Measuring arrangement for a vehicle electrical system of a motor vehicle, vehicle electrical system, motor vehicle

Abstract

A measuring arrangement (70) for a vehicle electrical system (61) of a motor vehicle (50), the measuring arrangement comprising: a supply line (71) for supplying electrical energy to the vehicle electrical system and / or to a component (65) of the vehicle electrical system; a part (72) in the form of an inductor (72a) or a capacitor (72b); an ohmic measuring resistor (73) connected in series with the part; a comparator (74), the comparator being designed to compare a measurement voltage (UM) applied to the measuring resistor with a reference voltage (UR) and then to output a comparison signal (80); and a data processing device (51), the data processing device being designed to adjust a sampling rate (FS) on the basis of the comparison signal; wherein the part is connected to the supply line in such a way that a change over time in an electrical variable (U, I) characterizing the electrical energy brings about a change in the measurement voltage.

Description

[0001] Measuring arrangement for a vehicle electrical system, vehicle electrical system, motor vehicle

[0002] The present disclosure relates to a measuring arrangement for an on-board electrical system of a motor vehicle. The disclosure relates equally to an on-board electrical system for a motor vehicle and to a motor vehicle.

[0003] It is known from the prior art to equip motor vehicles with analog measuring technology in order to monitor a vehicle's electrical system, a component of the electrical system and / or parts of the component. This can include recording voltages at various locations or measuring points in the on-board power system, the power consumption of one or more of the components, for example, and the temperature of electrical supply lines. Particularly with regard to recording current and voltage, comparatively high sampling rates may be required in order to correctly record dynamic processes and / or transients. However, dynamic processes relevant for the design of the on-board power system do not occur continuously when the vehicle is in operation, for example during an entire journey, but rather during short-term peak load scenarios and / or load changes.

[0004] WO 2023 / 174631 A1 discloses an electrified motor vehicle with a high-voltage storage device, at least one electric motor, power electronics, a DC / DC converter, and an electronic evaluation unit for central, component-specific energy monitoring of defined components of a low-voltage vehicle electrical system and / or defined components of a high-voltage vehicle electrical system. The evaluation unit is designed such that a specific load signature is stored therein for each defined component, and that an overall measurement signal acquired outside the defined components with a first (single) measuring sensor for the entire low-voltage vehicle electrical system and / or with a second (single) measuring sensor for the entire high-voltage vehicle electrical system is disaggregated to detect the load signatures using NILM technology.Furthermore, the respective total measurement signal is cleaned of vehicle-specific electrical disturbances by a defined correction module before disaggregation.

[0005] Conventionally, measurements are initiated or triggered based on threshold values, for example in oscilloscopes. If a threshold value is exceeded, a measurement recording is started accordingly. Triggering based on digital processes, e.g. due to a discrete derivative of a measurement signal and / or a special algorithm, is also known. However, the sampling rate selected due to the dynamic processes leads to measurements being taken at the comparatively high sampling rate even for less dynamic processes and / or in stationary or quasi-stationary states. Overall, this results in a rather unnecessarily large amount of data, since the comparatively high sampling rate is too high for less dynamic processes and / or measurements at the comparatively high sampling rate lead to little useful information for less dynamic processes.Therefore, to reduce the amount of data, it is useful to dynamically adjust the sampling rate.

[0006] However, a digital implementation of the dynamic adjustment of the sampling rate does not necessarily seem to be effective. Due to the computing time of digital implementations, a digital implementation of the dynamic adjustment has a comparatively high response time or inertia, which can, for example, complicate and / or delay the detection of steep edges in the measurement signal, which can also delay a dynamic increase in the sampling rate. Furthermore, the digital implementation depends on a selected base sampling rate or a minimum sampling rate. Pure threshold detection neglects highly dynamic component loads in the low power range, whereas loads in the high power range are recorded with high resolution regardless of the dynamics. Furthermore, the threshold-based increase in the sampling rate requires an additional measuring resistor, e.g.a shunt, and / or a resistance measurement on a transistor, for example a MOSFET, which must first be evaluated by the measuring technology.

[0007] Against the background of this prior art, one object of the present disclosure is to provide a device suitable for enriching the prior art and improving at least the above-mentioned aspects of the prior art. In particular, the object of the disclosure is to enable efficient dynamic adaptation of a sampling rate of a measurement in a motor vehicle.

[0008] The problem is solved by the features of the independent claims. The subclaims contain further developments of the disclosure.

