DE102022114330A1 - Diagnosing measurements on a vehicle power supply path - Google Patents

Abstract

The invention relates to a vehicle (F) with an on-board power supply system (1) which has at least one power supply path (SVP) to at least one electrical component (7, 11), the vehicle being set up to have a current limiting function (D) for the at least one Power supply path to selectively activate or deactivate values of a first electrical voltage (Ue-fuse) and a first electrical current (Ie-fuse) at a first end (12) of the power supply path, each with activated (Don) and not activated (Doff) current limiting function to determine, to determine values of a second electrical voltage (Uload) and a second electrical current (Iload) at a second end of the power supply path, each with the current limiting function activated and deactivated, to determine at least some of the values with the current limiting function activated and not activated as part of a test procedure , to check whether at least one specified relation applies to the values determined as part of the test process (Ue-fuse, Ie-fuse, Uload, Iload) and/or values derived therefrom (ΔU), and to trigger at least one action if the result the check for at least one relation indicates at least one incorrect determination of a voltage and/or a current and/or incorrect activation of the current limiting function.

Description

The invention relates to a vehicle with an on-board power supply system that has at least one power supply path to at least one electrical component, the vehicle being set up to selectively activate or deactivate a current limiting function for the at least one power supply path, values of a first electrical voltage and a first electrical To determine current at a first end of the power supply path with the current limiting function activated and not activated and to determine values of a second electrical voltage and a second electrical current at a second end of the power supply path with the current limiting function activated and deactivated. The invention also relates to a method in which values of a first voltage and a first current are determined at a first end of the power supply path with the current limiting function deactivated and values of a second voltage at a second end of the power supply path are determined with the current limiting function deactivated. The invention is particularly advantageously applicable to partially or fully autonomous vehicles, in particular fully electric vehicles.

Consumer paths in vehicle energy systems are increasingly being protected by semiconductor-based electronic fuses (also known as “E-Fuses” or “Smart Fuses”). In order to achieve desired FIT (Failure In Time) rates of the load paths, a combination of electronic fuse and current limiting function can be used. In the event of a critical voltage drop accompanied by faulty current limitation, the electronic fuse is blown and the consumer path is disconnected.

Current limiting (also known as “degradation”) is a software function that can be voltage dependent or commanded (“commanded”). In the voltage-dependent variant, values for current and/or voltage are measured at the consumer and, if necessary, a current limitation is initiated by the consumer, e.g. by a higher-level authority. Alternatively or additionally, values for current and/or voltage are measured elsewhere in the on-board electrical system, and activation of the current limiting function is commanded from elsewhere. The commanded degradation is often triggered by a minimum performance or diagnosis of another component (e.g. a battery or a conversion element) in the on-board energy system.

One problem is that the current limiting function and the triggering of the electronic fuse rely on valid measurements, functioning software and, if necessary, reliable communication. If even one of these aspects is faulty, it can have critical effects on the on-board electrical system.

DE 10 2019 120 567 A1 discloses an electrical on-board network for a motor vehicle, which includes a power distributor and a plurality of first lines that are designed to connect a corresponding plurality of electrical components to the power distributor. Furthermore, the on-board electrical system comprises a plurality of semiconductor-based first switching elements for the corresponding plurality of first lines, wherein a specific first switching element of a specific first line is designed to interrupt the specific first line. Furthermore, the on-board electrical system includes a second line, which is designed to connect the power distributor to the on-board electrical system, and a limiting unit, which is set up to limit or prevent a second current on the second line. The vehicle electrical system further comprises a control unit that is set up to determine that the specific first switching element does not open, although a first current through the specific first switching element exceeds a first current threshold; and in response thereto, causing the limiting unit to limit or inhibit the second current on the second line.

DE 10 2020 106 210 A1 discloses an energy supply system for a motor vehicle, with at least one energy source, with a supply rail into which electrical energy can be fed by means of the energy source, with at least two power distributors electrically connected to the supply rail and capable of being supplied with energy from the supply rail, and with a control device, by means of which at least one measured value of the energy supply system can be received and by means of which the power distributors can be controlled depending on the at least one measured value, the power distributors being directly electrically connected to the supply rail and each comprising a plurality of parallel-connected power distribution paths, each with at least one fuse element, via which at least one motor vehicle component can be supplied with electrical energy.

