Providing assist torque without hand wheel torque sensor for zero to low vehicle speeds

摘要

A method of controlling an electric power steering system of a vehicle is provided. The method estimates steering rack force to be caused by a tire of the vehicle 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 of the vehicle 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.

主权项

1. A method of controlling an electric power steering system of a vehicle, the method comprising:
filtering a hand wheel angle with a low-pass filter; filtering a hand wheel velocity with a low-pass filter; determining that one or more hand wheel torque sensors of the vehicle are not enabled; estimating steering rack force caused by a tire of the vehicle and a surface of a ground with which the tire is in contact with the filtered hand wheel angle and the filtered hand wheel velocity; generating a steering assist torque command based on the estimated steering rack force; and controlling the electric power steering system using the steering assist torque command.