Wheel controller for FRC

I know that some teams use a Wheel Controller to drive their robot.
what is the advantages and the disadvantages of this control system?
If some one ever use it, can you tall me what you know about this control system and why teams like 971 and 1678 prefer to use this control system?

Thank You!

I think it’s just preference of the driver, like if someone were to like an Xbox controller over the standard joysticks

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In theory, it’s more intuitive and the larger wheel allows for more precision. In practice, driver preference is king.

A racing wheel controller really only works if you have the right drivetrain. I could see a modified wheel set up to be continuous working for in place turns on a swerve drive. It also works well if you have a drivetrain with 1 swerve wheel and 2 regular driven wheels. (Or, “Swartdrive” as I like to call it.) I can’t really see a wheel controller working for a traditional drop drive, unless your driver was quick enough with it for the fast turns usually needed in FRC.

It is definitely a preference of the driver. I can never drive with a Wheel or a flight stick. The Wheel is simply too bulky, requires too much hand motion, and does offer nearly the same amount of buttons/controls that I like to use. A flight stick, again, requires too much hand motion and also has limited buttons on the stick itself.

IMO xbox controller is the way to go, the thumbsticks and triggers offer more precision than you will even need, and the number of buttons available at your fingertips is great. But you have to use what best suits you. Don’t think “oh let me use a steering wheel because 971 does”. Your own preference is key.

We drove at Madtown this past week with a wheel and joystick setup (on a swerve drive, if you would believe it!) And we found it to result in far more intuitive, precise, and quicker driving than an Xbox controller.

How did you map the controls with the wheel and joystick for swerve? The only way I could think of is to have the joystick control change in field-centric position (Δx and Δy) and the steering wheel control change in rotation (Δr). If you have an infinite rotation steering wheel I could imagine the steering wheel controlling absolute position (r relative to the field). To me, neither of these seem more intuitive than an xbox controller. Is this how you set it up, or did you come up with a better way?

The joystick controlled robot-centric translation, and the wheel controlled either rotation in place, or rotation while driving as an arc (snake mode, car mode, or any of the other names people have called it)

I have to strongly disagree with this. With properly set up drive code you can achieve an incredibly nimble, highly accurate drop center drive system with a wheel and joystick combination.
That said, it truly depends on the driver’s preference. The best advice I can give is, get your driver’s input, then tune the drive well. Finally, practice, practice, practice.

Everyone is talking about how a steering wheel gives you super highly accurate precision movement. I only want to point out that, this is FRC, we aren’t picking up 1 inch diameter objects, with a tiny 1inch claw. You don’t need insane precision. And besides, if properly used right an Xbox controller gives you the exact same amount of precision.

But the final decision should be your driver’s. And whatever he/she chooses, they definitely need to practice a lot with it. (I personally practice a lot with my Xbox controller by playing a ton of rocket league :smiley: :smiley: :smiley: ).

When you are coming across the field at 10 feet per second and need to rotate within a foot margin of error to cross a defense, the precision comes into play a lot. Small control inputs can make a big difference in this situation. If an input of 0.4 turns it enough to make it over the defense but 0.3 doesn’t, then that is going to about an inch of movement on a wheel compared to a couple of millimeters on an Xbox stick. For teams like 1678 and 971, the few seconds gained will be very important. For the rest of us, maybe not. But there is definitely a positive in that respect to the wheel.

Having driven a robot this year with a top speed of 25 fps, and using a xbox one elite controller. I can personally vouch for the fact that you can indeed get the same precision required to go over defenses on an Xbox controller without stopping, with the proper practice and natural skill.

If you don’t mind me asking, what kind of gear ratio and weight did you have that let you achieve 25 fps during match play?

We almost never hit 25 fps within a match, purely because of the acceleration time required. Still we were definitely one of the fastest bots on the field at the regionals we went to.

The bot weighed (without bumpers and battery) around 90 lbs. We had a 3 cim, 2 speed ball shifter. I don’t know the ratios, I can find out in a week (after thanksgiving break) if you really want.

Just a question - have you ever personally tried a wheel, joystick, etc. for robot control? If not, I would encourage you to pass judgement and not dislike something so strongly without using it first.

From what I have seen of your video, you guys do a lot of stop and go kind of movement. I’m talking about fluid arcs, which would on the surface appear to be easier with a wheel setup. Also, saying that your robot achieves 25 fps misrepresents reality, and I wouldn’t want a rookie to see this and think that that is a realistic speed, build a robot around it, and then watch their robot not be able to move once it is weighted down.

First of all, yes I have attempted to use my logitech g920 when I was first evaluating my driving options. And second, notice how I never said the a steering wheel sucks. All I said was that I can vouch for an xbox controller to have the same precision. And I will repeat myself again, the best option to use is the one that the driver likes. All I’m warning against is falling into the trap of “this elite team driver is using this method, so I must also use that method”. I myself have fallen into that trap… many times.