Steering system design and vehicle with a steering system design

Abstract

Steering system assembly (100) for a vehicle (F), preferably a steer-by-wire system, in which in particular detection devices (11, 21, 31) and conversion devices (13, 23, 33) for a steering request are mechanically decoupled from each other, comprising: - a first steering system (10) for providing a steering function, which is autonomously designed and / or has a first power supply (E1), - a second steering system (20) to provide a first fallback level for the steering function, which is autonomously designed and / or has a second power supply (E2), - and a third steering system (30) for providing a second fallback level for the steering function, in particular by means of wheel-selective braking, characterized in that a control unit (101) is provided, wherein the control unit (101) is designed to - Diagnostic data (D1) from the first steering system (10), - Diagnostic data (D2) from the second steering system (20), - Diagnostic data (D3) from the third steering system (30), - Diagnostic data (DE1) from the first power supply (E1), - Diagnostic data (DE2) from the second power supply (E2), - Diagnostic data (DE3) from a third power supply (E2), - at least one operating parameter (BP) of the vehicle (F) and - to query, receive and / or process at least one environment parameter (UP).

Description

[0001] The invention relates to a steering system structure for a vehicle having the features of the preamble of claim 1, in particular a steer-by-wire system in which, in particular, detection devices and implementation devices for a steering request are mechanically decoupled from one another. Furthermore, the invention relates to a vehicle with a corresponding steering system structure.

[0002] Steer-by-wire systems are generally well-known. Steer-by-wire systems can provide several advantages for both conventional vehicles and automated (Level 4 according to the SAE definition) to autonomous (Level 5 according to the SAE definition) vehicles.

[0003] For automated vehicles, steer-by-wire systems can enable the steering wheel to be folded away and / or retracted. This creates more space for the driver, who becomes a passenger during the fully automated journey, to engage in activities such as sleeping, reading the newspaper, surfing the internet, etc. Furthermore, folding and retracting the steering wheel enables new interior concepts, such as rotating seats and fold-out tables. Furthermore, the mechanical decoupling between the steering wheel and the steering actuator prevents unintentional misoperation during fully automated driving: Even if the steering wheel were not folded away and / or retracted, accidental contact with the steering wheel during fully automated driving (e.g., the driver is asleep) would not result in an unwanted vehicle reaction. Autonomous vehicles do not require a driver, so a steer-by-wire system is essential.

[0004] In conventional vehicles, steer-by-wire systems can facilitate entry and exit by folding and / or retracting the steering wheel. A variable ratio between the steering wheel angle and the steering angle at the wheels, adjusted to the vehicle speed, means that when parking or maneuvering, only a small amount of steering is required to achieve the large steering angles required in these situations. With a steer-by-wire system with a so-called "force feedback actuator," the haptic feedback to the driver can be adjusted to be softer or harder, sporty or comfortable, direct or dampened. These settings can be transferred from vehicle to vehicle for individual driver preference.

[0005] In addition, the vehicles can be easily adapted for people with disabilities. For people with a physical disability that makes operating the steering wheel difficult or impossible, by-wire steering systems can be installed as standard, offering alternative operating concepts without the need for complex vehicle modifications.

[0006] With steer-by-wire systems, the driver's mechanical fallback function is eliminated. A fallback function can be provided to enable continued driving in a degraded driving mode (e.g., reduced speed) and / or limited driving mode (e.g., only for a limited time or a limited distance) after an initial fault.

[0007] The disadvantage of known systems is that after a second fault and / or after the primary steering system and the secondary steering system fail, continued driving and safety in the operation of the vehicle can no longer be guaranteed.

[0008] Examples of steer-by-wire systems are shown in the documents DE 10 2019 007 715 A1, US 2002 / 0 189 889 A1 and JP 2017- 077832 A.

[0009] The object of the invention is therefore to provide an improved steering system structure for a vehicle, in particular a steer-by-wire system, in which, in particular, detection devices and implementation devices for a steering request are mechanically decoupled from one another. In particular, the object of the invention is to provide such a steering system structure for a vehicle, in particular such a steer-by-wire system, which enables increased safety in the operation of the vehicle and which creates improved customer comfort. Furthermore, the object of the invention is to provide an improved vehicle with a corresponding steering system structure.

[0010] The object of the invention is achieved by: a steering system structure for a vehicle, in particular a steer-by-wire system, in which detection devices and implementation devices for a steering request are preferably mechanically decoupled from one another, with the features of the independent device claim, in particular from the characterizing part. Furthermore, the object is achieved by a corresponding vehicle with the features of the independent device claim. Advantageous further developments are the subject of the subclaims. Features that are described in connection with individual aspects and / or embodiments of the invention naturally also apply in connection with the other aspects and / or embodiments, and vice versa, so that with regard to the disclosure, reciprocal reference is or can always be made to the individual aspects of the invention and / or embodiments.

[0011] The invention provides a steering system assembly, a so-called steer-by-wire system, for a vehicle, e.g., a hybrid or electric vehicle, e.g., an automated (Level 4 according to the SAE definition) to autonomous (Level 5 according to the SAE definition) vehicle. In the steering system assembly, detection devices and implementation devices for a steering command (which can come, for example, from the driver or the vehicle) can advantageously be mechanically decoupled from each other. The steering system assembly comprises the following subsystems: - a first (or primary) steering system (so-called autonomous steering system) for providing a steering function, which is autonomous and / or has a first (or primary) energy supply, - a second (or secondary) steering system (so-called autonomous steering system) for providing a first fallback level for the steering function, which is autonomous and / or has a second (or secondary) power supply, - and a third steering system (at least partially indirect and / or functionally implemented steering system) for providing a second fallback level for the steering function, in particular by wheel-selective, possibly pulsed, braking (preferably by wheel-selective, possibly pulsed, braking interventions).

[0012] The vehicle in which the steering system structure according to the invention can be used can, for example, have a braking system, preferably a brake-by-wire system, in which detection devices and implementation devices for a braking request (which can come, for example, from the driver or from the vehicle) can advantageously be mechanically decoupled from one another. Furthermore, the vehicle can have at least one central control unit. Furthermore, the vehicle can have a driver-vehicle interface, for example in the form of an interactive input and output unit, e.g., comprising a display, an acoustic output device, etc.

