Cheesy Poofs are the Real Deal...

[Jay Lundy]

Originally Posted by eugenebrooks

Would you be willing to describe how the (throttle+wheel) control system programmed?

No problem.

Basically, when you turn the wheel to the left and push the throttle forward, the right side moves at whatever speed the throttle is at, and the left side is reduced by a percentage equal to the turn percent of the wheel. So if the wheel is turned all the way to the left, the reduction is 100% and the right moves at throttle and the left moves at 0 (really 127 + throttle and 127).

When the wheel is to the right the same thing happens except the right side is reduced and the left side runs at throttle.

At lower speeds, the side that is being slowed down actually goes below 127 to make a tighter turn. The output to the left motors changes linearly from 127 + throttle (wheel = center) to 127 - FAST_TURN_CON (wheel = far left) while the right stays at 127 + throttle.

When the wheel is in the center dead zone, the robot enters straight drive mode, which uses prox sensors to keep the robot driving straight (it curves due to the drill motors).

There are also paddles on the wheel which we use to turn in place. When a paddle is pressed, it powers the 2 sides in opposite directions at a speed equal to the distance of the wheel from center.

Being the base driver and one of the programmers, I've had a lot of experience with the steering wheel. I have to say it is a life saver for our robot. The robot is a 6 wheel drive with the center wheel slightly lower than the others and it is uncontrollable with the normal 2 stick tank drive. It drives way too fast and turns way too easily. It took a lot of getting used to, but now I can drive it as well as I could with 2 sticks.

If your robot drives fine with 2 sticks or 1 stick, I'd stay with that. But if you find that it turns too easily and is uncontrollable, a steering wheel is definately the way to go.

Alex beat me to it, but I'll still leave my post...