A vehicle power steering system has a steering shaft with a rotational position sensor providing signal rollover so that each sensor output indicates a plurality of potential absolute steering positions separated from each other by multiples of a rollover angle. Upon each initiation of vehicle operation,...http://www.google.com/patents/US6039144?utm_source=gb-gplus-sharePatent US6039144 - Apparatus and method for producing a desired return torque in a vehicle power steering system having a rotational steering position sensor
