Contest Entry Xr-B3 - My latest robot

[lnxfergy]

Thought I would post some pictures of my latest robot, Xr-B3. He is powered by an AVR ATMEGA324P micro controller on a custom board that I made. He is using an XBEE module to communicate with my PC (and eventually with other robots). Onboard sensory includes: 3 Sharp IR sensors (for wall following and obstacle detection), an SRF-05 sonar sensor and AVRcam. The sonar and camera are mounted in a 2-axis head. He also has quadrature encoders on each wheel, I currently have code implemented for closed loop turns and rolling forward a set distance, but have yet to do continuous speed control.



UPDATE: I've now gotten most of the mapping code working. He can make metric maps of small areas - or topological maps of larger areas. And in theory he can make topological maps from metric maps... but I've pretty near run out of memory to handle that - 2K of RAM only goes so far. I've added a pic below of the Map-Builder GUI (written in Python) which displays his map:





Here is B3 running through the Maze. This video doesn't show any backtracking (I'm still having issues with the transitions):



And, a quick video of B3 using his AVRcam to follow an object:


-Fergs

[Adrenalynn]

It aint easy being green, as Kermit would have it, but it sure looks sexy!

Awesome bots!

Did you do the image processing code on that little processor for video object following?

Welcome to the forum, btw!

[lnxfergy]

Originally Posted by Adrenalynn

Did you do the image processing code on that little processor for video object following?

I did not write the image processing code - it is built into the open-source AVRcam (www.jrobot.net). It's a blob tracker, up to 8 blobs at 30FPS. However, it does run on a little processor - actually an ATMEGA8 (and uses only 4k of the available flash). My mega324 then connects to the mega8 on the AVRcam using the serial port (which is the reason I am using a mega324, it has dual hardware serial ports - 1 for the xbee/pc connection and 1 for the camera)

Although I didn't write the code on the AVRcam currently, I am working on making my own frame manager that would return proper data for road following. Using the AVRcam means I don't have to do hardware and systems design for the interaction with the camera, I can just plug in a different frame manager which gives out different processed data.

-Fergs

[Tyberius]

Very nice man, I love the color scheme.

Now you are making me want to pickup one of those AVRcams too lol

You planning on posting on the other two bots?

[lnxfergy]

Originally Posted by Tyberius

Very nice man, I love the color scheme.

Now you are making me want to pickup one of those AVRcams too lol

You planning on posting on the other two bots?

Yeah, the AVRcam is quite awesome - the only caveat is the documentation (rather, the lack thereof). Still for a $100, its quite good (especially the open-source aspect). I'm still having some crashes with the interaction between the two micros, but once I figure that out I will post the code....

The other two bots - I'll start another thread on the other big one shortly.

The smaller bot in the picture is really just a stripped down version of B3, made to be really cheap. I'm working on that for another upcoming project - all I will say right now is that I intend to have 12-16 of those small ones working in unison on a task.......

-Fergs

[Adrenalynn]

Thanks for the pointer! Pretty cool!

[Sienna]

If you call that inside messy, I want to see what you think is clean! The bots look very nice!

[LinuxGuy]

Originally Posted by Tyberius

Now you are making me want to pickup one of those AVRcams too lol

You might want to check out the CMUCam3 or the Blackfin Camera Board. More processing power for video stuff.

8-Dale

[LinuxGuy]

Originally Posted by lnxfergy

Thought I would post some pictures of my latest robot, Xr-B3. He is powered by an AVR ATMEGA324P micro controller on a custom board that I made. He is using an XBEE module to communicate with my PC (and eventually with other robots). Onboard sensory includes: 2 Sharp IR sensors (for wall following and obstacle detection), an SRF-05 sonar sensor and AVRcam. The sonar and camera are mounted in a 2-axis head. He also has quadrature encoders on each wheel, I currently have code implemented for closed loop turns and rolling forward a set distance, but have yet to do continuous speed control.

Very nicely put together! You have me wondering what I might be able to do with a few AVRs now... I've been tinkering using PICs/dsPICs, and there are some PICs with Ethernet or USB, but I have not actually applied any of these to robotics (yet).

8-Dale

[lnxfergy]

Originally Posted by robotguy

You might want to check out the CMUCam3 or the Blackfin Camera Board. More processing power for video stuff.

8-Dale

They are, however, quite a bit more expensive. Still, I am looking at getting a blackfin some day.

The default AVRcam is actually only using 4k of it's 8K of ROM, and about 700bytes of the 1k of RAM. The newer mega168 is pin-for-pin compatible with the mega8, and doubles the RAM and ROM. Processing time wise, it is pretty busy when tracking at 30FPS, but you could still squeak a little more out of it. Further, 30FPS is really overkill for small robots (my servos can't really update to more than about 3 positions per second and the extra bandwidth eats up processing time and serial port usage).

I'm currently working to port the code to the 168, and reduce the FPS to about 10-15, which will allow more on-board processing to take place.

-Fergs