Vibration
I have been using Stamps and Scenix chips for the better part of
two years, and I have a number of apps up and running.
However, I have just been talking to a friend who wants to
measure vibration in machinery, and I have been unable to
find any mention of such an app in any of the lists of apps
for the Stamp or elsewhere.
Could anyone out there point me in the right direction for
perhaps choosing what chips might be able to measure
strain and.or vibration?
Any help gratefully received.
JP Harrison
two years, and I have a number of apps up and running.
However, I have just been talking to a friend who wants to
measure vibration in machinery, and I have been unable to
find any mention of such an app in any of the lists of apps
for the Stamp or elsewhere.
Could anyone out there point me in the right direction for
perhaps choosing what chips might be able to measure
strain and.or vibration?
Any help gratefully received.
JP Harrison
Comments
sensor, interfacing it to an A/D converter, and capturing the
wave generated from a bearing.
What I'd like to do is to sense when the bearing has some
sort of fault, typically a spalled ball bearing or a faulty race.
I am assuming that I would have to use the SX to get high
enough sampling, but maybe someone who has some experience
could help me out here.
Thanx in advance......JP Harrison
may be a starting point.
ACJacques
Harrison, JP wrote:
>
> I am looking at the possibility of using some sort of vibration
> sensor, interfacing it to an A/D converter, and capturing the
> wave generated from a bearing.
>
> What I'd like to do is to sense when the bearing has some
> sort of fault, typically a spalled ball bearing or a faulty race.
>
> I am assuming that I would have to use the SX to get high
> enough sampling, but maybe someone who has some experience
> could help me out here.
>
> Thanx in advance......JP Harrison
>
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
or the bearing? It would produce a voltage relative to the level of
vibration.
> An audio mike tunned for frequency and/or noise level of a bad bearing
> may be a starting point.
> ACJacques
>
> Harrison, JP wrote:
> >
> > I am looking at the possibility of using some sort of vibration
> > sensor, interfacing it to an A/D converter, and capturing the
> > wave generated from a bearing.
> >
> > What I'd like to do is to sense when the bearing has some
> > sort of fault, typically a spalled ball bearing or a faulty race.
> >
> > I am assuming that I would have to use the SX to get high
> > enough sampling, but maybe someone who has some experience
> > could help me out here.
> >
> > Thanx in advance......JP Harrison
> >
> >
> >
> > Your use of Yahoo! Groups is subject to
http://docs.yahoo.com/info/terms/
>
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
Say I sample the wave (actually the ADC) that vibrates at
200-400 Hz. If the shaft is slightly out of round - it always is
to a certain extent - then the "vibration" is what the shaft
rotation is.
But if the bearing is failing (broken ball, say), then there
will be smaller amplitude vibrations of a higher frequency
"riding" on the larger, lower frequency wave. At least, that's
how I envision it.
What I then need to do is to sample the wave at some frequency
that must be at least double that of the expected higher frequency,
which might be 2000Hz or even more.
Has anyone done that - and what sampling rate do I need in order
to use a Fast Fourier Transform to detect these small vibrations?
Again, any hints or help gratefully received....JP
How about a piezo transducer attached to whichever is stationary, the race
or the bearing? It would produce a voltage relative to the level of
vibration.
> Harrison, JP wrote:
> >
> > I am looking at the possibility of using some sort of vibration
> > sensor, interfacing it to an A/D converter, and capturing the
> > wave generated from a bearing.
> >
> > What I'd like to do is to sense when the bearing has some
> > sort of fault, typically a spalled ball bearing or a faulty race.
> >
> > I am assuming that I would have to use the SX to get high
> > enough sampling, but maybe someone who has some experience
> > could help me out here.
> >
> > Thanx in advance......JP Harrison
> >
> >
> >
> > Your use of Yahoo! Groups is subject to
http://docs.yahoo.com/info/terms/
>
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
Use a 'notch' filter to de-tune your RPM frequency. The remaining
signal should be the rotational abnormalities.
>Yes, that's the starting point. Now comes the difficult part....
>
>Say I sample the wave (actually the ADC) that vibrates at
>200-400 Hz. If the shaft is slightly out of round - it always is
>to a certain extent - then the "vibration" is what the shaft
>rotation is.
