Steering system and method for operating a steering system

Abstract

The invention relates to a steering system, in particular a steering-by-wire system, comprising: an operating unit, which comprises at least one feedback actuator for generating a steering resistance and / or a restoring torque acting on a steering handle and at least one feedback control unit for controlling the operation of the feedback actuator; at least one wheel steering angle adjuster mechanically separated from the operating unit, said wheel steering angle adjuster comprising at least one steering actuator for changing a wheel steering angle of at least one wheel and at least one steering control unit for controlling the operation of the steering actuator; and a transmission unit which connects the operating unit and the wheel steering angle adjuster to each other at least in a communicative manner. According to the invention, the feedback control unit is provided for actuating the steering actuator in at least one malfunction operating state in which a malfunction and / or malfunction of the steering control unit occurs.

Description

Technical Field

[0001] The invention relates to a steering system according to the preamble of claim 1. The invention also relates to a vehicle having such a steering system and to a method for operating such a steering system. Background Art

[0002] Vehicles with conventional steering systems are known from the prior art, in which a steering handle, for example in the form of a steering wheel, is mechanically fixedly connected via a steering column to a wheel steering angle controller in the form of a steering gear. In order to provide steering support, the wheel steering angle controller often has a redundantly designed steering actuator in the form of a servomotor. In addition, in the event of a fault, the driver can provide an additional fallback level for mechanically steering the vehicle.

[0003] Furthermore, vehicles are known which have steer-by-wire systems which are sufficient without a direct mechanical connection between the steering handle and the steered wheels and in which the steering specification is transmitted electrically. Such steer-by-wire systems usually include an operating unit with a steering handle and a feedback actuator and at least one wheel steering angle regulator mechanically separated from the operating unit, which has a steering actuator for changing the wheel steering angle. Due to the lack of a mechanical feedthrough, the driver cannot provide an additional retraction level in this case, so that other measures must be taken in the event of a fault.

[0004] In this regard, a readily conceivable possibility is to provide additional redundancy so that overall at least three separate fallback levels are available. However, such additional redundancy carries high costs, so that other solutions become the focus.

[0005] Therefore, it is known to use a vehicle system other than the steering system, such as, for example, the drive and / or brake system, as a further retraction level. Such methods are known, for example, from DE 102017221289 A1 and DE 102022103808 A1. However, it is not always possible or only conditionally possible to use other vehicle systems, so that in principle there is a need for solutions that turn to the inside. Summary of the invention

[0006] Starting from this, the object of the present invention is in particular to provide a steering system with improved properties in terms of operational reliability. This object is achieved by the features of claims 1, 8 and 9, while advantageous embodiments and improvements of the invention can be found in the dependent claims.

[0007] The present invention relates to a steering system, which has: an operating unit, which includes at least one feedback actuator for generating a steering resistance and / or a restoring torque acting on a steering handle and at least one feedback control unit for controlling the operation of the feedback actuator; at least one wheel steering angle regulator mechanically separated from the operating unit, which includes at least one steering actuator for changing the wheel steering angle of at least one wheel and at least one steering control unit for controlling the operation of the steering actuator; and a transmission unit, which connects the operating unit and the wheel steering angle regulator to each other at least for communication.

[0008] It is proposed that the feedback control unit is provided in at least one faulty operating state in which a fault and / or failure of the steering control unit occurs to control the steering actuator and to be more precise, in particular, to control the steering actuator via the transmission unit. The feedback control unit of the operating unit thus serves as a backup control for the wheel steering angle regulator, wherein the feedback control unit can be provided, depending on the faulty operating state, to completely replace the steering control unit of the wheel steering angle regulator or to cooperate with the steering control unit for controlling the steering actuator. This design can in particular increase the operational reliability of the steering system and at the same time provide an advantageously cost-effective solution.

