Study On Knowledge-Based Product Design Decision Process Modeling Method

Under the background of the current digital and intelligent manufacturing,the product design is facing the double requirements of complexity and uncertainty management,the implementation of the integrated management is one of important challenges and goals in the research of complex product design.Decision-Based Design(DBD)provides a "common language"(decision)for the designers with different areas background to realize a unified description of different design problems.From the perspective of System Engineering,the design process behaviors in design reflect the complexity of product design,such as the refinement and solution of the design problem,and the planning and organization of decision-making activities.Meanwhile,due to the coexistence of various uncertainties in the design,the integrated management of uncertainty also increases the complexity of product design.To increase the designer’s ability on the understanding and prediction of design process behaviors in design,and improve the efficiency and effectiveness of the decision-making,this paper focuses on the management of the complexity and uncertainty in the product design and the modeling of design decision processes.A method framework of knowledge-based product design decision process modeling is proposed,where the design strategies of decision workflows are defined with the features of flexibility,adaptability,robustness.In this paper,detailed studies are conducted on the meta-design of decision workflows,design space exploration,robust decision workflows designing;different design problems are used to verify the effectiveness of the proposed method.Finally,a knowledge-based design decision guidance system is developed.The main research contents are as follows.(1)The Method Framework of Knowledge-Based Product Design Decision Process Modeling.Different design process strategies produce different design results,the design process strategy reflects the designer’s understanding of specific design problems.The effective design process modeling method can not only reduce the number of iterations of the system design,but also improve the design efficiency.At the same time,it is beneficial to the acquisition and reuse of product and process design information and knowledge in design.To achieve a unified standardized description of different design problems and design objects,the design process of the engineering system are defined and represented from the perspective of decision based design.Based on the demand analysis of product design decision process modeling,a framework of knowledge-based decision process modeling method is proposed.The focus of this framework is to implement the decision workflows design strategy,which is to achieve a flexibility,adaptability and robustness decision workflows.The demands of complexity and uncertainty management in design are solved in the modeling of design decision process.The capture and reuse of design knowledge as well as the organization and expression are realized using the ontology-based process templates.(2)The Method of Meta-Design Process Modeling for Decision Workflows.In this part,we focus on the definition of meta-design hierarchy information in the different levels and granularities,including 5 top-level concepts and their corresponding attributes,that is,process template,support problem entity,system entity,general design knowledge,information,and knowledge.A PEI-X ontology for the meta-design is developed,and we also present the approach for the designing of meta-design hierarchy and the design process templates which are used to capture the process information in the different granularities.Finally,the design process of shell-tube heat exchanger is used to illustrate the effectiveness of the research.(3)The Method of Decision-Centric Design Space Exploration.In this part,we focus on the adaptability in the designing of decision workflows,and a method of decision-centric design space exploration(DSE)is proposed.Here,we define the scenarios of design space adjustment,a DSE ontology is developed to ensure the determination of the right combination of design information that meets the different goals and requirements set for a process chain design space under uncertainty.We demonstrate the efficacy of this template-based ontological method for design space exploration by carrying out the design of a multi-stage hot rod rolling system in steel manufacturing process chain.(4)The Method of Robust Decision Workflows Designing In this part,we focus on the robustness in the designing of decision workflows.Thus we propose an ontology for managing uncertainties and a template-based ontological method that supports the designing of decision workflows.us we propose an ontology for managing uncertainties and a template-based ontological method that supports the designing of decision workflows.Using the proposed method,a designer can accommodate uncertainties in input parameters(noise factors,control factors),simulation models,and process chain.We demonstrate the efficacy of template-based ontological method for robust decision workflows by carrying out the robust design of Reactive Particle Metal Mixtures based on a chain of continuum and microscale level simulation models.(5)The Design of Knowledge-Based Design Decision Guidance System.Based on the above theories and methods,we propose the overall architecture of the knowledge-based design decision guidance system.Here,the system requirements and main function modules are introduced,the decision-centric business process reference model is defined.We also focus on the designing of decision workflow engine and decision process modeling tools,and a system is developed based on the Java language.