Mereotopological assembly joint information representation for collaborative product design

In this paper we discuss an ontology-based representation method for differentiating assembly joints in collaborative and intelligent product design. As design becomes increasingly knowledge-intensive, intelligent, and collaborative, the need becomes more critical for computational frameworks that enable product development by effectively supporting the formal representation, capture, retrieval, and reuse of product knowledge. Joints are a key aspect of assembly models that are often ambiguous when model sharing takes place. Although various joints may have similar geometries and topologies, the physical implications of the selected joining processes may vary significantly. It is possible to attach notes and annotations to geometric entities in order to distinguish joints; however, such textual information does not readily prepare the model for downstream activities, such as simulation and analysis. As an illustration, analysts must read and interpret the annotations in order to develop the appropriate boundary conditions. In this work, we present an assembly design ontology that explicitly represents assembly constraints, including joining constraints, and infers any remaining implicit ones. By relating concepts through ontology technology rather than just defining data syntax, assembly and joining concepts can be captured in their entirety or extended as necessary. By using the knowledge captured by the ontology, similar looking joints can be differentiated. For this research, we used a mereotopology, which is a region-based theory for parts, and the Semantic Web Rule Language (SWRL) to represent the difference of joints and to define assembly design terms and their relationships. We also used SWRL so that the joining rules can be reasoned to differentiate assembly joints. Finally, by using an ontology, various geometrically and topologically similar joints are successfully differentiated in a standard and machine-interpretable manner.     

Ontology-based interoperation model of collaborative product development

The reuse of existing systems is an important objective of High Level Architecture (HLA) based collaborative product development systems. However, in order to reuse an existing system, its interoperation interface has to be modified so as to comply with the objective and interaction representations defined in a corresponding Federation Object Model (FOM). Such modifications imply added time and effort, which diminishes the efficiency of system reuse in collaborative product development. This paper presents a heavy-weighted ontology-based construction method for interoperation models to support the reuse of subsystems in various collaborative contexts. In this method ontologies are used to specify the semantics of object classes and interaction classes in subsystems in a formal and computer readable fashion. In doing so, a Formal Concept Analysis (FCA) like construction method is introduced to establish the original interoperation ontology from scratch. An automatic transforming method from Simulation Object Model (SOM) into interoperation ontology is also described to make existing HLA based systems easy to adopt this approach. Then a consistency verification method is introduced to guarantee the consistency of the interoperation ontologies. A case study is used to demonstrate the feasibility of the proposed method. As a human-friendly modeling method, compared with existing interoperation modeling methods the proposed method is more flexible, efficient and reliable.     

Semantic Web based innovative design knowledge modeling for collaborative design

This paper describes a study about how to use the Semantic Web technologies for innovative design knowledge modeling in a multi-agent distributed design environment. Semantic Web based knowledge modeling for innovative design is proposed as prelude to the meaningful agent communication and knowledge reuse for collaborative work among multidisciplinary organizations. A model for innovative design is proposed at first, based on which a knowledge schema is brought forward. For sharing the design knowledge among an internet-based or distributed work team, even globally, A RDF-based knowledge model is presented to realize its representation on Semantic Web. A Semantic Web based repository for innovative design and its API for topper Semantic Web applications have been also constructed. The proposed knowledge modeling extends traditional product modeling with capabilities of innovative design, knowledge sharing and distributed problem solving, and is employed as a content language within the messages in the proposed multi-agent system architecture. The proposed approach is viewed as a promising knowledge management method that facilitates the implementation of computer supported cooperative work in innovative design of Semantic Web applications.     

A framework for collaborative top-down assembly design

This paper presents a new system framework for collaborative top-down assembly design. Different from current computer-aided design (CAD) systems, the framework allows a group of designers to collaboratively conduct product design in a top-down manner. In our framework, a multi-level and distributed assembly model is adopted to effectively support collaborative top-down assembly design. Meanwhile, fine-granularity collaborative design functionalities are provided. First, the coupled structural parameters involved in the distributed skeleton models of the product can be collaboratively determined by the correlative designers based on fuzzy and utility theory. Second, agent based design variation propagation is achieved to ensure the consistency of the multi-level and distributed assembly model during the whole design process. Third, collaborative design of assembly interfaces between the components assigned to different designers is supported. The prototype implementation shows that our framework works well for supporting practical collaborative top-down assembly design.     

