- world coordinate system
- ego-vehicle coordinate system
Rigid Body is a solid body in which deformation is zero or so small it can be neglected.
rigid body assumption implied that movement of a sensor mounted on the robot should be the same as other co-located sensors and the whole platform.
Motion that can be described by a rotation and translation. There are 6 degree of freedom (DoF) in 3D space for rigid body.
Direct Cosine Matrix (DCM), unit vectors, 3 assumptions
Euler Angles, single axis rotation, in an intrinsic sequence (X, Y, Z).
Gimbal lock, loss of one DoF, cause singularity.
Order of rotation, rotation in 3D are non-commutative.
North East Down (NED) frame
Global Positioning System
Position in ECEF coordinate via accurate ephemeris information. Time of signal transmission via onboard atomic clock.
Reducing uncertainty every time we add a new circle.
In this case we have sphere.
Ephemeris & clock errors, Multipath effect affecting precision
- Understanding Direct Cosine Matrices, Euler Angles and Quaternions.
- Representing Robot Pose: The good, the bad, and the ugly.
- Rethinking GPS: Engineering Next-Gen Location at Uber