Device for an automatic parking brake system

Abstract

The invention relates to a device (1) for operating an actuator (3) of an automatic parking brake system of a motor vehicle (2), wherein the device (1) has a switching mechanism (13) assigned to the actuator (3), which enables the selective operation of the actuator (3) using one of two assigned control units (9, 10) by switching. The invention also relates to a method for operating such a device (1).

Description

TECHNICAL FIELD

[0001] The invention relates to a device for operating at least one actuator of an automatic parking brake system of a motor vehicle. The invention also relates to a method for operating such a device. BACKGROUND

[0002] It is known to use an automatic parking brake system in a motor vehicle. Such a parking brake system serves the purpose of immobilizing the associated motor vehicle when required, in particular in a parking position, and to prevent the motor vehicle from rolling away. To this end, the parking brake system usually has a parking brake, also referred to as a parking brake, which can be operated by means of a corresponding actuator, i.e. immobilized and released. The parking brake system is usually operated by means of a device having a controller. The controller, also referred to as a brake controller, controls the actuator for operating the parking brake here. In the operation of the motor vehicle, in particular of the device, a functional defect of the brake controller, or even a failure of the brake controller, can occur here. In order to continue to ensure the functionality of the parking brake system, it is known from the prior art to use a further controller to operate the actuator in a redundant manner.

[0003] It is known from DE 10 2017 222 484 A1 that, for such a device, two microchips are used in a redundant manner, wherein these microchips can be arranged in a respectively associated controller or in one common controller. It is thus necessary to provide a respective, complete infrastructure for the respective microchips and thus for the respective controllers. When using two microchips in one common controller, this requires an expansion and a supplement of the controller, and when using the microchips in respectively associated controllers, it is necessary to provide two complete controllers respectively.

[0004] The disadvantage of the solutions known from the prior art is in particular the complex infrastructure and the complex and expensive device construction. SUMMARY

[0005] It is therefore an object of the present invention to propose an improved or at least a different embodiment for a device for an automatic parking brake system of the type described above and for a method for operating such a device, which is characterized in particular by a simplified construction and inexpensive production, while the failure safety is high.

[0006] According to the invention, this object is achieved by the subject matter of the independent claims. Advantageous embodiments are the subject matter of the dependent claims.

[0007] The invention is based on the general idea of providing, in a device for an automatic parking brake system, for an actuator of the parking brake system, which is to be operated by means of the device, an associated switching mechanism which selectively connects the actuator to one of two associated control units for operating the actuator. It is thereby possible in a simple manner to operate the actuator by means of the associated switching mechanism using the other control unit in the event of a fault in one of the control units associated with the actuator. This results in an improved failure safety of the device. Furthermore, it is possible in this way to dispense with the use of redundant controllers, in particular controllers which each have a complete, complete infrastructure. As a result, the device is constructed in this way in a simplified manner and is implemented cost-effectively.

[0008] According to the idea of the invention, the device has, for at least one of the actuators to be controlled, preferably for the respective actuator, an associated switching mechanism. The purpose of the switching mechanism is to selectively connect the associated actuator to one of two control units associated with the actuator, so that the actuator is operated in operation by means of the control unit which has the switching mechanism connected to the actuator. Thus, the respective actuator is provided with an associated first control unit and an associated second control unit. Here, the respective switching mechanism can be switched between two positions or states, which are also referred to in the following as primary state and secondary state for better differentiation. Here, in the primary state, the respective switching mechanism connects the associated actuator to one of the associated control units for the operation, for example to the associated first control unit, while in the secondary state, the other of the associated control units is connected, for example the associated second control unit.

[0009] The respective actuator is used in the parking brake system to operate at least one parking brake. In the present case, "operating a parking brake" is to be understood as engaging or locking and releasing the respective parking brake.

[0010] The respective control unit is in particular an output stage. The respective control unit is advantageously designed as a bridge circuit, preferably as an H-bridge. This allows simple and reliable operation of the respective associated actuator.

[0011] The device can have at least one controller which has at least one of the control units.

