Driving: Tank, Arcade or FPS?

[RunawayEngineer]

My personal favorite way to drive a tank drivetrain is to use 2 single axis joysticks for tank drive control scheme. The removal of the degrees of freedom of the joysticks allows you way better feedback and control. This is because if you are off straight on a double-axis joystick, your hands will feel a different travel distance than the controls are being sent.

[JamesCH95]

Originally Posted by RunawayEngineer

My personal favorite way to drive a tank drivetrain is to use 2 single axis joysticks for tank drive control scheme. The removal of the degrees of freedom of the joysticks allows you way better feedback and control. This is because if you are off straight on a double-axis joystick, your hands will feel a different travel distance than the controls are being sent.

While that may be in improvement over two 2-axis joysticks, it still doesn't deal with the difference in dexterity between the driver's two hands. They will almost always have better dexterity with one hand than the other, and a single joystick will allow them to put that dexterity to use, instead of being dragged down by their less-dominant hand's performance.

Two-stick tank drive is like drawing with an etch-a-sketch and single-stick arcade is like drawing with a pencil; yeah, the etch-a-sketch can sometimes make a good approximation of a pencil drawing, but it's never going to be quite as good.

[RunawayEngineer]

Originally Posted by JamesCH95

While that may be in improvement over two 2-axis joysticks, it still doesn't deal with the difference in dexterity between the driver's two hands. They will almost always have better dexterity with one hand than the other, and a single joystick will allow them to put that dexterity to use, instead of being dragged down by their less-dominant hand's performance.

Two-stick tank drive is like drawing with an etch-a-sketch and single-stick arcade is like drawing with a pencil; yeah, the etch-a-sketch can sometimes make a good approximation of a pencil drawing, but it's never going to be quite as good.

The dominant hand effect might be there, but I don't think that it is significant. First of all, I never noticed it in my years on a drive team.
But less anecdotally . . . look at guitar-playing: the non-dominant hand is doing at least equal dexterity tasks, probably moreso. Practice and muscle memory can remove that weakness from that activity.

[JamesCH95]

Originally Posted by JABot67

RC Car Drive:
Left thumb Y axis gets mapped to ArcadeDrive forward-backward
Right thumb X axis gets mapped to ArcadeDrive turning

[IMG]http://juguetedivertido.com/wp-content/uploads/2011/02/YY-4582Remote.jpg[IMG]

This drive control scheme is the only scheme that has been used by any of the teams I have been on, from 2007 to 2015. It gives the driver an absolutely guaranteed way of driving straight forward and back, and no other drive scheme mentioned here comes close. It also allows the driver to turn on a dime, with no forward-to-backward movement if none is required - useful when you don't have that much room.

One thing my team noticed in 2012 was that teams who used two-stick tank or one-stick arcade drive were struggling to balance the bridge. Thinking about it, it makes sense - when you are trying to drive slowly forward or backward with one of those drives, you may end up inadvertently turning.

This thread really should be a poll - I think RC car drive is actually a very popular drive (and is also by far my favorite! )

With mecanum and slide and swerve drive, different drive schemes have to be used. I would probably recommend the First-Person Shooter drive, using the free axis of the forward-backward stick to strafe.

It doesn't seem like you read the thread... what you call "RC car drive" is what is commonly know as "FPS" control. Other control methods, including single-stick arcade (with a gimbal stick), provide a reliable way to 'drive straight forward.'

Frankly, even FPS style control won't be guaranteed to drive perfectly straight without closed-loop control due to variances in motor torque and drivetrain drag. And when closed-loop control is in the mix, almost anything can manage to reliably drive straight.

It is a horrific and sweeping generalization to say that: "teams who used two-stick tank or one-stick arcade drive were struggling to balance the bridge." Your conclusion that their control system was holding them back is simply false.

Now, I'm not saying "FPS" drive is bad, it certainly is a great drive control scheme, but don't undercut your own argument by making such rash statements.

