Catching a ball

[YCJeon772]

Our team was brainstorming some ideas today, and one idea was to make a catching mechanism that would take up quite some space on our robot. Would catching be worth getting the extra 10 points? We did some calculations and it came out as having less cycles and spending more time trying to catch the ball. It can be a good resource to have among an alliance, but it would be hard to have it on the robot with other mechanisms that would be on the robot.

[Zuelu562]

If you can flawlessly integrate it into your robot and what you do, it's quite an asset to say "gimme the ball, coach". From what you're saying, it doesn't appear like you believe your catching system is very easily integrated.

As I said, if it's not really part of your system, unless it's so simple and small, let it go.

[YCJeon772]

Alright. Did anyone think of trying to catch a ball with the same arm mechanism to pick up the balls from the ground? It would be more difficult, but could be possible to catch it in the air.

[catacon]

Originally Posted by YCJeon772

Alright. Did anyone think of trying to catch a ball with the same arm mechanism to pick up the balls from the ground? It would be more difficult, but could be possible to catch it in the air.

Yes. And that's kind of what Zuelu562 is talking about. I see no reason why you could not make an all-in-one pick-up/catching/throwing mechanism. It all comes down to how you want to play the game and your team's abilities.

[ToddF]

Our team's game analysis method comes from Den Black, described here (part 1, part 2)

Before you ever even start talking about "how" you are going to build your robot, you should be doing a similar type of analysis to decide "what" you want to do and "why" you want to do it.

This year we have prioritized catching a ball quite high on our list of robot functionality. (I can't remember off the top of my head, but it might even be higher than high goal shooting.) One of the things we did in our analysis was figure out how quickly we could perform a teleop cycle if we had no help from alliance partners. The ability to catch a ball gives us either 1 or 2 additional cycles per match.

[nixiebunny]

Originally Posted by YCJeon772

Alright. Did anyone think of trying to catch a ball with the same arm mechanism to pick up the balls from the ground? It would be more difficult, but could be possible to catch it in the air.

We considered this, and concluded that it makes more sense to have a catching mechanism on the rear of the robot and a top-roller floor pickup on the front, or somesuch.

The floor pickup is useful for retrieving balls, and can reverse its drive to be a floor spitter, to either do floor passes to other bots, or to put the ball in the low goal.

The catcher wants to be able to get balls from either human players or other bots. We will first try to make a human-tossed ball catcher, and see if it can be made big enough to accept balls from other bots. Bounce deadening is quite the thing.

Another idea, more crazy of course, is to make the ball catcher like a Venus flytrap, with wide-open hoops on the sides that close in on the ball as soon as a pressure sensor plate detects that a ball inside it.

[erniep]

So, is anyone catching (or throwing really)?? Just wondering what the thoughts are since we all are playing nice together this year.... Not that we're not nice to each other other years...it's just....well you know what I mean.

[yash101]

I came up with a design that can pick up balls from the ground, shoot (possibly full-court), pass and catch. However, it would be a hassle to get it within the dimensions because it involves completely enclosing the ball!

Check out the design here.

I haven't drawn the catching feature on it. However, just cut out a door at the top of the cage, move the conveyor belts to the side and build a hopper on top of the opening! Also, it is linear so it will also look kinda cool!

By the way, are we allowed to extend pass the chassey of the robot by, I believe 20 inches on each side, or is it just one side? If so, this is a perfectly feasible idea!!!

[redsox11]

Originally Posted by yash101

I came up with a design that can pick up balls from the ground, shoot (possibly full-court), pass and catch. However, it would be a hassle to get it within the dimensions because it involves completely enclosing the ball!

Check out the design here.

I haven't drawn the catching feature on it. However, just cut out a door at the top of the cage, move the conveyor belts to the side and build a hopper on top of the opening! Also, it is linear so it will also look kinda cool!

By the way, are we allowed to extend pass the chassey of the robot by, I believe 20 inches on each side, or is it just one side? If so, this is a perfectly feasible idea!!!

I have dreamt up a similar idea, except the full court shooting won't help you in this game per part B. And I'm 99% sure you get the 20" outside of your frame perimeter in all directions.

"A BALL is considered SCORED in an ALLIANCE’S GOAL if

A.a ROBOT causes one (1) of their ALLIANCE’S BALLS to cross completely through the opening(s) of one (1) of their ALLIANCE’S GOALS without intervening human contact,
B. the ALLIANCE ROBOT last in contact with the BALL was entirely between the TRUSS and their ALLIANCE’S HIGH GOALS, and
C. the BALL is not in contact with any ROBOT from that ALLIANCE."

