Timeline for Damped sinusoidal form FFT of signal
Current License: CC BY-SA 4.0
14 events
| when toggle format | what | by | license | comment | |
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| Oct 13, 2018 at 9:31 | vote | accept | CommunityBot | ||
| Oct 13, 2018 at 9:31 | comment | added | user38162 | @DanBoschen thanks for your explanations. I'll take it in consideration. | |
| Oct 12, 2018 at 2:25 | answer | added | Dan Szabo | timeline score: 1 | |
| Oct 12, 2018 at 1:55 | comment | added | Dan Boschen | Tones in frequency are repetition in time, within the time of your capture (and from the time domain view, I do not see any such repetition, and the frequency view would indicate if there indeed was something at much smaller values than we can see. What can help you is to window your time domain function before taking the FFT (to reduce sidelobes of your stronger components in frequency masking the weaker ones), and you can also zero pad the time domain function by adding a lot of zeros before taking the fft to interpolate more freq samples (will only make the plot prettier, not add info) | |
| Oct 12, 2018 at 1:53 | comment | added | Dan Boschen | What you are seeing is reasonable and expected. You would get the plot in your referred jpg if you had strong content that existed at very specific frequencies. From your FFT it looks like that is not the case and I am not sure why your experiment would result in such tones. Otherwise you are seeing the dominant effect of your rectangular pulse which is a Sinc in frequency (which you could describe as a decaying sinewave), | |
| Oct 11, 2018 at 22:22 | comment | added | user38162 | Is there any wat to get the fft more like a plot like this? i.sstatic.net/jeIDT.jpg | |
| Oct 11, 2018 at 20:31 | comment | added | SignalProcessingJobs | It still looks a little strange. But the damped sinusoid (sinc function) is caused by using a rectangular window in the time domain which translates to a sin(x)/x function in the frequency domain. | |
| Oct 11, 2018 at 20:28 | comment | added | user38162 | The assignment was to analyze the current signals generated during short-circuit welding. I'm filtering the data using a Wiener filter (nl.mathworks.com/matlabcentral/fileexchange/7673-wiener-filter). I've added the code above. I've also added an image of the signal before and after filtering. | |
| Oct 11, 2018 at 20:27 | history | edited | user38162 | CC BY-SA 4.0 |
added 139 characters in body
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| Oct 11, 2018 at 20:21 | comment | added | Basj | @Jost Please edit to include the images directly in the question, it will be easier for readability. | |
| Oct 11, 2018 at 20:20 | history | edited | user38162 | CC BY-SA 4.0 |
added 488 characters in body
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| Oct 11, 2018 at 20:15 | comment | added | SignalProcessingJobs | please provide the code you used to generate this and the data. Also, how are you filtering the data and what is "welding"? | |
| Oct 11, 2018 at 20:15 | review | First posts | |||
| Oct 12, 2018 at 13:48 | |||||
| Oct 11, 2018 at 20:11 | history | asked | user38162 | CC BY-SA 4.0 |
