Steering wheel
 

Our team is looking for a steering wheel to use for next year. We already took apart two old wheels for N64, only to find that they used some sort of optical encoder instead of a potentiometer.

For you teams with a steering wheel controller, what kind of wheel did you use? Or did you use some sort of clever hack, like mounting a potentiometer to the wheel? (we tried that, too)

Re: Steering wheel
 

I know 968 drove with a steering wheel last year. Maybe you can find out how they did it.

It is also possible to de-serialize a PS2 controller output into the OI, so that could be a possibility. Also, a company called Cross the Road Electronics is selling a device that will let you plug a USB HID Compatible wheel into the OI.

Re: Steering wheel
 

67 used a steering wheel in 2005.
I can't remember the exact name of it, but it was a fairly cheap one for the playstation 2. It was blue, grey, and black. And if my memory serves me correct, it had a potentiometer that we just soldered leads to.

Re: Steering wheel
 

what you should do before you take the leap and spend the money is see if you can get another team which uses one, to loan it to you to try out. You may very well not like it.

Personally I've always driven with sticks, and I liked sticks because I had the benefit of tank drive, and individual side control.

But to each his own. :)

Try before you buy.

Re: Steering wheel
 

IMO I feel you'll wish you had sticks for independent control of each side a stick offers.

Re: Steering wheel
 

One of our team members donated an old wheel to us last year and it has worked wonderfully. It came with a potentiometer. After a short search on Ebay, it looks to be a Mad Catz MC2 Xbox Steering Wheel. Beware that the buttons on the wheel are analog buttons, but I wired them just like potentiometers and they have worked wonderfully.

Austin Schuh

Re: Steering wheel
 

I checked ebay, and the wheel that 67 used in 2005 was a MC2 MicroCon Racing Wheel for the PlayStation 2. They are pretty cheap and nearly ready, you only have to solder leads to the included potentiometer.

Re: Steering wheel
 

If programmed correctly a wheel can give you all the same control options as joysticks, It will just feel different.

Re: Steering wheel
 

I'm not exactly sure about using a steering wheel... the quick maneuvering changes one has to make when in a pushing match would be tough to pull off with the wheel. If youre using a wheel/caster or skid steer system, or any other system that has motor(s) on each side, I really would suggest just having a joystick for each.

The steering wheel would work if for some reason you chose to put turning wheels on the front of the robot, but like i say i'm just wondering if you can maneuver quickly enough with the wheel. I'm not questioning if you can do it, just the rate at which the driver can correct the path/power output of the robot might be a little sluggish. Anyhow, just my two bits.

-Q

Re: Steering wheel
 

I call shenanigans. The robot can be just as quick on its wheels with a steering wheel as it can with one or two joysticks--in each case, the OI is just reading potentiometers and sending the data to the RC to interpret. The challenge in any driver-OI setup is to make sure the driver can reliably and easily command the robot to do what he or she wants. If your driver thinks a wheel is the best way to go about it, go for it. If they want sticks, go for it. But I believe both are like the wheels-versus-treads debate: go with what works for you.

Re: Steering wheel
 

If you think this is the case, clearly you've not seen the many extremely manueverable robots that use wheels. It's all about the implementation.

Re: Steering wheel
 

Hey Cory, might just be me, but I'm thinking that most of the maneuverable robots use wheels, they help you roll across the carpet a lot easier. ;)

btw - give you one guess as to where 668 got the idea to go to a steering wheel.:)

Re: Steering wheel
 

Team 1403 began using the steering wheel after Atlanta and we are very happy with the outcome. We are able to maneuver very quickly with the wheel, and we are able to make more precise movements with the wheel. I noticed teams like 254, whose driver is so quick with the steering wheel, dazzle us with their driving skills. I have also seen many teams who use joysticks who can do the same thing. But like some have already mentioned, it really comes down to what the driver is comfortable with on the field.


I will try to find the brand of steering wheel that we use. It turns out that the steering wheel we have already has a serial port. After a little bit of tweaking, we were able to make the wheel function exactly how we wanted it to.

Re: Steering wheel
 

I'm glad this topic was posted. Although I really think that joysticks are the way to go, my students this year feel very stongly about using a steering wheel. Although we haven't purchased anything yet (we'll wait for kickoff in case there is a change in the OI), we have started discussions of how to program the thing. It does pose some intersting challenges for the programmers.

As far as manuverability, I think that joysticks give more options while turning (tight turn radius/0 turn radius and so on). On the other hand, if the driver never makes use of all of the options available and can effectively drive using the steering wheel, then by all means go for it.

Re: Steering wheel
 

As Cory stated, you can do all these things and more with a steering wheel. It's all about the implementation.

Re: Steering wheel
 

The robot has the same options for turning no matter what you go with--all you're changing is how you tell the robot to do it.

Assume you have one joystick for throttle forwards and backwards, then one steering wheel to determine rate of rotation. Calculate the difference in PWM values needed given the position of the wheel, then add in the throttle values. Since this might throw the PWM values out of the valid range, add in some code to scale back the numbers until neither is over 254 (or below zero).

IANAP (I Am Not A Programmer), but this would be how I'd attack the problem for a basic drive system without feedback or anything--those folks who actually know what they're talking about can elaborate there.

Re: Steering wheel
 

True. My initial impressions (while I was writting before) was that with the steering wheel it was more of an either/or proposition--I can either have a tight turn (ex. left wheels = 127, right wheels = 254) or 0 turn radius (left wheels = 0, right wheels = 254), but not both as would be possible with joysticks.

