Method for operating a motor vehicle locking system

Abstract

The invention relates to a method for operating a motor vehicle locking system (1), the motor vehicle locking system (1) having a drive device (2) with an electric drive motor (3), and a control assembly (4) which actuates the drive device (2) in order to provide an electromotive locking function for an adjustable closing element (5) of the motor vehicle (6), according to the invention, the control assembly (4) has a rechargeable electrical energy store (10) having at least one capacitor (11), an emergency supply voltage being supplied to the drive (2) by means of the energy store (10) during emergency operation.

Description

Technical Field

[0001] The invention relates to a method for operating a motor vehicle locking system according to the preamble of claim 1 , a control assembly for operating a motor vehicle locking system according to the preamble of claim 13 , and a motor vehicle locking system according to claim 14 . Background Art

[0002] The motor vehicle locking system in question is used for all types of electric locking functions of closing elements of a motor vehicle. This includes in particular closing elements such as side doors, rear doors, trunk lids, luggage compartment lids, hoods, etc. These closing elements can basically be designed as swing doors or sliding doors.

[0003] The electric locking function particularly relates to a motor vehicle lock associated with a motor vehicle locking system, which has a locking pin and a locking pawl as locking elements. The locking pin can be moved into a locked position, in which it remains engaged with the locking element and is secured in this position by the locking pawl. The motor vehicle lock is also equipped with an electric drive, which can be used to raise the locking pawl so that the locking pin can be adjusted to its open position, thereby releasing the locking element.

[0004] To meet the requirements for the safety of the voltage supply of such motor vehicle locks, a rechargeable energy store can be provided, thereby ensuring that the motor vehicle locking system is supplied with electrical energy via the emergency supply voltage even in emergency operation, in particular when the normal supply voltage fails.

[0005] The prior art (DE 10 2014 105 874 A1) on which the present invention is based relates to a method for operating a vehicle locking system with a vehicle lock, wherein the energy storage device associated with the vehicle lock can include a double-layer capacitor. The use of a double-layer capacitor enables a high power output for emergency operation of the vehicle lock.

[0006] The challenge here is to ensure that the energy storage device remains usable throughout the entire service life of the vehicle locking system in order to meet safety requirements. In principle, diagnostic routines can be provided for the energy storage device (here, a capacitor) to determine electrical characteristic values, such as the equivalent series resistance (ESR) and the capacitor's capacitance. Unexpected changes in these characteristic values ​​can indicate that the capacitor is damaged due to aging, damage, or similar reasons. Therefore, the accuracy of the determination of these characteristic values ​​is crucial. Summary of the Invention

[0007] The present invention is based on the problem of developing and expanding the known method in such a way that the reliability of the diagnosis of the energy store is further improved.

[0008] This problem is solved by the features of claim 1 .

[0009] The present invention is based on the premise that capacitors are subject to dynamic self-discharge. This fundamental understanding is crucial: self-discharge can significantly influence the determination of electrical characteristic values ​​during diagnosis. The discharge current (inflow current) resulting from self-discharge consists of a leakage current (leakage current), which is essentially dependent on the capacitor voltage, and a component that is attributed to the dielectric absorption of the capacitor and therefore exhibits time-dependent relaxation effects. Therefore, self-discharge depends on the capacitor's conditions prior to diagnosis, making it difficult to easily correct for self-discharge during diagnosis. If a capacitor is charged, for example, with a high voltage jump, then high self-discharge may occur due to dielectric absorption, which distorts the determination of the ESR or capacitance.

[0010] In detail, it is proposed that: a diagnostic routine is executed with the aid of a control component, in which the time profile of the capacitor voltage during capacitor self-discharge is monitored with respect to whether a predetermined attenuation criterion is met, and a measurement routine is triggered with the aid of the control component based on whether the attenuation criterion is met, in which at least one electrical characteristic variable of the capacitor is determined.

[0011] The proposed solution effectively prevents self-discharge from falsifying the diagnosis, as the diagnosis is preceded by a wait for the dielectric absorption to have largely decayed. However, the waiting time is not fixed here; rather, the measurement routine is triggered based on the time profile of the capacitor voltage using a decay criterion to reduce delays.

