Subject:
|
Re: Positioning
|
Newsgroups:
|
lugnet.robotics
|
Date:
|
Thu, 27 Jan 2000 22:04:41 GMT
|
Original-From:
|
Pete Hardie <pete.hardie@dvsg.sciatl.com+Spamless+>
|
Viewed:
|
1131 times
|
| |
|
|
David Leeper wrote:
>
> Hi Pete,
>
> I was looking back over you post and realized I didn't answer a couple of your
> questions.
>
> > what are the steps leading up to "...when you get to the X..."?
>
> In the program I wrote there are only a few commands. Go forward. Turn left at
> landmark X. Turn right at landmark X.
>
> > And how does
> > a bot determine that it has not found a landmark and needs to ask more
> > directions.
>
> To be honest, I ignored the problem. Although I knew it could happen in
> theory, in practice it never did, though I admit it was a limited set of
> trials in a static environment. Offhand, I can think of a couple of possible
> solutions. 1) Just stop moving after a given time limit or wheel rotation
> count. 2) Have a set of landmarks that tell you when your lost, as in "If you
> see a McDonalds on your left, you've gone too far." Really, both answers are
> the same. Have a mapping system to tell you when you're not correctly
> following your mapping system.
>
> Again, I think the major flaw in all mapping systems that I've seen is
> the "GO" command. Moving a robot is not acurate and the programmer has to come
> up with ways to deal with the inacuracy, whether its a timer system, a
> rotation system, or landmark system.
The main problem I'm seeing is that the legobot has very short sight, and so it
can
only travel a certain distance before it is nearly sure to miss a landmark, and
then
be lost.
Also, in the Real World (tm), creatures with the limited senses of legobots tend
to
use trail-following methods (ants and scent trails, etc) as the main path
tracking,
and perhaps landmarks to ID branching points. Creatures with long-range senses
use distance measures (bees and the honey-dance)
--
Pete Hardie | Goalie, DVSG Dart Team
Scientific Atlanta |
Digital Video Services Group |
|
|
Message has 1 Reply:
 | | Re: Positioning
|
| Hi Pete, I agree that the short sight is a problem. In my tests, I used wide strips. Three times as wide as the RCX. And they were no more than a foot apart. So missing them would have been difficult. In real life, you could use similar tricks. For (...) (25 years ago, 28-Jan-00, to lugnet.robotics)
|
Message is in Reply To:
| | Re: Positioning
|
| Hi Pete, I was looking back over you post and realized I didn't answer a couple of your questions. (...) In the program I wrote there are only a few commands. Go forward. Turn left at landmark X. Turn right at landmark X. (...) To be honest, I (...) (25 years ago, 27-Jan-00, to lugnet.robotics)
|
28 Messages in This Thread:
 
 
- Entire Thread on One Page:
- Nested:
All | Brief | Compact | Dots
Linear:
All | Brief | Compact
This Message and its Replies on One Page:
- Nested:
All | Brief | Compact | Dots
Linear:
All | Brief | Compact
|
|
|
|
