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Author Topic: robot with knowledge of location  (Read 1027 times)
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the land of sun+snow
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What I would like to do is create small independant vehicules that interact, modelling forms of social behaviour.

I envisage a vehicule to be able to explore and 'map' its surroundings, a room primarily, together with any permanent obstacles, furniture for example.

Cool, not only have you chosen a first project that will require a lot of work, but now you've
double-downed and added another fair share to it. smiley-cool In academics, people have spent their
entire careers working on one project or the other, with the help of many grad students.

As noted already, there are tons and tons of research papers on these topics. You might check
Maja Mataric's website at USC for swarm robots.

Joe Jones has a couple of good books on "Robot Programming". His 2004 book by that name makes a
big point about the unreliability of most available sensors. For my part, I've been taking more sensor
scans, and finding the sonars are extremely susceptible to ground clutter, due to their wide beams,
when used on a small robot. Finding out what works well in practical situations is a nontrivial task.

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I should think an occupancy grid with 12" squares would be adequate.

I got my first sensor scan this evening, you may find it of interest. I have a Maxsonar EZ0, EZ4, and
Sharp GP2D12 mounted on a pan'n'tilt servo pod. Made a 180-deg panning sweep broken into 24 positions.
I wrote a simple graphing program that displays during the sweep. Two different scans are shown, and
they are very consistent.

Except for the #2 GP2D12 reading, which is flukey for some reason [probably a calc overflow], the
GP2 readings are very close to the actual measurements. The wide beams of the sonars really
wash things out. Even the EZ4, which has about 20deg beam, isn't all that great for definition.

Readings #6 - #9 represent a 14" space, which is about 38" deep, between 2 objects which are approx
15" away from the robot. The GP2D12 easily picks it up, the Maxsonars wash it out. I can see that room
mapping with sonars is not super accurate.

Code:
Servo Tank Program ... test2 ... IDE 1.0

L=wide-beam  R=narrow-beam  G=GP2D12
-----------  -------------  --------
(distances in inches)
dist=18 22 25                  L   R  G
dist=16 17 392               LR                                  G
dist=16 16 23                LR      G
dist=16 17 20                LR  G
dist=15 16 20               LR   G
dist=19 16 28                R  L        G
dist=18 16 36                R L           G
dist=12 12 37            LR                        G
dist=12 12 38         LR                         G
dist=10 12 16          L R   G
dist=11 12 14           LR G
dist=11 12 14           LR G
dist=12 12 10          G LR                               
dist=15 15  7       G       LR                               
dist=15 10 20          R    L    G
dist=15 11 24           R L        G
dist=15 10 25          R    L         G
dist=15 10 24          R    L       G     
dist=15 10 23          R    L       G
dist=21 21 23                     LR G
dist=21 21 24                     LR  G
dist=19 22 24                   L  R G
dist=21 22 25                     LR  G
dist=21 25 26                     L   RG


dist=21 21 24                     LR  G
dist=16 17 321                LR                                  G
dist=16 19 23                 L  R   G
dist=16 17 21                LR   G
dist=15 16 20               LR   G
dist=18 15 30               R  L           G
dist=15 19 38               L   R               G
dist=12 12 36            LR                       G
dist=12 12 38            LR                         G
dist=11 12 15           LR  G
dist=11 12 13           LRG
dist=11 12 14           LR G
dist=12 12 10          G LR
dist=15 15  7       G       LR
dist=15 11 20           R   L    G
dist=15 10 24           R  L        G
dist=15 11 25           R   L         G
dist=15 11 24           R   L        G
dist=15 10 24          R    L        G
dist=19 22 24                   L  R G
dist=21 21 24                     LR  G
dist=21 22 24                     LR G
dist=21 25 26                     L   R

Dan, please could I see your code for the occupancy grid? Thank you
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