WO2024017488A1 - Steer-by-wire system with automatic power on mode - Google Patents

Steer-by-wire system with automatic power on mode Download PDF

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Publication number
WO2024017488A1
WO2024017488A1 PCT/EP2022/076006 EP2022076006W WO2024017488A1 WO 2024017488 A1 WO2024017488 A1 WO 2024017488A1 EP 2022076006 W EP2022076006 W EP 2022076006W WO 2024017488 A1 WO2024017488 A1 WO 2024017488A1
Authority
WO
WIPO (PCT)
Prior art keywords
steer
vehicle
wire system
hand wheel
steering
Prior art date
Application number
PCT/EP2022/076006
Other languages
French (fr)
Inventor
Alain CONTE-TISNERAT
Michel MOUTARDE
Vitali STEPHANE
Original Assignee
HELLA GmbH & Co. KGaA
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by HELLA GmbH & Co. KGaA filed Critical HELLA GmbH & Co. KGaA
Publication of WO2024017488A1 publication Critical patent/WO2024017488A1/en

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
    • B62D—MOTOR VEHICLES; TRAILERS
    • B62D6/00—Arrangements for automatically controlling steering depending on driving conditions sensed and responded to, e.g. control circuits
    • B62D6/002—Arrangements for automatically controlling steering depending on driving conditions sensed and responded to, e.g. control circuits computing target steering angles for front or rear wheels
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
    • B62D—MOTOR VEHICLES; TRAILERS
    • B62D5/00—Power-assisted or power-driven steering
    • B62D5/001—Mechanical components or aspects of steer-by-wire systems, not otherwise provided for in this maingroup
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
    • B62D—MOTOR VEHICLES; TRAILERS
    • B62D15/00—Steering not otherwise provided for
    • B62D15/02—Steering position indicators ; Steering position determination; Steering aids
    • B62D15/0205—Mechanical indicators, e.g. in or near steering wheel
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
    • B62D—MOTOR VEHICLES; TRAILERS
    • B62D15/00—Steering not otherwise provided for
    • B62D15/02—Steering position indicators ; Steering position determination; Steering aids
    • B62D15/021—Determination of steering angle
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
    • B62D—MOTOR VEHICLES; TRAILERS
    • B62D15/00—Steering not otherwise provided for
    • B62D15/02—Steering position indicators ; Steering position determination; Steering aids
    • B62D15/025—Active steering aids, e.g. helping the driver by actively influencing the steering system after environment evaluation
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
    • B62D—MOTOR VEHICLES; TRAILERS
    • B62D5/00—Power-assisted or power-driven steering
    • B62D5/04—Power-assisted or power-driven steering electrical, e.g. using an electric servo-motor connected to, or forming part of, the steering gear
    • B62D5/0457—Power-assisted or power-driven steering electrical, e.g. using an electric servo-motor connected to, or forming part of, the steering gear characterised by control features of the drive means as such
    • B62D5/0481—Power-assisted or power-driven steering electrical, e.g. using an electric servo-motor connected to, or forming part of, the steering gear characterised by control features of the drive means as such monitoring the steering system, e.g. failures

