The Implementation Of HHT Method Based On LabVIEW And The Application Research In The Bearing Fault Diagnosis

Hilbert-Huang Transform method proposed by NE. Huang in 1998 is a nonlinear and non-stationary signal analysis method. It has been gradually applied in many fields, such as non-destructive testing, hydromechanics, meteorology, graph and image signal processing, radar, communication, vibration test and mechanical fault diagnosis and has got good effects.LabVIEW from NI Corporation, the typical software of Virtual Instrument technology advocated software substitute for hardware in the test system or the instrument design, that is, "the software is the instrument". The modularized instrument system in computer operation is widely used worldwide. The LabVIEW software has obvious superiority over traditional programming language in the project application. Graphical programming interface, for example, has high reusability, practicability, development efficiency and powerful functions of network. It can be applied in many instruments and data acquisition hardware and support multiple systems. The LabVIEW software is widely used in real-time monitoring and on-line fault diagnosis as result of its powerful functions. Development of advanced signal processing analysis module based on the LabVIEW software platform has high research value and application prospect.In this dissertation, HHT theory is expounded in detail. Especially for the key steps of HHT, EMD and Hilbert transformation. Meanwhile, comments on some key questions of the EMD. Harmonic wave and sine frequency-modulated signal are simulated, analyzed and handled using HHT method so as to explain its algorithm principle. The commonly used time-frequency analysis method rationale was also presented and analog signal is designed, simulated and compared. From analysis result, HHT time-frequency analysis method has good time-frequency concentration and is suitable for analysis of non-stationary nonlinear signal.This dissertation briefly introduces the LabVIEW software platform and programming foundation, analyzes and describes key concepts and narrates its advantages and application prospect in condition monitoring and fault diagnosis.Based on the algorithm principle of HHT method and the programming of LabVIEW software, the signal analysis module of HHT method based on the LabVIEW software platform is developed. On the basis of this module the harmony signals are used as the testing signals which test and verify the developed software. By means of the fault experiment platform of Rolling Bearing in research institute, The fault test system of rolling bearing is builded. The single point faults of inner ring and outer ring of rolling bearing are analyzed by means of the HHT signal analysis module based on the LabVIEW software and the diagnosis results are in accord with the true faults.This dissertation successfully completed the design task and the results meet the expectation. The usual time-frequency methods are simply introduced. The theories of HHT method and the key steps of algorithm implementation are described emphatically. The analog signals are designed and are simulated by several time-frequency analysis methods. The signal analysis module of HHT method based on the LabVIEW software platform is developed which is successfully applied in the fault diagnosis signal example of rolling bearing. The results of the paper enrich the contents of the signal processing and fault diagnosis.