Research On High-speed Train Welding Expert System Based On Knowledge Engineering

At present, lightweight design and aluminum alloy body have been widely adopted inHigh-speed train. It’s normal that welding acts as an important technology in the manufacturingprocess of aluminum alloy body all the time, and the welding process ensures the global quality ofhigh-speed train. In this paper, an expert system of high-speed train with welding processes is estab-lished, which based on the knowledge engineering. And there are three major functional modules inthe system, including welding procedure qualification, weldability analysis and welding process de-sign.First of all, the knowledge base is established based on principals of knowledge engineering. Thepaper finishes the knowledge acquisition of implicit knowledge and explicit knowledge of aluminumalloy, with classifying the data and information of welding manual, welding standard, welding condi-tion and mature welding process documents. Then the appropriate knowledge representation modesare selected to represent the knowledge; after that, the establishment of the knowledge base hierarchymodel was completed, with determining system inference mechanism according to the characteristicsof welding knowledge.Secondly, in order to meet the demand for welding production of high-speed train, the paper de-signs the innovative function of process evaluation necessity judgment in batch and welding proce-dure qualification projects extraction, which based on ISO15614-2standard and combined with thecharacteristics of high-speed train’s welding procedure qualification. As known the welding proce-dure qualification system is composed of series of functions, such as weld importing, weld merging,process evaluation necessity judgment, welding procedure qualification projects extraction and weldexporting. After above, it realizes the welding procedure qualification autoimmunization.Moreover, the paper completes the establishment of weldability comprehensive analysis andevaluation model by means of using a combination of case-based reasoning and rule-based reasoningmechanism. And through the implementation of the model, including determine evaluation indicators,indicators dimensionless, weighted allocation, weighted sum, eventually the intuitive analysis andevaluation results are obtained, which provides an effective basis for the subsequent welding processdesign.At last, the welding process design system is established in this paper by analysis of weldingprocess characteristics of aluminum alloy body. What’s more, the contents of the procedures contain the designs of welding joints, the designs of groove, the selections of welding consumables, the selec-tions of pre-welding treatment, the selections of postweld heat treatment, and the choices of weldingparameters for different welding process, etc. In summary, the realization of system functions playeda certain role in designing of the welding process.