An electric power steering system includes a steering wheel, an electric
assist motor operatively coupled to the steering wheel, and an electronic
controller operatively coupled to the motor for receiving a first signal
representative of torque applied to the steering wheel, and a second
signal representative of angular velocity of the motor. The electronic
controller produces an active damping motor command signal according to a
function of the first and second signals. The active damping motor
command signal is scaled by a first factor if the first and second
signals are both positive, or if the first and second signals are both
negative, to provide a scaled motor command signal. The active damping
motor command signal is scaled by a second factor if the first signal is
positive and the second signal is negative, or if the first signal is
negative and the second signal is positive, to provide the scaled motor
command signal. The scaled motor command signal is applied to the motor.