Hello,

for the purpose of my bachelor thesis I'm currently having a focus on inertial tracking/navigation.

I'd like to determine the position of an IMU in a defined space. Therefore I'm using a** ADIS16488 **with 3 accelerometers, 3 gyros and 3 magnetometers.

As I'm widely unexperienced in the field of inertial navigation, I have some problems to interpret the data of the magnetometers. I totally understand the data that I get from the accelerometers and gyros but I'll need some support with the magnetometers.

I guess the magnetometer works like a compass. So it is possible to determine the orientation of my IMU from the data of the 3 magnetometers, is that correct?

But how do I have to handle that data? E.g.: If I place the IMU plane on my desk and rotate the unit around its Z-Axis (YAW) in a certain angle, how do I get the value of that angle from my magnetometer data readings?

It would be great if someone could give me some hints.

Thank you in advance.

Regards,

Udo

Hello Udo,

The magnetometer will give you the magnetic field intensity on three orthogonal axes, so you can use geometric functions to compute the angles. For the situation that you describe, you would use the arctan(my/mx), assuming that all hard and soft iron errors in your environment are addressed. I did some Google searching on "magnetometer formulas" and came across this link.

www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA474475

I hope that helps.

Best,

NevadaMark