问题
Normally rotational data from the gyroscope y axis is updated with respect to vertical orientation of the phone. But if this orientation slightly changes as shown in the diagram, is there any method that i could take the component of y rotation to vertical axis(Vertical orientation position of the phone), ( This is possible for linear components by using Cosine angles sine angles) But what about rotation? Anyway i can we do this?
回答1:
To my experience, gyroscope's values are mobile, meaning that the axis are updated as rotations intervene (that's true for Android, no reason not to be for iOS).
If you want to keep an eye on your 3 axis directions, you'll have to keep updated a rotation matrix :
Direction Cosine Matrix IMU : Theory
Euler angles and DCM
来源：https://stackoverflow.com/questions/11106102/update-rotational-data-from-the-gyroscope-with-respect-to-a-predefined-orientati