Ontology-based method for automatically generating reference-free geometric error extraction schemes

Abstract

The invention belongs to the field of geometric error measurement and computer application and relates to an ontology-based method for automatically generating reference-free geometric error extraction schemes. The method comprises the following steps: 1, carrying out standardized design on a part according to a new-generation GPS standard; 2, extracting measurement information of the parts; 3, constructing a reference-free geometric tolerance specification matrix M<GTS, k * 3> of the part; 4, constructing a constraint relation matrix M<CON, (k * n)> between fitting export elements and actual components; 5, constructing an assertion formula set A<GTS> representing reference-free geometric tolerance specification information of the part; 6, constructing an assertion formula set A<CON> representing constraint relationships between the fitting derived elements and the actual components; 7, using Protege software to construct an ontology of a non-reference geometric error extraction scheme; 8, defining generation rules of a non-reference geometric error extraction scheme by adopting a semantic network rule language; 9, reasoning to obtain an optional extraction scheme; 10, determining a final extraction scheme.

Description

technical field [0001] The invention belongs to the field of geometric error measurement and computer application, and relates to an automatic generation method of an ontology-based geometric error extraction scheme without reference, which can be used for the extraction of discrete points on the surface contour of parts without reference requirements for geometric errors, and is used for the extraction of discrete points on the surface of parts. Extraction provides a standardized, reasonable and fast automatic generation method. Background technique [0002] Geometric error (according to whether there is a benchmark requirement, it is divided into geometric error with benchmark and geometric error without benchmark) has a direct impact on the assembly accuracy, working accuracy, service life and other performance of machines and instruments. In order to control the geometric error of machine parts, Improving the accuracy of the machine and prolonging the service life, ensur...

AI Technical Summary

Problems solved by technology

However, the semantic information of tolerances is still difficult to exchange between heterogeneous CAD systems, and cannot be understood and shared by computers

[0006] The second category is the Standard for the Exchange of Product model data (STEP) used in today's engineering. The EXPRESS tolerance information representation language used in this method can establish a grammatically consistent tolerance information representation model, but it cannot express it explicitly The semantics of tolerance information cannot meet the needs of semantic representation and exchange of tolerance information

However, this method is only used in the tolerance design stage, and has not been applied in tolerance detection and evaluation

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