[0012] Particularly preferred embodiments according to claims 3 to 5 involve monitoring during repeated charging routines, which represent recharging of the capacitor to compensate for self-discharge. Due to the decay of dielectric absorption, the self-discharge decreases, and the intervals between charging routines increase, allowing measurement routines to be triggered based on the time component of the charging routine. These embodiments are particularly practical because the capacitor can be kept at a high state of charge during diagnostics and thus be used for emergency operations that may occur unexpectedly.

[0013] Claims 6 to 8 provide further preferred embodiments in which the temporal behavior of the capacitor voltage is monitored when the capacitor terminals are open-circuited. By analyzing the self-discharge behavior, it is possible to infer whether the self-discharge has sufficiently relaxed. In particular, a self-discharge model can be used for this analysis, allowing the capacitor to be characterized based on its self-discharge behavior.

[0014] Generally speaking, the self-discharge behavior can also indicate a fault state of the capacitor, which is the subject of claim 11 .

[0015] According to another teaching of claim 13, which is to be given independent significance, a control assembly for operating a motor vehicle locking system is claimed. Essentially, the control assembly performs a diagnostic routine in which the temporal profile of the capacitor voltage during capacitor self-discharge is monitored for fulfillment of a predetermined decay criterion, and, upon fulfillment of the decay criterion, triggers a measurement routine in which at least one electrical characteristic variable of the capacitor is determined. Reference is made to all explanations regarding the proposed method.

[0016] According to another teaching of claim 14, which is also to be regarded as an independent invention, protection is claimed for a motor vehicle locking system having a drive device with an electric drive motor and a proposed control assembly for actuating the drive device. The motor vehicle locking system can be configured to carry out the proposed method. Reference is made to all the explanations regarding the proposed method and the proposed control assembly.

[0017] In a preferred embodiment according to claim 15, a motor vehicle lock is provided for a closure element of a motor vehicle, wherein the electric drive is provided for electrically lifting a locking pawl of the motor vehicle lock. The proposed solution allows for the special safety requirements of motor vehicle locks to be taken into account. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The invention is explained in more detail below with reference to the accompanying drawings, which show only exemplary embodiments.

[0019] Figure 1 A motor vehicle door with a motor vehicle locking system and a motor vehicle lock are shown in corresponding perspective views.

[0020] Figure 2 A schematic diagram showing the control components,

[0021] Figure 3 An exemplary discharge current showing self-discharge over time, and

[0022] Figure 4 An exemplary temporal profile of the capacitor voltage in a diagnostic routine is shown. DETAILED DESCRIPTION

[0023] The invention relates to a method for operating a motor vehicle locking system 1. The motor vehicle locking system 1 comprises a drive device 2 with an electric drive motor 3 and a control assembly 4 which actuates the drive device 2 to provide an electric locking function for an adjustable closure element 5 of a motor vehicle 6.

[0024] The term “drive motor” currently includes all types of electric actuators, in particular rotary and linear actuators. Preferably, the drive motor 3 is a rotary electric motor, which is further preferably configured as a brushed DC motor or a brushless DC motor.

[0025] The electric locking function is understood to mean that the adjustable closure element 5 of the motor vehicle 6 is fixed or released, for example locked or unlocked, directly or indirectly by a movement generated by the electric drive 2, and / or the adjustment element is adjusted, for example opened or closed. With regard to the design of the closure element 5, reference is made to the explanation at the beginning, wherein currently, Figure 1 1 shows the functioning of a motor vehicle locking system 1 for a closure element 5 designed as a side door. However, all explanations apply equally to all other types of closure elements of a motor vehicle 6.

[0026] The control assembly 4 preferably includes control electronics for carrying out the control tasks associated with the electric locking function and is equipped, for example, with a control unit 7, such as a microcontroller. The control assembly 4 is configured to control the electric drive 2 and, in this case, preferably also monitors the occurrence of an operating event, such as an operating signal transmitted from an operating element (e.g., door handle 8). Upon receipt of the operating signal, the control assembly 4 can trigger the operation of the drive 2.

