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With the increasing demand for multi-variety and small-batch products, it's necessary to frequently dispatch and replace the progressive press dies on the stamping production lines to ensure the diversity of processed automobile covering parts. This paper formulates a die scheduling problem with twin-crane transportation (DSP-TCT) encountered in the stamping production line, which concentrates on the scheduling of transporting dies between the production line and warehouse by twin cranes with satisfying crane distance constraint, die position constraint, and precedence constraint. To solve DSP-TCT, this paper proposes a node sequence-based ant colony optimisation algorithm (NS-ACO). In this algorithm, each node represents a single die transportation task with action and time information executed by the twin cranes. The combination of adjacent nodes with a high time utilisation rate can be accumulated as heuristic priority knowledge for guiding optimisation. To demonstrate the effectiveness of the NS-ACO algorithm, numerical experiments with three different die stacking strategies are executed. [ABSTRACT FROM AUTHOR]

Checking fixture design is a complicated task requiring a strong professional background and rich practical experience. In order to enhance design efficiency and quality, this paper proposes a computer-aided checking fixture design methodology. The key issues include a new minimal volume bounding box generation approach for workbench design, a multi-objective optimisation algorithm of locator layout for location design, a multi-surface extension and transition method for checking components design and a flexible part library system to reuse standard parts and to assemble them automatically. As an implementation of the system based on the key methods, Checking Fixture Design Wizard for automobile parts, a plug-in on CAD software, is developed. Finally, a car door checking fixture design is taken as a case study to verify its feasibility and practicability. [ABSTRACT FROM PUBLISHER]

Quick quotations for customised parts are one of the effective ways for enterprises to win the market opportunities and also play important roles in production plan. Current researches have made great advancements in this field, while most of them place emphases on the technologies for a higher accuracy as for certain category of parts. In this paper, a framework for part quotations is proposed for customised parts through rough requests, in which several published algorithms are directly implanted. First, the input parts are automatically categorised according to their shapes. Next, corresponding algorithms are invoked to estimate their prices respectively, which is transparent to users. Finally, the quoting results are presented in a uniform output. Most processes including the geometric operations can be directly handled on the website, which provides the users a convenient platform. To further improve the evaluated accuracy, relevance feedback is adopted to optimise the embedded calculating mechanisms with the gradual accumulation of cases and manual corrections. For better flexibility and extendibility, the built-in algorithms are deployed in the plug-and-play manner with the uniform data input-output interface. Later experiments validate this conception and the online system performs well especially for rod parts, box parts and mould sets, which will bring a novel way to the manufacturing enterprises in their order processing. [ABSTRACT FROM AUTHOR]

The difficulty of the 3D registration mainly lies in the huge computation for a precise alignment, especially for large data of urban scenes. In this paper, we proposed an algorithm that converts this 3D problem into 2D case. The main idea is to map the point cloud onto the image. Then, SIFT algorithm is adopted to detect the key points of the images, and key points from two images corresponding to the two point clouds ready to be registered are matched to form several pairs. Next, the key point pairs construct an intrinsic link between the images. From the one-to-one correspondence between pixel and point, this relation can be converted back to 3D space, according to which a transform matrix can be consequently established. The resultant matrix aims at guiding the spatial transform to achieve an ideal 3D registration. Later experiments illustrate that it will obtain a preferable result in much less time. [ABSTRACT FROM PUBLISHER]

Three-dimensional (3D) models are the most important carriers of CAD/CAE/CAPP/CAM, and usually they contain more information than practically needed as for some given applications, which may occupy superfluous storage space in computers. As a result, the handling speed also inevitably becomes slow, and certain inner secrets may be disclosed in the collaborative environment. The lightweight of large 3D models is an effectual solution. In this paper, a lightweight algorithm with intelligent information reduction for large-scale assembly is proposed to generate simple model by using their intrinsic structures. This algorithm aims at reducing the sizes of 3D CAD models within five steps and three levels from coarse to fine: components (including sub-assemblies and parts), feature and exterior geometry. Key strategies, such as components suppression, feature simplification and hollows seaming, are used in the processing. Finally, a shell model is created to represent the original one in subsequent applications. Different from 3D meshed model simplification, the proposed method is capable of reserving all necessary assembly interfaces for the further usage. Later experiments show that the lightweight method can obtain satisfactory results in practical design with preferable performance. The lightweight technology can be widely applied in many fields such as large-scale virtual assembly and movement simulation. [ABSTRACT FROM AUTHOR]

Collaborative product development is a strategic approach for manufacturing enterprises to succeed in the competitive market. Issues of information and knowledge sharing within the value chain are regarded as the most significant aspect of collaborative product development and the sharing is based on geographically distributed business domains. To support this issue, this paper discusses internet-based intelligent system architecture for collaborative product development built upon service-oriented architecture that is a profitable infrastructure for handling distributed heterogeneous resource sharing. The system utilises basic and extensible services to provide efficient and effective knowledge-sharing functionality on-demand. A Java-enabled solution together with artificial intelligence techniques is employed to develop such a networked system. Finally, a case study is presented to illustrate how the tool and die makers are involved and cooperate with the product designers to make an optimal design collaboratively. [ABSTRACT FROM AUTHOR]

Modern-day products are usually designed cooperatively by teams of experts, each with their own areas of expertise. In order to make the collaboration go smoothly, task planning is necessary, including task decomposition and task assignment. Because of differing viewpoints, evaluation standards and the domain knowledge of the collaborative teams, conflict is unavoidable and should be resolved as soon as possible. In this paper, an integration-based conflict resolution system (ICRS) is put forward to manage and resolve conflict in a life cycle way. A hierarchical constraint network was used to detect conflict, and three methods in ICRS were used for conflict resolution: the knowledge-based method was used for knowledge conflicts and schema conflicts, while constraint relaxation was used for data conflicts. For those conflicts that are hard to resolve using the above two methods, a negotiation method is used. An example is presented to illustrate the process of conflict resolution. [ABSTRACT FROM AUTHOR]