To LUGNET HomepageTo LUGNET News HomepageTo LUGNET Guide Homepage
 Help on Searching
 
Post new message to lugnet.roboticsOpen lugnet.robotics in your NNTP NewsreaderTo LUGNET News Traffic PageSign In (Members)
 Robotics / 6840
6839  |  6841
Subject: 
Re: New Lego challenge !
Newsgroups: 
lugnet.robotics
Date: 
Mon, 13 Sep 1999 20:20:51 GMT
Viewed: 
536 times
  
In lugnet.robotics, Wes Matchett writes:

Laurentino Martins wrote:

At 03:35 13-09-1999 Monday , Mike Poindexter wrote:
Got it figured out.  Using the principles of right handed recursion, you • can
have the robot follow the right wall and it will eventually get to the • light
and also get out of the maze again.

Incidentally, right handed recursion will get you out of any labyrinth
provided that you are not starting inside it already.  If you are already • in
it, it will likely work there as well.  This would then allow the robot to
work in almost any maze you create.

Yes, unfortunately the current firmware implementation from LEGO doesn't
have a call stack, so you can not build recursive routines. :-(

On the other hand I can imagine labyrinths where that bot would never be • able to do anything out of them.

A call stack is not an absolute requirement to do recursive processing, it
just
makes it easier.  I have written recursive processes with only an array.

-Wes

Unfortunately, the default RCX firmware doesn't support arrays, either.

Also, the assertion that you can simply follow a wall in order to traverse an
entire labyrinth actually depends on the maze conforming to a certain
topology.  I'm sure there's probably some technical/mathematical term for it,
but basically, you are assuming that there are no open loops through the
maze.  It is actually very easy to design a maze which will foil a simple wall-
following algorithm.

I don't see any mention of the maze topology in the contest rules.  Perhaps
this would be worthy of clarification?



Message has 1 Reply:
  RE: New Lego challenge !
 
This is a REALLY good idea. Here's something I had kicking around in my head... 1. Making a maze that we can all use is kinda hard. 2. Making a bot small enough to fit a standard buildable maze is really hard. I propose we invert the problem a (...) (25 years ago, 13-Sep-99, to lugnet.robotics)

Message is in Reply To:
  Re: New Lego challenge !
 
(...) A call stack is not an absolute requirement to do recursive processing, it just makes it easier. I have written recursive processes with only an array. -Wes (25 years ago, 13-Sep-99, to lugnet.robotics)

22 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
    

Custom Search

©2005 LUGNET. All rights reserved. - hosted by steinbruch.info GbR