Yutaka Nomaguchi

Physical concept ontology for the knowledge intensive engineering framework

Knowledge intensive engineering aims at flexible applications of a variety of product life cycle knowledge, such as design, manufacturing, operations, maintenance, and recycling. Many engineering domain theories are organized and embedded within CAD and CAE tools and engineering activities can be formalized as modeling operations to them. Since most of domain theories deal with the physical world and can be associated with physical concepts, a physical concept ontology can form a common ontology to integrate engineering models that are formed based on domain theories. This paper reports a physical ontology-based support system for knowledge intensive engineering called Knowledge Intensive Engineering Framework (KIEF) to integrate multiple engineering models and to allow more flexible use of them. First, the paper describes the physical ontology as the core of KIEF and an ontology-based reasoning system, called a pluggable metamodel mechanism, to integrate and maintain relationships among these models. The pluggable metamodel mechanism uses a metamodel that represents the designers mental model about a design object as a concept network model. The designer builds and decomposes a functional hierarchy from functional specifications with an FBS (Function-Behavior-State) modeler. He/She then maps the functional hierarchy into a metamodel using physical features that are building blocks for conceptual design. Then, the pluggable metamodel mechanism enriches the information contained in the metamodel by using causal dependency knowledge about the physical world and by building and analyzing various engineering models. We demonstrate the power of KIEF by illustrating a design case performed on KIEF.

DESIGN RATIONALE ACQUISITION IN CONCEPTUAL DESIGN BY HIERARCHICAL INTEGRATION OF ACTION, MODEL AND ARGUMENTATION

This paper proposes a framework for acquiring design rationale in the conceptual design. Knowledge management is getting much attention for supporting the early phases of design process. While the research outcomes on design rationale might be useful in the direction, their capabilities are still far from practice. Such outcomes are categorized into model-based, argumentation-based and action-based frameworks. These are complementary when knowledge acquisition facility and explanatory power is considered. This paper introduces the hierarchical model of design rationale for overcoming the shortcomings of individual approaches under three frameworks. It consists of argument level, model operation level and action level. Argument level represents a designer’s decision making process. Model operation level represents a sequence of design operations. A design operation follows and is followed by a design stage, which records a design snapshot over conceptual product model. Action level represents design process as a sequence of operation primitives, which are elementary and atomic operations on the product model. These linkages of three levels enable to automatically acquire design rationale through operation primitives over a design support system.Copyright

Knowledge representation framework for interactive capture and management of reflection process in product concepts development

A design process can be characterized by reflection-in-action; that is, the process consists of a series of problem solving activities and each is embodied with a problem and a solution. In this process, a designer represents a hypothetical concept on each design alternative, deploys and verifies the concept from multiple viewpoints considering other alternatives, and modifies it. An advanced integrated design environment should be based on a representation framework that embodies this process of reflection in concept development, which usually remains in the realm of the designers tacit knowledge. This paper proposes a knowledge representation framework for an integrated design environment, named DRIFT (Design Representation Integration Framework of Three layers), which interactively captures and manages reflection processes of generating and verifying design concepts. The core of DRIFT is a three-layered design process model of actions, operations, and argumentation. This model integrates various design tools and captures performed design activities. The action level captures the sequence of design operations. The model operation level captures the transition of design states, recording a design snapshot over design tools, which are integrated through ontology-based representation of design concepts. The argumentation level captures the process of defining problems and corresponding alternative solutions. Integration of three levels with a template of design operation extracted from Design-For-X approaches enables a proposed system to interactively and efficiently capture and manage the process of design concept development through operations over design tools. A design operation template works to limit the number of links between the three levels remaining easy to manage its semantics. This paper also demonstrates a prototype implementation of DRIFT and its application to conceptual design of a small mechatronic system with a system modeling method. The paper concludes with a discussion of some future issues.

Knowledge Model for Managing Product Variety and Its Reflective Design Process

Recent manufacturers have been utilizing product families to diversify and enhance the product performance by simultaneously designing multiple products under commonalization and standardization. Design information of product architecture and family is inevitably more complicated and numerous than that of a single product. Thus, more sophisticated computer-based support system is required for product architecture and family design. This paper proposes a knowledge model for a computer-based system to support reflective process of designing product architecture and product family. This research focuses on three problems which should be overcome when product family are modeled in the computer system; design repository without data redundancy and incorrectness, knowledge acquisition without forcing the additional effort on the designer, and integration of prescriptive models to support early stages of the design process. An ontology that is a foundation of a knowledge model is defined to resolve these problems. An example of designing an air conditioner product family is shown to demonstrate the capability of the system.Copyright

10. Document-based Design Process Knowledge Management for Knowledge Intensive Engineering

In this paper, we propose a fundamental idea of a new CAD architecture to facilitate design knowledge management. This architecture is useful to develop an advanced design support system that encourages a designer to externalize his/her knowledge during a design process and facilitates sharing and reuse of such externalized design knowledge in later stages. We also describe an implementation of this idea called DDMS (Design Documentation Management System). DDMS works as a front-end to KIEF (Knowledge Intensive Engineering Framework) we have been developing. We also illustrate an example of machining tool design to demonstrate the features of DDMS.

