Patent Number: 6,637,544

Title: Relating to electrical power assisted steering systems

Abstract: An electric power assisted steering system is disclosed in which a torque demand signal (8) is generated and applied to an electric motor (1) operatively connected to a steering mechanism (5) in order to assist a driver of the vehicle when steering the vehicle. The torque demand signal (8) includes a damping component that is dependent upon a measurement of torque T carried by the steering mechanism and a measurement of the angular velocity .omega. of the steering mechanism. The torque produced by the motor (1) is not obtrusive during "hands-on" manoeuvers but provides enhanced damping in other manoeuvers such as a steering flick.

Inventors: Stevens; Simon David (Birmingham, GB), Burton; Anthony Walter (West Midlands, GB), Williams; Andrew James Stephen (West Midlands, GB), Cheel; John Nicholas (Birmingham, GB), Jones; Russell Wilson (Warwickshire, GB)

Assignee: TRW Lucas Varity Electric Steering Ltd.

International Classification: B62D 5/04 (20060101); B62D 6/00 (20060101); B62D 005/04 ()

Expiration Date: 10/28/2020