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).     

Guiding functional design of mechanical products through rule-based causal behavioural reasoning

The paper presents a behaviour-driven functional (B-FES) modelling framework for functional design of mechanical products based on a rule-based causal behavioural reasoning step to guide the design process. A new representation scheme called rule-based behavioural representation (causal behavioural rules) was developed to facilitate causal behavioural reasoning, with which the interconnected physical behaviours can be reasoned out from a desired function. The behaviour schema was then used to select and arrange embodiments (abstractions of physical artefacts) to develop a set of potential concept variants. The proposed approach was not only useful in the creation of new configurations (combinations) from a library of standard physical behaviours, but also it might be used to generate specifications of new physical behaviours. A design case study of a terminal feeding unit is presented to demonstrate the practicality of the proposed approach.     

The habitability framework: a conceptual approach towards linking human behaviour and physical environment

This paper presents the background, rationale and elements of the habitability framework which links human behaviour to aspects of the physical environment. The conceptual framework is accompanied by examples of applications, including behaviour-based facility programming and post-occupancy evaluation.     

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.     

Critical scenarios derivation methodology for mechatronic systems

This paper deals with safety in design of mechatronic systems. We propose a method based on a qualitative analysis of a Petri net model of the system. It allows deriving feared scenarios by determining the sequences of actions and state changes leading to the feared state in which the passenger's safety is no longer guaranteed. The Petri net model of the system takes into account normal behaviour, failures and reconfiguration mechanisms. Our approach uses linear logic as formal framework and is based on a backward and a forward reasoning. It derives feared scenarios as causal relationships between normal states and the feared one.     

A hybrid methodology for enhancing reliability of large systems in conceptual design and its application to the design of a multiphase flow station

This paper presents a hybrid methodology for conceptual design of large systems with the goal of enhancing system reliability. It integrates the features of several design methodologies and maintenance planning concepts with the traditional reliability analysis. The methodology considers the temporal quality characteristic “reliability” as the main objective and determines the optimal system design. Key ideas from several design methodologies, namely axiomatic design, robust design, and the theory of inventive problem solving, have been integrated with the functional prioritization framework provided by reliability-centered maintenance. A case study of the conceptual design of a multiphase pumping station for crude oil production is presented. The methodology provides a new design tool for determining system configurations with enhanced reliability taking into account maintenance resources and variability.     

A constraint‐based approach to the modelling and analysis of packaging machinery

To enable packaging machinery manufacturers to compete at an international level, it is necessary to introduce them to more advanced design methods and technologies. For years, the evolution of packaging machinery has relied heavily on trial‐and‐error methods. The demands for continual increases in the performance capabilities of the machines, escalating legislation, environmental directives and changes in the characteristics of the product require rapid development of existing machine designs and the creation of new machines. This paper discusses the needs of SME packaging machinery manufacturers and identifies their requirements for methods in support of the design and redesign of packaging machinery. The need to identify, capture and manipulate design knowledge is critical for SMEs, where all too often design records are incomplete. Furthermore, a systems modelling approach that provides for support over the conceptual, embodiment and detailed design phases is essential for the rapid and effective development of designs. In order to meet these requirements, a methodology is proposed which incorporates ‘constraint modelling’ techniques. The methodology provides for experimental investigation and computer‐based modelling, which together aid the designer in gaining a fundamental understanding of the design problem. This enables the identification and representation of design knowledge, the determination of the limitations of an existing design, the evaluation of alternative designs and redesign strategies, as well as the embodiment, refinement and optimization of design solutions. The theory of ‘constraint modelling’ is discussed and the various phases of the methodology described. The applications of the methodology to a new machine design and a redesign program are also detailed. Copyright © 2001 John Wiley & Sons, Ltd.     

