The Research For Remote Condition Monitoring And Fault Diagnosis Technology Based On Virtual Instrument

With the development of Internet, condition monitoring and fault diagnosis of devices is advancing from traditional single device and field mode to distributed and remote mode, which can reduce the time of collecting fault, improve the efficiency of diagnosis system, and favor accumulating data and sharing resources. It will bring enormous economic performance, suffer the domestic and international extensive valuing increasingly. Today, the technologies of remote machinery fault diagnosis are the trend of the machinery fault diagnosis development. The task of this subject is to design a remote condition monitoring and fault diagnosis system based on the Technology of Virtual Instrument. The main theories and key technologies in this paper include the time-frequency theory, real-time data transport by DataSocket, technique of database, EMAIL, FTP ,etc.At first, the time-frequency theory is studied, a simulated signal is used to compare the difference between different time-frequency analysis methods. STFT, Wigner-Ville, Choi-Williams, Cone-Shape Kernel are used to analyze the signals of normal and fault state of outside-rolling, rolling bearing, inside-rolling, then uses image classification method to classify the signals. It is certified that the method can get a good result. The accuracy rate is 100% when use the way of processing the signals by STFT then using similarity measures to classify the signals.Then, the whole scheme is recommended, including the construction of hardware, the development platform of software, the function analysis of the modules. And the key technologies of system implementation are discussed. Remote on-line monitoring is realized by the DataSocket, sampling number and sampling frequency are banded with testing data by property node, in order to assure data consistency. File system and database system combining method is realized by using FTP to transfer the data files and in the same time using database to record the information of measurement. The abnormal data will be sent to the analysis client by email. Rolling bearings database is constructed in order to calculate the characteristics frequency of bearings, users can operate the database, containing adding, selecting and deleting records.At last, the fault diagnosis system can run normally after the debugging. The system can fit the need of remote monitoring and fault diagnosis, it can be widly used in company, feed the real-time status information of the equipment to the office client, so measures can be took to hold back the accident. On the other side, it can be used in the research laboratory and school teaching.