Who is using swerve for aerial assist and why
 

Good afternoon everybody,

My team members and I had a very spirited debate about weather or not swerve drive or regular tank drive (e.g. 6 or 8 wheel) would be optimal for this game over the weekend. Just wondering who has made the decision to use swerve drive this year and why. Looking forward to the answers. ::rtm::

Thanks,

Drew

Re: Who is using swerve for aerial assist and why
 

Hi there,

Although swerve drive is currently outside of our team's capabilities (we are a rookie team), I personally believe that swerve (or crab) would help greatly if your robot is an over-the-truss catching robot as you can quickly align yourself with the trajectory of the ball without having to turn first. This saves you precious seconds while the ball is in the air.

Hope that helps!

Re: Who is using swerve for aerial assist and why
 

We are looking in to swerve heavily. other then the mechanical complexity if you cant program it to its true potential then i would not recommend using it. It will take a long time to master the code and they take weeks to build.

Re: Who is using swerve for aerial assist and why
 

Why swerve over mecanum?

Re: Who is using swerve for aerial assist and why
 

Traction

Re: Who is using swerve for aerial assist and why
 

No protected shooting zone? Defense being a major part of the game?

Re: Who is using swerve for aerial assist and why
 

Swerve has a much better tactical feed back with encoders. It can use the full power of each of the cim motors, for a much higher speed/acceleration/better torque. unlike mecanum which are very easy to push in compared to almost all other types of drive trains. they can not strafe side way nearly as cleanly as a swerve can. Swerve can also drive a much more straight line. But will have a massive resource draw, even the best of teams can have a hard time building and programming them.

Re: Who is using swerve for aerial assist and why
 

Honestly, if it weren't for the traction problems, I'd almost prefer mecanum this year. Swerve is nice but can take time to change orientation, mecanum is more instant. Regardless, the ability to side strafe would definitely be handy.

Either way, our team will likely be building a tank-style drive this year.

Re: Who is using swerve for aerial assist and why
 

To quote Cory McBride, mentor of Team 254: "Swerve is never necessary."

Re: Who is using swerve for aerial assist and why
 

K. I didn't really know what swerve was...

I think I understand now.

Yeah, some of my team mates want to do mecanum this year... but I'm going to try to convince them otherwise tonight. :P

Probably going tank drive. It's easy and effective.

Your right, traction is going to be a biggy this year.

Re: Who is using swerve for aerial assist and why
 

That is a tough one to argue with. Traction would be the reason why swerve over mecanum, we are going with 8 wheels probably but I wanted to hear what CD had to say. I am however in favor of swerve being a good strategy this year and pushing the envelope as far as design so I can't say I wouldn't have liked to try swerve.

Re: Who is using swerve for aerial assist and why
 

True, swerve is never necessary. But if you're team 16, or 71, or 1717, or 1640, or some other team that has swerve pretty much down, you're probably liking your swerve drive right now. I think this would be a great year to be a team that already has a swerve drive well established.

Re: Who is using swerve for aerial assist and why
 

In my opinion, swerve is pretty much one of the most versatile drivetrains and almost always provides some form of advantage in the game each year, but the general rule of thumb (that I believe was present in 1114's strategy or drivetrain design presentation) is that if you've never done swerve before (either in offseason or regular season), don't do it. The 6 week build season is just not complementary at all to the designing, construction, and TESTING of a swerve drive.

Re: Who is using swerve for aerial assist and why
 

If you have not been playing with a swerve test bed the last month, then swerve is not for you. For teams that have done the prototyping it's still a soul searching decision. We are going with swerve again this year with some tweaks. Mill will probably start up on Thursday. The rush is on. Now the focus is on how to deal with the ball and save room for the UN-announced end game.

Re: Who is using swerve for aerial assist and why
 

Please stop encouraging this

Re: Who is using swerve for aerial assist and why
 

;)

That 8 wheel swerve is going to be mad sweet!!! :yikes:

Re: Who is using swerve for aerial assist and why
 

I am not sure why everyone is discouraging this. I believe this whole conspiracy thing is totally fake, however, no one can deny that it isn't teaching good principles. If teams are building at 75% weight, which many are, they are going to have a lot better time during the last week or so once they realize there is no endgame.

Having 20-30 pounds at the end to add support, add weights to balance, and still have a functioning robot will make crunch week a lot easier. The Team will be less stressed, judges will have an easier time, and you won't be cutting zipties to drop 1/10 lbs like we had to. Let people be misguided, it is making better, more flexible, teams.