[0027] During normal operation, the drive device 2 can be operated using the normal supply voltage of the motor vehicle 6. The normal supply voltage used during normal operation is preferably provided by the onboard electrical system 9, and in particular by means of the central battery of the motor vehicle 6. The central battery is preferably a battery that provides the electrical energy required for starting the motor vehicle 6 and / or for driving the motor vehicle 6. Accordingly, normal operation is provided when the drive device 2 can be operated using the normal supply voltage.

[0028] The control module 4 has a chargeable electrical energy store 10 with at least one capacitor 11, wherein in emergency operation, an emergency supply voltage ( Figure 2 ). The emergency operation is provided for situations in which the normal supply voltage may not be sufficient for operating the drive device 2. Examples thereof are a failure of the onboard electrical system 9 (e.g. due to a large discharge of the central battery or a fault in an electrical line in the onboard electrical system 9), and a crash of the motor vehicle 6. The emergency supply voltage is provided by means of the capacitor voltage of the capacitor 11 and, in emergency operation, can also be supplied to other components of the control assembly 4, such as the control unit 7, in addition to the drive device 2. The energy storage device 10 is designed to be rechargeable and can be charged by means of the normal supply voltage in normal operation. Preferably, the control assembly 4 is equipped with a charging circuit 12, such as a charging regulator, for charging the energy storage device 10 in normal operation.

[0029] In a particularly preferred embodiment, energy storage device 10 includes at least one double-layer capacitor. Double-layer capacitors have an electrochemical double layer, also known as a "Helmholtz layer." Such double-layer capacitors are also known as "supercapacitors," "ultracapacitors," "supercapacitors," etc. When multiple capacitors 11 are used, they can generally be connected in series and / or in parallel. In addition to the at least one capacitor 11, energy storage device 10 may also include other storage elements, such as primary and / or secondary batteries.

[0030] In a particularly preferred embodiment, the energy store 10 includes a single capacitor 11, in particular a single double-layer capacitor. The energy store 10 may also include a step-up chopper 13 connected downstream of the at least one capacitor 11. The step-up chopper 13 is configured to boost the capacitor voltage of the at least one capacitor 11 to an emergency supply voltage. The voltage output of the step-up chopper 13 can be connected, for example, to a driver unit 14 having an H-bridge for controlling the drive device 2. The driver unit 14 can also be used during normal operation to operate the drive device 2 based on the normal supply voltage. The driver unit 14 is preferably operated here by the control unit 7.

[0031] It is now important to carry out a diagnostic routine with the aid of the control component 4, in which the temporal curve of the capacitor voltage during the self-discharge of the capacitor 11 is monitored with regard to whether a predetermined decay criterion is met, and, depending on whether the decay criterion is met, to trigger a measuring routine with the aid of the control component 4, in which at least one electrical characteristic variable of the capacitor 11 is determined.

[0032] In the measurement routine, the at least one characteristic variable is preferably determined based on a current and / or voltage measurement at capacitor 11, wherein the self-discharge of capacitor 11 is included in the evaluation of the measurement routine. Before triggering the measurement routine, a decay criterion is checked, which indicates that relaxation effects of the self-discharge of capacitor 11, in particular those due to dielectric absorption, have sufficiently decayed. Consequently, the accuracy of the measurement routine is not negatively affected.

[0033] exist Figure 3 The discharge current I in the case of self-discharge of the capacitor 11 is shown schematically and exemplarily in FIG. SE In addition to the leakage current I which is basically dependent on the capacitor voltage leak In addition, there is a significant time-dependent discharge current component. If this time-dependent component decays to a great extent (which is indicated by the decay criterion), it can be approximated that the self-discharge discharge current I SE Being constant or only voltage-dependent, this discharge current can be taken into account in a simple manner in the measurement routine.

[0034] The fulfillment of the attenuation criterion is checked based on the temporal profile of the capacitor voltage. The control assembly 4 has a voltage sensor 15 for measuring the capacitor voltage, which is preferably connected in parallel with the capacitor 11 and transmits the value of the capacitor voltage to the control unit 7. The temporal profile of the capacitor voltage takes into account not only the instantaneous value of the capacitor voltage but also temporally successive values ​​of the capacitor voltage.

