Brake system for motor vehicle, method for operating brake system

Abstract

The invention relates to a brake system of a motor vehicle and a method for operating the brake system. The invention relates to a brake system for a motor vehicle (1), comprising at least two, in particular four, independently controllable brake actuators, in particular hydraulic or electromechanical brake actuators (4-1, 4-2, 4-3, 4-4), for decelerating the motor vehicle (1). According to the invention, at least one sensor (7-1, 7-4) is provided, which is assigned to exactly one of the brake actuators (4-1, 4-2, 4-3, 4-4), in particular arranged thereon, and the brake actuators (4-1, 4-2, 4-3, 4-4) are each designed to be actuated in accordance with a sensor signal of the at least one sensor (7-1, 7-4).

Description

Technical Field

[0001] The invention relates to a brake system for a motor vehicle, which has at least two, in particular four, brake actuators, in particular hydraulic or electromechanical brake actuators, which can be controlled independently of one another for decelerating the motor vehicle. The invention also relates to a method for operating such a brake system. Background Art

[0002] From the prior art, brake systems of the type mentioned above are known, in which at least one separate sensor is associated with each brake actuator, wherein the brake actuator is each designed to be controlled as a function of the sensor signal of the sensor. Thus, a separate sensor is provided for each brake actuator, wherein the sensor signal of the sensor is used only for the respective brake actuator. Summary of the invention

[0003] The brake system according to the invention is characterized by at least one sensor, which is assigned to exactly one of the brake actuators, in particular arranged thereon, wherein the brake actuators are each designed to be controlled according to the sensor signal of at least one sensor. Thus, the complexity of the brake system is advantageously reduced compared to the above-described solutions, because the number of sensors is reduced. Preferably, the brake system has exactly one, i.e. only one, such sensor. In this simplest case, a single sensor is sufficient to control all brake actuators. Preferably, the sensor values ​​of the sensor are sent to a computer device for this purpose, which is arranged in the brake system in particular as a central computer device, or is arranged remotely from the brake system in a decentralized manner, for example based on the cloud. Particularly preferably, the brake system is designed as a brake-by-wire system, and therefore has no mechanical connection to the brake pedal of the motor vehicle. In particular, the brake system is designed as a purely electromechanical brake system (EMB) without hydraulic components. For example, at least one sensor is designed as a temperature sensor. Particularly preferably, two or at least two of the four brake actuators, in particular two brake actuators, in particular on the same axle, are structurally identical. For example, two purely electromechanical, especially identical brake actuators are provided on one axle, and two hydraulic, especially identical brake actuators are provided on another axle. For example, at least one of the brake actuators has an electric motor for generating a braking force and / or a brake pressure.

[0004] According to a preferred development of the invention, at least two such sensors are provided. This ensures particularly advantageous redundancy. Preferably, all sensors measure the same physical variable, for example temperature or pressure, or at least measure a variable which represents the same physical variable but is in particular different, for example electrical. Particularly preferably, the sensors have different measuring principles and / or accuracies, thereby advantageously increasing robustness and / or reducing costs. In particular, the sensor signals of the sensors are compared with one another in order to detect a fault in one of the sensors.

[0005] It is particularly preferred that the sensors are respectively assigned to different brake actuators, in particular arranged thereon. This assignment or arrangement of the sensors has the advantage of further increasing the robustness of the brake system, because, for example, in the event of a communication failure of a sensor with one of the brake actuators, the other sensors remain unaffected.

[0006] According to a preferred development of the invention, it is provided that the sensor or at least one of the sensors is a temperature sensor for detecting the temperature of the brake actuator. The advantages of the brake system according to the invention are particularly evident in the case of a design as a temperature sensor. The temperature sensor can advantageously be installed in any type of brake actuator. Preferably, the temperature sensor is designed to output the temperature of the brake actuator or at least a specific component of the brake actuator and / or a temperature estimate of the brake actuator or its component, for example to a computer device specially designed for receiving and / or evaluating these sensor signals. For example, a predetermined temperature model is used to predict the temperature estimate within a predetermined time period.