It is the object of the present invention to at least partially overcome the disadvantages of the prior art and, in particular, to provide an improved possibility of protecting electrically operated functional components of an on-board power system of a vehicle, in particular against critical voltage drops.

This task is solved according to the features of the independent claims. Preferred embodiments can be found in particular in the dependent claims.

• - eine Strombegrenzungsfunktion für den mindestens einen Stromversorgungspfad wahlweise zu aktivieren oder zu deaktivieren,
• - Werte einer ersten Spannung und eines ersten Stroms an einem ersten Ende des Stromversorgungspfads jeweils bei aktivierter und deaktivierter Strombegrenzungsfunktion zu bestimmen,
• - Werte einer zweiten Spannung und eines zweiten Stroms an einem zweiten Ende des Stromversorgungspfads jeweils bei aktivierter und deaktivierter Strombegrenzungsfunktion zu bestimmen,
• - im Rahmen eines Testablaufs zumindest einige der Werte bei aktivierter und nicht aktivierter Strombegrenzungsfunktion zu bestimmen,
• - zu überprüfen, ob für die im Rahmen des Testablaufs bestimmten Werte und/oder daraus abgeleitete Werte mindestens eine vorgegebene Relation zutrifft, und
• - mindestens eine Aktion (im Folgenden ohne Beschränkung der Allgemeinheit als „fehlerrelevante“ Aktion bezeichnet) auszulösen, falls das Ergebnis der Überprüfung für mindestens eine Relation auf eine nicht ordnungsgemäße Bestimmung, insbesondere Messung, mindestens einer Spannung und/oder mindestens eines Stroms und/oder auf eine nicht ordnungsgemäße Aktivierung der Strombegrenzungsfunktion hindeutet.

The task is solved by a vehicle with an on-board energy network that has at least one power supply path to at least one electrical component, the vehicle being set up to

• - to either activate or deactivate a current limiting function for the at least one power supply path,
• - to determine values of a first voltage and a first current at a first end of the power supply path with the current limiting function activated and deactivated,
• - determine values of a second voltage and a second current at a second end of the power supply path with the current limiting function activated and deactivated,
• - to determine at least some of the values when the current limiting function is activated and not activated as part of a test procedure,
• - to check whether at least one specified relation applies to the values determined during the test process and/or values derived therefrom, and
• - to trigger at least one action (hereinafter referred to as “error-relevant” action without limiting the generality) if the result of the check for at least one relation indicates an incorrect determination, in particular measurement, of at least one voltage and/or at least one current and/or indicates improper activation of the current limiting function.

This vehicle has the advantage that the relation(s) are used to diagnose whether one or more of the measurements or the associated measuring devices and/or the current limiting function are being carried out or are working properly. If this is not the case, at least one action can be triggered to correct this problem, especially before a critical condition occurs. This in turn makes the protection of power supply paths, in particular consumer paths, in the on-board power supply system more reliable, so that the failure rates of the electrical components connected to these power supply paths are significantly reduced and overall system security is increased. Since the correct function is only checked based on a qualitative behavior defined by the relations, a high measurement resolution is advantageously not necessary. In addition, this plausibility check can be implemented easily and inexpensively without additional hardware.

The vehicle may be a land vehicle, watercraft, aircraft or spacecraft. The land vehicle can be a car, a truck, a motorcycle, a bus, etc. The on-board energy network is not limited to a specific type of vehicle drive and can be used, for example, on vehicles with a motor drive, hybrid drive or (full) electric drive (e.g. based on a battery or hydrogen drive).

It is an embodiment that the vehicle is a partially or fully autonomous vehicle. This is particularly advantageous since the reliability and availability of functional components supplied via secured power supply paths is particularly important, particularly safety-relevant, for such vehicles.

The electrical components of the on-board power system can include, for example, at least one energy source (battery, generator, converter, etc.), at least one consumer, at least one power distributor, at least one electronic fuse, etc. For example, the power supply path can connect a power distributor with a consumer.

