Research On Safety EvaluationTechnology Of NC Machine Tool Transportation Process Based On Condition Monitoring

As the "industrial master machine",CNC machine tool is the basis of the development of manufacturing industry,and also the expensive basic manufacturing equipment.Because of the increasing demand for CNC machine tools,the research on them is becoming more and more intensive.However,due to the frequent occurrence of logistics accidents in the transportation process of CNC machine tools,huge economic losses are caused to enterprises.However,there are few reports on the safety of the transportation process of CNC machine tools in China.At present,there is no corresponding transportation standard in the field of numerical control machine tool transportation,and no perfect transportation management and evaluation mechanism has been established.Usually,after the CNC machine reaches the user's enterprise,it only carries out a simple accuracy test,but it is difficult to define and trace the fault or damage of the machine due to transportation.Therefore,in this paper,the status monitoring of the transportation process of CNC machine tools and the safety evaluation of the transportation process based on the monitoring data are taken as the main research contents,and the safety evaluation method of the transportation process of CNC machine tools based on the status monitoring is proposed,the main contents are as follows:1.In order to collect the environmental data of the transportation process of CNC machine tools and monitor the transportation of machine tools,the software and hardware of the transportation condition monitoring device of CNC machine tools are designed and developed.According to the technical requirements of the state monitoring in the transportation process of CNC machine tools,the acceleration,inclination and temperature and humidity of three-way impact are taken as the important technical indicators of the state monitoring in the transportation process of CNC machine tools.The overall scheme of the monitoring device is designed with the modular design concept,and the design of each functional module of the monitoring device is completed.At the same time,the monitoring system software of the transport process status of the CNC machine tool is developed.Finally,the real-time monitoring of the characteristic parameters in the transport process of the CNC machine tool is realized,which provides the basic data for the subsequent research on the transport process safety evaluation technology of the CNC machine tool.2.In order to ensure the safety of machine tool transportation process,a pre transportation safety evaluation of CNC machine tool based on grey clustering theory is proposed.First of all,the actual situation of CNC machine tool before transportation is analyzed,including personnel quality,vehicle status,machine tool packaging,transportation route and transportation environment.Based on the definition of grey category(safe state,safer state,more dangerous state,dangerous state),this paper classifies the evaluation indexes,brings the indexes into the corresponding whitening weight function to get the membership degree of the grey category,and then determines the weight of each evaluation index by AHP,and finally determines which grey category the whole transportation process belongs to,Realize the safety state evaluation of CNC machine tools before transportation.3.According to the characteristics of the monitoring indexes of the transportation process of CNC machine tools,a method of processing the monitoring data of the transportation process of CNC machine tools based on wavelet packet decomposition is proposed.Firstly,wavelet packet decomposition is used to extract and filter the time-domain and frequency-domain information of the state index signal in the transportation process of CNC machine tools,and the data types that need to be analyzed are determined.Among them,eight time-frequency features and a series of time-domain features are obtained by three-layer wavelet packet decomposition and time-domain feature extraction of road condition data(acceleration and inclination).Through feature selection,11 typical features are selected as the basis for subsequent data analysis.Through the analysis and processing of simulation test data,the evaluation standard of NC machine tool transportation process data is obtained.4.Based on SVM and weighted D-S evidence theory,a safety evaluation method of NC machine tool transportation process is proposed.Through SVM to train and test the characteristics of the simulation test data in the above 3,a classification model is obtained,which is used to classify the road condition data in the actual transportation process,and to statistically classify the other data except the road condition according to the evaluation criteria in the above 3,and to obtain the membership vector of all kinds of data in the actual transportation process for the transportation safety state As the input of transportation safety evaluation model,the safety state evaluation matrix is formed.The data of the matrix is fused by the weighted D-S evidence theory,and finally the safety evaluation of the whole transportation process of CNC machine tools is completed.This paper studies the early troubleshooting test of CNC machine tools,and proposes to combine the safety evaluation results of machine tool transportation with the early troubleshooting test,in order to stimulate the failure or damage of machine tools caused by the transportation process,and make the machine tools pass through the early failure period smoothly.The evaluation method of safety state in the transportation process of CNC machine tools put forward in this paper effectively solves the problems such as the imperfection of the transportation management mechanism of CNC machine tools,the definition and tracing of the faults caused by the transportation,etc.,and relies on the transportation monitoring equipment of CNC machine tools developed in this paper,which provides guarantee for the accumulation of the transportation data of CNC machine tools and the subsequent quantitative analysis and research in this field,with a wide range General application value.