I can't find out the response so I am posting here.
My post kind of follow this one : Adding magnetic field vector to a Kalman filter but I already know that I don't have to put the magnetometer in a state vector.
I am working on a implementation of an Extended Kalman filter. So far I have integrated a gyroscope, an accelerometer and encoders wheels.
But I don't know what are the equation for the update state to integrate a magnetometer.
So far :
I have seen some kind of work where magnetometer are fuse with accelerometer. But I don't have any formulas and I am kind of stuck...
I have seen some kind of work where there is no quaternion but I can't afford this modelisation cause of gimbal lock and I have all my work already in quaternion...
Thanks in advance for help. Don't hesitate if you need complementary details.