Distributed product and facility prototyping in extended manufacturing enterprises

In order to reduce the cost at the early product development stages, the planners need methodologies and tools that would allow them to judge upon the implications of the product design on the required manufacturing processes and facilities for their production. This paper reports on a new theoretical platform and a pilot implementation of a decision-making environment for distributed product and facility prototyping in an extended enterprise. The approach is based on an exchange of requests and information between collaborative autonomous agents that support the design, manufacturing planning and facility formation activities. The decision-making is formalized as iterative matching of design, process and facility attributes using multilevel resource capability representation within the extended enterprise. The system is implemented as an XML/CORBA-based environment for conveying design and manufacture messages across traditional technology boundaries. The reported research aims to provide the designers with a rapid manufacturing feasibility assessment tool to be used at different design and planning stages in extended manufacturing enterprises.     

Multiobjective Decision Analysis for Acceptance Sampling Plans

In recent years there has been increased interest in the design and implementation of economically based sampling plans, especially those which consider a prior distribution of defectives in lots submitted for inspection. Sampling plans which are designed using this prior knowledge are often referred to as Bayesian sampling plans. This paper illustrates an approach to the design of Bayesian sampling plans which considers two criteria. The few previous attempts to design multiobjective Bayesian sampling plans have been based on expected values of the criteria. In this paper the authors present a design methodology which takes into consideration the distribution functions of the criteria after sampling inspection, and the utility function of the 'decision maker'. Illustrative examples of the use of the methodology are given as well as areas for further research.     

‘Signposting’, A Parameter-driven Task-based Model of the Design Process

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.     

Analysing context-dependent deviations in interacting with safety-critical systems

Mobile technology is penetrating many areas of human life. This implies that the context of use can vary in many respects. We present a method that aims to support designers in managing the complex design space when considering applications with varying contexts and help them to identify solutions that support users in performing their activities while preserving usability and safety. The method is a novel combination of an analysis of both potential deviations in task performance and most suitable information representations based on distributed cognition. The originality of the contribution is in providing a conceptual tool for better understanding the impact of context of use on user interaction in safety-critical domains. In order to present our approach we provide an example in which the implications of introducing new support through mobile devices in a safety-critical system are identified and analysed in terms of potential hazards.     

A comprehensive tool for developing new human-centred and social inclusion-oriented design strategies and guidelines

While Human-Centred Design is by the time considered a consolidated design methodology, emerging social inclusion-oriented theories need to be more comprehended in order to understand their potential applications in the development of new design solutions. This sort of discrepancy often generates contradictory phenomena: solutions developed using such approaches cannot be considered, at the same time, fully human-centred and social inclusion-oriented. The purpose of this article is to describe a new comprehensive tool, conceived both for designers and researchers, able to develop human-centred and social inclusion-oriented design strategies and guidelines. The tool, which is called ‘HSDT’ (Human-Social Design Tool), is an easy-to-use methodological instrument useful to identify focused results oriented toward Human-Centred Design and Social Inclusion. Using logical sequences, it allows to develop new conceptual definitions for both design and non-design subjects into new human-centred and social inclusion-oriented records. Theoretical foundations, methodological approaches, development stages and applications in design and non-design areas are presented and discussed to demonstrate real benefits resulting from the introduction of a new type of interdisciplinary tool and, later, the opportunity for designers and researchers to adopt new problem-solving approaches to bridging the gaps within Design literature.     

Information supported design for manufacture of injection-moulded rotational products

Whilst the concurrent engineering philosophy has been embraced by a wide range of engineering companies as a means to remaining competitive, the design software tools which are commercially available are limited in their ability to offer concurrent support. This paper describes research which has investigated how design for manufacture information can be provided back to designers as concurrently as possible. The paper, using injection moulding as its focus, illustrates how a design for manufacture environment can be structured to utilize company product and manufacturing information. In particular, the need for appropriate information translation mechanisms and design support strategies is described. An example, highlighting the potential of the approach and utilizing an experimental object-oriented system, is discussed.     

Design Support Using Distributed Web-Based AI Tools

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.     

