Hi everybody,
Thank you for sharing valuable information in this forum
Here is my problem. I am continuously collecting vibration data from a set of
bearings on a spindle. I am interested in tracking certain bearing related
frequencies such as outer race ball pass frequency (BFPO), etc, in order to
determine the state of the bearings (healthy operation, worn out, ...)
My sampling rate is set to 10 kHz, and I collect 30 seconds of data and dump it
into a file. Later, I open the files and perform fft on them in Matlab. As the
test progresses, it is relatively easy to see the increase in amplitude of the
BFPO visually by utilizing the plotting tools. My question is, is there a way to
extract the frequency information programmatically in order to be able to plot
its progression over time. Sometimes, the tests might take anywhere up to 3-4
days, and that is a lot of data to plot and examine visually.
Thank you in advance for your help.
Tracking certain frequencies over time
Started by ●January 1, 2009
Reply by ●January 2, 20092009-01-02
Well, you are already doing this as far as I understand your problem.
Just, make a sliding window, take FFT and with the help of sampling
frequency, capture the complex FFT value corresponding to your
frequency of interest. Dump these values and later plot it... Once you
have this data, you can manipulate it the way you want.
By programmatically you mean avoiding FFT?
Ubaid Abdullah
http://dspdotcomm.blogspot.com
--- In m..., a.soylemezoglu@... wrote:
>
> Hi everybody,
> Thank you for sharing valuable information in this forum
>
> Here is my problem. I am continuously collecting vibration data from
a set of
> bearings on a spindle. I am interested in tracking certain bearing
related frequencies such as outer race ball pass frequency (BFPO),
etc, in order to determine the state of the bearings (healthy
operation, worn out, ...)
>
> My sampling rate is set to 10 kHz, and I collect 30 seconds of data
and dump it into a file. Later, I open the files and perform fft on
them in Matlab. As the test progresses, it is relatively easy to see
the increase in amplitude of the BFPO visually by utilizing the
plotting tools. My question is, is there a way to extract the
frequency information programmatically in order to be able to plot its
progression over time. Sometimes, the tests might take anywhere up to
3-4 days, and that is a lot of data to plot and examine visually.
>
> Thank you in advance for your help.
>
Just, make a sliding window, take FFT and with the help of sampling
frequency, capture the complex FFT value corresponding to your
frequency of interest. Dump these values and later plot it... Once you
have this data, you can manipulate it the way you want.
By programmatically you mean avoiding FFT?
Ubaid Abdullah
http://dspdotcomm.blogspot.com
--- In m..., a.soylemezoglu@... wrote:
>
> Hi everybody,
> Thank you for sharing valuable information in this forum
>
> Here is my problem. I am continuously collecting vibration data from
a set of
> bearings on a spindle. I am interested in tracking certain bearing
related frequencies such as outer race ball pass frequency (BFPO),
etc, in order to determine the state of the bearings (healthy
operation, worn out, ...)
>
> My sampling rate is set to 10 kHz, and I collect 30 seconds of data
and dump it into a file. Later, I open the files and perform fft on
them in Matlab. As the test progresses, it is relatively easy to see
the increase in amplitude of the BFPO visually by utilizing the
plotting tools. My question is, is there a way to extract the
frequency information programmatically in order to be able to plot its
progression over time. Sometimes, the tests might take anywhere up to
3-4 days, and that is a lot of data to plot and examine visually.
>
> Thank you in advance for your help.
>
Reply by ●January 9, 20092009-01-09
One thing you can dois to utilizethe Wavelet transform (when youneed to know
which frequency components occur when, there you need a Wavelet transfrom) to
look at the time-frequency spectrum at a time. Wavelet transformcould be
considered asa kind of short-time FFT to see the change of spectrum over time.
Take a look into Wavelet tutorials.
Good Luck,
TayyaR.
--- On Thu, 1/1/09, ubaid_abdullah wrote:
From: ubaid_abdullah
Subject: [matlab] Re: Tracking certain frequencies over time
To: m...
Date: Thursday, January 1, 2009, 9:42 PM
Well, you are already doing this as far as I understand your problem.
Just, make a sliding window, take FFT and with the help of sampling
frequency, capture the complex FFT value corresponding to your
frequency of interest. Dump these values and later plot it... Once you
have this data, you can manipulate it the way you want.
By programmatically you mean avoiding FFT?
Ubaid Abdullah
http://dspdotcomm. blogspot. com
--- In matlab@yahoogroups. com, a.soylemezoglu@ ... wrote:
>
> Hi everybody,
> Thank you for sharing valuable information in this forum
>
> Here is my problem. I am continuously collecting vibration data from
a set of
> bearings on a spindle. I am interested in tracking certain bearing
related frequencies such as outer race ball pass frequency (BFPO),
etc, in order to determine the state of the bearings (healthy
operation, worn out, ...)
>
> My sampling rate is set to 10 kHz, and I collect 30 seconds of data
and dump it into a file. Later, I open the files and perform fft on
them in Matlab. As the test progresses, it is relatively easy to see
the increase in amplitude of the BFPO visually by utilizing the
plotting tools. My question is, is there a way to extract the
frequency information programmatically in order to be able to plot its
progression over time. Sometimes, the tests might take anywhere up to
3-4 days, and that is a lot of data to plot and examine visually.
>
> Thank you in advance for your help.
>
Good Luck,
TayyaR.
--- On Thu, 1/1/09, ubaid_abdullah wrote:
From: ubaid_abdullah
Subject: [matlab] Re: Tracking certain frequencies over time
To: m...
Date: Thursday, January 1, 2009, 9:42 PM
Well, you are already doing this as far as I understand your problem.
Just, make a sliding window, take FFT and with the help of sampling
frequency, capture the complex FFT value corresponding to your
frequency of interest. Dump these values and later plot it... Once you
have this data, you can manipulate it the way you want.
By programmatically you mean avoiding FFT?
Ubaid Abdullah
http://dspdotcomm. blogspot. com
--- In matlab@yahoogroups. com, a.soylemezoglu@ ... wrote:
>
> Hi everybody,
> Thank you for sharing valuable information in this forum
>
> Here is my problem. I am continuously collecting vibration data from
a set of
> bearings on a spindle. I am interested in tracking certain bearing
related frequencies such as outer race ball pass frequency (BFPO),
etc, in order to determine the state of the bearings (healthy
operation, worn out, ...)
>
> My sampling rate is set to 10 kHz, and I collect 30 seconds of data
and dump it into a file. Later, I open the files and perform fft on
them in Matlab. As the test progresses, it is relatively easy to see
the increase in amplitude of the BFPO visually by utilizing the
plotting tools. My question is, is there a way to extract the
frequency information programmatically in order to be able to plot its
progression over time. Sometimes, the tests might take anywhere up to
3-4 days, and that is a lot of data to plot and examine visually.
>
> Thank you in advance for your help.
>
