How to use wavelet transform in vibrational signals?

plzzz....show the explaination of wavelet transformation in vibrational signals and also help me in understanding the waveforms......................

I am not a wavelet expert, yet I would experiement with the example in the application LLB for engine knock. In general wavelets are used to extract impact events in vibration signals.
Do you have a data file of your vibration data? What are you hoping to detech?
Preston Johnson
Principal Sales Engineer
Condition Monitoring Systems
Vibration Analyst III - www.vibinst.org, www.mobiusinstitute.com
National Instruments
[email protected]
www.ni.com/mcm
www.ni.com/soundandvibration
www.ni.com/biganalogdata
512-683-5444

Similar Messages

Continuous wavelet transform of vibrational signals (scalogram)

Hello to everyone,
I am a beginner in signal processing and I'm trying to perform a CWT of a vibrational signal, took on a IC engine, in order to better understand the differences existing with the time-frequency rappresentation. I performed the scalogram, but i do not understand why on the time axis i read wrong informations, that is, there are wrong values on the time axis. Is there anyone that can help me?
Thanks to all.
Attachments:
Scalogram.png ‏51 KB
Scalogram VI's front pannel.png ‏184 KB

Thanks for the answer,
I mean that i don't see the time values of the signal's time history.
Are they the traslation factors used to perform the CWT?

How to use the transformation matrix in Placed Suite.

I am in trouble how to use the transformation matrix Placed Art (PlacedSuite ).
       AIRealMatrix rasterMatrix;
AIRealMatrix placedMatrix;
if (artType == kRasterArt {
     error = sAIRaster-> GetRasterMatrix (art, & rasterMatrix);
} else if ((artType == kPlacedArt) {
     error = sAIPlaced-> GetPlacedMatrix (art, & placedMatrix);
When I converted to using the transformation matrix of PlacedArt, the target art could not be converted to expect.
I could convert in case of the RasterArt. (The reference point of the transformation matrix of RasterArt is (0,0).)
In the PlacedArt, preference point is not (0,0)?
The tx/ty of the transformation matrix of PlacedArt is not correct?
In the transformation matrix of RasterArt and Placed Art, how are those two different?

The short answer is "no", (0, 0) is not the origin of placed art (unlike kRasterArt). Off the top of my head, I believe when you place art, its original state is upside-down and flipped horizontally in the upper-right of the artboard. If you want to see where it starts, simply create an identity matrix and apply that as the matrix for the kPlacedArt and you'll see how it starts. Yes, its pretty crazy.
minimum99 posted some code that might help. I haven't tried it (I rolled my own years ago) but I'd give it a whirl:
http://forums.adobe.com/message/3195790#3195790

How to use wavelet analysis in labview 8

Dear everybody
how can i use wavelet analysis in labview 8
thanks in advance

Hey khairy,
There's quite a bit of information available at ni.com about wavelet analysis and how to perform this in LabVIEW. By just doing a quick search, I came up with the following links:
NI LabVIEW Advanced Signal Processing Toolkit:
http://sine.ni.com/nips/cds/view/p/lang/en/nid/1395
Advanced Signal Processing Toolkit Demo:
http://zone.ni.com/devzone/cda/epd/p/id/4765
KnowledgeBase Articles:
Custom Wavelet Analysis Using Signal Processing Toolkit in LabVIEW
http://digital.ni.com/public.nsf/allkb/11ABBF34A0D8E9BB86256E55005CA69D?OpenDocument
How Do I Use the Continuous Wavelet Transform to Produce a Scalogram?
http://digital.ni.com/public.nsf/allkb/79EABCEBCA56F65686256F340062C4D7?OpenDocument
Good Luck!!
Brian B
Field Sales Engineer
Tennessee/Southern Kentucky
National Instruments

Question on the result of using Wavelet transform on sine wave

Dear all,
I have apply the Wavelet transform on a 50Hz sine wave. The result is shown below. But I don't understand the result of Wavelet transform. Anyone can help me? Thanks.
Victor