[Riverdance]

Originally Posted by erniep

So, is anyone catching (or throwing really)?? Just wondering what the thoughts are since we all are playing nice together this year.... Not that we're not nice to each other other years...it's just....well you know what I mean.

"Throwing" (over the truss) can be accomplished using a shooter designed to shoot at the high goal. The truss is about a foot lower than the high goal, so any shooter made for the high goal will also be able to clear the truss.

Catching seems difficult, but what we have figured out recently is that everyone is making catching a lot harder than it has to be. The manual defines catching as "when a BALL SCORED over the TRUSS by a ROBOT’S ALLIANCE partner is POSSESSED by that ROBOT before contacting the carpet or HUMAN PLAYER" and possession as "A.“carrying", B. “herding”, C. “launching, and D. “trapping"". Thus, a catching mechanism is not entirely required unless a team has the time, space, and resources. If a robot simply places itself in the right place such that the ball will bounce off and head in the right direction at the right angle, it should theoretically count as a catch.

That said, my condolences to the poor referees who have to decide what counts as a catch, what counts as possession, and what counts as an assist.

[Hallry]

Originally Posted by Riverdance

Catching seems difficult, but what we have figured out recently is that everyone is making catching a lot harder than it has to be. The manual defines catching as "when a BALL SCORED over the TRUSS by a ROBOT’S ALLIANCE partner is POSSESSED by that ROBOT before contacting the carpet or HUMAN PLAYER" and possession as "A.“carrying", B. “herding”, C. “launching, and D. “trapping"". Thus, a catching mechanism is not entirely required unless a team has the time, space, and resources. If a robot simply places itself in the right place such that the ball will bounce off and head in the right direction at the right angle, it should theoretically count as a catch.

Er, check the blue box under that definition:

Examples of BALL interaction that are not POSSESSION are

A. “bulldozing” (inadvertently coming in contact with BALLS that happen to be in the path of the ROBOT as it moves about the FIELD) and

B. “deflecting” (being hit by a propelled BALL that bounces or rolls off the ROBOT).

A BALL that becomes unintentionally lodged on a ROBOT will be considered POSSESSED by the ROBOT. It is important to design your ROBOT so that it is impossible to inadvertently or intentionally POSSESS an opponent’s BALL.

(Emphasis mine)

Therefore, a ball bouncing off a robot placed in the right place seems to be just "deflecting," which is NOT possessing and therefore NOT a catch.

[Zealii]

You can extend 20 in in every direction but must be inside frame perimeter when match starts

[tStano]

I don't think you catch because of the extra 10 points. I think you catch because then no one has to chase down a bouncing ball that had a decent amount of energy imparted in it. Personally, unless you have enough resources to make an excellent thrower, I think its a really really good idea to concentrate on catching, even if it means you can't throw. You may not do so well in quals but I think you will see the value in elims, as it is a really quick assist.

Just make your robot a huge 5 foot tall target with 20 inch extensions, the whole thing padded to deaden the ball and some way to release it to the ground. If all else fails, you turn around and play the kind of defense where you're a 5 foot tall box that it is unlikely anyone can shoot over. This is just my personal opinion, and my team does not agree, and we will not be building this.

[yash101]

Originally Posted by tStano

I don't think you catch because of the extra 10 points. I think you catch because then no one has to chase down a bouncing ball that had a decent amount of energy imparted in it. Personally, unless you have enough resources to make an excellent thrower, I think its a really really good idea to concentrate on catching, even if it means you can't throw. You may not do so well in quals but I think you will see the value in elims, as it is a really quick assist.

Just make your robot a huge 5 foot tall target with 20 inch extensions, the whole thing padded to deaden the ball and some way to release it to the ground. If all else fails, you turn around and play the kind of defense where you're a 5 foot tall box that it is unlikely anyone can shoot over. This is just my personal opinion, and my team does not agree, and we will not be building this.

If I understand you correctly, if you catch but have no way of ejecting the ball, you will screw the team because there is only one ball available at any time (of your color)

[tStano]

Originally Posted by yash101

If I understand you correctly, if you catch but have no way of ejecting the ball, you will screw the team because there is only one ball available at any time (of your color)

You have some sort of gate at the bottom of your robot that opens up, releasing the ball to the ground near a robot was my original thought on that. Sorry that it wasn't clear.

The issues I see is how easy it would be to get an opponent's ball, and the loss of auton points.