The test process can, for example, last between milliseconds and several seconds, with in particular measured values before and after activation of the - previously deactivated - current limiting function be measured. It is particularly advantageous if the residual load on the vehicle electrical system is at least approximately constant during the test process.

The checking of the previously determined values and/or values derived therefrom can be carried out by a data processing device in the vehicle.

• - die bei deaktivierter Strombegrenzungsfunktion, mit D_off bezeichnet, am ersten Ende des Stromversorgungspfads bestimmte Spannung U₁ [D_off];
• - die bei aktivierter Strombegrenzungsfunktion, mit D_on bezeichnet, am ersten Ende des Stromversorgungspfads bestimmte Spannung U₁ [D_on];
• - die bei deaktivierter Strombegrenzungsfunktion am zweiten Ende des Stromversorgungspfads bestimmte Spannung U₂ [D_off];
• - die bei aktivierter Strombegrenzungsfunktion am ersten Ende des Stromversorgungspfads bestimmte Spannung U₂ [D_on];
• - die bei deaktivierter Strombegrenzungsfunktion am ersten Ende des Stromversorgungspfads bestimmte Stromstärke I₁ [D_off];
• - die bei aktivierter Strombegrenzungsfunktion am ersten Ende des Stromversorgungspfads bestimmte Stromstärke I₁ [D_on];
• - die bei deaktivierter Strombegrenzungsfunktion am zweiten Ende des Stromversorgungspfads bestimmte Stromstärke I₂ [D_off]; und/oder
• - die bei aktivierter Strombegrenzungsfunktion am ersten Ende des Stromversorgungspfads bestimmte Stromstärke I₂ [D_on].

The specific, in particular measured, values can include, for example:

• - the voltage U ₁ [D _off ] determined at the first end of the power supply path when the current limiting function is deactivated, designated D _off ;
• - the voltage U ₁ [D _on ] determined at the first end of the power supply path when the current limiting function is activated, designated D _on ;
• - the voltage U ₂ [D _off ] determined at the second end of the power supply path when the current limiting function is deactivated;
• - the voltage U ₂ [D _on ] determined at the first end of the power supply path when the current limiting function is activated;
• - the current I ₁ [D _off ] determined at the first end of the power supply path when the current limiting function is deactivated;
• - the current intensity I ₁ [D _on ] determined at the first end of the power supply path when the current limiting function is activated;
• - the current I ₂ [D _off ] determined at the second end of the power supply path when the current limiting function is deactivated; and or
• - the current I ₂ [D _on ] determined at the first end of the power supply path when the current limiting function is activated.

• - die Spannungsdifferenz ΔU [D_off] = U₁ [D_off] - U₂ [D_off]; und/oder
• - die Spannungsdifferenz ΔU [D_on] = U₁ [D_on] - U₂ [D_on].

The derived values may include, for example:

• - the voltage difference ΔU [D _off ] = U ₁ [D _off ] - U ₂ [D _off ]; and or
• - the voltage difference ΔU [D _on] = U ₁ [D _on] - U ₂ [D _on ].

The status of the current limiting function, in particular “activated” / “on” and “deactivated” / “off”, can also be determined.

The relations can link one or more of the determined and/or derived values, for example, using the relation symbols =, #, >, ≥, <, ≤. When you insert the values into the relations, the result is the statement TRUE / “Relation applies” or FALSE / “Relation does not apply”.

For example, a relation can be “I ₁ [D _off ] = I ₂ [D _off ]” or the associated query “I ₁ [D _off ] = I ₂ [D _off ]?” If the measured current values I ₁ [D _off ] and I ₂ [D _off ] are the same, at least within permitted tolerances, the relation applies. If the measured current values deviate from one another even taking into account permitted tolerances, the relation does not apply. Since physically I ₁ [D _off ] = I ₂ [D _off ] must apply, if this relation applies based on the measured values, this indicates that the current measurements are reliable.