[0012] In a preferred embodiment, the control unit for actuating at least one of the at least one actuator, advantageously for actuating the respective actuator, is an integral part of the at least one controller. That is to say, the control unit is integrated in particular in the at least one controller. The at least one controller then has two assigned control units for actuating one actuator of the parking brake system, respectively. This leads to a simplified construction of the device and also allows the device to be incorporated in the assigned parking brake system in a simplified manner. In this way, in particular, the electrical connections required outside the at least one controller are reduced.

[0013] The respective switching mechanism is preferably arranged between or interfaces between the assigned actuator and the two assigned control units. The switching mechanism thus switches between the primary state and the secondary state in a simplified manner. Furthermore, this leads to a simplified construction of the device.

[0014] In principle, at least one of the at least one switching mechanism can be arranged arbitrarily in the device. In particular, at least one of the at least one switching mechanism can be arranged outside the at least one controller.

[0015] At least one of the at least one switching mechanism is preferably integrated in at least one of the at least one controller. This leads to a further simplification of the device construction. At least one of the at least one switching mechanism is advantageously integrated in one of the at least one controller. The respective switching mechanism is particularly preferably integrated in one of the at least one controller.

[0016] When integrating the respective switching mechanism in one of the at least one controller, it is possible to use a usual controller as a further controller when using a further controller in the device. This further controller then does not need to be adapted or changed for the purpose of being incorporated in the device. This leads to a corresponding simplified implementation of the device.

[0017] In principle, the device can have one unique controller.

[0018] It is also conceivable for the device to have two controllers. These controllers are also referred to as brake controller and additional controller in the following in order to better distinguish between them.

[0019] The respective controller advantageously has an assigned control unit for the respective actuator. The assigned switching mechanism then connects the assigned control unit of one of the controllers, for example the brake controller, to the assigned actuator in the primary state, and, conversely, the switching mechanism connects the assigned control unit of the other controller, for example the additional controller, to the assigned actuator in the secondary state. This leads to a simplified implementation of the device and further improves the fail safety.

[0020] Advantageously and expediently, the respective controller has, in addition to the at least one control unit assigned thereto, a microprocessor and / or a memory. Preferably, the control logic for actuating the at least one actuator is stored in the memory.

[0021] The respective control logic is stored, for example, as control software, in particular as a computer program product, in the controller assigned thereto.

[0022] Preferably, the complete control logic for actuating the at least one actuator is stored in the brake controller, while a reduced control logic for actuating the at least one actuator is stored in the additional controller. In contrast to the reduced control logic, the complete control logic, for example, also includes a call of the respective current state of the at least one actuator. In contrast thereto, the reduced control logic can contain only instructions for opening and closing the at least one actuator. For example, a reduced control logic for opening and closing the assigned parking brake can actuate the actuator for a defined period of time. In contrast thereto, the complete control logic can take into account the current state of the actuator or of the assigned parking brake when actuating. This enables a simplified provision of the device. Furthermore, in this way it can be achieved that, as brake controller, an already existing brake controller known from the prior art is used. Furthermore, the additional controller can be designed more simply in this respect. The complete control logic, for example, corresponds to the recommendation VDA 305-100 (recommendation for integrating the actuation of electric parking brakes into the ESC controller).

[0023] Here, the respective at least one switching mechanism is expediently arranged outside the brake controller. In this way it can be achieved that, by using a common brake controller, the device with the increased failure safety is provided simply and cost-effectively.

[0024] The brake controller is, for example, an ESP controller of a motor vehicle. As an alternative or in addition, the brake controller can be an IPB controller of a motor vehicle. In particular, the brake controller does not need a further adaptation, as described above. This leads to the said simplified implementation of the device.

[0025] The additional controller is preferably a vehicle controller of the motor vehicle assigned thereto. The said vehicle controller is used, for example, for controlling the drive of the motor vehicle assigned thereto in addition to actuating the actuator. A controller already present in the motor vehicle is then used as additional controller. Thus, a further simplified and cost-effective implementation of the device is given, while the failure safety is increased.

[0026] The device is advantageously designed in such a way that the respective switch mechanism is connected to the associated actuator. For example, at least one electrical connection for connecting the switch mechanism to the associated actuator can be provided for the respective switch mechanism.

[0027] The device is advantageously designed in such a way that the respective control unit is connected to the associated switch mechanism. In particular, at least one electrical connection can be provided for connecting the respective control unit to the associated switch mechanism.

