METHOD FOR OPERATING A MOTOR-DRIVE FLAP ASSEMBLY OF A MOTOR VEHICLE

Description

[0001] The invention relates to a method for operating a motorized flap arrangement of a motor vehicle according to the preamble of claim 1 and to a flap arrangement according to claim 15.

[0002] The motorized adjustment of pivoting tailgates in motor vehicles is an important convenience feature today. It is important for user acceptance that secondary functions such as securely holding the tailgate in intermediate positions are also satisfactorily implemented. Especially with a tailgate pivoting about a horizontal axis, gravity-induced lowering of the tailgate from a de-energized intermediate position regularly occurs if the associated drive arrangement is designed to be reversible. This undesired adjustment movement can be prevented, for example, by a mechanical brake. The known method (DE 10 2012 018 990 A1), on which the invention is based, uses such a mechanical brake. The disadvantage is the high mechanical complexity.

[0003] Furthermore, from US 2019 / 093408 A1 a control arrangement is known which detects a sudden falling of a flap of a motor vehicle, caused for example by the breakage of a drive arrangement, and controls a further electric drive arrangement in such a way that the falling is braked and the flap is closed.

[0004] Furthermore, from DE 10 2011 112 273 A1 a drive arrangement for the motorized adjustment of a flap of a motor vehicle is known, which, upon detection of a non-motorized adjustment of the flap, switches the generator voltage generated in the motor to the supply voltage of the motor vehicle and thus brakes the non-motorized adjustment movement.

[0005] In window regulators, control measures for holding a window pane in intermediate positions are known (DE 10 2004 017 110 A1, EP 1 645 710 A1), which include a control loop aimed at holding the window pane. Such window panes can be part of the flap arrangement in question by being held by the flap and moved accordingly with the flap. Furthermore, the requirements for the motorized adjustment and holding of window panes are fundamentally different from those for freely swinging flaps. On the one hand, the force ratios for adjustment and holding change with each adjustment of the flap.On the other hand, holding a freely swinging flap, which regularly occurs against the weight of the flap, is a trapping-relevant and thus safety-relevant function, the implementation of which represents a challenge in itself in view of the above-mentioned changing force relationships.

[0006] The invention is based on the problem of designing and developing the known method in such a way that the effort for holding the flap in non-energized intermediate positions is reduced.

[0007] The fundamental idea is that when a flap deflection occurs, particularly due to gravity, from a de-energized intermediate position, it is first detected whether a predetermined flap deflection exists that requires holding. If so, a holding control loop is activated, which leads to the corresponding control of the reversible drive assembly.

[0008] The term "intermediate position" is to be understood broadly here and includes any position of the flap in which the flap has been pivoted out of the closed position, i.e., the fully closed position of the flap. In this respect, this term also includes the open position of the flap, i.e., the fully opened position of the flap.

[0009] The term "de-energized intermediate position" means that the damper is in the intermediate position while the actuator assembly is de-energized. The de-energized intermediate position is preferably a static intermediate position in which the damper is stationary.

[0010] The term "reversible drive assembly" means that the drive train of the de-energized drive assembly can be reversed by manually adjusting the flap. A necessary prerequisite for this is the non-self-locking design of the transmission components of the drive train of the drive assembly.

[0011] In detail, it is now proposed that, by means of the control arrangement, a predetermined flap deflection, in particular a gravitational deflection, be detected in a monitoring routine from a de-energized intermediate position of the flap. Upon detection of the predetermined flap deflection, a holding routine is triggered, in which the drive arrangement is controlled by appropriate current supply to a holding flap position in a holding control loop. This thus corresponds to a position control of the flap.

[0012] The proposed solution ensures that the flap is held in intermediate positions without the need for additional mechanical measures. By providing a holding control loop with appropriate feedback, it is possible to react automatically to any environmental conditions, especially a possible slope of the vehicle, etc. The changing force ratios on the flap mentioned above no longer play a significant role.

[0013] In principle, the drive arrangement can comprise a single drive with a drive motor or two drives, each with a drive motor. In the latter case, a variant can be provided for only one of the two drives to be controlled to the holding flap position. This is appropriate if the system friction, which will be explained later, is correspondingly high (claim 2).