[0013] The vehicle in which the steering system structure according to the invention can be used can preferably be designed as a fully automated vehicle (Level 4 according to SAE definition) or an autonomously driving vehicle (Level 5 according to SAE definition).

[0014] If the driver is in control, the steering command can come from the driver, for example, by applying an electronic brake pedal. If the vehicle is in control, the steering command comes from the vehicle.

[0015] In a fully automated vehicle (Level 4 according to the SAE definition), the driver can become a passenger or user of the vehicle. A fully automated vehicle can feature a driver-vehicle interface. In an autonomous vehicle (Level 5 according to the SAE definition), there is no driver. Only users are provided. An autonomous vehicle can feature a user-vehicle interface.

[0016] The concept of the invention lies in the fact that the steering system structure provides two redundant autonomous steering systems that are designed to be self-sufficient or independent and can function independently of each other and of other functional systems of the vehicle. The first and second autonomous steering systems can be supplied with electrical energy via two independent power supplies, the first and second power supplies. The independent power supplies can, for example, each have a high-voltage battery that can be operated with direct voltages of approximately 60 V to approximately 1.5 kV. Furthermore, the independent power supplies can each have a suitable DC / DC converter.

[0017] Each of these two steering systems can also have multiple subsystems, such as a steering request detector (or detector device for detecting the steering request) and a steering request conversion device (or conversion device for converting the steering request). In both autonomous steering systems, the steering request can be transmitted from the respective detector to the respective conversion device via a corresponding transmission system, such as a bus system or a data bus, e.g., using a CAN or SENT protocol.

[0018] The respective steering request detection system can be implemented as a steering column module. The driver's steering wheel operation can be detected via steering wheel angle sensors on the steering wheel. Control electronics for the respective steering request detection system, comprising, for example, corresponding electronics and / or software, can passively receive the sensor data, actively query it, and, if necessary, evaluate it. Furthermore, the control electronics for the respective steering request detection system can transmit the sensor data and / or the evaluation results to the corresponding steering request implementation system via an associated transmission system. The respective steering request implementation system can also have control electronics, comprising, for example, corresponding electronics and / or software.The evaluation of sensor data from the respective steering request detection can be performed in the control electronics of the steering request detection and / or in the control electronics of the steering request implementation. The control electronics of the steering request detection and the control electronics of the steering request implementation can be provided as separate control electronics or as a single control electronics unit.

[0019] The respective steering request implementation can be implemented as a steering gear, which can be installed, for example, on a vehicle axle, e.g., the front axle. Control electronics of the steering request implementation, comprising, for example, appropriate electronics and / or software, can control an electric motor and a steering gear to implement the detected steering request. Sensors can be provided on the vehicle axle, e.g., the front axle, which monitor the control, in particular the implemented steering request. The control electronics and the sensors can be connected to one another via a data line. The control electronics advantageously implements the steering request taking sensor data into account.

[0020] In addition to the first and second autonomous steering systems, which can have their own long-term energy supplies, a short-term energy supply can also be provided. The third steering system uses wheel-selective braking and the respective control unit of the first and / or second braking system. The high-voltage battery, in particular the traction battery, feeds the first energy supply and the second energy supply. The first braking system is connected to the first energy supply and to the short-term energy supply. The second braking system is connected to the second energy supply. The short-term energy supply can represent part of the third steering system. The respective long-term energy supply can, for example, be provided via a DC / DC converter, which can be connected to a corresponding high-voltage battery. The short-term energy supply can, for example, be provided via a low-voltage battery and / or a supercapacitor, so-called.Ultra-Cap, or similar. The operating voltage of the low-voltage battery can be between 12 V and 14 V.

[0021] Furthermore, the inventive concept is that the third steering system can be provided at least partially as an indirect or dependent and / or functionally implemented or indirect steering system for providing a second fallback level for the steering function, for example, via another functionally essential system of the vehicle, such as a braking system, for example through wheel-selective, possibly pulsed, braking. The braking system acts as a third steering request implementation (or implementation device for implementing the steering request).

[0022] The third steering system can advantageously include a third steering request detection system. The third steering request detection system can be implemented, for example, via a third steering wheel angle sensor. Alternatively or additionally, the third steering request detection system can utilize a driver assistance system, e.g., a lane departure warning system, lane recognition, an autopilot, etc. The third steering request detection system can be connected directly to a control unit via a signal line. The control unit can control the first, second, or third steering request implementation system. In the event of a critical error, the vehicle can be automatically steered to the side of the road. If steering is not possible, the vehicle can be decelerated and / or braked, preferably to a standstill, e.g., in the center of the lane.

[0023] The steering system assembly may have its own control unit, which may communicate with a central control unit of the vehicle. Furthermore, it is conceivable that the steering system assembly may have its own control unit, which may be integrated into the central control unit of the vehicle via software and / or hardware.

[0024] Since the subsystems have multiple components, the failure of one of these components can lead to the failure of the respective subsystem. Failure of the primary or secondary steering request sensing can be caused, for example, by a failure of electronics, a sensor, or software. Failure of the primary or secondary steering request implementation can be caused, for example, by a failure of electronics, a sensor, software, or an electric motor. Failure of the primary or secondary power supply can be caused, for example, by a failure of a power line, a battery, a DC / DC converter, a fuse, an electronic component, or software. Failure of a data bus, for example the failure of the data bus between steering request sensing and steering request implementation, can also lead to the failure of the primary or secondary steering system.

[0025] The control unit can receive diagnostic messages, "alive" signals, and / or error states from the first and second autonomous steering systems, as well as from the third indirect steering system, as well as from the first and second power supplies and from the third power supply, for example via a suitable transmission system, such as a bus system or a data bus, e.g., with a CAN or SENT protocol, e.g., via a CAN bus, and / or a wireless transmission, such as a radio transmission. Furthermore, the control unit can receive operating parameters of the vehicle, such as speed, load status, etc. In addition, the control unit can receive environmental parameters, such as, in particular, road conditions (snow, ice, degree of wetness, dryness, coefficient of friction), temperature, humidity, etc.

