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-   -   Is your robot defense ready? (http://www.chiefdelphi.com/forums/showthread.php?t=127247)

jvriezen 26-02-2014 18:53

Re: Is your robot defense ready?
 
If the red ball (or 2 or 3) is on the floor, and two blue bots can take turns hitting it (or hitting red bots trying to pick it up) to keep it on the floor and out of possession by red bots-- and one blue bot can make cycles without ever putting the blue ball on the floor (or holding it precariously in front of itself) then blue can win (albeit with less assists than they might like.)

I think a very competitive bot design is one that can get loaded in a secure hopper above the frame by a human (bot preferably not needing to be stationed at the field wall to still reliably receive), then truss toss and catch in its own hopper reliably (I know, no catch points for that) and then score, preferably 10 pts.

This bot can score 20 pts (and one assist -- since a solo run is one assist) on very fast cycles with low risk of loss of ball control, with the only effective defense being bots getting in the way and/or playing goalie. The bot's two partners can play full on defense- taking turns bumping the ball in the wrong direction and significantly slow down any cycle strategy that puts the ball on the floor to pass or where its easy to have a bot lose the ball via a strong hit due to insecure possession.

All three human players in alliance station can speed up cycles -- one at pedestal, one at corner and one at inbounding location -- ball is tossed from player to player to inbound as quickly as possible.

As long as the team is not too far behind after auto, it should be able to get/keep ahead with a robust, fast, low scoring cycle against a largely disruptable strategy that puts the ball at high risk of possession loss.

The top teams/alliances will have full control/carry-possession of their own ball and will control (but not possess) their opponents ball as much as possible. If you can't guarantee a reliable CATCH or a reliable self or human catch or human catch after a TRUSS, its probably not going to be worth doing the TRUSS, if your opponents are playing smart.

xXhunter47Xx 26-02-2014 18:55

Re: Is your robot defense ready?
 
Quote:

Originally Posted by BBray_T1296 (Post 1350190)
Unless the defense is summed up by a shutdown goalie bot that thwarts ~2 of your auto balls and a large percentage of teleop shots

Truss shots yo. There's no way you have a blocker that's within the height requirements that can block the parabolic arch of a truss shot.

Abhishek R 26-02-2014 19:07

Re: Is your robot defense ready?
 
Quote:

Originally Posted by xXhunter47Xx (Post 1350195)
Truss shots yo. There's no way you have a blocker that's within the height requirements that can block the parabolic arch of a truss shot.

Height requirements in the goalie zone?

Bob Steele 26-02-2014 19:14

Re: Is your robot defense ready?
 
Quote:

Originally Posted by jvriezen (Post 1350194)


All three human players in alliance station can speed up cycles -- one at pedestal, one at corner and one at inbounding location -- ball is tossed from player to player to inbound as quickly as possible.

I thought there would be only one human player in the alliance station. Two are stationed up by the truss in those positions. I also note that human players cannot pass the ball between each other from station to station. Now... that was assuming human players were dispersed on the field and not all behind the alliance area.

Anyone else want to chime in on this? Can an alliance use all of its alliance human players in the drive station area? Would you want to?

G8
Each TEAM member must be in designated areas:

COACHES and DRIVERS must be in the ALLIANCE STATION and behind the STARTING LINE.
HUMAN PLAYERS must be either in one of their HUMAN PLAYER AREAS or in the ALLIANCE STATION and behind the STARTING LINE.

G38
HUMAN PLAYERS may not pass the BALL to a HUMAN PLAYER in another HUMAN PLAYER AREA (passing the BALL within an ALLIANCE STATION or HUMAN PLAYER AREA is permitted).

BBray_T1296 26-02-2014 19:14

Re: Is your robot defense ready?
 
Quote:

Originally Posted by xXhunter47Xx (Post 1350195)
Truss shots yo. There's no way you have a blocker that's within the height requirements that can block the parabolic arch of a truss shot.

If they can never complete a cycle (blocked in the high AND low goal) all you get is 10 points (20 for catch).

John is right though, assist points win 1st seed

xXhunter47Xx 26-02-2014 19:29

Re: Is your robot defense ready?
 
Quote:

Originally Posted by Abhishek R (Post 1350201)
Height requirements in the goalie zone?

yeah but that's goalie zone, blocking a high goal shot or low goal shot. A truss shot is in the middle of the field, not in the goalie zone. You can get 10 points for shooting a truss shot even if the cycle is not completed.

Quote:

Originally Posted by BBray_T1296 (Post 1350205)
If they can never complete a cycle (blocked in the high AND low goal) all you get is 10 points (20 for catch).

John is right though, assist points win regionals

The point of me saying that is that a goalie cannot effectively block a truss shot, meaning it's not exactly effective to do hot zone auton with all 3 balls, move forward, and then in teleop shutdown the goals. Truss shots can give you the same amount of points as a high goal shot alone.

TikiTech 26-02-2014 19:51

Re: Is your robot defense ready?
 
Quote:

Originally Posted by magnets (Post 1350167)
I'm not too concerned about getting pushed around or breaking our attachment, but I'm actually worried about breaking another robot. We've got a big heavy catching thing that expands around our robot that won't break. If we go full speed into a robot's intake, there are several I've seen on here that I'm sure we'll break right off. We're making sure to bring our intake in if it's not in use when we play.

