Study On KBE System Of Overall Design For Buses

With the development of the society and economy, the requirements of market to the manufacturering industry are being more and more higher. On the premise of providing good quality products, the manufactures also try their best to launch the product with the shortest process, the lowest cost and the highest seriation, especially for the wide varieties and few batches bus manufacturing. So, the manufactures have to minimize the development time, reduce the cost and seriate the product. The overall design of the bus is the key point in the development of the bus. It will affect the success or failure of the product development directly. Therefore, it will be great significant to manufactures to use the modern product design support technology to shorten the development time, improve the quality and decrease the cost. Now, the time is the knowledge economy time, and the knowledge has become a kind of estate. Fortunately, the modern product design support technology of knowledge-based enginering(KBE) not only can help the enterprise to realize the above-mentioned purposes, but also is the key technology for the enterprise to enhance its autonomous development ability and kernel competence. So, What is introduced in this paper is to apply the KBE system to the overall design of the bus. Following is the summary of the researching:① Analyzing the background, definition, meaning, system structure, sort and the key technology of KBE; Researching the knowledge obtaining, expressing, reasoning, management, product modeling and integration technology of the isomeric system of KBE; Expounding the development trend of the KBE technology and its researching situation in buses at home and abroad; Introducing the function of KBE technology application in the product development; Putting forward the problems resulting from applying KBE technology to the overall design of the bus, which have to resolved.② According to the industry characteristics, analyzing the main contents of the bus design, including the outline dimension fixing, the chassis selecting, the engine locating, the body design, the cab layout, human engineering and so on; introducing the defects of CAD and CAE in the bus overall design practice; raising the idea of the bus design system based on the knowledge engineering, including system structure, knowledge system modeling, functional module and system integration and so on. ③ The expression of the knowledge in the knowledge database is different from the general CAX system, and it leads to the mismatch between KBE and CAX. Because the EXPRESS language of STEP standard has features of the standardization, integration and neutralization, and it can be supported by most CAX systems, the EXPRESS language of STEP standard is put forward as the modeling language of the knowledge in knowledge system in order to solve the bottleneck problem between the knowledge system and general CAX system, and this is firstly applied in the bus overall design. ④ The development of Network provides the most effective information carrier to knowledge share and reuse. The component and part database, which are based on Network and contented with the international standard CAD part database standard (i.e.ISO 13584) and the STEP standard, are brought forward in this paper. It can make the data of the different CAX systems be shareable and reusable in different enterprises all over the world or in different departments of a enterprise. As an example, the component and part database of the bus overall design is studied. Additionally, the custom-made requirment can be reached through the customer-design participation by use of Network and KBE technology.⑤ The reuse of knowledge is the key technology of KBE system, which is involved in the theoretical method of reuse reasoning, reuse control strategy, and reuse process information model. Therefore, on the basis of the reuse method, the reasoning reuse technology of EXPRESS language based on the STEP is raised, and then taking the reuse of the bus body in the overall design as...