Originally Posted by RunawayEngineer

The dominant hand effect might be there, but I don't think that it is significant. First of all, I never noticed it in my years on a drive team.
But less anecdotally . . . look at guitar-playing: the non-dominant hand is doing at least equal dexterity tasks, probably moreso. Practice and muscle memory can remove that weakness from that activity.

Sure, lots of practice always helps. Perhaps that is not the best anti-two-stick-tank argument.

Still, how can a two-stick system drive straight at part-throttle? This is VERY difficult to do.

Consider this thread from last year: http://www.chiefdelphi.com/forums/sh...d.php?t=125759

Team 33 found that all drivers wound up preferring FPS-style control to two-stick tank and found it "way easier" to control their robot(s).

[JABot67]

Originally Posted by JamesCH95

It doesn't seem like you read the thread... what you call "RC car drive" is what is commonly know as "FPS" control. Other control methods, including single-stick arcade (with a gimbal stick), provide a reliable way to 'drive straight forward.'

Frankly, even FPS style control won't be guaranteed to drive perfectly straight without closed-loop control due to variances in motor torque and drivetrain drag. And when closed-loop control is in the mix, almost anything can manage to reliably drive straight.

It is a horrific and sweeping generalization to say that: "teams who used two-stick tank or one-stick arcade drive were struggling to balance the bridge." Your conclusion that their control system was holding them back is simply false.

Now, I'm not saying "FPS" drive is bad, it certainly is a great drive control scheme, but don't undercut your own argument by making such rash statements.

This drive is called "First-Person Shooter Drive" by the first poster in this thread, then called "Split Arcade Drive", "Kaj Drive", and "RC Car Drive" during this thread. I don't think it has a universal name, but you are right that I should not have presented the name I use as the correct name.

Regarding "FPS Drive", I think the name is actually good for describing a drive that allows strafing - many FPSes (Halo, etc.) allow you to strafe using the left joystick (same one for going forward and backward).

"RC Car Drive" could also be considered a bad name for the control scheme, because real RC cars are not tank drive and can't turn on a dime.

Regarding the rest of your post, I am glad we agree that it is very important to have a foolproof way of going straight forward and backward. I am very curious about everyone's opinion about what drive control schemes perform the best, or if it matters at all. I think that your chosen scheme does impact your performance, but not as much as driver skill and practice.

And yes, one of my statements up there could be considered a "horrific and sweeping generalization". I was considering removing it, but I'll leave it there for now. This was my first controversial post on CD!!

[DarkRune]

Running octocanum this year, and because of the driver (I don't know why, he just likes it and it seems to work well) the traction wheels will be controlled via tank, however the mecanum drive will be a sort of split arcade where one joystick is f/b/l/r and one joystick is purely turning. Kind of a weird setup, but he likes it and it seems to work.

[artdutra04]

I used to prefer 2-joystick tank drive to regular arcade, but after trying split-arcade, it's my new favorite. Very intuitive, especially for anyone who has played video games.

IMHO the terms "split-arcade" and "FPS" control modes are not interchangeable terms for the same thing.

Split-arcade is for skid-steer robots, as it cannot handle strafing of any kind. FPS can only be used on swerve/mecanum/holonomic robots where the left joystick is full X-Y translation and the right joystick is rotation.

[Ether]

Question for those teams using XY on one Joystick and rotation on the other: do you use the left or the right joystick for XY?

[zinthorne]

Originally Posted by Ether

Question for those teams using XY on one Joystick and rotation on the other: do you use the left or the right joystick for XY?

In most video games with an xbox controller the left stick controls turning and direction and the right controls your view. (Like which way you are looking)

I am a big forza fan and other fps games. Forza drives with the triggers controlling forward and brake and reverse. Left is reverse/break, and right is forward. The left joystick controls turning and the right stick is generally not used much, because if you are doing manual transmission you must use x and b for shifting. In Halo it is pretty much the same with the right stick being used to control where u look.