[0009] According to one aspect of the disclosure, the object is achieved by a measuring arrangement for an on-board electrical system of a motor vehicle, the measuring arrangement comprising: a supply line for supplying electrical energy to the on-board electrical system and / or a component of the on-board electrical system; a component designed as an inductor or capacitor; an ohmic measuring resistor connected in series with the component; a comparator, the comparator being configured to compare a measuring voltage applied to the measuring resistor with a reference voltage and then output a comparison signal; and a data processing device, the data processing device being configured to adapt a sampling rate based on the comparison signal; the component being connected to the supply line in such a way that a temporal change in an electrical quantity characterizing the electrical energy causes a change in the measuring voltage.

[0010] It was discovered that the measurement setup allows for dynamic adjustment of the sampling rate based on a trigger. The trigger can be the comparison signal output by the comparator.

[0011] It was discovered that, depending on whether the component is configured as an inductor or a capacitor, it delivers a response reflected in the measurement voltage to a change in the electrical quantity as a current or to a change in the electrical quantity as a voltage. A comparatively rapid change in the electrical quantity can be translated into a comparatively large measurement voltage, while a comparatively slow change in the electrical quantity can be translated into a comparatively low measurement voltage. Therefore, the comparator can determine a comparatively high or low dynamic response by comparing the measurement voltage with the reference voltage. The sampling rate can therefore be selected to be proportional to the measurement voltage, for example, in order to achieve a higher sampling rate with a higher measurement voltage, which indicates fast dynamic response, than with a lower measurement voltage, which indicates slower dynamic response.This eliminates the need to define a base sampling rate. This makes the measuring device reliable and thus more efficient. The disclosure enables dynamic adjustment of the sampling rate, particularly based on transient processes in the measured variables. The implementation is analog. This enables rapid changes or adjustments to the sampling rate.

[0012] Furthermore, it was recognized that motor vehicles, including prototypes, pre-production vehicles, and production vehicles, can be equipped relatively easily with such a measurement setup. One example application could be an electronic fuse (so-called "E-fuse") that can capture measurement data at an adjustable sampling rate. This enables the acquisition of dynamic measurement data from the vehicle electrical system.

[0013] Dynamic adaptation allows the sampling rate to be increased for more dynamic signals and decreased for less dynamic signals. This allows for an improved design of the on-board network and / or components despite a significantly reduced data volume, and / or enables more reliable and comprehensive monitoring during vehicle operation. This is particularly relevant in customer operations or in production vehicles, as data loggers typically cannot be installed to store large amounts of data, and transmitting measurement data, for example, via a mobile network, is comparatively costly.

[0014] Optionally, the component and the supply line each have an impedance, and the component's impedance is small compared to the supply line's impedance. In other words, the component's impedance should be significantly smaller than the supply line's impedance in the frequency range under consideration to reduce interference with the system being measured.

[0015] Optionally, the component is designed as an inductor; the component is connected in series with a component of the vehicle electrical system. It was discovered that a temporal change in the current in the component, and thus in the inductance, can be proportional to a change in the voltage in the inductor and thus proportional to the measured voltage. The measured voltage can therefore provide direct information about the change in the current and thus the dynamics, and justify an adjustment of the sampling rate.

[0016] Optionally, the component is designed as a capacitor; and the component is connected in parallel with a component of the vehicle electrical system. It was discovered that a temporal change in the voltage in the component can be proportional to a change in the current in the capacitor and thus proportional to the measured voltage. The measured voltage can therefore provide direct information about the change in the voltage and thus the dynamics, and justify an adjustment of the sampling rate.

[0017] Optionally, the component is connected to the supply line in such a way that a temporal change in an electrical quantity characterizing the electrical energy causes a proportional change in the measuring voltage. It was recognized that this allows the component's fundamental property of translating a change in the electrical quantity into a voltage across the measuring resistor to be exploited particularly effectively and interpretably.

[0018] According to one aspect of the disclosure, an on-board electrical system for a motor vehicle is provided, comprising at least one measuring arrangement as described above. Optionally, the measuring arrangement has one or more features described as advantageous or optional in order to achieve an associated technical effect. It has also been recognized that the on-board electrical system can have several optionally different measuring arrangements, for example, a measuring arrangement with a component designed as an inductance for monitoring the on-board electrical system and a measuring arrangement with a component designed as a capacitor for monitoring a component.

[0019] Optionally, the vehicle electrical system can be configured as a low-voltage system. It was recognized that the low-voltage system can be monitored particularly effectively, especially if the low-voltage system includes electronic fuses for monitoring the low-voltage system, and the sampling rate of the electronic fuses is influenced by the measuring setup.

