Research On Vibration Signal Based On Envelope Spectrum Analysis And Its FPGA Implementation

Vibration is a common phenomenon of the mechanical equipment operation. Through the extraction of the vibration signal, mechanical equipment running status can be analyzed. Due to the rolling bearing is the key to equipment parts and closely related to equipment status, the study of vibration signal of rolling bearing has important significance. Envelope spectrum analysis method is a commonly used analysis way of vibration signal. For improving the running speed of the algorithm and fast results, it can be done by FPGA. To complete the above requirements, a vibration test system analysis system has been designed. This paper revolves around this topic has carried out the following work:(1) A hardware modules of vibration signal acquisition is designed. According to the characteristics of the vibration signal from vibration acceleration sensor as the data picking device, through the modulation circuit design of the collected signal preprocessing. After the A/D conversion circuit, control chip will handle the storage and process the signals that through Wi-Fi transmission to the terminal device.(2) The vibration signal characteristics are extracted. Firstly, it analyses the processing methods of vibration signals commonly used and introduces the amplitude domain analysis,Fourier analysis, wavelet analysis and the theory of Hilbert envelope spectrum analysis.Compared the several theoretical methods, an analysis is put forward based on the wavelet decomposition and the Hilbert envelope spectrum of vibration signal analysis method. Using the theory of wavelet decomposition in signals in different frequency bands, it extracts failure information of frequency. Then it realizes this method on FPGA and finds out the fault characteristic frequency by the Hilbert envelope spectrum analysis.(3) The fault characteristic frequencies are derived. It gets the results using the vibration data acquisition hardware device to collect the bearing with damage on ring and combing with wavelet and Hilbert envelope spectrum to analyze on the rolling bearing experiment platform.After that, compares the results of FPGA with MATLAB.Comparing the theoretical value and experimental value get by FPGA and MATLAB shows that this vibration signal collection and analysis system feasible can extract the characteristic information of vibration signal quickly and efficiently.