Measurement systems for detecting physical parameters and methods for operating measurement systems

Abstract

The proposed solution relates to a measurement system (100) for detecting physical parameters. The measurement system (100) includes a measurement sensor (105) for detecting the physical parameters. The measurement system (100) further includes a first energy supply unit (110) for outputting current or electrical energy to the measurement sensor (105), wherein the first energy supply unit (110, 115) is configured to output the electrical energy to the measurement sensor (105) at a first voltage (U1) relative to a first ground potential (GND1); finally, the measurement system (100) includes a second energy supply unit (115) for outputting current (12) or electrical energy to the measurement sensor (105), wherein the second energy supply unit (115) is configured to output the electrical energy to the measurement sensor (105) at a second voltage (U2) relative to a second ground potential (GND2), wherein the first ground potential (GND1) is different from the second ground potential (GND2). It should be emphasized that the second energy supply unit (115) has a control input (AD) for adjusting the second voltage (U2), wherein the control input (AD) is coupled to the first ground potential (GND1) so as to manipulate the second energy supply unit (115) such that the voltage output by the second energy supply unit (115) to the measuring sensor (105) corresponds to the first voltage (U1) relative to the first ground potential (GND1).

Description

Technical Field

[0001] This invention relates to a measurement system or method. The invention also includes a computer program. Background Technology

[0002] In modern sensor systems, especially those installed in vehicles, it is essential to protect these systems as much as possible from component failure. A common approach is to implement redundant systems or power supply units to power the sensors. These redundant units then take over in case the power supply system fails. However, a problem arises when different power supply systems operate on different ground potentials, resulting in inconsistent voltage supply to the sensors and potentially leading to erroneous measurements when the power supply system is replaced. Summary of the Invention

[0003] Against this backdrop, a measurement system according to the present invention, a method for operating the measurement system, and a corresponding computer program are proposed using the solutions described herein. Advantageous extensions and improvements to the measurement system described herein can be achieved through the measures enumerated in the technical solutions of the invention.

[0004] Therefore, a measurement system for detecting physical parameters is proposed, wherein the measurement system has the following characteristics:

[0005] - A measuring sensor used to detect the physical parameters;

[0006] - A first energy supply unit for outputting current or electrical energy to a measuring sensor, wherein the first energy supply unit is configured to output electrical energy to the measuring sensor at a first voltage relative to a first ground potential;

[0007] - A second energy supply unit for outputting current or electrical energy to a measuring sensor, wherein the second energy supply unit is configured to output electrical energy to the measuring sensor at a second voltage relative to a second ground potential, wherein the first ground potential is different from the second ground potential;

[0008] Its features are,

[0009] The second energy supply unit has a control input for adjusting a second voltage, wherein the control input is coupled to a first ground potential so as to manipulate the second energy supply unit such that the voltage output by the second energy supply unit to the measuring sensor or the voltage applied to the measuring sensor corresponds to a first voltage relative to the first ground potential.

[0010] Physical parameters can be understood as, for example, physical parameters such as rotational speed, acceleration, temperature, or the like. An energy supply unit can be understood as, for example, a unit that provides electrical energy to the measuring sensor in the form of current and / or voltage. Here, the first and second energy supply units may be based on different ground potentials, for example, due to electrical separation or due to long electrical connection lines existing between these ground potentials, which act as resistors and cause the ground potentials to differ from each other. The voltage output by the second energy supply unit to the measuring sensor or applied to the measuring sensor can be understood as a voltage corresponding to the first voltage plus or minus the difference between the first and second ground potentials.

[0011] The proposed solution is based on the understanding that by outputting a second voltage, obtained considering a first voltage or a first ground potential, through a second energy supply unit, the measurement sensor can be supplied via both the first and second energy supply units. The measurement sensor itself receives nearly the same voltage from both the first and second energy supply units and can therefore operate largely without failure. This can also be achieved when the first and second ground potentials are different. Therefore, the second energy supply unit ultimately ensures that the potential difference between the first and second ground potentials is considered or compensated when outputting the second voltage, thereby optimizing the operation or robustness of the measurement sensor. Simultaneously, the measurement sensor can be coupled not only to the first energy supply unit but also simultaneously to the second energy supply unit because, since the essentially same voltage is applied to the measurement sensor from both the first and second energy supply units, fault current does not flow from the first energy supply unit into the second energy supply unit, and vice versa.

