Sensor components for vehicles

Abstract

The invention relates to a sensor assembly (1) for a vehicle, comprising a sensor element (WSS) for detecting a measured variable and at least two controllers (ECU1, ECU2), wherein the controllers respectively have a measuring circuit (MS1, MS2) and a power supply (VB1, VB2), wherein a first terminal (WSS1) of the sensor element (WSS) is connected to a power supply (VB1) of a first controller (ECU1) of the at least two controllers (ECU1, ECU2), and a second terminal (WSS2) of the sensor element (WSS) is connected to a ground terminal (GND) via a measuring circuit (MS1, MS2) of a second controller (ECU2) of the at least two controllers (ECU1, ECU2), wherein a sensor current (Is) flowing through the sensor element (WSS) is modulated using information about the detected measured variable, wherein the measuring circuit (MS1) of the first controller (ECU1) evaluates the power supply (VB1) and the sensor current (GND) of the sensor element (WSS). A sensor current (Is) detected in a high-side path between a sensor element (WSS) and a ground terminal (GND) is detected in a second measurement circuit (MS2) of a second controller (ECU2), and a first emergency protection circuit (20A) is arranged in parallel with the low-side path and monitors a voltage drop (U12) at a second terminal (WSS2) of the sensor element (WSS), wherein when the voltage drop (U12) reaches a predetermined breakdown voltage value (UK), the first emergency protection circuit (20A) provides an alternative low-side path for the sensor element (WSS) and receives the sensor current (Is), so that at least the first measurement circuit (MS1) can continue to evaluate the detected sensor current (Is), wherein the first emergency protection circuit (20A) also reduces the voltage drop (U12) to a holding voltage value (UH) less than the breakdown voltage value (UK).

Description

Technical Field

[0001] The present invention relates to a sensor assembly for a vehicle. Background Art

[0002] Sensor assemblies for vehicles are known from the prior art, which have a wheel sensor with at least one sensor element for each wheel. The individual wheel sensors are usually connected via a two-wire twisted pair to a controller for a vehicle braking system, which, for example, implements an ABS, ESP, ASR and / or hill-holding function (ABS: anti-lock braking system, ESP: electronic stability program, ASR: drive slip control). Usually, a first terminal of at least one sensor element is connected to a power supply via the controller (high-side path), and a second terminal of at least one sensor element is connected to ground via the controller (low-side path). The sensor current flowing through the at least one sensor element is modulated with information about the number of revolutions and / or rotational speed of the corresponding wheel, wherein an evaluation and control unit of the controller evaluates the sensor current detected between the at least one sensor element and ground.

[0003] From DE 10 2016 222 628 A1, a sensor assembly with a sensor for detecting a measured variable is known, comprising: a first evaluation unit with a first measuring resistor, to which a sensor signal of the sensor representing the measured variable is fed to generate a measured voltage drop; a second evaluation unit with a second measuring resistor, to which a sensor signal of the sensor representing the measured variable is fed to generate a measured voltage drop; a first voltage source connected to the first evaluation unit; a second voltage source connected to the second evaluation unit; and a switching device, which is connected to the sensor and is designed so that in the event of a failure of one evaluation unit, a measured voltage drop can be generated across the measuring resistor of the other evaluation unit. In addition, the sensor is connected to the first voltage source on the voltage side via the first measuring resistor and to ground on the ground side via the second measuring resistor. In this case, a first diode-Zener diode combination is connected in parallel with the first measuring resistor, and a second diode-Zener diode combination is connected in parallel with the second measuring resistor, wherein the first and second diode-Zener diode combinations are each designed to have a breakdown voltage greater than the measured voltage drop, so that in the event of a failure of the evaluation unit, the relevant diode-Zener diode combination can be caused to break down. Furthermore, a further first diode-Zener diode combination can be provided, which is arranged between the sensor and the second voltage source. Furthermore, one end of the second diode-Zener diode combination can be connected to a ground terminal of the second evaluation unit, and the further second diode-Zener diode combination can be connected to a ground terminal of the first evaluation unit. Summary of the invention

[0004] The advantage of the sensor assembly for vehicles with the features according to the present invention is that the first emergency protection circuit monitors the low-side path and provides an alternative low-side path without current detection for the sensor element in the event of failure of the low-side path, so that at least one first measuring circuit can continue to evaluate the detected sensor current. When the voltage drop at the second measuring terminal of the sensor element exceeds a breakdown voltage value that can be preset, for example, in the range of 2.0V to 4.0V, the first emergency protection circuit is activated. The activated first emergency protection circuit limits the voltage drop at the second measuring terminal of the sensor element to a holding voltage value in the range of about 0.8V to 1.5V and can withstand a sensor current of up to 50mA. Therefore, compared with a pure Zener diode structure, the emergency protection circuit of the emergency protection circuit according to the present invention has a significantly smaller voltage drop in the activated state when the load current is similar.

[0005] The embodiment of the present invention provides a sensor unit for a vehicle, comprising a sensor element for detecting a measured variable and at least two controllers, the controllers respectively having a measuring circuit and a power supply. The first terminal of the sensor element is connected to the power supply of the first controller of the at least two controllers, and the second terminal of the sensor element is connected to the ground terminal via the measuring circuit of the second controller of the at least two controllers. Here, the sensor current flowing through the sensor element is modulated using information about the measured variable detected, wherein the measuring circuit of the first controller evaluates the sensor current detected in the high-side path between the power supply and the sensor element, and the second measuring circuit of the second controller simultaneously evaluates the sensor current detected in the low-side path between the sensor element and the ground terminal. In addition, the first emergency protection circuit is arranged in parallel with the low-side path and monitors the voltage drop at the second terminal of the sensor element. The first emergency protection circuit provides an alternative low-side path for the sensor element, and receives the sensor current when the voltage drop reaches a predetermined breakdown voltage value, so that at least the first measuring circuit can continue to evaluate the detected sensor current. In addition, the first emergency protection circuit reduces the voltage drop to a holding voltage value less than the breakdown voltage value.

[0006] In addition, such a sensor assembly for a vehicle has the following advantages: the sensor signals of the individual sensor elements are provided via a tap between the power supply and the sensor element in the first controller (high-side path) and via a tap between the sensor element and the ground terminal in the second controller (low-side path), so that they can be evaluated simultaneously by two evaluation and control units. For this purpose, the measuring circuit of the first evaluation and control unit of the first controller evaluates the sensor current detected in the high-side path, and the second measuring circuit of the second evaluation and control unit of the second controller simultaneously evaluates the sensor current detected in the low-side path. Only a simple sensor element is used for each measuring point, and its sensor signal is redundantly evaluated by the two controllers, thereby significantly reducing costs compared to using two sensor elements for each measuring point, while the reliability of the redundant evaluation is approximately the same, because the sensor signals of all measuring points are evaluated in both controllers and the probability of failure of the sensor elements is very low.

[0007] Typically, an embodiment of the sensor assembly according to the present invention may include a plurality of sensor elements, which are distributedly arranged at corresponding measuring points in the vehicle. Thus, the embodiment of the sensor assembly herein may preferably be used in a vehicle braking system. In such a braking system, the measuring points may, for example, be respectively assigned to a wheel, wherein the corresponding sensor element may detect at least one revolution and / or rotation speed of the assigned wheel. Of course, the sensor elements may also be arranged at other measuring points in the vehicle. In addition, the sensor elements may also detect other measured variables, such as temperature, pressure, etc.

[0008] Here, the evaluation and control unit can be understood as a circuit for processing or evaluating the detected sensor signal. The evaluation and control unit can have an interface that can be constructed based on hardware and / or software. In a hardware-based construction method, the interface can be, for example, a part of the various functions of the so-called ASIC system containing the evaluation and control unit. And it is also feasible that the interface is an integrated circuit of itself or is at least partially composed of discrete components. In a software-based construction method, the interface can be, for example, a software module coexisting on a microcontroller with other software modules. It is also advantageous to have a computer program product with a program code, which is stored on a machine-readable carrier such as a semiconductor memory, a hard disk memory or an optical memory, and is used to perform the evaluation when the evaluation and control unit runs the program.

[0009] In this context, a controller is understood to be an electrical device such as a brake controller, which can be combined with a hydraulic brake system to perform various braking functions, such as ABS, ESP, ASR and / or a hill hold function (ABS: Anti-lock Braking System, ESP: Electronic Stability Program, ASR: Drive Slip Control). In this context, the two controllers can perform different braking functions in normal operation. In the event of a failure of one of the controllers, it can be provided that the other controller takes over the braking function of the failed controller.

[0010] Here, a sensor element can be understood as an electrical device which detects a physical variable or a change in a physical variable directly or indirectly in the area of ​​the assigned wheel and preferably converts it into an electrical sensor signal. This can be done, for example, by sending and / or receiving sound waves and / or electromagnetic waves and / or by a magnetic field or a change in a magnetic field. Optical sensor elements can be used, which, for example, have light plates and / or fluorescent surfaces and / or semiconductors that detect the impact or intensity, wavelength, frequency, angle, etc. of the received waves, such as infrared sensor elements. Acoustic sensor elements, such as ultrasonic sensor elements and / or high-frequency sensor elements and / or radar sensor elements and / or sensor elements that respond to magnetic fields, such as Hall sensor elements and / or magnetoresistive sensor elements and / or inductive sensor elements, which, for example, record changes in the magnetic field by means of a voltage generated by magnetic induction, can also be considered.

[0011] The sensor arrangement for a vehicle can be advantageously improved by means of the measures and developments listed below.

[0012] It is particularly advantageous that the first emergency protection circuit can automatically disconnect the alternative low-side path again if the voltage drop drops below a switch-off voltage value that is less than the holding voltage value due to an external event. For example, the drop in voltage drop may be caused by the initial low-side path having been reactivated and available again.

[0013] In an advantageous embodiment of the sensor assembly, a second emergency protection circuit, whose mode of action corresponds to that of the first emergency protection circuit, can be arranged in parallel with the high-side path and monitors the voltage drop at the first terminal of the sensor element. Here, when the voltage drop reaches a predetermined breakdown voltage value, the second emergency protection circuit can provide an alternative high-side path for the sensor element and receive the sensor current, so that at least the second measuring circuit can continue to evaluate the detected sensor current. In addition, the second emergency protection circuit reduces the voltage drop to a holding voltage value that is less than the breakdown voltage value. In addition, if the voltage drop drops to a switch-off voltage value that is less than the holding voltage value due to an external event, the second emergency protection circuit can automatically disconnect the alternative high-side path again. For example, the switch-off voltage value can be preset in the range of 0.4V to 0.7V.

[0014] In another advantageous embodiment of the sensor assembly, the corresponding emergency protection circuit can include a voltage detector and a current sink. Here, the voltage detector drives the current sink so as to establish a current path between the terminals of the corresponding emergency protection circuit. In addition, the voltage detector can detect a voltage drop between a first terminal and a second terminal of the corresponding emergency protection circuit and drive the current sink when the detected voltage drop reaches a predetermined breakdown voltage value. In addition, the current sink can set the voltage drop across the transistor to a predetermined holding voltage value and receive the sensor current.

[0015] In another advantageous embodiment of the sensor assembly, when the voltage drop rises, the voltage detector can be combined with the overvoltage protector to drive the current sink so that the sensor current can be reduced to a minimum current or completely switched off. This will advantageously protect the current sink from excessive currents or excessive total power losses, which could otherwise lead to damage to the current sink and the corresponding emergency protection circuit.

[0016] In a further advantageous embodiment of the sensor arrangement, the voltage detector can terminate the driving of the current sink and interrupt the current path again when the detected voltage drops below a predetermined switch-off voltage value.

[0017] In another advantageous design of the sensor assembly, the current sensor can detect the sensor current in the high-side path and divide a portion of the sensor current and provide it as a first measurement current to a first measuring circuit of the first controller. Here, the second measuring circuit of the second controller can receive and evaluate the sensor current directly as a second measurement current. The current sensor can, for example, be circulated into the current path and divide a portion of the sensor current and pass the remaining sensor current to the sensor element. As a result, the sensor current flowing into the first terminal of the corresponding sensor element is measured and an equivalent but significantly smaller portion of the sensor current is passed to the first measurement circuit. Power losses in the first controller can thereby be reduced.

[0018] In another advantageous embodiment of the sensor assembly, the switching device can connect the first terminal of the sensor element to the first power supply and / or the second power supply, wherein the switching device can automatically connect the first terminal of the sensor element to the other power supply in the event of a failure of the connected power supply. In addition, the current sensor and the switching device can be combined in an interconnection module, which can be implemented as an ASIC module. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Embodiments of the present invention are shown in the accompanying drawings and explained in detail in the following description. In the accompanying drawings, the same reference numerals represent components or elements that perform the same or similar functions. Among them:

[0020] Figure 1 A schematic block diagram of a first embodiment of a sensor assembly for a vehicle according to the present invention is shown.

[0021] Figure 2 A schematic block diagram of a second embodiment of a sensor assembly for a vehicle according to the present invention is shown.

[0022] Figure 3 A schematic block diagram of a third embodiment of a sensor assembly for a vehicle according to the present invention is shown.

[0023] Figure 4 A schematic block diagram of a fourth embodiment of a sensor assembly for a vehicle according to the present invention is shown.

[0024] Figure 5 Shows Figures 1 to 4 FIG. 1 is a schematic block diagram of an embodiment of an emergency protection circuit for a sensor assembly of a vehicle according to the present invention.

[0025] Figure 6 Shows Figure 5 Circuit diagram of the emergency protection circuit in.

[0026] Figure 7 Shows Figure 5 and Figure 6 Schematic current-voltage diagram of the emergency protection circuit in. DETAILED DESCRIPTION

[0027] As from Figures 1 to 6It can be seen that the illustrated embodiments of the sensor assembly 1, 1A, 1B, 1C, 1D for a vehicle according to the present invention respectively include a sensor element WSS for detecting a measurement variable and at least two controllers ECU1, ECU1A, ECU1B, ECU1C, ECU1D, ECU2, ECU2A, ECU2B, ECU2C, ECU2D, and the controllers respectively have measurement circuits MS1, MS2 and power supplies VB1, VB2. Here, the first terminal WSS1 of the sensor element WSS is connected to the power supply VB1 of the first controller ECU1, ECU1A, ECU1B, ECU1C, ECU1D, ECU2, ECU2A, ECU2B, ECU2C, ECU2D of at least two controllers ECU1, ECU1A, ECU1B, ECU1C, ECU1D, ECU2, ECU2A, ECU2B, ECU2C, ECU2D, and the second terminal WSS2 of the sensor element WSS is connected to the ground terminal GND via the measurement circuits MS1, MS2 of the second controller ECU2, ECU2A, ECU2B, ECU2C, ECU2D of at least two controllers ECU1, ECU1A, ECU1B, ECU1C, ECU1D, ECU2, ECU2A, ECU2B, ECU2C, ECU2D. The sensor current Is flowing through the sensor element WSS is modulated using information about the detected measurement variable, wherein the first measurement circuit MS1 of the first controller ECU1, ECU1A, ECU1B, ECU1C, ECU1D evaluates the sensor current Is detected in the high-side path between the power supply VB1 and the sensor element WSS, and the second measurement circuit MS2 of the second controller ECU2, ECU2A, ECU2B, ECU2C, ECU2D simultaneously evaluates the sensor current Is detected in the low-side path between the sensor element WSS and the ground terminal GND. In addition, the first emergency protection circuit 20A is arranged in parallel with the low-side path and monitors the voltage drop U12 at the second terminal WSS2 of the sensor element WSS. The first emergency protection circuit 20A provides an alternative low-side path for the sensor element WSS and is activated when the voltage drop U12 reaches Figure 7 The sensor current Is is received at the predetermined breakdown voltage value UK shown in FIG. 1 , so that at least the first measuring circuit MS1 can continue to evaluate the detected sensor current Is. In addition, the first emergency protection circuit 20A reduces the voltage drop U12 to Figure 7 The holding voltage value UH shown is smaller than the breakdown voltage value UK.

[0028] from Figures 1 to 4It can also be seen that in the illustrated embodiment, the two controllers ECU1, ECU1A, ECU1B, ECU1C, ECU1D, ECU2, ECU2A, ECU2B, ECU2C, ECU2D respectively include an evaluation and control unit 3A, 3B implemented as an ASIC with corresponding measurement circuits MS1, MS2 integrated and a power supply VB1, VB2. Here, in the first controller ECU1, ECU1A, ECU1B, ECU1C, ECU1D, the first evaluation and control unit 3A is connected to the first power supply VB1. In the second control unit ECU2, ECU2A, ECU2B, ECU2C, ECU2D, the second evaluation and control unit 3B is connected to the second power supply VB2.

[0029] Typically, an embodiment of a sensor assembly 1, 1A, 1B, 1C, 1D for a vehicle according to the invention comprises a plurality of measuring points, each of which has such a sensor element WSS. Figure 1 , Figure 2 , Figure 3 and Figure 4 , only one of the sensor elements WSS is shown in each case. Thus, the embodiments of the sensor assemblies 1, 1A, 1B, 1C, 1D shown here are preferably used in vehicle brake systems. In such a brake system, the measuring points can, for example, each be assigned to a wheel, wherein the sensor element WSS can detect at least one number of revolutions and / or rotational speed of the corresponding wheel. Thus, in a normal passenger car with four wheels, the sensor assemblies 1, 1A, 1B, 1C, 1D have four such sensor elements WSS. Of course, other measured variables, such as temperature, pressure, etc., can also be detected at such measuring points.

[0030] In the embodiment shown, when the voltage drop U12 drops below a switch-off voltage value ABS which is less than the holding voltage value UH due to an external event, the first emergency protection circuit 20A automatically disconnects the alternative low-side path again. Figures 5 to 7 The operation mode of the first emergency protection circuit 20A will be described in detail.

[0031] from Figure 1 and Figure 2It can also be seen that in the illustrated embodiment of the sensor assembly 1 according to the invention, a second emergency protection circuit 20B, shown in dashed lines, is optionally provided, which is arranged in parallel to the high-side path and monitors the voltage drop U12 at the first terminal WSS1 of the sensor element WSS. The second emergency protection circuit 20B provides an alternative high-side path for the sensor element WSS and receives the sensor current Is, so that when the voltage drop U12 reaches a predetermined breakdown voltage value UK, at least the second measuring circuit MS2 can continue to evaluate the detected sensor current Is, wherein the second emergency protection circuit 20B additionally reduces the voltage drop U12 to a holding voltage value UH that is less than the breakdown voltage value UK. If the voltage drop U12 drops below a shutdown voltage value ABS that is less than the holding voltage value UH due to an external event, the second emergency protection circuit 20B automatically disconnects the alternative high-side path again.

[0032] The structures and working modes of the two emergency protection circuits are the same. Figures 5 to 7 Let’s explain it in detail together.

[0033] from Figure 5 and Figure 6 It can also be seen that the emergency protection circuits 20A and 20B include a voltage detector 22 and a current sink 24, respectively. Here, the voltage detector 22 drives the current sink 24 to establish a current path between the terminals A1 and A2 of the corresponding emergency protection circuits 20A and 20B. The voltage detector 22 detects a voltage drop U12 between the first terminal A1 and the second terminal A2 of the corresponding emergency protection circuits 20A and 20B, and when the detected voltage drop U12 reaches Figure 7 The current sink 24 is driven at the predetermined breakdown voltage value UK shown. The current sink 24 sets the voltage drop U12 to a predetermined holding voltage value UH and receives the sensor current Is. The characteristic curve is Figure 7 When the voltage drop U12 increases, the voltage detector 22 and the overvoltage protector Combined with the current sink 24, the sensor current Is is reduced to the minimum current or completely shut down. The protection curve SV is Figure 7 When the detected voltage drop U12 is lower than the predetermined shutdown voltage value ABS, the voltage detector 22 stops driving the current sink 24 and interrupts the current path again. Figure 7 Shown by dotted lines.

[0034] from Figure 6It can also be seen that in the embodiment shown, the voltage detector 22 includes a plurality of ohmic resistors R1, R2, R3, R4 and R5, two transistors T1, T2 implemented as bipolar transistors and a Zener diode ZD1, which are connected to each other via corresponding lines as shown in the figure, wherein the first transistor T1 is implemented as a PNP transistor and the second transistor T2 is implemented as an NPN transistor. In the embodiment shown, the current sink 24 includes two ohmic resistors R6 and R7 and two transistors T3 and T4 implemented as bipolar transistors, which are connected to each other via corresponding lines as shown in the figure, wherein both transistors T3 and T4 are implemented as NPN transistors. In the embodiment shown, the overvoltage protector Includes ohmic resistor R8.