Design formalism for collaborative assembly design

Joints in product design are common because of the limitations of component geometric configurations and material properties, and the requirements of inspection, accessibility, repair, and portability. Collaborative product design is emerging as a viable alternative to the traditional design process. The collaborative assembly design (AsD) methodologies are needed for distributed product development. Existing AsD methodologies have limitations in capturing the non-geometric aspects of designer's intent on joining and are not efficient for a collaborative design environment. This paper introduces an AsD formalism and associated AsD tools to capture joining relations and spatial relationship implications. This AsD formalism allows the joining relations to be modeled symbolically for computer interpretation, and the model can be used for inferring mathematical and physical implications. An AsD model generated from the AsD formalism is used to exchange AsD information transparently in a collaborative AsD environment. An assembly relation model and a generic assembly relationship diagram are to capture assembly and joining information concisely and persistently. As a demonstration, the developed AsD formalism and AsD tools are applied on a connector assembly with arc weld and rivet joints.     

Ontology-based similarity for product information retrieval

Product development of today is becoming increasingly knowledge intensive. Specifically, design teams face considerable challenges in making effective use of increasing amounts of information. In order to support product information retrieval and reuse, one approach is to use case-based reasoning (CBR) in which problems are solved “by using or adapting solutions to old problems.” In CBR, a case includes both a representation of the problem and a solution to that problem. Case-based reasoning uses similarity measures to identify cases which are more relevant to the problem to be solved. However, most non-numeric similarity measures are based on syntactic grounds, which often fail to produce good matches when confronted with the meaning associated to the words they compare. To overcome this limitation, ontologies can be used to produce similarity measures that are based on semantics. This paper presents an ontology-based approach that can determine the similarity between two classes using feature-based similarity measures that replace features with attributes. The proposed approach is evaluated against other existing similarities. Finally, the effectiveness of the proposed approach is illustrated with a case study on product–service–system design problems.     

Knowledge integration and sharing for collaborative molding product design and process development

This study presents a systematic approach to developing a knowledge integration and sharing mechanism for collaborative molding product design and process development. The proposed approach includes the steps of (i) collaborative molding product design and process development process modeling, (ii) an ontology-based knowledge model establishment, (iii) knowledge integration and sharing system framework design, (iv) ontology-based knowledge integration and sharing methods development, and (v) ontology-based knowledge integration and sharing mechanism implementation. The mechanism can support collaborative molding product design and process development by providing functions of knowledge integration and sharing. Results of this study facilitate the knowledge integration and sharing of collaborative molding product design and process development to satisfy the product knowledge demands of participants, and thus increase molding product development capability, reduce molding product development cycle time and cost, and ultimately increase molding product marketability.     

A spatiotemporal information management framework for product design and assembly process planning reconciliation

This paper introduces an innovative framework for product design and assembly process planning reconciliation. Nowadays, both product lifecycle phases are quasi concurrently performed in industry and this configuration has led to competitive gains in efficiency and flexibility by improving designers’ awareness and product quality. Despite these efforts, some limitations/barriers are still encountered regarding the lack of dynamical representation, information consistency and information flow continuity. It is due to the inherent nature of the information created and managed in both phases and the lack of interoperability between the related information systems. Product design and assembly process planning phases actually generate heterogeneous information, since the first one describes all information related to “what to be delivered” and the latter rationalises all information with regards to “how to be assembled”. In other words, the integration of assembly planning issue in product design requires reconciliation means with appropriate relationships of the architectural product definition in space with its assembly sequence in terms of time. Therefore, the main objective is to provide a spatiotemporal information management framework based on a strong semantic and logical foundation in product lifecycle management (PLM) systems, increasing therefore actors’ awareness, flexibility and efficiency with a better abstraction of the physical reality and appropriate information management procedures. A case study is presented to illustrate the relevance of the proposed framework and its hub-based implementation within PLM systems.     

