MOTOR VEHICLE BRAKE SYSTEM CONTROLLER AND METHOD

Abstract

A controller for a motor vehicle brake system includes a first functional assembly for controlling a service brake and a second functional assembly for controlling a parking brake. The first and the second functional assemblies can be supplied by separate voltage supplies. The controller is configured in such a way that, in the event of a fault in or affecting the first or the second functional assembly, the respective other functional assembly remains ready for use for at least a defined period of time, and the motor vehicle can be braked by means of the ready-for-use functional assembly within the defined period of time in order to engage a transmission lock of the vehicle and/or in order to hold the vehicle at a standstill using the parking brake.

Claims

1. A controller for a motor vehicle brake system, the controller comprising: a first functional assembly for controlling a service brake; and a second functional assembly for controlling a parking brake; wherein the first and the second functional assemblies may be supplied by separate voltage supplies; wherein the controller is configured that, in the event of a fault in or affecting the first or the second functional assembly, the respective other functional assembly remains ready for use for at least a defined period of time, and the motor vehicle can be braked by the respective other functional assembly within the defined period of time in order to engage a transmission lock of the vehicle and/or in order to hold the vehicle at a standstill using the parking brake.

2. The controller as claimed in claim 1, wherein the first functional assembly and the second functional assembly are separated from each other in such a way that the defined time period of the remaining state of readiness is ensured.

3. The controller as claimed in claim 1, further comprising at least one detection circuit configured to detect an interruption of a supply potential and/or a reference potential of at least one of the power supplies.

4. The controller as claimed in claim 1, wherein at least one of the separate voltage supplies is implemented in a buffered manner in such a way that the particular assigned functional assembly remains suppliable at least for the defined time period.

5. A method to be carried out in a motor vehicle controller which comprises a first functional assembly for controlling a service brake and a second functional assembly for controlling a parking brake, wherein the first and the second functional assemblies can be supplied by separate voltage supplies, wherein that, in the event of a fault in or affecting the first or the second functional assembly, the respective other functional assembly remains ready for use for at least a defined period of time, and the motor vehicle can be braked by the respective other functional assembly within the defined period of time in order to engage a transmission lock of the vehicle and/or in order to hold the vehicle at a standstill using the parking brake.

6. The method as claimed in claim 5, wherein the second functional assembly is monitored by the first functional assembly when both assemblies are in ongoing operation.

7. The method as claimed in claim 5, wherein a control of a parking brake operated by the second functional assembly takes place on demand or when permitted by the first functional assembly.

8. The method as claimed in claim 5, wherein a control of a parking brake operated by the second functional assembly takes place when the first functional assembly permits an automatic control by the second functional assembly or as a consequence of a fault in or affecting the first functional assembly.

9. The method as claimed in claim 5, wherein during an automated parking operation, there is an operation of the parking brake by the second electronic assembly that is independent of the first electronic assembly.

10. A brake system including a controller, the controller comprising: a first functional assembly for controlling a service brake; and a second functional assembly for controlling a parking brake; wherein the first and the second functional assemblies may be supplied by separate voltage supplies; wherein the controller is configured that, in the event of a fault in or affecting the first or the second functional assembly, the respective other functional assembly remains ready for use for at least a defined period of time, and the motor vehicle can be braked by the respective other functional assembly within the defined period of time in order to engage a transmission lock of the vehicle and/or in order to hold the vehicle at a standstill using the parking brake.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Other advantages of the disclosed subject matter will be readily appreciated, as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:

[0019] FIG. 1 shows an exemplary embodiment of a brake system including a functional assembly for operating a service brake and a parking brake with the aid of a voltage supply;

[0020] FIG. 2 shows the brake system including a functional assembly for operating the service brake and the parking brake with the aid of two separate voltage supplies;

[0021] FIG. 3 shows the brake system including a functional assembly for operating the service brake and a functional assembly for operating the parking brake, which are separated from each other and have an independent voltage supplies which can communicate with each other by means of a communication interface;

[0022] FIG. 4 shows the brake system including the functional assembly for operating the service brake and the functional assembly for operating the parking brake, which are separated from each other and have an independent voltage supplies and which can communicate by means of the communication interface, and include a detection circuit for detecting an interruption of the potential or potentials; and

[0023] FIG. 5 shows the functional assembly for operating the parking brake with the aid of an associated supply voltage and an included circuitry part for the autonomous operation of the parking brakes.

DETAILED DESCRIPTION

[0024] Identical elements are provided with identical reference characters in order to allow for a brief and simple description of the exemplary embodiments.

[0025] FIG. 1 shows a brake system 1 including a controller 1.1 which includes a functional assembly G1 for controlling service brake actuators (not shown) and two parking brake actuators or parking brake actuators EPB-L and EPB-R, and which is supplied by a voltage supply U1, GND1. The service brake actuators are not represented in FIGS. 1 to 5, but they are provided in the actual implementation.