[0028] If the device has two controllers, it is preferred that the controllers are communicatively connected to one another. This communication connection can take place here wirelessly or by means of at least one electrical connection. Here, the communication connection of the controllers is preferably independent of the actuation of the at least one actuator. This means that the communication connection of the controllers is independent of the existing electrical connections between the respective switch mechanism and the associated control unit and between the respective switch mechanism and the associated actuator. It is thus possible in a simple and reliable manner to identify possible faults in the respective controller and / or to report the fault to the other controller with increased reliability.

[0029] At least one of the at least one switch mechanisms, advantageously the respective switch mechanism, preferably has only two switches. This leads to a simplified implementation of the device while increasing the failure safety.

[0030] For the device, by means of the respective switch mechanism, in the event of a fault or failure of one of the associated control units, it is advantageously switched into a state in which the switch mechanism connects the associated actuator to the other control unit. In other words, if a fault or failure occurs in one of the control units, the switch mechanism connects the actuator to the other control unit associated with the actuator, if necessary by switching. In this way, the failure safety of the device and / or the parking brake system is improved while simplifying the implementation of the device.

[0031] It goes without saying that, in addition to the device, a method for operating the device also falls within the scope of the present application. Here, as described above, in the event of a fault in one of the control units, the associated switch mechanism is switched into a state in which the associated actuator is actuated by the other associated control unit. It goes without saying here that no switching takes place if the actuator is already connected to the other control unit without a fault in the current state of the switch mechanism.

[0032] If the device has two controllers, the device can be operated as follows during the start-up process of the device, in particular of the parking brake system or of the motor vehicle to which it is assigned. During the start-up process, the additional controller, in particular the vehicle controller, is first started up. Furthermore, the respective switch mechanism is switched to the secondary state, if this is not already the case. This means that the respective switch mechanism connects the respective actuator to the respectively assigned additional control unit. Here, the operational readiness of the respective actuator can be checked by the additional controller. Then or during this, the brake controller can be started up. The start-up of the brake controller can be carried out by the additional controller via the communication connection. Furthermore, the respective switch mechanism can be switched to the primary state. With the respective switch mechanism switched to the primary state, the parking brake system is operated with the brake controller. If the function of the additional controller fails, the function of the parking brake system is still ensured by the brake controller.

[0033] In the communication between the controllers, a fault can occur. In this case, the respective at least one switch mechanism can either be switched to the primary state or to the secondary state. Since the probability of a double fault, that is to say a fault in the communication and a fault in one of the control units, is relatively low, a high level of failure safety of the device, in turn of the parking brake system, is still achieved. It is preferred here that the respective at least one switch mechanism is operated or switched to a state in which the assigned actuator is controlled by the assigned control unit of the brake controller, in particular by the control unit of the controller with the complete control logic.

[0034] If a fault occurs in the communication between the controllers and two switch mechanisms are provided for each assigned actuator, it is alternatively possible to switch one of the switch mechanisms to or to operate it in the primary state and to switch the other switch mechanism to or to operate it in the secondary state. For a complete failure of the device or of the parking brake system, it is certain here that a fault occurs both in the communication and in the respective control unit. Since this is very unlikely, the failure safety of the device, in turn of the parking brake system, is further improved.

[0035] It goes without saying that, in addition to the device and the method, the motor vehicle to which it is assigned also falls within the scope of the present application.

[0036] The motor vehicle comprises, in addition to the device, at least one actuator and, for the respective actuator, at least one assigned parking brake.

[0037] Further important features and advantages of the present application result from the dependent claims, the drawings and the associated description of the drawings by means of the drawings.

[0038] It is self-evident that the features mentioned above and still to be explained below can be used not only in the combinations given, but also in other combinations or alone, without leaving the scope of the present application.

[0039] Preferred embodiments of the present application are shown in the drawings and will be described in more detail below in the description of the application, in which the same reference notations have been used to represent the same or similar or functionally similar components. BRIEF DESCRIPTION OF DRAWINGS

[0040] Preferred embodiments of the present application are shown in the drawings and will be described in more detail below in the description of the application, in which the same reference notations have been used to represent the same or similar or functionally similar components.