[0007] It is particularly preferably provided that the sensor or at least one of the sensors is a pressure sensor for detecting the hydraulic pressure of the respective hydraulic brake actuator. The design as a pressure sensor provides a particularly advantageous possibility of use for the brake system according to the invention. A pressure sensor is required if at least one of the brake actuators has a hydraulic component. Preferably, a temperature sensor is provided as an additional sensor or as part of a common sensor arrangement.

[0008] According to a preferred refinement of the invention, at least one computer device, in particular a control device, is provided, which is specially designed to receive sensor signals from at least one of the sensors and / or to actuate at least one of the brake actuators in accordance with the corresponding sensor signals. The computer device configured in this way advantageously ensures that the brake actuators are reliably actuated.

[0009] It is particularly preferred that the computer device is assigned to at least one, in particular exactly one, of the sensors and / or brake actuators or is assigned as a central computer device to a plurality, in particular all, of the sensors and / or brake actuators. By being assigned to one of the sensors and / or brake actuators, the flexibility in the control and evaluation of the sensor signals is advantageously increased. By being assigned to a plurality of the sensors and / or brake actuators, a simple central control structure is advantageously provided. It is particularly preferred that at least two computer devices are assigned to each sensor and / or brake actuator, in particular redundantly.

[0010] According to a preferred development of the invention, it is provided that the computer device is designed to convert the sensor signal into an adaptation signal for the brake actuator and to control the brake actuator according to the adaptation signal, or to send the adaptation signal to at least one further computer device, which is assigned to at least one of the brake actuators for controlling the brake actuator. The adaptation signal advantageously ensures that the brake actuator is precisely controlled. For example, the adaptation signal contains a change in the braking force, a change in the brake pressure and / or a corresponding degradation concept of the brake actuator, in particular a limitation of the force increase dynamics or the pressure increase dynamics, the maximum braking force and / or the control pressure.

[0011] It is particularly preferred that the computer device is connected or connectable to at least one of the sensors, the brake actuator and / or the further computer device in terms of communication technology wirelessly, in particular via a radio connection and / or wiredly, in particular via a vehicle bus, for example a CAN bus. Such a communication connection advantageously ensures a particularly flexible and stable data exchange. In particular, at least two communication connections, for example a wireless and a wired communication connection, are provided redundantly. In particular, the sensor, the brake actuator and / or the computer device are integrated into a communication connection that is present in the motor vehicle anyway.

[0012] The method according to the invention for operating a brake system according to the invention is characterized in that the brake actuator is respectively actuated as a function of the sensor signal of the sensor. This provides a particularly advantageous use possibility for the brake system. Preferably, the sensor or at least one of the sensors is designed as a temperature sensor and / or a pressure sensor. For example, a stored temperature model and / or a pressure-volume characteristic curve is taken into account in the actuation.

[0013] According to a preferred development of the invention, at least two sensors are provided, wherein a sensor is selected according to a predefined criterion assigned or assignable to the sensor, and the brake actuator is actuated according to the sensor signal of the sensor. Such a sensor selection advantageously ensures that the brake actuator is actuated in each case according to the best available sensor signal. For example, the sensors are respectively assigned to different brake actuators, so that the respective brake actuator can be actuated in each case according to its own or other sensors.

[0014] It is particularly preferably provided that the criterion comprises the availability of the sensor signal, in particular the delay time and / or the availability of the sensor communication connection. This advantageously further increases the robustness of the method according to the invention.

[0015] According to a preferred development of the invention, it is provided that the criterion includes the signal quality of the sensor, the measurement uncertainty and / or the measurement principle. This advantageously maximizes the accuracy in controlling the brake actuator. For example, the temperature behavior of the corresponding brake actuator is checked and / or predicted with the aid of the criterion.

