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Subject: 
Re: Autonomous Robot
Newsgroups: 
lugnet.robotics
Date: 
Wed, 2 Aug 2000 20:44:51 GMT
Original-From: 
Andy Gombos <gombos_2000@*spamless*yahoo.com>
Viewed: 
1040 times
  
For mapping, you can use an ultrasonic sensor, like the one designed by John
Barnes. This can find open areas up to 2 meters/yards away. Storing only object
locations is best, IMO, because it uses the least space (there were posts on
this before..). Then you can just see if your current path intersects any of the
known obstacles.

Andy

P.S. I would love to help you. I have been trying to do something like this for
as long as Mindstorms has been out. You brought some new ideas to my project.

Mauro Vianna wrote:

Jason,

Of course a second brain will help!

Everything is in my mind yet and lots of issues are not solved. I hope this
post generates interesting discussions on how to solve them. As I said I
will test these approachs in a slow pace, most because of my lack of time
than my will. I want to post all interesting features I achieve (maybe even
a simple site later?).

Although the project may seen a complex one, I want to test a lot of smaller
tasks at a time, so that I can join them later as a bigger problem. For
example, I have tested the following features until now:

1) A sonar-like feature using the RCX IR emiiter and a light sensor to
detect IR reflections. It was described in this list earlier (not by me). It
worked fine but wasted batteries fast. Some people gave me a few tips to
save them, but I did not test yet.

2) An algoritm to use light detection as a compass. The basic idea is that
my window is the brighter light in the room (it only works during the day)
so if you detect the brighter light source you can find a direction without
a compass. Not my idea really. See the Ants project at MIT site. The author
copied it from real ants too! Sorry, I lost the URL. :(
It's not precise and depends a lot of the environment but it worked well in
my apartment since all windows are on the same direction.

Unfortunatelly I don't know LegOS and in fact I don't want to learn it right
now. I know the language is powerful is good but don't have the time now. I
mentioned both LegOS and QC since those don't have the same memory
limitations of the original firmware.

NQC is bound to the firmware variable limit, so map representation is not
possible unless it is hard coded. One workaround I thought about was to use
a simple NQC program that explores the environment and send information to
the datalog. Then it returns to a location where the IR tower can reach it.
A more complex Visual Basic program could process the datalog and create a
NQC code to represent the map from the datalog info and download the new
program with the hard-coded map. The idea itself is simple. The main problem
would be the lack of precision of the explorer info. RCX doesn't have GPS,
compass, etc. so obstacle location would not be real precise.
Of course, we can simplify the problem. In fact I don't need to know where
the obstacle is, but where it isn't. Once a path is found (e.g. straight
movement for 2 meters without obstacle), we can store only this information.
A simpler map algoritm could be used. David Leper used a similar one in his
site: http://www.geocities.com/Colosseum/Dome/5088/Hand.htm (This is not the
root!)

Mauro

"Jason" <jasonrowoldt@yahoo.com> wrote in message
news:FyMqs8.9Bx@lugnet.com...
In lugnet.robotics, Mauro Vianna writes:
I had an idea to a project that I want to start in a very slow pace. In
fact, it is based in lots of ideas already presented here in this list so • I
am not sure if someone already tried it before. Any help is welcome.
The main goal is to build a Lego robot able to navigate inside my home
without assistance. Although it is simple, it involves a lot of issues, • some
of then already discussed here. The main approach follows:


<snip a really interesting concept>

Wow, I would love to see documentation of the process you go through here.
Alone you might get discouraged with so complex a task.  I got the • Mindstorms
1.0 a few months ago but have yet to really fool with it.

This may be what jumpstarts my activity.

Let me catch up with you, especially with LegOS, and I'll be a second • brain for
this project if you'd like.

Jason



Message has 1 Reply:
  Re: Autonomous Robot
 
"Andy Gombos" <lego-robotics@crynwr.com> wrote in message news:39888843.D78EFA...hoo.com... (...) John (...) I saw a sensor like that in Michael Gasperi site ((URL) Maybe it's the same one. I am trying to use Lego pieces only. Don't understand me (...) (24 years ago, 4-Aug-00, to lugnet.robotics)

Message is in Reply To:
  Re: Autonomous Robot
 
Jason, Of course a second brain will help! Everything is in my mind yet and lots of issues are not solved. I hope this post generates interesting discussions on how to solve them. As I said I will test these approachs in a slow pace, most because of (...) (24 years ago, 2-Aug-00, to lugnet.robotics)

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