Just researching ideas for a docking station for an arduino robot, like the idea of modulated beacon, my problem is translating to modern electronics, (my training was in discreet components 55 years ago! So 2 remaining brain cells take a while!!!

Moderator edit: New thread created from old one.
https://forum.allaboutcircuits.com/threads/using-an-ir-transmitter-as-a-beacon-for-a-robot.147129/

 

I am building a tracked robot which similarly needs to find its charging station. It is fitted with a magnetometer and notes the compass direction while it is docked and it has a phototransistor in a tube to limit its field of view. Then it can rotate on the spot to find the highest signal from the beacon and note the compsss direction. Then it can calculate which way to go to get on a line approaching the beacon at the correct angle. Then repeat this process as the robot nears its destination.