The error-relevant action can, for example, issue a note to the driver of the vehicle, to a service point (such as a workshop) and / or to a manufacturer of the vehicle, save a note in an error memory, send a signal to a higher-level module with a note the improper functioning, a total or partial deactivation with respect to some of its functions of the at least one electrical component connected to this power supply path, etc. For example, in the case of an incorrect current measurement, the identified, incorrect current measurement can be ignored for a short time in a further development in order to ensure reliable operation of the connected functional component.

However, at least one action can also be triggered if the result of the check for at least one relation indicates a proper determination, in particular measurement, of the voltage and/or current and/or a proper activation of the current limiting function tet, e.g. an entry in a data memory or sending a signal to a higher-level module indicating proper function.

When the current limiting function is activated, the electrical current is specifically limited by the at least one power supply path, in particular to a predetermined maximum value. The current limiting function can, for example, be activated and deactivated using software.

The proper determination of a voltage and/or a current can include determining it without errors and with sufficient precision, in particular measuring it, or the associated measuring device(s) working without errors and with sufficient precision. Proper activation of the current limiting function may include limiting the current through the power supply path to the specified level with activation.

It is an embodiment that at least one relation only includes measured currents, i.e. it is checked whether at least one predetermined relation applies to current values determined as part of the test process.

It is a further development that such at least one relation includes at least one relation or at least one logically equivalent variation thereof from the following group, which are listed here with a respective interpretation: relation interpretation I ₁ [D _on] = I ₂ [D _on ] Current measurements correctly I ₁ [D _off ] = I ₂ [D _off ] Current measurements correctly I ₁ [D _on] < I ₂ [D _off ] Current limitation and current measurements correctly I ₁ [D _on] ≠ I ₂ [D _on] At least one of the current measurements is incorrect I ₁ [D _off ] ≠ I ₂ [D _off ] At least one of the current measurements is incorrect I ₁ [D _off ] < I ₂ [D _off ] Current measurement I ₁ not correct I ₁ [D _off ] > I ₂ [D _off ] Current measurement I ₂ not correct I ₁ [Don _] < I ₂ [Don] Current measurement I ₂ not correct I ₁ [D _on] > I ₂ [Don] Current measurement I ₁ not correct

It is an embodiment that at least one relation only includes voltage differences derived from the measured voltages, i.e. it is checked whether at least one predetermined relation applies to voltage differences derived as part of the test procedure.

It is a further development that such at least one relation includes at least one relation or at least one logically equivalent variation from the following group, which are listed here with a respective interpretation: relation interpretation ΔU [D _on] ≥ ΔU [D _off ] At least one of the voltage measurements U ₁ and/or U ₂ and/or the current limitation is not correct ΔU [D _on] < ΔU [D _off ] Voltage measurements U ₁ and U ₂ and current limitation correctly ΔU [D _on] < 0 Voltage measurement U ₁ or U ₂ not correct

It is an embodiment that at least one relation is a combination of a relation of the voltage differences derived from the measured voltages and a relation of the measured ones Current values include, i.e. it is checked whether a predetermined relation applies to voltage differences derived during the test process and, in addition, a predetermined relation applies to the current values.

It is a further development that such at least one relation includes at least one relation or at least one logically equivalent variation from the following group, which are listed here with a respective interpretation: relation interpretation (ΔU [D _on] ≥ ΔU [D _off ]) & (I [D _on] < I [D _off ]) At least one of the voltage measurements U ₁ and/or U ₂ is incorrect (ΔU [D _on] ≤ ΔU [D _off ]) & (I [D _on] ≥ I [D _off ]) The referenced current measurement 1 or I ₂ is not correct (ΔU [D _on] ≥ ΔU [D _off ]) & (I [D _on] < I [D _off ]) At least one of the voltage measurements U ₁ and/or U ₂ is incorrect (ΔU [D _on] ≤ ΔU [D _off ]) & (I [D _on] < I [D _off ]) All measurements and current limitation correct (ΔU [D _off ] > ΔU [D _on ]) & (I [D _on] < I [D _off ]) Voltage measurement _U2 not correct

The measured value I corresponds to one of the “referenced” measured values I ₁ or I ₂ .