[0020] Optionally, the supply line is configured to supply electrical energy to the vehicle electrical system; and the component is designed as an inductor. This allows adaptive monitoring of the vehicle electrical system. The supply line is configured as an on-board electrical system input.

[0021] Optionally, the vehicle electrical system includes a component; the supply line is configured to supply electrical energy to the component; and the component is designed as a capacitor. This allows the component to be adaptively monitored. The supply line is configured as a component input.

[0022] According to one aspect of the disclosure, a motor vehicle comprising the above-described electrical system is provided. Optionally, the electrical system and / or its measuring arrangement has one or more features described as advantageous or optional in order to achieve an associated technical effect.

[0023] In the following, one embodiment is described with reference to the figures.

[0024] Fig. 1 schematically shows a motor vehicle according to one aspect of the disclosure; Fig. 2 schematically shows components of an on-board network and a measuring arrangement, each according to one aspect of the disclosure; and

[0025] Fig. 3 schematically shows components of a component of an on-board network and of a measuring arrangement, each according to an aspect of the disclosure.

[0026] Figure 1 schematically shows a motor vehicle 50 according to one aspect of the disclosure.

[0027] Motor vehicle 50 is a land vehicle. Motor vehicle 50 is a passenger car.

[0028] The motor vehicle 50 has an on-board electrical system 61 embodied as a low-voltage network 60. The low-voltage network 60 or low-voltage system is configured, for example, to operate with alternating voltages up to and including 30 V or direct voltages up to and including 60 V. The low-voltage network 60 comprises an electronic measuring device embodied as an electronic fuse 52a ("E-fuse") and a component 65. In another embodiment (not shown), the motor vehicle 50 may have a number of electronic measuring devices and / or components 65 other than that shown.

[0029] Component 65 may, for example, include or be a sensor, an actuator, and / or a control unit. Component 65 is configured to be supplied with electrical energy or, when a voltage is applied, with a current. Component 65 has a plurality of components 66, the number of which is only schematic. Components 66 are electrically interconnected and can therefore influence one another and determine the function of component 65.

[0030] The electronic fuse 52a is configured to electrically protect the component 65, i.e. to protect it against excessively high currents and / or voltages. The electronic fuse 52a is configured to measure, as measured variables, a time-dependent input current signal relating to the component 65, a time-dependent input voltage signal and optionally a time-dependent temperature signal. The input current signal represents, for example, the current I applied to the component 65 as a function of time, and the input voltage signal represents the voltage U applied to the component 65 as a function of time. The temperature signal represents the temperature of the component as a function of time. The temperature signal can refer to one or more measuring points. The electronic fuse 52a is configured to measure the measured variables at a sampling rate FS.The sampling rate FS indicates the number of measurements per period, for example, in measurements per second. The electronic fuse 52a comprises and / or is communicatively connected to a data processing device 51 (not shown), wherein the data processing device 51 is configured to monitor the measurement by the electronic fuse 52a and, in particular, to change or adapt the sampling rate FS.

[0031] The motor vehicle 50 or the on-board electrical system has a measuring arrangement 70, which is only partially shown in Figure 1. Embodiments of the measuring arrangement 70 are each described in detail with reference to Figures 2 and 3.

[0032] Figure 2 schematically shows components of an on-board electrical system 61 and a measuring arrangement 70, each according to an aspect of the disclosure. Such an on-board electrical system 61 of a motor vehicle 50 is described with reference to Figure 1. Figure 2 is described with reference to Figure 1.

[0033] The measuring arrangement 70 according to Figure 2 has a supply line 71 for supplying electrical energy to the vehicle electrical system 61. The supply line 71 is thus configured to supply electrical energy to the vehicle electrical system 61. The vehicle electrical system 61 can comprise one or more components 65 (see Figure 1) that are not shown in Figure 2. The supply line 71 has an impedance Z and an inductance L, as schematically illustrated by the impedance Z and the inductance L in the dashed-line box indicated by the reference symbol of the supply line 71.

[0034] The vehicle electrical system 61 can be supplied with electrical energy, in particular by applying an electrical current I as an electrical quantity. Figure 2 also shows a voltage measuring device 67 configured to measure a voltage U as an electrical quantity.

