improvements and problem solving. The
Design Object Analysis helps secure valid input-factors to the designed experiments, and the designed experiments correct
or improve the assumptions made in the Design Object Analysis. Thus, a combination of product modeling by Axiomatic Design
and designed experiments overcomes shortcomings of the two methods. The benefits of performing a Design Object Analysis, as
compared to other methods, become clear when it comes to evaluating the results from the designed experiment, and preventing the problem. Once the critical parameters are confirmed, and the design matrices are updated, suggested design improvements
can then be checked against the design matrices, and the system effect of a design-change-order can be estimated. The approach
described in this paper was successfully applied and verified in a case study at a large automotive company. 相似文献