US Patent RE40268 Wheel lift identification for an automotive vehicle

A system for detecting wheel lift of an automotive vehicle has a speed sensor (22) coupled to a wheel (12) of automotive vehicle (10). A torque control system (20) is coupled to wheel (12) to change the torque at the wheel. A controller (18) is coupled to the torque control system and a speed sensor. The controller (18) determines lift by changing the torque of the wheel, measuring the change in torque and indicating lift in response to change in torque which may be indicated by wheel speed.