I got a nice opportunity to develop autonomous docking software for a differential wheeled robot. I have open sourced my work in GitHub along with essential documents. It will give a good idea for anyone who head start with autonomous docking on robot with minimal sensors.
The robot docks to a charging point autonomously when the charge in the battery drops below 20%
ROBOT DOCKING IN ACTION
ROBOT DOCKING VIDEO
There is one main state machine and 4 sub state machines designed for this project. Only the main state machine is displayed here. Checkout GitHub for more details on sub state machines.