[0035] Furthermore, it is preferably provided here that the capacitance of the capacitor 11 and / or the equivalent resistance of the capacitor 11 are determined as electrical characteristic parameters, preferably, the capacitance and / or the equivalent resistance are determined based on the discharge and / or charging of the capacitor 11, and further preferably, the fault routine is triggered when the electrical characteristic parameter meets the characteristic value fault criterion.

[0036] The capacitance and / or equivalent resistance are determined here by current and voltage measurements. For the voltage measurement, the already mentioned voltage sensor 15 can be used. The current measurement allows a quantitative measure of the current flowing into the capacitor 11 (charging) or the current flowing out of the capacitor 11 (discharging), wherein the control component 4 has a current sensor (not shown). Preferably, the equivalent series resistance (ESR) is used to determine the equivalent resistance.

[0037] In order to charge the capacitor 11 during the measurement routine, the control module 4 has a charging circuit 12. The charging circuit 12 is preferably the already mentioned charging circuit 12 provided for charging the capacitor 11 during normal operation.

[0038] The discharge of the capacitor 11 during the measurement routine is a targeted discharge in addition to the self-discharge. In this case, and preferably, the control unit 4 has Figure 2 A discharge circuit (not shown) is used to charge capacitor 11. The discharge circuit may, for example, include a discharge resistor through which capacitor 11 is discharged. Other designs of the discharge circuit are conceivable. For example, to discharge, drive device 2 may be controlled, for example, in the opposite direction of the drive provided for the electric locking function, so that drive motor 3 is placed in blocking operation for discharge. Discharge to onboard electrical system 9 of motor vehicle 6 is also conceivable.

[0039] Furthermore, it is preferably provided that, in the diagnosis routine, a charging routine triggered by a charging criterion is repeatedly executed by means of the control component 4 , in which the capacitor 11 is charged to the rated capacitor voltage U1 , the charging routine is terminated and the fulfillment of the charging criterion is monitored again, preferably the decay criterion being determined based on the time component of the execution of the charging routine. Figure 4 In FIG. 1 , the temporal profile of the capacitor voltage resulting from a repeated charging routine is shown by way of example and diagrammatically.

[0040] The charging routine can be a measure provided during normal operation to ensure that capacitor 11 approximately reaches the rated capacitor voltage U1. To prevent continuous charging, a charging criterion is set that triggers charging or recharging of capacitor 11. After reaching the rated capacitor voltage U1, the charging routine ends, allowing the capacitor voltage to subsequently decrease again due to self-discharge. If the charging criterion is met again, the charging routine is triggered again. Accordingly, monitoring of the charging criterion and execution of the charging routine are repeated.

[0041] like Figure 4 As shown in , it is here and preferably provided that the charging criterion is defined based on the capacitor voltage, in particular by triggering the charging routine when the capacitor voltage falls below a threshold voltage U2. Figure 4 In FIG, the charging routine is performed in the shaded time intervals. Between the shaded time intervals, there is a voltage drop due to self-discharge.

[0042] Furthermore, it is preferably provided here that the decay criterion is defined based on the point in time at which the charging routine is triggered. Figure 3 As can be seen from the figure, the duration from the triggering of the charging routine to the next triggering due to the voltage falling below the threshold voltage U2 gradually becomes longer (Δt1, Δt2, Δt3), because the discharge current I SE The leakage current I tends to decrease over time and approaches a nearly constant value, especially for a given capacitor voltage. leak (See Figure 3 ).

[0043] In this case, the decay criterion is preferably defined based on the duration Δt1, Δt2, Δt3 between the triggering times and / or based on the frequency of the triggering of the charging routine. For the duration, the decay criterion can include, for example, an absolute criterion (exceeding a minimum duration) and / or a relative criterion (below a maximum change in duration). The frequency is the inverse of the duration between the triggering times. Absolute criterion (below a maximum frequency) and / or relative criterion (below a maximum change in frequency) are also conceivable here. Furthermore, the decay criterion can be defined based on the duration from the end of a charging routine to the triggering of the next charging routine.

[0044] The aforementioned monitoring of the temporal profile of the capacitor voltage during the time-segmented execution of the charging routine has the advantage that the capacitor voltage can be kept close to the nominal capacitor voltage U2, so that a sufficient amount of energy is available in a safe manner during the transition to emergency operation. By defining a decay criterion based on the time component of the execution of the charging routine, an indirect measure of the self-discharge can be used to trigger the measuring routine.

[0045] In another embodiment, control unit 4 is used during a diagnostic routine to monitor the temporal profile of the capacitor voltage when the connection to capacitor 11 is open. With the connection open, capacitor 11 is neither charged nor actively discharged, other than by self-discharge. Capacitor 11 is preferably held with the connection open for at least 5 minutes, in particular at least 10 minutes, while the temporal profile of the capacitor voltage is monitored.

[0046] In a particularly simple embodiment, the decay criterion is defined by the time variation of the capacitor voltage falling below a predetermined threshold value. For example, after a predetermined time period has elapsed since the start of monitoring, it is checked by how much the capacitor voltage has dropped. The time derivative of the time variation of the capacitor voltage can also be used.

[0047] In another embodiment, the time profile of the capacitor voltage is stored by means of control component 4 and the decay criterion is checked based on a predefined self-discharge model of capacitor 11. The self-discharge model can be used to describe and determine, for example, the proportion of the discharge current that is traceable to leakage currents and dielectric absorption.

[0048] The decay criterion may depend on the transition of the charge state of the capacitor 11 prior to the diagnostic routine. Figure 4 As shown in , if there is a voltage difference in the capacitor voltage prior to the diagnostic routine caused by charging or discharging, a decay criterion can be defined based on this voltage difference. In particular, a change in the nominal capacitor voltage occurs, for example, when an operating mode (parking mode) of motor vehicle 6 with a nominal capacitor voltage is changed to an operating mode (driving mode) with a higher nominal capacitor voltage. The resulting voltage difference can be incorporated into the decay criterion.

[0049] Furthermore, it is preferably provided that the diagnostic routine is executed upon the occurrence of a predetermined triggering event. For example, the triggering event can be time-controlled and, in particular, a predetermined time course starting with a start event. It is conceivable that the start event is the start of a driving operation, in particular the start of a driving drive of motor vehicle 6. It is further conceivable that the triggering event occurs periodically at predetermined time intervals. Similarly, the triggering event can occur depending on the charge state of capacitor 11. For example, the triggering event is defined by a limit voltage for the capacitor voltage.

[0050] The trigger event can occur due to a change in the charge state of capacitor 11, in particular with charging to the rated capacitor voltage. During this charge state change, a particularly high self-discharge can occur, making it particularly advantageous to check the attenuation criterion. The trigger event can occur due to the aforementioned change in the rated capacitor voltage.

[0051] Furthermore, it is preferably provided here that the temporal behavior of the capacitor voltage is checked by means of the control component 4 for fulfillment of a self-discharge fault criterion and that a fault routine is triggered depending on whether the self-discharge fault criterion is fulfilled. The self-discharge fault criterion may represent excessive self-discharge of the capacitor 11 .

[0052] Furthermore, it is preferably provided that the characteristic value fault criterion and / or the self-discharge fault criterion are checked based on a temperature value. The temperature value may represent the temperature of control component 4 , in particular the temperature of capacitor 11 . Control component 4 may include a temperature sensor for determining the temperature value. It is also conceivable that control component 4 receives the temperature value of the surrounding environment of motor vehicle 6 , for example from a central motor vehicle control unit. Another example of environmental information is the operating state of motor vehicle 6 .

[0053] According to another teaching, a control component 4 for operating a motor vehicle locking system 1 is proposed, wherein the motor vehicle locking system 1 has a drive device 2 with an electric drive motor 3, and the control component 4 is configured to control the drive device 2 in order to provide an electric locking function for an adjustable closing element 5 of a motor vehicle 6, wherein the control component 4 has a rechargeable electrical energy storage device 10, which has at least one capacitor 11, wherein the energy storage device 10 provides an emergency supply voltage in emergency operation.

