Method for operating a braking system of a motor vehicle, braking system

Abstract

To prevent an error message from being generated without a booster control device having received a signal from an engine control device.SOLUTION: Provided is a method for actuating an automobile 1 which has a driving machine 2 with an engine control device 3, and a brake system 5. The brake system includes: a wheel brake 6; and an electromechanical brake booster 7 with a booster control device 9; and a travel stability control device for influencing the brake system in order to stabilize a travel state of the automobile. At the start of use of the brake system, one of these control devices is actuated, and the brake system is monitored with regard to occurrence of error messages. The intention is to start monitoring the engine control device for the first time subsequently to detection of vehicle motion of the automobile.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a method for operating a motor vehicle having at least one drive machine equipped with an engine control device and a brake system, the brake system having at least one wheel brake and at least one electromechanical brake booster equipped with a booster control device, and the motor vehicle having a driving stability control device configured to affect the brake system in order to stabilize the driving state of the motor vehicle, at least one of these control devices being activated at the start of use of the brake system, and the brake system being monitored for the occurrence of error messages.

[0002] Furthermore, the present invention relates to a brake system configured to carry out the above method.

Background Art

[0003] Brake systems and methods for operating them are known from the prior art. A control device is attached to the main components of a motor vehicle. For example, an electromechanical brake booster is operable by a booster control device. A driving stability control device serves, in particular in an emergency, to intervene in the brake system in order to restore or ensure the driving stability of the motor vehicle. This type of booster control device is known, for example, as an ESP control device (ESP = Electronic Stability Program). The booster control device is connected, for example, to a plurality of wheel brakes and individually operates or influences these regardless of the brake request to prevent slip of the motor vehicle, wheel spin of the motor vehicle wheels, or locking. The booster control device controls, for example, the brake booster depending on the brake request and adjusts the hydraulic pressure required for the implementation of the brake request in the brake system. Furthermore, an engine control device is attached to the drive machine of the motor vehicle, and this engine control device is known to control and monitor a drive machine in the form of an internal combustion engine, in particular. For this purpose, a communication network in which the control devices communicate with one another, for example, is monitored with respect to error messages transmitted from one control device to another. Currently, with the start of use of the brake system, the booster control device and the driving stability control device are activated simultaneously, whereby both of these control devices are initialized simultaneously and respective software monitoring is started. However, the engine control device is usually only activated when the ignition of the motor vehicle is operated, so it is still switched off at this point. As a result, for example, the booster control device does not receive a signal from the engine control device, and for this reason an error message is generated, which is registered, for example, in an error memory and / or acoustically or visually notified to the occupants of the motor vehicle. SUMMARY OF THE INVENTION

[0004] The method of the present invention having the constituent features of claim 1 has the advantage that the braking system can be started without generating an error message caused by the engine control device, thereby avoiding the error message. For this purpose, according to the present invention, it is intended that the monitoring of the engine control device is started only subsequent to the detection of the vehicle movement of the motor vehicle. That is, the present invention intends that the monitoring of the engine control device is started only when the vehicle is moving, in particular when driven by the drive machine. Thereby, it is ensured that the engine control device is detected only when the ignition of the motor vehicle is operated and a message of the engine control device can be detected by one of the other control devices. Thereby, at the start of use of the braking system, only the driving stability control device and the booster control device of the three control devices are initialized and checked simultaneously, and thus it is ensured that the error message of the engine control device can be eliminated.

[0005] At the start of use of the braking system, as already described above, it is preferable that the booster control device and the driving stability control device are monitored. In this way, both of these control devices directly attached to the braking system are initialized and monitored with the start of use and inspected for functionality.

[0006] Furthermore, it is preferably intended that the vehicle movement of the motor vehicle is determined depending on the driving speed and / or acceleration of the motor vehicle. Thereby, it is ensured that the ignition of the motor vehicle is operated and the engine control device can be incorporated into the monitoring, and that no error message is generated because the engine control device has not yet been activated. The driving speed and / or acceleration of the motor vehicle is preferably determined by the driving stability control device having one or more acceleration sensors and / or one or more speed sensors or rotational speed sensors, or having access to this type of sensor arranged inside or on the surface of the motor vehicle.