[0012] The following implementation of the proposed solution is advantageous: In this implementation, the first energy supply unit has at least one first switch controllable by a first control unit to interrupt the current from the measuring sensor through the first energy supply unit to the first ground potential. Additionally or alternatively, the second energy supply unit may have at least one second switch controllable by a second control unit to interrupt the current from the measuring sensor through the second energy supply unit to the second ground potential. This implementation of the proposed solution offers the advantage that a current path adapted to operating / fault conditions can be actively defined, ensuring a reliable energy supply to the measuring sensor even when a fault or malfunction is detected in one of the energy supply units.

[0013] According to one embodiment of the proposed solution, the first control unit is configured to turn on a first switch when a malfunction of the first energy supply unit is detected. Alternatively or additionally, the second control unit may be configured to turn on a second switch when a malfunction of the second energy supply unit is detected. A malfunction can be understood as, for example, a hardware or software failure, a disconnection, or a similar situation, which at least partially impairs the functionality of the relevant energy supply unit or causes it to malfunction completely. Such an embodiment provides the advantage that, in the event of a malfunction detected in one of the energy supply units, the energy supply to the measuring sensor is suppressed by that energy supply unit, thereby ensuring the most stable and safe possible operation of the measuring sensor.

[0014] Alternatively, the proposed solution can be implemented as follows: In this implementation, the first control unit is configured to close or keep the first switch closed when a functional failure is detected in the second unit. Alternatively or additionally, the second control unit may be configured to close or keep the second switch closed when a functional failure is detected in the first energy supply unit. This implementation offers the advantage of reliably feeding the measurement sensor through the energy supply unit under consideration when a fault is detected in another energy supply unit. In this case, current is fed to the measurement sensor by the energy supply unit under consideration, wherein the current flowing from the measurement sensor also flows through the energy supply unit and may be analyzed to determine if the current contains a code in which physical parameters are encoded by the measurement sensor.

[0015] The following implementation of the proposed solution is particularly advantageous: in this implementation, the measuring sensor is connected in a supply circuit to both a first energy supply unit and a second energy supply unit such that the second energy supply unit supplies current to the measuring sensor and draws current from the measuring sensor to the first energy supply unit, particularly wherein the measuring sensor is switched on in the supply circuit during normal operation. This implementation of the proposed solution offers the advantage that by using two different energy supply units simultaneously, a very robust and secure supply of electrical energy, current, or voltage to the measuring sensor can be guaranteed.

[0016] According to another embodiment of the scheme proposed herein, the second energy supply unit may have a shunt resistor, through which current flows from the second energy supply unit to the measurement sensor during normal operation. This embodiment offers the advantage that, particularly when encoding the physical parameter with different, variable current intensities controlled by the measurement sensor, the value of the physical parameter can be read or transmitted with remarkable technical simplicity.

[0017] The following implementation of the proposed solution is also advantageous: in this implementation, the measuring sensor is configured to encode values ​​representing physical parameters into Manchester code. This implementation offers the advantage of enabling the transmission of measured values ​​for physical parameters detected by the measuring sensor with technical simplicity and low circuit overhead.

[0018] According to another embodiment of the scheme presented herein, the second energy supply unit may also have a switching element connected to a control input terminal, the switching element being configured to control a second voltage based on the voltage difference between the supply voltage powering the second energy supply unit and the first ground potential. This embodiment offers the advantage of particularly simple implementation or control of the second voltage in relation to the first ground potential, such that the second voltage can be output in such a way that the second voltage is provided taking into account the first voltage and the potential difference between the first and second ground potentials.

[0019] The following implementation of the proposed solution is also advantageous: in this implementation, the first energy supply unit and / or the second energy supply unit have at least one voltage regulator, particularly the voltage regulator being implemented as a low-dropout longitudinal regulator. This implementation offers the advantage of making the determination or provision of the first and / or second voltages very simple in terms of technical requirements.