[0009] The steering system is provided for use in a vehicle, in particular in a motor vehicle, and is in particular configured as a steer-by-wire system, wherein the steering presetting of the driver is advantageously transferred to the wheels in a purely electrical manner. In principle, the vehicle in this respect can also include an automated and / or autonomous driving mode. In this respect, an "operating unit" should refer to an input unit that can be operated by the driver for controlling at least one wheel steering angle regulator. In addition, the operating unit can also include a steering handle, for example, configured as a steering wheel. In addition, the operating unit can include at least one disconnecting switch unit, advantageously in the form of one or more phase disconnecting switches, which is used to separate the feedback control unit from the feedback actuator. The feedback actuator is in particular configured as an electric motor and in principle can include a plurality of independent sub-machines, which are advantageously constructed in the same structure. In addition, the feedback control unit can include at least one computing logic circuit, at least one power electronic device, for example in the form of a B6 bridge circuit, and at least one driver unit for providing a control voltage and / or a control current for at least one power switch of the power electronic device. In addition, the feedback control unit can have a plurality of control electronics that are independent of each other, which are advantageously constructed in the same structure and can respectively include a computing logic circuit, a power electronics device and a drive unit. "Wheel steering angle regulator" should refer to a regulating unit that is operatively connected to at least one wheel, which is arranged to transmit a steering preset to the wheel by changing the wheel steering angle of at least one wheel and thereby advantageously at least control the orientation of the wheel and / or influence the driving direction of the vehicle. For this purpose, the wheel steering angle regulator advantageously includes at least one steering regulating element, for example in the form of a rack, and a steering actuator that is particularly operatively connected to the steering regulating element. In addition, the wheel steering angle regulator can include at least one additional disconnecting switch unit, advantageously in the form of one or more phase disconnecting switches, which is used to separate the steering control unit from the steering actuator. In addition, the wheel steering angle regulator can be configured in particular as a central regulator and can be assigned to at least two, in particular steerable wheels or configured as a single wheel regulator and assigned to just one steerable wheel. The steering actuator is designed in particular as an electric motor and can in principle include a plurality of further sub-machines that are independent of one another, which are advantageously constructed in an identical manner. In addition, the steering control unit can include at least one further computing logic, at least one further power electronics, for example in the form of a B6 bridge circuit, and at least one further driver unit for providing a control voltage and / or a control current for at least one further power switch of the further power electronics. In addition, the steering control unit can have a plurality of further control electronics that are independent of one another, which are advantageously constructed in an identical manner and can each include a further computing logic, a further power electronics, and a further driver unit.

[0010] In addition, a "transmission unit" should particularly refer to an electrical, optical and / or wireless connection for exchanging data and / or information and / or parameters between an operating unit and at least one wheel steering angle regulator. In addition, the transmission unit can provide a direct connection between the operating unit and at least one wheel steering angle regulator or an indirect connection between the operating unit and at least one wheel steering angle regulator, such as, for example, through a central computing unit. The transmission unit can advantageously be constructed as a bus connection. It is particularly advantageous that the transmission unit can include a private CAN and / or processor-to-processor communication connection between the feedback control unit and the steering control unit. It is particularly preferred that the transmission unit is constructed so that in a faulty operating state, fault information can be transmitted from the wheel steering angle regulator to the operating unit and the feedback control unit is required to take over the control of the steering actuator or at least one sub-machine of the steering actuator. In addition, a "fault and / or malfunction of the steering control unit" should particularly refer to a fault and / or at least partial or complete malfunction of the steering control unit itself and / or a peripheral structural assembly that cooperates with the steering control unit, such as, for example, a fault and / or a malfunction of the energy supply mechanism and a fault of the steering control unit caused thereby. "Setting" should particularly refer to special programming, design and / or equipment. “An object is provided for a specific function” is intended to mean, in particular, that the object performs and / or executes this specific function in at least one application and / or operating state.

[0011] It is further proposed that the feedback control unit is configured to actuate the feedback actuator with reduced power or to set an actuation of the feedback actuator in a faulty operating state. In this way, a high level of operational reliability can be achieved in particular. Such a design also has the advantage that the driver can continue to steer the vehicle in the desired direction even with reduced feedback or without feedback from the feedback actuator to the steering handle.

[0012] It is further proposed that the steering system comprises at least one, in particular additional, switch unit for electrically connecting the feedback control unit to the steering actuator. The switch unit is preferably different from the disconnect switch unit for separating the feedback control unit from the feedback actuator and from another disconnect switch unit for separating the steering control unit from the steering actuator. In addition, the switch unit can in principle be integrated into the wheel steering angle regulator. However, according to an advantageous design, it is proposed that the switch unit is integrated into the operating unit and is arranged between the power electronics of the feedback control unit and the transmission unit in terms of line technology. Preferably, the switch unit establishes an electrical connection between the feedback control unit and the steering actuator via the transmission unit. It is particularly preferred that the feedback control unit, in particular the power electronics, is directly electrically connected to the steering actuator via the switch unit and the transmission unit. As a result, an advantageous control possibility of the steering actuator can be realized with the aid of the feedback control unit.