Re: Who is using swerve for aerial assist and why
 

Our team is heavily considering an octocanum drive where we can use the mecanum drive to maneuver ourselves into position to catch/chase the balls and use 4 normal wheels when we need to line up to shoot and not be pushed around. I'm not sure how many people have considered this because I haven't seen it mentioned yet.

Re: Who is using swerve for aerial assist and why
 

Please keep the discussion of this silly conspiracy theory to its respective thread in the Rumor Mill. I don't want to have to read about it in other threads.

Re: Who is using swerve for aerial assist and why
 

I too have been considering an octanum drive to great length and feel it would be the best of both worlds. My team does not have the time or experience with swerve mechanisms to develop one in 6 weeks, however we feel that being omni directional would help us a lot. By going with an octanum drive it challenges us opposed to the past 3-4 years of a standard tank setup without having to do something overly complex.

Re: Who is using swerve for aerial assist and why
 

And finally a game made for swerve! Looking forward to seeing what the value engineering process does this year. And if you programming team makes the advances this year the way they did last year, it will be one sweet setup.

You forgot the :rolleyes: for the humor impaired....

Re: Who is using swerve for aerial assist and why
 

Octocanum seems good too, but not as good as swerve. I like strafing for catching, and the defense is going to be trying to shove you when you are trying to catch. Octocanum can't strafe and have traction at the same time, but swerve can. But I still like Octocanum for this game for a team that can come up with one without sacrificing their ability to create a well-iterated set of scoring mechanisms.

Re: Who is using swerve for aerial assist and why
 

Although it is true that you cannot have traction at the exact same time as you are strafing, once you are in position to catch it is just the push of a button and you have immense traction. I understand that it would be nice to have that traction 24/7, but for a team that doesn't have the ability to make a swerve, its gotta be the next best thing IMO.

Re: Who is using swerve for aerial assist and why
 

At the end of our season swerve both saved our team and destroyed it. We did not use that much machine time from our shop. We got funding for the development of the swerve drive alone. The biggest resorese draw was not machining or even programming but a few of our high performance students left to go machine it leaving the rest of the robot in a mad house. In the end it will leave a legacy of something much more advanced then ever before. Something to build on year in and year out.
I think we got farther with a working swerve then if we would have with a better manipulate. Plus the personal reward for completing it is something amazing.

Watch some of 16, 2481, or 2451's matches. If there ever is a year where swerve makes sense, this is it.

Re: Who is using swerve for aerial assist and why
 

You can watch some of ours to for defense

Re: Who is using swerve for aerial assist and why
 

I feel that any team capable of designing, manufacturing, programming, and driving a swerve drive-train should do so if the weight limit allows for it. That being said, there's not very many prepared to be in that category at the beginning of competition every year, which is why teams need to develop those capabilities outside of competition (which apparently takes quite some time)

Re: Who is using swerve for aerial assist and why
 

If you have ever attempted to play defense on team 16's wicked swerve drive, them you will realize how useful it is, especially in this game. the ability to orient yourself to the ball is great, where as a tank drive robot has to turn, the swerve allows them to just scoot over. But it also depends on your design plans for the game, I know a team that did swerve last year, and could've done it this year, decided to go with a design that worked for them but was heavy so they decided not to use it. Everything is custom to your team in a sense, what works for our team, may not work for another.

Re: Who is using swerve for aerial assist and why
 

Its interesting to look back and see who used swerve this year.

The Swerve list:
16
368
1717
2067
2481
2517
2936

I might be missing a few teams...

Re: Who is using swerve for aerial assist and why
 

2451, Pwnage from IL has a very nice swerve...won Midwest with it.

Re: Who is using swerve for aerial assist and why
 

Don't forget 2481! They won WI with a very nice swerve drive.

Re: Who is using swerve for aerial assist and why
 

Add 2767 Stryke Force to that list.

Re: Who is using swerve for aerial assist and why
 

And 1640

Re: Who is using swerve for aerial assist and why
 

1640 was the only one using swerve at the MAR Championships and I was thoroughly impressed. Combine that with a very accurate shooter and experienced drivers and you've got a great combination :D

Re: Who is using swerve for aerial assist and why
 

I have a question for swerve users this year:

I am interested in how many swerve users this year are 1) 4 wheel independent or not, and 2 ) how many are field-centric (using a gyro) or not and 3) and if 4 wheel independent: use 4 PID's (for steering) vs. 8 PID's (for steering and speed control), or other?

For us (2067, Apple Pi) we are 4 wheel independent, and field-centric and use only 4 PIDs finding that similar to when we used Meccanum in 2011 that careful mechanical set-up mitigates the need for speed control. We have been quite pleased with this set up so far. Though have run into issues of gyro (KOP) failure after strong hits (g-forces) (are there better Gyros that can take more g forces?) - this has not been an issue before this year - likely a reflection on the level of robot interaction this year vs. past few, any suggestions on improvements there (gyro's) are welcome.

