I've been trying to think of a way that this could be done without putting a bunch of cumpooter stuff in between the driver and the vehicle.
I think some safety parameters such as a "max rpm" in the motor controller would be a good start, whether or not this double motor idea is used. It could be derived from the motor frequency data, and really wouldn't matter what the other motor is doing. (just for a safety limit) More advanced code could provide traction control - which of course would be regen ABS!
I love the cutting brake concept. I've been trying to think of a way the steering position could be used without adding a bunch of microcontroller code complexity.
One idea is this: a simple analog circuit that would allow a driver to balance the throttle input. It could be a circuit where one input is the throttle, a second input determines the balance of the two outputs. each output goes to a different motor controller. Now, this could be adjusted on the fly, either by the driver or some mechanism that senses steering position.
I'll bet it could be as simple as two op-amps set up as differential amplifiers; they both get the throttle input for one input and a different bias input depending on the balance signal. All this could be implemented with extremely reliable mil-spec hardware and a bypass switch if things go awry.
In an AWD setup, the driver could even balance the fore/aft torque balance while steering position, relative motor speeds, or an accelerometer adjust left-right torque balance. Rally race car drivers would be jealous.
-e*clipse