[0020] According to one particular embodiment, the measuring sensor can also be configured as a rotational speed sensor, particularly for detecting the rotational speed of vehicle components and / or the rotational speed of the vehicle's wheels. Such an embodiment of the proposed solution offers the advantage of ensuring reliable and robust measurement of physical parameters, especially in environments with high safety requirements.

[0021] According to one embodiment of the scheme proposed herein, a method for operating a measurement system of a variant of the scheme proposed herein is also proposed, wherein the method includes the following steps:

[0022] - Supply electrical energy to the measuring sensor from the first energy supply unit and / or the second energy supply unit;

[0023] - The measurement signal is output by the measuring sensor, which represents the physical parameter.

[0024] By implementing the method in this way, the above advantages can also be achieved technically simply, so that the physical parameter can be used with high safety and robustness in different environmental scenarios.

[0025] It is also advantageous to have a computer program product or computer program with program code, which can be stored on a machine-readable carrier or storage medium, such as a semiconductor memory, a hard disk memory or an optical memory, and especially when the program product or program is executed on a computer or device, the program code is used to implement, realize and / or manipulate the steps of the method according to one of the foregoing embodiments. Attached Figure Description

[0026] Embodiments of the solutions presented herein are shown in the accompanying drawings and described in more detail in the following description. The accompanying drawings show:

[0027] Figure 1 A block diagram showing an embodiment of the measurement system described herein in a connection structure for normal operation;

[0028] Figure 2 A flowchart is shown as an embodiment of the scheme proposed herein as a variation of the method for running the measurement system described herein. Detailed Implementation

[0029] In the following description of advantageous embodiments of the invention, the same or similar reference numerals are used for elements shown in different figures that serve similar functions, wherein repeated descriptions of these elements are omitted.

[0030] Figure 1A block circuit diagram of one embodiment of the measurement system 100 described herein is shown in the connection structure (Verschaltung) for normal operation. The measurement system 100 includes a measurement sensor 105 to which electrical energy is fed from a first energy supply unit 110 and / or from a second energy supply unit 115, for robust and minimally disruptive supply. The measurement sensor 105 may be configured, for example, as a sensor for a physical parameter, such as the rotational speed of a vehicle's wheels. However, it is also conceivable that the measurement sensor 105 may be configured as a sensor for temperature, acceleration, pressure, or the like. Now, in order to output or transmit the measured value of the physical parameter detected by the measurement sensor 105, the measured value may advantageously be encoded in Manchester code and thus read out by a corresponding analysis and processing device in or on the first energy supply unit 110 and / or the second energy supply unit 115. However, it should be ensured that, even in the event of a failure, when it is necessary to switch to supplying electrical energy from another power supply unit to the measuring sensor 105, the measuring sensor 105 is supplied with the same voltage or the same current as much as possible. For example, if such a change in the power supply source is to be performed in order to read the encoded measurement value from the measuring sensor 105 with the least possible error, such a consistent voltage supply is particularly helpful.

[0031] To ensure a uniform current or voltage supply to the measuring sensor 105, current can be fed to the measuring sensor 105 through the first connection portion 120 of the first energy supply unit 110, and conversely, current can be drawn from the measuring sensor 105 through the second connection portion 125 of the first energy supply unit 110. It should be noted that this current through the second connection portion 125 is, for example, drawn to the first ground potential GND1 through the first resistor R1 and the first switch S1. The first switch S1 can be controlled by the first control unit 130, that is, it can be moved to an open or closed state by manipulation. Simultaneously, the current I1 output from the first connection portion 120 can be provided by the first voltage regulator 135 through the first auxiliary switch SH1, which can, for example, be controlled by the first control unit 130. This voltage regulator is, for example, configured as an LDO regulator (LDO = low drop-out). For this purpose, for example, a first supply voltage UV1 is applied to the first voltage regulator 135, and the first voltage regulator is operated by the first regulator unit 140 such that it provides a first voltage U1. For this purpose, the regulator unit 140 can also be coupled to a first switching element 145, which is connected between the first supply voltage UV1 and a first ground potential GND1. For example, the first switching element 145 can include a Z-diode 147 and a resistor 149 in a series circuit, wherein the potential between the Z-diode 147 and the resistor 149 serves as a control signal 150 for the regulator unit 140. Therefore, by selecting the breakdown voltage of the Z-diode 147, the first voltage U1 can be controlled or determined, for example, in the regulator unit 140.

