mBot arduino navigation

The mBot is an Arduino-based rover robot. This video shows how it navigates away from obstacles using the ultrasonic sensors up front. The challenge in programming the obstacle avoidance was to find the a) best distance at which the mBot rover should stop moving and b) by how much it should reverse-drive to change course.

Make (a) too short and it will get trapped in tight spots (there's a point in the video that this happens). Make (a) too long and it will not move at all especially in smaller places. Make (b) too short and it will go nowhere. Make (b) too long and it could back up into other obstacles.

The sensors look like cylindrical eyes. They emit ultrasonic waves that bounce off obstacles. Because of this, the sensors could actually measure distance.

I verified the distance measurements using a tape measure. Not that a tape measure is very accurate, but the distance the ultrasonic sensors reported were actually quite good. I lost my notes on this one, but I will soon reactivate this robot and post the measurement experiments here.