Definitions

  • the present invention relates to a steer-by-wire system for a vehicle for a motor vehicle.
  • the invention also relates to a motor vehicle with a generic steer-by-wire system.
  • Conventional steering systems comprise a hand wheel for being operated by a driver of a vehicle, a steering rack for transmitting a steering angle to road wheels of the vehicle and a steering column for transmitting the steering angle from the hand wheel to the steering rack.
  • conventional steering systems For supporting the driver by reducing a steering torque on the hand wheel, conventional steering systems further comprise steering actuators, such as servo- electronic steering actors.
  • a steering system which comprises a steering rack without a direct mechanical coupling to the hand wheel.
  • Such steering systems are also known as steer-by-wire steering systems or steer-by-wire systems.
  • the US- parent application US 2022 10212715 A1 discloses an example for a steer-by-wire system with a tilt position adjustment mechanism for tilting a steering column.
  • Steer-by-wire systems have the advantage over conventional steering systems that a steering angle of the steering rack can be steered without rotating the hand wheel. Furthermore, the hand wheel can be rotated without affecting the steering rack. Thus, unwanted interactions between the driver and the steering rack or the steering wheel and the driver can be avoided, especially during the performance of an automated steering function of the vehicle.
  • the present invention provides a steer-by-wire system for a vehicle with the features of the independent claim 1 and a vehicle with the features of the subordinate claim 10. Further features and details of the invention emerge from the subclaims, the description and the drawings. Features and details that are described in connection with the steer-by-wire system according to the invention naturally also apply in connection with the vehicle according to the invention and vice versa, so that with regard to the disclosure of the individual aspects of the invention, reference is or can always be made to each other.
  • a steer-by-wire system for a vehicle.
  • the steer-by-wire system comprises a hand wheel for receiving a desired steering angle of a driver of the vehicle, a steering column stub for holding the hand wheel, a hand wheel actuator, connected to the steering column stub for providing a mechanical feedback from steered road wheels of the vehicle to the hand wheel, a steering angle sensor for sensing a steering angle of the hand wheel, a road wheel actuator for transmitting the steering angle of the hand wheel to a steering rack of the steer-by wire system and an electronic control unit for processing data from the steering angle sensor and the road wheel actuator and for controlling the hand wheel actuator and the road wheel actuator in an operational mode.
  • the steer-by-wire system comprises a detection device for detecting a change in an orientation parameter on the vehicle and to activate the electronic control unit from a sleep mode to the operational mode when a detected change in the orientation parameter exceeds a predetermined threshold.
  • the hand wheel is configured for receiving the desired steering angle of a driver of the vehicle. It is preferred that the hand wheel is configured for being retracted, received by a reception of a dashboard of the vehicle or the like, in order to improve a boarding and disembarking for the driver, to improve the comfort for the driver during an autonomous driving mode of the vehicle or the like.
  • the steer-by-wire system is configured for locking the hand wheel, e.g. for keeping the hand wheel in a predetermined position during the autonomous driving mode, in a parking mode or the like.
  • the hand wheel is connected to an upper end of the steering column stub. Thus, the steering column stub is holding the hand wheel.
  • the hand wheel is connected to the steering column stub such that a steering angle of the hand wheel is transmitted to the steering column stub and that a rotational or vibrational movement of the steering column stub is transmitted to the hand wheel.
  • the steering column stub is denoted stub because it is usually shorter than ordinary steering columns of conventional steering systems and does not provide a direct mechanical coupling with the steering rack.
  • the steering column stub is mechanically connected to the hand wheel actuator and the steering sensor.
  • the hand wheel actuator is configured for providing a mechanical feedback from steered road wheels of the vehicle to the hand wheel.
  • the hand wheel actuator can be configured for transmitting a steering angle of the steered road wheels to the hand wheel.
  • the hand wheel actuator can be configured for transmitting a shock force, steering torque or the like from the steered road wheels to the hand wheel.
  • the hand wheel actuator comprises an electromotor.
  • the hand wheel actuator comprises a gear for transforming rotational speed of the electromotor.
  • the hand wheel actuator can be externally attached to the steering column stub or integrated into the steering column stub.
  • the behavior of the hand wheel actuator is adjustable, e.g. for different drivers, different driving modes, different driving situations, different environmental conditions or the like. By these means, the steer-by-wire system provides for a realistic driving experience.
  • the steering sensor is configured for sensing the steering angle of the hand wheel. It is preferred that the steering sensor is externally attached to the steering column stub or integrated into the steering column stub. Preferably, the steering sensor is integrated in the hand wheel actuator. Moreover, the steering sensor is further configured for electronically providing the sensed steering angle for the electronic control unit. For transmitting the steering angle of the hand wheel to the steering rack, the road wheel actuator is provided. The road wheel actuator is configured to provide a steering torque to the steering rack, thus transmitting the steering angle to steered road wheels, which are held at the steering rack. Preferably, the road wheel actuator comprises an electromotor. It is further preferred that the road wheel actuator comprises a gear for transforming rotational speed of the electromotor. Preferably, the road wheel actuator is configured to detect a steering angle of the steering rack.
  • the electronic control unit is operable in different modes.