[0041] wherein the following is shown schematically:

[0042] Figure 1 is a very simplified circuit diagram of a motor vehicle having an automatic parking brake system and a device for the automatic parking brake system, the device being in a first state of the device;

[0043] Figure 2 is a flow chart for introducing the operation of the device. Figure 1 is a view in another state of the device;

[0044] Figure 3 is a flow chart for introducing the operation of the device. DETAILED DESCRIPTION

[0045] The device 1 for operating an automatic parking brake system according to the present application, as it is exemplarily shown in Figure 1 and 2The device 1 is shown as a component of a motor vehicle 2, which comprises a parking brake system, not shown. The device 1 is used to actuate at least one actuator 3 of the parking brake system, wherein the actuator 3 actuates at least one associated parking brake, not shown, of the parking brake system. In the shown embodiment, the device 1 has two actuators 3 of the parking brake system, namely a first actuator 3a for actuating a first parking brake and a second actuator 3b for actuating a second parking brake. The device 1 has two associated control units 9, 10 for the respective actuator 3, which are used to control the associated actuator 3. In the shown embodiment, the device 1 has at least one controller 4, 5 for actuating at least one actuator 3 and thus has at least two control units 9, 10. In the shown embodiment, the device 1 has two controllers 4, 5. One of the controllers 4 is referred to in the following as a brake controller 4 and the other controller 5 is referred to as an additional controller 5. The brake controller 4 is preferably an ESP controller 6 or an IPB controller 7 of the motor vehicle 2. The additional controller 5 is preferably a vehicle controller 8, which is used, in addition to actuating the actuators 3, for example, to actuate a drive mechanism, not shown, of the motor vehicle 2. In the shown embodiment, the respective controller 4, 5 has an associated control unit 9, 10 for the respective actuator 3, by means of which an actuation signal can be output to the associated actuator 3. This means that the brake controller 4 has a first control unit 9a for actuating the first actuator 3a and a second control unit 9b for actuating the second actuator 3b. The control units 9 of the brake controller 4 are also referred to in the following as brake control units 9, respectively. In a similar manner, the additional controller 5 has a first control unit 10a for actuating the first actuator 3a and a second control unit 10b for actuating the second actuator 3b. The control units 10 of the additional controller 5 are also referred to in the following as additional control units 10, respectively.

[0046] In order to transmit the actuation signals to the associated actuators 3, the device 1 has, in the shown embodiment, at least one associated electrical line 11, 12 for the respective control unit 9, 10, which is also referred to in the following as a control line 11, 12, respectively. In the shown embodiment, two associated control lines 11, 12 are provided for the respective control unit 9, 10. As a result, the device 1 has two first brake control lines 11a for the first brake control unit 9a and two second brake control lines 11b for the second brake control unit 9b. Furthermore, the device 1 has two first additional control lines 12a for the first additional control unit 10a and two second additional control lines 12b for the second additional control unit 11b.

[0047] The device 1 has an assigned switching mechanism 13 for the respective actuator 3. This means that, in the shown embodiment, the device 1 has a first switching mechanism 13a for the first actuator 3a and a second switching mechanism 13b for the second actuator 3b. The respective switching mechanism 13 is connected with the assigned actuator 3 using at least one assigned electrical control line 14, which is also referred to as output control line 14 in the following, respectively. In the shown embodiment, the respective switching mechanism 13 has two separate switches 15. Furthermore, two assigned electrical output control lines 14 are provided for the respective switching mechanism 13. This means that, in order to actuate the first actuator 3a, two first output control lines 14a electrically connect the first switching mechanism 13a or the assigned each switch 15 of the first switching mechanism 13a with the first actuator 3a. Furthermore, in order to actuate the second actuator 3b, two second output control lines 14b electrically connect the second switching mechanism 13b or the assigned each switch 15 of the second switching mechanism 13b with the second actuator 3b. The first switching mechanism 13a is thus assigned or attributed to the first actuator 3a as well as to the first brake control unit 9a and to the first additional control unit 10a. Analogously, the second switching mechanism 13b is assigned or attributed to the second brake control unit 9b and to the second additional control unit 10b.