[0026] Based on these input signals (diagnostic messages and / or error states, vehicle operating parameters and / or environmental parameters), the control unit can decide whether steering via wheel-selective brake pulses is possible, and / or whether the vehicle can continue driving after a first or second error in the steering systems or in the energy supplies, and / or whether steering to the edge of the road is possible, and / or whether automatic deceleration to a standstill is necessary, and / or whether, following a failure of the primary and secondary steering request detection, this should be carried out based on the third steering request detection.

[0027] The control unit can request steering via wheel-selective brake pulses and / or deceleration and / or braking of the vehicle from the brake system control unit. The control unit can send the steering request to the brake system control unit if necessary.

[0028] The steering system assembly control unit and the braking system control unit may be provided as a common unit or as two separate control units.

[0029] The control unit can also control the driver-vehicle interface control unit to inform and / or warn the driver about the errors and / or to provide a suggestion for further operation of the vehicle, such as visiting a workshop. Furthermore, the control unit can inform the driver about the remaining distance and / or the remaining driving time.

[0030] The following describes several exemplary fault scenarios that demonstrate the advantages of the steering system design according to the invention following a simple fault in one of the steering systems. The advantages lie in particular in the fact that the vehicle can continue to drive. Continuing the vehicle's drive after a simple fault is possible because, after a simple fault, two options are still available for continuing to operate the vehicle, for example, detecting and implementing a driver's steering command. • A relevant fault scenario is the failure of the primary or secondary steering prompt detection. In this case, redundant detection of the steering prompt is still ensured via the remaining secondary or primary steering prompt detection and the third steering prompt detection. The vehicle can continue driving, at least to a limited extent, e.g., for a specific time and / or distance. The driver can be informed of this via the driver-vehicle interface. • Another relevant error scenario is the failure of the primary or secondary steering request implementation when steering via wheel-selective braking pulses is simultaneously possible. The control unit uses vehicle and road condition data to check whether steering via wheel-selective braking pulses is possible. In this error scenario, redundant implementation of the steering request is still ensured via the remaining secondary or primary steering request implementation as well as via steering via wheel-selective braking pulses. The vehicle can continue to drive, at least to a limited extent, e.g., for a specific time and / or distance. The driver can be informed of this via the driver-vehicle interface. • Another relevant fault scenario is the failure of the first or second long-term energy supply for the first or second steering system. If the first long-term energy supply fails, the energy supply to the first steering system continues to be ensured for a short time via the third energy supply, and the energy supply to the secondary steering system continues to be ensured via the second long-term energy supply. If the second long-term energy supply fails, the energy supply to the first steering system continues to be ensured via the first long-term energy supply and for a short time via the third energy supply. The vehicle can continue to drive, at least to a limited extent, e.g., for a specific time and / or distance. The driver can be informed of this via the driver-vehicle interface.

[0031] The following describes several exemplary fault scenarios that demonstrate the advantages of the steering system design according to the invention following a double fault in one of the steering systems. The advantages lie in the fact that, after a double fault, the vehicle can be decelerated to a safe state, ideally to a standstill, by wheel-selective braking and / or automatic braking. This is possible after a double fault because, after a double fault, at least one opportunity is still available to detect and implement the steering command and / or to decelerate the vehicle automatically and / or based on a braking command. • A relevant fault case is the simultaneous failure of the primary and secondary steering systems when steering via wheel-selective brake pulses is possible at the same time. The control unit checks whether steering via wheel-selective brake pulses is possible using vehicle and road condition data. In this fault case, the steering request is implemented via the remaining third steering request implementation, in particular via wheel-selective brake pulses. To do this, the control unit requests steering via wheel-selective brake pulses from the control unit of the braking system and sends the steering request to the control unit of the braking system. The control unit of the braking system then controls the braking system appropriately, advantageously using vehicle and road condition data. Furthermore, the control unit can request automatic deceleration and / or emergency braking to a standstill from the braking system.The driver can be informed and / or warned about this via the driver-vehicle interface. • Another relevant fault scenario is the simultaneous failure of the first and second power supplies for the first and second steering systems. In this case, the power supply to the control unit and the first steering system is briefly ensured by the third power supply. In this case, the control unit requests immediate deceleration and / or emergency braking to a standstill from the braking system. The driver can be informed and / or warned of this via the driver-vehicle interface. • A relevant error is the failure of either the primary or secondary steering request implementation, if at the same time steering the vehicle via wheel-selective braking pulses is not or no longer possible. "No longer possible" means: While driving, the vehicle or road conditions change in such a way that steering via wheel-selective braking pulses is no longer possible. The control unit detects whether steering the vehicle via wheel-selective braking pulses is possible depending on the vehicle and road conditions. Possible reasons for preventing steering the vehicle via wheel-selective braking pulses include: ◯ Vehicle speed is too low, and / or ◯ Friction coefficient between tire and road surface is too low.

[0032] In this event, the control unit requests automatic deceleration and / or emergency braking to a standstill from the braking system control unit. The driver can be informed and / or warned of this via the driver-vehicle interface. • Another relevant error scenario is the failure of the primary or secondary steering request detection. If a third steering request detection is not possible because no third steering wheel angle sensor is installed, and automatic steering with the help of a driver assistance system is also not possible, the control unit requests automatic deceleration and / or emergency braking to a standstill from the brake system control unit. The driver can be informed and / or warned of this via the driver-vehicle interface.

[0033] As already indicated above, it can be advantageous if the third steering system can be implemented, at least in part, functionally by another essential system of the vehicle, in particular by a braking system and / or a driver assistance system. In this way, existing resources in the vehicle can be used to provide a second fallback level for providing the braking function. The first or primary steering system normally provides the steering function. The first fallback level for providing the steering function is created by the second or secondary steering system. The second fallback level is created by the third (at least partially indirect) steering system functionally or indirectly via another essential system of the vehicle.

