17 research outputs found

    Coordination approaches and systems - part I : a strategic perspective

    Get PDF
    This is the first part of a two-part paper presenting a fundamental review and summary of research of design coordination and cooperation technologies. The theme of this review is aimed at the research conducted within the decision management aspect of design coordination. The focus is therefore on the strategies involved in making decisions and how these strategies are used to satisfy design requirements. The paper reviews research within collaborative and coordinated design, project and workflow management, and, task and organization models. The research reviewed has attempted to identify fundamental coordination mechanisms from different domains, however it is concluded that domain independent mechanisms need to be augmented with domain specific mechanisms to facilitate coordination. Part II is a review of design coordination from an operational perspective

    A platform cascading method for scale based product family design.

    Get PDF
    In this dissertation, a product family design method for scale based products leveraged from multiple platforms is presented. A product family is a set of related products derived from a product platform. Product family design involves designing the platform and also leveraging the different product variants from the platform. A common approach to the product family design is to treat it as a design optimization problem, so that tradeoff analysis can be performed between commonality and individual product performance.In the evaluation stage, evaluation functions are used to evaluate the family of products leveraged from the platform. After Evaluation of the products leveraged, PCM uses a cascading formulation to generate subsequent platforms from the initial platform. Cascading generates new platform by converting the platform parameters from the previous platform to a scale parameter to leverage the set of products that have poor performance. The method is illustrated using two examples: (1) axial pump product family design and (2) universal electric motor product family design. The method can be easily implemented in gradient based optimization tools and can be used design scale based product families in a time efficient manner.A product family based on a single platform may lead to poor performance of the product family. A better approach is to leverage the products from multiple platforms. This approach offers more challenges to the designer. The designer must now determine: the optimum number of product platforms that are required, the values of platform parameters for each platform, the products that are leveraged from each platform and the value of scale parameters.In this dissertation, a Platform Cascading Method (PCM) is presented which is capable of designing the family of products based on multiple platforms. PCM is comprised of three stages: (1) Single platform stage; (2) Evaluation stage; and (3) Cascading stage. In PCM, the family is first leveraged using a single platform. The non platform scale based design problem has the structure of a Mixed Integer Non Linear Problem (MINLP) due to the combinatorial nature of the platform commonality parameters and continuous product parameters. Solving MINLPs are not straightforward and require high amount of expertise and time in solving the problem and hence transform to high product lead time. In PCM, the non platform specified product family design formulation is converted from a MINLP to a NLP by relaxing the platform commonality parameters to continuous parameters and then mathematically constraining to produce discrete results in the end

    A multi-agent approach for design consistency checking

    Get PDF
    The last decade has seen an explosion of interest to advanced product development methods, such as Computer Integrated Manufacture, Extended Enterprise and Concurrent Engineering. As a result of the globalization and future distribution of design and manufacturing facilities, the cooperation amongst partners is becoming more challenging due to the fact that the design process tends to be sequential and requires communication networks for planning design activities and/or a great deal of travel to/from designers' workplaces. In a virtual environment, teams of designers work together and use the Internet/Intranet for communication. The design is a multi-disciplinary task that involves several stages. These stages include input data analysis, conceptual design, basic structural design, detail design, production design, manufacturing processes analysis, and documentation. As a result, the virtual team, normally, is very changeable in term of designers' participation. Moreover, the environment itself changes over time. This leads to a potential increase in the number of design. A methodology of Intelligent Distributed Mismatch Control (IDMC) is proposed to alleviate some of the related difficulties. This thesis looks at the Intelligent Distributed Mismatch Control, in the context of the European Aerospace Industry, and suggests a methodology for a conceptual framework based on a multi-agent architecture. This multi-agent architecture is a kernel of an Intelligent Distributed Mismatch Control System (IDMCS) that aims at ensuring that the overall design is consistent and acceptable to all participating partners. A Methodology of Intelligent Distributed Mismatch Control is introduced and successfully implemented to detect design mismatches in complex design environments. A description of the research models and methods for intelligent mismatch control, a taxonomy of design mismatches, and an investigation into potential applications, such as aerospace design, are presented. The Multi-agent framework for mismatch control is developed and described. Based on the methodology used for the IDMC application, a formal framework for a multi-agent system is developed. The Methods and Principles are trialed out using an Aerospace Distributed Design application, namely the design of an A340 wing box. The ontology of knowledge for agent-based Intelligent Distributed Mismatch Control System is introduced, as well as the distributed collaborative environment for consortium based projects

