I am building 4-wheeled, knee-high robot with music and speakers on top that will follow a target person as the target moves around. I would like some help with the setup for tracking the target. The most obvious solutions are Ultrasound or Infrared sensors or some kind of vision tracking, but for this application, I don't want to use them.
Imagine that the robot is placed into a crowded area and asked to move towards a particular person in the area (for the sake of simplicity, assume the person is less than 5 meters away, but could be obscured by an object). Ideally, if someone walked between the target and the robot, the robot would not lose it's path (as would happen with vision-based sensing).