[0007] Furthermore, in order to determine the vehicle movement of the motor vehicle, it is preferably intended that signals from the driving stability control device and / or the engine control device are detected. The driving stability control device supplies, in particular, the signals mentioned above with respect to the driving speed and / or acceleration of the motor vehicle. The engine control device provides, for example, driving signals related to an unambiguous driving operation or a target speed or target acceleration. By means of these, it is possible to check the validity of signals and data provided, for example, by the driving stability control device.

[0008] It is particularly preferred that the start of use of the braking system is initiated depending on the door position of the vehicle door of the motor vehicle. For this purpose, for example, the vehicle door of the motor vehicle is continuously monitored. When it is confirmed that the door is opened or unlocked, the braking system has already started operating, so that when the driver of the motor vehicle sits on the driver's seat, the braking system is already available.

[0009] The braking system according to the invention having the features of claim 6 is characterized in that the booster control device and / or the driving stability control device are specifically set up to carry out the method according to the invention. Optionally, there is a monitoring control device which serves to monitor the existing control devices, namely the driving stability control device, the booster control device, and the engine control device, for malfunctions. In particular, the monitoring control device is configured to monitor a communication network in which the control devices communicate with each other with respect to the occurrence or generation of error messages, and, in particular, is configured to recognize the start of use of the motor vehicle and activate each control device on the basis of the invention. Other advantages and preferred features and combinations of features will become apparent from the above description and the claims.

[0010] In particular, the driving stability control device has at least one acceleration sensor, speed sensor, and / or rotational speed sensor, so that the signals / data mentioned above can be detected.

[0011] The communication network is particularly preferably configured as a BUS system through which each control device communicates with each other.

[0012] Furthermore, it is preferably intended that there is a device for checking the desired start of use of the braking system. In particular, this device is connected to each control device or at least one of each control device and controls it accordingly when the start of use is detected.

[0013] This device is particularly preferably configured as a door lock or door contact. When the position door lock is unlocked or the door contact is opened by the displacement of the vehicle door from the closed position to the open position, as already explained above, the braking system is started by this device.

[0014] Next, the present invention will be described in detail with reference to the drawings.

Brief Description of the Drawings

[0015]

Figure 1

Figure 2

Embodiments for Carrying Out the Invention

[0016] Figure 1 shows a simplified view of a motor vehicle 1 having a drive machine 2 with at least two wheels of the motor vehicle and an internal combustion engine operatively connected for driving them. The internal combustion engine is attached to an engine control device 3 that controls the internal combustion engine, for example, depending on the operation of an accelerator pedal 4. Further, the motor vehicle 1 includes a plurality of wheel brakes 6, each of which has a braking system 5 attached to one of the wheels of the motor vehicle 1, whereby each wheel can be braked individually. Further, the braking system 5 has an electromechanical brake booster 7, a brake pedal 8, and a booster control device 9. The booster control device 9 controls the brake booster 7 to generate a hydraulic pressure by which the wheel brakes 6 are biased depending on the operation of the brake pedal 8 in a hydraulically configured braking system 5. Each wheel brake 6 also has an intake valve and preferably an exhaust valve that can be controlled individually to adjust the brake pressure or brake force for each wheel brake individually using the supplied hydraulic pressure. For this purpose, in particular, there is a driving stability control device 10 that continuously monitors the driving state of the motor vehicle during operation and operates the wheel brakes 6 regardless of the brake force request made to restore or ensure the driving stability of the motor vehicle 1 as necessary.

[0017] The control devices 3, 9, and 10 are connected to each other by a communication network 11 not shown in detail here. The communication network 11 is, for example, a BUS system to which each control device is connected. The control devices 3, 9, and 10 monitor their own operations or the operations of other components, including, for example, the operations of other control devices, for the occurrence of errors and are configured to output error messages distributed or transferred by the communication network 11 when an error is detected.

[0018] Figure 2 shows a flowchart for explaining a preferred method of operating the motor vehicle 1 and in particular the braking system 5.

[0019] In step S1 of this method, for example, the detection of unlocking of the vehicle door of the automobile 1 is started.