[0013] It is further proposed that the wheel steering angle regulator comprises at least one detection sensor device, which is particularly assigned to the steering actuator and is used to detect at least one operating characteristic variable of the steering actuator, wherein the detection sensor device is configured to transmit the operating characteristic variable to a feedback control unit, particularly with sufficient quality, preferably via a transmission unit, at least in a faulty operating state, and wherein the feedback control unit is configured to control the steering actuator in the faulty operating state as a function of the operating characteristic variable. It is particularly advantageous that the operating characteristic variable can be a rotor position signal of the steering actuator. In principle, the operating characteristic variable can also be provided redundantly and / or via two redundant channels. As a result, advantageous synchronization can be achieved when the steering actuator is controlled by means of the feedback control unit.

[0014] If the feedback control unit is designed to take over the control of the steering actuator in a faulty operating state within a predefined fault tolerance time, a particularly unobtrusive emergency function that also meets the corresponding safety requirements can be implemented. In this case, in particular, the feedback control unit, the switching unit, the transmission unit and / or the steering actuator can be designed accordingly to enable the control of the steering actuator within the predefined fault tolerance time.

[0015] According to another embodiment, it is proposed that the steering actuator comprises at least two steering sub-machines independent of one another and the steering control unit comprises at least two steering control electronics independent of one another, wherein one of the steering control electronics is assigned to each steering sub-machine, and wherein the feedback control unit is configured to replace at least one of the steering control electronics or both of the steering control electronics in a faulty operating state. In this case, the wheel steering angle regulator thus provides two separate and independent control channels, wherein one of the steering sub-machines and one of the steering control electronics is assigned to each control channel. This makes it possible to achieve an advantageous redundancy in the wheel steering angle regulator, thereby further improving the operational reliability.

[0016] It is further proposed that the feedback actuator comprises at least two feedback sub-machines independent of one another and the feedback control unit comprises at least two feedback control electronics independent of one another, wherein one of the feedback control electronics is assigned to each feedback sub-machine and wherein at least one of the feedback control electronics is configured to replace at least a part of the steering control unit or the entire steering control unit in a faulty operating state. In this case, the operating unit thus provides at least two separate and independent control channels, wherein one of the feedback sub-machines and one of the feedback control electronics are assigned to each control channel. As a result, advantageous redundancy can be achieved in the operating unit, thereby further improving operational reliability.

[0017] Furthermore, preferably, the first feedback control electronics are assigned to the first steering control electronics and are configured to replace the first steering control electronics and take over the control of the first steering sub-machine of the steering actuator in a first faulty operating state and more precisely when there is a fault and / or failure of the first steering control electronics, while the second feedback control electronics are assigned to the second steering control electronics and are configured to replace the second steering control electronics and take over the control of the second steering sub-machine of the steering actuator in a second faulty operating state and more precisely when there is a fault and / or failure of the second steering control electronics. For this purpose, the first feedback control electronics can be communicatively connected to the first steering control electronics via a first inter-processor communication connection, and the second feedback control electronics can be communicatively connected to the second steering control electronics via a second inter-processor communication connection. In this case, the feedback control unit can thus be configured to cooperate with the steering control unit for controlling the steering actuator and partially replace the steering control unit. It is particularly advantageous if the first and second feedback control electronics are also configured to replace the first and second steering control electronics and take over the control of the first and second steering sub-machines of the steering actuator in a third faulty operating state and more precisely in the event of a fault and / or failure of the first and second steering control electronics. In this case, the feedback control unit is thus configured to completely replace the steering control unit.

[0018] Furthermore, a method for operating the aforementioned steering system is proposed, wherein in at least one faulty operating state in which a fault and / or failure of a steering control unit is detected, a feedback control unit is used to control the steering actuator. Furthermore, the operation of the wheel steering angle regulator can be monitored, in particular via the transmission unit. In this way, in particular the advantages already mentioned above can be achieved. In particular, the operational reliability of the steering system can be increased and at the same time an advantageously cost-effective solution can be provided.

[0019] The steering system and the method for the steering system are not to be limited to the above-described applications and embodiments. In particular, the steering system and the method for operating the steering system can have a different number of individual elements, components and units mentioned above in order to implement the principle of action described above. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Further advantages emerge from the following description of the drawings. In the drawings, various exemplary embodiments of the invention are shown.