  • the electronic control unit is configured for processing data from the steering angle sensor and the road wheel actuator and for controlling the hand wheel actuator and the road wheel actuator in the operational mode. It is preferred that during normal driving operation of the vehicle, the electronic control unit is in the operational mode.
  • the electronic control unit is configured for saving energy in a sleep mode.
  • the sleep mode can be a mode of the electronic control unit, which will be activated e.g. when the vehicle is parked.
  • the steer-by-wire system comprises the detection device.
  • the detection device is configured to be in a working mode, when the electronic control unit is in a sleep mode.
  • the detection device can be integrated in the electronic control unit.
  • the detection device is configured for detecting a change in an orientation parameter on the vehicle and to activate the electronic control unit from the sleep mode to the operational mode when a detected change in the orientation parameter exceeds a predetermined threshold.
  • An orientation parameter is a parameter, which is related to an orientation of the vehicle or a part of the vehicle with respect to the locomotion of the vehicle. Therefore, the orientation parameter can relate to a change of a steering angle of a road wheel of the vehicle, a turn angle of the road wheel, a steering angle of the hand wheel or the like.
  • a steering angle refers to a direction the vehicle is steered to.
  • a turn angle is directed to a distance the vehicle covers.
  • the orientation parameter can be affected by manually moving the vehicle, e.g. in a vehicle workshop.
  • the predetermined threshold can be set to zero or any value above.
  • a threshold of zero means that any change in an orientation parameter, e.g. vibrations by a passing tram, truck or the like, can cause the detection device to activate the electronic control unit. Therefore, a threshold above zero is preferred.
  • a threshold could be a road wheel turn angle of one degree, a change in steering angle of a half degree or the like.
  • the detection device activates the electronic control unit.
  • the electronic control unit is brought from the sleep mode to the operational mode.
  • the electronic control unit notices this change and keeps the hand wheel synchronized with the steering rack.
  • This synchronization can be performed by operating the hand wheel actuator for adjusting the steering angle of the hand wheel and/or by operating the road wheel actuator respectively or by simply recording the steering angle of the steering rack for a later mutual adaption of the steering angle of the hand wheel and the steering rack, e.g. when the vehicle is brought into the drive mode.
  • a steer-by-wire system has the advantage over conventional steer-by-wire system that in a simple and inexpensive way, the mode of the steer-by-wire system can be automatically changed from a sleep mode to an operational mode without the necessity of manually starting an electronic system of the vehicle. Due to the monitoring of the orientation parameter, the automatic startup of the electronic control unit can be affected by simply moving the vehicle. Thus, handling of the vehicle, especially in a vehicle workshop, can be improved and a synchronization between the hand wheel and the steering rack can be easily kept. Cumbersome synchronization processes are not necessary anymore, since the synchronization is perpetuated.
  • a steer-by-wire system can provide that the detection device is configured for detecting a change in a wheel angle of a road wheel of the vehicle and/or a steering angle of the steering rack as a change in an orientation parameter.
  • the detection device may comprise an angle sensor, an angle speed sensor or the like.
  • the detection device is configured for detecting a change in a steering angle of the hand wheel as a change in an orientation parameter.
  • the detection device may comprise an angle sensor, an angle speed sensor or the like.
  • the electronic control unit is configured to synchronize a steering angle of the hand wheel with a steering angle of the steering rack when being activated by the detection device by selected controlling of the hand wheel actuator and/or the road wheel actuator.
  • the electronic control unit In case the vehicle is in a parking mode and the hand wheel is suddenly moved, an offset steering angle between the hand wheel and the steering rack may occur due a time period the electronic control needs to switch from the sleep mode to the operation mode. To compensate this offset, it is preferred to perform an automated synchronization of the steering angle of the steering rack with the steering angle of the hand wheel.
  • This synchronization can be performed by operating the hand wheel actuator for adjusting the steering angle of the hand wheel and/or by operating the road wheel actuator respectively or by simply recording the steering angle of the steering rack for a later mutual adaption of the steering angle of the hand wheel and the steering rack, e.g. when the vehicle is brought into the drive mode.
  • This has the advantage that in a simple and inexpensive way, it is provided that the hand wheel is always synchronized with the steering rack, especially when the vehicle is brought into the drive mode for driving the vehicle.
  • the detection device is configured to measure a generated electricity of a first electromotor of the road wheel actuator for detecting the orientation parameter.
  • the steering rack will force a rotor of the first electromotor of the road wheel actuator to rotate.
  • the first electromotor will generate electricity.
  • the generated voltage can be sensed by the detection device. If the generated electricity (voltage or current) exceeds the predetermined threshold - in this case a predetermined voltage or current value - the detection device will activate the electronic control unit.
  • the detection device is configured to measure a generated voltage of a second electromotor of the hand wheel actuator for detecting the orientation parameter.
  • the steering rack When the steering angle of the hand wheel is changed, e.g. due manually turning the hand wheel by the driver, the steering rack will force a rotor of the second electromotor of the hand wheel actuator to rotate. Thereby, the second electromotor will generate electricity.