[0054] In this case, it is provided that the control component 4 executes a diagnostic routine in which the temporal profile of the capacitor voltage during the self-discharge of the capacitor 11 is monitored with respect to whether a predetermined decay criterion is met, and the control component 4 triggers a measuring routine, in which at least one electrical characteristic variable of the capacitor 11 is determined, depending on whether the decay criterion is met. Reference is made to all the explanations concerning the proposed method.

[0055] According to another teaching, a motor vehicle locking system 1 is provided, which has a drive device 2 with an electric drive motor 3 and a proposed control assembly 4 for actuating the drive device 2. The motor vehicle locking system 1 is preferably configured to carry out the proposed method. Reference is made to all explanations regarding the proposed method and the proposed control assembly 4.

[0056] Particularly preferred and Figure 1 1 shows a design of a motor vehicle locking system 1, in which a motor vehicle lock 16 is provided for a closure element 5 of a motor vehicle 6. The motor vehicle lock 16 is equipped with a locking pin 17 for engaging with the locking part and a locking pawl 18 associated with the locking pin 17. Figure 1 The locking mechanism is shown in a partially disassembled perspective view and is designed to have a pivotable locking pin 17 for engaging with a locking member not shown. The locking member can be a locking clamp, a locking bolt, etc. Figure 1 In the embodiment of the present invention, the locking pin 17 is in the open position, in which the locking element can be inserted into the locking element receptacle 19 of the locking pin 17. For example, the motor vehicle lock 16 is arranged on the closure element 5, while the locking element is arranged on the motor vehicle 6 in a body-mounted manner. Particularly preferably, the proposed control assembly 4 is integrated together with the energy storage device 10 in a housing 20 of the motor vehicle lock 16, which also accommodates the locking element.

[0057] The locking pawl 18 is in particular part of a locking pawl system 18 with a plurality of locking pawls 18 and can be brought into a locked state (not shown) in which the locking pawl 18 holds the locking pin 17 in the locked position. In principle, a plurality of locked positions can be provided, for example a pre-locking position and a main locking position. Figure 1 Starting from the open position in, these locked positions can be reached by pivoting the locking pin 17 counterclockwise, whereby the locking pawl 18 can fall into a locking engagement with the main notch 21 (main locking position) or the pre-notch 22 (pre-locking position) of the locking pin 17.

[0058] The drive device 2 is preferably configured to electrically lift the pawl 18. The pawl 18 can be brought into the open position by means of the electric drive motor 3, whereby the pawl 18 releases the locking pin 17. For this purpose, the drive motor 3 is connected to the pawl 18 via the drive train 23 of the drive device 2. In emergency operation, the function of the drive device 2 as an opening drive is ensured by means of the energy storage device 10.

[0059] As an alternative to the aforementioned integration of the control assembly 4 into the motor vehicle lock 16, it is conceivable that the control assembly 4 is part of a separate control device 24 for the motor vehicle lock 16. Examples of such control devices 24 are flap controls and door controls, which can also take over other electronic functions in the closure element 5. However, the control device 24 is not necessarily part of the motor vehicle locking system 1.

[0060] In principle, it is conceivable that the drive device 2 assumes an alternative or additional locking function of the vehicle lock 16, for example, unlocking and / or locking a mechanical operating chain of the vehicle lock 16. In addition to or as an alternative to the locking function of the vehicle lock 16 explained in detail here, the vehicle locking system 1 can also include a drive assembly for motorized adjustment of the aforementioned closure element 5 of the vehicle 6, wherein the drive assembly serves to motorized adjustment, in particular, opening and / or closing, of the closure element 5. Other examples of locking functions are motorized adjustment of operating elements of the vehicle 6 as well as interior and exterior elements, such as a fan element, interior rearview mirror, side mirrors, lighting, etc.

Claims

1. A method for operating a motor vehicle locking system (1), wherein: The motor vehicle locking system (1) comprises a drive device (2) with an electric drive motor (3) and a control unit (4) which actuates the drive device (2) in order to provide an electric locking function for an adjustable closure element (5) of the motor vehicle (6). The control component (4) has a chargeable electrical energy store (10) having at least one capacitor (11), wherein an emergency supply voltage is provided for the drive device (2) by means of the energy store (10) during emergency operation, characterized in that: A diagnostic routine is executed with the aid of the control component (4), in which the temporal profile of the capacitor voltage during self-discharge of the capacitor (11) is monitored with respect to whether a predetermined decay criterion is met, and a measurement routine is triggered with the aid of the control component (4) based on whether the decay criterion is met, in which at least one electrical characteristic variable of the capacitor (11) is determined.

