First team with swerve drive?

[JVN]

Originally Posted by Ether

Is there a shorter name, widely understood within the CD community, for a 4-wheel independent-steering and independent-driven drivetrain, with unlimited rotation of the wheels and sensors, and no gaps in the sensor feedback?

If not, could a longtimer here please invent one? It sure would be useful when discussing control methods.

The Unicorn drive?

[Ether]

Originally Posted by JVN

The Unicorn drive?

Well, that's what it is then, christened with JVN gravitas.

This will save me a whole lot of typing.

[AdamHeard]

The closest I know a team came to this task would be 469 in 2007.

4wd independently steered, independently driven (and 3 speed shifters).

However, it was motor in module so was not infinite rotation.

They did nail the control aspect well, which few teams with such drives do.

[Chris Hibner]

ChiefDelphi did 4wd swerve for the 1999 game, as well as the 2001 game.

[Gdeaver]

1640 did 4 wheel independent steering with each wheel independently driven and continuous rotation on all wheels with no gaps in the absolute rotary non-contact sensors and implemented a least distance algorithm to determine whether to reverse direction and rotate a little or make a longer rotation in 2010. It was a major effort but it worked and has amazing capabilities. However, we still need to work on the presentation of all those degree's of freedom to the driver. We call it the " PIVOT DRIVE". To any other team that wants to go down this path I would ask them to seriously evaluate their resources to accomplish it. A page with a little description.
http://wiki.team1640.com/index.php?t...VI_Drive_Train

Yes, I am very proud of the group of students that made this happen.

[Chris is me]

Originally Posted by Gdeaver

Yes, I am very proud of the group of students that made this happen.

And for good reason! 1640's technical achievement is both underrated and can't be understated. Especially impressive is their extensive documentation - often more valuable in engineering than the design itself.

[foozie]

Team 1124 had swerve drive in 2010. There was a front and back window motor steering with four independent drive motors. It supported swerve, traverse, car drive, and 90 degree swerve drive. It worked pretty well, as it won us Rockwell Innovation in Automation at Hartford and Hartford Regional.

[Hawiian Cadder]

team 159 had one around 2001, although it was not co-axial and it did catch fire during finals.

[PAR_WIG1350]

Originally Posted by Hawiian Cadder

team 159 had one around 2001, although it was not co-axial and it did catch fire during finals.

Flaming Unicorn Drive!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!

^that would make a good signature.

^ yes, I am aware that this wouldn't be true unicorn drive, but still.

[Racer26]

I believe 1334 had a Unicorn drive in 2010. It had 4 independently steered units, with independent speed control on a per wheel basis (IIRC).

1075 has only ever done 2+2 swerves, where the angular position of wheels is controlled in pairs. We did however invent DSSwerve.

[Ether]

Originally Posted by 1075guy

I believe 1334 had a Unicorn drive in 2010. It had 4 independently steered units, with independent speed control on a per wheel basis (IIRC).

Did it also have :

- unlimited rotation of the steering mechanism and the wheel angle sensor

- no "dead zones" in the wheel angle sensor

? if not, it was not Unicorn.

[Racer26]

I believe so.

[Al Skierkiewicz]

Now that you have reopened this discussion, I can enter what I forget to add before. Wildstang has always referred to this drive system as "crab" as that is the term camera dollies use. King Crab is a good choice for infinite rotation.

COTS Slip Rings are legal this year under <R40>.

[ratdude747]

2783 EOT made a "unicorn drive" in 2009.


it had 4 pods. each had 1 cim coaxially driven (by way of a thin gates belt) and next to the cim was a globe for steering (also connected by a gates belt). each pod had 2 rover wheels, for a total of 8 wheels. steering position was determined by 4 analog encoders. no dead zones.

by definition and posted examples, this might have been the first "unicorn drive"

not bad for a rookie bot?

i do not have much in the way of good pictures. I can get some good ones tomorrow (it is still used as a demo bot).

I do have a couple from the Mt. Washington FLL regional (tickets were raffled for chances to drive it). They are attached.

Upon my move to the team, i was shocked that they built it as rookies. I surely thought that it had been done by a veteran team earlier (coxiaxial 4 wheel independ. swerve), but according to this thread this may have been the first. go figure.

[Ether]

Originally Posted by ratdude747

2783 EOT made a "king crab" in 2009.

it had 4 pods. each had 1 cim coaxially driven (by way of a thin gates belt) and next to the cim was a globe for steering (also connected by a gates belt). each pod had 2 rover wheels, for a total of 8 wheels. steering position was determined by analog encoders

Was it programmed to be holonomic (all three degrees of freedom independently and simultaneously controllable) ?