Power steering architecture without mechanical connection between the steering wheel and the steering mechanism of the vehicle

Patent metadata

Field	Value
Publication number	US-12570358-B2
Application number	US-202418781070-A
Country	US
Kind code	B2
Filing date	Jul 23, 2024
Priority date	Jul 25, 2023
Publication date	Mar 10, 2026
Grant date	Mar 10, 2026

Abstract

A method for controlling a power steering system of a motor vehicle, the method including steps of: detecting an operating state of a steering actuator coupled to a rack; when the steering actuator is operational, providing a torque setpoint to a main motor of the steering actuator, by a first control unit of the steering actuator; when the steering actuator is faulty, but provides an angular position measurement of the main motor, controlling, by a second control unit, a brushless auxiliary motor, coupled to the rack, based on measuring the angular position of the main motor and an angular position of a steering wheel; and when the steering actuator has completely failed, controlling the auxiliary motor according to the angular position of the steering wheel.

First claim

The invention claimed is:

1 . A method for controlling a power steering system of a motor vehicle, the method comprising:
detecting an operating state of a steering actuator mechanically coupled to a first steering pinion engaged with a steering rack of the motor vehicle; when the steering actuator is operational, providing, by a first control unit of the steering actuator, a torque setpoint to a main motor of the steering actuator; when the steering actuator fails, but provides an angular position measurement of the main motor, controlling, by a second control unit, a brushless auxiliary motor, mechanically coupled to a second steering pinion engaged with the steering rack, using a closed-loop angle regulation function receiving the angular position measurement of the main motor and an angular position measurement of a steering wheel of the vehicle; and when the steering actuator has completely failed, controlling the auxiliary motor by the second control unit, using an open-loop angle regulation function receiving the angular position measurement of the steering wheel.

2 . The method according to claim 1 , wherein the second control unit belongs to a force feedback actuator coupled to the steering wheel.

3 . The method according to claim 1 , wherein the auxiliary motor is controlled by the second control unit via a power circuit installed in a force feedback actuator coupled to the steering wheel.

4 . The method according to claim 1 , further comprising:
when the steering actuator fails, mechanically coupling the auxiliary motor to the second steering pinion using a clutch; and when the steering actuator is operational, mechanically decoupling the auxiliary motor from the second steering pinion using the clutch.

5 . The method according to claim 1 , further comprising:
when the steering actuator is operational, supplying, by the second control unit, a torque setpoint to the auxiliary motor in addition to the torque setpoint supplied to the main motor of the steering actuator.

6 . A power steering system for a motor vehicle, the system comprising:
a steering actuator comprising a main motor mechanically coupled to a first steering pinion engaged with a steering rack of the motor vehicle, and a first control unit configured to control the main motor, a brushless auxiliary motor mechanically coupled to a second steering pinion engaged with the steering rack, and a second control unit configured to control the auxiliary motor by implementing the method according to claim 1 .

7 . The system according to claim 6 , comprising a force feedback actuator coupled to the steering wheel and comprising the second control unit.

8 . The system according to claim 7 , wherein the force feedback actuator comprises a first power circuit connected to the second control unit and to a force feedback motor coupled to the steering wheel, the second control unit being configured to control the force feedback motor.

9 . The system according to claim 7 , wherein the force feedback actuator comprises a second power circuit connected to the second control unit and to the auxiliary motor, to allow the second control unit to control the auxiliary motor.

10 . The system according to claim 6 , comprising a clutch for mechanically coupling the auxiliary motor to the second steering pinion, the clutch being controlled by the second control unit.

11 . The system according to claim 6 , wherein the auxiliary motor is sized to only allow parking maneuvers of the vehicle.

12 . A motor vehicle comprising a power steering system according to claim 6 .

Assignees

• Jtekt Europe Sas

Inventors

• Trebuchon Jean-Michel

Classifications

• B62D5/003 Primary

  Backup systems, e.g. for manual steering (B62D5/30 takes precedence) · CPC title

• B62D5/0478

  Clutches · CPC title

• B62D5/0484

  for reaction to failures, e.g. limp home · CPC title

• B62D5/0487

  detecting motor faults (B62D5/0496 takes precedence) · CPC title

• B62D5/046 Primary

  Controlling the motor · CPC title