Its a very simple and easy to make follow me robot. It can sense the presence of object to be followed using Infra-Red ( IR ) sensor. There are one IR Led and two IR photo diode (with back IR Filter) . When the IR gets reflected from a nearby object and back to both the receivers diode, the transistor based switches power ON both the motors and the robot moves forward. If the object moves left or right then any one motor gets switched on and the robo takes turn.
Step 1: Step by Step Video Instructions to Make It
Here is the video link to make it . Video
There is no micro-controller was used. Very simple circuit. Hope you will enjoy the making.