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I have been using an accelerometer and I have realised that it was sitting at a tilt of 18 degrees in the z direction and rotated at 5 degrees in the x y direction. How should I change my accelerometer readings to account for this?
You should be able to multiply each of your readings by the cosines of the known error angles.I have been using an accelerometer and I have realised that it was sitting at a tilt of 18 degrees in the z direction and rotated at 5 degrees in the x y direction. How should I change my accelerometer readings to account for this?
This will not preserve the magnitude of the acceleration vector, which should be preserved in a mere rotation.You should be able to multiply each of your readings by the cosines of the known error angles.
My bad....they should be DIVIDED by the cosines...since being out of alignment will make the measured readings smaller.So for example my z reading will be multiplied by cos(18) and cos(5) as will the x and y readings?
The magnitude of the vector will be the same so the absolute components cannot be all smaller.My bad....they should be DIVIDED by the cosines...since being out of alignment will make the measured readings smaller.
Construct a 3x3 rotation matrix, that transforms the acceleration vector from the accelerometer coordiante system to the system you need:How would you approach this problem A.T?
Don't mess around with angles, then you have no problem with their order.I had already come up with a rotation matrix before but had considered the rotations in the wrong order.
I don't think this sufficient info to get a unique 3D rotation.As a result the only thing I have to go on is the x y z readings when the animal was stationary in order to work out how much the gyroscope had rotated and then correct the rest of the readings. So what I found was that at rest my readings were x = -0.9 y = 0.14 z = 0.44 and so I am trying to adjust the rest of my readings based on this info