[0048] The respective switching mechanism 13 is adjustable between a primary state 16, which is shown in Figure 1 , and a secondary state 17, which is shown in Figure 2 . Here, purely exemplary, both switching mechanisms 13 are shown in Figure 1 in the primary state 16, while both switching mechanisms 13 are shown in Figure 2 in the secondary state 17. It goes without saying, however, that these switching mechanisms 13 can be switched between the primary state 16 and the secondary state 17 independently of one another, respectively.

[0049] In the primary state 16, the respective switching mechanism 13 connects the assigned actuator 3 with the assigned brake control unit 9, so that the actuator 3 is actuated in operation by the assigned brake control unit 9 and thus by the brake controller 4. In contrast, the respective switching mechanism 13 in the secondary state 17 establishes a connection between the assigned actuator 3 and the assigned additional control unit 10, so that the assigned actuator 3 is actuated by the assigned additional control unit 10 and thus by the additional controller 5.

[0050] In the embodiment shown, the respective switching mechanism 13 is provided in the additional controller 5. It is thus possible to use a common brake controller 4 as brake controller 4 without special adaptations. The brake control line 11 then runs from the brake controller 4 to the additional controller 5, and the additional control line 12 runs inside the additional controller 5. Furthermore, the output control line 14 runs from the additional controller 5 to the respectively assigned actuator 3.

[0051] The respective controller 4, 5 advantageously has, in addition to the control unit 9, 10, a microchip and a memory, which are shown combined as a switching system 18, 19 in the respective controller 4, 5. In this regard, the brake controller 4 comprises the assigned switching system 18, and the additional controller 5 comprises the assigned switching system 19. The respective switching system 18 is advantageously connected to the assigned control unit 9, 10.

[0052] The respective control unit 9, 10 is, for example, an electrical output stage 20. The respective control unit 9, 10 is preferably a bridge circuit 21, advantageously an H-bridge 22.

[0053] Furthermore, in the embodiment shown, a communication connection 23, which is shown in the figures in dashed lines, is provided between the controllers 4, 5, independently of the control lines 11, 12, 14. This can be an electrical connection 23 and / or a wireless connection 23.

[0054] In the memory of the respective switching system 18, 19, advantageously a control logic, for example in the form of software or a computer program product, for operating the actuator 3 is stored. In this regard, in the embodiment shown, the complete control logic, i.e. in particular the control software according to the VDA 305-100 recommendation, is stored in the memory of the brake controller 4. In this regard, in the memory of the additional controller 5, a reduced control logic, i.e. in particular a reduced software version, is stored. While the control logic of the brake controller 4 enables complete operation and monitoring of the actuator 3, the control logic of the additional controller 5 enables, for example, only a defined time of energization of the actuator 3 and / or an overall energization.

[0055] The motor vehicle 2 and the device 1 can be operated according to the flowchart shown in Figure 3

[0056] ​In the starting process 24 of the motor vehicle 2, the additional controller or the vehicle controller 8 is first of all activated here. Furthermore, the respective switch mechanism 13 is switched into the secondary state 17, if this is not already the case. The respective actuator 3 is checked here by means of the additional controller 5 or the vehicle controller 8. Furthermore, the brake controller 4 is activated, for example by means of the additional controller 5, in particular by means of the communication connection 23. The function of the control units 9, 10 and the connection 23 is then checked in the checking process 25.

[0057] If all control units 9, 10 are fault-free, the respective switch mechanism 13 is switched into the primary state 16 in the regulating operation 26, so that the actuator 3 is operated by the brake controller 4. The method then returns to the checking process 25.

[0058] If it is established in the checking process 25 that one of the brake control units 9 is faulty, the switch mechanism 13 assigned to the brake control unit 9 is switched into the secondary state 17 or is kept in the secondary state 17 in the first emergency operation 27, so that the associated actuator 3 is operated by means of the associated additional control unit 10 and thus with the additional controller 5. Thus, if, for example, the first brake control unit 9a is established as faulty, the first switch mechanism 13a is switched into the secondary state 17 or is kept in the secondary state 17, so that the first actuator 3a is operated by means of the first additional control unit 10a and thus with the additional controller 5. At the same time, a fault message indicating this fault can be generated and stored. The vehicle driver can be requested to visit a repair shop here. The method can then return to the checking process 25.

