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Electronics => Projects, Designs, and Technical Stuff => Topic started by: ammjy on March 31, 2019, 03:37:37 pm

Title: Questions about Allan Variance for INS ( Gyroscope, Accelerometer )
Post by: ammjy on March 31, 2019, 03:37:37 pm

Hello, EEVBlog peoples !

Always Thanks you for your help.

in this moment, i should calculate the Allan Variance from logging data of INS to estimate error.

i recorded Gyroscope and Accelerometer, Temperature datas for 97 minute without any movement.

and now i following Matlab reference to obtain Tau-sigma graph.
( https://kr.mathworks.com/help/fusion/examples/inertial-sensor-noise-analysis-using-allan-variance.html )

Sampling time is 97.1061 minute. (from 91.98 sec till 5918.346 sec)
Total number(length) of data is 836185.

but, i can't understand what is a Fs.
Anyone know about it ?

i attached screenshot of page.
(That page support Example for that. but, unfortunately, my student version Matlab 2017b has not that example... )

Please, let me know !

Title: Re: Questions about Allan Variance for INS ( Gyroscope, Accelerometer )
Post by: awallin on March 31, 2019, 03:53:48 pm

Fs is the sample-rate, and its inverse t0=1/Fs is the time-interval between data points.

Title: Re: Questions about Allan Variance for INS ( Gyroscope, Accelerometer )
Post by: ammjy on March 31, 2019, 03:59:39 pm

Thanks you for your time, Awallin.

then, might be i can use recorded time data to sample rate FS !

Regard,
ammjy

Title: Re: Questions about Allan Variance for INS ( Gyroscope, Accelerometer )
Post by: awallin on March 31, 2019, 04:29:53 pm

Quote from: ammjy on March 31, 2019, 03:59:39 pm

then, might be i can use recorded time data to sample rate FS !

t0 = "recorded time 97mins" / "number of data points"
Fs = 1/t0

Title: Re: Questions about Allan Variance for INS ( Gyroscope, Accelerometer )
Post by: ammjy on April 01, 2019, 05:53:47 am

Good day, Awallin !

thanks to, i got result.

i appreciate for your kind help, again !