Research On A Knowledge Base For Geometrical Product Specification

Geometrical Product Specification and verification (GPS) standard system is the most fundamental standard system, and the foundation of quality management and automatization integrated system for the manufacturing industry. GPS knowledge base is constructed with database and knowledge engineering technique for New GPS standard system and further integration of CAX system. The knowledge base will help designers, manufacturing engineers and metrologists get onto the road of the new GPS, promote revolutionary changes in China's system of standards and metrology, and accelerate the implementation of the new GPS. It also will constitute a uniform verification rule, which specified operations of design, manufacture and metrology, to confirm whether quality of geometrical product meet its functional requirement. In the paper, the basic theory, the key technology of New GPS is investigated. The framework of GPS knowledge base is constructed based with databases based on the general matrix model and Inference Mechanisms based on the duality principle of New GPS. Then, as an example of a typical feature diameter, a data structure of diameter tolerance with the characteristics of design, manufacturing and verification is designed for GPS knowledge base, analyzing on the data flow of diameter tolerance design and verification in general GPS matrix. An arithmetic model for the least squares circle (LSC) based on the norm theory, one of verification arithmetic of diameter tolerance, is designed. Moreover, an ARX program used the 3rd developing tool named ARX2002 is developed to test GPS knowledge base. The ARX program triumphantly extended some appropriate measuring information specified by New GPS for diameter tolerance design in AutoCAD2002 software.