As an alternative consider working out the maximum possible rate of
acceleration that the vehicle can sustain in practice  and then monitor rate
of change of engine or shaft revs to see if the car appears to be breaking
the laws of Physics. If so you are wheel spinning and you can adjust the
throttle to keep it at but not above this limit.

Hey! - this suddenly sounds immensely like Peter Betts recent dF/dT
 thread - I wonder if they are related?



RM


>I'm planning to make a traction control system for a glowplug engine
>radio controlled car. Thought this would be a good practical
>application. I intend to use reflection detectors and some standard
>counter circuits to count the number of revs on the front wheel (which
>is not being powered from the engine) and on the crankshaft of the
>engine.
>
>Imagine that the gear ratio is 10:1, then I'd simply read the counter
>value ten times as often for the engine than for the front wheel, thus
>removing the need for divisions. By comparing these values I could see
>if the traction is being lost.