G. Maarten Bonnema

Use of models in conceptual design

This article investigates the use of product models by conceptual designers. After a short introduction, abstraction applied in conceptual design is described. A model that places conceptual design in a three-dimensional space is used. Applications of conceptual design from the literature are used to identify several product models used by conceptual designers to handle the complex problems. Next, the models available in four conceptual design support tools are listed. In order to investigate the current use of models by conceptual designers, a questionnaire has been designed and issued. The design and results of this questionnaire are described and analysed. The results have been discussed with conceptual designers. It is concluded that several types of models are needed for conceptual designers to cope with and structure the large amount of information. In particular, budgets are used in the very early stages of the design process. Following that, mathematical models, physical models, block diagrams, specifications, and sketches are used. computer-aided design tools are used to implement the design. Finally, steps for further research are given.This article investigates the use of product models by conceptual designers. After a short introduction, abstraction applied in conceptual design is described. A model that places conceptual design in a three-dimensional space is used. Applications of conceptual design from the literature are used to identify several product models used by conceptual designers to handle the complex problems. Next, the models available in four conceptual design support tools are listed. In order to investigate the current use of models by conceptual designers, a questionnaire has been designed and issued. The design and results of this questionnaire are described and analysed. The results have been discussed with conceptual designers. It is concluded that several types of models are needed for conceptual designers to cope with and structure the large amount of information. In particular, budgets are used in the very early stages of the design process. Following that, mathematical models, physical models, block diagrams, specifications, and sketches are used. computer-aided design tools are used to implement the design. Finally, steps for further research are given.

Insight, innovation, and the big picture in system design

Systems architecting is the design phase where the top-level functions and performance of a system are distributed over the systems parts, its environment, and its users. Up till now, system architects had to largely learn the required skills in practice. Some courses exist that teach the right attitude and mindset for the system architect. However, methods for architecting that can be implemented in a computer tool are virtually nonexistent. Earlier we presented a method, FunKey Architecting, which may aid the system architect in the early phase of design. In combination with TRIZ a design tool is created, which can be used to simplify and improve system architectures. It aims at supporting both the system designer and the specialist designers working on systems. The main topic of the paper is the application of the method in two industrial cases. The one case is an environment where new technology has to be developed and state of the art physics have to meet machine construction principles. The other case is in an industry where well-proven technology is used in such a way that high-performance machines are created. A third application of the FunKey tool is performed by students at the University of Twente. The context of each case and the results will be described.

MULTI DOMAIN DESIGN: INTEGRATION AND REUSE

Design of mechatronic systems is becoming increasingly complex. Companies must continuously reduce time-to-market while increasing the quality, diversity, and functionality of their products. As a result, more and more specialists from various domains are needed to develop such products. To reduce time-to-market, many companies look to reducing the time it takes to design a product. Many focus on the reuse of design objects, leading to libraries of templates and standard components to speed up their design process. However, these reusable design objects are developed and maintained in the specialists’ domains, resulting in communication and integration issues between these domains. This paper discusses these issues and proposes a combined approach for model reuse, design integration, and communication between the designers, design tools, and models involved. A case study at a multi-national company successfully demonstrated that the approach leads to a faster and more consistent design process.

Early Insight in Systems Design through Modeling and Simulation

In early design stages, system architects mostly rely on estimations to make design decisions. These are based on the available information at hand and their experience. Modeling and simulation is almost exclusively applied in more detailed stages of design. In this paper we present an approach aimed at making better informed design decisions, early in the design process. Our approach focuses on giving insights in early design through simulations and models that are usually only provided in more detailed design stages. To do so, we propose a framework and address three conflicts that arise when connecting techniques from early and detailed design stages. These are dealing with uncertainty, accommodating multidisciplinary views and accounting for more divergent design space exploration strategies. The approach has been applied to a medical imaging system, to analyze a possible latency reduction. The goal of this case study was to gain realistic insight in system latency using a highly abstracted system model and a generic simulation model. Insights gained with these models confirmed that a new design reduces system latency and deals better with large variations in latency. The underlying structure of the approach has proven itself to be feasible. Further research is necessary to determine whether the approach can cover a broader range of applications and to evaluate how the full approach can be implemented

Requirements for high level models supporting design space exploration in model-based systems engineering

Most formal models are used in detailed design and focus on a single domain. Few effective approaches exist that can effectively tie these lower level models to a high level system model during design space exploration. This complicates the validation of high level system requirements during detailed design. In this paper, we define requirements for a high level model that is firstly driven by key systems engineering challenges present in industry and secondly connects to several formal and domain specific models used in model-based design. We analysed part of the systems engineering process at a company developing complex systems, by observing the design process and by analysing design documentation and development databases. By generalizing these observations, we identified several high level systems engineering challenges. They are compared to literature, focusing on reported systems engineering challenges and on existing approaches that incorporate high level models in model-based systems engineering. Finally, we argue that high level system models supporting design space exploration should be able to communicate information regarding design trade-offs (e.g. safety versus ease of use) effectively in a multidisciplinary setting. In our outlook, we propose how to continue our research, by recommending further research and defining a research question.

