Research On Intelligent Generation Method Of Knowledge Driven Machining Process

Nowadays,with the combination of intelligent technology and mechanical manufacturing technology more and more closely,intelligent technology has been widely used in production and manufacturing,and the existing manufacturing mode and industrial form are undergoing great changes.Intelligent manufacturing not only reduces the workload of process researchers,but also shows great technical advantages in improving product quality and reducing production costs.However,at present,in the application of 3D modeling technology,the enterprise still stays in the expression of the geometric feature information of the product,which is less used in the production and manufacturing,so it cannot guarantee the data unification of design and manufacturing.In the management of process data,there is no standard data management system,which leads to the lack and disorder of process data,so it cannot support the intelligent design of process.And it needs to rely on the rich process design experience of the technologists,through a large number of human-computer interaction to drive the process design.Therefore,this paper studies the intelligent generation method of knowledge driven machining process,and constructs the intelligent generation system of machining process.This paper focuses on the modeling and management of machining process knowledge,the skeleton process generation driven by CBR-RBR integrated reasoning mechanism,and accurate process generation technology based on process constraints.The main contents of this paper are as follows:(1)Modeling and management of machining process knowledge: Aiming at the problem of disordered and unmanaged machining process data,the model of acquisition,organization and management of machining process knowledge is constructed.C-A-R(concept-attributerule)graph is proposed to express the relation of process knowledge.The rapid and accurate acquisition of machining process is realized by interactive and big data mining.According to the characteristics of concept,attribute,rule and case knowledge,the method of knowledge expression and management is adopted,and the rule knowledge is abstracted into standard case knowledge,which lays a foundation for subsequent process information acquisition.(2)Skeleton process generation based on knowledge matching: This paper discusses the generation method of skeleton process,which takes the machining process of each machining feature as the constituent unit,can express the main structure of part process,and provide accurate process parameters for the subsequent generation of accurate process.By using "attribute adjacency graph with dimension information",the same machining features are combined to avoid repetitive matching.Through CBR-RBR integrated reasoning mechanism and interactive audit mechanism,the matching retrieval of process requirements and process case knowledge is realized,and the feature machining chain of all machining features is obtained to form skeleton process.(3)Accurate process generation based on process constraints: On the basis of skeleton process,the intelligent optimization and sequencing method of working steps is explored to obtain the accurate process with minimum process resource replacement.This paper analyzes the geometry,position and technological relationship between machining features,arranges the empirical constraints of machining process,puts forward the related judgment strategy of the working steps sequence matrix and the process constraint matrix,and realizes the intelligent judgment of the rationality of the working steps sequence.Through the elitist retention strategy and the improved crossover operator,the working steps sequence optimization method based on genetic algorithm is designed,and the intelligent optimization output of working steps arrangement is realized.Based on the above knowledge acquisition,organization and management model,CBRRBR integrated reasoning mechanism and genetic algorithm based working steps sequence optimization method,a knowledge driven intelligent generation system of machining process is developed on NX platform.Taking the connecting rod of marine diesel engine as an example,this paper introduces the process flow of the intelligent generation method of machining process,and verifies the practicability and effectiveness of this method.