Multi-criteria fuzzy decision support for conceptual evaluation in design of mechatronic systems: a quadrotor design case study

Designing mechatronic systems is known to be a very complex and tedious process due to the high number of system components, their multi-physical aspects, the couplings between the different domains involved in the product, and the interacting design objectives. This inherent complexity calls for the crucial need of a systematic and multi-objective design thinking methodology to replace the often-used sequential design approach that tends to deal with the different domains and their corresponding design objectives separately leading to functional but not necessarily optimal designs. Thus, a new approach based on a multi-criteria profile for mechatronic systems is presented in this paper for the conceptual design stage. Additionally, to facilitate fitting the intuitive requirements for decision-making in the presence of interacting criteria, three different methods are proposed and compared using a case study of designing a vision-guided quadrotor drone system. These methods benefit from three different aggregation techniques such as Choquet integral, Sugeno integral and fuzzy-based neural network. To validate the decision yielded by the results of global concept score for each aggregation methods, a computer simulation of a visual servoing system on all design alternatives for quadrotor drone has been performed. It is shown that although the Sugeno fuzzy can be a useful aggregation function for decisions under uncertainty, but the approaches using Choquet fuzzy and fuzzy integral-based neural network seem to be more precise and reliable in a multi-criteria design problem where interaction between the objectives cannot be overlooked.     

Understanding affect in design: an outline conceptual framework

This paper provides an outline conceptual framework that may be helpful for those involved in the emerging area of ‘affective design’. Historically, the shift from cognitive approaches that eschewed emotions towards a more encompassing conceptual approach that includes affective or emotive processes is understandable. A basic understanding of concepts such as affect and emotion are required in order to address many questions such as how to design to evoke affect and how to predict user emotions? We utilize concepts from Activity Theory in order to understand the world of ‘feelings’. The latter involves several different levels and classes, principally those of affect, emotion and sentiment. Feelings involve important psychological processes, although they have received minimal attention within the mainstream cognitive frame until very recently. The intent of this paper is to provide a coherent conceptual frame for the discussions within the interaction design and HCI communities concerning such terms as emotional interfaces, hedonic design and affective design.     

A Petri net based design engine for manufacturing systems

Support for the efficient design and operation of complex manufacturing systems requires an integrated modelling, analysis, and control methodology as well as its implementation in a software tool. In this paper the Petri net based design engine TimeNET is presented for this task. Petri nets are able to capture the characteristic features of manufacturing systems in a concise form. A subclass of coloured Petri nets is used, which has been developed especially for the application area of manufacturing. Structure and work plans are modelled separately. Stochastic as well as deterministic and more general distributions are adopted for the firing times of transitions. Fundamental questions about system properties can be answered using qualitative analysis. For an efficient performance and dependability prediction, different evaluation techniques are proposed: direct numerical analysis, approximate analysis, and simulation. Finally, the model can be used to evaluate different control strategies and to control the manufacturing system directly. There is no need to change the modelling methodology, thus avoiding additional effort, for example for model conversion. In the paper this necessary steps are described using an application example.     

Sensor-based stage Petri net modelling of PLC logic programs for discrete-event control design

Petri nets have been extensively applied for specification, design, verification, performance evaluation, and simulation of discrete event control systems (DECS). The usual way to verify the dynamic behaviour of DECS design is to employ a process-based model, which proves to be impractical in application because the process-based model does not usually fully correspond to the control programming behaviour. This paper proposes a sensor-based stage Petri net (SBSPN) to represent a programmable logic controller (PLC) stage logic diagram (LD) for discrete-event control design. The new technique is able to simplify the modelling process of the complex PLC program without considering the interlocking problem within the ladder diagram. An illustrated example is used to explore the new methodology. The proposed method contains the power and flexibility of the Petri net analysis prior to the PLC implementation. It is believed that this technique is significant for industry practice.     