[0021] in:

[0022] Figure 1a- b shows a simplified illustration of a vehicle having a steering system designed as a steer-by-wire system;

[0023] Figure 2 A simplified schematic sketch showing the construction of the steering system;

[0024] Figure 3 An exemplary flow chart with essential method steps of a method for operating a steering system is shown; and

[0025] Figure 4 Another exemplary embodiment of a steering system is shown in more detail. DETAILED DESCRIPTION

[0026] Figure 1a and 1b A vehicle 44a, designed as a passenger car by way of example, is shown in a simplified illustration, which has a plurality of wheels 24a and a steering system 10a. The steering system 10a has an operative connection to the wheels 24a and is provided for influencing the driving direction of the vehicle 44a. Furthermore, the steering system 10a is designed here as a steer-by-wire system, wherein the steering specification is transmitted electrically to the wheels 24a in at least one operating state.

[0027] The steering system 10a has an operating unit 12a which can be operated in particular by a driver and / or a passenger. The operating unit 12a includes a steering handle 16a, for example in the form of a steering wheel, and a feedback actuator 14a, which is in particular mechanically coupled to the steering handle 16a. In the present case, the feedback actuator 14a is provided, at least in a normal operating state, for providing a feedback torque and thereby for generating a steering feel, in particular in the form of a steering resistance and / or a return torque acting on the steering handle 16a. To this end, the feedback actuator 14a includes at least one electric motor (not explicitly shown), which is in particular designed as a permanently excited synchronous motor. In addition, the operating unit 12a includes a feedback control unit 18a which is electrically connected to the feedback actuator 14a and is used to control the operation of the feedback actuator 14a. Referring below to Figure 2 The configuration of the feedback control unit 18a is described. As an alternative, the steering handle can also be configured as a joystick, a steering rod and / or a steering ball, etc. In addition, the feedback actuator can include a plurality of electric motors.

[0028] In addition, the steering system 10a has a wheel steering angle regulator 20a known per se. The wheel steering angle regulator 20a is mechanically separated from the operating unit 12a. The wheel steering angle regulator 20a is connected to the operating unit 12a purely electrically. In addition, the wheel steering angle regulator 20a is configured as a central regulator by way of example. The wheel steering angle regulator 20a has an operative connection with at least two of the wheels 24a, in particular the two front wheels, and is configured to convert a steering preset into a steering movement of the wheels 24a. For this purpose, the wheel steering angle regulator 20a includes a steering adjustment element 46a, which is configured as a rack by way of example, and a steering actuator 22a that cooperates with the steering adjustment element 46a. The steering actuator 22a here includes at least one other electric motor (not explicitly shown) that is configured as a permanent magnet excited synchronous motor and is configured to provide a steering torque for adjusting the steerable wheels 24a. In addition, the wheel steering angle regulator 20a includes a steering control unit 26a electrically connected to the steering actuator 22a for controlling the operation of the steering actuator 22a. Figure 2 The design of the steering control unit 22a is described below. In principle, the steering system can of course also include a plurality of wheel steering angle regulators, in particular designed as single-wheel regulators, wherein in this case each wheel steering angle regulator can have a steering actuator and a steering control unit. Furthermore, the steering actuator can include a plurality of electric motors or actuators other than permanently excited synchronous motors.

[0029] Furthermore, the steering system 10a has a transmission unit 28a, which connects the operating unit 12a and the wheel steering angle regulator 20a to each other at least in a communicative manner. The transmission unit 28a is provided for exchanging data and / or information between the operating unit 12a and the wheel steering angle regulator 20a. Furthermore, the transmission unit 28a is provided in the present case for energy transmission between the operating unit 12a and the wheel steering angle regulator 20a. Here, the transmission unit 28a is designed as an electrical connecting line, in particular as a bus connection. Furthermore, the transmission unit 28a in the present case includes, by way of example, a private CAN and an interprocessor communication connection between the feedback control unit 18a and the steering control unit 26a.

[0030] Figure 2 The basic internal structure of the operating unit 12a and the wheel steering angle regulator 20a is shown.

[0031] The feedback control unit 18a comprises a power path 48a with a power electronic device 32a. The power electronic device 32a is designed as an output stage, for example as a B6 bridge circuit and has an electrical connection to an energy supply (not shown), for example a vehicle battery, on the one hand, and an electrical connection to the feedback actuator 14a on the other hand. The power electronic device 32a is used here to supply the feedback actuator 14a. In principle, the vehicle can of course also have a plurality of energy supply networks, which can also be designed redundantly.