[0034] Advantageously, the third steering system can be designed to provide the steering function through wheel-selective braking. In this way, a braking system of the vehicle can be advantageously used not only for braking / deceleration, but also for steering the vehicle. The braking system can thus serve as a third implementation device for implementing the steering request.

[0035] Furthermore, it may be advantageous if the third steering system can have a third detection device for detecting the steering request. In this way, the third (at least partially indirect) steering system can provide both steering request detection (or detection device for detecting the steering request) and steering request implementation (or implementation device for implementing the steering request). The detection device for detecting the steering request in the third steering system is the third detection device. The implementation device for implementing the steering request in the third steering system can preferably be a braking system of the vehicle.

[0036] Advantageously, the third detection device can comprise a third steering wheel angle sensor for detecting the steering request. In this way, a further fallback level for detecting the steering request can be provided simply and cost-effectively.

[0037] Furthermore, the third detection device can be implemented at least partially functionally by another functionally essential system of the vehicle, in particular by a driver assistance system, preferably a lane departure warning system, an autopilot, etc. In this way, a further fallback level for detecting the steering request can be provided by existing resources in the vehicle.

[0038] Furthermore, it can be provided that the third detection device has a third transmission system for forwarding the detected steering request to a control unit. Furthermore, a first signal line can be provided, which is designed to forward the detected steering request from the control unit to the first steering system. Furthermore, a second signal line can be provided, which is designed to forward the detected steering request from the control unit to the second steering system. In this way, the control unit can receive the steering request in the second fallback level.

[0039] Furthermore, a third power supply can be provided at least for the first steering system. The third power supply can preferably be designed to supply a control unit. It is conceivable that the third power supply can be designed as a short-term power supply, in particular comprising a low-voltage battery and / or a supercapacitor. Thus, in the steering system design, three power supplies—two long-term power supplies and one short-term power supply—can be provided to enable steering of the vehicle in the event of a single fault or even a double fault in one of the power supplies.

[0040] As already indicated above, the first steering system or the primary steering system can be designed autonomously and operate independently and autonomously from other systems in the vehicle. For this purpose, the first steering system can have a first detection device for detecting the steering request, a first conversion device for converting the steering request, and / or a first transmission system for forwarding the detected steering request from the first detection device to the first conversion device. Furthermore, the first steering system can have at least one control electronics unit for a first detection device, a first conversion device, and a first transmission system.

[0041] As also indicated above, the second steering system or the secondary steering system can also be designed autonomously and operate independently and autonomously from other systems in the vehicle. For this purpose, the second steering system can have a second detection device for detecting the steering request, a second conversion device for converting the steering request, and / or a second transmission system for forwarding the detected steering request from the second detection device to the second conversion device. Furthermore, the second steering system can have at least one control electronics system for a second detection device, a second conversion device, and a second transmission system.

[0042] Advantageously, the first power supply can be designed as a long-term power supply, for example, comprising a high-voltage battery and / or a DC / DC converter. According to a further advantage, the second power supply can be designed as a long-term power supply, for example, comprising a high-voltage battery and / or a DC / DC converter.

[0043] Furthermore, it is conceivable that the first power supply and / or the second power supply can be designed to supply a control unit. In this way, the first power supply and / or the second power supply can be used across multiple functions.

[0044] Furthermore, it is conceivable that the first steering system can be connected to a control unit in terms of signaling, for example via a transmission system such as a bus system, for example for transmitting diagnostic data.

[0045] Furthermore, it is conceivable that the first steering system is connected in terms of control technology, for example via a transmission system, such as a bus system, to a control unit for executing a steering request which was detected in particular by a third detection device.

[0046] But the second steering system can also be connected to a control unit via a signal transmission system, such as a bus system, for example for transmitting diagnostic data.

[0047] Furthermore, the second steering system can be connected in terms of control technology, for example via a transmission system, such as a bus system, to a control unit for executing a steering request which was detected in particular by a third detection device.

[0048] Advantageously, the first power supply can be connected to a control unit via a signal transmission system, such as a bus system, for example for transmitting diagnostic data.

[0049] Furthermore, it may be advantageous for the second power supply to be connected to a control unit in terms of signaling, for example via a transmission system such as a bus system, for example for transmitting diagnostic data.

[0050] A control unit is provided in the steering system structure.

[0051] The control unit can, for example, be integrated into a central control unit of the vehicle, either in software or hardware. Alternatively, it is conceivable that the control unit could be provided as a separate control unit.

[0052] The control unit is designed to - Diagnostic data from the first steering system, - Diagnostic data from the second steering system, - Diagnostic data from the third steering system, - Diagnostic data from the first power supply, - Diagnostic data from the second power supply, - Diagnostic data from a third power supply, and / or - at least one operating parameter of the vehicle, in particular speed, load condition, etc., and / or - to query, receive and / or process at least one environmental parameter, in particular road condition, friction coefficient, temperature, humidity, etc.

[0053] In this way, the control unit can decide whether the steering systems are functional, whether there is a fault, whether there is a double fault and / or whether wheel-selective braking of the vehicle is possible.

[0054] Furthermore, the control unit can be designed to - to control the first steering system and / or the second steering system to execute the steering request.

[0055] The control can preferably be carried out as a function of diagnostic data from the first steering system, from the second steering system, from the third steering system, from the first energy supply, from the second energy supply, from the third energy supply, at least one operating parameter of the vehicle, in particular speed, load condition, etc., and / or at least one environmental parameter, in particular road condition, coefficient of friction, temperature, humidity, etc.

[0056] Furthermore, the control unit can be designed to - to control another functionally essential system of the vehicle, in particular a braking system, in order to provide the steering function by wheel-selective braking.

[0057] The control can preferably be carried out as a function of diagnostic data from the first steering system, from the second steering system, from the third steering system, from the first energy supply, from the second energy supply, from the third energy supply, at least one operating parameter of the vehicle, in particular speed, load condition, etc., and / or at least one environmental parameter, in particular road condition, coefficient of friction, temperature, humidity, etc.

[0058] In addition, the control unit can be designed to - to control a driver-vehicle interface to inform and / or warn a driver about errors and / or to provide a suggestion for further operation of the vehicle, such as visiting a workshop. In an autonomous vehicle, the driver-vehicle interface can be referred to as a user-vehicle interface or a passenger-vehicle interface.

