Power saving mode for steering systems of a motor vehicle

Patent metadata

Field	Value
Publication number	US-12509141-B2
Application number	US-202217969015-A
Country	US
Kind code	B2
Filing date	Oct 19, 2022
Priority date	Apr 20, 2020
Publication date	Dec 30, 2025
Grant date	Dec 30, 2025

Abstract

A method for power saving in a steering system of a motor vehicle including a road wheel actuator acting on a rack to turn steerable road wheels and a controller configured or programmed to generate an operation signal for the road wheel actuator, wherein the controller includes a position controller to generate a motor torque request based on an actual and/or a measured position of the rack and a requested rack position, includes detecting a passive mode of the steering system by a passive mode detector of the controller if the motor vehicle is stopped and no steering input is provided, and if a passive mode is detected by the passive mode detector, setting the motor torque request to zero in order to save power.

First claim

What is claimed is:

1 . A method for power saving in a steering system of a motor vehicle including a road wheel actuator acting on a rack to turn steerable road wheels and a controller configured or programmed to generate an operation signal for the road wheel actuator, the controller including a position controller configured or programmed to generate a motor torque request based on an actual and/or a measured position of the rack and a requested rack position, the method comprising:
detecting a passive mode of the steering system with a passive mode detector of the controller in response to the motor vehicle being stopped and no steering input being provided; and in response to the passive mode being detected by the passive mode detector, setting the motor torque request to substantially zero in order to save power.

2 . The method according to claim 1 , wherein the motor torque request is set to substantially zero by usage of a torque limiter, which limits the motor torque request gradually to substantially zero in response to a passive mode being detected.

3 . The method according to claim 2 , wherein the torque limiter gradually increases a limit value to a predefined maximum value in response to a signal from the passive mode detector indicating that the motor vehicle is activated and that the passive mode is no longer present.

4 . The method according to claim 1 , wherein the motor torque request is set to substantially zero by modifying the requested rack position.

5 . The method according to claim 4 , wherein the requested rack position is gradually modified by ramping a previous modification of the requested rack position to substantially zero if a signal from the passive mode detector indicates that the motor vehicle is activated and that the passive mode is no longer present.

6 . A steer-by-wire-steering system of a motor vehicle configured or programmed to carry out the method according to claim 1 .

7 . The steer-by-wire-steering system according to claim 6 , wherein the rack is part of a front axle or a rear axle.

8 . The method according to claim 1 , further comprising permitting the steerable road wheels to be turned in response to a signal from the passive mode detector indicating that the motor vehicle is activated and that the passive mode is no longer present.

Assignees

• Thyssenkrupp Presta Ag
• Honda Motor Co Ltd

Inventors

• Pásztor Levente
• Benyo Imre
• Kakas Péter
• Ojima Yosuke
• Hanji Munetsugu
• Miyakawa Hayato
• Watanabe Yoshinobu

Classifications

• B62D5/001

  Mechanical components or aspects of steer-by-wire systems, not otherwise provided for in this maingroup · CPC title

• B62D5/0481

  monitoring the steering system, e.g. failures · CPC title

• B62D6/02

  responsive only to vehicle speed · CPC title

• B62D5/0463 Primary

  calculating assisting torque from the motor based on driver input · CPC title

• B62D6/002 Primary

  computing target steering angles for front or rear wheels (B62D7/159 takes precedence) · CPC title