  • the generated voltage can be sensed by the detection device. If the generated electricity (voltage or current) exceeds the predetermined threshold - in this case a predetermined voltage or current value - the detection device will activate the electronic control unit.
  • the detection device is configured to measure a generated voltage of a drive electromotor of the vehicle due to the rotation of a road wheel of the vehicle for detecting the orientation parameter.
  • the drive electromotor is part of a drive system to move the vehicle forwards and backwards.
  • the drive electromotor is mechanically connected to the road wheel or more road wheels, such as two or four, of the vehicle.
  • the electromotor will generate electricity.
  • the generated voltage can be sensed by the detection device. If the generated electricity (voltage or current) exceeds the predetermined threshold - in this case a predetermined voltage or current value - the detection device will activate the electronic control unit.
  • This has the advantage that in a simple and inexpensive way, the overall costs for the steer-by-wire system can be kept comparatively low. By using components, which are normally present in an electrically driven vehicle, there are less additional expensive components necessary. Moreover, the precision and reliability of this detection device is comparatively high.
  • the detection device comprises an angle sensor for detecting an angle of a device of the vehicle as the orientation parameter.
  • the angle sensor can be configured as an angle sensor for sensing a rotational angle of a road wheel of the vehicle, which is mechanically connected to the road wheel actuator. This rotational angle is changeable when the road wheel is rotated, e.g. when the vehicle is pushed forwards or backwards.
  • the angle sensor can be configured to detect a steering angle of the steering rack or the hand wheel.
  • a plurality of angle sensors for detecting different angles can be provided. This has the advantage that in a simple and inexpensive way, the precision and reliability of the detection of the change in orientation parameter can be further improved.
  • the electronic control unit is configured for automatically reentering the sleep mode, when the orientation parameter does not change for a predefined time period.
  • the electronic control unit is configured to switch back to the sleep mode, when the steer-by-wire system does not need to be powered on, e.g. when the workers in the vehicle workshop parked the vehicle at a parking site.
  • the predetermined time period can be e.g. about 30 seconds or 1 minute long.
  • a vehicle comprising a drive system, a brake system and a steer-by-wire system.
  • the steer-by-wire system is configured as a steer-by-wire system according to the first aspect of the invention.
  • the drive system comprises an electromotor for driving the vehicle and for generating electricity.
  • the vehicle according to the invention has all the advantages that have already been described for a steer-by-wire system according to the first aspect of the invention. Accordingly, the vehicle according to the invention has the advantage over conventional vehicles, that in a simple and inexpensive way, the mode of the steer-by- wire system can be automatically changed from a sleep mode to an operational mode without the necessity of manually starting an electronic system of the vehicle. Due to the monitoring of the orientation parameter, the automatic startup of the electronic control unit can be affected by simply moving the vehicle. Thus, handling of the vehicle, especially in a vehicle workshop, can be improved and a synchronization between the hand wheel and the steering rack can be easily kept. Cumbersome synchronization processes are not necessary anymore, since the synchronization is perpetuated.
  • Fig. 1 Shows a steer-by-wire system according to a preferred embodiment of the invention in a schematic top view
  • Fig. 2 Shows a vehicle with a steer-by-wire system according to a preferred embodiment of the invention in a schematic side view.
  • a preferred embodiment of a steer-by-wire system 1 is shown in a schematic top view.
  • the steer-by-wire system 1 comprises a hand wheel 3, fixedly attached to first end of a steering column stub 4.
  • a hand wheel actuator 5 for transmitting a force feedback to the hand wheel 3 is located.
  • the hand wheel actuator 5 comprises an integrated steering angle sensor 7 and a second electromotor 13 for providing the force feedback.
  • the steering angle sensor 7 is also configured as an angle sensor 15 of a detection device 11 to detect a steering angle of the hand wheel 3.
  • steered road wheels 6 are attached to a steering rack 9 of the steer- by-wire system 1 .
  • a road wheel actuator 8 for transmitting the steering angle of the hand wheel 3 to a steering rack 9 is attached.
  • the road wheel actuator 8 comprises a first electromotor 12.
  • two angle sensors 15 of the detection device 11 for sensing angles of components of the steer-by-wire system 1 , are located.
  • One of the angle sensors 15 is configured for detecting a rotational angle of the road wheel 6, the other angle sensor 15 is configured for detecting a steering angle of the steering rack 9.
  • the steer-by-wire system 1 further comprises an electronic control unit 10 for operating the hand wheel actuator 5 and the road wheel actuator 8.
  • the electronic control unit 10 is configured for gathering data from the detection device 11 , the hand wheel actuator 5 and the road wheel actuator 8.
  • a part of the detection device 11 is integrated in the electronic control unit 10 and is configured to activate the electronic control unit 10 from a sleep mode to an operational mode, when a detected orientation parameter of the steer-by-wire system 1 exceeds a predetermined threshold.
  • a drive electromotor 14 is coupled to the detection device 11 that is located within the electronic control unit 10. Thus, electricity generated by the drive electromotor 14 can be detected by the detection device 11 .
  • a preferred embodiment of a vehicle 2 with a steer-by-wire system 1 is illustrated in a schematic side view.
  • the vehicle 2 comprises a drive system 16 with a drive electromotor 14 with a gear box 18 for driving the vehicle 2 and a battery 19 for powering the drive electromotor 14.
  • the vehicle 2 further comprises a brake system 17 for braking road wheels 6 of the vehicle 2.
  • the vehicle 2 comprises a steer-by-wire system 1 , which can be configured as shown in Fig. 1 .