A distributed and interactive system to integrated design and simulation for collaborative product development

The goal of applying collaborative product development in industry has raised the need to develop software tools supporting system integration and group collaboration. Current methods and tools mainly focus on the collaborative creation of design components and assemblies. However, few of them support the collaborative work in developing simulation models so that proposed design concepts and solutions can be evaluated by integrating expertise from several disciplines. The purpose of this research is to develop a distributed and interactive system on which designers and experts can work together to create, integrate and run simulations for engineering design. To develop such a system, a number of issues, e.g. effectiveness and efficiency of modeling work, the re-use of models, interaction and cooperation, accuracy of simulation, collaborative operation on models, etc., need to be addressed. This paper describes an open architecture to developing simulations for engineering design in a distributed and collaborative environment, identifies a set of key issues raised in this architecture, and presents the techniques employed in our solution.     

A holistic approach to collaborative ontology development based on change management

This paper describes our methodological and technological approach for collaborative ontology development in inter-organizational settings. It is based on the formalization of the collaborative ontology development process by means of an explicit editorial workflow, which coordinates proposals for changes among ontology editors in a flexible manner. This approach is supported by new models, methods and strategies for ontology change management in distributed environments: we propose a new form of ontology change representation, organized in layers so as to provide as much independence as possible from the underlying ontology languages, together with methods and strategies for their manipulation, version management, capture, storage and maintenance, some of which are based on existing proposals in the state of the art. Moreover, we propose a set of change propagation strategies that allow keeping distributed copies of the same ontology synchronized. Finally, we illustrate and evaluate our approach with a test case in the fishery domain from the United Nations Food and Agriculture Organisation (FAO). The preliminary results obtained from our evaluation suggest positive indication on the practical value and usability of the work here presented.     

An assembly oriented design framework for product structure engineering and assembly sequence planning

The paper describes a novel framework for an assembly-oriented design (AOD) approach as a new functional product lifecycle management (PLM) strategy, by considering product design and assembly sequence planning phases concurrently. Integration issues of product life cycle into the product development process have received much attention over the last two decades, especially at the detailed design stage. The main objective of the research is to define assembly sequence into preliminary design stages by introducing and applying assembly process knowledge in order to provide an assembly context knowledge to support life-oriented product development process, particularly for product structuring. The proposed framework highlights a novel algorithm based on a mathematical model integrating boundary conditions related to DFA rules, engineering decisions for assembly sequence and the product structure definition. This framework has been implemented in a new system called PEGASUS considered as an AOD module for a PLM system. A case study of applying the framework to a catalytic-converter and diesel particulate filter sub-system, belonging to an exhaust system from an industrial automotive supplier, is introduced to illustrate the efficiency of the proposed AOD methodology.     

A semantic collaborative awareness model to deal with resource sharing in grids

Grid computing environments are set up mainly to encourage the shared use of different resources based on business/scientific needs. The way these resources are shared in terms of CPU cycles, storage capacity, software licenses etc., is normally dictated by the availability of these resources outside the local administration context. The Semantic Grid is the extension of Grid computing with Semantic Web-based technologies. The Semantic Grid represents grid management data in a machine-understandable format, and reasoning can handle complicated situations in virtual organization management. This paper presents the extension of the collaborative awareness model (CAM) to manage virtual organizations in Semantic Grid environments. CAM applies some theoretical principles of awareness models to promote resource interaction and management, as well as task delivery.     