[0032] In addition, the feedback control unit 18a includes a control path 50a with a computing logic circuit 52a and a driver unit 54a. The computing logic circuit 52a can include at least one processor, for example. The driver unit 54a can be configured as a half-bridge driver and / or a gate driver, for example. The driver unit 54a has an electrical connection with the computing logic circuit 52a on the one hand and an electrical connection with the power electronic device 32a on the other hand. The driver unit 54a is provided for controlling at least one power switch (not shown) of the power electronic device 32a and advantageously controls all power switches of the power electronic device and provides a control voltage and / or a control current for at least one power switch. In principle, the operating unit can of course also include a plurality of computing logic circuits, power electronic devices and / or driver units. In addition, the corresponding power electronic device can have different power switches, such as, for example, phase circuit breakers and / or track switches and / or short-circuit switches.

[0033] In addition, the operating unit 12a includes at least one detection sensor device 56a assigned to the feedback actuator 14a, which is used to detect at least one operating characteristic variable of the feedback actuator 14a and preferably multiple operating characteristic variables of the feedback actuator 14a. The detection sensor device 56a can be configured as a rotor position sensor, for example, and is configured to detect a rotor position signal of the feedback actuator 14a. The detection sensor device 56a has an electrical connection to the feedback control unit 18a, in particular the calculation logic circuit 52a. Here, the feedback control unit 18a is configured to control the feedback actuator 14a in a normal operating state depending on the operating characteristic variable of the feedback actuator 14a.

[0034] The steering control unit 26a comprises another power path 58a with another power electronic device 60a. The other power electronic device 60a is designed as an output stage, for example as a B6 bridge circuit and has an electrical connection to another energy supply mechanism (not shown), such as a vehicle battery, on the one hand, and an electrical connection to the steering actuator 22a on the other hand. The other power electronic device 60a is used here to supply the steering actuator 22a. In principle, the vehicle can of course also have a plurality of other energy supply networks, which can also be designed redundantly.

[0035] In addition, the steering control unit 26a includes another control path 62a having another computing logic circuit 64a and another driver unit 66a. The other computing logic circuit 64a can include at least one other processor, for example. The other driver unit 66a can be configured as a half-bridge driver and / or a gate driver, for example. The other driver unit 66a has an electrical connection with the other computing logic circuit 64a on the one hand and an electrical connection with the other power electronic device 60a on the other hand. The other driver unit 66a is provided for controlling at least one other power switch (not shown) and advantageously controls all other power switches of the other power electronic device 60a and provides a control voltage and / or a control current for at least one other power switch. In principle, the wheel steering angle regulator can of course also include a plurality of computing logic circuits, power electronic devices and / or driver units.

[0036] In addition, the wheel steering angle regulator 20a includes at least one other detection sensor device 34a assigned to the steering actuator 22a, which is used to detect at least one operating characteristic parameter of the steering actuator 22a. The other detection sensor device 34a can be constructed as a rotor position sensor and is provided for the rotor position signal of the steering actuator 22a. The other detection sensor device 34a has at least an electrical connection with the steering control unit 26a, especially another calculation logic circuit 64a. However, in principle, it is also possible to use the inter-processor communication connection between another detection sensor device and the steering control unit. In addition, the other detection sensor device 34a has an electrical connection with the feedback control unit 18a, especially the calculation logic circuit 52a in the current situation. Here, the steering control unit 26a is provided to control the steering actuator 22a in a normal operating state depending on the operating characteristic parameter of the steering actuator 22a.

[0037] Due to the lack of a mechanical lead-through between the operating unit 12a and the wheel steering angle regulator 20a, the driver cannot provide an additional retraction level, so that in the event of a faulty operating state in which a fault and / or failure of the steering control unit 26a occurs, further measures must be taken.

[0038] In the present case, a solution for turning to the inside to improve the operating possibilities is pursued. Here, the feedback control unit 18a is configured to control the steering actuator 22a in at least one faulty operating state in which a fault and / or failure of the steering control unit 26a occurs. Here, the feedback control unit 18a is configured to take over the control of the steering actuator 22a within a predefined fault tolerance time. The feedback control unit 18a is therefore used as a backup control mechanism for the wheel steering angle regulator 20a. In addition, the transmission unit 28a is configured so that in the faulty operating state, fault information can be transmitted from the wheel steering angle regulator 20a to the operating unit 12a and the feedback control unit 18a is required to take over the control of the steering actuator 22a. According to the present embodiment, the feedback control unit 18a is configured here to completely replace the steering control unit 26a in the faulty operating state and set the control of the feedback actuator 14a. However, as an alternative, it is also possible to control with reduced power.