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Transportation (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Mathematical Physics (AREA)
  • Steering Control In Accordance With Driving Conditions (AREA)

Abstract

The present invention relates to a Steer-by-Wire system (1) for a vehicle (2), comprising a hand wheel (3), a steering column stub (4), a hand wheel actuator (5), a steering angle sensor (7), a road wheel actuator (8), a steering rack (9) and an electronic control unit (10). The steer-by-wire system (1) further comprises a detection device (11) for detecting a change in an orientation parameter on the vehicle (2) and to activate the electronic control unit (10) from a sleep mode to the operational mode when a detected change in the orientation parameter exceeds a predetermined threshold. The invention also relates to a vehicle (2) with a steer-by-wire system (1) according to the invention.

Description

Steer-by-Wire system with automatic power on mode
Description
The present invention relates to a steer-by-wire system for a vehicle for a motor vehicle. The invention also relates to a motor vehicle with a generic steer-by-wire system.
For steering a vehicle, a plurality of different steering systems is known. Conventional steering systems comprise a hand wheel for being operated by a driver of a vehicle, a steering rack for transmitting a steering angle to road wheels of the vehicle and a steering column for transmitting the steering angle from the hand wheel to the steering rack. For supporting the driver by reducing a steering torque on the hand wheel, conventional steering systems further comprise steering actuators, such as servo- electronic steering actors.
Due the increasing importance of driver assistance systems, such as parking assistants, collision prevention assistants, autonomous driving assistants or the like, it is advantageous to provide a steering system, which comprises a steering rack without a direct mechanical coupling to the hand wheel. Such steering systems are also known as steer-by-wire steering systems or steer-by-wire systems. The US- parent application US 2022 10212715 A1 discloses an example for a steer-by-wire system with a tilt position adjustment mechanism for tilting a steering column.
Steer-by-wire systems have the advantage over conventional steering systems that a steering angle of the steering rack can be steered without rotating the hand wheel. Furthermore, the hand wheel can be rotated without affecting the steering rack. Thus, unwanted interactions between the driver and the steering rack or the steering wheel and the driver can be avoided, especially during the performance of an automated steering function of the vehicle. The present invention provides a steer-by-wire system for a vehicle with the features of the independent claim 1 and a vehicle with the features of the subordinate claim 10. Further features and details of the invention emerge from the subclaims, the description and the drawings. Features and details that are described in connection with the steer-by-wire system according to the invention naturally also apply in connection with the vehicle according to the invention and vice versa, so that with regard to the disclosure of the individual aspects of the invention, reference is or can always be made to each other.
According to a first aspect of the invention, a steer-by-wire system for a vehicle is provided. The steer-by-wire system comprises a hand wheel for receiving a desired steering angle of a driver of the vehicle, a steering column stub for holding the hand wheel, a hand wheel actuator, connected to the steering column stub for providing a mechanical feedback from steered road wheels of the vehicle to the hand wheel, a steering angle sensor for sensing a steering angle of the hand wheel, a road wheel actuator for transmitting the steering angle of the hand wheel to a steering rack of the steer-by wire system and an electronic control unit for processing data from the steering angle sensor and the road wheel actuator and for controlling the hand wheel actuator and the road wheel actuator in an operational mode. According to the invention, the steer-by-wire system comprises a detection device for detecting a change in an orientation parameter on the vehicle and to activate the electronic control unit from a sleep mode to the operational mode when a detected change in the orientation parameter exceeds a predetermined threshold.
The hand wheel is configured for receiving the desired steering angle of a driver of the vehicle. It is preferred that the hand wheel is configured for being retracted, received by a reception of a dashboard of the vehicle or the like, in order to improve a boarding and disembarking for the driver, to improve the comfort for the driver during an autonomous driving mode of the vehicle or the like. Preferably, the steer-by-wire system is configured for locking the hand wheel, e.g. for keeping the hand wheel in a predetermined position during the autonomous driving mode, in a parking mode or the like. The hand wheel is connected to an upper end of the steering column stub. Thus, the steering column stub is holding the hand wheel. The hand wheel is connected to the steering column stub such that a steering angle of the hand wheel is transmitted to the steering column stub and that a rotational or vibrational movement of the steering column stub is transmitted to the hand wheel. The steering column stub is denoted stub because it is usually shorter than ordinary steering columns of conventional steering systems and does not provide a direct mechanical coupling with the steering rack. The steering column stub is mechanically connected to the hand wheel actuator and the steering sensor.
The hand wheel actuator is configured for providing a mechanical feedback from steered road wheels of the vehicle to the hand wheel. This means that the hand wheel actuator can be configured for transmitting a steering angle of the steered road wheels to the hand wheel. Alternatively or additionally, the hand wheel actuator can be configured for transmitting a shock force, steering torque or the like from the steered road wheels to the hand wheel. Preferably, the hand wheel actuator comprises an electromotor. It is further preferred that the hand wheel actuator comprises a gear for transforming rotational speed of the electromotor. The hand wheel actuator can be externally attached to the steering column stub or integrated into the steering column stub. Preferably, the behavior of the hand wheel actuator is adjustable, e.g. for different drivers, different driving modes, different driving situations, different environmental conditions or the like. By these means, the steer-by-wire system provides for a realistic driving experience.
The steering sensor is configured for sensing the steering angle of the hand wheel. It is preferred that the steering sensor is externally attached to the steering column stub or integrated into the steering column stub. Preferably, the steering sensor is integrated in the hand wheel actuator. Moreover, the steering sensor is further configured for electronically providing the sensed steering angle for the electronic control unit. For transmitting the steering angle of the hand wheel to the steering rack, the road wheel actuator is provided. The road wheel actuator is configured to provide a steering torque to the steering rack, thus transmitting the steering angle to steered road wheels, which are held at the steering rack. Preferably, the road wheel actuator comprises an electromotor. It is further preferred that the road wheel actuator comprises a gear for transforming rotational speed of the electromotor. Preferably, the road wheel actuator is configured to detect a steering angle of the steering rack.
The electronic control unit is operable in different modes. The electronic control unit is configured for processing data from the steering angle sensor and the road wheel actuator and for controlling the hand wheel actuator and the road wheel actuator in the operational mode. It is preferred that during normal driving operation of the vehicle, the electronic control unit is in the operational mode. Preferably, the electronic control unit is configured for saving energy in a sleep mode. The sleep mode can be a mode of the electronic control unit, which will be activated e.g. when the vehicle is parked.