[0035] The measuring arrangement 70 has a component 72 embodied as an inductor 72a. The inductor 72a comprises, for example, a coil and / or choke. The inductor 72a has an impedance Z and an inductance L, as schematically illustrated by the impedance Z and the inductance L in the dashed-line box indicated by the reference symbol of the inductor 72a. The measuring arrangement 70 also has an ohmic measuring resistor 73 connected in series with the component 72. A voltage difference across the inductor 72a is therefore calculated as UM = R_MI x I + L_MI x dl / dt, where UM is the measuring voltage, R_MI is the ohmic resistance of the measuring resistor 73, I is the current, and dl / dt is the time derivative of the current I. The impedance Z of the component 72 is small compared to the impedance Z of the supply line 71. The inductance L of the component 72 is small compared to the inductance L of the supply line 71.Neglecting the ohmic resistance of the component 72, the measured voltage UM is proportional to the temporal change or derivative of the current I. The component 72 is connected in series to a component 65 (not shown in Figure 2) of the vehicle electrical system 61. The component 72 is thus connected to the supply line 71 in such a way that a temporal change in an electrical quantity U , I characterizing the electrical energy causes a change in the measured voltage UM. The component 72 is connected to the supply line 71 in such a way that a temporal change in an electrical quantity U , I characterizing the electrical energy causes a proportional change in the measured voltage UM.

[0036] The measuring arrangement 70 has a comparator 74. In one embodiment, the comparator 74 can be designed as and / or comprised of an analog-to-digital converter. The comparator 74 is configured to compare a measurement voltage UM applied to the measuring resistor 73 with a reference voltage UR and then output a comparison signal 80. The comparison signal 80 can be binary: The comparator 74 is then configured to output the comparison signal 80 with a first value when the measurement voltage UM is greater than the reference voltage UR, and to output the comparison signal 80 with a second value different from the first value when the measurement voltage UM is less than the reference voltage UR.

[0037] The data processing device 51 (see Figure 1) is configured to receive the comparison signal 80 and to adapt the sampling rate FS based on the comparison signal 80.

[0038] The measuring arrangement 70 according to Figure 2 thus enables, for example, the detection of edges and / or gradients by measuring the voltage at a known inductance 72a in the supply line 71 of component 65. This can be, for example, the inductance present in the input circuit of component 65 or a small, additional measuring inductance. The voltage U at the measuring inductance 72a, which is proportional to the change in current I over time, is recorded and amplified quickly and cost-effectively by an optional measuring amplifier (not shown). This optionally amplified measuring voltage UM is compared with the reference voltage UR via the comparator 74. If the reference voltage UR is exceeded, the sampling rate FS is dynamically increased. This enables rapid detection of edges and a corresponding increase in the sampling rate FS.By comparing with the reference voltage UR, it is possible to set a specific current change as a trigger for the high-frequency sampling of a measured variable.

[0039] Figure 3 schematically shows components of a component 65 of an on-board electrical system 61 and a measuring arrangement 70, each according to an aspect of the disclosure. Such an on-board electrical system 61 and such a component 65 of a motor vehicle 50 are described with reference to Figure 1. Figure 3 is described with reference to Figure 1. Furthermore, Figure 3 is described with reference to Figure 2, wherein the differences between Figures 2 and 3 are described.

[0040] The measuring arrangement 70 according to Figure 3 has a supply line 71 for supplying electrical energy to component 65 of the vehicle electrical system 61. The supply line 71 is thus configured to supply electrical energy to component 65 of the vehicle electrical system 61. The component 65 can comprise one or more components 66 (see Figure 1) that are not shown in Figure 3. The supply line 71 has an impedance Z and an inductance L, as schematically illustrated by the impedance Z and the inductance L in the dashed-line box indicated by the reference symbol of the supply line 71.

[0041] The component 65 can be supplied with electrical energy, in particular by applying an electrical current I as an electrical quantity. Figure 3 also shows a voltage measuring device 67 configured to measure a voltage U as an electrical quantity.

[0042] The measuring arrangement 70 comprises a component 72 embodied as a capacitor 72b. The capacitor 72b has an impedance Z and a capacitance C, as schematically illustrated by the impedance Z and the capacitance C in the dashed-line box indexed by the reference symbol of the capacitor 72b.

[0043] The measuring arrangement 70 also has an ohmic measuring resistor 73 connected in series with the component 72. A current difference across the component 72 is calculated using l_MK = C * dU / dt, so that the current of the capacitor 72b is directly proportional to the temporal change dU / dt of the voltage U of the vehicle electrical system 61. The impedance Z of the component 72 is small compared to the impedance Z of the supply line 71. The component 72 is connected in parallel to a component 66 (not shown in Figure 3) of the component 65. The current l_MK in the capacitor 72b causes a current through the measuring resistor 73 and thus the measuring voltage UM. The component 72 is thus connected to the supply line 71 in such a way that a temporal change in an electrical quantity U , I characterizing the electrical energy causes a change in the measuring voltage UM.The component 72 is connected to the supply line 71 in such a way that a temporal change in an electrical quantity U, I characterizing the electrical energy causes a proportional change in the measuring voltage UM.

