Research On Some Key Theory Problems Of Product Systematic Design

Developed from the mode based on experience to the mode based on science theory, product design theory and method has been a relative perfect system which can guide product designs. Although the product design theory and method has been widely used in practice, but many problems of theory and practice need to be studied and solved. With many years experience, Prof. Wen Bangchun, member of Chinese Academy of Science, presented the product integrated design theory and method based on system engineering (SE) which can program a design on objectives, ideas, environments, processes, contents, methods and quality checking. Including functional optimum design, dynamic optimum design, intelligent optimum design and visual optimum design, the product integrated design method named "1+3+X" was set up. As the continuous work of the product integrated design theory and method based on SE, some key theory problems of product systematic design were studied. Systematic research method was mainly used: Firstly, researches in the paper were based on ideas of SE. Secondly, structured process models of different design stage were established. Both theoretical research and case study were used. Conclusions of research are as follows:(1) On the basis of researching on design theories and methods at home and abroad, especially on the product integrated design theory and method based on SE, the process model of product systematic design was set up.(2) Some basic concepts like function, performance, quality and relationships between them were studied. The concepts above were defined, and the product quality model, based on function and performance, was established. The basic concept system with function, performance and quality as the core was set up. The basic concept system provided the foundation of researches in paper.(3) A method to acquire design requirements (DRs) by investigating customer requirements (CRs ), design environments and design risks was proposed. Acquiring process model of DRs for product lifecycle was set up. A modeling method of quality-oriented DRs(DRMQ) was proposed, and the model of DRs was set up. A method to determine quality-oriented technical parameters and a quality-oriented QFD model were proposed. Furthermore, an investigation process model of product design was established.(4) A new F-S mapping model named FMS was set up. A mapping model based on FMS, FMSC to support functional optimum design was set up. Furthermore, the process model of functional optimum design based on FMSC was set up. The F-S mapping process based on FMS and the creation of an innovative concept of engine were studied though the example. The correctness and guidance of FMS and FMSC for functional optimum design were proved by an example of functional optimum design of straight-conchoid engine.(5) Main framework and process model of dynamic optimum design were set up. Incidence equation of design objectives, design parameters and design methods was established. As a main method of profound dynamic optimum design, the method of multi-body system dynamics was studied. Effects of multi-body dynamics simulation for performance-oriented dynamic optimum design were shown by the simulation of a side planet cage in the tracked armoured vehicle, which partly interpret the connotation of profound dynamic optimum design.