MODIFIED STATIC TIRE MODEL FOR PROVIDING ASSIST WITHOUT A TORQUE SENSOR FOR ZERO TO LOW VEHICLE SPEEDS

摘要

A method of controlling an electric power steering system is provided. The method estimates steering rack force to be caused by a tire and a surface of a ground with which the tire is in contact in response to determining that one or more hand wheel torque sensors are not enabled. The method generates a steering assist torque command based on the estimated steering rack force. The method controls the electric power steering system using the steering assist torque command.