[0032] Now, a very similar configuration can be chosen for the second energy supply unit 115 so that current or voltage can be supplied to the measuring sensor 105 as uniformly as possible. The second energy supply unit 115 has a third connection 155 through which the second current I2 is fed to the measuring sensor 105. Current can be extracted from the measuring sensor 105 through a fourth connection 160 of the second energy supply unit 115. It should be noted that this current through the fourth connection 160 is, for example, extracted to the second ground potential GND2 through the second resistor R2 and the second switch S2. The second switch S2 can be controlled by the second control unit 165, that is, by manipulation, to be brought to an open or closed state. Meanwhile, the current I2 output at the third connection 155 can be provided by the second voltage regulator 170 through the second auxiliary switch SH2, which can, for example, be controlled by the second control unit 165, and the second voltage regulator is also configured as an LDO regulator. For this purpose, for example, a second supply voltage UV2 is applied to the second voltage regulator 170, and the second voltage regulator is operated by the second regulator unit 175 such that it provides the second voltage U2. For this purpose, the second regulator unit 175 can also be coupled to a second switching element 180, which connects the supply voltage UV2 on the control input AD to the fourth connection 160, which is now (e.g., via the measuring sensor 105) coupled to the first ground potential GND1. Specifically, this coupling occurs through the first ground potential GND1, the voltage drop +U_S1 on the first switch S1, and the voltage drop U_R1 on the first resistor R1; therefore, it is indirect coupling. For example, the switching element 180 can have a second Z-diode 185 and an additional resistor 190 in series, wherein the potential between the second Z-diode 180 and the additional resistor 190 serves as the control signal 192 for the second regulator unit 175. Therefore, the output of the second voltage U2 can be controlled or determined, for example, in the second regulator unit 175, by means of the breakdown voltage of the second Z-diode 180.

[0033] Then, in such a supply circuit of the measuring sensor 105, the first connection portion 120 of the first energy supply unit 110 is connected to the third connection portion 155 of the second energy supply unit 115, and the second connection portion 125 of the first energy supply unit 110 is connected to the fourth connection portion 160 of the second energy supply unit 115.

[0034] Instead of coupling the first energy supply unit 110 to the second ground potential in the same type of construction as the second energy supply unit 115, coupling the control input AD (AD = Adjust-Steuerpin, adjustment control pin = Steuerpin zum Einlesen eines Steuersignals, control pin for reading control signals) of the second energy supply unit 115 to the first ground potential GND1, it is now possible to achieve a correspondingly advantageous determination of the second voltage U2, which helps to avoid voltage jumps when replacing the energy supply of the measuring sensor 105 in the event of a fault and thus ensures the robust operation of the measuring sensor 105.

[0035] Now, according to one embodiment of the proposed solution, the control input terminal AD of the second energy supply unit 115, more precisely the second regulator unit 175, is connected to the first ground potential GND1. This is achieved here through an electrical connection line from the control input terminal AD to the fourth connection portion 160 of the second energy supply unit 115, which itself is coupled to the first ground potential via the measuring sensor 105, the first resistor R1, and the first switch S1. This achieves the following: when adjusting the second voltage U2 from the second supply voltage UV2, the first ground potential GND1 is used as the reference parameter instead of the second ground potential GND2. In this way, the adjustment of the second voltage U2, which is output to the measuring sensor 105 between the third connection portion 155 and the fourth connection portion 160, is achieved. In this case, the voltage U1 output from the first energy supply unit 110 to the measuring sensor 105 and the potential difference between the first and second ground potentials are considered and compensated. This also ensures that... Figure 1 In the wiring configuration shown, fault current does not flow from the first energy supply unit 110 to the second energy supply unit 115 due to voltage differences between the first connection 120 and the second connection 135, and between the third connection 155 and the fourth connection 160. Furthermore, this helps to maintain the required supply range of the sensor and prevents overvoltage supply. This can lead to favorable availability estimates. For this purpose, it should be noted that the sensor must meet an extended temperature range, which the sensor manufacturer guarantees when the maximum supply voltage is reduced (i.e., self-heating is limited).

