Observations from REX Competition

Hey,

So I found 3 qualification match videos from the REX tournament.

http://www.youtube.com/watch?v=tQ9DevpzKuA

http://www.youtube.com/watch?v=sGa8IFG-vWY

http://www.youtube.com/watch?v=vGtKvKTnoYk

None of them are really good, however, the third one is the most interesting.

Enjoy :stuck_out_tongue:

The high score for the REX Toss up was around 57 if I am correct. This is about what everyone was expecting for early season, and while none of the videos showed ā€œreally goodā€ matches, the fact remains that these teams had robots ready to play by June 15, and have not likely had much if any time to practice.

Looking at the high score really make your realize the importance of a good autonomous and hanging high with a ball.

Yeah, I saw that, if I was the referee I would have given the autonomous win to the blue alliance after that interaction with the robot (catching it as it began to tip while leaving the alliance tile).

All-in all I would say it was as good as I expected to see, and knowing some of these teams I expect some really great robots as the season progresses.

I see 944 is using stand offs for the big ball intake, that’s what we did as well, but it looks like they might be able to pick up more than one big ball at a time which is our limit.

hahaha your telling me!
Those were some brutal matches! I didn’t expect the robot on robot melee to be so…idk harsh? I think it was the first video where the claw bot just totally pushed around robots intentionally trying to flip them over :stuck_out_tongue: hahah that was a good thing to note…

Yeah, I saw several things I am sure would result in a DQ in most tournaments, but I am sure this was more of a scrimmage. No doubt the teams that attended learned a lot that will benefit them as they continue their builds and prepare for the season ahead.

I definitely saw a lot of my ideas come to life and work :slight_smile: I also saw (like SBD) lots of mishaps in the gameplay. The bump does not look very hard to get over. This looks like an awesome game!

Team 24A, 24B and 24Z attended. The event was well run by Team 1727 and their volunteers. It is always fun to see the game played early in the season and have an opportunity to try ideas in a competitive environment. I was amazed at the level of detail and amount of effort put into the robots this early in the season.
Some observations:

-The hump is more of a challenge than some may think. Just because your robot clears it does not mean you will get over it easily.

-Another thread that Karthik answered stated that the large balls should not fit under the bridge. There were some matches where the large balls were pushed far enough under (approx. half way) that the Refs had to carefully determine which side of the line had the majority of the ball. It seems that with a strong drive train a ball could be pushed all the way under in the middle where the PVC pipe will deflect the most. I suspect the balls were inflated to the lower end of the diameter range at this event, but I did not confirm that.

-I saw one robot that could high hang reliably, but that was all it could do (at least I didn’t see it do anything else). A few other multipurpose robots did attempt hanging but did not seem reliable.

-The most significant item is the fact that the field is very crowded with 4 robots and all of the game objects. In particular, we saw several matches where there was so much congestion in the goal zone that it reached gridlock. Nobody could move. It appeared to be a result of normal, legal game play and not the result of any team or alliance pinning or entrapping robots. Pinning/entrapment calls this year could very tricky in cases like this. The Refs may need to try to remember the progression of events in a match starting 20 or 30 seconds back and determine whether anyone actually did something in particular that lead to grid lock or if it was just due to normal game play and game objects moving around. In some cases all 4 robots were in the mess and couldn’t move, so who is pinning and who is pinned? It was not at all clear and was a challenge for the Refs. The lesson here is to build a robot that can maneuver tight spaces.

-In the past rules stated that a game object touched by a robot of the same color was not scored. We noticed that the current version of the rules do not include this text. I am not sure if this was intentional or not. The lack of this rule makes a big difference. Given the crowded field as discussed above, it is possible that a robot could be touching 2 or more of its game objects at the end of the match. I am concerned that if this rule were reinstated it could lead some rough game play at the end of the match. Teams will see benefit in shoving opponents and holding them against game objects in the last few seconds of a match. Probably not a good practice to encourage. So the lack of the rule this year may be a good choice.

