The Research Of Fault Diagnosis Based On Virtual Instrument

In this paper, virtual instrument is combined to circuit fault diagnosis. The paper constructs a prototype platform for fault diagnosis based on virtual instrument. It focuses on modeling method using features of ATLAS signal model and the application of EMD method in circuit fault diagnosis.At first, the paper summarizes the development and the actuality of the study on virtual instrument and circuit fault diagnosis theory, and discusses the merits and structure of the virtual instrument technology. Then the framework of the whole platform is introduced. Because of the large-scale characteristic, modular design using COM technology is put forward as the way to implement the platform. Furthermore, the application framework and the packaging of the virtual instrument configuration module are specially studied. The platform so that has good features of commonality and expansibility.Later this paper describes the ATLAS 2K standard definition and hierarchical structure of the signal. As a universal testing language, ATLAS 2K gives a hierarchical signal classification method. Signal classification can simplifies well through the succession act of this method. The paper analyzes the way to realize signals using this method, proposes the configuration programs and parameters of the basic signals, and presents the signal modules which is appropriate to call instruments of sorts based on signal. Thus, the platform can call the instruments signal-oriented, and the operations are simplified.Finally, this paper researches on the keystone and arithmetic of EMD, applied it into the fault diagnosis system. The time-frequency analytic procedure using EMD, is considered as an important breakthrough recently while the analytic way based on Fourier Transform is used to linear and stationary spectrums. EMD analytic procedure has the characteristic of adaptability, can analyze non-linear and non-stationary signal powerfully, and especially gets a favorable effect in the analysis of complex signals. Through the research of the arithmetic flow and data instance, the paper lays out the implementation of EMD in the circuit fault diagnosis, and encapsulates it as a module into the platform. The arithmetic achieves good results in the singular points detection of circuit diagnose and significantly improves the accuracy of fault detection.