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Subject: 
Re: searching walls
Newsgroups: 
lugnet.robotics
Date: 
Tue, 27 May 2003 12:02:42 GMT
Original-From: 
Steve Baker <sjbaker1@airmail.STOPSPAMnet>
Viewed: 
818 times
  
The start position/orientation don't have any restriction.
I'm working with 2 rotation  sensors(each per left/right motor-wheel) and 1
ultrasonic sensor(technicstuff) that can rotate(but without rotation sensor
because are 1 RCX), with leJOS.

If you use an adder/subtractor mechanism for driving the robot then
you can have one rotation sensor measuring how much you are turning
and the other measuring how far forwards you are driving.

Then, you can have the ultrasonic sensor driven from the same output
of the adder subtractor mechanism as the 'forward/backward' rotation
sensor.  As the robot drives along, the sensor will be rotatated and
your software can continuously measure the distance out in any direction.

Alternatively, you could remove the forward/backward rotation sensor
and use the ultrasonic detector (pointing forwards) to figure out how
fast you are moving by measuring how rapidly the distance to the next
wall decreases.  That frees up an RCX input that you can use to measure
the direction the ultrasonics are pointing.

However, through all of this, beware.  The lego rotation sensor has
a tendancy to lose or gain counts when it's rotated very slowly.

This can result in a cumulative error that would mean that your
idea of which way you are steering (or pointing the sensor) would
gradually get less and less accurate.

---------------------------- Steve Baker -------------------------
HomeEmail: <sjbaker1@airmail.net>    WorkEmail: <sjbaker@link.com>
HomePage : http://www.sjbaker.org
Projects : http://plib.sf.net    http://tuxaqfh.sf.net
            http://tuxkart.sf.net http://prettypoly.sf.net
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Message has 1 Reply:
  THOUGHTS on mapping with Lego Robot ( added to searching walls)
 
Hello, What I want to do is take a five foot by five foot square, put random items in the square, MAP THE SQUARE AND OBSTACLES and run our dog robot around the course and never have it stop. I do not want to do obstacle avoidance (that is much (...) (21 years ago, 27-May-03, to lugnet.robotics)

Message is in Reply To:
  Re: searching walls
 
For the drive, can you apply an adder-subtracter mechanism using one rotation sensor? If so, other rotation sensor could be used on rotating ultrasonic. (...) (21 years ago, 27-May-03, to lugnet.robotics)

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