The Perfect swerve

[Tyler2517]

I am looking in to design and manufacture the perfect swerve drive. What would be the best features if you had unlimited resources. Would you use field centric control robot centric or some type of hybrid? 2 speed shifters or a static gearing? What speeds? 4 wheel's or 3 wheel's? Do you care about the weight more then shifting? What wheel size? Any cool layouts that save weight or make it stronger?

Opinions are welcome.

[magnets]

hmm... an interesting question. Personally, I think that this is my favorite. It's really small, really light, and really cool. It's also nice because you don't have the drive axle after the supports on the module. Having the drive axle higher up than the module rotation bearing will really decrease the loads that part will see.

If you want two speed, I've seen a team 111/team 16 style swerve that has both the motor and the shifting mechanism in the rotating part. another cool idea would be to use a vex pro ball shifter, but then have the output shaft go directly into the module, so you're "direct driving" the swerve.

[EricH]

973's Emperor Swerve is the closest to a "Unicorn"-class swerve out there.

The "Unicorn" class, as I recall, is 2-speed, unlimited turning, non-coaxial (AKA, the motor is in the module), and each side (or is it each wheel) can be rotated independently of the other (minimum of 2 steering motors). It's not easy to do, but the benefits can be worth it.

OTOH, then there's 118's V6 designs...

[The Doctor]

Possibly a suspension like this: http://www.chiefdelphi.com/forums/sh...ad.php?t=92393

Our team also has some cool top-secret ideas on swerve, I must have speaks with my superiors.

[s_forbes]

Each module needs a CVT to transmit power to the drive wheel, and must not be limited by module rotation (similar to a coaxial module or a module with slip rings to power the motor).

Must be controlled by a plug directly into the driver's brain.

1717 has the best I've seen so far, and it improves every year. They do not have the restriction of unlimited resources, but do a good job of hiding it!

[craigboez]

Originally Posted by EricH

The "Unicorn" class, as I recall, is 2-speed, unlimited turning, non-coaxial (AKA, the motor is in the module), and each side (or is it each wheel) can be rotated independently of the other (minimum of 2 steering motors).

Technically, I don't think Unicorn drives can shift. The 973 implementation went above and beyond theoretical magical constraints.

[DampRobot]

Originally Posted by s_forbes

1717 has the best I've seen so far, and it improves every year. They do not have the restriction of unlimited resources, but do a good job of hiding it!

Quoted for truth. I hear they actually cut all their own gears, because it's cheaper and faster for them to make it out of round stock, in house than it is for them to buy and wait a few days for shipping.

I'd also check out 368's swerve, especially their driver setup. They played really well at SVR, and were the first swerve I've ever seen where the swerving actually improved their gameplay, rather than just being a cool way to move around the field.

[Gdeaver]

The perfect swerve for each team is the design that a team can implement in the build season constraints and with their resources.

[Ether]

Originally Posted by EricH

The "Unicorn" class, as I recall, is 2-speed, unlimited turning, non-coaxial (AKA, the motor is in the module), and each side (or is it each wheel) can be rotated independently of the other (minimum of 2 steering motors).

http://www.chiefdelphi.com/forums/sh...07&postcount=9

http://www.chiefdelphi.com/forums/sh...4&postcount=13

[JamesCH95]

The perfect swerve drive is the one that your team can design, build, and implement with the greatest degree of success. There is no magical gearing, wheel size, or control scheme that makes one swerve drive inherently better than another. There are several examples of very well-done swerves, but I'm sure each team who has done swerve drive can pick out something to improve.

Some witty comment about pursuing perfection and catching excellence instead...

[Zaque]

Originally Posted by Gdeaver

The perfect swerve for each team is the design that a team can implement in the build season constraints and with their resources.

Originally Posted by JamesCH95

The perfect swerve drive is the one that your team can design, build, and implement with the greatest degree of success.

Personally, I think you are missing the point of the thread. The hypothetical is with no limits on resources of any kind, so some designs are certainly going to be better than others.

[Conor Ryan]

Mechanically, a good swerve design is a good design. Teams that have gone through numerous iterations probably have it figured out better than most. Personally, I would love to see a 3 wheel swerve design with two cims driving each wheel, I'm not convinced the swerves we have seen so far are as fast as some of the tank bots. Additionally, I doubt a shifter gives much of an advantage to a swerve unless you are playing overdrive. 67 did an awesome 3 wheel swerve in 05, and I think that was the most dominant robot they have built to date.

I believe, the best swerve probably take their advantages from the controls that are engineered into the design. It goes above just having the right sensors, but having the correct algorithms to make driving intuitive and easy. Field oriented drive, with the ability to make the robot do what you want when you want is the hallmark of a well controlled swerve. Anyone have suggestions of teams that did this well? I know 16 and 111 did a lot of controls development to allow their drive teams to get the results they wanted, but I can't really comment on specifics.

I think we are just touching the tip of the iceberg with what can be done with the controls, the revised CAN system will really open up possibilities with finer control, and even make an auto shifting 2 speed shifter simple to implement.

[Tyler2517]

I think using a high end gaming mouse in the future to track the robot on the field will be something to watch out for in the future. I know i have been looking in to when it was mentioned in another thread.

[Dunngeon]

Originally Posted by Tyler2517

I think using a high end gaming mouse in the future to track the robot on the field will be something to watch out for in the future. I know i have been looking in to when it was mentioned in another thread.

If we attempt a swerve this offseason, this is going to be something we will try. It will be much more accurate for a field centric control scheme than what is currently being used (to my knowledge)

[Ether]

Originally Posted by Dunngeon

If we attempt a swerve this offseason, this is going to be something we will try. It will be much more accurate for a field centric control scheme than what is currently being used (to my knowledge)

Field-centric is about robot angular orientation. How are you planning to measure robot angular orientation with a single mouse? Won't you need two?