It is an embodiment that the vehicle is designed to trigger the at least one action if the result of the check for a majority of several relations indicates an incorrect determination of a voltage and/or a current and/or an incorrect activation the degradation function. In this way, the advantage is achieved that the same voltage, the same current or the degradation function can be checked for plausibility using several relations. Only if the majority of these relations or plausibility checks (e.g. two out of two, at least two out of three, at least three out of five, etc.) indicate or come to the conclusion that there is no proper determination or activation, will the at least one action be triggered .

It is an embodiment that an electronic fuse (E-Fuse) is arranged at the first end of the power supply path, by means of which the values of the first voltage and the first current can be measured. This has the advantage that voltage and current measurement can be combined with protection of the power supply path in a simple and inexpensive way. In addition, the measurements carried out using the electronic fuse are comparatively precise.

It is a further development that the electronic fuse is integrated into a power distributor at the first end.

The values of the second voltage and the second current can be measured, for example, by means of the at least one functional component connected to the second end. The measurement accuracies of the measurements at the first end and at the second end of the power supply path may be virtually the same or may be different.

It is an embodiment that the vehicle is set up to trigger the electronic fuse during a test procedure to trigger it (and thus to open the circuit breaker present in the electronic fuse) and to check whether the values and values determined in the context of activating the electronic fuse /or values derived from them at least one predetermined relation applies, which provides an indication of whether the electronic fuse can be controlled properly. This advantageously results in more reliable protection of power supply paths in the on-board power system. This embodiment can be implemented specifically if the function of the at least one component connected to the power supply path can be dispensed with for the duration of the check or test procedure or if there is an alternative power supply for this at least one component. An error-relevant message can then be output in the same way.

The at least one relation can, for example, be at least one relation from the group relation interpretation ΔU [D _on ] = U ₁ Electronic fuse triggered properly ΔU [D _off ] = U ₁ Electronic fuse not closed properly I [D _off ] = 0 Electronic fuse not closed properly I [D _on] = 0 Electronic fuse triggered properly I [D _on] > 0 Electronic fuse not triggered properly
or logically equivalent variations thereof, where D _on then denotes the control for tripping and D _off the control for closing. In addition, U1 [D _off ] = U1 [D _on] = U ₁ .

• - Werte einer ersten Spannung und eines ersten Stroms an einem ersten Ende des Stromversorgungspfads jeweils bei aktivierter und deaktivierter Strombegrenzungsfunktion bestimmt werden,
• - Werte einer zweiten Spannung und eines zweiten Stroms an einem zweiten Ende des Stromversorgungspfads jeweils bei aktivierter und deaktivierter Strombegrenzungsfunktion bestimmt werden,
• - überprüft wird, ob für die so bestimmten Werte und/oder daraus abgeleitete Werte mindestens eine vorgegebene Relation zutrifft, und
• - mindestens eine fehlerrelevante Aktion ausgelöst wird, falls das Ergebnis der Überprüfung für mindestens eine Relation auf ein nicht ordnungsgemäßes Bestimmen, insbesondere Messen, mindestens einer Spannung und/oder mindestens eines Stroms und/oder auf eine nicht ordnungsgemäße Aktivierung der Strombegrenzungsfunktion hindeutet.

The task is also solved by a method for carrying out a test sequence for diagnosing measurements on a power supply path of an on-board power system of a vehicle, in which

• - Values of a first voltage and a first current are determined at a first end of the power supply path with the current limiting function activated and deactivated,
• - Values of a second voltage and a second current are determined at a second end of the power supply path with the current limiting function activated and deactivated,
• - it is checked whether at least one specified relation applies to the values determined in this way and/or values derived therefrom, and
• - at least one error-relevant action is triggered if the result of the check for at least one relation indicates improper determination, in particular measurement, of at least one voltage and/or at least one current and/or improper activation of the current limiting function.

The method can be designed analogously to the vehicle and vice versa, and has the same advantages.

It is an embodiment that the method is carried out after starting the vehicle and/or when the vehicle is at a standstill. This has the advantage that possible effects of the test procedure are kept to a minimum and, in particular, occupants of the vehicle do not notice that the test procedure is being carried out. This also makes it possible to check power supply paths to functional components that may not be able to be tested when the vehicle is in motion for safety-related reasons, for example a braking system, a steering system and/or a lighting system.