>
>But if the bearing is failing (broken ball, say), then there
>will be smaller amplitude vibrations of a higher frequency
>"riding" on the larger, lower frequency wave. At least, that's
>how I envision it.
>
>What I then need to do is to sample the wave at some frequency
>that must be at least double that of the expected higher frequency,
>which might be 2000Hz or even more.
>
>Has anyone done that - and what sampling rate do I need in order
>to use a Fast Fourier Transform to detect these small vibrations?
>
>Again, any hints or help gratefully received....JP
>
>
>How about a piezo transducer attached to whichever is stationary, the race
>or the bearing? It would produce a voltage relative to the level of
>vibration.
> > Harrison, JP wrote:
> > >
> > > I am looking at the possibility of using some sort of vibration
> > > sensor, interfacing it to an A/D converter, and capturing the
> > > wave generated from a bearing.
> > >
> > > What I'd like to do is to sense when the bearing has some
> > > sort of fault, typically a spalled ball bearing or a faulty race.
> > >
> > > I am assuming that I would have to use the SX to get high
> > > enough sampling, but maybe someone who has some experience
> > > could help me out here.
> > >
> > > Thanx in advance......JP Harrison
Beau Schwabe IC Mask Designer
National Semiconductor Network Products Division
500 Pinnacle Court, Suite 525 Mail Stop GA1 Norcross, GA 30071
it's instrumentation amplifier.)
You'll need to collect data and perform an FFT or
wavelett transform on it. You'll want to sample
synchronously with the rotation of the shaft - i.e. 128
samples/rev, or 256 samples/rev, etc. More is better -
but more compute intensive. Keep the number of samples
as powers of two - it makes the FFT easier.
Ususally this sort of data is displayed as a "waterfall
map." Frequency along the y-axis, amplitude along the z-
axis, time along the x-axis. Of course, you'll need
some algorithm to "decide" when something bad is
happening with the bearings.
Regards,
Arlen Fletcher
--
"They that can give up essential liberty to obtain a
little temporary safety deserve neither liberty nor
safety." - Benjamin Franklin
> I am looking at the possibility of using some sort of vibration
> sensor, interfacing it to an A/D converter, and capturing the
> wave generated from a bearing.
>
> What I'd like to do is to sense when the bearing has some
> sort of fault, typically a spalled ball bearing or a faulty race.
>
> I am assuming that I would have to use the SX to get high
> enough sampling, but maybe someone who has some experience
> could help me out here.
>
> Thanx in advance......JP Harrison
>
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
website: Using the ADXL202 Accelerometer as a Multifuncion Sensor (Tilt,
Vibration and Shock) in Car Alarms, by Harvey Weinberg and Christoph
Lemaire. It includes high pass filtering for shock sensing.
Dennis
Original Message
From: Harrison, JP [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=CSA3OP9u1QgE7cXgb6tr76zlos4FK_btOHYCp9UEztorAgkU_3YlsNGggIFb441DQRsSS2Ud2xWhMPlbKhhrPGKczM0]jpharrison@n...[/url
Sent: Wednesday, February 21, 2001 1:02 PM
To: 'basicstamps@yahoogroups.com'
Subject: [noparse][[/noparse]basicstamps] Vibration
I am looking at the possibility of using some sort of vibration
sensor, interfacing it to an A/D converter, and capturing the
wave generated from a bearing.
What I'd like to do is to sense when the bearing has some
sort of fault, typically a spalled ball bearing or a faulty race.
I am assuming that I would have to use the SX to get high
enough sampling, but maybe someone who has some experience
could help me out here.
Thanx in advance......JP Harrison
Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
the ADXL202/SCXS210 with the Parallax Basic Stamp Module to Speed Algorithm
Devlopment, by Harvey Weinberg. It includes code for BS1 and BS2.
Dennis
Original Message
From: Harrison, JP [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=JgbL2csaLO_eXfjw2D_sYcoJmx2MYp2Zni2lGVFchNp6Gx6Jzum7nNS5f4akxFY-EWYI23C5sDUfeDjzae1o5cAIHfQjZi-7rw]jpharrison@n...[/url
Sent: Wednesday, February 21, 2001 1:02 PM
To: 'basicstamps@yahoogroups.com'
Subject: [noparse][[/noparse]basicstamps] Vibration
I am looking at the possibility of using some sort of vibration
sensor, interfacing it to an A/D converter, and capturing the
wave generated from a bearing.
