Method for operating an electromechanically assisted steering system

Patent metadata

Field	Value
Publication number	US-12145662-B2
Application number	US-202217957626-A
Country	US
Kind code	B2
Filing date	Sep 30, 2022
Priority date	Oct 1, 2021
Publication date	Nov 19, 2024
Grant date	Nov 19, 2024

Abstract

A method for operating an electromechanically assisted steering system of a motor vehicle is described. The steering system has a steering arrangement and at least one electromechanical actuator. The at least one electromechanical actuator is coupled to the steering arrangement in a torque-transmitting manner. The method comprises the following steps:
acquiring a steering rack force signal that comprises information about a steering rack force acting on a steering rack of the steering system; acquiring a driver torque signal that comprises information about a driver torque exerted on the steering arrangement by the driver; ascertaining a filtered scaled steering rack force signal; and ascertaining a steering feedback torque for the at least one electromechanical actuator, based on the scaled steering rack force signal.

A control device for an electromechanically assisted steering system of a motor vehicle, an electromechanically assisted steering system, and a computer program are also described.

First claim

The invention claimed is:

1. A method for operating an electromechanically assisted steering system of a motor vehicle, wherein the steering system has a steering arrangement and at least one electromechanical actuator, wherein the at least one electromechanical actuator is coupled to the steering apparatus in a torque-transmitting manner, comprising the following steps:
acquiring a steering rack force signal that comprises information about a steering rack force acting on a steering rack of the steering system;
acquiring a driver torque signal that comprises information about a driver torque exerted on the steering arrangement by the driver;
ascertaining a filtered scaled steering rack force signal, wherein the acquired steering rack force signal is filtered by way of a filter designed as a high-pass filter or bandpass filter and the resultant filtered steering rack force signal is scaled on the basis of the acquired driver torque signal in order to ascertain the filtered scaled steering rack force signal; and
ascertaining a steering feedback torque for the at least one electromechanical actuator based on the filtered scaled steering rack force signal.

2. The method as claimed in claim 1 , wherein a speed signal is acquired, this comprising information about a speed of the motor vehicle.

3. The method as claimed in claim 2 , wherein the speed signal is overlaid with the driver torque signal in order to ascertain a speed-dependent driver torque signal, wherein the acquired steering rack force signal is scaled with the speed-dependent driver torque signal in order to obtain the filtered scaled steering rack force signal.

4. The method as claimed in claim 2 , wherein the model-based steering rack force signal is overlaid with the speed signal.

5. The method as claimed in claim 2 , wherein the speed signal is overlaid with the driver torque signal in order to ascertain a speed-dependent driver torque signal, wherein the filtered steering rack force signal is scaled with the speed-dependent driver torque signal in order to obtain the filtered scaled steering rack force signal.

6. The method as claimed in claim 2 , wherein the low-pass-filtered steering rack force signal is overlaid with the speed signal, and wherein the steering feedback torque is ascertained based on the overlaid signal including the low-pass-filtered steering rack force signal and the speed signal.

7. The method as claimed in claim 1 , wherein the acquired steering rack force signal is filtered by way of a low-pass filter, thereby giving a low-pass-filtered steering rack force signal, and wherein the steering feedback torque is ascertained on the basis of the low-pass-filtered steering rack force signal.

8. The method as claimed in claim 7 , wherein the low-pass-filtered steering rack force signal is overlaid with the speed signal, and wherein the steering feedback torque is ascertained based on the overlaid signal including the low-pass-filtered steering rack force signal and the speed signal.

9. The method as claimed in claim 1 , wherein a model-based steering rack force signal is ascertained based on a motor vehicle model.

10. The method as claimed in claim 9 , wherein the model-based steering rack force signal is overlaid with the speed signal, and wherein the steering feedback torque is ascertained based on the overlaid signal including the model-based steering rack force signal and the speed signal.

11. A control device for an electromechanically assisted steering system of a motor vehicle, wherein the steering system has a steering arrangement and an electromechanical steering aid having at least one electromechanical actuator, wherein the at least one electromechanical actuator is coupled to the steering arrangement in a torque-transmitting manner, and wherein the control device is designed to prompt the steering system to perform a method as claimed in claim 1 .

12. An electromechanically assisted steering system, having a control device as claimed in claim 11 , a steering arrangement and an electromechanical steering aid, wherein the electromechanical steering aid has at least one electromechanical actuator that is coupled to the steering arrangement in a torque-transmitting manner.

13. The electromechanically assisted s system as claimed in claim 12 , wherein the electromechanically assisted steering system is designed as an EPS steering system or as a steer-by-wire steering system.

14. The method as claimed in claim 1 , wherein the steering feedback torque is additionally ascertained on the basis of the speed signal.

15. The method as claimed in claim 14 , wherein the steering feedback torque is ascertained on the basis of the model-based steering rack force signal.

16. A method for operating an electromechanically assisted steering system of a motor vehicle, wherein the steering system has a steering arrangement and at least one electromechanical actuator, wherein the at least one electromechanical actuator is coupled to the steering apparatus-in a torque-transmitting manner, comprising the following steps:
acquiring a steering rack force signal that comprises information about a steering rack force acting on a steering rack of the steering system;
acquiring a driver torque signal that comprises information about a driver torque exerted on the steering arrangement by the driver;
ascertaining a filtered scaled steering rack force signal, wherein the acquired steering rack force signal is scaled, inter alia, on the basis of the acquired driver torque signal and the resultant scaled steering rack force signal is filtered by way of a filter ( 28 ) designed as a high-pass filter or bandpass filter in order to ascertain the filtered scaled steering rack force signal; and
ascertaining a steering feedback torque for the at least one electromechanical actuator based on the filtered scaled steering rack force signal.

Assignees

• Zf Automotive Germany Gmbh

Inventors

• Hambloch Peter
• Bergmann Philipp

Classifications

• B62D6/008 Primary

  Control of feed-back to the steering input member, e.g. simulating road feel in steer-by-wire applications · CPC title

• B62D5/006 Primary

  power actuated · CPC title