How to find distance and direction of IR signal?

Question

I am wondering where I should start in trying to get my Raspberry Pi to detect the distance of an IR signal and the direction of it. Has someone already done something similar? The end goal is to get a RPi robot to follow the signal; move towards it if the signal is too far away.

Answer 1

Another approach is based on stereoscopy - a technique used for recording and representing stereoscopic images. Which means that we need a pair of cameras that take pictures at slightly different positions. Using image processing corresponding features (e.g. edges of objects) are detected in both images - allowing to calculate the distance.

If using with an IR beacon image recognition could be simpler - thus reducing computational time, but make sure that the camera can pick up on IR. (Major drawback there's only one camera interface on the Pi.)

Some reading to get started:

• Distance measuring based on stereoscopic pictures
• Distance to the object using stereo camera using openCV

Answer 2

Detecting the location and distance of an IR signal is tricky. To start, you'll need at least two IR receivers. Each IR receiver can detect the strength of the signal, and using the combined information, the CPU can calculate a rough location.

Cornel has a decent write up (source of the image above).