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Hellfire
01-20-2009, 10:47 PM
I dont know if there's a thread on this yet or not, so i posted in garage sale, and someone suggested a wheeled bot, that follows black lines, that's new... looked great, and spawned an idea for me..


So just curious i think this is possible and easy..... any feedback would be greatly appreciated

So i'm going to pick up that nifty little black line bot, but i was wondering if i could mod it...

Since it's circular, i was thinking putting in Sonar/Range sensors putting them at 12/3/6/9 o'clock..
Have it sonar to determine range/distance to walls, and upload to a cad program? cad would be a bit beefy tho, so i'd have to find something smaller...

Then rotate 45 degrees and do the same thing to just make sure didnt miss any cadi-corners

and create a map of area



Then futuristic plans would be to make spots on the map it created and see if it can find the location? wonder if that would work.... that's how i can start my fetch bot... get it a layout of the area, and start labeling things for it to get/fetch....


Thoughts?

Adrenalynn
01-21-2009, 01:29 AM
>> putting them at 12/3/6/9 o'clock

Alas, not enough pins that I can see spare on the processor. Maybe you can expose the I2C pin and daisy chain them, that might be a possibility.

lnxfergy
01-21-2009, 09:07 AM
>> putting them at 12/3/6/9 o'clock

Alas, not enough pins that I can see spare on the processor. Maybe you can expose the I2C pin and daisy chain them, that might be a possibility.

You could disconnect something (hmm.... LCD?) to get more pins

-Fergs

lnxfergy
01-21-2009, 09:14 AM
Since it's circular, i was thinking putting in Sonar/Range sensors putting them at 12/3/6/9 o'clock.. Have it sonar to determine range/distance to walls, and upload to a cad program? cad would be a bit beefy tho, so i'd have to find something smaller...

Then rotate 45 degrees and do the same thing to just make sure didnt miss any cadi-corners

and create a map of area

Then futuristic plans would be to make spots on the map it created and see if it can find the location? wonder if that would work.... that's how i can start my fetch bot... get it a layout of the area, and start labeling things for it to get/fetch...

Building a map isn't terribly difficult - building an accurate one is! (Look at: OCCUPANCY GRIDS). Not sure about loading up to a CAD program, how are you gonna get the data off the bot and up to a computer? (possiblities: XBEE?)

As for rotating 45 degrees... yeah the hard part of map building is knowing where the bot is: the 3Pi has no ENCODERS, so it can't keep track of movement - even turning 45 degrees is gonna be hard (sometimes it will turn 35, others 55, its probably never turning exactly 45). Also, the longer the bot runs, the more inaccurate the map will get...

Lastly, maps (specifically occupancy grids) take large amounts of memory --- the overall area your bot will be able to map is gonna be pretty small (or your map is going to be very rough - look at occupancy grids and grid resolution and you will understand exactly what I mean).

But, its a place to start. I have some sample code for AVRs (which the 3PI uses) on my SVN server http://svn.blunderingbotics.com The directory XRA4 is a mega168 based robot, XRB3 is another of mine that uses a mega324 (type of AVR) and does occupancy grid mapping...

-Fergs

Hellfire
01-21-2009, 09:42 AM
Now mind you this is just a work in progress, figure if i'm going to "think about" or start small, with something pre-kit...

I'm not all for line following lines which the 3pi is built for, however i'm a cubed employee.... huge floor space, many tiny cubes...

Figure it can roll already, it can already store "learned" paths

The end result even if small to start 1 isle of my cubes which is about 20 cubes. Hoping to end up with a "map" of the 20 cubes.

Then i'd like to have a designated start location for rover, select a point in the map... hopefully have it use the "Learned" path to go there and back.

Trying to start small, go from here to there and back and make sure it has avoidance inbetween. Altho i guess not so small considering i want it to map as it goes...


I figured the 3pi would be pretty easy it states it has room for extra sensors, figured i'd just remove the line senors.

Hellfire
01-21-2009, 10:01 AM
Ok how's about this to make it even easier...
So we know that the little guy can maze solve....

The circles he finds... wonder if he can store multiple "end" locations... A,B,C,D

Then i'd only have to be able to input which location i want it to go to....


So i tape up my cubies.... to start, store a few locations, have him go to the requested location?


Think this may be possible with the little guy?