[0014] The holding flap position can generally be the intermediate position from which the flap is deflected. This requires that the intermediate position be stored in the control system when it is assumed. Alternatively, however, it can also be provided that the holding flap position is the deflected flap position. This is appropriate, since it will usually be sufficient to maintain the deflected position of the flap (claim 3).

[0015] Preferred variants for the definition of the predetermined flap deflection are the subject of claim 4. Depending on the manner in which the flap deflection is to be detected, a limit value for the flap adjustment path, the flap speed or the flap acceleration may be useful here.

[0016] Claim 5 relates to two preferred variants for detecting the flap deflection, namely monitoring the generator voltage of a drive motor of the drive assembly and monitoring the sensor signal of a sensor associated with the drive assembly. Monitoring the generator voltage is particularly advantageous when no sensor is present to detect flap movement.

[0017] In the particularly preferred embodiment according to claim 6, the manipulated variable of the holding control loop is the electrical voltage and / or the electrical current of at least one drive motor of the drive arrangement. On the one hand, it can be provided that the level of the respective electrical variable is varied depending on the control strategy. On the other hand, a variation of pulse width and pulse frequency can alternatively be provided, provided that the respective electrical variables are pulse-width modulated variables. Regardless of the specific embodiment, the electrical voltage or the electrical current can be used as a manipulated variable in a simple control-technical manner.

[0018] The further preferred embodiments according to claims 7 and 8 relate to the implementation of an operating mode and a standby mode for the control arrangement. While the entire range of functions of the drive arrangement is preferably available in the operating mode, only minimal functions are available in the standby mode. The associated advantage is that power consumption in the standby mode can be kept extremely low. Preferably, the standby mode is set to meet a standby condition.

[0019] An interesting consideration according to claim 7 is that the monitoring routine, but not the holding routine, runs in standby mode. Accordingly, according to claim 8, upon detection of the predetermined flap deflection, the control arrangement is switched to operating mode and the holding routine is triggered. This results in a particularly energy-saving implementation of the proposed solution.

[0020] The likewise preferred embodiments according to claims 9 and 10 relate to the consideration that the magnitude of the restoring force generated by the drive arrangement for holding the flap can be determined and taken into account in the proposed holding control loop. For example, according to claim 10, it is assumed that an exceeding of the restoring force above a predetermined actuation threshold is most likely due to manual action by the user on the flap. Accordingly, one alternative provides that the holding routine is exited in this case. Alternatively or additionally, according to claim 10, an adjustment routine such as a closing adjustment or an opening adjustment is triggered depending on the direction of the restoring force.The holding routine is therefore used in a dual way, namely on the one hand for the original holding of the flap and on the other hand for the detection of any manual force exerted by the user on the flap.

[0021] Another possibility for detecting user actuation is to assign an actuation sensor according to claim 11 to the flap. This further reduces the probability of the user holding the flap in an unwanted manner.

[0022] The further preferred embodiment according to claim 12 relates to the equipment of the drive arrangement with an active side in the form of a motor drive and with a passive side in the form of a spring unit. In particular, if the spring unit is a gas pressure spring, signs of aging are to be expected, which manifest themselves in a reduction in the spring force of the spring unit. This undesired reduction in spring force can be easily detected within the framework of the holding routine, since, depending on the aging state of the spring unit, the motor drive must introduce more or less drive force, usually against gravity, into the flap in order to hold the flap in the holding flap position. Upon detection of a predetermined reduction in the spring force of the spring unit, an error routine is executed, which can be designed differently according to claim 13.This makes it possible to react early to an age-related reduction in the spring force of the spring unit, for example by replacing the spring unit.

[0023] A simple variant for detecting the predetermined reduction arises from claim 14, according to which the manipulated variable is checked accordingly. Preferably, the occurrence of the predetermined reduction in the spring force of the spring unit is detected by checking the manipulated variable in the holding control loop. For this purpose, an error criterion is preferably defined that represents the predetermined reduction in the spring force of the spring unit. This check of the manipulated variable is easy to implement since the holding control loop is already provided for holding the flap.

