The Development And Application For Condition Monitoring And Fault Diagnosis System Of Numerical Control Manchines

NC machine tools is an advanced processing equipment which is highly automated andcomplex structure, it has characteristics of high precision, high efficiency, high automatedhigh flexibility, intensive technologies and involve multiple disciplines, it needs highrequirement technologies for related persons, therefore, timely fault diagnosis andmaintenance is very difficult and also makes the maintenance method and means complex, themaintenance cost is also very big, therefore, to develop powerful and perfect system of NCmachine tools monitoring and fault diagnosis system and formulating scientific andreasonable maintenance strategy is very necessary.This topic develops a complete set of NC system including state monitoring, signalanalysis, fault diagnosis, the results show, data base establishment and management based onfully understanding the characteristics of NC machine working principle, structure and currentfault diagnosis technologies. The system applies virtual instrument development environment,uses parts of the software function instead of expensive hardware detection diagnosisinstruments, save the cost of developments; The user information management design, meetsthe needs of many users and much time interval; the combination of using sensor technology,virtual development technique and computer technology develops real-time online monitoringsystem，not only monitor the parameters of the NC machine tools, real-time knows theequipment condition, but also can timely issued fault alarms, the application of digital signalprocessing (DSP) technology, greatly improving the system analysis of the data andinformation handling ability; Combined the technology of feature extraction and patternrecognition technology rapidly find faults with collecting data and fault diagnosis，thesystem is more accurate and more timely troubleshooting, and forecasts trend according toequipment state, also can guide operators to regulate and control arrangements, extendequipment life cycle, as far as possible to reduce the frequency of equipment failure.Empiricalmode decomposition method is put forword to unify the concept of instantaneous frequency,atthe same time,the concept of basic model component,a new time and frequency analysismethod is produced which is based on the time and frequency basic signal,it stands out the local characteristics of the data and produced more accurate and more effective featureinformation of original signal it not only help the maintenance persons quickly find the causeof the problem, consult knowledge base information,make the maintenance plan,and can alsorecord history fault,so as to fast find subsequent faults,timely maintenance faults shortenmaintenance time,reduce downtime, improve the accuracy and the speed ofmaintenance,reduce the maintenance cost.