[0039] For this purpose, the steering system 10a comprises, in particular, an additional switching unit 30a for electrically connecting the feedback control unit 18a to the steering actuator 22a. The switching unit 30a is integrated into the operating unit 12a and is arranged in terms of circuit technology between the power electronics 32a and the transmission unit 28a. The switching unit 30a is provided for establishing an electrical connection between the feedback control unit 18a and the steering actuator 22a via the transmission unit 28a.

[0040] Furthermore, the detection sensor device 34a is configured to provide operating characteristic variables of the steering actuator 22a via a transmission unit 28a of the feedback control unit 18a, and the feedback control unit 18a is configured to use and / or take into account such operating characteristic variables when controlling the steering actuator 22a in a faulty operating state.

[0041] This embodiment makes it possible to achieve a high level of operational reliability, wherein the driver can continue to steer vehicle 44a in the desired direction even without feedback from feedback actuator 14a at steering handle 16a.

[0042] at last, Figure 3 An exemplary flow chart with essential method steps of a method for operating a steering system 10 a is shown.

[0043] Method step 70a corresponds to a normal operating state, which is particularly error-free. In this case, the feedback actuator 14a of the operating unit 12a is controlled by the feedback control unit 18a of the operating unit 12a to generate a steering resistance and / or a restoring torque acting on the steering handle 16a. In addition, the steering actuator 22a of the wheel steering angle regulator 20a is controlled by the steering control unit 26a of the wheel steering angle regulator 20a to adjust the wheel steering angle of the wheel 24a, for example, depending on the steering specification on the steering handle 16a.

[0044] In method step 72a, a fault and / or failure of the steering control unit 26a occurs and thus a faulty operating state occurs. Due to the faulty operating state, a fault message is transmitted from the wheel steering angle regulator 20a to the operating unit 12a via the transmission unit 28a and the feedback control unit 18a is requested to take over the control of the steering actuator 22a.

[0045] Subsequently, in method step 74a, the switch unit 30a is actuated in such a way that the feedback control unit 18a is disconnected from the feedback actuator 14a and connected to the steering actuator 22a. In principle, two separate switch units can also be used for this purpose. In principle, a disconnect switch unit (not shown) of the wheel steering angle regulator 20a can also be actuated similarly to disconnect the steering control unit 26a from the steering actuator 22a.

[0046] In method step 76a, the steering actuator 22a of the wheel steering angle regulator 20a is then controlled by the feedback control unit 18a of the operating unit 12a, in particular for adjusting the wheel steering angle of the wheel 24a, for example as a function of the steering specification on the steering handle 16a. Advantageously, the feedback control unit 18a takes over within a predefined fault tolerance time. Thus, the feedback control unit 18a of the operating unit 12a serves as a backup control for the wheel steering angle regulator 20a in a faulty operating state.

[0047] Figure 3 The exemplary flow chart in the diagram is intended to depict only an exemplary method for operating the steering system 10a. In particular, individual method steps may also be varied or additional method steps may be added. In this respect, it is conceivable, for example, to use the feedback control unit in a faulty operating state for controlling the feedback actuator and for controlling the steering actuator.

[0048] exist Figure 4Another embodiment of the present invention is shown in FIG. The following description and drawings are essentially limited to the differences between the embodiments, wherein in principle, reference can also be made to other embodiments, in particular the drawings and / or descriptions of FIGS. 1 to 3 , for identically represented components, in particular for components with the same reference numerals. In order to distinguish between the embodiments, the letter a is added after the reference numerals of the embodiments of FIGS. 1 to 3 . Figure 4 In the embodiment, the letter a is replaced by the letter b.

[0049] Figure 4 The further exemplary embodiment of the invention differs from the preceding exemplary embodiment at least substantially in the design of the feedback actuator 14b and the feedback control unit 18b of the operating unit 12b and the steering actuator 22b and the steering control unit 26b of the wheel steering angle regulator 20b.

[0050] In this case, both the operating unit 12 b and the steering angle regulator 20 b each provide two separate and independent control channels.

