Hi everyone! I'm making a robot. 
This robot needs to be able to follow LIFE FORMS, (humans) but AVOID non-living things (walls, obstacles, etc) So, when it detects a life form it follows it, but when it detects a wall, it avoids it. I've been doing ALOT of research. I was thinking PIR sensors were the way to go, but the robot needs to be MOVING so that movement could interfere with the PIR detection. Any help please? And other ideas to try? Any help is really appriciated!
You should be talking with this forum poster.
jremington:
You should be talking with this forum poster.
Sorry, but I don't think that'll work for my purposes. You see, that is detecting human presence, rather that DIRECTION of the human.
Tough one.
I would have some kind of scanning IR thermometer and try to track the warmest spot in the room. But not too warm; you don't want your robot to become best buddies with the open fire.
MorganS:
Tough one.I would have some kind of scanning IR thermometer and try to track the warmest spot in the room. But not too warm; you don't want your robot to become best buddies with the open fire.
IR Themometer? Like that Sharp Distance Measure thing? Could you please give an example?
Isn't A PIR Sensor this already? Would a PIR sensor work?
NO, like the the thermometer you can point at any surface and measure the temperature of that surface from several meters away. "Laser Thermometer" is another name for the same thing.
So a laser thermometer is what I'm looking for?
Yes, but you'd need to find one with a digital output that the Arduino can interpret. Sometimes even the cheapest ones from Harbor Freight have that feature. You would have to search through a few forums to find people talking about the specific model numbers.
Or spend $200 for a commercial temperature sensor that comes with a proper datasheet and API.
Would this cheap little gizmo serve my purposes?
No. That looks like it's just a laser. I have no idea how that is related to temperature control.
Panasonic Grid-eye
How about this?
http://www.melexis.com/Infrared-Thermometer-Sensors/Infrared-Thermometer-Sensors/MLX90614-615.aspx
The MLX90614 sensors measure the average temperature of the entire field of view, which is rather broad for the standard sensor. They will detect humans a short distance away, if the sensor is pointing in the right direction.
However, you can buy the sensor with a narrow field of view option, so try it out!
AWOL:
Panasonic Grid-eye
This is GREAT! But, how can I use it with Arduino? It is perfect for my purposes, but interfacing it with Arduino? How could I do it?
Have a look at the support package, which includes Arduino source.
WesleyRTech:
Hi everyone! I'm making a robot.
Hire a stalker !
PID are not really suitable for you needs.
The likes of grid eye or spot IR temp detectors will require electromechanical optics and i would suggest that that is where the biggest problem is likely to lie.
But could this work:
http://www.robotshop.com/en/roboard-rm-g212-thermal-array-sensor.html
Or how about this: (This one would be SOO much easier )
Here's another thermal imager option.
The Roboard PCB uses a sensor like this one. It's mounted on a PCB with some support components. Make sure you take a look at the datasheet to see how to interface with it. It's my understanding there's a lot of math involved converting the data to useful temperature information. It might not be too hard to figure out which areas are warmer than others but I think getting exact temperatures takes a lot of work.
WesleyRTech:
How about this?
I think the above mentioned sensor is a good match for the task. I think they sell the sensor with various fields of view. A narrow field of view might be useful for locating the person.
Boardburner2:
The likes of grid eye or spot IR temp detectors will require electromechanical optics and i would suggest that that is where the biggest problem is likely to lie.
What do you mean by "electromechanical optics"? A servo to scan the area?
I once tried to purchase some GridEye chips but I didn't pass the review process. Using it with a robot to search for someone (elderly), who may have fallen and needs help, didn't cut it.
I imagine the requirements to purchase one now might not be as tight as it had been a couple years ago.
I was allowed to purchase the Melexis 4x16 sensor. I'm not sure why one could be sold without additional paperwork while one couldn't.
Whichever solution you chose, you should probably find some example projects showing how to get the data from the sensor. It's not always a simple process.
Early stinger missiles used four LDR.
I suspect these would make it easy, probably restricted for those sort of reasons