基于Ontology的Web语言OIL及其应用

Ontology在网络信息交换中起着重大的作用,OIL是一种基于Ontology技术的Web环境下的领域模型语言。使用OIL定义的领域模型扩展了RDPS,可以实现在Web体系中的计算机可理解知识系统。将Onlology应用到Web上,就产生了语义化的Web。     

基于本体的信息处理系统的设计与实现

语义Web是W3C制定的关于下一代Web技术的一个蓝图。本体作为其中的一部分,将起到非常重要的作用。用于定义和描述Web本体的Web本体语言,尤其是由W3C所设计的OWL,将在其中扮演重要的角色。该文探讨了一个基于本体的信息处理系统的设计和实现,并分析了可扩展性、查询灵活性及逻辑推理等特点。     

Integrity validation in semantic engineering design environment

A collaborative engineering design environment has been devised based on semantic Web technologies. The Semantic Engineering Design Environment (SEDE) consists of Engineering Ontology, Design Rules, Design Database, and Design Data Web Service. The Design Data Web Service provides users APIs (Application Programming Interface) so that distributed Design Participants interface each other. The domain knowledge of design objects can be logically expressed by OWL (Web Ontology Language). Design rules regarding change management are encoded in XQuery and stored as database triggers. Once design data changes, associated design rules will be validated by database systems. In this paper we introduce the overall architecture of the collaborative engineering design environment and present working scenarios with examples.     

A negotiation methodology for multidisciplinary collaborative product design

The collaborative design of a complicated mechanical product often involves conflicting multidisciplinary objectives, thus one key problem is conflict resolution and coordination among the different disciplines. Since the characteristics such as cooperative competition, professional dependence, compromise, overall utility and so on exist in multidisciplinary collaborative design (MCD), an effective way to gradually eliminate the conflicts among the multiple disciplines and reach an agreement is the negotiation by which a compromise solution that satisfies all parties is got. By comprehensively analyzing the characteristics in MCD and considering the benefit equilibrium among discipline individuals and team, a negotiation strategy is presented, which maximize the union satisfaction degree of system overall objective under the premise of ensuring the higher satisfaction degree level of each discipline’s local objective. A design action of a discipline is abstractly expressed as a concession in the negotiation strategy, and a negotiation model used for MCD is generated by establishing the relation between concession and satisfaction degree. By the relation between satisfaction degree and objective function, the mapping relationship between satisfaction degree domain and physical domain is built to get the design solution. A negotiation process is planned, and a negotiation system framework is designed to support the negotiation among multiple disciplines and assist the different disciplines rapidly reach a consistent compromise solution. A design example of automotive friction clutch is given to illustrate the proposed method.     

Product information visualization and augmentation in collaborative design

In this paper, a collaborative system for product information visualization and augmentation is presented. The developed system allows the users, who can be remotely distributed, to view a product model, which is a geometric representation of the product, from different perspectives. They can choose to view design and product history, such as previous modification processes and feature information of the product independently. The product models displayed to the users are immediately updated after any design modifications have been made to the CAD model. Product features being discussed can be highlighted to draw the users’ attention. In addition, modifications can be displayed dynamically for the users to evaluate the design effect. The product history document module in the system provides a user-friendly interface for retrieving design records. After a specific record has been chosen, the related product model is displayed, and it can be aligned with the current product model for the ease of comparison and evaluation. The feature information of the product is displayed using virtual “floating” annotations linked to the related features. A user interface to enter annotations is provided, and the annotations entered by different users can be shared in real time. A cluster-based greedy algorithm is implemented to avoid overlapping annotations in the field of view.     

Creating shared design thinking process for collaborative design

Shared understanding about both the design content and the design process has significant meaning for collaborative design, which influences the quality of final products. Existing approaches have difficulties in supporting designers to structure and share their design thinking while they are performing practical tasks. In this paper we propose Shared Design Thinking Process Model (S-DTPM) to support collaborative design, which is based on co-evolutionary design theory and existing design rationale frameworks. Two principles for S-DTPM have been considered. The elements and representation schema of S-DTPM have been discussed in detail. Based on S-DTPM, a prototype system has been developed for supporting collaborative thinking and capturing shared design rationale. An example, collaborative design is taken to validate the proposed model. S-DTPM can help designers to create shared understanding about the design as well as record shared design thinking process for future use such as design review, design change and redesign.