Category A Crossing?
 

Most of B, C, and D obstacles can be solved with a tank drive, but these two seem a bit annoying. Any suggestions?

Re: Category A Crossing?
 

First: Don't underestimate the "easy" defenses. I guarantee that they will get folks stuck consistently through the season... Spend time prototyping and getting them right.

Second: Some of those others will require simple manipulators to lift/pull/etc.

Re: Category A Crossing?
 

Or, teamwork. Even if your team doesn't have effective manipulators for everything, good driver communication can still breach defenses.

For example, Robot A (which could be the base kitbot) goes under the low bar into the courtyard (incidentally weakening the low bar), then opens either the drawbridge or sally port. Robot B then goes bumper-to-bumper with Robot A and they both drive through to the courtyard. Robot B has crossed the defense and weakened it. Sure, you would have to do it twice, but you don't need a manipulator to cross the sally port and drawbridge. It just might take two robots.

Re: Category A Crossing?
 

What about the portcullis and the Cheval-de-Frise?

Re: Category A Crossing?
 

you just need an arm or two to push the cheval's ramps down and hold them down till you get wheels on them. Depending on how tall you are, you could use the same arm for lifting the portcullis. Main thing on the portcullis is lifting it enough to start going under, then having a smooth surface on top of your robot for it to slide over.

Re: Category A Crossing?
 

Or, if you are sufficiently short, all you need is a wedge to lift the portcullis over your robot as you drive under it.

Re: Category A Crossing?
 

My team is attempting to be able to do all of the defenses because we are concerned about this happening and another robot blocking one of the defenses. I predict that there will be a lot of teams that discover that their robot cannot go over the B and D defenses for the first time at competition.

Re: Category A Crossing?
 

I'm with Kevin. A single arm that moves up and down in front of the robot from near ground level to the height of all the fixed parts of the robot can push down one panel of the CDF, letting you drive over, and push up the Portcullis, letting you drive under. Details are left as an exercise. (We're still working out details!)

Edit: A skid plate may help on the CdF.

Re: Category A Crossing?
 

One of my partners in crime pointed out that pushing down two CdF ramps and driving over those may be better, so you don't have to worry about the skid-plate issue.

Re: Category A Crossing?
 

I suggest using a mechanism that can:
1. Lift the Portcullis
2. Press down one ramp on the Chival de Frise
3. Pull down the Drawbridge
4. Open the Sally Port
5. Scales
This can all be achieved with a mechanical arm that moves up and down from a pivot point on the robots frame, and has two hooks on the end, so that you have a hook facing each way. I would also extend for the portcullis and scale, and with some mechanical genius, it will do all of this. I hope this helped with your robot.

Re: Category A Crossing?
 

Our team just decided that "French" was the better name for the Cheval de Frise. As in, "our robot can handle French pretty easily".

Re: Category A Crossing?
 

My thought for category A was to breach another defense, then come at these the other way and push them open, then you just need to drive back through while your bot is still holding them open. I don't see why this wouldn't work.

Re: Category A Crossing?
 

I do. Take a look at the definition of Crossing, and you'll notice that the first element is that you NOT be in contact with the Defense.

Re: Category A Crossing?
 

Also, you're thinking of the drawbridge and sally port which are category C.

Re: Category A Crossing?
 

"Frenchie" might be better.

Re: Category A Crossing?
 

Not on the way up, but perhaps on the way down. Not as bad as driving into the ramp, but it could still hit things on the undercarriage.

I've referred to it somewhere in writing as the CDF or CdF. I guess it's because I grew up in the Greater New Orleans area that saying Cheval de Frise isn't that difficult. Other than that, between D&D and a year in the SCA, I think that Batter is the the only term I didn't get straight away, and I'm guessing it's a cognate of Batture, which is a relatively high area between a river and it's natural levee, so that didn't take too much work.