Planning method of creative and collaborative design process with prediction model of technical performance and product integrity

This article proposes a new method of design process planning based on a growth curve model with a fuzzy number managing uncertain design progress. Because a product consists of many interdependent subsystems, an engineering design process consists of two different knowledge creation activities, that is, an activity to enhance the technical performance level of each subsystem, which is called task, and an activity to enhance the integrity level among the subsystems. This research models the progress of the technical performance and the integrity with the growth curve. A numerical design structure matrix is used to represent task dependency and collaboration efficiency. A design process plan is evaluated by the probability that the technical performance will achieve the target level of design target. A proposed method facilitates a project manager to explore various process plans, to assess their risks, and to decide better plans. A planning example of a student formula car design project demonstrates that a project manager can quantitatively compare alternative process plans and choose the better plan. That result shows the possibility of the proposed model toward an optimization of process planning.

Design Knowledge Management Based on a Model of Synthesis

In this paper, we report the development of a design knowledge management system, called DDMS (Design Documentation Management System). By recording design documents during design, DDMS encourages a designer to externalize his/her knowledge and facilitates sharing and reuse of such externalized design knowledge in later stages. DDMS works as a front end to KIEF (Knowledge Intensive Engineering Framework), which we have been developing over years. KIEF is capable of integrating multiple design object models and of maintaining consistency among these models. DDMS automatically generates design documents after analyzing design log data and guides designers with design process knowledge based on a model of synthesis. We also illustrate an example of laser lithography design to demonstrate the features of DDMS.

Fundamental framework toward optimal design of product platform for industrial three-axis linear-type robots

Abstract This paper discusses an optimization-based approach for the design of a product platform for industrial three-axis linear-type robots, which are widely used for handling objects in manufacturing lines. Since the operational specifications of these robots, such as operation speed, working distance and orientation, weight and shape of loads, etc., will vary for different applications, robotic system vendors must provide various types of robots efficiently and effectively to meet a range of market needs. A promising step toward this goal is the concept of a product platform, in which several key elements are commonly used across a series of products, which can then be customized for individual requirements. However the design of a product platform is more complicated than that of each product, due to the need to optimize the design across many products. This paper proposes an optimization-based fundamental framework toward the design of a product platform for industrial three-axis linear-type robots; this framework allows the solution of a complicated design problem and builds an optimal design method of fundamental features of robot frames that are commonly used for a wide range of robots. In this formulation, some key performance metrics of the robot are estimated by a reduced-order model which is configured with beam theory. A multi-objective optimization problem is formulated to represent the trade-offs among key design parameters using a weighted-sum form for a single product. This formulation is integrated into a mini–max type optimization problem across a series of robots as an optimal design formulation for the product platform. Some case studies of optimal platform design for industrial three-axis linear-type robots are presented to demonstrate the applications of a genetic algorithm to such mathematical models.

Design Achievement Model for Planning Creative and Concurrent Design Process

Planning of an upstream design process that includes creative and concurrent activities has become more important for product development in a competitive market. A significant characteristic of upstream planning is that the design process is one of knowledge creation. During this process, a designer makes progress toward a more advanced knowledge level that corresponds to a more advanced design achievement. In most cases of a creative and concurrent design process, however, a designer has to compromise design achievement because of constraints such as delivery time, cost, and another designer’s intention. Therefore, in planning a design process, it is more essential to set an acceptable level of design achievement and to predict whether or not a planned design process can ensure this level, than to predict the design time needed to totally achieve the design goals. This paper proposes a new method of design process planning that focuses on quantitative prediction of knowledge level achieved in a creative and concurrent design process. A growth curve model using fuzzy numbers is introduced to predict the final achievement of each task and final achievement of consistency between tasks after running a planned design process. The reliability model of a serial system is used to calculate the total acceptability of the design achievement. An experimental system that supports design process planning based on the proposed method is developed. This paper demonstrates its application to a student design project in order to show the power of the method.Copyright

Design Project Planning Method With Task Option Model and Two-Level Multi-Objective Optimization

This paper proposes a new optimization-based project planning method that aims at a Pareto-optimal of the potential product performance of designed product and a project failure risk. A task option model is introduced for risk assessment of option-based project management. As its planning includes a number of various design variables and various evaluation indices, in order to solve such a complicated problem with a reasonable computation cost, this research separates the optimization problem into two phases, i.e., (i) defining of process architecture and organization structure and (ii) scheduling of resource allocation into activities. This paper demonstrates its application to a student formula design project. A proposed optimization method facilitates a project manager to explore various process plans with assessing their risks.Copyright