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Unread 27-10-2012, 17:39
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Nuttyman54 Nuttyman54 is offline
Mentor, Tactician
AKA: Evan "Numbers" Morrison
FRC #5803 (Apex Robotics) and FRC #0971 (Spartan Robotics)
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Re: [EWCP] Skid Steer Drive Optimization

Quote:
Originally Posted by MattC9 View Post
For some one who dose not live on the west coast, can some one explain how cheesy drive is different from arcade or tank?
First off, my descriptions of these control methods only apply to skid-steer drivetrains like 4wd/6wd/8wd etc. Other drivetrains may call their control method Tank or Arcade, but the control is implemented differently. Skid-steer drivetrains work by using a speed differential between the left and right wheels to cause the robot to turn.

A brief summary:

Tank - 2 joysticks, each being used like a throttle for a drive side. Left stick controls the speed of the left side, right stick controls the speed of the right side. The x-axis on the joysticks are not usually used for anything.

Arcade - 1 joystick, the y axis controls the average speed of the driveline, and the x axis adds/subtracts a constant value from each side to create a differential speed, causing the robot to turn. This is not

"Cheesy Drive" - Usually implemented with a steering wheel, but can also be done with a single joystick. It works like a more advanced version of "Arcade" drive, where the steering wheel/x axis controls the turning radius (like a car), and the y axis controls the throttle/speed. This is a very important distinction, especially for high-speed drivetrains. It lets the driver control turn radius and speed, rather than turn rate and speed. At high speeds, a small change in turn rate results in a very fast change in robot heading, and with an Arcade setup, changing the throttle setting alone will change the turn rate. With "Cheesy Drive", as long as the steering wheel position is held the same, the robot turn rate remains the same, regardless of the throttle setting. The steering wheel is not necessary, but it provides a familiar control input, since the radius/speed control is exactly what you get with a car.

A lot of top teams us some implementation of "Cheesy Drive", including 254 (of course) and 971. I believe 111 and 973 both used it in 2011, meaning the entire winning alliance was using it in some form.
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Last edited by Nuttyman54 : 27-10-2012 at 17:42.
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