Loop Closure

You need loop closure to correct for the error when you do SLAM.

In practice, when a loop is detected, what this is doing under the hood is merely adding an edge to the Pose Graph.

There are multiple solutions:

• Identical positions (e.g. $x_6=x_1$)
• Scan matching (similarity)
• Features — not practical in real systems because it works in $O(N^2)$