• 1 zeigt eine vereinfachte Skizze eines Energiebordnetzes eines Fahrzeugs;
• 2 zeigt einen Ausschnitt aus der Skizze aus 1;
• 3 zeigt eine Auftragung einer Strombegrenzungsfunktion D gegen die Zeit t in s;
• 4 zeigt eine Auftragung eines Stroms I_e-fuse an einem ersten Ende eines Stromversorgungspfads des Energiebordnetzes aus 1 gegen die Zeit t in s;
• 5 zeigt eine Auftragung eines Stroms I_load an einem zweiten Ende des Stromversorgungspfads des Energiebordnetzes aus 1 gegen die Zeit t in s;
• 6 zeigt eine Auftragung einer Spannung U_e-fuse an dem ersten Ende des Stromversorgungspfads des Energiebordnetzes aus 1 gegen die Zeit t in s; und
• 7 zeigt eine Auftragung einer Spannung U_load an dem zweiten Ende des Stromversorgungspfads des Energiebordnetzes aus 1 gegen die Zeit t in s.

The characteristics, features and advantages of this invention described above and the manner in which they are achieved will be more clearly and clearly understood in connection with the following schematic description of an exemplary embodiment, which will be explained in more detail in connection with the drawings.

• 1 shows a simplified sketch of an on-board energy network of a vehicle;
• 2 shows an excerpt from the sketch 1 ;
• 3 shows a plot of a current limiting function D versus time t in s;
• 4 shows a plot of a current I _e-fuse at a first end of a power supply path of the on-board power system 1 versus time t in s;
• 5 shows a plot of a current I _load at a second end of the power supply path of the on-board power system 1 versus time t in s;
• 6 shows a plot of a voltage U _e-fuse at the first end of the power supply path of the on-board power system 1 versus time t in s; and
• 7 shows a plot of a voltage U _load at the second end of the power supply path of the on-board power system 1 against time t in s.

1 shows a simplified sketch of an on-board power system 1 of a vehicle F. The on-board electrical system 1 has, purely as an example, a generator 2 (e.g. a starter generator) and a battery 3, the negative poles of which are connected via screwed power lines Ls to a body 4 of the vehicle F, which serves as a reference potential.

A positive pole of the battery 4 is connected via a further screwed power line Ls to a first power distributor 5, which is connected to a second power distributor 6 via a further screwed power line Ls. Further components of the vehicle electrical system 1 can be connected to the first power distributor 5 (not shown). The second power distributor 6 is also connected to a positive pole of the generator 2 via a screwed power line Ls and connected to a consumer 7 via a cable 8. The consumer 7 is connected to the body 4 via a power line Lst.

In the present case, there is, among other things, a power supply path SVP between the second power distributor 6 and the consumer 7, which includes the cable 8, a first electrical plug connection S1 of the cable 8 with the second power distributor 6 and a second electrical plug connection S2 of the cable 8 with the second power distributor 6 .

The power supply path SVP and thus the consumer 7 are protected via an electronic fuse 12 integrated into the second power distributor 6, on which the voltage U _e-fuse applied thereto as well as the current I e- flowing through it and thus also through the power supply path _{SVP fuse} can be measured, see 2 . A voltage measuring device and also a current measuring device are thus functionally integrated into the electronic fuse 12. Other lines or branches of the second power distributor 6 can also be protected with respective electronic fuses (not shown).

The consumer 7 is set up to measure the voltage U _load and the current I _load at the other end of the power supply path SVP.

The electronic fuse 12 and the consumer 7 are connected via data lines 9 to an evaluation device, here for example in the form of an on-board computer 10. The on-board computer 10 receives the voltages U _e-fuse and U _load and the currents I _e-fuse and I _load or their measured values via the data lines 9. The on-board computer 10 can also calculate values derived therefrom, such as the voltage difference ΔU = U _e-fuse - U _load , etc.