What I'd like to do is to sense when the bearing has some
sort of fault, typically a spalled ball bearing or a faulty race.
I am assuming that I would have to use the SX to get high
enough sampling, but maybe someone who has some experience
could help me out here.
Thanx in advance......JP Harrison
Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>sensor, interfacing it to an A/D converter, and capturing the
>wave generated from a bearing.
>
>What I'd like to do is to sense when the bearing has some
>sort of fault, typically a spalled ball bearing or a faulty race.
>
>I am assuming that I would have to use the SX to get high
>enough sampling, but maybe someone who has some experience
>could help me out here.
The BASIC Stamp, even the SX, is not the right choice to do that directly.
Speed--you would be hard pressed to write a sampling loop fast
enough to meet the Nyquist frequency.
Memory--FFT and digital signal processing in general requires a
large RAM memory array
Computation--DSP requires a powerful number cruncher.
It is possible you could do something very effective on the Stamp
with preprocessing filters. For example, use analog or SC filters to
resolve the signal into several frequency bands, and then have the
Stamp look at the ratios. But what if the rotation rate changes;
then all the frequencies shift up? Lock into the fundamental
rotation frequency using a phase lock loop, and use that to clock the
SC filters. But I guess the point is, it would take some non-trivial
external hardware.
-- Tracy Allen
electronically monitored ecosystems
http://www.emesystems.com
interested in.
It was from Metrix Instrument Co. and is entitled "Vibration
Instrumentation." It has some technical information on vibration
measurement as well as various products that they sell. Metrix can be
contacted at: sales@m... (email) or 800-638-7494 (phone) or
www.metrix1.com (web site). Don't know how pricey they are.
On Wed, 21 Feb 2001 13:02:20 -0800 "Harrison, JP"
<jpharrison@n...> writes:
> I am looking at the possibility of using some sort of vibration
> sensor, interfacing it to an A/D converter, and capturing the
> wave generated from a bearing.
>
> What I'd like to do is to sense when the bearing has some
> sort of fault, typically a spalled ball bearing or a faulty race.
>
> I am assuming that I would have to use the SX to get high
> enough sampling, but maybe someone who has some experience
> could help me out here.
>
> Thanx in advance......JP Harrison
>
>
>
> Your use of Yahoo! Groups is subject to
> http://docs.yahoo.com/info/terms/
>
>
··· Carl·· see dot oddball dots martin
c.oddball.martin@worldnet.att.net
accomplish this. Please contact me directly @
dreamsystems@c...
~\/~
(@ @)
______ooO_( )_Ooo_______________________________________
"If we all did the things that we are capable of doing,
we would literally astound ourselves."
Thomas A. Edison
______oo0_____0oo_______________________________________
Sincerely;
Stephen Holt
http://the-interface.org/
Original Message
From: agarb@j... [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=NBNPje9cQh3gYjsq7jFk4tCPJe2_zgMeTivEfIKEN5VNtOgIli9FtRRvmq-gNQfn23e2dTUr764]agarb@j...[/url
Sent: Thursday, February 22, 2001 7:15 PM
To: basicstamps@yahoogroups.com
Subject: Re: [noparse][[/noparse]basicstamps] Vibration
The other day something was sent to me at work that I think you might be
interested in.
It was from Metrix Instrument Co. and is entitled "Vibration
Instrumentation." It has some technical information on vibration
measurement as well as various products that they sell. Metrix can be
contacted at: sales@m... (email) or 800-638-7494 (phone) or
www.metrix1.com (web site). Don't know how pricey they are.
On Wed, 21 Feb 2001 13:02:20 -0800 "Harrison, JP"
<jpharrison@n...> writes:
> I am looking at the possibility of using some sort of vibration
> sensor, interfacing it to an A/D converter, and capturing the
> wave generated from a bearing.
>
> What I'd like to do is to sense when the bearing has some
> sort of fault, typically a spalled ball bearing or a faulty race.
>
> I am assuming that I would have to use the SX to get high
> enough sampling, but maybe someone who has some experience
> could help me out here.
>
> Thanx in advance......JP Harrison
>
>
>
> Your use of Yahoo! Groups is subject to
> http://docs.yahoo.com/info/terms/
>
>
Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/