Research On Method Of Product Variant Design Based On Generalized Modularization And Its Application

In this dissertation, the theory, methods and technologies of variant design are studied systematically. A new method to construct variant design platform for mechanical products based on generalized modular is proposed. Technically, applying the design technologies of generalized modular and Case-Based Reasoning (CBR), the platform system integrates the functional structural models by constructing product generalized modular to achieve the parallelization and integration of product variant design. Consequently, the platform shortens variant design cycle and insures its quality. Through constructing the platform system of variant design platform system based on generalized modular, the main achievements of this dissertation are as followings.(1) The conceptual model of generalized modular is extended, and the framework of variant design based on generalized modular is established. To meet the features and requirement of product variant design, the structure model of generalized modular are subdivided into geometric model, analysis model, scheme design model, draws and etc. With integration and application of design technologies for generalized modular and CBR, the system framework of variant design is constructed based on generalized modular to finish the selection of design concept, the simulation analysis and performance evaluation of the design.(2) The representation method of directed graph of parameter connection structure for generalized modular is proposed, and a parameter connection structure is established. According to the structure and relation complexity of parameter connection for product variant design, and the directed graph of parameter connection structure for generalized modular is established with the directed graph theory. The properties of directed graph for parameter connection structure are researched to establish a math theory of parameter connection structure for generalized modular. Using the algorithm and mathematical description of the directed graph, the horizontal edges of the graphs are decomposed for establishing a tree-structured parameter connection structure. The new parameter connection structure ensures the rationality of parameter connection and the validity of parameter drive.(3) The mutil-model information integration is realized with the central data-base technology. To ensure data consistency of product variant design process, the mutil-model information integration is realized with the central data-base technology by establishing case information of generalized modular, scheme design model, CAD model and CAE model. Those models are integrated with scientific data-base structure to realize parallelization and integration from program design to detailed design. And the variant design knowledge is embedded into these models for effective reuse of knowledge.(4) A strategy model of multi-level case adaptation for variant design process is established. According to the hierarchy relation of variant design process, product case representation, case-base structure and case retrieval method are constructed respectively to ensure the applicability of process of product variant design, and the process of case adaptation is divided into three phases, which include scheme design modification, variant design modification of generalized modular, part features and drawing modification. The process of multi-level case adaptation can ensure the stability and effective control of variant design process with human-computer interaction.(5) A variant design platform system based on generalized modular for concrete mixing station is developed. The successful implementation in enterprise testifies the feasibility and validity of several technologies and methods presented in this dissertation.