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Unread 19-01-2017, 22:16
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Re: Defensive Robots/Strategies?

Quote:
Originally Posted by garyjune View Post
Considering the shuttling and the importance of cycle times in this year's game, how effective would defensive strategies/robots be?
Would it be a better idea to defend against gear or ball scoring robots?
What design elements/components would increase a robot's defensive capability?
Would a hybrid gear + defensive robot be viable?
What would defense this game look like?
There are 2 core defensive strategies (from a general design standpoint) to consider based on the 2 volume constraints:

1) Vertical Defense- Use your robot to block potential fuel shots by choosing to build using the volume option with a focus on height (30 in. by 32 in. by 36 in. tall (~76 cm by 81 cm by 91 cm tall)).
This option is difficult to pursue for 2 reasons:
  • Most balls shot in the high efficiency goal most likely follow a steep trajectory that your 36 in. height limit may not be able to block.
  • If your robot is able to block shots, getting your robot in position to block will be quite difficult, and will require manueverability that our robots may not be capable of. Well trained drivers are advised for this strategy in particular.

2) Horizontal Defense- Use your robot to effectively pin opponents by selecting the volume option with a focus on width (36 in. by 40 in. by 24 in. tall (~91 cm by 101 cm by 60 cm tall)).
  • The greater width of this design allows for greater blockage in tight spaces. Here are the rules for pinning:
G11.There’s a 5-count on pins. ROBOTS may not pin an opponent’s ROBOT for more than five (5)
seconds. A ROBOT will be considered pinned until the ROBOTS have separated by at least six
(6) feet. The pinning ROBOT(s) must then wait for at least three (3) seconds before attempting to
pin the same ROBOT again. Pinning is transitory through other objects. If the pinned ROBOT
chases the pinning ROBOT upon retreat, the pinning ROBOT will not be penalized, and the pin
will be considered complete.
  • This strategy takes a more contact-centered approach to interfering with shots; since shooting into the high efficiency goal will be such a challenge for teams this year, any light interference to a robot setting up for a shot may be enough to cause the opponent to miss. If you take this route, be mindful of the rules regarding contact:
G08. Don’t tear others down to lift yourself up. Strategies aimed at the destruction or inhibition of
ROBOTS via attachment, damage, tipping, entanglements, or deliberately putting a GEAR on an
opponent’s ROBOT are not allowed.
G09. Stay out of other ROBOTS. Initiating deliberate or damaging contact with an opponent ROBOT
on or inside the vertical extension of its FRAME PERIMETER is not allowed.
In terms of contact, both vertical and horizontal builds should be equally effective, but the width of the horizontal should be more effective for pinning.

In regards to height, the distance from the ground to the top of the high efficiency is roughly 27 in. The maximum height for a vertical bot is 36 in. and for a horizontal bot is 24 in. The horizontal bot should semi-effectively block shots into the low efficiency goal, so this is something to consider when picking a strategy.

In summary, your most viable option is probably to pursue interfering with ball-shooting robots. They are easier to throw off, as many teams seem to be implementing safeguards against gears falling off.
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Unread 23-01-2017, 22:31
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Re: Defensive Robots/Strategies?

We reviewed some core defensive strategies in our video update of weeks 1 & 2, so we recommend your team checks this out to see how other teams are implementing some of these strategies!

https://youtu.be/PJhMr0CW83s

Last edited by SMR Vault : 24-01-2017 at 08:23.
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Unread 23-01-2017, 22:48
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Re: Defensive Robots/Strategies?

The field this year has some semblance to Ultimate Ascent's field, with large field objects creating chokepoints. The chokepoints this year are the two corridors where robots can exit their key.

Optimally played defense will make it extremely difficult for boiler-scoring robots to leave the key after their cycle, as IMO, playing defense on intaking robots is more important than defense on scoring robots, as accuracy matters less than volume of fuel fired.

A blue robot shifting between these two positions can significantly disrupt an opponent's cycle time, and even has the potential to entirely lock them out of acquiring new gears or fuel to cycle.

http://imgur.com/a/NA1uK
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Unread 02-02-2017, 15:00
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Re: Defensive Robots/Strategies?

Quote:
Originally Posted by SMR Vault View Post
There are 2 core defensive strategies (from a general design standpoint) to consider based on the 2 volume constraints:
G11.There’s a 5-count on pins. ROBOTS may not pin an opponent’s ROBOT for more than five (5)
seconds. A ROBOT will be considered pinned until the ROBOTS have separated by at least six
(6) feet. The pinning ROBOT(s) must then wait for at least three (3) seconds before attempting to
pin the same ROBOT again. Pinning is transitory through other objects. If the pinned ROBOT
chases the pinning ROBOT upon retreat, the pinning ROBOT will not be penalized, and the pin
will be considered complete.
A question around pinning vs contact. G11 defines pinning this way:

"There is no FIRST® Robotics Competition specific definition of pin, so a general definition applies; “to prevent or stop something from moving.” As a result, contact is not required for pinning to occur. For example, a ROBOT parked right behind an opponent that is between dividers could be considered pinning because the dividers and the parked ROBOT prevent the opponent from moving."

So would contacting a robot for a period of longer that a 5 count be allowed assuming both robots were moving? Such as in the case of continued bumping or pushing?
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Unread 02-02-2017, 15:13
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Re: Defensive Robots/Strategies?

Quote:
Originally Posted by bmammen View Post
[size="3"]So would contacting a robot for a period of longer that a 5 count be allowed assuming both robots were moving? Such as in the case of continued bumping or pushing?
First off, this is a hypothetical situation, therefore is dependent on the situation and the referees during the match.

But imagine this scenario: Robot A is moving towards some point on the field to score points. Robot B wants to play defense on them, and so Robot B drives headlong into Robot A to prevent them from scoring. Both robots are in an open area, pushing head to head and neither are moving for over 5 seconds. This is typically not considered a pin. While neither robot is moving, Robot A could, at any time, throw it in reverse and try an alternate route. Robot B is preventing Robot A from getting to their destination via the most direct path. They are not preventing them from moving at all.

Now imagine this: Robot A has just scored, has one end against a wall or some other obstacle, and wants to drive back tot he other end of the field to reload whatever scoring piece. Robot B wants to play defense. Robot B does this by driving headlong into Robot A, driving it into the wall. Neither robot is moving for over 5 seconds. This would typically be considered a pin. Robot B is preventing Robot A from moving whatsoever and would be in violation of G11.

While that doesn't directly answer your question, you should be able to draw the correct conclusion form that.
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Last edited by Cothron Theiss : 02-02-2017 at 20:14.
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