[0024] According to a further teaching according to claim 15, which also has independent significance, the flap assembly is claimed with the flap adjustable relative to the motor vehicle body, with the drive assembly associated with the flap, and with the control assembly for controlling the drive assembly. In this respect, reference may also be made to all statements relating to the first-mentioned teaching.

[0025] In the particularly preferred embodiment according to claim 16, the flap can be pivoted about a horizontal pivot axis, so that the flap weight preferably acts in the closing direction of the flap. In this case, the system friction according to claim 17 is preferably designed such that the flap is held in at least one non-energized intermediate position by means of the adhesive system friction, whereby, preferably, the sliding system friction that sets in after the adhesive system friction has been overcome is not sufficient to hold the flap. In such a configuration, the flap is therefore designed to be self-holding thanks to the system friction, provided the flap is in a static, i.e. stationary, state. However, as soon as external influences such as a gust of wind, a door slamming, the vehicle being loaded, a loading compartment floor folding over, or the like occur, the flap is held in its original position.If a corresponding mechanical impulse is introduced into the flap, which leads to the aforementioned overcoming of the sticking system friction and the onset of the sliding system friction, an additional measure is required to hold the flap. According to the proposal, the holding control loop is available for this purpose without the need for an additional mechanical brake.

[0026] In the following, the invention is explained in more detail with reference to a drawing which merely represents an exemplary embodiment. In the drawing, Fig. 1 the rear area of ​​a motor vehicle with a proposed flap arrangement, Fig. 2 the drive arrangement of the flap arrangement according to Fig. 1 in a schematic representation and Fig. 3 a proposed method for operating the flap arrangement according to Fig. 1 .

[0027] The proposed method is directed to the operation of a motorized flap assembly 1 of a motor vehicle, wherein the flap assembly 1 has a flap 4 pivotable relative to a motor vehicle body 3. The flap 4 pivots about a pivot axis 4a, the position of which relative to the motor vehicle body 3 can be fixed or variable. Furthermore, the term "flap" is to be understood broadly in this context. It encompasses not only pivotable tailgates, trunk lids, front hoods, and engine hoods, but also pivotable side doors.

[0028] In the illustrated and in this respect preferred embodiment, the flap axis 4a of the flap 4 is aligned substantially horizontally, so that the weight force of the flap 4 acts at least over an adjustment range of the flap 4 in its closing direction.

[0029] The flap assembly 1 has a reversible drive assembly 5 for motorized adjustment of the flap 4. The flap assembly 1 further has a control assembly 6 for controlling the drive assembly 5. The control assembly 6 can be assigned exclusively to the drive assembly 5, which corresponds to a decentralized control concept. In principle, however, it can also be provided that the control assembly 6 is at least partially assigned to a higher-level motor vehicle control system.

[0030] It is now essential that, by means of the control arrangement 6, a predetermined flap deflection, here and preferably due to gravity, is detected in a monitoring routine 7 from a non-energized intermediate position of the flap 4.

[0031] It is also essential that upon detection of the predetermined flap deflection, a holding routine 8 is triggered, in which the drive arrangement 5 is controlled to a holding flap position in a holding control loop. This two-stage procedure via the monitoring routine and the holding routine downstream of the monitoring routine allows, on the one hand, a modular structure in terms of control technology, in which the monitoring routine 7 can be accommodated in a first control module, in particular in a first software module, and the holding routine 8 in a second control module, in particular in a second software module. Furthermore, the monitoring routine 7 can run in a power-saving standby mode, as will be explained below. Finally, the proposed solution leads to a secure holding of the flap 4 in intermediate positions without the need for an additional mechanical brake.

[0032] In the embodiment shown in the drawing, the drive assembly 5 has a first drive 9 and a second drive 10, which engage opposite sides of the flap 4. Here, and preferably, the drives 9, 10 are spindle drives. However, all other types of drives can be used here.