Visual interactive simulation and artificial intelligence in design of flexible manufacturing systems

The design of flexible manufacturing systems is a complex decision-making process that typically involves the evaluation of a number of different design alternatives. The evaluation is often performed using modelling and simulation techniques. The role of visual interactive modelling and simulation in design of flexible manufacturing systems is discussed. The application of artificial intelligence techniques to implement a set of knowledge sources, used for accomplishment of various design activities, is described. An object-orientated implementation is used to illustrate the underlying concepts.     

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.     

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.     

A Petri net approach to behavioural simulation of design artefacts with application to mechatronic design

A Petri net-based design inference network (PNDN) architecture is presented in this paper. The network models the logical behaviour of any design artefact developed by designers at the conceptual design level by representing the subfunctions and their inter-relationships to perform a required overall function. The theoretical framework in developing the PNDN is based on the improved theory of Petri nets and hybrid automata. The theoretical PNDN architecture was implemented in a C++ based software called the design network simulator (DNS). The logical behaviour of a design artefact is modelled through the token flow within the PNDN. The token flow model is developed both for deterministic and nondeterministic PNDN, which involves uncertainties. In this paper we present the mathematical formalism of the deterministic token flow through the PNDN. We also provide a conceptual design example in order to explain the application of our theoretical architecture for structuring the PNDN.     

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).     

Petri nets and genetic algorithms for complex manufacturing systems scheduling

In this paper we propose the GAPN (genetic algorithms and Petri nets) approach, which combines the modelling power of Petri nets with the optimisation capability of genetic algorithms (GAs) for manufacturing systems scheduling. This approach uses both Petri nets to formulate the scheduling problem and GAs for scheduling. Its primary advantage is its ability to model a wide variety of manufacturing systems with no modifications either in the net structure or in the chromosomal representation. In this paper we tested the performance on both classical scheduling problems and on a real life setting of a manufacturer of car seat covers. In particular, such a manufacturing system involves features such as complex project-like routings, assembly operations, and workstations with unrelated parallel machines. The implementation of the algorithm at the company is also discussed. Experiments show the validity of the proposed approach.     

实体交互设计的发展历程及概念辨析

目的 针对实体交互设计及其相关概念混沌模糊的现象,梳理和总结实体交互设计的发展历程,讨论和界定实体交互设计的概念,分析实体交互设计的概念发展关系。方法 通过文献研究,梳理和总结实体交互研究方向的起源和发展,实体交互理论模型,特定领域的实体交互设计研究和实现技术,界定实体交互设计的概念及其基本关系。以Hornecker的实体交互框架为原型建立交互要素分析模型,对实体交互设计概念进行交互要素相关性分析,通过对比分析得出实体交互设计概念发展关系。结果 界定实体交互设计的概念和其基本关系,得出基于要素相关性的实体交互设计概念发展关系。结论 实体交互设计的发展历程大致分三个阶段,分别是物理性输入萌发、物理-数字耦合发展和体验导向的转变。可抓取交互界面、实体交互界面和RadicalAtoms概念都隶属于实体交互设计。实体交互设计与交互要素的发展相互促进,从以物理性要素为核心到通过技术加强表现性的实体交互界面,再到以物理性和表现性为基础、具备空间性和具身性的实体交互系统,体现了以体验为导向的实体交互设计发展历程。     

Development and characterisation of error functions in design

As simulation is increasingly used in product development, there is a need to better characterise the errors inherent in simulation techniques by comparing such techniques with evidence from experiment, test and in-service. This is necessary to allow judgement of the adequacy of simulations in place of physical tests and to identify situations where further data collection and experimentation need to be expended. This paper discusses a framework for uncertainty characterisation based on the management of design knowledge leading to the development and characterisation of error functions. A classification is devised in the framework to identify the most appropriate method for the representation of error, including probability theory, interval analysis and Fuzzy set theory. The development is demonstrated with two case studies to justify rationale of the framework. Such formal knowledge management of design simulation processes can facilitate utilisation of cumulated design knowledge as companies migrate from testing to simulation-based design.