Framing things

[JacobAMason]

Make sure that the map frame and odometry frame are correct for use with the nav stack -Billy

• Make sure the frame labels are correct. Specifically, the ArUco and beacon pose topics.
• Generate a transform between the map frame and the odom frame.

There are two main frames, the map and the world. These are fixed.
There are base_link and odom frames.

• Base_link is the robot; it's a local frame of reference.
• Odom is semi-fixed. Odom is locally continuous. Whenever you make movements, the odom will be continuous, which is necessary for path planning.

The odom frame is built from IMUs and motor encoders. Error starts to accumulate, but it's continuous. GPS and ArUco are put in a different frame because they aren't continuous and will screw up continuous frames (like odom). ArUco functions really similarly to a GPS.

Robot Pose EKF can take an arbitrary number of poses and velocities, both continuous and noncontinuous sensors, and return a single pose.