[0033] In principle, it can be provided that both drives 9, 10 are controlled to the holding flap position in the holding routine 8. Here and preferably, however, only one of the two drives 9, 10, here the one in Fig. 2 The actuator 9 shown on the left is used to control the holding flap position. Therefore, reference is always made below to actuator 9. All relevant statements apply accordingly to the other actuator 10.

[0034] Various advantageous variants are conceivable for defining the holding flap position. In a preferred variant, the holding flap position is defined as the intermediate position from which the predetermined flap deflection occurred. For example, it can be provided that the control arrangement 6 continuously stores the flap position, so that in the de-energized intermediate position, a value for the intermediate position is stored in the memory of the control arrangement 6. Based on this, the drive arrangement 5 can then be controlled to the intermediate position in the holding routine.

[0035] However, it may also be advantageous for the flap position to be the deflected flap position. This is advantageous in that no unexpected return movement of flap 4 occurs during the holding routine.

[0036] To prevent accidental triggering of the hold routine, the predetermined flap deflection that triggers the hold routine must be defined appropriately. Preferably, the predetermined flap deflection is a deflection of the flap 4 from the respective intermediate position by a predetermined minimum flap adjustment travel. Alternatively or additionally, the predetermined flap deflection can also be defined by a minimum flap speed and / or a minimum flap acceleration.

[0037] To detect the predetermined flap deflection, the generator voltage of a drive motor 9a of the drive arrangement 5, which results from the reversing of the drive train of the drive arrangement 5, can advantageously be used. The generator voltage can also be used, in principle, to supply at least part of the control arrangement 6 with an electrical voltage until the control arrangement 6 has been awakened in a manner to be explained below.

[0038] Alternatively or additionally, it may be provided that the sensor signal of a sensor 11 assigned to the drive arrangement 1 is monitored in the monitoring routine for detecting the predetermined flap deflection.

[0039] The holding control loop is a control loop with a feedback loop, which can in principle also be cascaded. The reference variable of the holding control loop is preferably the holding flap position, while the manipulated variable of the holding control loop is preferably the electrical voltage and / or the electrical current of at least one drive motor 9a of the drive arrangement 1. The control-related details of such a control loop as such are known from the prior art.

[0040] The control arrangement 6 preferably has a driver unit for supplying electrical drive power to the drive arrangement 5. Conventional bridge circuits, in particular H-bridge circuits, can be used here, for example. Furthermore, the control arrangement 6 is equipped with a logic unit for controlling the driver unit. The logic unit can, in principle, also serve other purposes. For example, the logic unit can verify the operator's authentication when opening the flap 4.

[0041] For the purpose of energy-saving operation, it is preferably provided that the control arrangement 6 is switched from an operating mode to a standby mode when the flap 4 is in an intermediate position and a standby condition is met. The standby mode is defined here and preferably such that the monitoring routine 7 runs, but not the holding routine 8. In a particularly preferred embodiment, all power-consuming functions of the control arrangement 6 are deactivated in the standby mode unless they are required to wake the control arrangement 6 from the standby mode.

[0042] The standby condition here is preferably the expiration of a predetermined standby period without motor control of the drive arrangement 5. Other variants for defining the standby condition are conceivable.

[0043] Preferably, the control arrangement 6 is brought into the operating mode upon detection of the predetermined flap deflection, which is preferably followed by the triggering of the holding routine 8. This is shown in the illustration according to Fig. 3 can be found.

[0044] Within the Fig. 3 In the schematically illustrated monitoring routine 7, a monitoring step 12 first takes place in which it is checked whether any flap deflection has occurred at all. This can be done, for example, based on the sensor signal from sensor 11. In comparison step 13, it is checked whether the detected flap deflection meets the criteria for a predetermined flap deflection. If this is not the case, a jump is made back to monitoring step 12. If the detected flap deflection meets the criteria for the predetermined flap deflection, the wake-up step 14 is triggered, which involves transferring the control arrangement 6 from standby mode to operating mode.

[0045] Subsequently, the Fig. 3 The holding routine 8 shown is triggered, in which the control 15 is triggered for the holding flap position. During the control process, a value for the restoring force generated by the drive arrangement 5 is preferably determined. To ensure that no excessive, pinching-relevant forces are applied, the holding control loop is preferably designed such that the value of the restoring force is limited to a predetermined restoring force limit value.