We're working on a mechanism that picks up, holds, and launches boulders, as well as the Portcullis and CdF (it uses the boulder as part of the manipulator). A second mechanism would handle #3 and #4. Scaling has moved to our back burner; it's 10 points per match, but it does not affect QP unless the 10 point differential changes the outcome of a match. Defeating at least four classes of defenses and getting those first 8 boulders are our #1 priority. Beyond that, boulders are an "infinite" source of points, while scaling is never more than 10 per match.

I fully concur with EricH, and was planning to post on this point this evening but this largely covers it. The point is that you have to enter the outer defenses NOT in contact with the defense. The teamwork plan may work with the sally port, but not the drawbridge unless you have an unusual angle of attack, probably including swerve or holonomic wheels. Not only have we decided not to do a fancy drive train this year, it's entirely possible that we'll go completely period on wheels and manufacture ours largely from wood planks. I love this game.

Re: Category A Crossing?
 

Alternatively, "Our robot can French pretty well"
XD

Re: Category A Crossing?
 

I believe it would be legal for you to hold the door for your teammates. Is this your interpretation as well?

Re: Category A Crossing?
 

As long as the robot doing the crossing does not touch the defense outside of the Outer Works, that should be legal.

Why would you have to do it twice? The defense is fully weakened once both robots go through

Re: Category A Crossing?
 

Nope. Where did Robot A start? In the Courtyard. Where do you have to be to start a Crossing? In the Neutral Zone, NOT in contact with a Defense. How do you Damage a Defense? Two Crossings.

This particular Crossing method will only net you one Crossing, thus one "hit" to the Defense.

Re: Category A Crossing?
 

Conversely, if you had all 3 alliance members cross at once you could eliminate that defense altogether in one go.


Personally I buy the argument that a mechanism could be created for both Category A defenses, I do not see, however, given the available expansion space and geometry of the Category A and C defenses how you could also open the Category C defenses without a second mechanism or some secondary actuation on the first mechanism.

IMO, since Category A is the only set of defenses that cannot be defeated by robot that can only drive, so prioritize mechanisms for those defenses first and if you have the extra weight after you're done, add something for Category C, otherwise just work with your alliance partners.

Re: Category A Crossing?
 

"Shovel de Fries" and say that weeeth a french accent just like a Pepe de Pewww.

Total apologies to our French FRC friends, just attempting some word association games....My last name? Lucier Yes, it is French.

Re: Category A Crossing?
 

On a return trip I open Sally Port door, here move on in partner where you'll be safe, hold on I'll be right back...Do wait for me please (I return over another easy Defense, grab a boulder as I'm not going over empty handed), join you holding the door I opened for you from the neutral side, we proceed. Sally Port Damaged. Draw Bridge is next if it's there. While you wait for me you are safe...If not we'll pick up those penalty points later from them at match end.

Re: Category A Crossing?
 

There will be a drawbridge /or/ a Sally port. Never both.

Re: Category A Crossing?
 

In our game analysis we developed a match gameplan for three types of matches:
- Quals at district event (our robot and 2 minimally functional partners)
- Elims case 1 (us and 2 pretty good partners)
- Elims case 2 (us, 1 other excellent partner and one minimally functional partner)

In all three of these gameplans, the first two actions are:
1) autonomous drive across an easy defense (score goal if technically possible)
2) open door/drawbridge for partners to drive through

This ensures that seconds into teleop we will have a minimum of 20 points on the board and 3 of the 8 required defense crossings completed, even if our partners are only boxes on wheels that can just drive.

Re: Category A Crossing?
 

Category A
Pork Cutlet (portcullis)
Cheese Fries (cheval de frise)

Category B
Root Beer Moat (moat)
Jam Tarts (ramparts)

Category C
Salad Fork (sally port)
Raw Cabbage (drawbridge)

Category D
Gumball (rock wall)
Hunger Pang (rough terrain)

Permanent Defense
Steak Tartare (low bar)

Re: Category A Crossing?
 

Surely this defense is Chicken Paillard. Or is that not an option cause it's still French? Or maybe Tostones. The Panini Press? Oh! George Foreman. That surely has to be the correct name.