localisation

N

New˛

Guest
Hello,
I have three small Automated Guided Vehicle wich navigate in a 700*700
square feet area. Using ŕ PC, i want to know at each moment where every one
of these robots is. What are the different method i can use wich give
precise results.
Thanks
 
New˛ wrote:

Hello,
I have three small Automated Guided Vehicle wich navigate in a 700*700
square feet area. Using ŕ PC, i want to know at each moment where every
one of these robots is. What are the different method i can use wich give
precise results.
Thanks
Click to expand...
Keep track of its motion, obviously, but maybe three transponders and
a little triangulation?

Good Luck!
Rich
 
Subject: localisation
From: "New˛" qos1@free.fr
Date: 9/4/2004 4:00 PM Central Daylight Time
Message-id: <413a2d02$0$18621$626a14ce@news.free.fr

Hello,
I have three small Automated Guided Vehicle wich navigate in a 700*700
square feet area. Using ŕ PC, i want to know at each moment where every one
of these robots is. What are the different method i can use wich give
precise results.
Thanks
Click to expand...
I would guess radio beacons would give you all kinds of problems in near field.
If it's an open area with clear sight lines, you might want to try three LED
beacons in the corners (modulating at discrete and easily filterable
frequencies), and put a rotating sensor with a lens in front of it on each
vehicle, along with the intelligence to do its own triangulation of the
identifiable light sources or at least report angular position of the three
beacons. The vehicles could then transmit each in turn to your PC, by radio
link if you prefer.

Half-stepping a good stepper motor for the sensor should get you within better
than a degree for the angle on each of the three beacons, which will give you
an accuracy of within a couple of feet in the x and y axis from any position.
Also, by measuring signal stength at adjacent steps, you might be able to
improve the accuracy just a bit.

This is the type of problem that is very amenable to large infusions of cash to
achieve better results. But if you've got some experience in electronics as
well as robotics, it is doable.

Good luck
Chris
 
"CFoley1064" <cfoley1064@aol.com> wrote in message
news:20040904192321.06263.00000168@mb-m02.aol.com...
Subject: localisation
From: "New˛" qos1@free.fr
Date: 9/4/2004 4:00 PM Central Daylight Time
Message-id: <413a2d02$0$18621$626a14ce@news.free.fr

Hello,
I have three small Automated Guided Vehicle wich navigate in a 700*700
square feet area. Using ŕ PC, i want to know at each moment where every
one
of these robots is. What are the different method i can use wich give
precise results.
Thanks

I would guess radio beacons would give you all kinds of problems in near
field.
If it's an open area with clear sight lines, you might want to try three
LED
beacons in the corners (modulating at discrete and easily filterable
frequencies), and put a rotating sensor with a lens in front of it on each
vehicle, along with the intelligence to do its own triangulation of the
identifiable light sources or at least report angular position of the
three
beacons. The vehicles could then transmit each in turn to your PC, by
radio
link if you prefer.

Half-stepping a good stepper motor for the sensor should get you within
better
than a degree for the angle on each of the three beacons, which will give
you
an accuracy of within a couple of feet in the x and y axis from any
position.
Also, by measuring signal stength at adjacent steps, you might be able to
improve the accuracy just a bit.

This is the type of problem that is very amenable to large infusions of
cash to
achieve better results. But if you've got some experience in electronics
as
well as robotics, it is doable.

Good luck
Chris
Click to expand...
In that size area a RFID tag on each plus three transevers might work .
It depends on if the area is empty or full of walls also.

Charles.
 
"New˛" <qos1@free.fr> wrote in message
news:413a2d02$0$18621$626a14ce@news.free.fr...
Hello,
I have three small Automated Guided Vehicle wich navigate in a
700*700 square feet area. Using ŕ PC, i want to know at each moment
where every one of these robots is. What are the different method i
can use wich give precise results.
Thanks
Click to expand...
Maybe GPS will work:

http://www.cs.kent.ac.uk/projects/mobicomp/Fieldwork/Notes/gps_if.html

You might use a wireless 802.11 link between the handheld and your
desktop. It won't give you totally precise values, but it should be
relatively accurate to a meter or so. If you get a 4th GPS unit, you
might be able to use differential GPS to locate the roving systems
exactly.

Regards,
Bob Monsen
 
In that size area a RFID tag on each plus three transevers might work .
It depends on if the area is empty or full of walls also.
Click to expand...
Yes, the area contain many walls.
 
I'd like to throw my three pennyworth into the pot.