[0046] Various advantageous variants are conceivable for determining the restoring force. Preferably, the respective restoring force is determined from the electrical voltage and / or the electrical current of at least one drive motor 9a of the drive arrangement 5 based on an electrical drive model of the respective drive motor 9a. In principle, the values ​​for voltage and / or current can correspond to the above-mentioned manipulated variable or be derived from it.

[0047] The particular advantage of determining a value for the restoring force is that it allows a user request to adjust the flap 4 to be detected, which is expressed in a user-side force applied to the flap 4. For this purpose, the restoring force is checked by the control arrangement 6 in a comparison step 16 to determine whether the restoring force exceeds a predetermined actuation threshold. If the actuation threshold is exceeded by the restoring force, the holding routine 8 is exited in a preferred alternative. This first ensures that the control arrangement 6, with the holding routine 8, does not work against the user.

[0048] Alternatively or additionally, an adjustment routine 18 can be triggered, as shown in the illustration Fig. 3 can be seen. In the adjustment routine 18, a motorized adjustment of the flap 4, in particular a motorized closing adjustment into the closed position of the flap 4 or a motorized opening adjustment into the open position of the flap 4, is preferably effected in an adjustment direction opposite to the restoring force. If the user therefore presses the flap 4 in the closing direction, a restoring force is initially generated in the holding routine 8, which counteracts the force applied by the user. If the restoring force exceeds the actuation threshold, the control arrangement 6 follows the user's request by appropriately controlling the drive arrangement 5 by motorized adjustment of the flap 4 in the closing direction.

[0049] Alternatively or additionally, it is conceivable for the user to express a desire to adjust the flap 4 in another way. This can be done, for example, by operating a radio remote control. For this purpose, the comparison step 16 is followed by a further query step 17 aimed at querying a possible user request, which in turn can trigger the adjustment routine 18.

[0050] To further prevent the holding routine 8 from working against the user's wishes, as mentioned above, the flap 4 is assigned an actuation sensor 19 for detecting a user actuation. In this context, it is provided that upon detection of a user actuation, the holding routine 8 is exited and / or an adjustment routine 18 explained above is triggered. Here and preferably, the actuation sensor 19 is a proximity sensor for detecting a user movement. Alternatively, the actuation sensor 19 can be a force sensor for detecting a user force acting on the flap 4, in particular a hand force impressed into the flap 4 by the user.

[0051] The transfer of the control arrangement 6 back to standby mode can be provided in different ways. Fig. 3 This is provided, for example, as indicated by the reference number 20, after completion of the adjustment routine 18.

[0052] It was already mentioned above that the drive arrangement 5 can have one motor drive 9, 10 or two motor drives 9, 10. In a further, preferred variant, the drive arrangement 5 has a drive 9 for the motorized adjustment of the flap 4, and the drive arrangement 5 has a spring unit, in particular a gas pressure spring unit, designed separately from the drive 9 to introduce a spring force into the flap 4. The spring unit preferably serves to support the motor drive 9 against gravity.

[0053] As also mentioned above, the spring unit is subject to aging behavior, particularly if the spring unit is a gas pressure spring unit. This aging behavior is preferably detected by means of the control arrangement 6. In detail, it is preferably the case that a predetermined, particularly aging-related, reduction in the spring force of the spring unit, in particular a reduction in the spring force of the spring unit below a limit spring force, is detected by means of the control arrangement 6 in the holding routine and an error routine is then carried out. The limit spring force is further preferably dependent on the flap position and / or the compression travel of the spring unit.

[0054] Numerous advantageous variants are conceivable for the design of the error routine. In a first preferred variant, a warning message regarding the aging state of the spring unit is issued via a display device in the error routine. Alternatively or additionally, it is provided that an error memory regarding the aging state of the spring unit is set in the error routine.

