Special operating procedure for a vehicle's steering system

Abstract

Method for operating a steering system of a vehicle, wherein a control unit of a steering system of a vehicle controls an electric motor of the steering system designed to generate a hand torque and rotatably coupled to a steering column of the steering system, as well as steering system for a vehicle and vehicle.

Description

The invention relates to a method for operating a steering system of a vehicle. Furthermore, the invention relates to a steering system for a vehicle and a vehicle. According to the invention, the steering system comprises a steering column and a steering wheel fixed to the steering column. The steering system serves to continuously adjust a desired yaw angle of, in particular, two wheels, especially two front wheels, of the vehicle during travel, i.e., to steer the vehicle. The steering wheel can also include controls, such as switches, and / or functional systems, such as a restraint system. Furthermore, the steering wheel can serve as an output or display unit for the vehicle. EP 4 147 907 A1 discloses a method for operating a vehicle steering wheel in which a vibration device integrated into a vehicle steering wheel causes the steering wheel to vibrate in order to issue a notification and / or a warning from the vehicle. CN 115 123 070 A also discloses a method for operating a steering wheel in which a vibration motor of the steering wheel generates a vibration warning, wherein a vibration frequency corresponds to a warning level. It is an object of the invention to provide a method for operating a steering system that provides vibration of the steering wheel without a dedicated vibration device in the steering wheel. Further objects of the invention are to provide a steering system for a vehicle and a vehicle. An object of the invention is a method for operating a vehicle's steering system, in which a control unit of the vehicle's steering system controls an electric motor of the steering system, which is designed to generate a steering torque and is rotatably coupled to a steering column of the steering system. The steering system is a steer-by-wire steering system, also known as electric power steering (EPS), in which a mechanical coupling of the vehicle's steering gear to the steering column is absent. Instead, an angle sensor detects a steering angle and provides a sensor signal corresponding to the detected angle. A control unit of the steering system controls a further electric motor of the steering system, which is rotatably coupled to the steering gear, depending on the provided rotation signal. To compensate for the lack of mechanical coupling between the steering column and the steering gear, the electric motor, which is coupled to the steering column in a rotating manner, generates a torque called hand torque, which opposes any deflection of the steering wheel from the straight-ahead position. According to the invention, the electric motor controlled by the control unit provides an oscillating torque to the steering column, causing the steering column, which is subjected to this oscillating torque, to vibrate the steering wheel of the steering system, which is fixed to the steering column. The electric motor, which is already coupled to the steering column in a rotating manner, is used to vibrate the steering wheel. Accordingly, the steering wheel does not need to include an integrated vibration device to indicate or output tactilely perceptible signals. The additional use of the electric motor coupled to the steering column in a rotating manner reduces the functional complexity of the steering wheel by eliminating the need for a dedicated vibration device. Furthermore, the available installation space within the steering wheel is increased. It is noted that the term "oscillating" here refers, as usual, to a periodically alternating deflection movement relative to a zero point. In previously known operating methods, the torque provided by the electric motor, which is rotatably coupled to the steering column, depends on the steering angle of the steering wheel and is not inherently periodic. A torque independent of the steering angle has not yet been provided by the electric motor rotatably coupled to the steering column. The amplitude of the provided oscillating torque is preferably low. In the context of the invention, the amplitude is low if it is significantly smaller than the hand torque provided by the electric motor. In this way, the oscillating torque can be superimposed on the hand torque even while the vehicle is in motion, without compromising the vehicle's safety. A high frequency of the supplied oscillating torque is advantageous. In the context of the invention, the frequency is considered high if it is significantly greater than the maximum possible manual steering frequency. This allows the oscillating torque to be superimposed on the hand torque even while the vehicle is in motion, without compromising vehicle safety. The oscillation of the supplied oscillating torque can vary over time. In other words, the oscillating torque can temporarily exhibit a reduced amplitude or pause. Furthermore, the time intervals with reduced amplitude or pause intervals can have a variable length. In particular, the oscillation of the provided oscillating torque exhibits a predetermined rhythm. A rhythm within the meaning of the invention is a predetermined regular temporal sequence of different amplitudes of the oscillating torque. The generated oscillating torque ideally simulates a tactilely perceptible heartbeat of the vehicle for a hand resting on the steering wheel. This tactile heartbeat can correspond to an audibly perceptible sound emitted by the vehicle simulating a heartbeat. In particular, the control unit can synchronize the tactile heartbeat with the audibly perceptible heartbeat and, if applicable, visually perceptible display content or light signals. In one embodiment, the control unit provides the oscillating torque when a sensor in the steering system detects a hand resting on the steering wheel. The oscillating torque is only provided if it can be tactilely perceived by the driver. Providing the oscillating torque without the possibility of tactile perception is avoided. In another embodiment, the control unit provides the oscillating torque when the vehicle is stationary. This provision can occur, for example, after the driver enters the vehicle or after the vehicle's engine is started, or before the driver exits the vehicle or after the engine is switched off. A further aspect of the invention is a steering system for a vehicle, comprising a steering column, a steering wheel fixed to the steering column, an electric motor rotatably coupled to the steering column for generating a hand torque, and a control unit functionally connected to the electric motor. The steering system is a steer-by-wire system, i.e., an EPS system. According to the invention, the steering system is configured to execute a method according to one embodiment of the invention. The steering system can vibrate the steering wheel without a dedicated vibration device in the steering wheel. In this way, the functionality of the steering system is increased. Another object of the invention is a vehicle. The vehicle is preferably, but not exclusively, a road vehicle, in particular a passenger car. Vehicles within the meaning of the invention also include rail vehicles, watercraft, and aircraft. According to the invention, the vehicle comprises a steering system according to one embodiment of the invention. The steering system enables the vehicle to vibrate a steering wheel of the steering system without a dedicated vibration device in the steering wheel. In this way, the vehicle can be perceived by the driver by means of another sense, namely the sense of touch. A significant advantage of the operating method according to the invention is that steering wheel vibration is provided without a dedicated vibration device in the steering wheel. In this way, it becomes possible, for example, to represent a trademark-like symbol, in particular a heartbeat, in a tactilely perceptible manner. The invention is schematically illustrated in the drawings with reference to one embodiment and is further described with reference to the drawings. Figure 1 shows a partial perspective view of a vehicle according to one embodiment of the invention. Fig. 1 shows a partial perspective view of a vehicle 1 according to an embodiment of the invention. The vehicle 1 comprises a steering system 2 according to an embodiment of the invention. The steering system 2 is suitable for the vehicle 1 and comprises a steering column 20, a steering wheel 22 fixed against rotation on the steering column 20, an electric motor 21 rotatably coupled to the steering column 20 for generating a hand torque, and a control unit 23 functionally connected to the electric motor 21. Furthermore, the steering system 2 comprises a steering gear 24. The steering system 2 is configured to operate the steering system 2 of the vehicle 1 by performing a method according to an embodiment of the invention as follows. The control unit 23 of the steering system 2 of the vehicle 1 controls the electric motor 21 of the steering system 2, which is designed to generate a hand torque and is rotatably coupled to the steering column 20 of the steering system 2. The electric motor 21, controlled by the control unit 23, provides an oscillating torque 4 to the steering column 20. The amplitude of the provided oscillating torque 4 is preferably low. The frequency of the provided oscillating torque 4 is advantageously high. The oscillation of the provided oscillating torque 4 can vary over time and / or have a predetermined rhythm. Ideally, the provided oscillating torque 4 simulates a tactilely perceptible heartbeat of the vehicle 1 for the hand 3 of a driver of the vehicle 1 resting on the steering wheel 22. The control unit 23 can provide the oscillating torque 4 when a sensor of the steering system 2 detects a driver's hand 3 resting on the steering wheel 22 of the vehicle 1. Alternatively or additionally, the control unit 23 can provide the oscillating torque 4 when the vehicle 1 is stationary. The steering column 20, subjected to the provided oscillating torque 4, causes the steering wheel 22 of the steering system 2, which is held non-rotatably on the steering column 20, to vibrate. REFERENCE MARK LIST: 1 Vehicle 2 Steering system 20 Steering column 21 Electric motor 22 Steering wheel 23 Control unit 24 Steering gear 3 Hand 4 Oscillating torque QUOTES INCLUDED IN THE DESCRIPTION This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature EP 4 147 907 A1