[0016] It is particularly preferred that, in addition to the sensor signal, at least one further information item is taken into account during the actuation, in particular the effective power, the pressure build-up characteristic and / or the installation position of the respective brake actuator. This consideration of information results in the advantage that the state of the brake actuator is taken into account during the actuation of the brake actuator. For example, the wear state of the respective brake actuator is taken into account, in particular with the aid of a correspondingly predefined wear model. Preferably, the temperature behavior of the respective brake actuator is checked and / or predicted with the aid of the information, in particular in combination with the above-mentioned criteria.

[0017] According to a preferred development of the invention, it is provided that the sensor signal is converted into an adaptation signal for the brake actuator and the brake actuator is actuated according to the adaptation signal. The adaptation signal advantageously ensures that the brake actuator is actuated in a targeted manner. As described above, the adaptation signal includes in particular a change in the brake pressure, the braking force and / or a degradation concept of the brake actuator. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Further preferred features and feature combinations result from the above description and the claims.

[0019] The present invention is explained in detail below with the aid of the accompanying drawings.

[0020] Figure 1 A first embodiment of an advantageous braking system is shown,

[0021] Figure 2 A second embodiment of a braking system is shown, and

[0022] Figure 3 A method for operating a brake system is shown. DETAILED DESCRIPTION

[0023] Figure 1 A motor vehicle 1 is shown having a first embodiment of an advantageous brake system 2 installed therein. A minimal solution is shown with regard to the components used and the interconnections.

[0024] The brake system 2 thus has at least two, in the present case four, brake actuators 4-1, 4-2, 4-3 and 4-4 which can be controlled independently of one another for decelerating the motor vehicle 1. Here, the brake actuators are respectively assigned to different wheels of the motor vehicle 1, i.e. the brake actuator 4-1 is assigned to the left front wheel 3-1, the brake actuator 4-2 is assigned to the right front wheel 3-2, the brake actuator 4-3 is assigned to the left rear wheel 3-3, and the brake actuator 4-4 is assigned to the right rear wheel 3-4.

[0025] In the present case, brake actuators 4-1, 4-2 are assigned to the front axle 5 of the motor vehicle 1, and brake actuators 4-3, 4-4 are assigned to the rear axle 6 of the motor vehicle 1. The brake system 2 can of course be expanded to any number of axles. The brake actuators 4-1 to 4-4 are in particular designed as hydraulic brake actuators or purely electromechanical brake actuators. Preferably, the brake actuators on at least one axle are designed identically.

[0026] In the present case, the sensor 7-1 is associated with the brake actuator 4-1, in particular, it is arranged on the brake actuator, and the sensor is in particular configured as a temperature sensor for detecting the temperature of the brake actuator 4-1 and / or a pressure sensor for detecting the hydraulic pressure of the brake 4-1. At least the brake actuators 4-1, 4-2 of the front axle 5 are configured to be controlled according to the sensor signal of the sensor 7-1.

[0027] For this purpose, the brake system 2 has a computer device 8-1 designed as a control device or control unit (ECU), which is designed to receive sensor signals from the sensor 7-1 and to control the brake actuators 4-1, 4-2 at least according to the corresponding sensor signals. This is shown by the corresponding arrows shown in solid lines. In the present case, the computer device 8-1 is arranged in the brake actuator 4-1. According to another embodiment not shown, the computer device 8-1 is arranged outside the brake actuator 4-1 and is in particular designed as a central computer device.

[0028] Optionally, the brake actuators 4 - 3 , 4 - 4 are also included in the control, as indicated by the corresponding dashed arrows. This means that the brake actuators 4 - 3 , 4 - 4 are preferably also designed to be controlled by the computer device 8 - 1 as a function of the sensor signal of the sensor 7 - 1 .

[0029] Figure 2 A motor vehicle 1 is shown which has a second exemplary embodiment of a brake system 2 which is expanded, in particular with regard to advantageous redundancy, and which is based on the first exemplary embodiment.