[0051] Therefore, the feedback actuator 14b includes two feedback sub-machines 40b, 40b' that are independent of each other and the feedback control unit 18b includes two feedback control electronics 42b, 42b' that are independent of each other, wherein one of the feedback control electronics 42b, 42b' is assigned to each feedback sub-machine 40b, 40b'. In addition, each control channel of the operating unit 12b can include a disconnect switch unit 68b, 68b', advantageously in the form of one or more phase disconnect switches, which is used to separate the corresponding feedback control electronics 42b, 42b' from the corresponding feedback sub-machine 40b, 40b'. The feedback sub-machines 40b, 40b' and the feedback control electronics 42b, 42b' can be constructed in the same structure. In addition, the feedback control electronics 42b, 42b' can each have a computing logic circuit 52b, 52b', a power electronics 32b, 32b' and a driver unit 54b, 54b'. Furthermore, the operating unit 12 b comprises detection electronics 56 b which are associated with the feedback actuator 14 b and are used to detect operating characteristic variables of the two feedback submachines 40 b , 40 b ′.

[0052] In addition, the steering actuator 22b includes two steering sub-machines 36b, 36b' that are independent of each other, and the steering control unit 26b includes two steering control electronic devices 38b, 38b' that are independent of each other, wherein a steering control electronic device 38b, 38b' is assigned to each steering sub-machine 36b, 36b'. In addition, each control channel of the wheel steering angle regulator 20b can include another disconnecting switch unit 69b, 69b', which is advantageously in the form of one or more phase disconnecting switches, and is used to separate the corresponding steering control electronic device 38b, 38b' from the corresponding steering sub-machine 36b, 36b'. The steering sub-machines 36b, 36b' and the steering control electronic devices 38b, 38b' are constructed in the same structure. In addition, the steering control electronic devices 38b, 38b' respectively have another computing logic circuit 64b, 64b', another power electronic device 60b, 60b' and another drive unit 66b, 66b'. Furthermore, the steering angle controller 20b comprises a further detection sensor device 34b which is associated with the steering actuator 22b and is used to detect characteristic operating variables of the two steering submachines 36b, 36b'.

[0053] Furthermore, in the present case, each control channel of the operating unit 12b comprises an additional switching unit 30b, 30b', which is used to electrically connect the corresponding feedback control electronics 42b, 42b' to one of the steering submachines 36b, 36b'. The electrical connection is again established between the operating unit 12b and the wheel steering angle regulator 20b via the transmission unit 28b.

[0054] In this case, the first feedback control electronics 42b is assigned to the first steering control electronics 38b and is configured to replace the first steering control electronics 38b and take over the control of the first steering sub-machine 36b of the steering actuator 22b in a first faulty operating state and more precisely in the presence of a fault and / or failure of the first steering control electronics 38b, while the second feedback control electronics 42b' is assigned to the second steering control electronics 38b' and is configured to replace the second steering control electronics 38b' and take over the control of the second steering sub-machine 36b' of the steering actuator 22b in a second faulty operating state and more precisely in the presence of a fault and / or failure of the second steering control electronics 38b'. Thus, in the first faulty operating state and in the second faulty operating state, the feedback control unit 18b is configured to cooperate with the steering control unit 26b for the control of the steering actuator 22b and partially replace the steering control unit 26b, and thus replace the first steering control electronics 38b or the second steering control electronics 38b'. At the same time, the feedback control unit 18 b can be configured in these cases to actuate the feedback actuator 14 b , more precisely the feedback submachines 40 b , 40 b ′, with reduced power.

[0055] Furthermore, the first feedback control electronics 42b and the second feedback control electronics 42b' are configured to replace the first steering control electronics 38b and the second steering control electronics 38b' and take over the control of the first steering sub-machine 36b and the second steering sub-machine 36b' of the steering actuator 22b in the third faulty operating state and more precisely in the event of a fault and / or failure of the first steering control electronics 38b and the second steering control electronics 38b'. Thus, in the third faulty operating state, the feedback control unit 18b is configured to completely replace the steering control unit 26b, and thus replace the first steering control electronics 38b and the second steering control electronics 38b'. Furthermore, in this case, the feedback control unit 18b is configured to set the control of the feedback actuator 14b with reduced power.

[0056] In addition, Figure 4, a first faulty operating state is shown by way of example (outlined by lines and components drawn in dashed lines). In this case, the first feedback control electronics 42b is configured to replace the first steering control electronics 38b and take over the control of the first steering sub-machine 36b of the steering actuator 22b. At the same time, the first feedback control electronics 42b is configured to set the control of the first feedback sub-machine 40b in the faulty operating state. The second feedback control electronics 42b' is also configured to control the second feedback sub-machine 40b', so that in this case the feedback actuator 14b is controlled with reduced power. In addition, the second steering control electronics 38b' is also configured to control the second steering sub-machine 36b', so that the first feedback control electronics 42b and the second steering control electronics 38b' work together in this case to control the steering actuator 22b.

