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Unread 21-01-2006, 22:33
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Re: Scoring Corner Goals During Autonomous

Let's handle these one at a time

Quote:
Originally Posted by CronosPrime1
Wow thanks for the amazingly quick replies. It's nice to know that for once in your life you're in a forum that's actually helpful. I am a newbie to programming using sensors. Could someone explain to me what dead reckoning is and what would be involved in making such a program?
Dead reckoning is the simplest form of autonomous movement, in that it doesn't require feedback, you just do things based on timing loops. All you do is tell your bot to do things like "turn left for 0.1 seconds and then drive straight forward for 4 seconds, and then activate your ball dumper". It's very simple to do (I can give you some sample code, as our team's bot usually has some sort of dead reckoning code written in case we have problems with the feedback sensors). The obvious problem is that many things can go wrong (wheel slip and other robots getting in the way being the obvious ones), and precise alignment isn't easy.

Quote:
And about the CMU cam - what exactly does it do? Does it return a matrix of pixels or what?
There are some very complete documents on www.kevin.org on what the CMUcam2 does, but basically it checks to see if it's looking at the target, and if it is, it returns the size of the target and it's centroid.

Quote:
Yes, I am planning to position the robot to drive straight to a corner goal in the beginning of the match. It has also been suggested to me that I might know that a corner goal is there by detecting the robot go up a ramp - the corner goal is up a light ramp. Could someone please give me an opinion on this idea?
As long as you start your bot in the position nearest the ramp, this should be doable, either as dead-reckoning, or with simple feedback (i.e. 'drive towards ramp until you detect the ramp (with a tilt meter or contact switch, for example) and then dump all the balls').

The best way to develop stuff like this is incrementally. Do something like you propose above, and then come up with improvements and alternatives. It's nice to have a "library" of autonomous functions your bot can do, so you can select one before the match (including the most impressive "sit there and look pretty" autonomous mode, 'cause sometimes you'll be in a match where that's the best strategy, since you might be teamed with other bot's whose autonomous modes and capabilities might conflict with yours).

And remember, it's often better to do one thing really well, than do a bunch of things poorly.

Good luck, and ask lots of questions. The folks here are very helpful.