According to the invention, the steer-by-wire system comprises the detection device. Preferably, the detection device is configured to be in a working mode, when the electronic control unit is in a sleep mode. The detection device can be integrated in the electronic control unit. The detection device is configured for detecting a change in an orientation parameter on the vehicle and to activate the electronic control unit from the sleep mode to the operational mode when a detected change in the orientation parameter exceeds a predetermined threshold. An orientation parameter is a parameter, which is related to an orientation of the vehicle or a part of the vehicle with respect to the locomotion of the vehicle. Therefore, the orientation parameter can relate to a change of a steering angle of a road wheel of the vehicle, a turn angle of the road wheel, a steering angle of the hand wheel or the like. A steering angle refers to a direction the vehicle is steered to. A turn angle is directed to a distance the vehicle covers.
The orientation parameter can be affected by manually moving the vehicle, e.g. in a vehicle workshop. The predetermined threshold can be set to zero or any value above. A threshold of zero means that any change in an orientation parameter, e.g. vibrations by a passing tram, truck or the like, can cause the detection device to activate the electronic control unit. Therefore, a threshold above zero is preferred. A threshold could be a road wheel turn angle of one degree, a change in steering angle of a half degree or the like.
When the predetermined threshold is exceeded, the detection device activates the electronic control unit. Thus, the electronic control unit is brought from the sleep mode to the operational mode. When a change of the steering angle of the steering rack occurs, e.g. due to manual moving of the vehicle, since it is now in the operational mode, the electronic control unit notices this change and keeps the hand wheel synchronized with the steering rack. This synchronization can be performed by operating the hand wheel actuator for adjusting the steering angle of the hand wheel and/or by operating the road wheel actuator respectively or by simply recording the steering angle of the steering rack for a later mutual adaption of the steering angle of the hand wheel and the steering rack, e.g. when the vehicle is brought into the drive mode.
A steer-by-wire system according to the invention has the advantage over conventional steer-by-wire system that in a simple and inexpensive way, the mode of the steer-by-wire system can be automatically changed from a sleep mode to an operational mode without the necessity of manually starting an electronic system of the vehicle. Due to the monitoring of the orientation parameter, the automatic startup of the electronic control unit can be affected by simply moving the vehicle. Thus, handling of the vehicle, especially in a vehicle workshop, can be improved and a synchronization between the hand wheel and the steering rack can be easily kept. Cumbersome synchronization processes are not necessary anymore, since the synchronization is perpetuated.
According to a preferred further development of the invention, a steer-by-wire system can provide that the detection device is configured for detecting a change in a wheel angle of a road wheel of the vehicle and/or a steering angle of the steering rack as a change in an orientation parameter. For this purpose, the detection device may comprise an angle sensor, an angle speed sensor or the like. Thus, any change in the position of a road wheel, such as rotational wise and/or directional wise, e.g. due to the deliberate moving of the vehicle by a worker of the vehicle workshop, can be detected and can cause the detection device to activate the electronic control unit, when the respective threshold is exceeded. This has the advantage that in a simple and inexpensive way, the automatic power on of the electronic control unit can be improved.
It is preferred according to the invention that the detection device is configured for detecting a change in a steering angle of the hand wheel as a change in an orientation parameter. It is preferred that, for this purpose, the detection device may comprise an angle sensor, an angle speed sensor or the like. Thus, any change in the steering angle of the hand wheel, e.g. due to the deliberate handling of the hand wheel by a worker of the vehicle workshop, can be detected and can cause the detection device to activate the electronic control unit, when the respective threshold is exceeded. This has the advantage that in a simple and inexpensive way, the automatic power on of the electronic control unit can be improved.
More preferred, the electronic control unit is configured to synchronize a steering angle of the hand wheel with a steering angle of the steering rack when being activated by the detection device by selected controlling of the hand wheel actuator and/or the road wheel actuator. In case the vehicle is in a parking mode and the hand wheel is suddenly moved, an offset steering angle between the hand wheel and the steering rack may occur due a time period the electronic control needs to switch from the sleep mode to the operation mode. To compensate this offset, it is preferred to perform an automated synchronization of the steering angle of the steering rack with the steering angle of the hand wheel. This synchronization can be performed by operating the hand wheel actuator for adjusting the steering angle of the hand wheel and/or by operating the road wheel actuator respectively or by simply recording the steering angle of the steering rack for a later mutual adaption of the steering angle of the hand wheel and the steering rack, e.g. when the vehicle is brought into the drive mode. This has the advantage that in a simple and inexpensive way, it is provided that the hand wheel is always synchronized with the steering rack, especially when the vehicle is brought into the drive mode for driving the vehicle.
In a particularly preferred embodiment of the invention, the detection device is configured to measure a generated electricity of a first electromotor of the road wheel actuator for detecting the orientation parameter. In case the steering angle of the steering rack is changed, e.g. due to the road wheel following a guiding track on the floor, the steering rack will force a rotor of the first electromotor of the road wheel actuator to rotate. Thereby, the first electromotor will generate electricity. The generated voltage can be sensed by the detection device. If the generated electricity (voltage or current) exceeds the predetermined threshold - in this case a predetermined voltage or current value - the detection device will activate the electronic control unit. This has the advantage that in a simple and inexpensive way, the overall costs for the steer-by-wire system can be kept comparatively low. By using components, which are normally present in a steer-by-wire system, there are less additional expensive components necessary. Moreover, the precision and reliability of this detection device is comparatively high.