Though we also believe that without field-centric steering, swerve drive does not buy itself in, however we know that teams we admire have different views that we would like to understand better.

For those interested in driver control preferences our driver prefers a 2 joystick set up with strafe on a KOP Logitech joystick in his left hand and a Logitech Extreme twist stick in his right hand for rotation control.

Also I am surprised, that at least on this thread, it would appear that fewer than 20 teams (<0.1%) have swerve?

Re: Who is using swerve for aerial assist and why
 

Yep Breakaway won twice without swerve this year opposed to not winning with it last year

Re: Who is using swerve for aerial assist and why
 

For us:

1) we are 4 wheel independently driven and steered.
2) we have field centric as an option we can engage on a button press if we so choose. Because of the issues with defense and all that, we haven't used it a whole lot this year. One solution we had to some of the issues was to also have the ability to reset the gyro on the fly with another button press.
3) we use 4 PIDs for just the steering positioning. We went through some evaluation for finding the best allowable tolerance to give the best response and fluidity of control. We found that tightening the tolerance up too much caused a more jerky shift in movement due to the tight snaps to wheel positions....there needed to be a bit of play to account for the dynamism of gameplay. It noticably increased our effective responsiveness to sudden desired changes in direction once we found that tolerance sweet spot.

For our control, we use the dual sticks of the xbox controller. All translation is on the left stick with all rotation on the right. We also have some driver assist functions built in to some button presses for some more complex maneuvers. We also have an orientation swap feature that allows us to immediately shift whats considered forward and reverse that our driver can use whenever he chooses. Thats in addition to the field centric option toggle and the on the fly gyro reset.

I'm also very surprised at the lack of swerve drive this year. I understand it poses some significant challenges, but the game this year lends itself to a lot of advantages from slick swerve drive control. I'd be really interested in the final tally of swerve drive teams...but, right now this does seem to be a pretty exclusive club in terms of percentages.

Re: Who is using swerve for aerial assist and why
 

Watching 2451 during the elims at Midwest was a privilege.

Re: Who is using swerve for aerial assist and why
 

Of the 13 swerves mentioned (above and below):

1 made it up to quarterfinals
4 made it up to semifinals
8 made it up to finals
7 of them won

Impressive!


16 W
http://youtu.be/-8JvuI-0f7Q

368 W
http://youtu.be/fi68AQWPtCw

1640 W
http://youtu.be/J2sRILQ-foE

1717 W
http://youtu.be/Lk8CYkMSyMs

2067 S
http://youtu.be/DkqQwtXmgbQ

2451 W
http://youtu.be/r_xAUwlJuYA

2471 W
http://youtu.be/Ij6AubTx9M4

2481 W
http://youtu.be/I4AYeJGE5ds

2506 S
http://youtu.be/Cn-AmTfuPrs

2517 S
http://youtu.be/Lpb2IiGRMD8

2767 Q
http://youtu.be/e8Xh-uh01HI

2936 S
http://youtu.be/KzB8RZ9w8H4

4143 F
http://youtu.be/sYnsHDUAo1I

Re: Who is using swerve for aerial assist and why
 

Add 4143 to the list. They were in the finals at Central Illinois. I'm fairly certain 2506 belongs on the list too. They made it to the semi-finals at Midwest.

Ours is 4 wheel independent

We do not use field-centric

We use 4 PID's for steering

This is just a small sample size of what's out there, so I would venture to guess there's something in the ball park of 50-100 teams (~2%-3.5%) with swerve this year. 200 at best (~7%).

Re: Who is using swerve for aerial assist and why
 

https://www.youtube.com/watch?v=r_xAUwlJuYA

Watching them play was a thing of beauty. They were just completely unstoppable.

Re: Who is using swerve for aerial assist and why
 

Well. I wouldn't say they won that first one entirely without swerve.
;)

Re: Who is using swerve for aerial assist and why
 

Just to point this out the video you listed we were running on 3 wheels instead of all 4. (you can see us tilting a lot) Our front left swerve was destroyed after we got entangled with another robot and recived a direct catapult shot to the module. Here is a much better video https://www.youtube.com/watch?v=Lpb2IiGRMD8

2471 also has a swerve drive.

Re: Who is using swerve for aerial assist and why
 

I would be incredibly surprised if >50 teams used swerve this year.

Re: Who is using swerve for aerial assist and why
 

You have a point there haha