[0026] According to one exemplary embodiment, one further voltage supply U2, GND2, which is as independent as possible, is integrated in the vehicle, as shown in FIG. 2, and is also provided, in addition to voltage supply U1, GND1, for supplying controller 1.1 and the functional assembly G1. At least one of the supply voltages can also be implemented in a buffered manner, and so, in the event of failure of this voltage supply for a limited time, a continued operation of the service brake and/or the parking brake is possible by means of the functional assembly G1, e.g., a microprocessor or control unit. The voltage supply U2, GND2 and, optionally, further electrical connections can be transmitted via an additional electrical plug connector or, by way of an appropriate design, via a plug shared with the first voltage supply U1, GND1. The reference potential can be provided via two lines GND1, GND2 or via a shared line when a continued operation of at least one of the brake functions by brake system 1 can be ensured in the event of an interruption of this shared line. A detection of a failure of the reference potential connection or one of the reference potential connections GND1, GND2 and/or the supply potentials U1, U2 is provided.

[0027] According to the refinement of the brake system 1, as shown in FIG. 3, the functional assembly G3 for controlling the parking brake actuators EPB-L, EPB-R is designed separated from the functional assembly G2 for controlling the service brake actuators in such a way that an improved availability can be implemented. The separated assemblies are supplied by an independent voltage supply U1, GND1 or U2, GND2, respectively, wherein implementations—e.g., a shared plug—of the type that were described for the exemplary embodiment according to FIG. 2, can be provided. This separation is designed in such a way that, in the event of a fault that affects at least one of the functional assemblies G2, G3, the respective other functional assembly (having an independent voltage supply) continues to remain operational for a defined time period, e.g., approximately one second, wherein an implementation on a shared circuit board can also be provided. The vehicle can be safely braked in this time period, and so the parking brake or the transmission lock can secure the vehicle. The separated functional assemblies do not necessarily need to be assigned to the same safety integrity level (e.g. ASIL). For example, a design of the functional assembly for controlling the parking brake—in particular also in the HAP operating mode—for a classification into a level that is as high as that of the main processor or the functional assembly for actuating the service brake could be dispensed with.

[0028] Interface L1 is provided for the communication of the functional assemblies G2 and G3. The functional assembly G3 for controlling the parking brake actuators EPB-L, EPB-R essentially takes over all parking brake actuations—even in an HAP operating mode—and, provided the main processor of the controller, which may be included in the functional assembly G2 for controlling the service brakes, is operating, the functional assembly G3 is monitored by this main processor via communication interface L1. Functional assembly G3 therefore monitors functional assembly G2 with respect to faults or interferences that occur.

[0029] According to this configuration, the functional assembly G3 for controlling the parking brake actuators can be secondary (e.g. slave) to the primary functional assembly G2, i.e., hierarchically subordinate thereto in terms of function; according to this example, the primary functional assembly G2 is designed for controlling the service brakes. The activation of the parking brake control may be logically (electronically) locked in such a way that the actuation of the parking brake actuators takes place exclusively when the functional assembly G2 requires or permits this or the HAP operating mode is activated and the functional assembly G3 has been authorized for controlling the parking brake actuators for autonomous operation and/or automatically activates the parking brakes after a detection of a fault of the main processor. This is illustrated according to the functional assembly G3 shown in FIG. 5—for example, for an embodiment of the brake system 1 according to FIG. 3 or FIG. 4—by a circuitry part UC included in this assembly. In this case, the circuitry part UC provides for the (autonomous) operation of the parking brake actuators EPB-L, EPB-R by assembly G3 independently of functional assembly G2. Instead of an additional microprocessor as the secondary assembly, a circuit, e.g. a control unit, can be provided, which is designed for automatically activating the parking brake actuators in the event of a fault of the primary assembly.

[0030] As compared to the embodiment according to FIG. 3, the exemplary embodiment of brake system 1 or of the controller 1.1 according to FIG. 4 additionally comprises the detection circuits GLD for the detection of an interruption of the GND potential or potentials. Alternatively, or in addition, at least one detection circuit can be provided for the detection of an interruption of at least one of the supply potentials (not shown).

[0031] According to another embodiment (not shown), a switch from the primary assembly to the secondary assembly takes place by means of a multiplexer when the HAP operating mode is triggered by the primary assembly or the main processor, so that the secondary assembly can carry out a braking by means of the parking brake actuators in the event of a fault of the primary assembly or the main processor.

[0032] The present disclosure has been described herein in an illustrative manner, and it is to be understood that the terminology which has been used is intended to be in the nature of words of description rather than of limitation. Obviously, many modifications and variations of the invention are possible in light of the above teachings. The invention may be practiced otherwise than as specifically described within the scope of the appended claims.