[0059] In addition, the control unit can be designed to - to inform a driver about the remaining distance and / or the remaining travel time.

[0060] The braking system or brake-by-wire system, which is used for wheel-selective braking, can have: - a first braking system for providing a braking function, which is autonomous and / or has the first energy supply, - a second braking system for providing a first fallback level for the braking function, which is autonomous and / or has the second energy supply, - and a third braking system for providing a second fallback level for the braking function, in particular by means of a generator-based deceleration.

[0061] The third braking system can be implemented at least in part functionally by another functionally essential system of the vehicle, in particular by an electromechanical drive system and / or an electronic parking brake.

[0062] Advantageously, the third braking system can be designed to provide the braking function by means of a generator-type deceleration.

[0063] Furthermore, the third braking system can have a third detection device for detecting the braking request. It is conceivable that the third detection device comprises a button of an electronic parking brake, and / or that the third detection device is at least partially functionally implemented by another functionally essential system of the vehicle, in particular by an electronic parking brake, preferably a button of an electronic parking brake.

[0064] Furthermore, the third detection device can be signal-connected to a first conversion device of the first braking system via a first signal line, in particular directly. Furthermore, the third detection device can be signal-connected to a second conversion device of the second braking system via a second signal line, in particular directly.

[0065] The third power supply can also be used for the first braking system.

[0066] The invention further provides: a vehicle with a steering system structure and optionally a braking system or a brake-by-wire system, which can be designed as described above. The vehicle according to the invention can achieve the same advantages as those described above in connection with the steering system structure according to the invention. These advantages are incorporated herein by reference.

[0067] The invention is further illustrated in more detail with reference to the figure. It should be noted that the figure is merely descriptive and is not intended to limit the invention in any way. It shows: Fig. 1 shows an exemplary steering system structure within the scope of the present disclosure.

[0068] The Fig. 1 shows a steering system structure 100 within the scope of the present disclosure, which can advantageously be implemented in the form of a steer-by-wire system for a vehicle F, for example, a hybrid or electric vehicle, e.g., an automated (Level 4 according to the SAE definition) to autonomous (Level 5 according to the SAE definition) vehicle. In the steering system structure 100 within the scope of the present disclosure, detection devices 11, 21, 31 and conversion devices 13, 23, 33 for a steering command (which can come, for example, from the driver or the vehicle) can be mechanically decoupled from one another.

[0069] The steering system structure 100 has the following subsystems 10, 20, 30: - a first (or primary) steering system 10 (so-called autonomous steering system) for providing a steering function, which is autonomous and / or has a first (or primary) energy supply, - a second (or secondary) steering system 20 (so-called autonomous steering system) for providing a first fallback level for the steering function, which is autonomous and / or has a second (or secondary) energy supply, - and a third steering system 30 (at least partially indirect and / or functionally implemented steering system) for providing a second fallback level for the steering function, in particular by wheel-selective, possibly pulsed, braking or by wheel-selective, possibly pulsed, braking interventions, preferably via a braking system 103 of the vehicle F.

[0070] The vehicle F, in which the steering system structure 100 according to the invention can be used, can, for example, have a braking system 103, preferably a brake-by-wire system. In the braking system 103, the detection devices and the implementation devices for a braking request (which can come, for example, from the driver or the vehicle) can advantageously be mechanically decoupled from one another.

[0071] The vehicle F may further comprise at least one central control unit 110. Furthermore, the vehicle may comprise a driver-vehicle interface (HMI), for example in the form of an interactive input and output unit, e.g., comprising a display, an acoustic output device, etc.

[0072] As the Fig. As illustrated in Figure 1, two redundant autonomous steering systems 10, 20 are provided in the steering system structure 100. The steering systems 10, 20 are advantageously designed to be self-sufficient or autonomous and can be operated independently of one another and of other functional systems of the vehicle F.

[0073] The steering systems 10, 20 can be supplied with electrical energy E via two independent energy supplies E1, E2, as described in the Fig. 1 is indicated by dot-dash lines. The power supplies E1, E2 can each have a high-voltage battery that can be operated with DC voltages of approximately 60 V to approximately 1.5 kV, and each have a suitable DC / DC converter.

[0074] Each of the steering systems 10, 20 can also have a plurality of subsystems 11, 12, 13 and 21, 22, 23, such as a steering request detection (or detection device 11, 21 for detecting the steering request) and a steering request conversion (or conversion device 13, 23 for converting the steering request) and a corresponding transmission system 12, 22, such as a bus system or a data bus, e.g. with a CAN or SENT protocol.

[0075] The respective detection device 11, 21 can be designed as a steering column module. The driver's actuation of the steering wheel can be detected via steering wheel angle sensors on the steering wheel. Control electronics of the respective detection device 11, 21, comprising, for example, corresponding electronics and / or software, can passively receive the sensor data, actively query it, and, if necessary, evaluate it. Furthermore, the control electronics of the respective detection device 11, 21 can transmit the sensor data and / or the results of the evaluation to the corresponding conversion device 13, 23 via an associated transmission system 12, 22. The respective conversion device 13, 23 can also have control electronics, comprising, for example, corresponding electronics and / or software.The evaluation of sensor data from the respective detection device 11, 21 can be carried out in the control electronics of the detection device 11, 21 and / or in the control electronics of the conversion device 13, 23. The control electronics of the detection device 11, 21 and the control electronics of the conversion device 13, 23 can be provided as separate control electronics or as a common control electronics.

[0076] The respective conversion device 13, 23 can be designed as a steering gear, which can be installed, for example, on a vehicle axle, e.g., the front axle. Control electronics of the conversion device 13, 23, comprising, for example, appropriate electronics and / or software, can control an electric motor and a steering gear to convert the detected steering request. Sensors can be provided on the vehicle axle, e.g., the front axle, which can monitor the control, in particular the converted steering request. The control electronics of the conversion device 13, 23 and the sensors can be connected to one another via a data line. The control electronics of the conversion device 13, 23 can advantageously convert the steering request taking this sensor data into account.

