Abstract: An electric power assisted steering assembly comprises a steering mechanism which operatively connects a steering wheel to the roadwheels of a vehicle, a sensor adapted to produce a first output signal indicative of the torque carried by a portion of the steering mechanism and to produce a second output signal indicative, an electric motor, a signal processing unit having a lead-lag filter to produce an overall torque demand signal, and a motor drive stage adapted to provide a drive current to the motor responsive to the torque demand signal.

Abstract: An electric power steering system includes a control for providing a calculated torque assist demand in the event of failure of a steering wheel torque sensor. The control is responsive to one or more of a vehicle speed, a steering column position, a steering column velocity, a gear lever position, a vehicle yaw rate and a vehicle lateral acceleration for generating the calculated torque assist demand. The control is operable to modify the torque assist demand by providing one or more of (a) friction and inertial compensation, (b) vehicle oversteer compensation, (c) reverse motion compensation, (d) damping compensation and (e) self steer prevention.

Abstract: An electric power steering system includes a control for providing a calculated torque assist demand in the event of failure of a steering wheel torque sensor. The control is responsive to one or more of a vehicle speed, a steering column position, a steering column velocity, a gear lever position, a vehicle yaw rate and a vehicle lateral acceleration for generating the calculated torque assist demand. The control is operable to modify the torque assist demand by providing one or more of (a) friction and inertial compensation, (b) vehicle oversteer compensation, (c) reverse motion compensation, (d) damping compensation and (e) self steer prevention.

Abstract: An electric power assisted steering assembly comprises a steering mechanism which operatively connects a steering wheel to the roadwheels of a vehicle, a torque sensing means adapted to produce a first output signal indicative of the torque carried by a portion of the steering mechanism, a means for producing a second output signal indicative from a signal indicative of the angular velocity of the portion of the steering mechanism, an electric motor operatively connected to the steering mechanism, a signal processing unit adapted to receive the two output signals and to produce therefrom an overall torque demand signal representative of a torque to be applied to the steering mechanism by the motor, and a motor drive stage adapted to provide a drive current to the motor responsive to the torque demand signal. The overall torque demand signal includes a damping component that is dependent upon the second output signal.