2 shows a section of the second power distributor 6 of the vehicle electrical system 1. The electronic fuse 12 is connected via a line path 14 to a plug-in connection element 15 of the first plug-in connection S1 and a mating plug-in connection element 16 of the first plug-in connection S1 is connected to the cable 8. The plug connection element 15 can be integrated, for example, into a housing of the second power distributor.

The second power distributor 6 also has an output to the first power distributor 5 and at least one further power supply output, as indicated here to a consumer 11.

Analogous to the power supply path SVP, voltages or voltage differences can in principle also be measured on any other power supply paths of the on-board power system 1. For example, the generator 2, the battery 3, the first power distributor 5, other consumers, etc. can also be provided with respective measuring devices (not shown) and connected to the on-board computer 10 via the data lines 9.

Returning to again 1 the on-board computer 10 is set up to selectively activate and deactivate a current limiting function D for the power supply path SVP described as an example, as in 3 indicated. The current limiting function D is switched on at time t _on and is therefore switched off for times t < t _on , as represented by D = D _off = 0, and is switched on for times t > t _on , as represented by D = D _on = 1.

It is assumed that by switching on the current limiting function D, a comparatively higher current for times t < t _on should be limited to a value I _max through the power supply path SVP for t > t _on , from a physical point of view both at the electronic fuse 12 and on the consumer 7, as in 4 by limiting the flow through the electronic fuse 12 Current I _e-fuse to I _max or in 5 by limiting the current I _load fed into the consumer 7 to I _max .

As in 6 shown, when the current limiting function D is activated, the voltage U _e-fuse measured at the electronic fuse 12 increases, as does the voltage U _load at the consumer end of the power supply path SVP, as in 7 indicated. Due to the ohmic resistance of the power supply path SVP, the relation U _e-fuse > U _load physically applies, which can also be expressed as ΔU = U _e-fuse - U _load > 0. Furthermore, the relation ΔU [D _off ] > ΔU [D _on] should apply.

Furthermore, the on-board computer 10 is set up to carry out a test procedure and, as part of the test procedure, before activating the current limiting function D (i.e. at D = D _off ), the measured values of I _e-fuse [D _off ], I _load [D _off ], U _e-fuse [D _off ] and U _load [D _off ], activate the current limiting function D and subsequently the measured values of I _e-fuse [D _on ], I _load [D _on ], U _e-fuse [D _on] and U _load [D _on].

Furthermore, the on-board computer 10 is set up to check whether for at least some of the values determined as part of the test procedure I _e-fuse [D _off ], I _load [D _off ], U _e-fuse [D _off ], U _load [ D _off ], I _e-fuse [D _on ], I _load [D _on ], U _e-fuse [D _on] and U _load [D _on] and/or values derived therefrom such as ΔU [D _off ] and ΔU [D _on] at least one specified relation applies and at least one error-relevant action is triggered if the result of the check for at least one relation indicates an incorrect determination of the voltage and / or the current and / or an incorrect activation of the current limiting function.

In addition, the on-board computer 10 can be set up to trigger the electronic fuse 12 during the test process and to check whether the values U _e-fuse , I _e-fuse , U _load , I _load and/or values ΔU [D _off ], ΔU [D _on] derived therefrom, at least one predetermined relation applies, which provides an indication of whether the electronic fuse 12 can be controlled properly.

Of course, the present invention is not limited to the exemplary embodiment shown.

In general, “a”, “an” etc. can be understood to mean a singular or a plural, in particular in the sense of “at least one” or “one or more” etc., as long as this is not explicitly excluded, e.g. by the expression “exactly on” etc.

Reference symbol list

1

On-board electrical system

2

generator

3

battery

4

body

5

First power distributor

6

Second power distributor

7

consumer

8th

Cable

9

Data line

10

On-board computer

11

consumer

12

Electronic backup

14

conduction path

15

Plug connection element

16

Plug connection mating element

D

Current limiting function

Doff

Disabled current limiting function

Don

Enabled current limiting function

F

vehicle

Ie-fuse

Current through the electronic fuse

Iload

electricity to the consumer

Imax

Maximum current with current limiting function activated

Ls

Screwed power cable

Lst

power line

SVP

Power supply path

S1

First plug connection

S2

Second plug connection

Ue fuse

Voltage at the electronic fuse

Uload

Voltage at the consumer

t

Time

volume

Time of activation of the current limiting function

ΔU

voltage difference

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102019120567 A1 [0005]
• DE 102020106210 A1 [0006]