You seem to have something against the FFT, yet continually compare other transforms to the "sweet spot" for the FFT, ie. sinusoidal and periodic functions. Without trying to write a treatise on the subject (there are many fine books), a few observations.
The primary purpose of any transform pair is to perform a rotation in function space, for the FFT we are familiar with the time domain and frequency domain. The wavelet domain is not so simple. The FFT is very effective for sinusoidal and periodic functions, ie. those that have no localization in the time domain. If you have a sinusoidal input, the infinite signal in the time domain can be reduced to a pair of numbers (one if you take the power spectrum). That is very efficient, other periodic signals can usually be approximated by a small number of terms.
Wavelets on the other hand are chosen to be localized in both the time domain and the wavelet domain. If you look at a periodic signal like your sine wave, you see a mess, and to recreate the input signal you will need to keep an awful lot of the points around for the inverse transform. You may be able to set the last 1/3 to zero, but that's it. To see an effective application, you should be looking at localized functions, like an impulse. Put an impulse into the wavelet transform and you get something that is still a bit complex, but pretty simple. The FFT of an impulse contains components at all frequencies and the wavelet clearly wins in this case.
On paper, there is usually a clear choice, and the FFT almost always wins for spectral estimation. On the other hand, if you are trying to compress "real world" data, for instance an image, then there is a choice to be made. Standard JPEGs are FFT based, you take the FFT and try to keep just the largest frequency components. As you probably notice, edge contrast usually suffers, especially at higher compression. With wavelets, it is typical to have slightly better contrast leading to better preservation of details for a given compression.
In short, my opinion is that transforms are useful when they simplify the problem. Wavelets do not simplify the representation of a sine wave.

How to use the transformation file

Hello there!
This message is to ask a question that maybe it could be familiar to you. I want to load data using a .txt file and a transformation file using the import package. Suppose that the structure of my txt file is:
Entity,Category,Time,Account1,Account2,Account3
Ent1,Actual,2010.JAN,289.23,32.43,123.34
Ent1,Actual,2010.JAN,289.23,32.43,123.34
Ent1,Actual,2010.JAN,289.23,32.43,123.34
How could I load this values using a transformation? I know that there exists an option named *MVAL(), but if I use the following syntax in mapping section it doesnu2019t work:
Account=*MVAL(4:6)
I read something about accountval, does some boddy knows how to use it?
Thanks in advance
regards

Hi,
If you are using MVAL statement, then you need to maintain a conversion file also. Its compulsory. Please make sure that you have maintained a conversion file.
If you are on 7.5 MS, then the statement will work. Please refer to the MVAL statement in the mapping section of the below link
http://help.sap.com/saphelp_bpc75/helpdata/en/a2/e722bc58404335ada8592cdc8feaca/content.htm
However, in 7.0 MS, the MVAL works only if the multiple key figures are corresponding to the time dimension. In your case, they correspond to the account dimension. You need to create separate transformation file for each of the key figures and then upload the flat file separately using each of the transformation files.
Hope this helps.

How to use joiner transformation for 3 sources?

Hi,
I want to use joiner transformation to join my 3 source tables (t1, t2, t3).
When I look at the joiner transformation it only has INGRP1 and INGRP2 for two sources. How do I use it for third source for joining? I dont see INGRP3 so that I could drag my third source in to the joiner.
Regards,
Billu

Can also break the join down into a number of joins which has advantage sometime if part of the join can be reused or you want to (in 11gR2) use different data movement technology for that set of operators. There are 2 illustrations here one with 2 joiners for 3 tables the other with one joiner which has 3 groups;
!http://blogs.oracle.com/warehousebuilder/owb_join_expressivity.jpg!
Cheers
David

Would like to use Wavelet Transform functions

Hello:
As the title says, does Measurement Studio has wavelet transform functions. I currently have version 6.0 (full) and version 7.0 (have not used it since I am still on VB6). Thanks.
Raj

Hi Raj,
There isn't any particular "Wavelet Transform" method available in
Measurement Studio at this time. For a complete list of analysis
functions for the various versions of Measurement Studio, check out the
following link:
http://www.ni.com/analysis/cwtools_analysis.htm
Thanks Raj, have a good one!
Dan Weiland
Applications Engineer
National Instruments
www.ni.com/support
Dan Weiland

