Quote:
Originally Posted by gnormhurst
We got the Vex sonar working last night using Mike's driver. I'm really impressed by the whole thing -- it can see a 3' x 4' board at about 15 feet!
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Beware of off-axis error! Depending on what sensor you're using (Parallax PING))) is pretty much your best bet) the further a wall is off axis the worse your measurements will be.
For example, if you were, say, following along a wall and servoing off of the distance from the wall (no idea why you'd want to do that
) you're robot will swerve further and further until it crashes, because, each time the robot veers left or right it alters the distance the ping sensor percieves, even though the distance has barely changed. This escalates until, like I said, you crash.
Instead (and we've used this in the past) use encoders to drive your robot straigh, and use ultrasonics for obstacle detection/avoidance.
Getting a reliable distance to anything at any angle is our current goal at 1024.
-q