Knowledge-based sequence planning of shearing operations in progressive dies

This paper aims to study the methodology of building the knowledge of planning adequate punches in order to complete the task of strip layout for shearing processes, using progressive dies. The usage of superimposition of punches for planning strip layout is widely accepted among progressive die designers; however the huge number of combinations of punches may turn this easy-to-understand process into a nightmare. The proposed methodology uses die design rules and characteristics of different types of punches to classify them into five groups: prior use (the punches must be used first), posterior use (must be used last), compatible use (may be used together), sequential use (certain punches must precede some others), and simultaneous use (must be used together). With these five groups of punches, the searching space of feasible designs will be greatly reduced, and superimposition becomes a more effective method of punch layout. The superimposition scheme may generate many feasible solutions. Although none of them really violates die design rules, some of them are just better than others. An evaluation function based on number of stages, moment balancing and strip stability is developed. For meeting different designers’ preferences, these three factors are coupled with various weightings, so, designers can fine tune and find better results. The whole process is not only to provide a new approach to solving the superimposition puzzles, but also to try to integrate the die design rules and designer's personal experience, which should be extremely helpful in speedier progressive die design.     

Workload prediction for improved design and reliability of complex systems

This paper describes a method and a tool for analysing and predicting workload for the design and reliability of complex socio-technical systems. It concentrates on the need to assess workload early in the design phase to prevent systems failures. This is a continuation of our previous work on workload assessment. The method is supported by a tool that enables scenario-based validation of prospective socio-technical systems designs such as command and control rooms of military vessels. The approach combines probabilistic measures of human performance with subjective estimates of workload. The causal relationships of performance shaping factors (PSF) are modelled in a Bayesian belief network (BBN) and used to assess the agent's operational performance and reliability. Workload for each agent is calculated based on demand placed upon agents in terms of behavioural response to tasks, communications and interactions between humans and technology. The approach uses scenarios to stress test prospective system designs, where each scenario is modelled as a sequence of events. Reliability is expressed in terms of human error and is dynamically assessed throughout test scenario executions using BBN technology. The innovation beyond traditional reliability analysis relies to the use of dynamic and static estimates of reliability inputs for better informed assessment. This method enables identification of performance bottlenecks to be addressed by the designer early in the design phase. A case study is presented that demonstrates the use of the method and tool for the design of the command and control room of a military vessel.     

Evolutionary engineering design synthesis of on-board traffic monitoring sensors

In this paper, a formal engineering design synthesis methodology based on evolutionary computation is presented, with special emphasis on the design and optimization of distributed independent systems. A case study concerned with design of a sensory system for traffic monitoring purposes is presented, along with simulations of traffic scenarios at several levels of abstraction. It is shown how the methodology introduced is able to deal with the engineering design challenges present in the case study, and effectively synthesize novel design solutions of good quality. Moreover, when the fitness function is formulated as an aggregation of design preferences with different weights and trade-off strategies, the complete Pareto optimal frontier can be determined by the evolutionary synthesis methodology. The results of this study suggest that the approach can be useful for designers to solve challenging engineering design synthesis problems.     

可拓方法与TRIZ方法在产品创新设计上的应用

由中国学者蔡文于1983年所创立的可拓学，发展迄今近20年以来，已经成功地应用在新产品构思、决策、搜索、诊断、识别与评判等各个专业领域，应用其方法可以解决工程上所面临的矛盾问题。而由前苏联学者Genrich．S．Altshuller于1946所发展之TRIZ(俄文英译：Theory of Invention Problelm Solving，TIPS)方法，是由两百万余项专利所推演、分析与归类之独到工程矛盾解决方法，对于创新设计工程问题有相当程度之助益。笔者主要研究两方法在产品创新设计之特性与差异，包含前者是以理论学说导向工程应用；后者是以实际结果统计归纳出解决途径等。此外，试图藉可拓方法中的物元变换方法，采用其解决矛盾问题的基本特性，结合TRIZ方法的矛盾矩阵，应用于产品创新改良设计，并得到可行结果。     

A Bayesian network approach for fixture fault diagnosis in launch of the assembly process

Verification and correction of faults related to tooling design and tooling installation are important in the auto body assembly process launch. This paper introduces a Bayesian network (BN) approach for quick detection and localisation of assembly fixture faults based on the complete measurement data set. Optimal sensor placement for effective diagnosis of multiple faults, structure learning of the Bayesian network and the diagnostic procedure are incorporated in the proposed approach. The effective independence sensor placement method is used to reach the desired number of optimal sensor locations, which provide the concise and effective sensor nodes to build the diagnostic Bayesian network. A new algorithm based on conditional mutual information tests is put forward to learn the Bayesian network structure. The body side assembly case was used to illustrate the suggested method and the simulation analysis was performed to evaluate the effectiveness of the diagnostic network. The work demonstrated that the proposed methodology composes a feasible and powerful tool for fixture fault diagnosis in launch of the assembly process.     