2. The method according to claim 1, characterized in that The capacitance of the capacitor (11) and / or the equivalent resistance of the capacitor (11) are determined as electrical characteristic parameters, preferably, the capacitance and / or the equivalent resistance are determined based on the discharge and / or charging of the capacitor (11), and further preferably, a fault routine is triggered when the electrical characteristic parameter meets a characteristic value fault criterion.

3. The method according to claim 1 or 2, characterized in that A charging routine triggered by a charging criterion is repeatedly executed in the diagnostic routine by means of the control component (4), in which the capacitor (11) is charged to a rated capacitor voltage, the charging routine is terminated and monitoring is performed to determine whether the charging criterion is met again, preferably the decay criterion being determined based on a time component of the execution of the charging routine.

4. The method according to claim 3, characterized in that The charging criterion is defined based on the capacitor voltage, in particular by triggering the charging routine when the capacitor voltage is below a threshold voltage.

5. The method according to claim 3 or 4, characterized in that The attenuation criterion is defined based on the time points of triggering the charging routine, preferably based on the duration between the triggering time points and / or based on the frequency of triggering the charging routine.

6. The method according to claim 1 or 2, characterized in that The control component (4) is used in the diagnosis routine to monitor the temporal profile of the capacitor voltage when the capacitor (11) connection is open-circuited.

7. The method according to claim 6, characterized in that The attenuation criterion is defined by the temporal change of the capacitor voltage falling below a predetermined threshold value.

8. The method according to claim 6 or 7, characterized in that The time profile of the capacitor voltage is stored by means of the control component (4), and the attenuation criterion is checked based on a predefined self-discharge model of the capacitor (11).

9. The method according to any one of the preceding claims, characterized in that The decay criterion depends on the change in the charge state of the capacitor (11) before the diagnosis routine, preferably on a voltage difference of the capacitor voltage caused by charging or discharging before the diagnosis.

10. The method according to any one of the preceding claims, characterized in that The diagnostic routine is executed upon the occurrence of a predetermined trigger event, preferably occurring in a time-controlled manner and / or upon a change in the charge state of the capacitor (11), in particular with a change in the setpoint capacitor voltage.

11. The method according to any one of the preceding claims, characterized in that The control component (4) is used to check the temporal behavior of the capacitor voltage with respect to whether a self-discharge fault criterion is met, and a fault routine is triggered depending on whether the self-discharge fault criterion is met.

12. The method according to claim 2 and / or 11, characterized in that The characteristic value fault criterion and / or the self-discharge fault criterion are checked based on a temperature value.

13. A control unit for operating a locking system (1) of a motor vehicle, wherein: The motor vehicle locking system (1) has a drive device (2) with an electric drive motor (3), and the control component (4) is configured to control the drive device (2) in order to provide an electric locking function for an adjustable closure element (5) of the motor vehicle (6), wherein the control component (4) has a chargeable electrical energy storage device (10) having at least one capacitor (11), wherein the energy storage device (10) provides an emergency supply voltage in emergency operation, It is characterized by: The control component (4) executes a diagnostic routine in which the temporal profile of the capacitor voltage during self-discharge of the capacitor (11) is monitored with respect to whether a predetermined attenuation criterion is met, and the control component (4) triggers a measurement routine in which at least one electrical characteristic variable of the capacitor (11) is determined, depending on whether the attenuation criterion is met.

14. A motor vehicle locking system comprising a drive device (2) with an electric drive motor (3) and a control module (4) according to claim 13 for actuating the drive device (2).

15. The vehicle locking system according to claim 14, characterized in that: A motor vehicle lock (16) is provided for a closing element (5) of the motor vehicle (6), the motor vehicle lock (16) being equipped with a locking pin (17) for maintaining engagement with a locking component and a locking pawl (18) assigned to the locking pin (17), and the electric drive (2) being provided for electrically lifting the locking pawl (18).

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