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Subject: 
Re: Line Followers
Newsgroups: 
lugnet.robotics
Date: 
Tue, 16 Nov 1999 19:23:41 GMT
Viewed: 
1784 times
  
On Tue, 16 Nov 1999, Paul Speed wrote:
> > My two cents:
> > 1) maybe a half or 3/4 circle would be all that is needed? No
> > twisting problems then.
> 
>         True, but I sort of like the idea behind having a sort of
> blip at four compass points.  It makes maze navigation a simple
> problem and then I can focus on maze traversal.

Hmm. If you only blip at the compass points, what happens if you "cross"
a fork while between one of the four points?

> > 2) When you rotate the bot, any idea on how you will realign the
> > sensor to the bot's new direction?
> 
>         That was the idea behind the synchro platform.  The bot will
> always be "facing" the same way which is one of the things that
> necessitates a full circle sampling.  Initially I will focus on
> movement restricted to 90 degrees.  Eventually it would be nice to
> develop a more general solution that can handle more than four
> directions.

Ahh. I missed the synchro part. Crazy. :)
-Luis

>         -Paul (pspeed@progeeks.com, http://www.progeeks.com/)
> 
> > 
> > Just some thoughts-
> > Luis
> > 
> > >       I will leave solutions to the problem of keeping the light
> > > sensor cable from getting twisted as an exercize for the reader.
> > > (heh)  At least until I've built a working example.  Speculation is
> > > always so much easier than proving that it will work. :)
> > > 
> > >       -Paul (pspeed@progeeks.com, http://www.progeeks.com/)
> > > 
> > > Luis Villa wrote:
> > > > 
> > > > With just one light sensor, the problem is that you have to guess
> > > > which direction you just fell off the line. i.e., your sensor
> > > > suddently goes from dark to light. Is the dark to your left? Your
> > > > right? There's no real way of telling, is there?
> > > > 
> > > > If you guess well, you can follow the line well. If you don't guess
> > > > well, you are in trouble. Frankly, I have no strategies for
> > > > guessing well. However, "go x left, 2x right, 3x left, 4x right" is
> > > > not unreasonable, and I believe some variation on that (perhaps x
> > > > left, 2x right, 4x left, 8x right, but I'm not sure) is
> > > > mathematically provable to be the best solution for this type of
> > > > problem. Note: these are not actually go left, but spin left, spint
> > > > right, etc. with the assumption that you have stopped when you "lost"
> > > > the line.
> > > > 
> > > > With two light sensors, this suddenly becomes much easier, and with
> > > > three, you can build a great light sensor. However, forks still
> > > > aren't dealt with well- you need depth as well as breadth to be able
> > > > to analyze those robustly and on the fly (in my opinion). Anyone
> > > > have any thoughts on that one?
> > > > -Luis
> > > > 
> > > > On Tue, 16 Nov 1999, David Morgan wrote:
> > > > 
> > > > > Date: Tue, 16 Nov 1999 00:08:59 GMT
> > > > > From: David Morgan <lego-robotics@crynwr.com>
> > > > > To: lugnet.robotics@lugnet.com
> > > > > Subject: Line Followers
> > > > > 
> > > > > Hi,
> > > > > 
> > > > > Could someone please give me a little bit of advice on building a line
> > > > > follower with the standard lego light sensor? I will be doing the
> > > > > programming  for it with LegOS.
> > > > > 
> > > > > Can you achieve decent performance with just one light sensor?
> > > > > 
> > > > > Thanks!!
> > > > >      Dave Morgan
> > > > > 
> > > > > 
> > > > 
> > > > #######################################################################
> > > > 
> > > >      Profanity is the one language that all programmers understand.
> > > >                           -Anonymous
> > > > 
> > > > #######################################################################
> > > 
> > > 
> > 
> > #######################################################################
> > 
> >      Profanity is the one language that all programmers understand.
> >                           -Anonymous
> > 
> > #######################################################################
> 
> 

#######################################################################

     Profanity is the one language that all programmers understand.
                  -Anonymous

#######################################################################



Message is in Reply To:
  Re: Line Followers
 
(...) re: Mechanical mess - agreed. :) Hopefully, and elegant solution will present itself there too. (...) True, but I sort of like the idea behind having a sort of blip at four compass points. It makes maze navigation a simple problem and then I (...) (27 years ago, 16-Nov-99, to lugnet.robotics)

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