Stochastic analysis and robust optimization for a deck lid inner panel stamping

FE-simulation and optimization are widely used in the stamping process to improve design quality and shorten development cycle. However, the current simulation and optimization may lead to non-robust results due to not considering the variation of material and process parameters. In this study, a novel stochastic analysis and robust optimization approach is proposed to improve the stamping robustness, where the uncertainties are involved to reflect manufacturing reality. A meta-model based stochastic analysis method is developed, where FE-simulation, uniform design and response surface methodology (RSM) are used to construct meta-model, based on which Monte-Carlo simulation is performed to predict the influence of input parameters variation on the final product quality. By applying the stochastic analysis, uniform design and RSM, the mean and the standard deviation (SD) of product quality are calculated as functions of the controllable process parameters. The robust optimization model composed of mean and SD is constructed and solved, the result of which is compared with the deterministic one to show its advantages. It is demonstrated that the product quality variations are reduced significantly, and quality targets (reject rate) are achieved under the robust optimal solution. The developed approach offers rapid and reliable results for engineers to deal with potential stamping problems during the early phase of product and tooling design, saving more time and resources.     

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.     

Guidelines or aesthetics: design learning strategies

This paper presents, as a theoretical vehicle, a simple dichotomy based on the concepts of the guideline approach and the aesthethics approach to design education. The dichotomy is used to deepen the understanding of design work and as a way of relating the question of design learning strategy to the historical controversy between the ideals of the Romantic and the Enlightenment traditions. The paper argues that the education of designers can be interpreted and understood to be based on some presuppositions about the nature of design work. It is concluded that design education should have as its first goal, to help design students to develop an intellectual capacity and to support them with necessary theoretical tool to be able to reveal hidden preconceptions and assumptions about design practice.     

Fuzzy covariance control for a class of continuous perturbed nonlinear stochastic systems

Abstract

This paper addresses the analysis and design of a fuzzy controller for a class of continuous perturbed nonlinear stochastic systems. The nonlinear systems are modeled by the Takagi‐Sugeno (T‐S) fuzzy models. The conventional LMI‐based fuzzy control method is inconvenient for directly assigning the common positive definite covariance matrix. Hence, this paper tries to develop a useful methodology to allow designers to assign a common positive definite covariance matrix for the closed‐loop system. Applying the theory of covariance control, a fuzzy controller is developed to achieve the stable conditions for the assigned common positive definite covariance matrix. Finally, a numerical example is given to demonstrate the usefulness of the proposed approach.     

A review of the support tools for the process of assembly method selection and assembly planning

This paper reviews the substantial body of research into software and other tools to support the closely related methodologies of assembly system selection, design for assembly, and assembly planning. Reported research has led to the adoption of a number of tools in current use in manufacturing industry. Here, the scope of this research, and its practical applications, is considered with a view to identifying the application domain of each approach and support tool. The authors are led to the conclusion that there is a need for further research into a methodology for the initial selection of the assembly method (e.g. assembly line, fixed point assembly, etc), and that such a methodology should consider not only factors of product technology, but also the industrial environment where assembly is to take place. Further, a knowledge-based decision support tool could facilitate the application of this methodology, and expand decision support further into the selection of assembly planning methods for subsequent application.     

A methodology of integrating affective design with defining engineering specifications for product design

Affective design and the determination of engineering specifications are commonly conducted separately in early product design stage. Generally, designers and engineers are required to determine the settings of design attributes (for affective design) and engineering requirements (for engineering design), respectively, for new products. Some design attributes and some engineering requirements could be common. However, the settings of the design attributes and engineering requirements could be different because of the separation of the two processes. In previous studies, a methodology that considers the determination of the settings of the design attributes and engineering requirements simultaneously was not found. To bridge this gap, a methodology for considering affective design and the determination of engineering specifications of a new product simultaneously is proposed. The proposed methodology mainly involves generation of customer satisfaction models, formulation of a multi-objective optimisation model and its solving using a chaos-based NSGA-II. To illustrate and validate the proposed methodology, a case study of mobile phone design was conducted. A validation test was conducted and the test results showed that the customer satisfaction values obtained based on the proposed methodology were higher than those obtained based on the combined standalone quality function deployment and standalone affective design approach.