[0035] from Figure 6 It can also be seen that the resistors R1, R2 and R6 are the leakage resistances of the bases of the transistors T1, T2 and T3 to keep them cut off and transfer the leakage current. If the current flowing through the Zener diode ZD1 is greater than the current flowing through the second resistor R2, the second transistor T2 is turned on, which turns on the first transistor T1. This is the case in the illustrated embodiment when the applied voltage drop U12 exceeds the breakdown voltage value UK of about 3V. The breakdown voltage value corresponds to the sum of the breakdown voltage (about 2.3V) of the Zener diode ZD1 and the base-emitter voltage (about 0.7V) of the second transistor T2. The first transistor T1 provides current to the base of the second transistor T2 through the fourth resistor R4, so that it continues to remain turned on. The second transistor T2 and the first transistor T1 form a thyristor structure and are bridged on the Zener diode ZD1, so that the voltage drop U12 is set to a holding voltage value UH of about 0.9V. The fourth transistor T4 of the current sink 24 is driven via the fifth resistor R5 and the control line ST, wherein in the embodiment shown the sensor current Is now limited to approximately 40 mA through the fourth transistor T4. In the event of a very high drive current in the control line ST, the third transistor T3 of the current sink 24 receives part of the drive current of the fourth transistor T4 in order to protect it.

[0036] exist Figure 7 In the overvoltage situation, which is shown by the protection curve SV represented by a dotted line and can be triggered, for example, by a short circuit to one of the supply voltages VB1, VB2, if the current supplied to the current sink 24 in this overvoltage situation is greater than the maximum load current of the current sink 24, the current sink 24 can no longer maintain the low holding voltage value UH of the voltage drop U12 of about 0.9 V. Therefore, the current flowing through the overvoltage protector The current of the eighth resistor R8 increases. This causes the third transistor T3 to be turned on to a greater extent and the drive of the fourth transistor T4 is weakened. The current entering the base of the fourth transistor T4 is thereby reduced, and the fourth transistor T4 is further turned off and protected from damage (overload protection). In the event of a short circuit, the fourth transistor T4 can be switched to a cut-off state.

[0037] If, due to an external event, for example due to the reconnection of the original low-side path in the second control unit ECU2, the voltage U12 drops to the switch-off voltage value ABS of about 0.6 V, the thyristor structure composed of transistors T1 and T2 is switched off again. Figure 7 Shown by dotted lines.

[0038] from Figures 1 to 4 It can also be seen that in the embodiment shown, the sensor assembly 1, 1A, 1B, 1C and 1D for a vehicle comprises a current sensor 10, which detects a portion Is / n of the sensor current Is in the high-side path and branches off and provides it as a first measurement current IM1 of a first measurement circuit MS1 of a first controller ECU1, ECU1A, ECU1B, ECU1C, ECU1D. In addition, the current sensor 10 conducts the sensor current Is to a first terminal WSS1 of an associated sensor element WSS. Here, in the embodiment shown, a second measurement circuit MS2 of a second controller ECU2, ECU2A, ECU2B, ECU2C, ECU2D receives the sensor current Is directly as a second measurement current IM2 and evaluates it. The sensor current Is flowing into the first terminal WSS1 of the sensor element WSS is measured by the current sensor 10, and an equivalent but significantly smaller current Is / n is fed to a first evaluation and control unit 3A to reduce power losses in the first controller ECU1, ECU1A, ECU1B, ECU1C, ECU1D. When evaluating the first measurement current IM1 , the first evaluation and control unit 3A takes into account the reduction of the second measurement current that is performed. For this purpose, a corresponding adaptation of the input circuit or the evaluation algorithm of the first measurement circuit MS1 can be performed.

[0039] from Figure 1 It can also be seen that in the illustrated first embodiment of the sensor assembly 1A for a vehicle, the first emergency protection circuit 20A and the optional second emergency protection circuit 20B are each implemented as separate components and are not integrated into one of the two controllers ECU1A, ECU2A. However, in the illustrated first embodiment, the current sensor 10 that detects the sensor current Is in the high-side path and divides off a portion Is / n of the sensor current Is is integrated in the first controller ECU1A.

[0040] from Figure 2It can also be seen that in the illustrated second embodiment of the sensor assembly 1B for a vehicle, the first emergency protection circuit 20A is integrated into the first controller ECU1A. In the illustrated second embodiment of the sensor assembly 1B for a vehicle, the optional second emergency protection circuit 20B is integrated into the second controller ECU2B. Similar to the first embodiment, the current sensor 10 is integrated into the first controller ECU1B.

[0041] from Figure 3 and Figure 4 It can also be seen that in the illustrated embodiment, the sensor assembly 1C, 1D for the vehicle includes a switching device 30, which connects the first terminal WSS1 of the sensor element WSS to the first power supply VB1 of the first controller ECU1C, ECU1D and / or to the second power supply VB2 of the second controller ECU2C, ECU2D. In the event of a failure of the connected power supply VB1, VB2, the switching device 30 automatically connects the first terminal WSS1 of the sensor element WSS to the other power supply VB2, VB1. The switching device 30 preferably connects the first terminal WSS1 of the sensor element WSS to the first power supply VB1 of the first controller ECU1C, ECU1D. If the first power supply VB1 fails, the switching device 30 connects the first terminal WSS1 of the sensor element WSS to the second power supply VB2 of the second controller ECU2C, ECU2D.

[0042] from Figure 3 and Figure 4 It can also be seen that in the illustrated embodiment, the current sensor 10 and the switching device 30 are combined in an interconnection module 40 , which can be embodied as an ASIC module, for example.

[0043] from Figure 3 It can also be seen that in the third embodiment shown of the sensor assembly 1C for a vehicle, the first emergency protection circuit 20A is implemented as a separate component and is not integrated into one of the two controllers ECU1C, ECU2C. The interconnection module 40 is also implemented as a separate component and is not integrated into one of the controllers ECU1C, ECU2C. However, in an alternative embodiment not shown, the first emergency protection circuit 20A can be integrated into the first controller ECU1C similarly to the second embodiment of the sensor assembly 1B.

[0044] from Figure 4It can also be seen that in the fourth embodiment shown of the sensor assembly 1D for a vehicle, the first emergency protection circuit 20A is integrated into the first controller ECU1D. The interconnection module 40 is also integrated into the first controller ECU1D. However, in an alternative embodiment not shown, the first emergency protection circuit 20A can be implemented as a separate component similar to the first and third embodiments of the sensor assembly 1B and is not integrated into the first controller ECU1C.

Claims

1. A sensor assembly (1) for a vehicle, comprising a sensor element (WSS) for detecting a measured variable and at least two controllers (ECU1, ECU2), the at least two controllers (ECU1, ECU2) respectively having a measuring circuit (MS1, MS2) and a power supply (VB1, VB2), wherein a first terminal (WSS1) of the sensor element (WSS) is connected to a power supply (VB1) of a first controller (ECU1) of the at least two controllers (ECU1, ECU2), and a second terminal (WSS2) of the sensor element (WSS) is connected to a ground terminal (GND) via a measurement circuit (MS1, MS2) of a second controller (ECU2) of the at least two controllers (ECU1, ECU2), wherein a sensor current (Is) flowing through the sensor element (WSS) is modulated with information about the detected measured variable, wherein a first measurement circuit (MS1) of the first controller (ECU1) evaluates a sensor current (Is) detected in a high-side path between the power supply (VB1) and the sensor element (WSS), and a second measurement circuit (MS2) of the second controller (ECU2) simultaneously evaluates a sensor current (Is) detected in a low-side path between the sensor element (WSS) and the ground terminal (GND), wherein a first emergency protection circuit (20A) is arranged in parallel with the low-side path and monitors a voltage drop (U12) at a second terminal (WSS2) of the sensor element (WSS), wherein when the voltage drop (U12) reaches a predetermined breakdown voltage value (UK), the first emergency protection circuit (20A) provides an alternative low-side path for the sensor element (WSS) and receives the sensor current (Is), so that at least the first measurement circuit (MS1) can continue to evaluate the detected sensor current (Is), The first emergency protection circuit (20A) further reduces the voltage drop (U12) to a holding voltage value (UH) that is smaller than the breakdown voltage value (UK).

2. The sensor assembly (1) according to claim 1, characterized in that When the voltage drop (U12) drops below a switch-off voltage value (ABS) which is smaller than the holding voltage value (UH) due to an external event, the first emergency protection circuit (20A) automatically disconnects the alternative low-side path again.

3. The sensor assembly (1) according to claim 1 or 2, characterized in that A second emergency protection circuit (20B) is arranged in parallel with the high-side path and monitors a voltage drop (U12) at the first terminal (WSS1) of the sensor element (WSS), wherein when the voltage drop (U12) reaches a predetermined breakdown voltage value (UK), the second emergency protection circuit (20B) provides an alternative high-side path for the sensor element (WSS) and receives the sensor current (Is), so that at least the second measurement circuit (MS2) can continue to evaluate the detected sensor current (Is), wherein the second emergency protection circuit (20B) also reduces the voltage drop (U12) to a holding voltage value (UH) that is smaller than the breakdown voltage value (UK).

4. The sensor assembly (1) according to claim 3, characterized in that When the voltage drop (U12) drops below a switch-off voltage value (ABS) which is smaller than the holding voltage value (UH) due to an external event, the second emergency protection circuit (20B) automatically disconnects the alternative high-side path again.

5. The sensor assembly (1) according to claim 1, characterized in that Each of the emergency protection circuits (20A, 20B) includes a voltage detector (22) and a current sink (24), wherein the voltage detector (22) drives the current sink (24) to establish a current path between terminals (A1, A2) of the corresponding emergency protection circuit (20A, 20B).

6. The sensor assembly (1) according to claim 5, characterized in that The voltage detector (22) detects a voltage drop (U12) between a first terminal (A1) and a second terminal (A2) of a corresponding emergency protection circuit (20A, 20B), and drives the current sink (24) when the detected voltage drop (U12) reaches a predetermined breakdown voltage value (UK).

7. The sensor assembly (1) according to claim 6, characterized in that The current sink (24) sets the voltage drop (U12) to the predetermined holding voltage value (UH) and receives the sensor current (Is).

8. The sensor assembly (1) according to claim 7, characterized in that When the voltage drop (U12) increases, the voltage detector (22) and the overvoltage protector The current sink (24) is driven in combination so that the sensor current (Is) is reduced to a minimum current or is completely shut off.

9. The sensor assembly (1) according to any one of claims 5 to 8, characterized in that When the detected voltage drop (U12) falls below a predetermined switch-off voltage value (ABS) which is smaller than the holding voltage value (UH), the voltage detector (22) stops driving the current sink (24) and interrupts the current path again.

10. The sensor assembly (1) according to claim 1 or 2, characterized in that The sensor element (WSS) detects the number of revolutions and / or rotational speed and / or pressure and / or temperature as measured variables.

11. The sensor assembly (1) according to claim 1 or 2, characterized in that A plurality of sensor elements (WSS) are provided, which are each arranged at a measuring point.

12. The sensor assembly (1) according to claim 11, characterized in that The measuring points are each assigned to a wheel, wherein the corresponding sensor element (WSS) detects at least one number of revolutions and / or rotational speed of the respective wheel.

13. The sensor assembly (1) according to claim 1 or 2, characterized in that A current sensor (10) detects a sensor current (Is) in the high-side path and separates a portion (Is / n) of the sensor current (Is) and provides the portion of the sensor current as a measurement current (IM1) of the first measurement circuit (MS1) of the first controller (ECU1), wherein the second measurement circuit (MS2) of the second controller (ECU2) receives and evaluates the sensor current (Is) directly as a second measurement current (IM2).

14. The sensor assembly (1) according to claim 1 or 2, characterized in that A switching device (30) connects the first terminal (WSS1) of the sensor element (WSS) to a first power source (VB1) and / or a second power source (VB2), wherein the switching device (30) automatically connects the first terminal (WSS1) of the sensor element (WSS) to another power source (VB2, VB1) when a failure occurs in the connected power source (VB1, VB2).

15. The sensor assembly (1) according to claim 13, characterized in that A switching device (30) connects the first terminal (WSS1) of the sensor element (WSS) to a first power source (VB1) and / or a second power source (VB2), wherein the switching device (30) automatically connects the first terminal (WSS1) of the sensor element (WSS) to another power source (VB2, VB1) when a failure occurs in the connected power source (VB1, VB2).

16. The sensor assembly (1) according to claim 15, characterized in that The current sensor (10) and the switching device (30) are combined in an interconnection module (40), which is implemented as an ASIC module.

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