Sensor options for following a person outdoors

[Keithh28]

Ok, I know that getting a robot to follow a person around is something that can be done numerous ways, but I'm wondering if anyone has experience using these techniques outdoors in various light conditions?  I'm designing a large 'bot that can follow someone around a yard, like a wagon carrying stuff.

I'm thinking that the simplest method would be to make a small clip on IR LED module that would "strobe" a pre-set pattern, which the bot could follow like a photovore. My question is this...do you think such a system would be reliable even in bright sunlight?  Also, are there any particular software or hardware techniques to prevent "confusion" if the IR light gets reflected off another surface, such as glass, water or metal?

I'm willing to entertain other options if you want to suggest them, but I am a novice programmer and want to keep it simple. I would also prefer a system that works at night without being obnoxious...I.e. I would prefer not to use visible strobes. The platform will be a 6 wheeled differential drive bot, a simple box approximately 18" x 18" x 38"...plenty of battery power and plenty of room for sensors. 

I appreciate any advice you might have!


Keith

[greywanderer012345]

   IR definitely still works in bright sunlight. My son has a few toys that are IR remote controlled, rather than radio. Oh, and as I wrote that, I remembered that I have an Air Hogs helicopter that is IR remote controlled. They all work just as good outside as inside.

   You might also want to look at the robot vision tutorial here. However, camera=expensive, and wearing a beacon is better than requiring some specific colored shirt or something.

[waltr]

The 'trick' with IR remote control, or just detection, is to modulate the IR LEDs. Then use an IR modulation detector (Receiver). This is have IR TV remotes work and the receivers are cheap and readily available.
Just google "IR remote receiver chip".

[Keithh28]

   You might also want to look at the robot vision tutorial here. However, camera=expensive, and wearing a beacon is better than requiring some specific colored shirt or something.

That's what I was thinking. I wouldn't mind adding robot vision in the future, but I need to learn a lot first. I'm looking for something simple and inexpensive right now.

The 'trick' with IR remote control, or just detection, is to modulate the IR LEDs. Then use an IR modulation detector (Receiver). This is have IR TV remotes work and the receivers are cheap and readily available.
Just google "IR remote receiver chip".

Thanks for the suggestion, I appreciate it. Any idea what my range might be in sunlight with such a device?

[waltr]

The range should be equal to or greater than the range of your TV remote.
If you need greater range then use more powerful or multiple IR LEDs.