Accelerometer and gyroscope mixed up

[RobotPsykolog]

Hello.

I recently bought a Muse S headband and have then just started to experimenting with it. Really like Mind Monitor and the big amount of data I can get out from it!

But now I am doing some testing with accelerometer and gyroscope. And in my humble opinion, these values is mixed up. Accelerometer data should be gyro-data and vice versa.

Gyro_plot.png (44.64 KiB) Viewed 1456 times

Acc_Plot.png (49.54 KiB) Viewed 1456 times

[James]

I'm not sure why you think that they're mixed up, but no, they're not.

You can clearly see acceleration due to gravity in the Accelerometer graph, changing between X, Y and Z as you orient the device.
Where as the Gyro has areas which show ~0, which (if it was actually accelerometer data) would only be possible in zero gravity... and I'm guessing you recorded this on earth?

[RobotPsykolog]

Hi James.

Thank you for you answer and your fast response in here. As I said. Really like your program.

I actually do not have so much experience in this. But in my opinion that might be wrong, the reading from the accelerometer, measure the sudden acceleration. That means a high spike, as it is seen in Gyro curve. Then when the movement is zero again, movement is stopped, it goes back to zero. No more movement.

The Gyro on the other hand, is a measurement on a position. If I turn my head in some way, it measure a location and stays there, as the acceleration curve views. This is what makes me believe they are switched. Please correct me if I am wrong. I wrote this in a rush before going to work today. Will look deeper into it now.

Kind regards

/Björn

[RobotPsykolog]

I have now looked at some "gyro graph" picture search and "accelerometer graph" picture search, at Google. It seems to be as I am mention above. The acceleration gives a sudden peak, when a sudden move, then moves back to zero again. And the gyro holds its position until the movement goes back again.
The reading from Muse is as my pictures shows. Am I really that wrong?

[RobotPsykolog]

The plot in "Accelerometer" in my pictures, show clearly a turning of my head laying down, in axis Y, yellow line.
This correlate with the sudden move in the gyro picture, when I START and STOP moving my head. Then goes back to zero when my head is still in a steady position.

[James]

The plot in "Accelerometer" in my pictures, show clearly a turning of my head laying down, in axis Y, yellow line.
This correlate with the sudden move in the gyro picture, when I START and STOP moving my head. Then goes back to zero when my head is still in a steady position.

There is no point in your Accelerometer image above where all axis are at zero.
I assure you that the Acc/Gyro are the correct way round

https://mind-monitor.com/Technical_Manu ... p_acc_gyro

[RobotPsykolog]

Ok. Thank you James, then it is my limited knowledge about this that makes me wonder. So I need to dig deeper. =)