[0059] If it is established in the checking process 25 that one of the additional control units 10 is faulty, the switch mechanism 13 assigned to the additional control unit 10 is switched into the primary state 16 or is kept in the primary state 16 in the second emergency operation 28, so that the associated actuator 3 is operated by means of the associated brake control unit 9 and thus with the brake controller 4. Thus, if, for example, the first additional control unit 10a is established as faulty, the first switch mechanism 13a is switched into the primary state 16 or is kept in the primary state 16, so that the first actuator 3a is operated by means of the first brake control unit 9a and thus with the brake controller 4. At the same time, a fault message can be generated and stored. This fault message can be read out on the next visit to a repair shop and the error cause of the respective additional control unit 10 can be eliminated. The method can then return to the checking process 25.

[0060] If a fault in the communication connection 23 between the controllers 4, 5 is ascertained in the checking process 25, the respective switch mechanism 13 can be switched in a third emergency operation 29 into the primary state 16 or the secondary state 17 or remain in the respective state 16, 17. This means that in the third emergency operation 29 the actuators 3 are operated by means of the brake control unit 9 and thus with the brake controller 4 or by means of the additional control unit 10 and thus with the additional controller 5. The switch mechanism 13 is preferably switched into the primary state 16 or remains in the primary state 16, so that the actuators 3 are operated by the brake controller 4. As an alternative, in the third emergency operation 29 one of the switch mechanisms 13 can be switched into the primary state 16 or remain in the primary state 16, whereas the other switch mechanism 13 is switched into the secondary state 17 or remains in the secondary state 17. In this way, one of the actuators 3 is operated by the brake controller 4 and the other actuator 3 is operated by the additional controller 5. In the third emergency operation, moreover, a fault message can be generated and stored. This fault message can be read out at the next visit to the repair shop and the error cause can be eliminated. The method can then return to the checking process 25.

Claims

1. A device (1) for controlling at least one actuator (3) of an automatic parking braking system of a motor vehicle (2). - in, The device (1) has a first control unit (9) and a second control unit (10) associated with the corresponding at least one actuator (3). - wherein the device (1) has a corresponding switching mechanism (13) for the corresponding at least one actuator (3). - Wherein, the corresponding switching mechanism (13) is capable of switching between a primary state (16) and a secondary state (17), - In order to operate, the corresponding switching mechanism (13) connects the associated actuator (3) to the associated first control unit (9) in the primary state (16), and connects to the associated second control unit (10) in the secondary state (17). The brake controller (4) to which the first control unit (9) belongs stores a complete control logic device for controlling the actuator (3), and the auxiliary controller (5) to which the second control unit (10) belongs stores a reduced control logic device for controlling the actuator (3).

2. The apparatus as claimed in claim 1, characterized in that, - The device (1) has at least two controllers; - Each of the at least two controllers has a control unit for operating the at least one actuator (3).

3. The apparatus as described in claim 2, characterized in that, At least one switching mechanism (13) is integrated into the brake controller (4) or an additional controller (5).

4. The apparatus as described in claim 2 or 3, characterized in that, - The device (1) has two controllers, namely a braking controller (4) and an auxiliary controller (5).

5. The apparatus as described in claim 4, characterized in that, The brake controller (4) and the additional controller (5) are communicatively interconnected independently of the operation of at least one actuator (3).

6. The apparatus according to any one of claims 1 to 3, characterized in that, At least one switching mechanism (13) has only two switches (15).

7. A method for operating the apparatus according to any one of claims 1 to 6, wherein, When one of the control units malfunctions, the associated switching mechanism (13) is switched to the following state (16, 17), in which the associated actuator (3) is operated by means of another associated control unit.

8. The method as described in claim 7, characterized in that, During the startup process of the device (1): - Start the additional controller (5); - Switch the corresponding switching mechanism (13) to the secondary state (17), and have the additional controller (5) check the operational readiness of the actuator (3); - Activate the brake controller (4), and when no fault is detected on the brake controller (4), switch the corresponding switching mechanism (13) to the primary state (16).

9. The method as described in claim 7 or 8, characterized in that, Using the apparatus (1) according to claim 5, and when the communication connection fails: - Switch the corresponding switching mechanism (13) to the primary state (16) or the secondary state (17); or - Switch one of the switching mechanisms (13) to the primary state (16) and switch the other switching mechanism (13) to the secondary state (17).

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