[0030] In addition to the above-mentioned components, each brake actuator 4-1 to 4-4 also has a corresponding computer device 8-1 to 8-4. In addition, a further sensor 7-4, which is currently assigned to the brake actuator 4-4, is also provided. In particular, the sensor 7-4 is constructed identically to the sensor 7-1 at least in terms of the physical variable to be detected, and alternatively, the sensor 7-4 differs from the sensor 7-1 in its functional principle and / or its accuracy, for example.

[0031] Finally, a central computer device 9 is provided, which is designed to communicate with each computer device 8-1 to 8-4 in order to selectively control the corresponding brake actuator 4-1 to 4-4 according to the sensor signal of the sensor 7-1 or the sensor 7-4. For example, the computer device 9 is designed to send an adaptation signal to the computer devices 8-1 to 8-4. Optionally, a further computer device (not shown) is provided as redundancy for the computer device 9.

[0032] The computer devices 8-1 to 8-4 and 9 and / or the sensors 7-1, 7-4 are integrated into a common communication network, for example, wired or wirelessly. As can be seen from the corresponding arrows, the communication connection is clearly established, so that the computer devices 8-1 to 8-4 and 9 can communicate with each other and / or with other components of the motor vehicle 1, not shown, respectively.

[0033] In this regard, Figure 2 Shows the Figure 1 It is to be understood that from the complexity it is also conceivable that Figure 1 and Figure 2 The embodiment not shown, for example, only supplemented by the sensor 7-4 or at least one of the computer devices 8-2 to 8-4 Figure 1 .

[0034] Then, refer to Figure 3 An advantageous method for operating the brake system 2 is described. To this end, Figure 3 The method is illustrated with the aid of a flow chart. In particular, the method ensures that brake system 2 is optimally actuated as a function of the available sensor signals.

[0035] In step S1 , the method begins with the receipt and / or evaluation of sensor signals of sensors 7 - 1 and / or 7 - 4 by at least one of the computer devices 8 - 1 to 8 - 4 or 9 . Figure 1In the first exemplary embodiment shown, the sensor signal of the sensor 7 - 1 is received and evaluated, for example, by the computer device 8 - 1 . The method then continues with step S3 .

[0036] For example, in Figure 2 In the second exemplary embodiment shown, the sensor signals of the two sensors 7 - 1 , 7 - 4 are received and evaluated by the computer device 9. The method then continues with step S2.

[0037] In step S2, one of the sensors 7-1, 7-4 is selected based on criteria that are or can be assigned to the sensors 7-1, 7-4, and the method continues with step S3. The criteria include, in particular, the availability of the sensor signal, for example, the delay time and / or availability of the sensor communication connection, the signal quality of the sensor, the measurement uncertainty and / or the measurement principle.

[0038] In step S3, at least the brake actuators 4-1 and 4-2 are actuated as a function of the sensor signal of the sensor 7-1, or all brake actuators 4-1 to 4-4 are actuated as a function of the sensor signal of the selected sensors 7-1, 7-4. Further information is preferably taken into account in this case. The further information includes in particular the effective power, the pressure increase characteristic and / or the installation position of at least one of the brake actuators 4-1 to 4-4.

[0039] Optionally, the sensor signal is converted into an adaptation signal, for example for the computer device 8 - 1 to 8 - 4 , before the actuation, for example by the computer device 9 , and the brake actuators 4 - 1 to 4 - 4 are actuated according to the adaptation signal. The method then ends or begins again with step S1 .

Claims

1. A braking system (2) for a motor vehicle (1), comprising at least two, in particular four, independently controllable brake actuators (4-1, 4-2, 4-3, 4-4), in particular hydraulic or electromechanical brake actuators, for decelerating the motor vehicle (1), characterized in that: A method of dismantling the brake actuator and the control device is provided with at least one sensor (7-1, 7-4), which is assigned to exactly one of the brake actuators (4-1, 4-2, 4-3, 4-4), and is particularly arranged on the exactly one brake actuator, wherein the brake actuators (4-1, 4-2, 4-3, 4-4) are respectively constructed to be controlled according to a sensor signal of the at least one sensor (7-1, 7-4).

