projects help

C.J. Powers

I am using a Boebot with the CMU camera for a school project, we are trying to decide what we want it to do, the only requirements are that is isn't a simple one task and its done type project, my group had an idea that we could make it stay on a table top, and roam around until the CMU spotted a colored cube then pick it up with the grabber arm attachment. is this possible? I am brand new to the boebot, so its capability is beyond my knowledge. Thanks

Ugha

This should be possible.

You can use IR transmitter/receiver pairs to detect the edge of the tabletop... the rest is up to the CMU camera, gripper and your programming skills.

Jonathan

Well, part of it depends on exactly what level you want to go to. Making a robot that would do it every time, very quickly, would be real hard. Making one that does it sometimes would be pretty easy. And then you have everything inbetween.

As mentioned above, you can use line sensors to detect a table edge, by putting white or black tape around it. However, I wouldn't do a tabletop, get a piece of plywood and put it on the floor. That way it won't plummet to it's death. [noparse]:)[/noparse] The Sumobot sample code has good details on doing this, and it's available for a free download.

In addition to the CMU cam, I'd have an ultrasonic sensor like the ping and some IR sensors like Sharp makes. Finding a color blob with the CMU cam is one thing, but you have to get the grippers lined up. You will also likely want a contact sensor to be able to tell when you have the object in the gripper before you try to pick it up.

Overall, I'd say it's an ambitious project to start with, but ambition is good!

Jonathan

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
www.madlabs.info - Home of the Hydrogen Fuel Cell Robot

Ugha

If you use a normal IR pair you don't have to use black tape... one in the front pointing down off the breadboard, and one in the rear pointing back to keep it from backing off the table.

This isn't as good as the QTI-like line sensors that Jonathan is recommending because you can't get as close to the edge... but the parts are supplied by the boebot kit so free = good.

I'd tend to agree with jonathan... lining up the gripper may be tough without additional feedback. Maybe you could put some bright yellow or red dots on the edges of the gripper to help
the CMU cam detect them? I'm afraid I don't actually own the CMU cam so I don't know what it is able to do.

I wouldn't recommend using a Ping for this though because if you place it directly on the breadboard it may end up being too close to get exact readings (I have problems with my ping
judging things too close... although that could just be my poor coding skills).