Limits of Functions alignsigna​l/finddela​y/xcorr - Need help aligning signals

Hey :)

I am trying to align multiple signal so i can compare them.

https://drive.matlab.com/sharing/ba946f41-48b1-42e0-8492-7ff8c859fc10 (Zip with 2 signals as .mat files)

I tried using xcorr/alignsignals and finddelay. But it seems like these functions are not able to find the delay. Both signal where recorded on different systems, but they do have the same sample frequency.

Do you have any suggestions? Are there other options to accomplish this task?

Thanks :)

Answer 1

[Githin George]

Hello Alex,

It is my understanding that you are trying to align multiple signals so that you can compare them.

You can use the “alignsignals” function in Signal Processing Toolbox to estimate the delay between two signals and obtain the aligned signals as well. In addition, you can use the Signal Analyser App in MATLAB to visualise the original signals and the modified ones to ensure you obtained the correct results.

You can take a look at the example code below , where I am comparing the signals from the two provided MAT files.

load signal1.mat
load signal2.mat

X = eul_robot(:,3);
Y = euler_madg_6dof(:,3);

[Xa,Ya,D] = alignsignals(X,Y);

The variable “D” contains the number of samples by which “X” and “Y” are offset.

Please have a look at the documentation of “alignsignals” function for details.

https://www.mathworks.com/help/releases/R2021b/signal/ref/alignsignals.html#buvrt30-1-D

I hope this helps.