System Design Of Intelligent NC Machine Tool Fault Diagnosis System

NC machine tool is a kind of basic equipment that used for industrial production. It is a key element which determines air, water and electricity industries development. NC machine tool’s failure will affect the normal operation of the machine tools, even lead to production pause. So developing independent, user-oriented, integration of intelligent NC machine tool fault diagnosis system, can promote the development of numerical control technology and improve the machining accuracy. It also can improve the reliability of the machine tool operation. It can improve the efficiency of NC equipment and even the whole manufacturing process.This paper analyses the causes of the failure according to the structural characteristics of NC machine tools. Vibration, temperature and noise are chosen as the test object. The vibration, temperature and acoustic emission sensor are installed in the numerical control machine tool’s key mechanical parts. PCI high speed data acquisition card is used by the hardware of NC machine tool fault diagnosis system.After data preprocessing, the features were extracted by the time domain, frequency domain and time-frequency domain analysis. It can realize the purpose of real-time detection of machine tool by the BP neural network fault diagnosis.The intelligent fault diagnosis system of NC machine tool has three subsystems including the data acquisition system, performance degradation assessment system and fault early warning system. VC++, MATLAB and Oracle were used to complete the software design of framework system. Visual studio2010was used as the software development platform. VC++was used to collect data and write service program. MFC interface is used to display each subsystem. MATLAB was used to calculate the acquisition data.Practical results show that the intelligent fault diagnosis system is effective to predict failure condition of the NC machine tools and improve the reliability of the machine tool.