Research On Conceptual Design Method Of Mechanical Execution System And System Implementation Technology

Conceptual design of mechanical system is the critical stage in the design process. Thedecisions made in the period of conceptual design will have significant effect on the product’sfunction, performance, cost and development cycle. As the function delivery unit of mechanicalsystem, the execution system is the key part of the entire mechanical system. Therefore, it is veryimportant to study the conceptual design phase of mechanical execution system. In recent years, alot of research work has been done by domestic and foreign experts, but there are still a lot ofproblems to be solved, and computer-aided conceptual design of execution system is still far frombeing real applicable.To address this problem, this thesis studies the conceptual design of mechanical executionsystem, including the relevant methods and system implementation technology for the executionsystem design.Firstly, with the FBS model as its theoretical basis, combined with the cognition andunderstanding of the conceptual design process, the thesis extended the FBS model to the FTPBMmodel, which stands for Function-Technology-“Process action”-“Motion behavior”-Mechanism.Based on this model, it analyzed the design process and the mapping strategies among the modellayers of conceptual execution system design. Next, it studied specifically the motion behavior,process action and their representation methods in the FTPBM model, together with a study ofmotion coordination of the execution system, which is verified by a practical example.Subsequently, based on the FTPBM model, the thesis established the framework of aconceptual design system, and some key technical problems of the software system are addressed.These include two categories of work: on the one hand, the conceptual design knowledgerepresentation of execution system and the construction of knowledge base have been studied,including motion conversion functional knowledge, mechanism knowledge and mappingknowledge, which are described in detailed and coded. On this basis, a number of knowledge baseswere developed, such as functional decomposition knowledge base, motion conversion functionknowledge base, mapping knowledge base, mechanism knowledge base and mechanismevaluation knowledge base. On the other hand, the modules of software system are studied andimplemented. The operation flow of knowledge base maintenance module, as well as the algorithmfor automated reasoning for the selection and configuration of mechanism scheme, are designed.Based on the above work, by utilizing the existing software development tools, a prototypeconcept design system software of execution mechanism was developed, which can be used for interactive functional decomposition, for knowledge enquiry, addition, delete and modification, aswell as for reasoning out configurative mechanism scheme to meet the design requirements.Finally, an execution system of powder compressing machine was studied, assisted by thedeveloped software, to demonstrate the proposed conceptual design methods. The results show thatthe proposed methods and the developed software prototype are practicable, which can be used toimprove the efficiency of design process and shorten the product development cycle.