Claims (10)

Vehicle (F) with an on-board power supply system (1) which has at least one power supply path (SVP) to at least one electrical component (7, 11), the vehicle (F) being set up to have a current limiting function (D) for the at least one Power supply path (SVP) to selectively activate or deactivate, - values of a first electrical voltage (U _e-fuse ) and a first electrical current (I _e-fuse ) at a first end (12) of the power supply path (SVP), each with activated ( D _on ) and not activated (D _off ) current limiting function (D) to determine - values of a second electrical voltage (U _load ) and a second electrical current (I _load ) at a second end of the power supply path (SVP), respectively when activated and deactivated to determine the current limiting function (D), - as part of a test procedure, to determine at least some of the values when the current limiting function (D) is activated (D _on ) and not activated (D _off ), - to check whether the values determined as part of the test procedure ( U _e-fuse , I _e-fuse , U _load , I _load ) and/or values derived therefrom (ΔU) if at least one predetermined relation applies, and - trigger at least one action if the result of the check for at least one relation is at least one improper determination of a voltage (U _e-fuse , U _load ) and/or a current (I _e-fuse , I _load ) and/or indicates improper activation of the current limiting function (D). vehicle (F). Claim 1 , where at least one relation only includes measured electrical currents (I _e-fuse , I _load ). Vehicle (F) according to one of the preceding claims, wherein at least one relation comprises voltage differences (ΔU) derived only from the measured voltages (U _e-fuse , U _load ). Vehicle (F) according to one of the preceding claims, wherein at least one relation is a combination of a relation of the voltage differences (ΔU) derived from the measured voltages (U _e-fuse , U _load ) and a relation of the measured electrical currents (I _e-fuse , I _load ). Vehicle (F) according to one of the preceding claims, wherein the vehicle (F) is designed to trigger the at least one action if the result of the check for a majority of several relations points to the same incorrect determination of a voltage (U _e-fuse , U _load ) and/or a current (I _e-fuse , I _load ) and/or indicates improper activation of the current limiting function (D). Vehicle (F) according to one of the preceding claims, wherein an electronic fuse (12) is arranged at the first end of the power supply path (SVP), by means of which the values of the first voltage (U _e-fuse ) and the first current (I _{e- fuse} ) can be measured. vehicle (F). Claim 6 , wherein the vehicle (F) is designed to trigger the electronic fuse (12) during the test process and to check whether the values (U _e-fuse , I _{e -fuse} , U _load , I _load ) and/or values derived therefrom (ΔU) at least one predetermined relation applies, which provides an indication of whether the electronic fuse (12) can be controlled properly. Vehicle (F) according to one of the preceding claims, wherein the vehicle (F) is a partially or fully autonomous vehicle (F), in particular a fully electrically driven vehicle (F). Method for carrying out a test sequence for diagnosing measurements on a power supply path (SVP) of an on-board power system (1) of a vehicle (F), in which - values of a first voltage (U _e-fuse ) and a first current (I _e-fuse ). a first end of the power supply path (SVP) are determined with the current limiting function (D) activated (D _on ) and deactivated (D _off ), - values of a second voltage (U _load ) and a second current (I _load ) at a second end of the Power supply path (SVP) are determined with the current limiting function (D) activated (D _on ) and deactivated (D _off ), - it is checked whether for the values determined in this way (U _e-fuse , I _e-fuse , U _load , I _load ) and/or values derived therefrom (ΔU) at least one specified relation applies, and - at least one error-relevant action is triggered if the result of the check for at least one relation indicates an incorrect determination of at least one voltage (U _e-fuse , U _load ) and/or at least one current (I _e-fuse , I _load ) and /or indicates improper activation of the current limiting function (D). Procedure according to Claim 9 , whereby the test procedure is carried out after starting the vehicle (F) and/or when the vehicle (F) is at a standstill.

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