The Research Of Bearing Malfunction Diagnosis Based On Embedded System

Roller bearings are one of most used and important mechanical parts in rotating machines, and vnlnerable to damage. Many faults of rotating mechanism are related to the state of roller bearings. The performance of roller bearings directly affects the performance of the whole machine. Thus, developing state testing and fault diagnosis of roller bearings is necessary.Based on the understangding of bearing vibration test technology and bearing fault analysis theory, this thesis puts forword the the rolling bearing fault diagnosis method of the resonance demodulation and wavelet analysis. In these methods, characteristic information for faults is gained from rolling bearing vibration signals. By using these methods, valid results are obtained.This thesis analyzes the fault principle and the fault vibration types. The means of the fault diagnosis of the rolling bearing are also introduced in detail. This thesis introduces the method of the fault diagnosis of the rolling bearing baesd on some character parameters. In this method, the part of pretreatment and character parameters in domain are introduced briefly. We give a simple bearing test by this method.Then, this thesis presents the method of resonance demodulation, which includes the design of filter, envelop demodulation and spectrum zooming. This thesis gives the simulation of the method based on matlab and the realization on DSP. Throuth processing and analysis of many data, the diagnosis result is satisfactory.Lastly, we know that different types of bearings have different character frequencies, so in the method of resonance demodulation, it is needed to design different band-pass filters. In order to predigest the program, an envelope analysis approach based on wavelet multiresolution analysis and reconstruction is proposed. This method adopts different wavelet genes, so it can carry out different band-pass filters which have different center frequency and bandwidth. This method is very applicable in nonstationary vibration signals, such as the bearing signals. This thesis introduces the basic theory of wavelet, and gives the simulation of this method based on matlab and presents the realization of the method on DSP. This method is applied into the embedded bearing fault diagnosis system, and gets better diagnosis result than the method of resonance demodulation.