Claims

1. A steering system (10a; 10b), in particular a steer-by-wire system, comprising: an operating unit (12a; 12b), the operating unit comprising at least one feedback actuator (14a; 14b) for generating a steering resistance and / or a return torque acting on a steering handle (16a) and at least one feedback control unit (18a; 18b) for controlling the operation of the feedback actuator (14a; 14b); at least one wheel steering angle adjustment unit (18a; 18b) mechanically separated from the operating unit (12a; 12b); The invention relates to a wheel steering angle regulator (20a; 20b), the wheel steering angle regulator comprising at least one steering actuator (22a; 22b) for changing the wheel steering angle of at least one wheel (24a) and at least one steering control unit (26a; 26b) for controlling the operation of the steering actuator (22a; 22a); and a transmission unit (28a; 28b), the transmission unit connecting the operating unit (12a; 12b) and the wheel steering angle regulator (20a; 20b) to each other at least in a communicative manner, characterized in that: The feedback control unit (18a; 18b) is provided for controlling a steering actuator (22a; 22b) in at least one faulty operating state in which a fault and / or failure of the steering control unit (26a; 26b) occurs.

2. The steering system (10a; 10b) according to claim 1, characterized in that The feedback control unit (18a; 18b) is provided for actuating the feedback actuator (14a; 14b) with reduced power in a faulty operating state or for setting an actuation of the feedback actuator (14a; 14b).

3. The steering system (10a; 10b) according to claim 1 or 2, characterized in that At least one switching unit (30a; 30b, 30b') for electrically connecting a feedback control unit (18a; 18b) to a steering actuator (22a; 22b), wherein the switching unit (30a; 30b, 30b') is integrated into an operating unit (12a; 12b) and is arranged in terms of circuit technology between a power electronic device (32a; 32b, 32b') of the feedback control unit (18a; 18b) and a transmission unit (28a; 28b).

4. The steering system (10a; 10b) according to any one of the preceding claims, characterized in that The wheel steering angle regulator (20a; 20b) comprises at least one detection sensor device (34a; 34b) for detecting at least one operating characteristic parameter of a steering actuator (22a; 22b), wherein the detection sensor device is configured to transmit the operating characteristic parameter to a feedback control unit (18a; 18b) at least in a faulty operating state, and wherein the feedback control unit (18a; 18b) is configured to control the steering actuator (22a; 22b) in dependence on the operating characteristic parameter in the faulty operating state.

5. The steering system (10a; 10b) according to any one of the preceding claims, characterized in that The feedback control unit (18a; 18b) is provided to take over the control of the steering actuator (22a; 22b) within a predefined fault tolerance time in a fault operating state.

6. The steering system (10b) according to any one of the preceding claims, characterized in that The steering actuator (22b) comprises at least two steering sub-machines (36b, 36b') which are independent of each other, and the steering control unit (26b) comprises at least two steering control electronic devices (38b, 38b') which are independent of each other, wherein each steering sub-machine (36b, 36b') is assigned one of the steering control electronic devices (38b, 38b'), and wherein the feedback control unit (18b) is configured to replace at least one of the steering control electronic devices (38b, 38b') or both of the steering control electronic devices (38b, 38b') in a faulty operating state.

7. The steering system (10b) according to any one of the preceding claims, characterized in that The feedback actuator (14b) comprises at least two feedback sub-machines (40b, 40b') which are independent of each other, and the feedback control unit (18b) comprises at least two feedback control electronic devices (42b, 42b') which are independent of each other, wherein each feedback sub-machine (40b, 40b') is assigned one of the feedback control electronic devices (42b, 42b'), and wherein at least one of the feedback control electronic devices (42b, 42b') is configured to replace at least a part of the steering control unit (26b) or the entire steering control unit (26b) in a faulty operating state.

8. A vehicle (44a), in particular a motor vehicle, having a steering system (10a; 10b) according to any of the preceding claims.

9. A method for operating a steering system (10a; 10b) according to any one of claims 1 to 7, wherein the feedback control unit (18a; 18b) is used to control a steering actuator (22a; 22b) in at least one faulty operating state in which a fault and / or malfunction of the steering control unit (26a; 26b) is detected.

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