[0055] Since the reduction in the spring force of the spring unit cannot be easily detected directly, an indirect approach is preferred for this purpose, in which the above-mentioned manipulated variable of the holding control loop is checked. Preferably, by means of the control arrangement 6 in the holding routine for detecting the predetermined reduction in the spring force of the spring unit, the manipulated variable in the holding control loop is checked for fulfillment of an error criterion. The error criterion is preferably defined by the manipulated variable or a time-averaged value of the manipulated variable exceeding a limit manipulated variable. The limit manipulated variable further preferably depends on the flap position and / or on the slope of the motor vehicle 2 and / or on an ambient temperature of the motor vehicle 2. These dependencies can be easily determined in tests and stored in a memory of the control arrangement 6.The age of the spring unit can also be taken into account, for example to avoid a slowly aging but still sufficiently functional spring unit leading to the setting of the above error memory.

[0056] It has already been pointed out that the control arrangement 6 preferably has software that maps the proposed method.

[0057] According to a further teaching, which also has independent significance, the flap assembly 1 designed to carry out the proposed method is claimed as such. The flap assembly 1 accordingly has a flap 4 that is adjustable relative to the motor vehicle body 3. Furthermore, the flap assembly 1 is equipped with a drive assembly 5 associated with the flap 4 and a control assembly 6.

[0058] In the Fig. 1In the illustrated and thus preferred embodiment, the flap 4 is pivotable about a horizontal pivot axis 4a, which, as mentioned above, can be arranged rigidly or adjustably relative to the motor vehicle body 3. Accordingly, the gravitational force urges the flap 4 in the closing direction, as has also already been explained.

[0059] The system friction, i.e. the friction that must be overcome to adjust the flap 4, is designed such that, at least in the normal state, and preferably always, the flap 4 is held in at least one de-energized intermediate position, preferably in all intermediate positions, by means of the adhesive system friction. In a particularly preferred embodiment, however, the sliding system friction that sets in after the adhesive system friction has been overcome is not sufficient to hold the flap 4, in particular against the weight of the flap 4. This is the point in time at which the holding routine 8 is triggered upon detection of the predetermined flap deflection. As mentioned, the flap 4 is held purely by control technology, without the need for a mechanical brake.

[0060] The normal state is defined here and preferably such that the motor vehicle 2 is on a slope corresponding to a road gradient within + / -40%, preferably + / -30%. Outside of the normal state, i.e., on an exceptionally steep slope, it may be that the flap 4 is held in any position purely by control technology, since the static friction may not be sufficient to hold the flap 4.

Claims

1. Method for the operation of a motorized flap arrangement (1) of a motor vehicle (2), wherein the flap arrangement (1) has a flap (4) which is pivotable relative to a car body (3), wherein the flap arrangement (1) has a reversible drive arrangement (5) for motorized adjustment of the flap (4) and a control arrangement (6) for controlling the drive arrangement (5), wherein a predetermined flap deflection, in particular caused by gravity, from a deenergized intermediate position of the flap (4) is detected by means of the control arrangement (6) in a monitoring routine (7) and on detection of the predetermined flap deflection a holding routine (8) is triggered, in which the drive arrangement (5) is controlled to a holding flap position in a holding control circuit.

2. Method according to Claim 1, characterized in that the drive arrangement (5) has two drives (9, 10) for motorized adjustment of the flap (4), and in that in the holding routine both drives (9, 10) are controlled to the holding flap position, or in that only one of the two drives (9, 10) is controlled to the holding flap position.

3. Method according to Claim 1 or 2, characterized in that the holding flap position is the intermediate position, or in that the holding flap position is the deflected flap position.

4. Method according to any one of the preceding claims, characterized in that the predetermined flap deflection is a deflection of the flap (4) from the intermediate position by a predetermined minimum flap adjustment distance and / or with a minimum flap speed and / or with a minimum flap acceleration.

5. Method according to any one of the preceding claims, characterized in that in the monitoring routine (7) the generator voltage of a drive motor (9a) of the drive arrangement (5) and / or the sensor signal of a sensor (11) associated with the drive arrangement (5) is monitored for the detection of the predetermined flap deflection.

6. Method according to any one of the preceding claims, characterized in that the control variable of the holding control circuit is the holding flap position, and the controlled variable of the holding control circuit is the electric voltage and / or the electric current of at least one drive motor (9a) of the drive arrangement (5).

