Search

This paper presents results of transdisciplinary research on the development of a bioinspired computational framework for engineering design. This framework is intended to support design by addressing three critical design objectives, including novelty, optimality, and robustness. It provides several computational models and methods, which are inspired by fundamental processes occurring in nature, and discusses their potential for enhancing design. They include models and methods for evolutionary, developmental, and coevolutionary design. Their use is illustrated with examples from the area of steel structural design ranging from a simple cantilever beam design problem to a much more complex problem of designing wind bracings in tall buildings. The paper also shows how several methods and models can be integrated and form a coherent bioinspired computational framework for engineering design. [ABSTRACT FROM AUTHOR]

Design is the foremost step in the development of any electro-mechanical product. One limitation of existing design tools is that they only focus either on the initial design phase such as customer needs gathering, or on the later phases such as design embodiment or detailed design phase. As a result, there are very few existing computational tools to aid the designers at the conceptual design stage. The proposed research seeks to eliminate this drawback by providing a computerised conceptual design framework that incorporates Modularity, design for assembly (DFA) and design for variety (DFV) principles. Conceptual design alternatives obtained from the proposed research framework are ranked based on minimum assembly time, and are composed of modules in such a way that future changes in customer needs are satisfied only by replacing certain modules. This paper provides a detailed discussion of the proposed framework obtained by amalgamating Modularity, DFA, and DFV. Working of the framework is also demonstrated with the help of an electronic toothbrush design example. [ABSTRACT FROM AUTHOR]

Tolerance is almost ubiquitous during the whole product life. However how to effectively embody and interpret the semantics of tolerance in three-dimensional computer-aided design systems is still an open issue. Variational geometry is recognized as one of the most promising solution for it. And the methods for systematically and efficiently generating the variational geometries of all kinds of geometric entities with tolerances are imperative. In this paper, a degree-of-freedom (DOF)-based approach is proposed for generating variational geometry of a hole with composite tolerances imposed on its centerline and surface at the same time. All possible combinations of tolerance requirements for a hole are discussed. And the mathematical models for variational geometries of the centerline and the surface of a hole are deduced. Furthermore two strategies for improving the efficiency of generating the variational geometry of a hole are presented. Finally, the algorithm is implemented and some test results are given. Note to Practitioners—This paper is motivated by the problem that the tolerance information in the current computer-aided-design CAD systems lacks the necessary engineering semantics, which causes tolerance information that cannot be correctly used and impedes the integration of CAD and computer-aided manufacturing (CAM). Existing approaches have partially solved the problem for the pattern of holes (POH) and plane feature based on variational geometry. But the computational efficiency with the variational geometry method is very insufferable due to a lot of Boolean intersection operation. In this paper, the hole feature is mainly considered because its tolerance specification is quite different from other features and is imposed on the centerline and the surface of a hole at the same time. First, the mathematical model is given for interpreting the engineering semantics of the tolerance of the centerline and the surface based on the variational geometry, respectively. Then, the tolerance principles are further considered for compensation between the above two types of tolerance. More important, a direct method, which can largely avoid the Boolean intersection operation, is proposed for generating the variational geometry. The computational efficiency is thus improved dramatically and the variational geometry is generated almost in real time. This enables virtual assembly and virtual inspection with the tolerance information to be possible. [ABSTRACT FROM AUTHOR]

The C–K theory is a recent theory of reasoning in design. Despite many practical applications, the theory has not yet been operationalized in the form of a computational design tool. In this paper, we argue that, in order to build such tools, a third space—an environment space E—must be introduced to the theory. Therefore, we extend the C–K design theory, using ideas and principles from situated cognition. As we discuss, the new version provides a theoretical background for building personal design assistants—creative and adaptive design tools. [ABSTRACT FROM AUTHOR]

Engineering design focuses on the development of products and artefacts to satisfy the specified function. Although considerable advances have been made over the last two decades in functional modelling, there is not very much progress on commercial Computer-Aided Design (CAD) systems that really aid the designer in converting functional specifications to concept variants. Based on our previous work on Behaviour-driven Function-Environment-Structure (B-FES) modelling framework, this paper presents a functional design software system, called "FuncDesigner", to support the functional design of mechanical products through functional reasoning steps, including causal behavioural reasoning and functional decomposition. A function object library and a behaviour object library have been developed as well to serve as the knowledge base for the computerised functional modelling environment. The proposed functional design software system has been evaluated with a design example of a terminal insertion unit in an automatic assembly system for manufacturing electronic connectors. [ABSTRACT FROM AUTHOR]

The re-use of previous design knowledge is a potentially important way to improve design efficiency. To do so, both the product under study (product data) and the argumentation leading to it (process data) must be stored throughout the engineering design process. CAD systems do the former very well; the latter has to be developed. The objective of the paper is to contribute to a system able to capture design process rationale and make it available for re-use in the current design project or in further projects. The approach involves extracting elements of argumentation and maintaining connections between arguments, proposed solutions and decision-making contexts. Criteria exchanged between design participants leading to the acceptance or refusal of solutions are key clues to understanding design rationale. A descriptive model of a design process is proposed, based on features capitalising on the rationale of design: a conjecture (an element of a solution proposed for validation), a criterion (an element of evaluation of the proposal) and the interactions between them. Conjectures capture alternatives; criteria provide access to the rationale behind the alternatives. The model was validated by laboratory-based experimentation. A computer-aided tool supporting and analysing criteria–conjecture interactions was developed, focusing on the context of decision-making and currently available information. It comprises a database storing the interactions and five modules to process the data for use in a design context. The raw data in the database are abstracted into knowledge according to the manner in which a design engineer wants to retrieve and use it. This structure is represented in the form of a data-processing prototype. [ABSTRACT FROM AUTHOR]

