Alternate method of obstacle detection for your bot

Paul Baker

Do you employ a switch on your bot to detect when it hits an obstacle (wall or what not)? Have you ever had your bot get "hung up" on an obstacle becuase it·didn't contact the obstacle inline with your switch (hit it at an angle or the obstacle is too low)? (this can also happen with IR avoidance schemes when hitting a narrow obstacle such as a chair leg or a dark obstacle)

Well I ran across this article which detects the increase in current in your motor caused by a stall (motor is energized but not moving). With minor modification you can adapt it to signal your controller when such a situation occurs, (IC2's out goes to input pin of controller instead of shuting off the H-Bridge)
http://www.edn.com/article/CA323022.html?spacedesc=designideas

Hope some of you find it useful,
Paul

Robert Schwartz

Thats pretty cool. Might have to try and implement that sometime. I generally just use IR for long distance, a bumper, and a tilt switch in case up inclines/declines.