Preferably, the detection device is configured to measure a generated voltage of a second electromotor of the hand wheel actuator for detecting the orientation parameter. When the steering angle of the hand wheel is changed, e.g. due manually turning the hand wheel by the driver, the steering rack will force a rotor of the second electromotor of the hand wheel actuator to rotate. Thereby, the second electromotor will generate electricity. The generated voltage can be sensed by the detection device. If the generated electricity (voltage or current) exceeds the predetermined threshold - in this case a predetermined voltage or current value - the detection device will activate the electronic control unit. This has the advantage that in a simple and inexpensive way, the overall costs for the steer-by-wire system can be kept comparatively low. By using components, which are normally present in a steer-by- wire system, there are less additional expensive components necessary. Moreover, the precision and reliability of this detection device is comparatively high. According to a preferred embodiment of the invention, the detection device is configured to measure a generated voltage of a drive electromotor of the vehicle due to the rotation of a road wheel of the vehicle for detecting the orientation parameter. The drive electromotor is part of a drive system to move the vehicle forwards and backwards. The drive electromotor is mechanically connected to the road wheel or more road wheels, such as two or four, of the vehicle. When the vehicle is moved forwards or backwards, e.g. due manually pushing the vehicle in a desired direction, the road wheel of the vehicle will force a rotor of the drive electromotor to rotate. Thereby, the electromotor will generate electricity. The generated voltage can be sensed by the detection device. If the generated electricity (voltage or current) exceeds the predetermined threshold - in this case a predetermined voltage or current value - the detection device will activate the electronic control unit. This has the advantage that in a simple and inexpensive way, the overall costs for the steer-by-wire system can be kept comparatively low. By using components, which are normally present in an electrically driven vehicle, there are less additional expensive components necessary. Moreover, the precision and reliability of this detection device is comparatively high.
Particularly preferred, the detection device comprises an angle sensor for detecting an angle of a device of the vehicle as the orientation parameter. The angle sensor can be configured as an angle sensor for sensing a rotational angle of a road wheel of the vehicle, which is mechanically connected to the road wheel actuator. This rotational angle is changeable when the road wheel is rotated, e.g. when the vehicle is pushed forwards or backwards. Alternatively, the angle sensor can be configured to detect a steering angle of the steering rack or the hand wheel. According to the invention, a plurality of angle sensors for detecting different angles can be provided. This has the advantage that in a simple and inexpensive way, the precision and reliability of the detection of the change in orientation parameter can be further improved.
It is preferred, according to the invention, that the electronic control unit is configured for automatically reentering the sleep mode, when the orientation parameter does not change for a predefined time period. In other words, when the electronic control unit is brought into the operational mode by the detection device, the energy consumption of the steer-by-wire system is increased compared to the sleep mode. To avoid excess energy waste, the electronic control unit is configured to switch back to the sleep mode, when the steer-by-wire system does not need to be powered on, e.g. when the workers in the vehicle workshop parked the vehicle at a parking site. The predetermined time period can be e.g. about 30 seconds or 1 minute long. After this time period, there is a reasonable likeliness that the vehicle will not be moved for a certain time and a sleep mode is advantageous for saving energy. This has the advantage that in a simple and inexpensive way, the energy consumption of the steer- by-wire system can be reduced.
According to a second aspect of the invention, a vehicle is provided. The vehicle comprises a drive system, a brake system and a steer-by-wire system. According to the invention, the steer-by-wire system is configured as a steer-by-wire system according to the first aspect of the invention. Preferably, the drive system comprises an electromotor for driving the vehicle and for generating electricity.
The vehicle according to the invention has all the advantages that have already been described for a steer-by-wire system according to the first aspect of the invention. Accordingly, the vehicle according to the invention has the advantage over conventional vehicles, that in a simple and inexpensive way, the mode of the steer-by- wire system can be automatically changed from a sleep mode to an operational mode without the necessity of manually starting an electronic system of the vehicle. Due to the monitoring of the orientation parameter, the automatic startup of the electronic control unit can be affected by simply moving the vehicle. Thus, handling of the vehicle, especially in a vehicle workshop, can be improved and a synchronization between the hand wheel and the steering rack can be easily kept. Cumbersome synchronization processes are not necessary anymore, since the synchronization is perpetuated. Further advantages, features and details of the invention unfold from the following description, in which by reference to drawings working examples of the present invention are described in detail. Thereby, the features from the claims as well as the features mentioned in the description can be essential for the invention as taken alone or in an arbitrary combination. In the drawings:
Fig. 1 Shows a steer-by-wire system according to a preferred embodiment of the invention in a schematic top view, and
Fig. 2 Shows a vehicle with a steer-by-wire system according to a preferred embodiment of the invention in a schematic side view.
In Fig. 1 , a preferred embodiment of a steer-by-wire system 1 according to the invention is shown in a schematic top view. The steer-by-wire system 1 comprises a hand wheel 3, fixedly attached to first end of a steering column stub 4. At a second end of the steering column stub 4, a hand wheel actuator 5 for transmitting a force feedback to the hand wheel 3 is located. The hand wheel actuator 5 comprises an integrated steering angle sensor 7 and a second electromotor 13 for providing the force feedback. The steering angle sensor 7 is also configured as an angle sensor 15 of a detection device 11 to detect a steering angle of the hand wheel 3.
In this drawing, steered road wheels 6 are attached to a steering rack 9 of the steer- by-wire system 1 . At the steering rack 9, a road wheel actuator 8 for transmitting the steering angle of the hand wheel 3 to a steering rack 9 is attached. For providing the necessary force, the road wheel actuator 8 comprises a first electromotor 12. At the steering rack 9, two angle sensors 15 of the detection device 11 for sensing angles of components of the steer-by-wire system 1 , are located. One of the angle sensors 15 is configured for detecting a rotational angle of the road wheel 6, the other angle sensor 15 is configured for detecting a steering angle of the steering rack 9.
The steer-by-wire system 1 further comprises an electronic control unit 10 for operating the hand wheel actuator 5 and the road wheel actuator 8. Moreover, the electronic control unit 10 is configured for gathering data from the detection device 11 , the hand wheel actuator 5 and the road wheel actuator 8. A part of the detection device 11 is integrated in the electronic control unit 10 and is configured to activate the electronic control unit 10 from a sleep mode to an operational mode, when a detected orientation parameter of the steer-by-wire system 1 exceeds a predetermined threshold. Furthermore, a drive electromotor 14 is coupled to the detection device 11 that is located within the electronic control unit 10. Thus, electricity generated by the drive electromotor 14 can be detected by the detection device 11 .
In Fig. 2 , a preferred embodiment of a vehicle 2 with a steer-by-wire system 1 according to of the invention is illustrated in a schematic side view. The vehicle 2 comprises a drive system 16 with a drive electromotor 14 with a gear box 18 for driving the vehicle 2 and a battery 19 for powering the drive electromotor 14. The vehicle 2 further comprises a brake system 17 for braking road wheels 6 of the vehicle 2. Furthermore, the vehicle 2 comprises a steer-by-wire system 1 , which can be configured as shown in Fig. 1 .
List of reference signs
1 steer-by-wire system
2 vehicle
3 hand wheel
4 steering column stub
5 hand wheel actuator
6 road wheel
7 steering angle sensor
8 road wheel actuator
9 steering rack
10 electronic control unit
11 detection device
12 first electromotor
13 second electromotor
14 drive electromotor
15 angle sensor
16 drive system
17 brake system
18 gear box
19 battery

