Odometry when driving over obstacles vs GPS in Over under

Dear all,

We are thinking on whether it is possible to implement odometer in Over Under as if we drive over obstacles, how will it be possible to compensate for it in the algorithms. Also, is there any known way of making odometer reliable in such situations (not getting stuck on the field or the obstacles), or is it not worth it and we should get the GPS field strips and units instead (they are quite expensive though). Many thanks!

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I would suggest putting buttons on your chassis to detect the pipe and using that maintain odometry as you go over the pipe.


if you have a longer cantilever on your odometry, it should be fine.

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There is no way you can track position reliably while going over the middle pipe on the floor. If you have a sideways tracker (perpendicular to the direction of travel) it will probably get stuck as well. The probable solution here is to use a pneumatically actuated tracking system with resets after going over the middle bar. (Or, more likely, just not going over the middle bar in programming skills.


The easiest solution will cost you $200+ USD:

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I’m curious as to the purpose of tracking after crossing the barrier. I don’t believe it can be crossed in auton, and there’s not really any tasks that need auto assist this year… unless you plan on something crazy with the match loads, but a simple wall jig could outdo anything a sensor could offer in that case.

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you are right - the perpendicular tracking wheel will get stuck. Actually even in spin up it often got stuck because we were using the smallest 2.75 inch wheels and the old odom sensor

Skills autons will probably involve crossing the barrier

Ah, yes. Sorry, totally slipped my mind. GPS does seem like a good option, but I think would experiment with both and use them in parallel if possible.

i been told that the gps is not very acurate
however do people think it’s worth buying

Yeah - but it’s so expensive though :frowning:

So is it safe to assume we can drive over the center barrier? I can’t see anything in the rules that says we can not.

Our school does fundraising for world’s every year, and that is a great time to work on getting extra funds for parts, but I guess that would be a little late this year. I would recommend looking into robotics grants or sponsorships, because there are tons of companies out there looking to support robotics. For example, Roseburg Lumber, in Oregon, visits FRC competitions to hire students and hand out literal thousands of dollars in money simply for students to consider them as a job option.

Grants and sponsorships go for paying for parts in general, and I would consider the gps sensor worth it, although you should know that we have had a few burn out and had to get them replaced by Vex, creating serious wait time where you aren’t really sure what to do. Overall, in terms of robotics applying to the real world, the gps sensor provides good experience in actual application of robotics, so in that sense, yes, it’s very much worth it of you have the opportunity to consider it. It will probably also improve your competitive game :wink:

Hope this helps!

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