Homomorphic filtering demodulation for bearing signal

Hi everyone, i want to know if is possible to applicate the Homomorphic filtering demodulation for bearing damage in matlab because after searching it , i found that it is implemented for image filtering only.

Answer 1

[Paras Gupta]

Hi Eris,

I understand that you want to use Homomorphic filtering for bearing damage analysis in MATLAB.

To apply Homomorphic filtering for bearing damage analysis, you would need to consider the bearing vibration signals instead of image data. The basic idea behind Homomorphic filtering is to separate the low-frequency and high-frequency components of a signal. This can help in enhancing the low-frequency information related to the bearing damage while suppressing the high-frequency noise or interference.

Please find the below the general workflow to implement Homomorphic filtering for bearing damage analysis in MATLAB:

1. Load the bearing vibration signal data into MATLAB.
2. Preprocess the signal if necessary, such as removing any DC offset or noise using functions like detrend, medfilt1, sgolayfilt.
3. Apply a logarithmic transformation to the signal using the log function to compress the dynamic range and emphasize low-frequency components.
4. Perform a Fourier transform on the logarithmic transformed signal using the fft function to obtain the frequency spectrum.
5. Apply a high-pass filter in the frequency domain using designfilt and filter functions to suppress the low-frequency noise and retain the high-frequency components related to bearing damage.
6. Apply an inverse Fourier transform using the ifft function to obtain the filtered signal in the time domain.
7. Optionally, post-process the filtered signal by smoothing, thresholding, etc. to enhance the bearing damage features or remove any remaining noise based on the requirements.
8. Analyze the filtered signal to detect and characterize the bearing damage.

The specific implementation details may vary depending on the characteristics of your bearing vibration signal and the type of damage you are trying to detect. You can refer to the documentations of the functions below for more details.

• https://www.mathworks.com/help/matlab/ref/detrend.html
• https://www.mathworks.com/help/matlab/ref/detrend.html
• https://www.mathworks.com/help/signal/ref/sgolayfilt.html
• https://www.mathworks.com/help/matlab/ref/log.html
• https://www.mathworks.com/help/matlab/ref/fft.html
• https://www.mathworks.com/help/signal/ref/designfilt.html
• https://www.mathworks.com/help/signal/ref/filter.html
• https://www.mathworks.com/help/signal/ref/filter.html

Hope this helps.

[Eris Prifti]

Thank you i try to implement this, but ca you give an example code if you have time?