[0077] The first steering system 10 and the second steering system 20 each have their own energy supply E1, E2, in particular a long-term energy supply. The third steering system 30 can further have a third energy supply E3, in particular a short-term energy supply. The respective long-term energy supply E1, E2 can, for example, have a DC / DC converter, which can be connected to a corresponding high-voltage battery. The short-term energy supply E3 can, for example, have a low-voltage battery and / or a supercapacitor, so-called ultracap, or the like.

[0078] The invention is based on the idea that the third steering system 30 can be provided at least partially as an indirect or dependent and / or functionally implemented or indirect steering system 30 for providing a second fallback level for the steering function. This can preferably be achieved via another functionally essential system 200 of the vehicle F, such as a braking system 103, for example, by wheel-selective, possibly pulsed, braking of the vehicle F. The braking system 103 can thus be used as a third steering request implementation (or implementation device 33 for implementing the steering request).

[0079] The third steering system 30 can advantageously comprise its own, meaning third, detection device 31. The third detection device 31 can utilize a third steering wheel angle sensor. Alternatively or additionally, the third detection device 31 can utilize a driver assistance system, e.g., a lane keeping assistant, lane recognition, an autopilot, etc. The third detection device 31 can have a third transmission system 32 for forwarding the detected steering request to a control unit 101. The control unit 101 can control the first, second, or third steering request implementation. In the event of a critical error, the control unit 101 can automatically steer the vehicle F to the side of the road. If steering is not possible, the control unit 101 can decelerate and / or brake the vehicle F, e.g., in the center of the lane, if possible to a standstill.

[0080] The steering system structure 100 can have its own control unit 101, which can be in communication with a central control unit 110 of the vehicle F. As the Fig. 1, the steering system structure 100 may comprise a control unit 101 which may be integrated in the central control unit 110 of the vehicle F in terms of software and / or hardware.

[0081] Since the subsystems of the two autonomous steering systems 10, 20 comprise multiple components, the failure of one of these components can lead to a partial or complete failure of the steering systems 10, 20. A failure of one of the braking systems can be caused by a failure of a power line, a data bus, a battery, a DC / DC converter, a fuse, a software, a sensor, an actuator, a valve, a control element, etc.

[0082] The control unit 101 can receive diagnostic data D1, D2, D3, DE1, DE2, DE3 “alive” signals and / or error states from the first autonomous steering system 10 and from the second autonomous steering system 20 and from the third indirect steering system L3 as well as from the first energy supply E1 and the second energy supply E2 and from the third energy supply E3, for example via a suitable transmission system, such as a bus system or a data bus, e.g. with a CAN or SENT protocol, e.g. via CAN bus, and / or a wireless transmission, such as a radio transmission. Furthermore, the control unit 101 can take into account operating parameters BP of the vehicle F, such as speed, load condition, etc. In addition, the control unit 101 can environmental parameters UP, such as B In particular, take into account road conditions (snow, ice, degree of wetness, dryness, coefficient of friction), temperature, humidity, etc.

[0083] The control unit 101 can decide on the basis of the diagnostic data D1, D2, D3, DE1, DE2, DE3 of the operating parameters BP of the vehicle F and / or the environmental parameters UP whether steering via wheel-selective braking pulses is possible.

[0084] The control unit 101 can decide on the basis of the diagnostic data D1, D2, D3, DE1, DE2, DE3 of the operating parameters BP of the vehicle F and / or the environmental parameters UP whether it is possible for the vehicle F to continue driving after a first or second fault in the steering systems 10, 20 or in the energy supplies E1, E2.

[0085] The control unit 101 can decide on the basis of the diagnostic data D1, D2, D3, DE1, DE2, DE3 of the operating parameters BP of the vehicle F and / or the environmental parameters UP whether steering to the edge of the road is possible and / or whether automatic deceleration and / or braking to a standstill is required.

[0086] The control unit 101 can decide on the basis of the diagnostic data D1, D2, D3, DE1, DE2, DE3 of the operating parameters BP of the vehicle F and / or the environmental parameters UP whether, after a failure of the primary and secondary steering request detection, this should be carried out on the basis of the third steering request detection.

[0087] The control unit 101 can request steering via wheel-selective braking pulses and / or deceleration and / or braking of the vehicle F from a control unit 102 of the braking system 103. The control unit 101 can, if necessary, send the steering request to the control unit 102 of the braking system 103, which can be translated into corresponding wheel-selective braking pulses.

[0088] The control unit 101 of the steering system assembly 100 and the control unit 102 of the braking system 103 may be provided as a common unit or as two separate control units.

[0089] The control unit 101 can also control the driver-vehicle interface (HMI) to inform and / or warn the driver about the errors and / or to issue a suggestion for further operation of the vehicle F, such as visiting a repair shop, pulling over to the side of the road, and / or braking the vehicle. Furthermore, the control unit can inform the driver about the remaining distance and / or the remaining travel time.

[0090] The braking system or brake-by-wire system, which is used for wheel-selective braking, can have: - a first braking system for providing a braking function, which is autonomous and / or has the first energy supply E1, - a second braking system for providing a first fallback level for the braking function, which is autonomous and / or has the second power supply E2, - and a third braking system for providing a second fallback level for the braking function, in particular by means of a generator-based deceleration.

[0091] The third braking system can be implemented at least in part functionally by another functionally essential system 200 of the vehicle F, in particular by an electromechanical drive system and / or an electronic parking brake.

[0092] Advantageously, the third braking system can be designed to provide the braking function by means of a generator-type deceleration.

[0093] Furthermore, the third braking system can have a third detection device for detecting the braking request. It is conceivable that the third detection device comprises a button of an electronic parking brake, and / or that the third detection device is at least partially functionally implemented by another functionally essential system of the vehicle F, in particular by an electronic parking brake, preferably a button of an electronic parking brake.

[0094] Furthermore, the third detection device can be signal-connected to a first conversion device of the first braking system via a first signal line, in particular directly. Furthermore, the third detection device can be signal-connected to a second conversion device of the second braking system via a second signal line, in particular directly.

