C-R-M: success using compass inside house for localization ?

[pogo]

Hello everyone.
Has anyone successfully used an electronic compass on a robot inside a house
to help with localization? I was thinking that if a bot knew it was facing a
certain direction then it would only have to search an internal map for
landmarks known to be in that direction.

The kind of compass I am talking about is something like the Hitachi HM55B
Compass Module sold by Parallax.

Any comments ?
jcd

[D Herring]

No luck here. Metal objects cause the needle to wander badly. Check
with a normal compass to see if you have better luck in your environment.

- Daniel

[Gordon McComb]

I've experimented, but nothing definitive. What I found is that you have
to integrate the compass reading with other sensors. It's also a good
idea to keep a historical log of readings (last 30 seconds or so), and
compare those against known changes in heading. This can be accomplished
with basic wheel odometry, for example. That way, if your bot goes by a
table with metal legs you can just toss the readings as anomalistic.

Even for humans, a landmark is the best way to reorient yourself. You're
back to beacons, scanning the patterns in the ceiling to map the room
whereabouts, and what-not.

-- Gordon

[dan michaels]

You might check this out ....

http://www.robotics.com/arobot/compass.html

[pogo]

"D Herring" <dher...@at.tentpost.dot.com> wrote in message
news:duOdnf28Uco8X2vb...@comcast.com...

Yep - that is kinda what I expected. A while back I put a regular camping
type compass on my dashboard and headed "North" no matter which way I
turned. Heh heh heh ... Maybe I should just put a big magnet on every
Northern wall ... :-)

JCD

[pogo]

"Gordon McComb" <NOSPA...@NOrobotoidSPAM.com> wrote in message
news:46F6E3...@NOrobotoidSPAM.com...

Yep - this is and other answers are kinda what I expected. Guess I will have
to label my robots "for use in wigwams only" ...