Estimating phase difference in time and frequency domains
Here, you can find information on how to estimate phase difference between two signals recorded from DAQ.
What you need
- Signal measured from Laser displacement sensor(s) or force sensor
- See the pages for Laser displacement sensor(s) or force sensor to learn how to use the instruments and measure the data
- MATLAB codes
Watch this video first
Watch this video to learn how to obtain an estimate for phase difference in frequency domain. Note that estimating phase from FFT is not suitable for FSI applications even though it might be common in other applications.
Watch this video to learn how to obtain an estimate for phase difference in time domain or using Hilbert transform. Note that this technique is more suitable for FSI application.
Watch this video to learn how to obtain an estimate for phase difference using wavelet transform.
- Coming up!
Additional instructional videos:
Watch this video to learn more about signal representation in Time vs Frequency domain
Watch this video to learn more about Phase and Frequency Modulation
Watch this video to learn more about Hilbert transform
- https://youtube.com/playlist?list=PL_-64C59jLZqIWaUySuxz3RkNRI0fyIUI
- https://www.google.com/books/edition/Hilbert_Transform_Applications_in_Mechan/SrxInm2Kz_IC?hl=en&gbpv=0
Read more
Require wavelet toolbox or MATLAB 2021b and above version
- https://www.mathworks.com/products/wavelet.html
- https://www.mathworks.com/help/signal/ug/hilbert-transform.html
- https://www.mathworks.com/help/signal/ref/instfreq.html
- https://www.mathworks.com/help/signal/ug/hilbert-transform-and-instantaneous-frequency.html
- https://www.mathworks.com/help/signal/ug/envelope-extraction-using-the-analytic-signal.html
- https://www.mathworks.com/help/signal/ref/mscohere.html
- https://www.mathworks.com/help/signal/ref/cpsd.html
COMMON QUESTIONS: