Sensor module, brake system comprising said sensor module and method for operating said sensor module

Abstract

The present invention relates to a sensor module (4) comprising at least two sensor units (6, 7), a controller (8) configured for regulating the supply voltage for the sensor units (6, 7) and at least one sensor signal output (12), the at least two sensor units (6, 7) being electrically connectable or electrically disconnectable from the controller (8) and electrically connected to the sensor signal output (12), and a first of the sensor units (6) being connected to a second sensor signal output (12) in a standard operation of the sensor module (4). The present invention relates to a sensor module (4) in which a first sensor unit (6) provides a first output signal (13) through the sensor signal output section (12), and a second sensor unit (7) of the sensor units provides a second output signal (14) different from the first output signal (13) through the sensor signal output section (12) in an energy-saving operation of the sensor module (4), and a controller (8) is associated with a determination unit (15) formed for electrically coupling either the first sensor unit (6) or the second sensor unit (7) to the controller (8). [Solution] It is considered that the judgment unit (15) is formed to electrically couple or electrically disconnect the first sensor unit (6) or the second sensor unit (7) to the controller (8) depending on the regulated supply voltage, and that the controller (8) is formed to change the supply voltage at least in the energy saving operation when the output signal (13, 14) provided through the sensor signal output section (12) reaches a predetermined threshold value.

Description

[Technical field]

[0001] The present invention relates to a sensor module comprising at least two sensor units, a controller configured for adjusting the supply voltage to the sensor units, and at least one sensor signal output, the at least two sensor units being electrically connectable or disconnectable from the controller and electrically coupled to the sensor signal output, a first sensor unit among the sensor units providing a first output signal through the sensor signal output in standard operation of the sensor module and a second sensor unit among the sensor units providing a second output signal through the sensor signal output in energy-saving operation of the sensor module, the controller being associated with a determination unit configured for electrically coupling either the first sensor unit or the second sensor unit to the controller.

[0002] The invention further relates to a brake system equipped with a sensor module of this kind.

[0003] Additionally, the present invention relates to a method for operating said sensor module. [Background technology]

[0004] Sensor modules of the type mentioned at the outset are known in principle from the state of the art. For example, EP 1 299 433 A1 discloses a sensor module formed as a microcontroller unit for a motor vehicle, which has a microcontroller associated with at least two sensor units in the form of sensors of the motor vehicle or which is formed for operating these sensors. A first one of the sensor units is formed as a main sensor unit operating in standard operation, which processes various input quantities detected by the sensors and generates at least one first output signal on the basis of this processing. A second one of the sensor units is formed as a standby microcontroller operating in energy-saving operation, which generates at least one second output signal. The first and second output signals are provided via a sensor signal output of the sensor module which is commonly used by both sensor units.

[0005] A voltage source is associated with the sensor module, which is coupled to a controller of the sensor module formed as a current control device, so that a supply voltage provided by the voltage source is available for operating the sensor module via an intermediate connection of the controller. The controller is then formed to electrically couple or electrically disconnect the sensor units to the voltage source, whereby normally only one of the sensor units is always operated. The controller thus also serves as a decision unit formed to electrically couple either the first or the second sensor unit to the voltage source. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] German Patent No. 102012017780B4 Summary of the Invention

[0007] The sensor module with the features of claim 1 has the advantage of having a simple technical design. For this purpose, it is provided according to the invention that the determination unit is designed for electrically coupling or electrically decoupling the first or second sensor unit to the controller depending on the regulated supply voltage, and that the controller is designed for changing the supply voltage at least in energy-saving operation if the output signal provided via the sensor signal output reaches a predefined threshold value. In particular, the controller is designed for changing the supply voltage if the output signal exceeds or falls below a threshold value. That is to say, the selection of which of the two sensor units is to be activated is made depending on the regulated supply voltage, so that the sensor module is designed for controlling the activity of the sensor units by adjusting its supply voltage, which is technically relatively easy to implement. In this respect, no additional communication interfaces or additional signals are required for the activation or deactivation of the sensor units, so that the sensor module, in particular the determination unit and the sensor units, can be designed relatively simply, in particular in terms of communication technology. In addition, the change in supply voltage considered according to the invention ensures a particularly energy-saving operation of the sensor module.

[0008] According to an advantageous further configuration, it is provided that the controller has at least one circuit unit for recognizing the output signal provided via the sensor signal output. This allows the output signal to be recognized and processed by the controller itself, so that no additional, particularly complex evaluation unit is required for this purpose. This further simplifies the configuration of the sensor module. In particular, the circuit unit has a pull-up resistor.

[0009] In particular, the decision unit comprises a circuit with a Zener diode (Z-Diode), a comparator or an operational amplifier, which allows a technically particularly simple construction of the decision unit.

[0010] It is advantageously provided that each sensor unit is provided with a switch, in particular formed as a transistor, which can be controlled by the evaluation unit, and by means of which each sensor unit can be electrically connected to or electrically disconnected from the controller in order to supply the sensor units with a supply voltage, which is advantageous since the electrical connection or disconnection of a number of sensor units can be carried out technically in a particularly simple manner by the controller.

[0011] Preferably, each sensor unit has an open collector output or an open drain output, by means of which the respective sensor unit is electrically coupled to the sensor signal output. This has the advantage that the signal lines associated with the respective inactive sensor units, and in particular the sensor signal output commonly used by the sensor units, are not loaded by the inactive sensor units. Moreover, both sensor units are preferably coupled to the sensor signal output, so that no additional switches, in particular multiplexers, are required. Alternatively, at least one of the sensor units has another disconnectable output, in particular a tri-state output.

[0012] According to a further advantageous embodiment, the second sensor unit is designed as a standby sensor, in particular as a Hall switch, which further simplifies the construction of the sensor module.

[0013] A braking system having the features of claim 7 is characterized in that the sensor module is configured according to the invention as described above, with the advantages mentioned above being obtained in this respect.

[0014] A method for operating a sensor module with the features of claim 8 is characterized in that depending on the adjusted supply voltage, either the first or the second sensor unit is electrically coupled to or electrically decoupled from the controller, and the supply voltage is changed at least in the energy-saving operation if the output signal provided through the sensor signal output reaches a predefined threshold value. The supply voltage is changed in particular if the output signal exceeds or falls below a threshold value. Advantageously, the supply voltage is changed by recognition of the output signal provided through the sensor signal output by a circuit unit of the controller. In particular, a switch, in particular a transistor, associated with the sensor unit and controllable by a decision unit for supplying the sensor unit with a supply voltage is used to electrically couple or decouple the respective sensor unit from the controller. In each case, the advantages already mentioned above are obtained.

[0015] A method for operating a brake system, in particular an above-mentioned brake system, with the features of claim 11 is characterized in that a sensor module is operated according to the above-mentioned method for operating a sensor module, in which the advantages already mentioned are obtained.

[0016] Advantageous features and feature combinations are particularly evident from the foregoing description and the claims.

[0017] Next, the present invention will be described in more detail with reference to the drawings. [Brief description of the drawings]

[0018] [Figure 1] 1 is a highly simplified schematic diagram of an advantageous brake system with an advantageous sensor module; [Diagram 2] 4 is a schematic flow chart of an advantageous method for operating a brake system or a sensor module. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] 1 is a schematic diagram of an advantageous brake system 1 for a motor vehicle, not shown in the figure, in a highly simplified manner. The brake system 1 comprises an electromechanical brake booster 2, which is only illustrated in FIG. 1, an adjustable element 3, which is symbolically illustrated in the figure and is configured as a brake pedal of the motor vehicle, and a sensor module 4. The sensor module 4 serves to control the brake booster 2 on the basis of a displacement of the adjustable element 3 caused by a user of the motor vehicle, thereby generating a braking force for decelerating the motor vehicle. For this purpose, the sensor module 4 is connected to the adjustable element 3, as illustrated by the dashed arrow 5 in FIG. 1, and is configured to control the brake booster 2 depending on the displacement of the adjustable element 3.

[0020] The sensor module 4 comprises, according to the present embodiment, two sensor units 6, 7, which are used in the present embodiment to detect the displacement of the position adjustment element 3. The sensor module 4 further comprises a controller 8, which is formed in the present embodiment for adjusting a supply voltage provided by a voltage source, not shown in FIG. 1, to the sensor units 6, 7. To supply the sensor units 6, 7 with a supply voltage, the sensor units are electrically connected to the controller 8 or can be electrically disconnected therefrom by means of a supply connection 9 and two switches 10, 11, each associated with one of the sensor units 6, 7. The sensor module 4 further comprises a sensor signal output 12, which is commonly used by the sensor units 6, 7, to which both sensor units 6, 7 are always electrically connected. The sensor signal output 12 is also electrically connected to the controller 8 in order to provide output signals 13, 14 generated by the sensor units 6, 7 to the controller 8 for further processing, as will be explained in more detail later.

[0021] In this case, the first sensor unit 6 is formed according to the present embodiment as an operating sensor which is activated during standard operation of the sensor module 4, i.e. which provides a first output signal 13 via the sensor signal output 12 during standard operation. The second sensor unit 7 is formed according to the present embodiment as a standby sensor, in particular as a Hall switch, which provides a second output signal 14 different from the first output signal 13 via the sensor signal output 12 during energy-saving operation of the sensor module 4, in which the first sensor unit 6 is not activated. In this respect, the sensor signal output 12 is advantageously used both for providing the first output signal 13 and for providing the second output signal 14. However, in order to avoid overlapping of the output signals 13, 14 and thus to avoid malfunctions, it is necessary that only one of the sensor units 6, 7 is always active or at least generates the respective output signal. In this respect, one of the switches 10, 11 is always closed, while the other switch 11, 10 is open, so that only one of the sensor units is always supplied with a supply voltage and thus active. To ensure or control this, the sensor module 4 further comprises a determination unit 15, which in particular comprises a circuit with a Zener diode, a comparator or an operational amplifier and is formed for electrically coupling or electrically disconnecting either the first sensor unit 6 or the second sensor unit 7 to the controller 8 by controlling the switches 10, 11.

[0022] In this case, it is advantageously provided that the selection of which of the two sensor units 6, 7 should be electrically coupled to the controller 8 and thus activated is controlled by an adjustment of the supply voltage caused by the controller 8. For this purpose, the decision unit 15 is designed to electrically couple the first sensor unit 6 or the second sensor unit 7 to the controller 8 as a function of the adjusted supply voltage. In this respect, the decision unit 15 is designed to recognize a change in the supply voltage and, based on this, to determine which of the two sensor units 6, 7 should be coupled to the controller 8 or to the supply voltage and thus activated. The corresponding adjustment or change of the supply voltage is also performed by the controller 8 as a function of the output signal 13, 14 provided by the signal output 12, and in particular when the output signal 13, 14 currently provided by the sensor signal output 12 reaches a predefined threshold value. For recognition or evaluation of the corresponding output signal 13, 14, the controller 8 has at least one circuit unit 16, in particular with a pull-up resistor. This allows the controller 8 to know when a certain threshold has been reached and adjust the supply voltage accordingly.

[0023] As already mentioned above, the sensor signal output 12 is used both to provide the first output signal 13 and also to provide the second output signal 14. In order to avoid unnecessary loading of the appropriate signal lines associated with the sensor signal output 12, it is considered according to the present embodiment that the sensor units 6, 7 each have an open drain or open collector output 17, by means of which the sensor units 6, 7 are coupled to the sensor signal output 12. If the voltage level of the open drain or open collector output 17 as the output signal 13, 14 falls below a threshold value, the supply voltage is changed at that time.

[0024] According to this embodiment, the controller 8, the sensor units 6, 7 and the determination unit 15 are not combined, i.e. are formed as separate elements and are connected to each other by means of cables or lines. Optionally, however, at least the determination unit 15 and the sensor units 6, 7 may be arranged on one common circuit board 18, as illustrated by the dashed lines in Fig. 1. In particular, the sensor units 6, 7 and the determination unit 15 are formed on one common semiconductor chip.

[0025] An advantageous method for operating the brake system 1 or its sensor module 4 will now be explained below with the aid of the schematic flow chart shown in FIG.

[0026] The method starts with a first step S1 in which the brake system 1 or the sensor module 4 is in an energy-saving mode. Therefore, at this point, the second sensor unit 7 is activated and the first sensor unit 6 is not activated, in so far as the second switch 11 is closed and the first switch 10 is open, as shown in FIG. 1. Correspondingly, in step S1, the second sensor unit 7 is electrically coupled to the controller 8 and activated by a supply voltage. Now, in a second step S2, the position adjustment element 3 is operated by the vehicle user. This is detected by the second sensor unit 7, which provides the second output signal 14 to the controller 8 by the sensor signal output 12 on the basis of this. In the following step S3, the circuit unit 16 recognizes that the second output signal 14 has reached a predefined threshold value, on the basis of which the controller 8 changes, preferably increases, the supply voltage. As a result, a changed, in particular increased, supply voltage is provided via the supply connection 9. In a next step S4, a change in the supply voltage is recognized by the decision unit 15 and based on this the second switch 11 is opened and the first switch 10 is closed, thereby deactivating the second sensor unit 7 and activating the first sensor unit 6. Based on this, in a further step S5 the first sensor unit 6 detects a further or continuous displacement of the position adjustment element 3 and thus provides a first output signal 13 via the sensor signal output 12 to the controller 8. The first output signal 13 then comprises a protocol for activating the brake booster 2 and is evaluated by the controller 8 in a further step S6. Based on this evaluation, in a next step S7 the brake booster 2 is controlled by the controller 8 or the sensor module 4 in order to realize the user's wish to decelerate, indicated by the operation of the position adjustment element 3, with a braking force. Then, in a further step S8, if a request to switch the brake system 1 back into the energy saving mode is recognized, for example when the user of the vehicle has switched it off or walked away, the first output signal 13 is changed so that it reaches a predefined threshold value, so that the controller 8 recognizes that a new change in the supply voltage should be made.On this basis, in the last step S9, the supply voltage is changed again by the controller 8, in particular decreased, so that the decision unit 15 deactivates the first sensor unit 6 by corresponding control of both switches 10, 11 and reactivates the second sensor unit 7. The method is then started again with step S1. [Explanation of symbols]

[0027] 1 Brake system 2 Brake booster 3 Brake pedal (position adjustment element) 4 Sensor Module 6 First Sensor Unit 7 Second Sensor Unit 8. Controller 10 First Switch 11 Second Switch 12 Sensor signal output section 13 First output signal 14 Second Output Signal 15 Judgment Unit 16 Circuit Unit 17 Open drain output section

Claims

1. A sensor module (4) comprising at least two sensor units (6, 7), a controller (8) configured for regulating a supply voltage for the sensor units (6, 7), and at least one sensor signal output (12), the at least two sensor units (6, 7) being electrically connectable or disconnectable from the controller (8) and electrically connected to the sensor signal output (12), a first sensor unit (6) of the sensor units providing a first output signal (13) via the sensor signal output (12) in a standard operation of the sensor module (4) and a second sensor unit (7) of the sensor units providing a second output signal (14) via the sensor signal output (12) in an energy-saving operation of the sensor module (4).

1. The sensor module (4), in which a controller (8) is provided with a determination unit (15) configured for electrically coupling either the first sensor unit (6) or the second sensor unit (7) to the controller (8), the determination unit (15) being configured for electrically coupling or electrically disconnecting the first sensor unit (6) or the second sensor unit (7) to the controller (8) depending on the regulated supply voltage, and the controller (8) being configured for changing the supply voltage at least in the energy-saving operation if the output signal (13, 14) provided via the sensor signal output (12) reaches a predefined threshold value.

2. 2. The sensor module according to claim 1, characterized in that the controller (8) has at least one circuit unit (16), in particular with a pull-up resistor, for recognizing the output signal (13, 14) provided through the sensor signal output section (12).

3. 10. The sensor module according to claim 1, characterized in that the decision unit (15) comprises a circuit with a Zener diode, a comparator or an operational amplifier.

4. 10. The sensor module according to claim 9, characterized in that each of the sensor units (6, 7) is provided with a switch (10, 11), in particular formed as a transistor, which can be controlled by the decision unit (15), and by means of which each of the sensor units (6, 7) can be electrically connected to or disconnected from the controller (8) in order to supply the sensor units (6, 7) with the supply voltage.

5. 10. The sensor module according to claim 9, wherein the sensor units (6, 7) each have an open collector output, an open drain output (17) or a separately disconnectable output, in particular a tri-state output, by means of which the respective sensor unit (6, 7) is electrically coupled to the sensor signal output (12).

6. 10. The sensor module according to claim 9, characterized in that the second sensor unit (7) is designed as a standby sensor, in particular as a Hall switch.

7. 1. A brake system (1) comprising a brake booster (2), in particular an electromechanical or electrohydraulic brake booster, a position adjustment element (3) displaceable by a user, in particular a brake pedal, and a sensor module (4) associated with the position adjustment element (3) and configured for controlling the brake booster (2) in dependence on the displacement of the position adjustment element (3), characterized in that the sensor module (4) is configured according to one of claims 1 to 6.

8. A method for operating a sensor module having at least two sensor units (6, 7), a controller (8) configured for regulating a supply voltage for the sensor units (6, 7) and at least one sensor signal output (12), the at least two sensor units (6, 7) being electrically connectable or disconnectable from the controller (8) and electrically connected to the sensor signal output (12), the method comprising the steps of: a) providing a first output signal (13) via the sensor signal output (12) in a standard operation of the sensor module (4) and b) providing a second output signal (13) via the sensor signal output (12) in an energy-saving operation of the sensor module (4).

1. The method according to claim 1, wherein a second output signal (14) different from the first output signal (13) is provided via the sensor signal output (12) and a determination unit (15) is associated with the controller (8) which is configured for electrically coupling either the first sensor unit (6) or the second sensor unit (7) to the controller (8), characterized in that the method further comprises the steps of: electrically coupling or electrically disconnecting either the first sensor unit (6) or the second sensor unit (7) to the controller (8) depending on the regulated supply voltage; and varying the supply voltage at least in the energy saving operation if the output signal (13, 14) provided via the sensor signal output (12) reaches a predefined threshold value.

9. 9. The method according to claim 8, characterized in that the supply voltage is varied by recognizing the output signal (13, 14) provided through the sensor signal output (12) by a circuit unit (16) of the controller (8).

10. 10. The method according to claim 8 or 9, characterized in that the respective sensor unit (6, 7) is electrically coupled to or electrically decoupled from the controller (8) by means of a switch (10, 11), in particular a transistor, associated with the sensor unit (6, 7) and controllable by the evaluation unit (15) for supplying the sensor unit (6, 7) with the supply voltage.

11. 11. A method for operating a brake system (1), in particular a brake booster (2), in particular an electromechanical or electrohydraulic brake booster, a position adjustment element (3) displaceable by a user, in particular a brake pedal, and a sensor module (4) associated with said position adjustment element (3), in particular a method for controlling the brake booster (2) by means of the sensor module (4) in dependence on the displacement of the position adjustment element (3), in particular a method for operating the brake system according to claim 7, characterized in that the sensor module (4) is operated according to a method according to any one of claims 8 to 10.

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