Further thought on the matter has led me to an implimentation that would allow both--I guess I just like joysticks because with a rookie team that only has 1 programmer (and she has no previous programming experience), I'll probably end up writting most of the code this year and joysticks are easy to implement.

Re: Steering wheel
 

DISCLAIMER: I have never tried this
I think if you used the one joystick drive setup in the default code and just used the steering wheel's output instead of 'p1_x' and used the throttle joystick's y value in the place of 'p1_y' it would work.

Re: Steering wheel
 

You could always have a button on the steering wheel or a switch to change drive modes.

Re: Steering wheel
 

Now that I think about it, this is exactly what the one-joystick code does. BRILLIANT!

Re: Steering wheel
 

K.I.S.S.

Now that I'm done beating my head against the desk for not recognizing the obvious I guess I can spend my time on more exciting things (like unpacking the huge order of supplies from McMaster-Carr and OnlineMetals--it really is Christmas time!).


That was the conclussion I came to after thinking about the problem a little more.

So now, as long as the steering wheel and the throttle either self-center or have a sufficient deadband built in to the code, I'm beginning to think this could be a very effective control that I had simply dismissed previously.

Who said you can't teach an old dog new tricks? :)

Re: Steering wheel
 

For those who feel that the wheel will not give the same control options, I would have to say you are thinking too much inside the Joystick. The wheel can give you differences in control from only one or two pwm to 0 on one side and 254 on the other. Therefore any combination in between is possible with some rotation of the wheel.

Re: Steering wheel
 

I am not a programmer. I understand the basics behind what we did, and the principle, but not much else.

Our wheel acts exactly as a joystick would. If we turn the wheel a tiny bit, the robot turns a tiny bit. It's exactly the same as if you pushed one joystick forward a tiny bit and one backwards a tiny bit. It's scaled this way throughout the travel of the wheel. Our driver vastly prefers driving the robot this way, and after 3 years he's gotten pretty darn good at it.

The wheel we use is the NASCAR Charger 2 by Thrustmaster.

Re: Steering wheel
 

What are you connecting the serial port to? There isn't anything on the OI that can deal with a serial output from a controller device.

Re: Steering wheel
 

Yep. You are right. I meant it already had the 15 pin analog interface already. It was something we specifically looked for in a steering wheel before we bought one. It plugged right in with no changes necessary. We bought a discontinued wheel off of Ebay. I still haven't gotten the chance to check the brand yet though.

Re: Steering wheel
 

Further supporting the wheel ..

Think of the range of motion you have with a joy stick. 90 degrees, at best. With a steering wheel, you have over 200 degrees of control (if not more, depending on your wheel). This was the argument supporting the wheel presented to us by a mentor from Team 60 (after 60/254's extremely successful 2004 season).

It is MUCH easier for students to learn how to drive the wheel than with (a) stick(s). And that's not limited to students, if you have a sponser, little kid, future team member, etc .. driving, it's much easier for them to get a feel of it without crashing into something or someone.

With that said, 1388 has used a wheel in 2005 and 2006. In fact, we already have our wheel for 2007. It's a Saitek R80, and we've got all 3 of ours new off ebay for less than $15 each. There are plenty of USB wheels out there, and if you have a rich team that wants a pretty wheel, then consider the new IFI USB dongle for the OI.

There is some fine tuning on the driving code needed for the wheel. There is also a lot of room for improvement. We have added features into our wheel code that allows for much easier turning (pretty much turning in place). There is also a switch on our 2006 control box, that lets you jump from a wheel/joystick combination to a single stick for driving.

Re: Steering wheel
 

After trying a steering wheel for the first time this year I'd have to agree...

Having the steering wheel and one joystick for throttle made it much easier to turn, turn inside our footprint and drive straight (encoders of course helped out too).

We had a first year driver and it only took him a couple minutes to get the hang of driving around with the steering wheel. After about a day on our practice robot he started looking like natural on the wheel.

Re: Steering wheel
 

I don't know if anyone has realized it but using a steering wheel and throttle setup is the same thing as using one joystick......

steering wheel = left/right movement of joystick
throttle = front/back movement of joystick

-John

Re: Steering wheel
 

maybe this is too obvious...but how about an r/c car controller? it has a steering wheel and throttle control, and driving an r/c car with one is very easy.

http://www2.towerhobbies.com/cgi-bin...I=LXPNM9**&P=7

for example

Re: Steering wheel
 

For the most part it is, but from the teams I've talked to that run wheels (including ours), there are some "features" added to make driving easier (turning harder at certain positions of the wheel, jog L/R, shifting ease, etc). Main advantage of the wheel, you have a much larger range of motion to adjust your control.

This is a summer project I've wanted to do for awhile, but have never got around to doing it - using a mini EDU controller and the r/c car controller to try and drive the robot. Sadly, I don't have the programming background to set the EDU up to do it. It would be really cool to be able to eliminate the full sized RC and OI for doing demonstrations and stuff where the full control system isn't needed.

Re: Steering wheel
 

If you need to just use the drive base all you need is a vex kit with the default code on it. just hook it up with a Y-cable or so that you control one side with 1 PWM channel. I have hook the VEX stuff up to victors and it works perfectly, there is no reason why it wouldn't. If you need more help PM me.

-John