Steering system with active compensation for road disturbances

A vehicle comprising:

• a steering wheel;
• a steering wheel sensor coupled to the steering wheel and configured to sense rotation of the steering wheel;
• road wheels mounted to the vehicle;
• a steering system coupling the steering wheel to the road wheels, the steering system including a superimposition gear mechanism engaging the steering wheel and the road wheels;
• an assist motor coupled to the superimposition gear mechanism, the assist motor configured to control a superimposition angle imposed by the superimposition gear mechanism;
• a controller coupled to the steering wheel sensor and the assist motor, the controller programmed to:
• control the superimposition angle imposed by the assist motor as a function of a steering angle of the steering wheel;
• detect an external disturbance to road wheels of a vehicle caused by one of a projection and a hole in a road;
• and
• in response to detecting the external disturbance, adjust power supplied to the assist motor effective to adjust the superimposition angle such that compliance between the road wheels and the steering wheel is increased and an amount of torque transmitted between the road wheels and the steering wheel as a result of the external disturbance is reduced.