Claims

Patent claims
1 . Steer-by-Wire system (1 ) for a vehicle (2), comprising a hand wheel (3) for receiving a desired steering angle of a driver of the vehicle (2), a steering column stub (4) for holding the hand wheel (3), a hand wheel actuator (5), connected to the steering column stub (4) for providing a mechanical feedback from steered road wheels (6) of the vehicle (2) to the hand wheel (3), a steering angle sensor (7) for sensing a steering angle of the hand wheel (3), a road wheel actuator (8) for transmitting the steering angle of the hand wheel (3) to a steering rack (9) of the steer-by wire system (1 ) and an electronic control unit (10) for processing data from the steering angle sensor (7) and the road wheel actuator (8) and for controlling the hand wheel actuator (5) and the road wheel actuator (8) in an operational mode, characterized in that the steer-by-wire system (1 ) comprises a detection device (11 ) for detecting a change in an orientation parameter on the vehicle (2) and to activate the electronic control unit (10) from a sleep mode to the operational mode when a detected change in the orientation parameter exceeds a predetermined threshold.
2. Steer-by-wire system (1 ) according to claim 1 , characterized in that the detection device (11 ) is configured for detecting a change in a wheel angle of a road wheel (6) of the vehicle (2) and/or a steering angle of the steering rack (9) as a change in an orientation parameter.
3. Steer-by-wire system (1 ) according to claim 1 or 2, characterized in that the detection device (11 ) is configured for detecting a change in a steering angle of the hand wheel (3) as a change in an orientation parameter. Steer-by-wire system (1 ) according to any of the previous claims, characterized in that the electronic control unit (10) is configured to synchronize a steering angle of the hand wheel (3) with a steering angle of the steering rack (9) when being activated by the detection device (11 ) by selected controlling of the hand wheel actuator (5) and/or the road wheel actuator (8). Steer-by-wire system (1 ) according to any of the previous claims, characterized in that the detection device (11 ) is configured to measure a generated electricity of a first electromotor (12) of the road wheel actuator (8) for detecting the orientation parameter. Steer-by-wire system (1 ) according to any of the previous claims, characterized in that the detection device (11 ) is configured to measure a generated voltage of a second electromotor (13) of the hand wheel actuator (5) for detecting the orientation parameter. Steer-by-wire system (1 ) according to any of the previous claims, characterized in that the detection device (11 ) is configured to measure a generated voltage of a drive electromotor (14) of the vehicle (2) due to the rotation of a road wheel (6) of the vehicle (2) for detecting the orientation parameter. Steer-by-wire system (1 ) according to any of the previous claims, characterized in that the detection device (11 ) comprises an angle sensor (15) for detecting an angle of a device of the vehicle (2) as the orientation parameter. Steer-by-wire system (1 ) according to any of the previous claims, characterized in that the electronic control unit (10) is configured for automatically reentering the sleep mode, when the orientation parameter does not change for a predefined time period. Vehicle (2), comprising a drive system (16), a brake system (17) and a steer- by-wire system (1 ), characterized in that the steer-by-wire system (1 ) is configured as a steer-by-wire system (1 ) according to any of the previous claims.
PCT/EP2022/076006 2022-07-19 2022-09-20 Steer-by-wire system with automatic power on mode WO2024017488A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE102022118034 2022-07-19
DE102022118034.4 2022-07-19

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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2891233A1 (en) * 2005-09-24 2007-03-30 Zf Lenksysteme Gmbh Motor vehicle steering system has servomotor to regulate wheel lock angle and sensor to monitor its shaft rotation
EP2037221A2 (en) * 2007-09-13 2009-03-18 Marquardt GmbH Rotation angle sensor
WO2019052651A1 (en) * 2017-09-15 2019-03-21 Thyssenkrupp Presta Ag Actuator synchronization in a steer-by-wire steering system
WO2019068306A1 (en) * 2017-10-02 2019-04-11 Thyssenkrupp Presta Ag Steer-by-wire steering system with a feedback actuator having redundant sleep-mode rotor position sensors
US20220212715A1 (en) 2019-04-18 2022-07-07 Nsk Ltd. Steering device

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2891233A1 (en) * 2005-09-24 2007-03-30 Zf Lenksysteme Gmbh Motor vehicle steering system has servomotor to regulate wheel lock angle and sensor to monitor its shaft rotation
EP2037221A2 (en) * 2007-09-13 2009-03-18 Marquardt GmbH Rotation angle sensor
WO2019052651A1 (en) * 2017-09-15 2019-03-21 Thyssenkrupp Presta Ag Actuator synchronization in a steer-by-wire steering system
WO2019068306A1 (en) * 2017-10-02 2019-04-11 Thyssenkrupp Presta Ag Steer-by-wire steering system with a feedback actuator having redundant sleep-mode rotor position sensors
US20220212715A1 (en) 2019-04-18 2022-07-07 Nsk Ltd. Steering device

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