Statistics on top 20 teams?

[slavik262]

I think a lot of the questions about the robot and control system are great, but some of the programming questions leave me confused as to what can be gained by their answers.

Originally Posted by taichichuan

What language did they use?

As it's been said many times, the language used is really just a preference issue. You should really just go with whatever your team is most comfortable with. Some like the graphical environment of LabVIEW. Others like Java or C++. My team personally uses C++ because we have the most experience in it and like the flexibility, but again, the language you use should be whichever one your programmers will be most productive in.

Originally Posted by taichichuan

Threaded code or just poll in the teleop loop?

In terms of performance, a single thread will run faster since the cRIO is a single-core processor and less threads cause less time to be spent on context switching. We had a huge bug with the watchdog tripping this year because our extra threads were hogging too much CPU time. That said, you can play around with task priority or cause your tasks to sleep when they're not needed to make up for it in performance (i.e. have a task that updates your PWM outputs sleep the length of the Victor/Jaguar update speed).

Originally Posted by taichichuan

Did you use the Classmate for programming your robot or student/school supplied computers?

I'm confused how this has anything to do with how a team would perform. I guess I'm assuming this poll is to see what can be learned from the top 20 teams so that other teams can use this knowledge to become better themselves.

[gvarndell]

Originally Posted by slavik262

In terms of performance, a single thread will run faster since the cRIO is a single-core processor and less threads cause less time to be spent on context switching.

This is a too simplistic view of the issue.
Yes, there is some weight associated context switching.
But if a single thread polls for some event for even 3 milliseconds, that wasted time is nowhere near recovered by avoiding context switches.

[slavik262]

Originally Posted by gvarndell

This is a too simplistic view of the issue.
Yes, there is some weight associated context switching.
But if a single thread polls for some event for even 3 milliseconds, that wasted time is nowhere near recovered by avoiding context switches.

You didn't account for the rest of my post. As I said, depending on what you do with those threads affects performance. Obviously you'd want a separate thread if you're blocking for some input. Besides, that wasn't the overall point of my post.

[Chris is me]

I don't know if this is a Top 20 statistic or not, but there was not a single mecanum drive robot on Einstein this year. I won $10 when that happened.

I bet you'll find that almost all of them used roughtop or wedgetop tread in their robot, at least 4 CIMs (I don't think any of the 6 motor teams made the top 20), and they had good possession.

I also think though, that you need to figure out what is causation and what's simple correlation.

[Tom Bottiglieri]

Originally Posted by Chris is me

I don't know if this is a Top 20 statistic or not, but there was not a single mecanum drive robot on Einstein this year. I won $10 when that happened.

I bet you'll find that almost all of them used roughtop or wedgetop tread in their robot, at least 4 CIMs (I don't think any of the 6 motor teams made the top 20), and they had good possession.

I also think though, that you need to figure out what is causation and what's simple correlation.

Teams with mecanum drive were almost automatically put on our "Do Not Pick" list.

[JamesBrown]

Originally Posted by Chris is me

I don't know if this is a Top 20 statistic or not, but there was not a single mecanum drive robot on Einstein this year. I won $10 when that happened.

I think it has been proven over and over again that a well designed 6/8 wheel drive train is as fast and maneuverable as mecanum. It surprises me every year that more and more teams seem to be going with mecanum designs. Mecanum wheels make for a cool demo bot (especially if you can translate and rotate simultaneously) but we are yet to see a game where they offer a real advantage (I do think they could have been a good option in this years vex game).

[Chris is me]

Fun Fact: Just looking back through 2005 (before that "no one" had mecanum), there has never, ever, ever been a mecanum drive robot on Einstein. I hope teams that consider mecanum in future years ask themselves why they think this is.

[Peter Matteson]

Originally Posted by Chris is me

Fun Fact: Just looking back through 2005 (before that "no one" had mecanum), there has never, ever, ever been a mecanum drive robot on Einstein. I hope teams that consider mecanum in future years ask themselves why they think this is.

We said the same thing about wide bodies and Einstein in 2009 and 11 out of 12 robots were widebody that year.

Just because the game where mechanum makes sense hasn't happened yet doesn't mean there will never be one. It's a simple design trade that you can do when determining your team's strategy. Just because you can make something does't mean you should if you look at the big picture.

[Chris is me]

Originally Posted by Peter Matteson

We said the same thing about wide bodies and Einstein in 2009 and 11 out of 12 robots were widebody that year.

Just because the game where mechanum makes sense hasn't happened yet doesn't mean there will never be one. It's a simple design trade that you can do when determining your team's strategy. Just because you can make something does't mean you should if you look at the big picture.

I didn't mean to imply "never will there be one" or "mecanum is always bad". I just think when teams make such a decision, they should ask themselves why this year will be different than previous years.

[Peter Matteson]

Originally Posted by Chris is me

I didn't mean to imply "never will there be one" or "mecanum is always bad". I just think when teams make such a decision, they should ask themselves why this year will be different than previous years.

That was my point as well.

[thefro526]

Originally Posted by Chris is me

Fun Fact: Just looking back through 2005 (before that "no one" had mecanum), there has never, ever, ever been a mecanum drive robot on Einstein. I hope teams that consider mecanum in future years ask themselves why they think this is.

Oh, and my favorite Fun-Fact: There has only been one 6WD Swerve Drive in the history of FIRST... And it went to Einstein.

Also, there have been a quite a few flop bots on Einstein as well: 71 in 2002, 67 in 2004, 67 in 2005, and 16 in 2008. Looks like they've been spaced out an average of 2 years each... Does that mean we're overdue for a Flop bot to go to Einstein? Hopefully they're legal in 2011.

[Chris is me]

Originally Posted by thefro526

Oh, and my favorite Fun-Fact: There has only been one 6WD Swerve Drive in the history of FIRST... And it went to Einstein.

Also, there have been a quite a few flop bots on Einstein as well: 71 in 2002, 67 in 2005, and 16 in 2008. Funny thing is that they've been spaced out 3 years each... Maybe we'll see a flop bot on Einstein in 2011?

You forgot 67 in 2004, which kind of wrecks your pattern a little.

[thefro526]

Originally Posted by Chris is me

You forgot 67 in 2004, which kind of wrecks your pattern a little.

I edited my post to reflect this.

Hopefully the rules won't be overly restrictive and flop bots will be legal next year.

[TEE]

Originally Posted by thefro526

Oh, and my favorite Fun-Fact: There has only been one 6WD Swerve Drive in the history of FIRST... And it went to Einstein.

Which team and which year?

[NickE]

Originally Posted by TEE

Which team and which year?

1625 2010