I personally am going to drive with an xbox controller if the proggramers will let me. (We have no previous experience with one) I would like to merge both forza and halo and us the two triggers to drive and control speed. (Forward and reverse are only on the triggers) and then use the left stick for turning. Then the right joystick would be used to control all driving. (Forward, backwards, turn left, turn right) When used though the robot would only run at 25-50% speed, while all other drive controls are then not used during that time. The low speed would allow for fine movements without worry of over correcting or accelerating too fast when you are in a crammed place.

[Gregor]

Originally Posted by Ether

Question for those teams using XY on one Joystick and rotation on the other: do you use the left or the right joystick for XY?

XY is on the left joystick, turning on the right.

[DarkRune]

Originally Posted by Ether

Question for those teams using XY on one Joystick and rotation on the other: do you use the left or the right joystick for XY?

XY on the left joystick, turning Z on the right joystick.

Originally Posted by JamesCH95

I think that 33's experience (documented in a thread I linked earlier) is basically a microcosm of all of FRC's experience with two-stick drive. A lot of drivers think that it's intuitive at first, so they ask for it without knowing any better. However, once they get used to 'split arcade' or 'fps' or some other more sophisticated control scheme (where the computer is doing the drive control math instead of the driver, where drive transforms can be used) they wind up preferring it to two-stick. I believe this is why teams rarely, if ever, change back.

This is my personal experience, but after switching to arcade and split arcade, I was really unsatisfied since it seemed at least to me to be more work and math (though it probably isn't), whereas tank (for me) seemed to be completely intuitive and required no mental math. The problem I had with split arcade was how turning was completely independent of of the other drive joystick. So I tried out arcade and I liked it a little, but there was more of a thought process for what angle to press the joystick at, how much to turn, etc. With tank this doesn't require any thinking.

[Zebra_Fact_Man]

Originally Posted by Ether

Question for those teams using XY on one Joystick and rotation on the other: do you use the left or the right joystick for XY?

I come from the old-school School of Tank Drive: Left Joystick is left, Right Joystick is right, but I just recently switched teams, and my new team is trying out the FPS style controls for the first time.

We are going with H-Drive this year, so our controls are as follows:
Left Thumbstick = forward, back, strafe L/R
Right Thumbstick: Left = turn left, Right = turn right
Directional buttons = precise directional movements (50% speed of Left Thumbstick)

This is an entirely different world than what I'm accustomed to (back when I drove a long time ago, using joysticks instead of videogame controllers), but the kids seem to work well with it, so that's all that matters to me.

[RunawayEngineer]

Originally Posted by JamesCH95

Sure, lots of practice always helps. Perhaps that is not the best anti-two-stick-tank argument.

Still, how can a two-stick system drive straight at part-throttle? This is VERY difficult to do.

Consider this thread from last year: http://www.chiefdelphi.com/forums/sh...d.php?t=125759

Team 33 found that all drivers wound up preferring FPS-style control to two-stick tank and found it "way easier" to control their robot(s).

Well, I was a base driver in 2008 - so if you are familiar with the game, then you know that driving at less than full throttle was not a scenario that I encountered
I have no question that 2-stick tank requires finesse; but from running driver training with RC controls, I know that that is not a unique situation.
If people find something that they like, more power to them. I haven't discounted any method of control.

[JamesCH95]

Originally Posted by RunawayEngineer

Well, I was a base driver in 2008 - so if you are familiar with the game, then you know that driving at less than full throttle was not a scenario that I encountered
I have no question that 2-stick tank requires finesse; but from running driver training with RC controls, I know that that is not a unique situation.
If people find something that they like, more power to them. I haven't discounted any method of control.

Have you found a story of any team that switched to two-stick tank from any other method of control? I can only find threads like this, where teams ditched two-stick tank for another method they found to be superior.

[cadandcookies]

Here was 2220's progression (with skid steer robots):

2012: Joystick tank drive
2013: Controller-based tank drive
2014: Controller - based FPS drive

Whatever paradigm of control you use (tank, arcade, FPS), for a lot of kids (at least in my experience), a controller is most intuitive. And FPS is almost always most intuitive from a controller. At least in my experience/opinion. Personally I'd shy away from telling the driver how they'll be controlling the robot