We figured this could be an issue and went with 1/8" - 1"x2" tubing on our collector. Just in case, we made a second one to bring as our withholding allowance. In addition we really worked hard on making our frame and drivetrain very robust. We plan on playing the middle and hitting hard too! And you definitely have to bring in those intakes when not in use..

Good luck to everyone!

Aloha

Sarakiro 26-02-2014 20:04

Re: Is your robot defense ready?
 
Quote:

Originally Posted by Ronnie314 (Post 1350151)
I remember about week 3 or so I saw a team post a video of a "shock" type device that let their intake move side to side a fair amount and still maintain functionality, that will be key.

**Intake down, robot drives into it, your gunna have a bad day** :eek:

1676 recommends some steel cable and a solid steel bar where applicable... :)

RonnieS 26-02-2014 20:05

Re: Is your robot defense ready?
 
Quote:

Originally Posted by BBray_T1296 (Post 1350186)
Yes. All of our perimeter protrusions are structurally reinforced with 1"x2" box tubing (1/8" wall and currently not cheese-holed either) with the pivot of the intake made from 3/4" diam steel axle. We spared no weight in protecting our attachments

Just because you make something very solid does not mean it couldn't possibly be bent. Think, if a robot hit this arm at 17 fps and it gets bent, will it still function?

wesbass23 26-02-2014 20:12

Re: Is your robot defense ready?
 
Quote:

Originally Posted by xXhunter47Xx (Post 1350211)
yeah but that's goalie zone, blocking a high goal shot or low goal shot. A truss shot is in the middle of the field, not in the goalie zone. You can get 10 points for shooting a truss shot even if the cycle is not completed.


The point of me saying that is that a goalie cannot effectively block a truss shot, meaning it's not exactly effective to do hot zone auton with all 3 balls, move forward, and then in teleop shutdown the goals. Truss shots can give you the same amount of points as a high goal shot alone.

You can only get a max of 20 points (truss and catch) before actually scoring the ball. So if you never complete that cycle you will max out at autonomous plus 20. It is entirely possible to to get ahead in auto and never have to score again to win.

Daniel_LaFleur 26-02-2014 20:13

Re: Is your robot defense ready?
 
I truly believe this will be the year of the broken intake.

Most of the RI3D style bots must extend their intake before shooting. With all the defense that will be played this year, I see many intakes getting damaged.

I hope teams bring spares.

PandaHatMan 26-02-2014 20:17

Re: Is your robot defense ready?
 
Our team is definitely ready for defense-heavy matches. For wheels, we have 6" diameter, 2" wide blue nitrile wheels with 3-CIM ball shifters from Vex Pro. The top speed is around 17 feet per second. Crossing the field (driving 45' takes 3.25 seconds). We can push last years robot sideways.

Check out our reveal video.

Caleb Sykes 26-02-2014 21:38

Re: Is your robot defense ready?
 
Quote:

Originally Posted by Bob Steele (Post 1350204)
I thought there would be only one human player in the alliance station. Two are stationed up by the truss in those positions. I also note that human players cannot pass the ball between each other from station to station. Now... that was assuming human players were dispersed on the field and not all behind the alliance area.

Anyone else want to chime in on this? Can an alliance use all of its alliance human players in the drive station area? Would you want to?

G8
Each TEAM member must be in designated areas:

COACHES and DRIVERS must be in the ALLIANCE STATION and behind the STARTING LINE.
HUMAN PLAYERS must be either in one of their HUMAN PLAYER AREAS or in the ALLIANCE STATION and behind the STARTING LINE.

G38
HUMAN PLAYERS may not pass the BALL to a HUMAN PLAYER in another HUMAN PLAYER AREA (passing the BALL within an ALLIANCE STATION or HUMAN PLAYER AREA is permitted).

Can you put all of your alliance members in the drive station area: absolutely. The rules you quoted answer this.
Would you want to do this: I wouldn't.

In my mind, there are some good plays that could involve human players in the far human player areas. Also, if you have any robot that is planning to throw the ball, you should have a human player in each of the far zones in case the ball goes out of play.

The only scenario in which I would feel safe putting all 3 human players in the drive station area would be if my alliance did not plan to ever throw the ball during the match. You might (being optimistic here) be able to save two seconds by passing the ball between players in the drive station area. However, there is more potential chaos involved by doing this. What if a coach gets in the way of the pass? What if an opponent's just-scored ball flies in and hits the ball that is being passed? Then your alliance waits for 10 seconds as the ball bounces around out of your reach until a volunteer gets the ball for you and returns it to the human players. In my mind, it's just not worth the few seconds saved per match to take one or more human players out of the far zones.

Boe 26-02-2014 21:45

Re: Is your robot defense ready?
 
Quote:

Originally Posted by Sarakiro (Post 1350241)
1676 recommends some steel cable and a solid steel bar where applicable... :)

No need for heavy steel, just need a few pieces of polycarb
http://www.fightingcalculators.org/b...r-frustration/
:)

Samwaldo 26-02-2014 21:54

Re: Is your robot defense ready?
 
Our solution to defense :
- 3cim vexpro single speed, single reduction gearbox
- 4 inch wheels
- 1/4 clearance.
- EXTREMELY low center of gravity.

We proved at suffield shakedown and in our shop, we have both the speed and torque. When we were at suffield, we didnt realize how much defense would be played while waiting for your turn with the ball. Glad we prepared to be defense though!


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