I had a bit of an odd team situation for this year. For the first 8 days of the year, I worked with 1714 as they went through their game strategy and initial concept design. After that, I went back to school and met with 2791, having already picked their strategy. It was a unique opportunity to see two different approaches to the same problem. Neither team collaborated and I didn’t tell 2791 what 1714 was doing or anything like that.

Keep in mind I have a bit of a case of “More Robotics fog”, so I may misremember key details of 1714’s design process. 😛 I also don’t know that much about the competition robot other than what I’ve seen and asked about. I can tell you they had shifters and a vacuum but I can’t tell you what was used to machine exactly what.

2791 on the left, 1714 on the right.

Strategy

Both teams leaned toward a midfield oriented robot. Oddly enough we had very similar strategic analyses as I left 1714. We figured that “any random robot” could be put in the front, and that a lot of teams would be able to inaccurately clear out of the back zone and then “defend” for the rest of the match, so the focus would be on a midfield bot that could control balls and leave the zone if needed. The midfield bot would be the most versitale for qualifications; it could start in the back zone and advance if we have to. It could advance to the front to clean up if need be. In the eliminations, grabbing a back zone 3 and D and a front zone cleaner would be very easy to do. The obvious choice would be to play the midfield first, as that is where the balls go.

We determined the bare minimum of teams that changed zones on any alliance would be 1. Since this was in our minds a requirement to beat any given alliance, it became mandatory for our teams to be that team that changes zones.

The midfield strategy we thought would call for a lot of pushing. Since the balls in the game would all return to the same spot, we all would have to fight for position under that spot. As a result both teams quickly decided on high traction drives. With the game encouraging defense in a lot of ways despite the seeding system, a mecanum drive just wasn’t an option either team wanted to pursue. A serious discussion of the swerve drive was had on 1714, but because the prototype wasn’t quite ready for prime time even on a flat field, it was abandoned.

Differences in Design

Right here is where 1714 and 2791 diverged. Oddly enough, it’s when I started working with 2791. 1714 built a 6 wheel prototype and figured out a configuration that worked over the bump. 2791 went for a simple 8 wheel configuration apparently using some CAD to figure out how 8 wheels would react better on the bump than 6. As I left, 1714 was working on roller and vacuum prototypes, but 2791 heard from 1726 that the roller magnet was relatively easy so we didn’t think too much of it. Whoops. 1714 made some kind of cool kicker that used pneumatics to pull back or something, I still don’t really get it. 2791 used a pneumatic precharge that kind of worked. 1714 shifted, 2791 wanted to but couldn’t afford it.

Hanging

1714 and 2791 both strongly considered hanging, but neither did in competition. After I left, 1714 decided that they could score 2 or more balls on the ground in the last 20 seconds, so hanging would be a waste of time. 2791 thought the consistent points that hanging offered would be invaluable in some matches, so a large focus was put on it. However, no hanging mechanism 2791 made worked in competition, within weight.

I was “on the fence” between the 1714 and 2791 decisions all year. Makes sense, I guess, being “on the fence” between the teams. On one hand, hanging was worth it. If Shaker hung reliably in addition to what we could do, we would have been a force at CT without a doubt. Few teams not named 469 scored 2 balls in 20 seconds on average, and a well designed hanger could go from normal configuration to points in 10. On the other hand, hanging took a ton of resources. Shaker’s ball game suffered a lot because we spent so much time working for those two points. Initially I thought it was silly that 1714 didn’t pursue hanging because I thought they didn’t think it was worth it, but now I see the wisdom of what they did. Doing “one thing well” is always better than two things badly.

At Competition

Both teams eventually shifted to a primarily front zone role. 1714 found that they were much more effective in the front though they could play the mid zone as well. However their consistency in front was their biggest asset. 2791 found that their kicker kind of sucked at getting balls over the bump consistently, and with last minute vacuums and lexan guards they played the front zone quickly and decently, so they switched to only the front zone. Both teams made the same strategy changes despite different looking robots.

1714 had a great run all year, starting out at Wisconsin as the first pick of Wildstang. Ultimately they were bested in the eliminations; Wildstang had to juggle playing both defense and midfielder, and 1714 was subject to HEAVY defense that made them take longer to score the balls in their home zone. Since they had balls in the home zone, and since 111 was defending, no one really contested the middle and ultimately they were narrowly bested by a strong 1732 / 2574 / 171 alliance. Then they went to Minnesota and dominated the event. There’s no video so I don’t know anything about their run, but they were pretty clearly the bets team there from what I’ve heard. At the Championships, 1714 reached a milestone and was selected for eliminations for the first time ever (1714 just missed the cut in 2009, and in 2008 they got carried to the 7th seed), pairing up with 1305 and 230, only to be topped in the semifinals by the potent combination of 1086 and 217.

2791’s run was less great. At WPI, the robot had a ton of problems and several “nightmare matches” threw us in the odd situation where we did so badly we seeded in the top 15 or so. We ended up throwing a few matches versus 230 (the event winner) and worked to rebound on Saturday. Two great matches and we got the 7th seed and 5th captain, picked what was left in the barrel after all the good midfielders left the field by pick #2, and then fought hard against a similar alliance, losing only after 5 matches.

CT turned out a lot better, as Shaker was focused from the beginning on doing what it did best: playing front. We swept our way up the qual match ladder, winning several matches, then faced the “Friday Afternoon Curse” that always troubles us, including a 1v3 match against 1501 and 1124 that we didn’t throw. After some strong matches Saturday including setting the regional high score with 383 (until the QFs…), alliance selection came and we were the 5th captain again. 177 and 173 were still on the board thanks to the latter’s failed Classmate all Friday and the fact that somehow people still don’t get that picking 177 is a great idea no matter what. We broke into the Semifinals, but not before technical difficulty after technical difficulty; 177 took a hit that immobilized their drivetrain, 173’s arm snapped repeatedly, one of the Blue Alliance’s DOGMA counters was finicky, 177’s hang missed due to a twisted cable, Shaker’s vacuums were finicky… you name it, it happened. Anyway we ended our season here since we didn’t have a Championship qualifier; at least we ended it with a fantastic alliance.

Who was better off?

1714 without a doubt.

Advertisements