    Ant colony optimization based simulation of 3d automatic hose/pipe routing

    Get PDF
    This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.This thesis focuses on applying one of the rapidly growing non-deterministic optimization algorithms, the ant colony algorithm, for simulating automatic hose/pipe routing with several conflicting objectives. Within the thesis, methods have been developed and applied to single objective hose routing, multi-objective hose routing and multi-hose routing. The use of simulation and optimization in engineering design has been widely applied in all fields of engineering as the computational capabilities of computers has increased and improved. As a result of this, the application of non-deterministic optimization techniques such as genetic algorithms, simulated annealing algorithms, ant colony algorithms, etc. has increased dramatically resulting in vast improvements in the design process. Initially, two versions of ant colony algorithms have been developed based on, respectively, a random network and a grid network for a single objective (minimizing the length of the hoses) and avoiding obstacles in the CAD model. While applying ant colony algorithms for the simulation of hose routing, two modifications have been proposed for reducing the size of the search space and avoiding the stagnation problem. Hose routing problems often consist of several conflicting or trade-off objectives. In classical approaches, in many cases, multiple objectives are aggregated into one single objective function and optimization is then treated as a single-objective optimization problem. In this thesis two versions of ant colony algorithms are presented for multihose routing with two conflicting objectives: minimizing the total length of the hoses and maximizing the total shared length (bundle length). In this case the two objectives are aggregated into a single objective. The current state-of-the-art approach for handling multi-objective design problems is to employ the concept of Pareto optimality. Within this thesis a new Pareto-based general purpose ant colony algorithm (PSACO) is proposed and applied to a multi-objective hose routing problem that consists of the following objectives: total length of the hoses between the start and the end locations, number of bends, and angles of bends. The proposed method is capable of handling any number of objectives and uses a single pheromone matrix for all the objectives. The domination concept is used for updating the pheromone matrix. Among the currently available multi-objective ant colony optimization (MOACO) algorithms, P-ACO generates very good solutions in the central part of the Pareto front and hence the proposed algorithm is compared with P-ACO. A new term is added to the random proportional rule of both of the algorithms (PSACO and P-ACO) to attract ants towards edges that make angles close to the pre-specified angles of bends. A refinement algorithm is also suggested for searching an acceptable solution after the completion of searching the entire search space. For all of the simulations, the STL format (tessellated format) for the obstacles is used in the algorithm instead of the original shapes of the obstacles. This STL format is passed to the C++ library RAPID for collision detection. As a result of using this format, the algorithms can handle freeform obstacles and the algorithms are not restricted to a particular software package

    A CAD tool for design space exploration of embedded CPU cores for FPGAs.

    Get PDF

    Interoperability-based optimisation of architectural design

    Get PDF
    As a major contributor to the planetary greenhouse effect, construction industry needs to adopt sustainability at the core of its activities - to reverse or slow down the impacts of climate change. Increased collaboration among stakeholders along with analysis/performance based decision making is the way forward for enhanced sustainability. Emphasis is placed on the process of shared creation through multi-disciplinary collaboration, enabled by the implementation of IT (Information Technology) that acts as a platform to augment our ability to communicate. Developments in the Construction IT have been product oriented and aimed at solving particular domain problems usually with a narrow focus - further reducing the accessibility and interoperability of information over the lifecycle stages. Advances in the semantics based interoperable data standards, such as IFC (Industry Foundation Classes) offer significant advantage in removing such barriers to successful vertical and horizontal integration of software tools and process. The use of building simulation in architectural design requires specialist knowledge and a rich set of information about the proposed building which are not available to the design team at early stages. Standards based mapping of information for input processing of the simulation engines can act as an alternative to simplified tools supporting the exploratory nature of design. Detailed based input processing also restricts the use of simulation to occasional validation of solutions - even during detailed design stages. For a directed exploration of the solution space, numerical optimisation methods can be applied to enhance simulation assisted design. Successful application of optimisation methods pivots on the ability of the analysis and decision making components of the software to communicate with each other without the loss of data semantics. To realise this potential, a process-oriented integrated framework based on the interoperability of information and software tools have been developed and implemented in this thesis. For horizontal integration of domain specific tools through intra-software messaging, ardML - an XML (eXtensible Markup Language) based schema has been developed which attempts to connect non-interoperable software tools. Multi-disciplinary environmental design of buildings has been chosen as the domain of discourse. The framework currently employs industry standard zonal building simulation as an analysis tool and gradient-based mathematical optimisation methods for informed decision making. Interoperability among tools, processes and information has been achieved through the implementation of IFC based data model. The modular nature of the object-oriented framework allows incorporation of existing and future tools. The applicability of the framework has been investigated in the early stages of architectural design, in particular the selection of form and orientation - considering the environmental aspects. The implementation of the framework at an ambiguous and exploratory stage of design reinforces its applicability in a wider industry context