[0036] Furthermore, a shunt resistor RS is provided between the second auxiliary switch SH2 and the third connection 155, which is used, for example, to measure the current I2 flowing through the third connection 155 to the measuring sensor 105. Especially when the measuring sensor 105 outputs a measured value of the physical parameter to be measured by changing the current flowing through the measuring sensor 105, using such a shunt resistor for such measurement or analysis of the value encoded by the measuring sensor 105 can be very advantageous. However, it is also conceivable that the current flowing through the measuring sensor 105, or the current changed by the measuring sensor 105, can be detected by the voltage drop across the first resistor R1 and / or the second resistor R2.

[0037] Now, in order to ensure robust and reliable measurement by measuring sensor 105, the first control unit 130 and the second control unit 165 can be configured to switch the first switch S1, the first auxiliary switch SH1, the second switch S2 and the second auxiliary switch SH2 such that, for example in normal operating mode, i.e. during normal operation, the second energy supply unit 115 supplies energy or current I2 to the measuring sensor 105 through the third connection 155, and the current flowing out of the measuring sensor 105 is conducted through the second connection 125 of the first energy supply unit 110 through the first resistor R1 and the first switch S1.

[0038] However, if a fault occurs now in the first energy supply unit 110 or the second energy supply unit 115, the fault is, for example, caused by... Figure 1 The fault identification unit (not shown) transmits the information to the first control unit 130 and / or the second control unit 165, and the relevant control unit 130 or 165 can switch the switches S1, SH1, S2 and SH2 controlled by it in such a way that no current flows through the faulty energy supply unit.

[0039] In particular, for example, when a fault occurs in the first energy supply unit 110, the relevant switches can be switched in an operational manner by the control unit, so that the first switch S1 and / or the first auxiliary switch SH1 are opened, and therefore no current can flow through the first connection 120 and / or the second connection 125. Alternatively or additionally, the second control unit 165 can be operated in such a way that the second switch S2 and the second auxiliary switch SH2 are closed, so that current can flow through the third connection 155 and the fourth connection 160, and therefore the power supply to the measuring sensor 105 is achieved only through the second energy supply unit 115.

[0040] Conversely, for example, when a fault occurs in the second energy supply unit 115, the first control unit can be switched such that the first switch S1 and the first auxiliary switch SH1 are closed, so that current can flow through the first connection 120 and the second connection 125.

[0041] Alternatively or additionally, the second control unit 165 may be manipulated such that the second switch S2 and / or the second auxiliary switch SH2 are turned on, preventing current from flowing through the third connection 155 and the fourth connection 160, so that power is supplied to the measuring sensor 105 only through the first power supply unit 115.

[0042] Figure 2 A flowchart illustrating an embodiment of the proposed scheme as a variation of method 200 for operating the measurement system described herein is shown. Method 200 includes a step 210 of supplying electrical energy to a measurement sensor from a first energy supply unit and / or a second energy supply unit, and a step 220 of outputting a measurement signal representing a physical parameter through the measurement sensor.

[0043] In summary, this paper proposes a possibility for the principle and circuitry of generating a variable reference potential for a voltage source that supplies a diagonal voltage to sensors used in two control devices, under the current circumstances.

[0044] As an extension, the basic principle of diagonal supply and analysis of a sensor (Example aWSS) via two electronic control devices or power supply units can be explained. This principle is based on the following problem: the primary and redundant ECUs (here referred to as the first and second power supply units 110 or 115) are typically fed by different voltage supply devices and therefore have different grounding references due to the cables used. Even when supplied by a common voltage supply device, it should be assumed that there is a continuous, varying grounding misalignment between the primary ECU or power supply unit 110 and the redundant ECU or power supply unit 115. This grounding misalignment, or interference caused by different grounding potentials, makes it difficult to analyze and guarantee the permissible voltage range of the sensor signal output by the measuring sensor 105. A voltage drop in the voltage supply device of the sensor or measuring sensor 105 can further damage the sensor signal. This then results in an erroneous analysis record of the sensor 105. The proposed solutions here include exemplary circuit suggestions that specifically address the issue of grounding misalignment in the case of diagonal supply and analysis processing of the drive wheel speed sensor, which is used as measurement sensor 105.

[0045] Figure 1The schematic diagram shows the electrical wiring of the primary control device 110 and the redundant control device 115, or the corresponding energy supply unit 110 or 115, for diagonal supply and analysis processing of the active wheel speed sensor (aWSS) as the measurement sensor 105, and shows the normal operation of the two ECUs or energy supply units 110 and 115. A current flow is present, starting from the redundant ECU or the second energy supply unit 115 with a supply voltage level UV1, passing through the LDO or the second regulator unit 170, through the measurement sensor 105 via a reverse current-protected supply switch on the high side (which also has a current mirror, for example), to a shunt on the low side as a first resistor R1. This reverse current-protected supply switch acts as a second auxiliary switch SH2 with a shunt RS. The measurement sensor here is configured as an active speed sensor. The basic idea of ​​the proposed solution is described herein, including the principle and a specific embodiment comprising circuit suggestions. Specifically, the reference potential for the source voltage regulation refers to the reference potential of the primary ECU (here, the branch between the first connection 135 and the first ground potential GND1), and the voltage regulation device exists here as the first regulator unit 135. Under normal circumstances, it can be known from this normal situation that... Figure 1 The connection structure shown in the diagram indicates that the reference potential is the grounding of its own control equipment, such as... Figure 1 As shown. This ground reference, relative to the primary control device 110, improves the robustness of sensor recordings against ground misalignment. This primary control device is used to regulate the LDO, which serves as a redundant control device or the regulator unit 135 of the second energy supply unit 115. Here, the anode of the diode 185 or 147, used as a switching element, is no longer selected to have an internal ground, but rather to have a reference relative to the signal applied to the fourth connection 160. This reference potential substantially corresponds to the same potential of the primary ECU or the first energy supply unit 110. It is important to ensure safe operation even in the event of a failure of the control devices 130 or 165 when selecting the ground reference GND2. The redundant ECU 115 does not change its voltage direction relative to the ground reference of the primary ECU 110. Safe operation is also ensured in the event of a failure of the primary ECU or the first energy supply unit 110. The module or energy supply unit 110 or 115 has been briefly described above. In additional expansion stages, a filter element may be implemented between the fourth connection 160 and the diode serving as the second switching element 185. Here, the dynamic characteristics of LDO regulation can be limited.

[0046] If an embodiment includes an "and / or" connection between a first feature and a second feature, it can be interpreted as follows: the embodiment, according to one implementation, has both the first feature and the second feature, and according to another implementation, has either only the first feature or only the second feature.

[0047] List of reference numerals

[0048] 100 Measurement System

[0049] 105 Measurement Sensor

[0050] 110 First Energy Supply Unit

[0051] 115 Second Energy Supply Unit

[0052] 120 First connecting part

[0053] 125 Second connecting part

[0054] 130 First Control Unit

[0055] 135 Regulator Unit

[0056] 140 Voltage Regulator

[0057] 145 Switching element

[0058] 147 First Z-Diode

[0059] 149 resistor

[0060] 150 tap points

[0061] UV1 First Supply Voltage

[0062] U1 First Voltage

[0063] S1 First Switch

[0064] R1 is the first resistor.

[0065] SH1 First Auxiliary Switch

[0066] I1 First Current

[0067] GND1 First grounding potential

[0068] 155 Third Connecting Part

[0069] 160 Fourth connecting part

[0070] 165 Second Control Equipment

[0071] 170 Second Regulator Unit

[0072] 175 Second Voltage Regulator

[0073] 180 Second switching element

[0074] AD control input terminal

[0075] 185 Second Z-Diode

[0076] 190 resistor

[0077] U2 Second Voltage

[0078] UZV Second Supply Voltage

[0079] I2 Second Current

[0080] SH2 Second Auxiliary Switch

[0081] R2 is the second resistor.