[0095] The third energy supply E3 can also be used for the first braking system.

[0096] The following describes, for example, simple errors that can be counteracted using the steering system structure according to the invention, so that continued travel of the vehicle F can be ensured. The continued travel of the vehicle F after a simple error is reliably possible because, after a simple error, two options are still available to continue operating the vehicle F, for example, to detect and implement a driver's steering request. • A relevant fault scenario is the failure of the primary or secondary detection device 11, 21. In this fault scenario, redundant detection of the steering request is still ensured via the remaining secondary or primary detection device 21, 11 and the third detection device 31. The vehicle F can continue to drive, at least to a limited extent, e.g., for a specific time and / or for a specific distance. The driver can be informed of this via the driver-vehicle interface (HMI). • Another relevant error case is the failure of the primary or secondary implementation device 13, 23, when steering via wheel-selective braking pulses is simultaneously possible. Control unit 101 checks whether steering via wheel-selective braking pulses is possible based on vehicle and road condition data. In this error case, redundant implementation of the steering request is still ensured via the remaining secondary or primary steering request implementation as well as via steering via wheel-selective braking pulses. The vehicle can continue to drive, at least to a limited extent, e.g., for a specific time and / or for a specific distance. The driver can be informed of this via the driver-vehicle interface (HMI). • Another relevant error case is the failure of the first or second long-term energy supply E1, E2 for the first or second steering system 10, 20. If the first long-term energy supply E1 fails, the energy supply to the first steering system 10 is still ensured for a short time via the third energy supply E3 and the energy supply to the secondary steering system 20 is still ensured via the second energy supply E2. If the second long-term energy supply E2 fails, the energy supply to the first steering system is still ensured via the first long-term energy supply E1 and for a short time via the third energy supply E3. The vehicle F can continue to drive, at least to a limited extent, e.g. for a certain time and / or for a certain distance. The driver can be informed of this via the driver-vehicle interface HMI.

[0097] The following describes, for example, some double faults that can be counteracted using the steering system structure 100 according to the invention, so that the vehicle F can be steered by wheel-selective braking and / or decelerated to a safe state, ideally to a standstill, by automatic braking. This is possible because, even after a double fault, at least one opportunity is still provided to detect and implement a steering command and / or to decelerate the vehicle F automatically and / or based on a braking command. • A relevant error case is the simultaneous failure of the primary steering system 10 and the secondary steering system 20, when steering via wheel-selective braking pulses is possible at the same time. Control unit 101 checks whether steering via wheel-selective braking pulses is possible based on vehicle and road condition data. In this error case, the steering request is implemented via the remaining third implementation device 33, in particular via wheel-selective braking pulses, preferably with the aid of braking system 103. To this end, control unit 101 requests steering via wheel-selective braking pulses from control unit 102 of braking system 103 and sends the steering request to control unit 102 of braking system 103. Control unit 101 of steering system assembly 100 or control unit 102 of braking system 103 can translate the steering request into wheel-selective braking pulses, advantageously using vehicle and road condition data.The control unit 102 of the braking system 103 then appropriately controls the braking system 103. Furthermore, the control unit 101 can request automatic deceleration and / or emergency braking to a standstill from the braking system 103. The driver can be informed and / or warned of this via the driver-vehicle interface (HMI). • Another relevant error scenario is the simultaneous failure of the first power supply E1 and the second power supply E2 for the first and second steering systems 10, 20. In this error scenario, the power supply to the control unit 101 and the first steering system 10 is ensured for a short time by the third power supply E3. In this error scenario, the control unit 101 requests immediate deceleration and / or emergency braking to a standstill from the braking system 103. The driver can be informed and / or warned of this via the driver-vehicle interface (HMI). • A relevant error case is the failure of either the primary conversion device 13 or the secondary conversion device 23, if at the same time steering of the vehicle F via wheel-selective braking pulses is not or no longer possible. "No longer possible" means: During continued travel, the vehicle or road conditions change in such a way that steering via wheel-selective braking pulses is no longer possible. Control unit 101 detects whether steering of the vehicle F via wheel-selective braking pulses is possible depending on the operating parameters BP of the vehicle F and / or the environmental parameters UP. Possible reasons for preventing steering of the vehicle F via wheel-selective braking pulses include: ◯ Vehicle speed is too low, and / or ◯ Friction coefficient between tire and road surface is too low.

[0098] In this error event, control unit 101 requests automatic deceleration and / or emergency braking to a standstill from control unit 102 of braking system 103. The driver can be informed and / or warned of this via the driver-vehicle interface (HMI).

[0099] The above description of the figure describes the present invention exclusively by way of example. Of course, individual features of the embodiments can be freely combined with one another, provided this is technically feasible, without departing from the scope of the invention. List of reference symbols F vehicle 100 Steering system structure 10 first steering system 11 first detection device 12 first transmission system 13 first transfer device 20 second steering system 21 second detection device 22 second transmission system 23 second transfer device 30 third steering system 31 third detection device 32 third transmission system 33 third transfer device 110 central control unit 101 Control unit 102 Control unit 200 functionally essential system 103 Braking system 104 Vehicle and / or road condition recording E electrical energy E1 first energy supply E2 second power supply E3 third energy supply HMI driver-vehicle interface S1 first signal line S2 second signal line S10 automatic braking and / or emergency braking S20 automatic braking and / or emergency braking D1 Diagnostic data D2 Diagnostic data D3 Diagnostic data DE1 Diagnostic data DE2 diagnostic data DE3 diagnostic data BP operating parameters UP environmental parameters