[0020] In the subsequent step S2, the optionally provided door contact 12 attached to the vehicle door is monitored for whether the vehicle door is open or not. When this is not the case (n), the process returns to step S1. However, when the door contact operation or the opening of the vehicle door is detected (j), in the subsequent step S3, a start command is output to the control devices 9 and 10 of the brake system 5, whereby these control devices are initialized and start operating. Thus, the start of use of the automobile, or at least the desired or anticipated start of use of the automobile, is determined by the door contact 12. The control devices 9 and 10 are initialized and operate simultaneously. Therefore, the respective control devices for error messages and the program routines for monitoring the automobile also start and proceed simultaneously, although with some difference in degree. When an error message is detected, it is sent into the communication network 11. And in step S4, the error message is evaluated, for example, by a higher-level control device, particularly by the monitoring control device 13 as shown in FIG. 1. When an important error message is issued, for example, a warning message is output to the driver of the automobile 1, and / or optionally, the component of the automobile related to that error message is deactivated or shifted to an emergency operation state.

[0021] Furthermore, in step S5 after the start of use of the control devices 9 and 10, the automobile 1 is monitored for whether an active vehicle movement is being performed. For this purpose, for example, the data of the driving stability control device 10 having access rights to the data of at least one acceleration sensor and / or speed sensor is monitored for whether a reliable vehicle movement of the automobile 1 is being performed, which indicates that the ignition of the automobile 1 is being operated.

[0022] Only when vehicle movement is recognized or determined at (j), in subsequent step S6, the engine control unit also gets involved in monitoring related to error messages. Since the engine control unit 3 is also activated and initialized for the first time when the automobile 1 moves, the error message output from the engine control unit in that case is also important, and it is assumed, for example, that it does not rely on the fact that the engine control unit 3 has not been initialized yet.

[0023] In this way, by a preferred method, it is realized that error messages based on the engine control unit 3 that has not yet been activated or initialized are avoided.

Explanation of Reference Signs

[0024] 1 Automobile 2 Driving machine 3 Engine control unit 5 Brake system 6 Wheel brake 7 Brake booster 9 Booster control unit 10 Driving stability control unit 11 Communication network 12 Door contact

Claims

1. A method of operating a motor vehicle (1) having at least one drive machine (2) and a brake system (5) equipped with an engine control device (3), wherein the brake system (5) has at least one wheel brake (6) and at least one electromechanical brake booster (7) equipped with a booster control device (9), and the motor vehicle has a driving stability control device (10) configured to affect the brake system (5) to stabilize the driving state of the motor vehicle (1), at least one of the booster control device (9) and the driving stability control device (10) is activated at the start of use of the brake system (5), and in a method in which the brake system (5) is monitored for the occurrence of error messages, the monitoring of the engine control device (3) is started only after the vehicle movement of the motor vehicle (1) is detected.

2. The method according to claim 1, characterized in that the booster control device (9) and the driving stability control device (10) are monitored at the start of use of the brake system (5).

3. The method according to claim 1 or 2, characterized in that the vehicle movement of the motor vehicle (1) is determined depending on the vehicle speed and / or acceleration of the motor vehicle (1).

4. The method according to any one of claims 1 to 3, characterized in that signals of the driving stability control device (10) and / or the engine control device (3) are detected for the determination of the vehicle movement of the motor vehicle (1).

5. The method according to any one of claims 1 to 4, characterized in that the start of use of the brake system (5) is started depending on the operating state of the door lock or door contact (12) of the motor vehicle (1).

6. In an automobile (1) having a drive machine (2) to which an engine control device (3) is attached, a braking system (5) having an electromechanical brake booster (7) equipped with a booster control device (9), a driving stability control device (10) configured to affect the braking system (5) in order to stabilize the driving state depending on the current driving state of the automobile (1), and a communication network (11) through which the control devices (3, 9, 10) communicate with each other, the booster control device (9), the driving stability control device (10), and / or yet another control device is configured to implement the method according to any one of claims 1 to 5.

7. The automobile according to claim 6, characterized in that the driving stability control device (10) has at least one acceleration sensor, speed sensor, or rotational speed sensor.

8. The automobile according to claim 6 or 7, characterized in that the communication network (11) is a BUS system.

9. The automobile according to any one of claims 6 to 8, characterized in that there is a device for confirming the start of use of the braking system.

10. The automobile according to claim 9, characterized in that the device is a door lock or door contact (12).

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