Coordinate Frames and Notation
Rovio makes use of various coordinate frames:
- W: the inertial coordinate frame employed by the EKF.
- M: the coordinate frame attached to the IMU
- C: the camera coordinate frame (optic center, z is along camera axis, x/y span image plane, x right, y down)
- V: Reference body coordinate frame if external pose measurements are employed
- I: Reference inertial coordinate frame if external pose measurements are employed
An overview is given in the following drawing (courtesy of Bharat Tak)
- qAB: represents the quaternion rotating a vector from coordinate frame B to A, Hamilton-convention
- ArAB: represents the coordinate of a vector from A to B expressed in coordinate frame A