Claims

[1] Steering system structure (100) for a vehicle (F), preferably a steer-by-wire system, in which in particular detection devices (11, 21, 31) and conversion devices (13, 23, 33) for a steering request are mechanically decoupled from one another, comprising: - a first steering system (10) for providing a steering function, which is autonomous and / or has a first energy supply (E1), - a second steering system (20) for providing a first fallback level for the steering function, which is autonomous and / or has a second energy supply (E2), - and a third steering system (30) for providing a second fallback level for the steering function, in particular by wheel-selective braking, characterized by that a control unit (101) is provided, wherein the control unit (101) is designed to - diagnostic data (D1) from the first steering system (10), - diagnostic data (D2) from the second steering system (20), - diagnostic data (D3) from the third steering system (30), - Diagnostic data (DE1) from the first power supply (E1), - Diagnostic data (DE2) from the second power supply (E2), - diagnostic data (DE3) from a third power supply (E2), - at least one operating parameter (BP) of the vehicle (F) and - to query, receive and / or process at least one environmental parameter (UP). [2] Steering system structure (100) according to claim 1, wherein the third steering system (30) is at least partially functionally implemented by a further functionally essential system (200) of the vehicle (F), in particular by a braking system (103) and / or a driver assistance system, and / or wherein the third steering system (30) is designed to provide the steering function by wheel-selective braking. [3] Steering system structure (100) according to one of the preceding claims, wherein the third steering system (30) has a third detection device (31) for detecting the steering request, wherein in particular the third detection device (31) has a third steering wheel angle sensor for detecting the steering request, and / or wherein the third detection device (31) is at least partially functionally implemented by another functionally essential system (200) of the vehicle (F), in particular by a driver assistance system, preferably a lane keeping assistant, an autopilot, etc. [4] Steering system structure (100) according to the preceding claim, wherein the third detection device (31) has a third transmission system (32) for forwarding the detected steering request to a control unit (101), and / or wherein a first signal line (S1) is provided which is designed to forward the detected steering request from the control unit (101) to the first steering system (10), and / or wherein a second signal line (S2) is provided which is designed to forward the detected steering request from the control unit (101) to the second steering system (20). [5] Steering system structure (100) according to one of the preceding claims, wherein a third energy supply (E3) is provided at least for the first steering system (10), wherein in particular the third power supply (E3) is designed to supply a control unit (101), wherein the third energy supply (E3) is preferably designed as a short-term energy supply, in particular comprising a low-voltage battery and / or a supercapacitor. [6] Steering system structure (100) according to one of the preceding claims, wherein the first steering system (10) comprises a first detection device (11) for detecting the steering request, a first conversion device (13) for converting the steering request and / or a first transmission system (12) for forwarding the detected steering request from the first detection device (11) to the first conversion device (13), and / or wherein the first steering system (10) comprises at least one control electronics for a first detection device (11), a first conversion device (13) and a first transmission system (12). [7] Steering system structure (100) according to one of the preceding claims, wherein the second steering system (20) comprises a second detection device (21) for detecting the steering request, a second conversion device (23) for converting the steering request and / or a second transmission system (22) for forwarding the detected steering request from the second detection device (21) to the second conversion device (23), and / or wherein the second steering system (20) comprises at least one control electronics for a second detection device (21), a second conversion device (23) and a second transmission system (22). [8] Steering system structure (100) according to one of the preceding claims, wherein the first power supply (E1) is designed as a long-term power supply, in particular comprising a high-voltage battery and / or a DC / DC converter, and / or wherein the second power supply (E2) is designed as a long-term power supply, in particular comprising a high-voltage battery and / or a DC / DC converter, and / or wherein the first power supply (E1) and / or the second power supply (E2) are / is designed to supply a control unit (101). [9] Steering system structure (100) according to one of the preceding claims, wherein the first steering system (10) is connected in terms of signaling, for example via a transmission system, such as a bus system, to a control unit (101), in particular for transmitting diagnostic data (D1), and / or wherein the first steering system (10) is connected in terms of control, for example via a transmission system, such as a bus system, to a control unit (101) for executing a steering request, which was detected in particular by a third detection device (31). [10] Steering system structure (100) according to one of the preceding claims, wherein the second steering system (20) is connected by signaling, for example via a transmission system, such as a bus system, to a control unit (101), in particular for transmitting diagnostic data (D2), and / or wherein the second steering system (20) is connected by control, for example via a transmission system, such as a bus system, to a control unit (101) for executing a steering request, which was detected in particular by a third detection device (31), and / or wherein the third steering system (30) is connected by signaling, for example via a transmission system, such as a bus system, to a control unit (101), in particular for transmitting diagnostic data (D3). [11] Steering system structure (100) according to one of the preceding claims, wherein the first energy supply (E1) is connected to a control unit (101) by signaling, for example via a transmission system, such as a bus system, in particular for transmitting diagnostic data (DE1), and / or wherein the second energy supply (E2) is connected to a control unit (101) by signaling, for example via a transmission system, such as a bus system, in particular for transmitting diagnostic data (DE2), and / or wherein the third energy supply (E3) is connected to a control unit (101) by signaling, for example via a transmission system, such as a bus system, in particular for transmitting diagnostic data (DE3). [12] Steering system structure (100) according to one of the preceding claims, wherein the control unit (101) is integrated in a central control unit of the vehicle (F) in terms of software and / or hardware. [13] Steering system structure (100) according to the preceding claim, wherein the control unit (101) is designed to - to control the first steering system (10) and / or the second steering system (20) to execute the steering request, preferably as a function of diagnostic data (D1, D2, D3, DE1, DE2, DE3) from the first steering system (10), from the second steering system (20), from the third steering system (30), from the first energy supply (E1), from the second energy supply (E2), from the third energy supply (E3), at least one operating parameter (BP) of the vehicle (F), in particular speed, load condition, etc., and / or at least one environmental parameter (UP), in particular road condition, coefficient of friction, temperature, humidity, etc. [14] Steering system structure (100) according to one of the preceding claims, wherein the control unit (101) is designed to -- to control a further functionally essential system (200) of the vehicle (F), in particular a braking system (103), in order to provide the steering function by wheel-selective braking, preferably as a function of diagnostic data (D1, D2, D3, DE1, DE2, DE3) from the first steering system (10), from the second steering system (20), from the third steering system (30), from the first energy supply (E1), from the second energy supply (E2), from the third energy supply (E3), at least one operating parameter (BP) of the vehicle (F), in particular speed, load condition, etc., and / or at least one environmental parameter (UP), in particular road condition, coefficient of friction, temperature, humidity, etc. [15] Vehicle having a steering system structure (100) according to any one of the preceding claims.

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