one control stick or two?

[Dave Flowerday]

Originally Posted by 346operator

I am the operator for team 346(the ones who scored 346 at VCU), and the new disussion with my team is whether we should go to one stick control. As the driver i feel that two sticks gives me greater control over the robot, however i havent spent much time on one so it is hard to say. Does anyone have input who has tried both methods?

When I was a driver for my high school team, I spent the first two years driving with dual stick control, and liked it a lot. My 3rd and final year, though, we had to switch to single stick control because we needed the other stick to manipulate our arms (this was pre-IFI controller days). Initially I wasn't very happy about the change and I thought that 2 stick gave me more flexibility. However, once I got used to single stick control, it was just as easy to use. In fact, I ended up greatly preferring single stick over dual stick.

Going from dual stick to single stick is an awkward transition at first, but it's pretty easy to get comfortable with it. Also, while dual stick may feel like it has greater control to some, I can't think of anything in particular that you can do with dual stick that you cannot duplicate with single stick.

[Marc P.]

I would guess it depends on the type of drive you use, speeds, straight tank drive vs. omni wheels, etc. I've driven primarily on dual stick on a 4 wheel tank drive, and prefer it in the sense that it gives you control of one side of the robot independently of the other. This can come in handy in a number of ways, especially when lining up for a precise task, or in a shoving match- it's nice to give more power to the side needing more force. The times I've downloaded the single stick drive for testing, I found the controls a little more intuitive, but I preferred having control over the individual drive sides.

[Pierson]

Our team leaves it up to the driver... Once we choose the driver they get to practice with both 1 stick and 2 sticks... they choose what they like better!

So... it should be up to whomever is driving and whomever is operating to choose what they want to use to be exact and precise.

[Tristan Lall]

188 has used 1-stick on most of the recent robots, with the exception of Blizzard 5. Why? My brother was driving that one.

Personally, I prefer the 1-stick drive, right-handed, and that's how I used it when I was driving Blizzard 4.

It isn't a difficult matter to program one or the other--so let the driver figure out what's suitable, because he's the one who's going to be using it.

[Blacknight]

I have to go with depending on the drivetrain.
Last year I drove an omni, and you need two, just for calibration problems, but I prefer one stick for tank drives. Not a big fan of two sticks other than for omni...

[jonathan lall]

Your team should really leave it up to your driver. There's code available online for both of these, so it certainly isn't a problem from a programming point of view. If your robot pulls to one side (this is prevalent in tank-drive robots with two identical gearboxes, wherein one side has motors driving in reverse and thus runs slightly slower), you might want to go one-stick, because straight lines are much easier to hold. However, you will find that cornering is a dream on two sticks and you can fluidly move around obstacles without slowing down. Two-stick is also quite a bit harder to truly understand so practice is very necessary. While it's certainly less intuitive, you should make the call early on whether it's worth it to learn two-stick properly, or if you should just do one-stick, which, as was mentioned before can technically do all or almost all a two-stick control can do. It really is your call, and neither is superior. Though two-stick is better.

I have driven both configurations, and while my recent predecessors opted for one-stick, I went to two this year. One of the main advantages of two-stick is its excellent conduciveness to turns (in tank drive). In a one-stick configuration, one must apply forward motion with the y-axis, while also concentrating on slowly and nonlinearly moving the joystick sideways along the x-axis. This results inevitably in jerky turns on occasion, especially very sharp ones (two years ago limbo bar to ramp comes to mind), no matter how good the driver is. Of course, there's a lot less thinking involved when driving one-stick by nature, so open space driving means you can just will the robot to a spot on the field.

Enter two-stick: it's much harder to control a jumpy or fast robot, but when going left around a corner for example, if you tap the left stick slightly back of centre (to apply some reverse current locking the left wheels) and at the same time throw some forward power into the right wheels, a very smooth, fast turn can be made. And just like driving a car, as you hit the apex, you can apply more and more juice to come out of the turn. You'll find you're rounding corners very fast.

