Auto-balance: Wood vs real Charge Station?

We build the 1/2 charge station and put polycarb on the top to simulate the surface. Anyone have any advice on how the real charge station behaves compared to the wood team field element?

Thanks,

JMH

We have found (and have heard reports from others too), that the wooden charge station and the the real one balance fairly differently. Surprisingly enough, the real version is actually seemingly easier to balance on.

In terms of being able to physically drive on, the wooden one we’ve been using has lexan on top of it, and seems to be simulating the friction of the real one just fine.

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3 Things that became very apparent after competing at a week 1 and week 2 at the same venue:

  1. The hinge is way smoother than the wood one and requires less force.

  2. The surface is going to be absolutely marked up with black tire marks affecting the traction. The massive adoption of swerve drives this year means lots of tires being rotated in place (like when balancing) leaving skid marks.

  3. Not sure how you attached your polycarb (we glued ours), but the real field attaches them with large head rivets and they are getting scraped up and are catching on bumper material, both causing damage to bumpers, and causing resistance so the charging station folds away from you when driving at it sometimes. This especially impacted out auto-balance in later matches.

This particular field was not taken down between these two events, so I’m not sure if they plan to replace the polycarb/rivets between teardown/setup, but make sure you check it out when you arrive.

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Wooden one was way harder, our main issue was we couldn’t get the robot to tip it. We would just end up pushing the entire bridge, as we didn’t have a great method to secure it to the floor. Unless you have mecanum drive in which case I saw lots of teams slip and slide all over the real one at Kettering 2.

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We put velcro on the bottom and it stop sliding.

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Not sure there is a great answer …

We have polycarb on top of plywood at our field. We manufactured hinges to match the ones on the real field.

Originally it was difficult to tip and once it tipped the other side wouldn’t slide correctly to make it go back to balance (even with polycarb under it). The other thing we were having problems with was wheels getting stuck in the gap between the ramps and the platform. When we went to Kettering Week 0, we studied it a bit more up close and made modifications (distributed the weight a bit differently, closed the gap a bit (there are large piano hinges so the gap isn’t real) and put a chamfer on the end of the ramp to help it slide. It is better but still not quite the same.

With these changes it was good enough for us to get our auto balance coded/tested. Still went to practice matches/practice field (they had a real one there). We were able to balance even with the different feel, but a lot of that was due to how many changes we made to make it at least behave similarly.

It doesn’t take a lot of force to tip the charging station and then when you get on top it, if you get in the middle 12 inches or so, it will level out. The key is to not drive too aggressively (we drive to get 2 wheels on the ramp and then use the pigeon roll/pitch to control the driving with a simple p-controller). I think as we attempt to do more in auton, we’ll want to speed it up more and then we may need to get more sophisticated, so that we are not driving back and forth to balance.

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We’ve also found the wooden ones harder to balance on, unless they have the andymark hinge. If you have the hinge it seems to be much closer to the actual event charging stations.

I manned the practice field at Newmarket for some of the event, and it seemed like a lot of teams who had success on wood elements without lexan struggled with getting up the actual practice field element. It seemed a lot of teams couldn’t get enough traction.

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We build basically exactly what you described and found that it behaves quite similar to the real thing, though (as most others have already said), the wooden one is surprisingly harder to get on/balance.

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