Study On Precision Mapping Technology Of NC Machine Tool Based On Meat-Action Decomposition

Reliability allocation is a very important link in the design and development stage of CNC machine tools.The reliability allocation method is to allocate some reliability indicators to each subsystem of the CNC machine tool in a scientific and reasonable way,so that the products produced can meet expectations.Reliability level.In this paper,supported by the key projects of the National Natural Science Foundation of China,combined with the meta-action related theory,a reliability allocation method based on the Bayes-GO reliability evaluation model and a probabilistic language reliability allocation method considering the correlation of meta-action failures are proposed.The research content is as follows:(1)On the basis of discussing the concepts of meta-action,meta-action unit and meta-action chain,taking the decomposition of numerical control turntable as an example,the principles and steps of FMA(Function-Motion-Action)decomposition are elaborated in detail,and it is reliable The basic knowledge of sex-related theoretical knowledge and common reliability allocation methods is introduced,which lays a theoretical foundation for the research and analysis in the following part.(2)Aiming at the problem that complex mechanical products have multiple varieties and small batch production,which leads to insufficient reliability analysis data of the meta-action unit,the complex mechanical and electrical products are analyzed from the perspective of “function-motion-action” to the whole machine function from a dynamic perspective Perform structural decomposition.Establish a GO graph model corresponding to the FMA functional decomposition tree,and use the GO method to quantitatively analyze the reliability of the product,and finally analyze the failure importance of the meta-action unit to find the key weak links that affect the reliability of the product,which is the reliability index The distribution of weights provides a basis for decision-making.This method is mainly applicable when the historical data is available for reference when transforming old products.(3)Aiming at the problem that the traditional reliability allocation method ignores the problem of fault correlation between subsystems,a reliability allocation method for CNC machine tools considering the meta-action fault correlation is proposed.This method is based on FMA structured decomposition to decompose CNC machine tools into meta-motions step by step,and meta-motions are assigned as reliability indicators.When determining reliability influencing factors,probabilistic language terminology is used to reduce the subjectivity of experts when scoring.Based on COPRAS,the reliability allocation weights are solved.Finally,the Copula function is used to establish a metaaction reliability model with fault correlation,and the reliability index is allocated in conjunction with the model.This method is mainly applicable to the development of new products without correlation.When the data is available for reference.(4)Taking the numerical control turntable system and spindle system of a domestic machining center as an example,the two reliability allocation methods proposed were applied,and the results obtained were optimized using particle swarm optimization algorithm.Finally,the results before and after optimization were compared The analysis has realized the reasonable allocation of the reliability index of the data machine tool and verified the applicability and effectiveness of the proposed method.