2. The braking system according to claim 1, characterized in that: At least two such sensors (7-1, 7-4) are provided.

3. The braking system according to claim 2, characterized in that: The sensors (7-1, 7-4) are respectively associated with different brake actuators (4-1, 4-2, 4-3, 4-4), in particular are arranged thereon.

4. A braking system according to any one of the preceding claims, characterised in that The sensor (7-1, 7-4) or at least one of the sensors (7-1, 7-4) is a temperature sensor for detecting the temperature of the brake actuator (4-1, 4-2, 4-3, 4-4).

5. A braking system according to any one of the preceding claims, characterised in that The sensor (7-1, 7-4) or at least one of the sensors (7-1, 7-4) is a pressure sensor for detecting the hydraulic pressure of the corresponding hydraulic brake actuator (4-1, 4-2, 4-3, 4-4).

6. A braking system according to any one of the preceding claims, characterised in that It has at least one computer device (8-1, 8-2, 8-3, 8-4, 9), in particular a control device, which is specially designed to receive sensor signals from at least one of the sensors (7-1, 7-4) and / or to control at least one of the brake actuators (4-1, 4-2, 4-3, 4-4) based on the corresponding sensor signals.

7. The braking system according to claim 6, characterized in that: The computer device (8-1, 8-2, 8-3, 8-4) is assigned to at least one, in particular exactly one, of the sensors (7-1, 7-4) and / or the brake actuators (4-1, 4-2, 4-3, 4-4), or as a central computer device (9) is assigned to a plurality, in particular all, of the sensors (7-1, 7-4) and / or the brake actuators (4-1, 4-2, 4-3, 4-4).

8. The braking system according to claim 6 or 7, characterized in that: The computer device (9) is configured to convert the sensor signal into an adaptation signal for the brake actuator (4-1, 4-2, 4-3, 4-4) and to control the brake actuator (4-1, 4-2, 4-3, 4-4) according to the adaptation signal, or to send the adaptation signal to at least one other computer device (8-1, 8-2, 8-3, 8-4), which is assigned to at least one of the brake actuators (4-1, 4-2, 4-3, 4-4) to control the at least one brake actuator.

9. The brake system according to any one of claims 6 to 8, characterized in that: The computer device (8-1, 8-2, 8-3, 8-4, 9) is connected or can be connected wirelessly, in particular via a radio connection and / or wiredly, in particular via a vehicle bus, such as a CAN bus, to at least one of the sensors (7-1, 7-4), the brake actuator (4-1, 4-2, 4-3, 4-4) and / or the other computer device (8-1, 8-2, 8-3, 8-4, 9) in terms of communication technology.

10. A method for operating a brake system (2) according to any one of claims 1 to 9, characterized in that: The brake actuators (4-1, 4-2, 4-3, 4-4) are respectively controlled according to the sensor signals of the sensors (7-1, 7-4).

11. The method according to claim 10, characterized in that At least two sensors (7-1, 7-4) are provided, wherein a sensor (7-1, 7-4) is selected according to a predetermined criterion assigned or assignable to the sensors (7-1, 7-4), and the brake actuator (4-1, 4-2, 4-3, 4-4) is controlled according to the sensor signal of the sensor.

12. The method according to claim 11, characterized in that The criteria include the availability of the sensor signal, in particular the latency and / or availability of the sensor communication connection.

13. The method according to claim 11 or 12, characterized in that: The criteria include the signal quality, the measurement uncertainty and / or the measurement principle of the sensors (7-1, 7-4).

14. The method according to any one of claims 10 to 13, characterized in that In addition to the sensor signal, at least one further item of information is taken into account during the actuation, in particular the effective power, the pressure buildup characteristic and / or the installation position of the respective brake actuator (4-1, 4-2, 4-3, 4-4).

15. The method according to any one of claims 10 to 14, characterized in that The sensor signal is converted into an adaptation signal for the brake actuator (4-1, 4-2, 4-3, 4-4), and the brake actuator (4-1, 4-2, 4-3, 4-4) is actuated as a function of the adaptation signal.

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