Quote:
Originally Posted by Doug Leppard
Our drivers are happy with our traction control. We have the driven wheel encoder and a vex Omni wheel on the floor called the undriven wheel.
We found 20% slippage is the best. Our moving algorithm follows the joystick either increasing power or decreasing power according to the joystick position and wheel slippage.
But you have the 0 or little speed situation, for instance you may be in a pushing war and going almost 0.
For that we don’t do a ratio of slippage because it does not make sense. But we allow a certain number of rpms of the wheel which is slippage at a standstill.
It is very simple.
BTW we put a toggle switch on the driver’s station that allows the drivers to turn off and on the traction control; sometimes the drivers use the large amount of slippage to their advantage especially in turning.
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Doug,
In order of implementing a traction control algorithm I have proposed for a FRC conference presentation paper with VEX and Easy-C Pro implementation: 1) rate-limiting joystick command input to motor command output - solves a multitude of problems, 2) control maximum motor speed command as a function of undriven wheel speed (non-feedback based slip control) Joystick position can be independent of the maximum motor speed command but you have indicated that you did
add joystick dependence. Can you indicate why? 3) feedback based slip control (driven wheel speed based to undriven
wheel speed)