[0004] CN 115 123 070 A

[0005]

Claims

Method for operating a steering system (2) of a vehicle (1), in which: - a control unit (23) of a steering system (2) of a vehicle (1) controls an electric motor (21) of the steering system (2) which is designed to generate a hand torque and is rotatably coupled to a steering column (20) of the steering system (2); - the electric motor (21) controlled by the control unit (23) provides an oscillating torque (4) for the steering column (20); and - the steering column (20) subjected to the provided oscillating torque (4) causes a steering wheel (22) of the steering system (2) which is held non-rotatably on the steering column (20). Method according to claim 1, wherein the amplitude of the provided oscillating torque (4) is small. Method according to claim 1 or 2, wherein the frequency of the provided oscillating torque (4) is high. Method according to one of claims 1 to 3, wherein the oscillation of the provided oscillating torque (4) varies over time. Method according to any one of claims 1 to 4, wherein the oscillation of the provided oscillating torque (4) has a predetermined rhythm. Method according to one of claims 1 to 5, wherein the provided oscillating torque (4) simulates a heartbeat of the vehicle (1) in a tactilely perceptible manner for a hand (3) of a driver of the vehicle (1) resting on the steering wheel (22). Method according to any one of claims 1 to 6, wherein the control unit (23) provides the oscillating torque (4) when a sensor of the steering system (2) detects a hand (3) of a driver of the vehicle (1) resting on the steering wheel (22). Method according to any one of claims 1 to 7, wherein the control unit (23) provides the oscillating torque (4) when the vehicle (1) is stationary. Steering system (2) for a vehicle (1), comprising a steering column (20), a steering wheel (22) fixed to the steering column (20) in a rotationally fixed manner, an electric motor (21) rotatably coupled to the steering column (20) for generating a hand torque and a control unit (23) functionally connected to the electric motor (21), wherein the steering system (2) is configured to carry out a method according to one of the preceding claims. Vehicle (1) comprising a steering system (2) according to claim 9.

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