I need not remind everyone that your control system should adapt to the game and function of the robot. The best advice I can give is let your driver tell the programmers what he or she wants, because if the driver's not happy, the robot won't drive well.

[Lisa Perez]

In addition to what everyone has said thus far, with two-stick it is somewhat simpler to adjust to problems with the drive (for example, one side may not be performing at the same speed as the other for whatever reason). Adjusting with one-stick is doable, but personally I believe it is much harder.

[Tytus Gerrish]

for a tank drive type system In my opinion 2 Stick is deffenetly better.

[Billfred]

I'm inclined to agree. 1293 had one stick this year for driving, and BOY was it a pain in the wazoo to get that joystick to center! We couldn't get the darn thing still in both axes for quite a while, then had to remember which joystick was which when we plugged it up, since our arm controller was calibrated differently.

Your mileage, however, may vary.

<edit>I should point out that 1293's setup was the classis skid-steer setup, with shopping cart-ish casters on the other wheels.</edit>

[Josh Hambright]

I would have to say that it does depend on what type of drive your using.
When i was a driver/operator for 461, I used a few different configurations for driving. When we had our hybrid/omni/crab drive we used 1 stick and a throttle. I liked that alot although i also liked driving that one without the throttle. When driving a tank style drive base though i cant say enough about the controllabilty of using 2 sticks, in my mind it really give you the most accurate and effective control over your robot.

[Kyle Love]

On 45, we used 2 to drive 2 to operate. Our engineers talked to the drive team, from what I heard and figured out the easiest way to control it. If you have ever seen our arm I don't think theres a way to use just one stick. HAHA! If you want to see a pic of the arm go here.

-Kyle

[Jay H 237]

Originally Posted by jonathan lall

If your robot pulls to one side (this is prevalent in tank-drive robots with two identical gearboxes, wherein one side has motors driving in reverse and thus runs slightly slower)

Team 237 has basically relied on a tank style drive and two joysticks since the begining. We did have it switchable one year between two or one stick but found 99% of the time the drivers used two sticks. I'm not going to say one is better than the other because as everyone else pointed out it depends on the driver(s) and the design of the robot. What I do want to mention is what Jonathan mentioned and I quoted. We had the same issue where the robot would "drift" because of the motors running in opposite directions. What we did is install a "jack shaft" on one side between the motor and the gearbox. What this did is allow both motors to run in the same direction and thus the same speed.

[jonathan lall]

Originally Posted by Jay H 237

Team 237 has basically relied on a tank style drive and two joysticks since the begining. We did have it switchable one year between two or one stick but found 99% of the time the drivers used two sticks. I'm not going to say one is better than the other because as everyone else pointed out it depends on the driver(s) and the design of the robot. What I do want to mention is what Jonathan mentioned and I quoted. We had the same issue where the robot would "drift" because of the motors running in opposite directions. What we did is install a "jack shaft" on one side between the motor and the gearbox. What this did is allow both motors to run in the same direction and thus the same speed.

That stick control toggle thing is what I wanted last year. That, IMO is the perfect tank drive system. As for the motors running in the same direction, usually what's done to remedy this is having a change gear of the same size and pitch as the last gear, which it mates to on the end of the problem gearbox, thus reversing the direction of rotation and equalizing speed.

[Stephen Kowski]

i would imagine that you could splice in the cable for the second joystick so that you would only be using one port (so then it just comes down to the driver's preference and nothing else).....there are a lot of available inputs....haven't ever tried it, but I smell a project coming on....

[Ryan M.]

Originally Posted by Stephen Kowski

i would imagine that you could splice in the cable for the second joystick so that you would only be using one port (so then it just comes down to the driver's preference and nothing else).....there are a lot of available inputs....haven't ever tried it, but I smell a project coming on....

Yes, you can splice it. Our team did it. We went with two joysticks, spliced the x of one into the y of the other. Of course, this means you only read front and back position. Worked fine. If you have constants pointing to it, it doesn't even make programming harder...