Boe-bot InfraRed Roaming

Computeruser

I put together the IR LED's and detectors on the breadboard and wired it according to the manual. I tested in steps and all works.

I entered the FastIRroaming program and it works.

I have tried various orientations of the IR LED's and have been most successful with one pointing slightly up (Right IR) and one pointing more up (Left IR). This works too. It all works.

BUT, it cannot "see" everything. It does not see: small things (slippers), sofa legs (too small, but the boe-bot won't go underneath), the glass TV doors (makes sense) and so on. So it sees large things and turns and it sees nothing and keeps going forward in a straight line.

Question: Can I make it see more things? I can buy a parts kit here. Perhaps I could add a third detector.

Thanks, ... C

Mike Green

Think of the IR LEDs as flashlights and the IR detectors have an angle of view of maybe 20-25 degrees off axis (for a 40-50 degree cone). See the datasheet (from the IR detector product webpage). That's pretty coarse and won't likely detect small things.

You could narrow the angle of view with a black plastic shield like what's used with the IR LEDs. That would also reduce the sensitivity, but there may be enough. The problem still is how to point the IR detector in the right direction and illuminate the scene with the IR LED well enough so the IR detector can see small objects (get enough reflection back to trigger the detector). That's not simple, particularly to do it fast enough to be practical.

Duane Degn

The items to be detected need to reflect IR in order for the detectors to see the reflected light. Since our eyes don't see IR, it won't be obvious which objects reflect IR.

Ultrasound also has limitations. Some objects absorb ultrasound and other reflect the ultrasound away from the detector. In both these cases, the obstacle will go undetected when using only ultrasound.

I've noticed that IR sensors and ultrasound sensors compliments each other well. Obstacles unseen by one sensor are often seen by the other.

I was very pleased with how well my Scribbler 2 was able to detect obstacles after I added an ultrasound sensor. There were still some obstacles which remained undetected by both the IR and ultrasound sensors. In these cases I had to rely on the Scribbler 2's tail wheel encoder to sense when he S2 was being stopped by some unseen obstacle. Some sort of touch sensor could be used in place of a tail wheel encoder to sense these "invisible" obstacles.

erco

This is Duane's first and only obstacle sensor post where he didn't mention his "invisible" couch, IIRC!

So clearly you are an impostor!

What have you done with my friend, the REAL Duane Degn?