    Knowledge-based inventive conceptual design

    Get PDF
    Conceptual design is the first phase of the design process. Most basic functions of a new product and the solutions for solving design problems are generated in this critical phase, which will affect the attributes in the later detailed design process. Conceptual design, especially the process of concept generation, is an innovation process that is achieved by human intelligence. The intuition and experience of designers play a significant role during the design process which is hard to be replaced by computer-aided tools or artificial intelligence technology. TR1Z is an inventive problem-solving tool to help people improve creativity. It is applied in this work to generate creative design concepts. The TRIZ inventive principles are extended by integrating other TRIZ tools and TRIZ-derived tools. These principles are also restructured by the inspiration of I-Ching. The Behaviour-Entity representation of inventive principles enables the generation of new and innovative solutions based on TRIZ. The TRIZ Contradiction Matrix (CM) and inventive principles are then used to develop the TRIZ-based concept generation approach by adding constraints to the standard Behaviour-Entity representation of TRIZ. This approach is developed to retrieve modified TRIZ inventive principles and to generate new solutions by re-organising the BEC (Behaviour-Entity-Constraint) representation of principles according to the conflicting design requirements. Finally, a negotiation-based approach is integrated with an existing no-compromise approach to develop a knowledge-based system for automatically detecting and resolving conflicts. The recommendation is given as an output arranged by weight to help the designer improve creativity and efficiency for concept generation and conflict resolution in conceptual design. The approach is implemented by using a rule-based language, JESS. A case study of aircraft fuselage layout design is presented to demonstrate the benefits of using this conflict resolution system.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

    Knowledge-based inventive conceptual design

    Get PDF
    Conceptual design is the first phase of the design process. Most basic functions of a new product and the solutions for solving design problems are generated in this critical phase, which will affect the attributes in the later detailed design process. Conceptual design, especially the process of concept generation, is an innovation process that is achieved by human intelligence. The intuition and experience of designers play a significant role during the design process which is hard to be replaced by computer-aided tools or artificial intelligence technology. TR1Z is an inventive problem-solving tool to help people improve creativity. It is applied in this work to generate creative design concepts. The TRIZ inventive principles are extended by integrating other TRIZ tools and TRIZ-derived tools. These principles are also restructured by the inspiration of I-Ching. The Behaviour-Entity representation of inventive principles enables the generation of new and innovative solutions based on TRIZ. The TRIZ Contradiction Matrix (CM) and inventive principles are then used to develop the TRIZ-based concept generation approach by adding constraints to the standard Behaviour-Entity representation of TRIZ. This approach is developed to retrieve modified TRIZ inventive principles and to generate new solutions by re-organising the BEC (Behaviour-Entity-Constraint) representation of principles according to the conflicting design requirements. Finally, a negotiation-based approach is integrated with an existing no-compromise approach to develop a knowledge-based system for automatically detecting and resolving conflicts. The recommendation is given as an output arranged by weight to help the designer improve creativity and efficiency for concept generation and conflict resolution in conceptual design. The approach is implemented by using a rule-based language, JESS. A case study of aircraft fuselage layout design is presented to demonstrate the benefits of using this conflict resolution system

    Ant colony optimization based simulation of 3d automatic hose/pipe routing

    Get PDF
    This thesis focuses on applying one of the rapidly growing non-deterministic optimization algorithms, the ant colony algorithm, for simulating automatic hose/pipe routing with several conflicting objectives. Within the thesis, methods have been developed and applied to single objective hose routing, multi-objective hose routing and multi-hose routing. The use of simulation and optimization in engineering design has been widely applied in all fields of engineering as the computational capabilities of computers has increased and improved. As a result of this, the application of non-deterministic optimization techniques such as genetic algorithms, simulated annealing algorithms, ant colony algorithms, etc. has increased dramatically resulting in vast improvements in the design process. Initially, two versions of ant colony algorithms have been developed based on, respectively, a random network and a grid network for a single objective (minimizing the length of the hoses) and avoiding obstacles in the CAD model. While applying ant colony algorithms for the simulation of hose routing, two modifications have been proposed for reducing the size of the search space and avoiding the stagnation problem. Hose routing problems often consist of several conflicting or trade-off objectives. In classical approaches, in many cases, multiple objectives are aggregated into one single objective function and optimization is then treated as a single-objective optimization problem. In this thesis two versions of ant colony algorithms are presented for multihose routing with two conflicting objectives: minimizing the total length of the hoses and maximizing the total shared length (bundle length). In this case the two objectives are aggregated into a single objective. The current state-of-the-art approach for handling multi-objective design problems is to employ the concept of Pareto optimality. Within this thesis a new Pareto-based general purpose ant colony algorithm (PSACO) is proposed and applied to a multi-objective hose routing problem that consists of the following objectives: total length of the hoses between the start and the end locations, number of bends, and angles of bends. The proposed method is capable of handling any number of objectives and uses a single pheromone matrix for all the objectives. The domination concept is used for updating the pheromone matrix. Among the currently available multi-objective ant colony optimization (MOACO) algorithms, P-ACO generates very good solutions in the central part of the Pareto front and hence the proposed algorithm is compared with P-ACO. A new term is added to the random proportional rule of both of the algorithms (PSACO and P-ACO) to attract ants towards edges that make angles close to the pre-specified angles of bends. A refinement algorithm is also suggested for searching an acceptable solution after the completion of searching the entire search space. For all of the simulations, the STL format (tessellated format) for the obstacles is used in the algorithm instead of the original shapes of the obstacles. This STL format is passed to the C++ library RAPID for collision detection. As a result of using this format, the algorithms can handle freeform obstacles and the algorithms are not restricted to a particular software package.EThOS - Electronic Theses Online ServiceGBUnited Kingdo
    corecore