tlocus

Hello,
A few years back I built a wheelchair robot that had ping sensors, bumper sensor, a microsoft Kinect (PC version) for the 'head'
I could have it roam around avoiding obstacles, people. the ping sensors were aimed left, right, front and back. So when the robot encountered an obstruction, it would check all ping sensors and pick the one that had less or no obstructions.
The furthest I was able to get with it was with a Microsoft kinect sensor for PC to follow me (I wore a red shirt). It would follow me around if the distance to me was greater than some value it would 'catch' up to me. If the distance was less than/equal to 2-3 feet it would slow down or stop if I stopped...

I'm doing a quad build and was wondering what options I have now. I've seen some commercial quads that have software that 'detects' a person and or their outline? What about have some sort of signal... like possibly an Active RFID?

any suggestions would be awesome
t