I was wondering if anyone has pondered the merits of holonomic drive in a defensive situation.
Most “defensive” robots utilize powerful drive trains to push their opponents around the field to keep them from scoring. This is obviously an effective method of defense but last week at the Peachtree regional I found another.
During one of our qualifying rounds our alliance partners asked us to defend against a very strong scoring robot. At first I protested because I didn’t think our robot’s mecanum drive was up to the challenge. As the match began I found that it was incredibly easy to stay between the other robot and the rack, making it very difficult for them to score. During the match they were only able to score one tube while I was tangled in the rack.
Our robot may not have been very powerful but it was able to keep the other team from scoring. This kind of defense is not effective for all game types but for Rack and Roll it works quite well.
This type worked well last year as well, because you could get between the robot shooting and the goal. In 2005, is it my poor memory or do I not remember much defense being played?
From the LA regional (I watched a highlight match video) the Harker bot on mechanums defended against the Poofs by knocking tubes out from in front of the repeatedly. Mechanums are great for maneuverable, strategic defense… But you still can’t beat a brute force system that can politely escort any other robot across the field.
That is how we, team 1625, played defense at our regionals. We were able to push/stop most robots in 1st gear, however, it turned out to be a much better idea to block access to the rack. Especially with the maneuverability of the swerve drive.
1625 was amazing at defending 71. They used thier swerve drive to stay infront of the Beast.
Against some teams, speed can be just as valuable than power. If you can’t catch a team, you can’t push them. But you can stay infront of a team and shield them from the rack, if you have speed and not power.
We managed to keep the Technokats (:ahh: ) from scoring for most of the match. We simply put ourselves between the rack and their robot.
Another thing we developed was a strategy where the defending team stays between the rack and the opposing robot (opposing robot very close to a position to score). The two robots push against eachother and the defending robot quickly moves out of the way. The opposing robot doesn’t expect it and drives forward at full power, thus overshooting the goal. They now need to spend some more time re-aligning.
well there is another way which i found very easy to do…im with team 1555 and you dont really need all that big of a transmission …all we used was the banebots transmission you are given in the kit… well most robots this year are very easly pushed just by hitting there corners and turning them 180 degrees… this way you can take on more than 1 robot…which i was able to do many many times
From what I hear, we ended up as number one in defense on many team’s scouting lists, just because of how manueverable we were. If you turn your ramp towards them and stay in between the other robot and the rack, it’s almost like holding a poster and walking. Bonus points if you slap them-ahem-the tube with the ramp.
our holonomic drive was actualy fairly good at getting us into the way of robots trying to score, though most of the time we were the ones scoring:D
it also makes it easy to drive circles around torqued up 6 wheelers trying to play rough D.
We were able to get in Bellarmine’s way a lot, but against bots with average or greater than average pushing power, the mecanums were only useful for knocking away tubes. We got frequently pushed into the rack and it was hard to prevent good top-scorers (i.e. Beachbots) from scoring over us.
Yeah…I remember there being much stricter penalties for pushing/robot contact in 2005.
I agree… with our (648) swerve drive we were able to outmaneuver most robots with good drivetrains at MWR. We could also push a lot of robots.
I saw that 858 had a good defensive robot in the qualifiers, but one they got into the elims they were very ineffective at defending teams. Same for 1000, our partner and the number 1 seed.
We holonomic drive this year and before we got our arm to function we played d. Since we could srafe back and forth we could gaurd almost half the rack by our self. Just as long as we dont get into any pushing matches
At Lone Star Regional, team 118 (Robonauts) used a “v6 engine”
they basically put together 6 motors to create a monster v6 engine. Their arm was very quick and effective, allowing them to score a row of 8 by themselves. We team 846 had saw that video before we arrived at the regional and were somewhat curious how we were going to defend them. When our match against them finally came, we just double teamed their robot, eventually blowing out their v6, forcing them to use their backup v6.
A double team can easily force a blown engine = great defense.
During quarter final match 1 we took a hit that caused some electrical problems in the robot. Our frantic troubleshooting caused other problems and we were never fully functional the rest of the tournament. It was a struggle to get a robot out on the field after each tough match which followed. It seemed everything that could go wrong with the robot went wrong… except the V6. There was no “blown engine”… just one that came out of gear due to a hard hit in the last match.
In one of the qualifying matches at chicago we wound up with a ringer on us early in the match, so we had to play defense. While we dont have mecanum drive, we do have a crab steer which was surprisingly easy to defend with. One flaw with not necessarily mecanum but holonomic drives is they have less traction. This is one flaw that can be easily exploited, however when used as defense, if you can get inbetween the rack and the robot, there are very few teams that can score over another robot.
Now that I think about it more… 1625 played mean defense against 71 in the quarterfinals of MWR. They had crab steer and stayed between the rack and 71. Unfortunately, it wasn’t enough to keep the rest of 71’s alliance from scoring.
If the rack is defended properly by a 4/6/8 wheel drive robot, it is just as good if not better than the macanum drives. It all depends on how you try to defend.
I originally had my driver practice strafing around the circumference of the rack with the intention of scoring on the far side. This same movement was useful for defense in the end.
2005 game didn’t have much defense because there were essentially nine goals to defend.