[0082] RS shunt resistor

[0083] GND2 Second Grounding Potential

[0084] 200 Method for operating a measurement system according to a variant presented herein

[0085] 210 Supply Steps

[0086] 220 Output Steps

Claims

1. A measurement system (100) for detecting physical parameters, wherein, The measurement system (100) has the following characteristics: - A measurement sensor (105) for detecting the physical parameters; - A first energy supply unit (110) for outputting current or electrical energy to the measuring sensor (105), wherein the first energy supply unit (110) is configured to output the electrical energy to the measuring sensor (105) at a first voltage (U1) relative to a first ground potential (GND1); - A second energy supply unit (115) for outputting current (I2) or electrical energy to the measuring sensor (105), wherein the second energy supply unit (115) is configured to output the electrical energy to the measuring sensor (105) at a second voltage (U2) relative to a second ground potential (GND2), wherein the first ground potential (GND1) is different from the second ground potential (GND2); The first energy supply unit (110) and the second energy supply unit (115) are based on different ground potentials (GND1, GND2). The second energy supply unit (115) has a control input (AD) for adjusting the second voltage (U2), wherein the control input (AD) is coupled to the first ground potential (GND1) so as to manipulate the second energy supply unit (115) such that the voltage output from the second energy supply unit (115) to the measuring sensor (105) corresponds to a first voltage (U1) relative to the first ground potential (GND1). The second energy supply unit (115) has switching elements (180, 185) connected to the control input terminal (AD). These switching elements are configured to control the second voltage (U2) based on the following voltage difference: the supply voltage (U) that powers the second energy supply unit (115). V2 The voltage difference between the ground potential (GND1) and the first ground potential (GND1).

2. The measurement system (100) according to claim 1, characterized in that, The first energy supply unit (110) has at least one first switch (S1) controllable by a first control unit (130) to interrupt the current from the measuring sensor (105) through the first energy supply unit (110) to the first ground potential (GND1), and / or, the second energy supply unit (115) has at least one second switch (S2) controllable by a second control unit (165) to interrupt the current from the measuring sensor (105) through the second energy supply unit (115) to the second ground potential (GND2).

3. The measurement system (100) according to claim 2, characterized in that, The first control unit (130) is configured to turn on the first switch (S1) when a malfunction of the first energy supply unit (110) is detected, and / or the second control unit (165) is configured to turn on the second switch (S2) when a malfunction of the second energy supply unit (115) is detected.

4. The measurement system (100) according to claim 2 or 3, characterized in that, The first control unit (130) is configured to close the first switch (S1) or keep the first switch (S1) closed when a functional failure is detected in the second unit (115), and / or, wherein the second control unit (165) is configured to close the second switch (S2) or keep the second switch (S2) closed when a functional failure is detected in the first energy supply unit (110).

5. The measurement system (100) according to any one of claims 1-3, characterized in that, The measuring sensor (105) is connected in the supply circuit to the first energy supply unit (110) and the second energy supply unit (115) such that the second energy supply unit (115) provides current (I2) to the measuring sensor, and the current is led out from the measuring sensor to the first energy supply unit (110), wherein the measuring sensor (105) is turned on in the supply circuit during normal operation.

6. The measurement system (100) according to any one of claims 1-3, characterized in that, The second energy supply unit (115) has a shunt resistor (RS) through which the current (I2) flows from the second energy supply unit (115) to the measurement sensor (105) during normal operation.

7. The measurement system (100) according to any one of claims 1-3, characterized in that, The measurement sensor (105) is configured to encode the values ​​representing the physical parameters into Manchester codes.

8. The measurement system (100) according to any one of claims 1-3, characterized in that, The first energy supply unit (110) and / or the second energy supply unit (115) have at least one voltage regulator (135, 140, 170, 175) implemented as a low-dropout longitudinal regulator.

9. The measurement system (100) according to any one of claims 1-3, characterized in that, The measuring sensor (105) is configured as a rotational speed sensor to detect the rotational speed of vehicle components and / or the rotational speed of the vehicle wheels.

10. A method (200) for operating a measurement system (100) according to any one of claims 1 to 9, wherein, The method (200) includes the following steps: - Supply (210) electrical energy from the first energy supply unit and / or the second energy supply unit (115) to the measurement sensor (105); - A measurement signal (220) is output by the measurement sensor (105), the measurement signal representing the physical parameter.

11. A computer program configured to perform and / or manipulate the steps of the method (200) according to claim 10.

12. A machine-readable storage medium on which a computer program according to claim 11 is stored.

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