Quote:
Originally Posted by lemon1324
How do you determine if a wheel is slipping when all four wheels are powered?
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Most would say you need an unpowered wheel (and now that a speed sensor is legal, it seems to be the simplest method), but consider the case of a 4-wheel drive vehicle that has implemented traction control. The answer given by MikeE is similar to what is used in the real world. Yes, there are some considerations regarding the effects of the motors on speed, but if we assume we know the input (i.e., PWM value to the motor) we can use that to filter out those effects from the output (wheel speed second derivative)
You can also set a maximum allowable acceleration using an accelerometer. Discount the occasional collision of course, and make it easily disabled for those cases where you have that sliver of carpet under your wheels.
However, Paul Copioli mentioned that joystick control is effective, and I tend to favor the simple solution. And we'll disable that when the trigger is pulled...
Quote:
Originally Posted by Doug Leppard
How about tracking the speed of a wheel and when the speed greatly increases more than normal what is expected bring the power back.
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Exactly the second derivative of wheel speed - the rate of wheel acceleration.