Additive manufacturing (AM) presents designers with unique manufacturing capabilities while imposing several limitations. Designers must leverage AM capabilities – through opportunistic design for AM (O-DfAM) – and accommodate AM limitations – through restrictive (R-) DfAM – to successfully employ AM in engineering design. This dual DfAM approach – comprising O- and R-DfAM – starkly contrasts traditional, limitation-based design for manufacturing (DfM). Therefore, designers must transition from a restrictive DfM mindset towards a 'dual' design mindset. Designers' prior experience, especially with DfM could inhibit their ability to transition towards dual DfAM. On the other hand, experienced designers' auxiliary skills (e.g. with computer-aided design) could help them implement DfAM in their solutions. However, little research has studied the influence of prior experience on DfAM use in the later design stages (i.e. embodiment and detail design), and we explore this research gap. Specifically, we conducted an experimental study comprising a task-based DfAM educational intervention with first-year student designers and upper-level student designers. Participants' DfAM self-efficacy and their integration of DfAM in their solutions were compared between the two groups. From our results, we see that experienced designers report higher baseline self-efficacy with R-DfAM but not O-DfAM. We also see that experienced designers demonstrate a greater use of certain DfAM concepts (e.g. part and assembly complexity) in their designs. These findings suggest that introducing designers to O-DfAM early could help develop a dual design mindset; however, having more engineering experience might be necessary for them to implement DfAM into their designs. [ABSTRACT FROM AUTHOR]

the paper presents some new concepts applied in Computer Aided Design regarding some hardware solutions, possibilities to optimize the organization of an design office and a case study of the concurrent engineering and project management used in the design process. [ABSTRACT FROM AUTHOR]

Abstract: This short paper presents 10 challenging research areas in the general field of computer-aided design. The research problems come from the author''s personal experience, and as such are highly subjective. All findings and opinions are those of the author and do not represent any of the institutions the author is affiliated with. [Copyright &y& Elsevier]

There are various methods for performing tolerancing and robust design within a computer-aided design (CAD) framework. Recent work on fitting statistical emulators to CAD systems can be used to facilitate fast optimization geared towards robustness against input variation. After discussing available methods for tolerancing within a common framework, a comprehensive strategy for robust design is developed which involves a combination of circuit simulation, emulation and global optimization. [ABSTRACT FROM AUTHOR]

Purpose: Blended learning is an emerging trend across many educational settings, adopting the purposeful integration of traditional face-to-face and online teaching to establishing an engaging learning experience for the students. Blended learning provides an ideal platform for the implementation of reusable learning objects (RLOs) as a pedagogical tool to support classroom instruction. Design/methodology/approach: This study had conducted a quasi-experiment followed by semi-structured interviews to determine if a blended learning approach using RLOs can enhance students' learning in an undergraduate engineering computer-aided design (CAD) module. This study involved learners studying engineering in two different academic years. Findings: Students from the first year were taught using traditional face-to-face teaching approach. The cohort of students from the subsequent year adopted a blended learning approach: face to face and access to a series of RLOs. The analysis revealed statistical evidence that the use of blended learning had a significant impact on the students' end of term exam grades in the CAD module in comparison to the students who undertook traditional face-to-face teaching approach. The qualitative findings highlighted the positive impact of RLOs on students' learning behaviour, engagement and knowledge retention. Originality/value: This study provided empirical evidence of the benefits of using RLOs as a blended learning tool in engineering domain. From a theoretical perspective, the findings highlighted the importance of good instructional design and sound theoretical underpinning of the pedagogical strategy. From a practical point of view, this study informed academics on how to improve learner's academic achievement using RLOs. [ABSTRACT FROM AUTHOR]

Based upon technical feasibility and interest in Augmented Reality as a flexible framework for the development of visualization tools and human–machine interfaces for the architecture, engineering, and construction industry, a prototype for augmented reality computer aided drawing (AR CAD) is being developed as a first example and test bed for establishing the benefits of such tools. AR CAD adds an augmented reality assistant viewer to standard CAD. Following a brief description of the structure and function of AR CAD, this technical note focuses on an experiment to measure AR CAD’s utility with respect to its relative advantage over basic CAD as measured in terms of time to perform a simple conflict detection task. The basic concepts of spatial cognition are noted as key issues in exploiting the strengths of such three-dimensional visualization systems as AR CAD. Experimental results demonstrate that the spatial cognition benefits from using the AR viewer assistant for a simple spatial conflict detection task exceeds the cognition cost associated with transitioning between viewing windows when the only other method of detection is visual cues in standard CAD. [ABSTRACT FROM AUTHOR]

Design parameters and goals play important roles in design. Design goals are the required functions of the design elements and are explicitly expressed by design parameters. Design parameters also indicate the relations among design elements, by which a constraint network can be constructed and some useful information can be induced. In this study, the mechanical design process is viewed to be the assignment of design goals and their realization through the evolutionary refinement of the design parameters. The design activities are processed on traditional computer-aided design systems by specifying the shapes of the design elements. Thus, an integrated design system based on the computer-aided design system is proposed to assign the design goals and refine the values of the design parameters along the design process. The proposed design system also provides some useful facilities to a designer such as the construction of a constraint network, an evolutionary design method and a re-design plan. [ABSTRACT FROM AUTHOR]