Capturing Design Process Information in Complex Product Development

From interviewing developers and analyzing examples from industry, the authors have concluded that communication issues during the design process are a key factor of the complexity of product development. These communication issues stem from a lack of insight in the workflow between designers and their resources, and the lack of insight in the relation of this workflow to the system architecture. To the best knowledge of the authors, currently there are no suitable models and tools that allow capturing and understanding such information in an integrated way. This work contributes by providing requirements for tools and models, and proposes a modeling language that fulfils such requirements. With this language we introduce a method for capturing design process information: The language can combine multiple stakeholder-based views on their system aspects of interest with architectural concerns, and can specify which resources in terms of models and parametric information are needed from other stakeholders to develop these aspects. The language was also developed as a stepping stone for automation of design processes

Cycling strategies of young and older cyclists

This study concentrates on the cycling strategies of older cyclists (54-62year olds) in comparison to young cyclists (20-30year olds). While cycling in a safe laboratory set-up, controlled lateral perturbations are applied to the rear of the bicycle. Three possible strategies to keep balance are analysed for a young and older aged group: steering, lateral trunk movement and outward knee movement. Older subjects appear to rely more on knee movement as a control mechanism than young subjects. Furthermore, the frequency domain analysis revealed that the older adults need more effort to counteract high frequency perturbations. Increased inter-individual variation for the older adults subject group suggests that this group can be seen as a transition group in terms of physical fitness. This explains their increased risk in single-sided bicycle accidents (i.e. accidents involving the cyclist only). Therefore, older cyclists could benefit from improving the stability of cycling at lower speeds.

Electric mobility and charging: Systems of systems and infrastructure systems

In light of European and worldwide environmental programs, reduction of CO2 emissions and improvements in air quality receive a lot of attention. A prominent way to improve on both aspects is the replacement of Internal Combustion Engine Vehicles with Electrical Vehicles. Yet, simply replacing vehicles will not result in proper electric mobility because using Electrical Vehicles depends on many systems and infrastructures including the chargers, parking sites and payment structures. In this paper we will take an explorative view on Electric Mobility and match developments in that area with Systems of Systems Engineering. We will also present a case study on charging many Electric Vehicles, where we will match business opportunities and technical feasibility to the transition from early adopters to the early majority as main Electric Vehicle users.

User-centred system design approach applied on a robotic flexible endoscope

Abstract Complex systems, like surgical robots, are designed by engineers. It is very difficult for them to determine the different needs and desires of all stakeholders. Especially when designed from scratch, end user input is essential in creating a system that has added value, is user friendly, and can be easily integrated into practice. For the development of a robotic flexible endoscope we have involved physicians, nurses, and equipment suppliers in our design approach. Seven steps are executed to convert user preferences and capabilities into concepts: • Determine focus area of development. • Create the current workflow of system application to understand (the context of) use. • Determine problem definition and design goal. • Create the future workflow, in which current problems are eliminated and major system wishes are fulfilled. • Translate the future workflow into a functional overview that contains system functions. • Select and configure the appropriate construction elements into physical overviews, being preliminary concepts. • Decompose physical overview into manageable modules. These views are evaluated by the major stakeholders and together form a system architecture. The system architecture helped us in defining the robotic modules required to fulfill all stakeholders‟ needs and desires. Demonstrators were built to evaluate critical concepts in clinical relevant experiments.

Conceptual design in a high-tech environment

This article will give an overview over design process models before concentrating on the main subject: Conceptual Design, which has had less academic attention than the detail design phases. In high-tech environments specific conditions apply. This article will deal with these conditions. Some views on design in general are treated and attention is paid to the conditions and steps and to the level of abstraction, goals, people and skills. The paper identifies the crucial role of the systems engineer in the conceptual design phase. The conceptual design tasks and their results will be treated. As the conceptual designer is best aware of the overall functionality of the system and the interrelations, he is able to safeguard the concepts in later design phases and to make a good decomposition into subsystems. The paper ends with conclusions and directions for Future Work.