7. Method according to any one of the preceding claims, characterized in that with the flap (4) in an intermediate position the control arrangement (6) is brought from an operating mode into a standby mode to fulfil a standby condition in which the monitoring routine (7) runs, but not the holding routine (8), preferably in that the standby condition takes place during a predetermined standby period without motorized control of the drive arrangement (5).

8. Method according to Claim 7, characterized in that the control arrangement (6) is brought into the operating mode for detection of the predetermined flap deflection and the holding routine (8) is triggered.

9. Method according to any one of the preceding claims, characterized in that in the holding routine (8) a value for the restoring force generated by the drive arrangement (5) is determined, preferably in that the holding control circuit is designed so that the value of the restoring force is limited to a predetermined restoring force limit.

10. Method according to Claim 9, characterized in that the restoring force is then checked by means of the control arrangement (6) to determine whether a predetermined actuation threshold is exceeded and in that when the actuation threshold is exceeded the holding routine (8) is exited and / or an adjustment routine (18) is triggered, in which a motorized adjustment of the flap (4), in particular a motorized closing adjustment to the closing position of the flap (4) or a motor opening adjustment to the opening position of the flap (4), is effected in an adjustment direction opposite to the restoring force.

11. Method according to any one of the preceding claims, characterized in that the flap (4) is associated with an actuation sensor (19) for the detection of a user actuation and in that on detection of a user actuation the holding routine (8) is exited and / or an adjustment routine (18) is triggered, in which a motorized adjustment of the flap (4) is effected, in particular a motorized closing adjustment or a motorized opening adjustment, preferably in that the actuation sensor (19) is a proximity sensor for detecting a user movement or a force sensor for detecting a user force action.

12. Method according to any one of the preceding claims, characterized in that the drive arrangement (5) for motorized adjustment of the flap (4) has a drive (9) and in that the drive arrangement (5) has a deflecting spring unit, in particular a gas pressure spring unit, which is designed separately from the drive (9), for initiating a spring force into the flap (4), in particular acting against gravity, and in that a predetermined, in particular ageing-related, reduction of the spring force of the spring unit, in particular a reduction of the spring force of the spring unit to below a spring force limit, is detected by means of the control arrangement (6) in the holding routine, and thereupon an error routine is carried out.

13. Method according to any one of the preceding claims, characterized in that a warning message with respect to the ageing state of the spring unit is issued via a display device in the error routine, and / or in that in the error routine an error memory is set with respect to the ageing state of the spring unit.

14. Method according to any one of the preceding claims, characterized in that in the holding routine for detecting the predetermined reduction of the spring force of the spring unit the controlled variable in the holding control circuit is checked by means of the control arrangement (6) for the fulfilment of an error criterion, preferably in that the error criterion is defined such that the controlled variable or a time average of the controlled variable exceeds a controlled variable limit, preferably in that the controlled variable limit depends on the flap position and / or on an inclined position of the motor vehicle (2) and / or on an ambient temperature of the motor vehicle (2).

15. Flap arrangement, wherein the flap arrangement (1) has a flap (4) which is pivotable relative to a car body (3), wherein the flap arrangement (1) has a reversible drive arrangement (5) for motorized adjustment of the flap (4) and a control arrangement (6) for controlling the drive arrangement (5), wherein the control arrangement (6) detects a predetermined flap deflection, in particular caused by gravity, from a deenergized intermediate position of the flap (4) in a monitoring routine (7) and on detection of the predetermined flap deflection the control arrangement (6) triggers a holding routine (8), in which the control arrangement (6) controls the drive arrangement (5) to a holding flap position in a holding control circuit.

16. Flap arrangement according to Claim 15, characterized in that the flap (4) is pivotable around a horizontal pivot axis (4a).

17. Flap arrangement according to Claim 15 or 16, characterized in that the system friction is designed so that the flap (4) is held by means of the adhesive system friction in at least one deenergized intermediate position, preferably in that the sliding system friction, which starts after overcoming the adhesive system friction, is not however sufficient for holding the flap (4).