How to use a transformer xml to html

hi
I want to develop jsp pages based on xml data, so to construct components with xml data i must use a transformer converting xml to htm. so if there is a better or more generic solution of classes or examples that can help me , i tried to use cocoon but the problem was to use it within a jsp page.
please to mail me your suggestions or solutions .
thank you

Review Xalan/Xerces from the Apache project.
http://xml.apache.org/xalan-j/index.html
http://xml.apache.org/xalan-j/usagepatterns.html#servlet
http://xml.apache.org/xalan-j/samples.html
Just one method...

How to use 2 transformator in a single application?

Hi,
We have an application which uses jars from many vendors, one jar needs to use Saxon.jar, another needs to use platform default transformer instance.
We are able to set only one in javax.xml.transform.TransformerFactory property.
Please help!
Regards,
Aparajith

I tried to use like this. i did not know what is the platform default instance.
try {
             System.setProperty("javax.xml.transform.TransformerFactory ",
                       "org.apache.xalan.processor.TransformerFactoryImpl");
            TransformerFactory transFactory = TransformerFactory.newInstance();
            Transformer transformer = transFactory.newTransformer();
             //TransformerFactoryImpl transFactory = new TransformerFactoryImpl();
             //Transformer transformer = transFactory.newTransformer();
            DOMSource dSource = new DOMSource(node);
            StringWriter sw = new StringWriter();
            StreamResult sr = new StreamResult(sw);
            transformer.transform(dSource, sr);
            StringWriter anotherSW = (StringWriter) sr.getWriter();
            StringBuffer sBuffer = anotherSW.getBuffer();
            processedXML = sBuffer.toString();
        } catch (Exception ex) {
             ex.printStackTrace();
             throw new Exception(" Failed to convert XML to string.:: "+ex);
        return processedXML;Thank you for your responses.
Regards,
Aparajith

How to use OAF transform sotred xml documents using XSLT...

Does anyone have any experience using XSLT in OAF? Specifically, I have xml documents stored in a clob to which I wish to apply an XSLT transformation and then store the transformed documents back into the clob. Is there a way to apply an XSLT transformation using say BI-Publisher via OAF?

"XML DIFF" are the keywords you can use to search for products that do this. Last time I looked there was a lot of XML Diff implementations, but none of them produced human-readable output that I really liked. I expect that's because XML diff is an easy thing for people to ask for but not an easy thing to do, given the considerable number of ways there are to change a document.

How to use WB_IS_NUMBER Transformation?

Hi,
Presently i am evaluating OWB 9i. I am trying to migrate records from flat files to oracle db. While migrating i would migrate records which are having valid numeric values in particular field. I tried with WB_IS_NUMBER funtion and number is default. I could not succeed. Please can anyone help me out.
Thanks in Advance.
Siva.

The actual syntax of the function in OWB seems to be incorrect (at least I did not get it to work either). I will log a bug for that.
To fix the problem you can create your own function in OWB and use the following logic:
create or replace FUNCTION Is_Number ( p_var VARCHAR2, p_format VARCHAR2 := null )
RETURN varchar2
IS
p_number NUMBER;
BEGIN
if (p_format is null) then p_number := TO_NUMBER(p_var);
else p_number := TO_NUMBER(p_var, p_format);
end if;
RETURN 'TRUE';
EXCEPTION
WHEN OTHERS THEN RETURN 'FALSE';
END Is_Number;
THis will return TRUE if this is a number otherwise it will return FALSE. You can of course modify to give you the value back as well in the case of TRUE.
Jean-Pierre