Would it be possible to lay a matrix of wires on the floor area and give
each robot a unique coded frequency fed to a coil in the base.

The X and Y wires could be interrogated for a pulse and the frequency would
denote which robot was over a junction.

It's just an idea, someone may be able to enlarge on.

Kind regards, Gordon.

----------------------------------------------------------------------------
-------------------------
"New˛" <qos1@free.fr> wrote in message
news:413a2d02$0$18621$626a14ce@news.free.fr...
Hello,
I have three small Automated Guided Vehicle wich navigate in a 700*700
square feet area. Using ŕ PC, i want to know at each moment where every
one
of these robots is. What are the different method i can use wich give
precise results.
Thanks
Click to expand...
 
"New˛" <qos1@free.fr> wrote in message
news:413b1c90$0$21354$626a14ce@news.free.fr...
In that size area a RFID tag on each plus three transevers might work .
It depends on if the area is empty or full of walls also.

Yes, the area contain many walls.


With walls light based systems aren't really usable. So use some form of RF.
Click to expand...
RIFD tags are smallish and already exist. Using a tranmitter on each unit
requires only that they have different frequencies and that the signal
proccessing used be differential . By comparing each receivers signal
strength against the other two you can form a location even if the
transmitter is weaker with time.More receivers will also give improved
location.

Charles
 
On Sat, 04 Sep 2004 23:00:54 +0200, New˛ wrote:

Hello,
I have three small Automated Guided Vehicle wich navigate in a 700*700
square feet area. Using ŕ PC, i want to know at each moment where every one
of these robots is. What are the different method i can use wich give
precise results.
Thanks
Click to expand...
Tile the floor area in a checkered grid like this:

- alternating black and white squares, but each black square has a
thin white stripe down the centre, thinner than the floor area of the
robot, and each white square has a black stripe. The stripes are all
facing north-south.
- Add in a series of barcoded north/south and east/west stripes every
so-many grid squares, which give an absolute reference, in case of
counting errors.
- have an array of reflectivity sensors on the bottom of the robot, which
looks at the floor and works out where it is in the grid pattern by
counting transitions from one grid square to the next.

you should be able to work out some algorithm based on this that will work
out where the robot currently is.

--
http://www.niftybits.ukfsn.org/

remove 'n-u-l-l' to email me. html mail or attachments will go in the spam
bin unless notified with
HTML: 
 or [attachment] in the subject line.
 
Either accurate Radio Direction finding with triangulation or have each have
a map of known obsticales and Ultrasonic detectors.

See the links here

http://dingoaus.proboards34.com/index.cgi?board=genelectronics&action=displa
y&num=1093575327


"New˛" <qos1@free.fr> wrote in message
news:413a2d02$0$18621$626a14ce@news.free.fr...
Hello,
I have three small Automated Guided Vehicle wich navigate in a 700*700
square feet area. Using ŕ PC, i want to know at each moment where every
one
of these robots is. What are the different method i can use wich give
precise results.
Thanks
Click to expand...
 
andy <news4@earthsong.free-online.co.uk> wrote in message news:<pan.2004.09.05.19.38.27.561337@earthsong.free-online.co.uk>...
On Sat, 04 Sep 2004 23:00:54 +0200, New˛ wrote:

Hello,
I have three small Automated Guided Vehicle wich navigate in a 700*700
square feet area.
SNIP
Tile the floor area in a checkered grid like this:
SNIP
Click to expand...
Or tile the ceiling area. Just like in horry movies, people forget to look up!

http://techref.massmind.org/techref/new/letter/news0308.htm has a few ideas on this.
 
cfoley1064@aol.com (CFoley1064) wrote in message news:<20040904192321.06263.00000168@mb-m02.aol.com>...
Subject: localisation
From: "New˛" qos1@free.fr
Date: 9/4/2004 4:00 PM Central Daylight Time
Message-id: <413a2d02$0$18621$626a14ce@news.free.fr

Hello,
I have three small Automated Guided Vehicle wich navigate in a 700*700
square feet area. Using ŕ PC, i want to know at each moment where every one
of these robots is. What are the different method i can use wich give
precise results.
Thanks

SNIP
Half-stepping a good stepper motor for the sensor should get you within
better than a degree for the angle on each of the three beacons, which will
give you an accuracy of within a couple of feet in the x and y axis from any > position.
Click to expand...
<SNIP>

And you can certainly do more than just half step, for example, the
Linistepper controller supports up to 18th over stepping or 3600 steps
per revolution from a standard 200 motor.

http://www.piclist.com/techref/io/stepper/linistep/index.htm
 
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