# Can I make an automatically-parking robot car with IR sensor?

It would be easy to understand if you imagine a robotic vacuum cleaner. (For some models) It goes back to a specific place automatically to recharge. Like this, I want to make a robot which automatically goes to the place where a specific signal(like infrared ray) is emitting. Following is the scenario that i've imagined.

1.Set the IR emitter in a specific place of a room. It always emits Infrared ray.

2.I connect 4 IR receiver to my 4WD robot car - front, left, right, and back side.

3.They receive IR from the emitter. I earn the distance from the emitter to each receiver with the intensity of IR.

4.With these values, Arduino find out which receiver is closest from the emitter and choose the direction to go.

But I could't know this will be possible. Because IR is a kind of light ray, so I can't get the distance with the difference of arrival time(like Ultrasonic). I searched several kinds of IR sensors, but they were only for sensing the possibility of collision.

So my question is these..

1. Can I get the distance and the direction from IR emitter to my arduino device with an IR receiver?

2. If I can, then how many IR receivers do I need? And if I can't, what can I use to substitute IR emitters and receivers?

3. I guess IR can be interrupted because of sunlight or other light. So I guess I need some daylight filter. Do you think it's essential??

• Having looked at using IR for other projects I believe there is substantial conflict in the information that is returned to the sensor due to natural IR (the Sun). – Dopeybob435 Dec 16 '14 at 18:58

If you use several IR receivers (say, 9 of them) spaced out over a $90^\circ$ arc at regular intervals, you will have constructed a makeshift sensor for detecting the angle of a remote IR emitter. Between that and moving (and/or rotating) known distances with your vehicle, you should be able to triangulate the location of the nearest IR source.