[0044] The comparator 74 is the comparator 74 described with reference to Figure 2.

[0045] The detection of edges and / or gradients takes place according to the measuring arrangement 70 in Figure 3 by a current measurement at a capacitor 72b with a known capacitance C in the supply line 71 of the component 65 and / or a part 66 of the component. This can be, for example, an input capacitance present in the input circuitry or an additionally installed measuring capacitance. The current I through the capacitor 72b, which is proportional to the change in the measuring voltage U, is recorded and converted into the measuring voltage UM by a downstream measuring resistor 73. This measuring voltage UM is amplified quickly and cost-efficiently by an optional measuring amplifier (not shown). This optionally amplified measuring voltage UM is compared with the reference voltage UR via the comparator 74. If the reference voltage UR is exceeded, the sampling rate FS is dynamically increased.This enables rapid detection of edges and a corresponding increase in the sampling rate FS. Comparison with the reference voltage UR allows setting a specific voltage change as a trigger for the high-frequency sampling of a measured value.

[0046] Reference symbol (part of the description)

[0047] 50 motor vehicles

[0048] 51 Data processing device

[0049] 52a electronic fuse

[0050] 60 low-voltage network

[0051] 61 On-board network

[0052] 65 components

[0053] 66 component

[0054] 67 Voltage measuring device

[0055] 70 measuring arrangement

[0056] 71 supply line

[0057] 72 components

[0058] 72a Inductance

[0059] 72b capacitor

[0060] 73 Measuring resistor

[0061] 74 Comparator

[0062] 80 comparison signal

[0063] C capacity

[0064] FS sampling rate

[0065] I electrical quantity, current

[0066] L Inductance

[0067] U electrical quantity, voltage

[0068] UM measuring voltage

[0069] UR reference voltage

[0070] Z Impedance

Claims

Claims 1. Measuring arrangement (70) for an on-board network (61) of a motor vehicle (50), wherein - the measuring arrangement (70) comprises: - a supply line (71) for supplying electrical energy to the vehicle electrical system (61) and / or a component (65) of the vehicle electrical system (61); - a component (72) designed as an inductor (72a) or capacitor (72b); - an ohmic measuring resistor (73) connected in series with the component (72); - a comparator (74), wherein the comparator (74) is configured to compare a measuring voltage (UM) applied to the measuring resistor (73) with a reference voltage (UR) and then output a comparison signal (80); and - a data processing device (51), wherein the data processing device (51) is configured to adapt a sampling rate (FS) based on the comparison signal (80); wherein - the component (72) is connected to the supply line (71) in such a way that a temporal change in an electrical quantity (U , I) characterising the electrical energy causes a change in the measuring voltage (UM).

2. Measuring arrangement (70) according to claim 1, wherein the component (72) and the supply line (71) each have an impedance (Z), and the impedance (Z) of the component (72) is small compared to the impedance (Z) of the supply line (71).

3. Measuring arrangement (70) according to claim 1 or 2, wherein - the component (72) is designed as an inductance (72a); and - the component (72) is connected in series to a component (65) of the vehicle electrical system (61).

4. Measuring arrangement (70) according to claim 1 or 2, wherein - the component (72) is designed as a capacitor (72b); and - the component (72) is connected in parallel to a component (66) of a component (65) of the vehicle electrical system (61).

5. Measuring arrangement (70) according to one of the preceding claims, wherein the component (72) is connected to the supply line (71) in such a way that a temporal change in an electrical quantity (U,l) characterizing the electrical energy causes a proportional change in the measuring voltage (UM).

6. On-board electrical system (61) for a motor vehicle (50), comprising at least one measuring arrangement (70) according to one of the preceding claims.

7. On-board electrical system (61) according to claim 6, wherein the on-board electrical system (61) is designed as a low-voltage network (60).

8. On-board network (61) according to claim 6 or 7, wherein - the supply line (71) is designed to supply the on-board network (61) with electrical energy; and - the component (72) is designed as an inductance (72a).

9. On-board network (61) according to one of claims 6 to 8, wherein - the vehicle electrical system (61) has a component (65); - the supply line (71) is designed to supply the component (65) with electrical energy; and - the component (72) is designed as a capacitor (72b).

10. Motor vehicle (50) comprising an on-board network (61) according to one of claims 6 to 9.

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