How to use a function in OWB 11.2

Hello all,
I need help running an Oracle function in OWB 11.2
I have created and defined the parameters of the function within the design center by right clicking on function, new from the Projects Explorer window. I have also validated the Function and it was successful. I have also tested deploying the function to the database successfully.
My question now is how do I implement it? ie how do I run it? the function is actually supposed to derive a column and load it into another column on the same table based on a condition
Do I drag and drop it within the mapping? and link it? please help me!
thanks so much
IP
Here is the code of the function:
CREATE OR REPLACE FUNCTION "LD_EMPL_FOR_CITY"("EMP_STATE" IN VARCHAR2, "EMP_ADDR" IN VARCHAR2) RETURN VARCHAR2
IS
BEGIN
IF EMP_STATE = '. ' THEN
RETURN EMP_ADDR;
ELSE
RETURN NULL;
END IF;
END;
/

Thanks MKO.
I dragged the function into the mapping and connected and it worked.
I wish ORACEL can be a little bit more specific in it's documentation. I do not see where on how to use these transformations.
Thanks again!

How to find the phase difference between two signals using Hilbert transform

hi,
I am new to LabView.... I am trying to find phase difference between two signals. I sucessfuly found out the phase difference between two predefined waves using single tone measurement. .... But I really want to know how can I measure phase difference between two signals( not predefined... ie we don't know the initial conditions) using hilbert transform or any transformation techniques (without using zero cross detection).. I tried by using hilbert transform based on algorithm... bt I am getting error.... plz help me
Attachments:
phase_differece.vi ‏66 KB

you could try something similar to this, for each table pair that you want to compare:
SELECT 'TABLE_A has these columns that are not in TABLE_B', DIFF.*
FROM (
        SELECT COLUMN_NAME, DATA_TYPE, DATA_LENGTH
          FROM all_tab_columns
         WHERE table_name = 'TABLE_A'
         MINUS
        SELECT COLUMN_NAME, DATA_TYPE, DATA_LENGTH
          FROM all_tab_columns
         WHERE table_name = 'TABLE_B'
      ) DIFF
UNION
SELECT 'TABLE_B has these columns that are not in TABLE_A', DIFF.*
FROM (
        SELECT COLUMN_NAME, DATA_TYPE, DATA_LENGTH
          FROM all_tab_columns
         WHERE table_name = 'TABLE_B'
         MINUS
        SELECT COLUMN_NAME, DATA_TYPE, DATA_LENGTH
          FROM all_tab_columns
         WHERE table_name = 'TABLE_A'
      ) DIFF;that's assuming, column_name, data_type and data_length are all you want to compare on.

About Vibration analysis of machine using wavelet analysis and extraction techniques

I want to perform vibration analysis using accelerometer and NI DAQ please help me in VI development and how and which parameters should i extract from the raw signal. About Vibration analysis of machine using wavelet analysis and extraction techniques.
Nitesh Parmar
+91-9780900184
[email protected]

Lynn,
Thanks for the reply.
I'm attaching some pictures of the test rig. As you can see, we have a small servo motor sitting on top of the bearing, which is a small needle/thrust bearing, used in the planetary gears of automatic transmissions. The readings are being taken by a general purpose 100mV/g accelerometer, which you can see is mounted on the bottom of a fairly thick steel plate. I understand there can be some transmissibility problems when going through too much material? We seem to be getting a reading though. The only weight on the bearing is the motor and mounting plate, 5-10lbs. I considered adding weight, and that will probably be my next move.
I'm also attaching some runs I've made. One set is of a brand new bearing, the other set is of one I stuck in a sandblaster. It is now very obviously damaged, rough and noisy when you turn it. You should be able to open these files with the .vi attached to my previous post. The first tab will be the waveform, raw data. It is not accurately calibrated to g's, but I think it should be in the ballpark. The runs are comparable to each other anyway.
I'm not currently alligning the readings with the motor revolution. Maybe this is something I should look into? I have a very capable motor/drive setup for this...
I was previously using a legacy daq device, with which I couldn't wire the error lines into the digital line write tool. You are correct that I can now remove the while loops.
Whatever else I can provide to help you assist me here, let me know.
Thanks for the feedback.
Jeremy Backer
CLAD
Attachments:
Bearing Pics.zip ‏898 KB
Brand New.zip ‏3429 KB
Sand Blasted.zip ‏3426 KB

How to use wavelet transform in vibrational signals?

Similar Messages

Maybe you are looking for