2016 - FIRST Stronghold
The Game:
The game is played by two alliances of up to three teams each, and involves breaching the opponents' defenses, known as outer work, as well as capturing their tower by first firing "boulders" (small foam balls) at it, and then surrounding or scaling the tower using a singular rung on the tower wall. Points are scored by crossing elements of the tower's outer works, shooting boulders into the opposing tower's five goals in order to lower the tower strength, and by surrounding and scaling the tower.
Chassis and Drivetrain:
One of the top priorities for our robot this year was to have a strong drivetrain that would be capable of crossing many of the defenses while being able to traverse the field quickly, push other robots, and resist pushing. To accomplish these objectives, the robot was designed for a six-wheel west coast style drive train with six 8 inch pneumatic wheels.
Game Animation:
Boulder Control (Mechanical "Lance"):
Next on the priority list was the ability to manipulate boulders. This is accomplished via a mechanism appropriately nicknamed "the lance", a roller collector to pull the ball in with inverted ramps to help the front of the robot clear the defenses while driving over them. Our robot is also able to score in the high goal using a hooded flywheel shooter, spinning at 11,000 RPM so as to eliminate the effects of variability between the different boulders.
New and Interesting:
This year's game had a win/loss system, and the ranking system depended on how many ranking points were scored during all of the playoff matches. Ranking points could either be scored by having 4 out of 5 defenses completely damaged, making the defenses breached. Breaching defenses is considered one ranking point, while having all robots scale the opposing tower's batter at the end of the match is also considered one ranking point. In addition, one robot from each alliance can be placed in the opposing alliance's side of the field, which the robot is considered a "spy bot."
Defense Crossing Mechanism:
The final mechanisms on this year's robot are a set of passive ramps for raising the portcullis, a defense that operates somewhat like a sliding garage door. These mechanisms, nicknamed "the tomahawks" after a similar mechanism used by another team, allow the robot to raise the portcullis simply by driving up to it and pushing with the angled part of the ramp. These "tomahawks" can also be used to cross the "cheval du frise", which is basically an alternate-facing four bridge contraption. The "tomahawks" would have to be lowered in order to also lower the two upper-facing bridges. Combined, these features also had to be shorter than 14 inches so that the robot could pass underneath another defense (the low bar), allowing the robot quick access to the side of the field with the opponent's tower. Packaging these mechanisms into such a small space was quite a design challenge, and gives the robot its distinct look. Due to its resemblance to a scorpion when the lance is lowered and the tomahawks are raised, as well as the team's general space theme, the robot has been named "Scorpio" after the constellation.