All three of those matches have a 944 team! 944a definitely did the best out of all of us on saturday, coming in first in the qualification rounds, but 944b, 944c, and 24b (who placed last during qualifications through some crazy fluke or something) ended up taking them out in the quarter finals, so it was a fun day for sure! The claw bot that was pushing the other robots is 944c. It has an 8 motor base, so it is kind of meant to push. I don’t think you can say that there were any attempts at intentional tipping though, it clearly shows 944c trying to back away from a pin, but the robots got slightly entangled. Either way, it was a very fun day and it gave us a lot of ideas for future robot designs!

This was a great example of where going only on the rankings for alliance selection does not always work well. The 944B, 944C and 24B alliance (Alliance #8) was made up of the 13th, 16th and 35th ranked teams (out of 35 teams). They made it all the way to the Finals. The looks on people’s faces were priceless when the two 944 teams picked 24B. Why would anyone pick a 0-7, team who is ranked last? Well 24B had a good design with some problems that they worked out over the course of the day, and finally had a great performing robot right before alliance selection, and 944B and 944C saw the potential. Rankings don’t always tell the whole story.

Yeah, I think I can say, on behalf of 944b, that you guys were great to work with! I honestly couldn’t figure out how 24b came in last with such a great robot lol. I will admit, we at 944b have definitely taken some aspects of 24b into consideration for future designs to be implemented in future robots. See you guys at states!

Autonomous is very important. The current challenge will be coming up with a reliable autonomous that can score more than 12 points (two large and one bucky in goal) for a single robot.

The balls were overinflated and that was announced at driver meeting… NOTE to all, you CANNOT get the balls to regulation size without using a pump of some kind (which we did not have handy). We helped REX setup and discovered this the night before.

This was my biggest takeaway. We are in match 57 in the videos above and you can see the congestion at the end. We had two refs standing right next to our bot and another one fighting near a goal, watching to see if there was actual pinning going on. Be Prepared!

Overall this was a great event and we had a great time participating.

Stan

We’re planning on doing 25 for Auton in the middle zone this year, and 20 in the Hanging Zone. Has anyone come up with a plan that scores more? Not asking for your plan, obviously, just kind of curious if I’m underestimating what people want to do in Autonomous.

Oh, and 944? The implementation of your large ball intake is freaking genius. I spent two weeks staring at parts coming up with nothing but an oversized claw. GREAT idea.

As much as I would like to thank you, most of the credit for that should got to the aperture robotics guys. We only slightly modified an idea that they released to the forums. Thanks anyway though! We were thinking of something a bit similar, but their idea is a bit more simple so, we decided it would be more efficient to use theirs and change it a bit.

Did you try it with stanchions on the spinning parts instead of those flaps? I’m interested in making a set of those to see if they let us do what we wanted to.

I am not completely sure what a stanchion is lol, sorry. If you are referring to what my team and I call standoffs, I am sure they would work, but we figured that they would be too stiff and would put us at risk of popping large balls. We didn’t really test this because we didn’t want to risk it.

We did a similar device with 2 standoffs on each side with the small rubber intake wheels and it works great as well. We had initially used the rubber links at the bottom of the standoffs but they gave too much flex. The balls compress enough to allow a rigid mounting of the rollers. When you run out of motors to use you really have to figure out a simple way to do things! You can cap with this design as well, but picking up large balls to hang and descore was our main goal.

I think that clawbot will do it’s share of scoring/descoring once the driver has some practice as well.

Yes, this is where the idea originated. http://youtu.be/YIx0t8bYvVA

Our idea is similar. We just have ours mounted out a little farther so the intake doesn’t bend. I think everyones ideas are pretty similar.

The game as a whole seems very congested especially towards the end of the matches when everyone is trying to move. All of the bots look good considering how early in the season it is. Great work!

I must agree with the entirety of this post. It is a very fun game though. It seems a little more light-hearted then sack attack for some reason, but that might just be me. I had a really fun time just playing the matches and scoring points. It may just be because there are more places to score, or the fact that it is early in the season, but either way, it is a very enjoyable game!

its a little more ā€œlight-heartedā€ compared to sack attack because its June :stuck_out_tongue:
i bet toss up worlds will be just as exciting as any other game :slight_smile: