Method for controlling a drive arrangement for a flap of a motor vehicle, control arrangement, drive arrangement and flap arrangement

Abstract

Method for controlling a drive arrangement (1) for a flap (2) of a motor vehicle (3) by means of a control arrangement (4), wherein the drive arrangement (1) has a first electric drive (5) and a second electric drive (6), each of which is coupled to the flap (2) in terms of drive technology, wherein current values ​​(i1, i2) occurring during the motorized adjustment of the flap (2) are determined for the drives (5, 6) in a determination routine, wherein in an anti-pinch routine the determined current values ​​(i1, i2) of the two drives (5, 6) are monitored for the occurrence of at least one predetermined pinch criterion representing a pinch case and wherein, upon occurrence of a pinch criterion, a pinch case routine is executed, characterized by that a pinching criterion is defined by the fact that a predetermined relation of the current value (i1) of the first drive (5) to the current value (i2) of the second drive (6) exceeds or falls below a pinching threshold.

Description

[0001] The invention relates to a method for controlling a drive arrangement for a flap of a motor vehicle according to the preamble of claim 1, a control arrangement for carrying out such a method according to claim 10, a drive arrangement with such a control arrangement according to claim 11 and a flap arrangement with such a drive arrangement according to claim 12.

[0002] Motorized adjustment of flaps is of particular importance in the context of increasing comfort in motor vehicles. Such a flap could be, for example, a tailgate, trunk lid, hood, or similar.

[0003] Due to the ever-increasing weight of flaps, it is known to equip the drive arrangement in question with two electric drives, which, for example, act on opposite edges of the flap.

[0004] The motorized adjustment of a flap inherently carries a risk of jamming. This applies particularly to a motorized closing movement of the flap, during which the flap opening continuously decreases until the flap seal is compressed.

[0005] In the known method (DE 10 2016 209 915 A1), from which the invention is based, an anti-pinch routine is provided in which the current values ​​of two drives are compared with limit values, with different limit values ​​being assigned to the two drives. Exceeding one of the limit values ​​triggers an anti-pinch routine in which both drives are switched off.

[0006] A challenge with the known method is providing a consistently high level of detection reliability in the event of an entrapment across the entire adjustment range of the flap. For example, it will be necessary to adjust the limit values ​​assigned to both drives according to the flap position, but also according to external boundary conditions such as a slope or similar. This often results in an unintended reduction in the sensitivity of the entrapment protection, thus limiting the overall operational reliability of the drive assembly. This adaptation of the entrapment protection routine to the prevailing conditions is addressed, for example, in EP 1 860 265 B1. Furthermore, US 2016 / 0 222 713 A1 discloses a method for controlling an electric tailgate by synchronizing a left spindle drive and a right spindle drive.

[0007] The invention is based on the problem of designing and further developing the known method in such a way that the operational safety of the drive arrangement is increased, particularly with regard to the function of the pinch protection, using simple means.

[0008] The above problem is solved in a method according to the preamble of claim 1 by the features of the characterizing part of claim 1.

[0009] First, it is assumed that the drive arrangement comprises a first electric drive and a second electric drive, each coupled to the flap. A determination routine is provided in which the current values ​​for the drives occurring during the motorized adjustment of the flap are determined.

[0010] Furthermore, it is assumed that an anti-pinch routine is provided, in which the determined current values ​​of the two drives are monitored for the occurrence of at least one predetermined pinch criterion representing a pinch case, and in which, if a pinch criterion occurs, a pinch case routine is executed, in which, for example, the two drives are switched off.

[0011] As proposed, it has now been recognized that a jamming event caused by an obstruction in the valve opening usually acts on the valve asymmetrically. This means that the obstruction rarely acts on the valve in a central area, but rather that this effect on the valve usually occurs laterally. This, in turn, means that with at least slight compliance of the valve, the actuator closer to the obstruction is initially "braked" more strongly by the obstruction than the other actuator.

[0012] In a broader sense, the term "flexibility" here encompasses not only elastic deformation of the flap itself, but also any play or similar between the actuators and the flap.

[0013] The proposed solution is based on the resulting finding that the above asymmetrical jamming case can easily be detected by recording a deviation in the drive behavior of the two drives relative to each other.

[0014] Specifically, it is proposed that a jamming criterion is defined by the fact that a predetermined ratio of the current value of the first drive to the current value of the second drive exceeds or falls below a jamming threshold.

[0015] A particularly advantageous aspect of the proposed solution is that the detection of a jamming event is now completely independent of prevailing conditions such as flap position, slope angle, etc., since all these conditions affect both drives equally. This results in an overall increase in operational reliability for the entire drive system.

[0016] Furthermore, the proposed solution is easy to implement, possibly even without the need for additional measurement measures. This is because the current values ​​mentioned above for controlling the drives are often generated within the control system itself and can therefore be used without further effort as part of the anti-pinch routine.

[0017] The current value can, in principle, correspond to the magnitude of the current flowing through the drive. However, it can also be provided that the current value corresponds to the time derivative of the magnitude of the current flowing through the drive. This depends, in principle, on the signals available for the current flowing through the drive (claim 2).

[0018] The further preferred embodiments according to claims 3 and 4 relate to possibilities for defining the predetermined relationship between the current value of the first drive and the current value of the second drive. In the simplest case, the predetermined relationship is a difference (claim 3) or a ratio (claim 4). Other ways of defining the predetermined relationship are conceivable.

[0019] The preferred embodiments according to claims 5 to 8 relate to advantageous variants for implementing the entrapment scenario routine. In the simplest case according to claim 5, the drives are braked and / or stopped and / or reversed. In the further preferred embodiment according to claim 8, the two drives are controlled differently in the entrapment scenario routine depending on which drive is responsible for the entrapment scenario. For example, it may be provided that the drive not responsible for the entrapment scenario is reversed at a higher speed than the other drive in order to restore synchronous operation between the two drives as quickly as possible.

[0020] As mentioned above, the proposed solution addresses an asymmetrical pinching scenario, which affects the two drives differently. Accordingly, in the further preferred embodiment according to claim 9, an additional pinching criterion is defined, which also allows for the reliable detection of a symmetrical pinching scenario. All variants defined in claim 9 involve checking the current values ​​of the two drives, either individually or as a sum, with regard to whether a pinching threshold has been exceeded. The combination of the proposed detection of an asymmetrical pinching scenario with the detection of a symmetrical pinching scenario based on the additional pinching criterion results in a particularly high overall operational reliability for the drive arrangement.

[0021] According to a further teaching as claimed in claim 10, which has independent significance, the control arrangement is designed to carry out the proposed procedure as claimed. Reference may be made to all explanations concerning the proposed procedure.

[0022] According to a further teaching as claimed in claim 11, which also has independent significance, a drive arrangement for a flap of a motor vehicle is claimed, comprising a first drive and a second drive, which in the assembled state are each coupled to the flap via a drive mechanism, and a proposed control arrangement as such. Reference may also be made in this respect to all descriptions of the proposed method.

[0023] According to a further teaching, as per claim 12, which also has independent significance, a flap arrangement of a motor vehicle is claimed as such, comprising a flap and a proposed drive arrangement associated with the flap. Reference may also be made in this respect to all descriptions of the proposed method.

[0024] In the particularly preferred embodiment according to claim 13, the flap is adjustable about a horizontal flap axis, as is usually the case with tailgates and trunk lids. The interesting aspect here is that the two actuators are coupled to the flap on horizontally opposite sides. A lateral jamming scenario, which, as mentioned above, acts asymmetrically on the two actuators, can be particularly well addressed with the proposed solution. This applies especially according to claim 14 if the flap is designed to be elastically deformable.

[0025] The invention will now be explained in more detail with reference to a drawing that illustrates only one embodiment. The drawing shows Fig. 1. the rear area of ​​a motor vehicle with a flap arrangement for carrying out the proposed procedure, Fig. 2 the drive arrangement and the control arrangement of the flap arrangement according to Fig. 1 in a schematic representation, Fig. 3. The electric current flowing through each of the two drives a) during a jam-free closing movement of the flap and b) during a jamming closing movement of the flap and Fig. 4 the time derivative of the currents flowing through the drives a) for the situation according to Fig. 3a) and b) for the situation according to Fig. 3b).

[0026] The proposed method serves to control a drive arrangement 1 for a flap 2 of a motor vehicle 3 by means of a control arrangement 4.

[0027] The term "flap" in this context includes a tailgate, a rear lid, a front hood, in particular a motor hood, a motor vehicle door, in particular a side or rear door, or the like.

[0028] In the illustrated and thus preferred embodiment, the flap 2 is designed to pivot about a flap axis 2a. Furthermore, preferably, the flap axis 2a is oriented substantially horizontally, so that the weight force of the flap 2 acts in its closing direction, at least over an adjustment range of the flap 2.

[0029] The control arrangement 4 can be configured as a flap control unit assigned to flap 2, which interacts with a higher-level vehicle control system. Alternatively, instead of this decentralized approach, the control arrangement 4 can also be part of a central vehicle control system.

[0030] The drive arrangement 1 comprises a first electric drive 5 and a second electric drive 6, each of which is coupled to the flap 2. Both drives 5, 6 are spindle drives with a motor unit 5a, 6a and a downstream spindle-spindle nut gearbox 5b, 6b. An exemplary arrangement of such drives 5, 6 is shown in DE 10 2008 057 014 A1, which originates from the applicant and whose content is hereby incorporated into the present application.

[0031] In a diagnostic routine, the current values ​​i1, i2 occurring during the motorized adjustment of flap 2 are determined for the actuators 5, 6. The current values ​​i1, i2 relate to the electrical currents I1, I2 flowing through the actuators 5, 6, in particular through the motor units 5a, 6a, as will be explained later. The current values ​​i1, i2 thus represent, in general terms, the driving forces applied by the actuators 5, 6, so that a jamming scenario, which would be caused by a Fig. 1 only exemplary depicted entrapment obstacle 7 results, based on the current values ​​i1, i2 of the drives 5, 6 can be recorded.

[0032] Accordingly, an anti-pinch routine is provided in which the determined current values ​​i1, i2 of the two drives 5, 6 are monitored for the occurrence of a predetermined pinch criterion representing a pinch case.

[0033] As soon as a predetermined jamming criterion is met, a jamming event is considered detected in the control arrangement 4. As proposed, a jamming event routine is executed when a jamming criterion is met. In the jamming event routine, the two drives 5 and 6 are controlled in such a way that the jamming event is resolved. In the simplest case, both drives 5 and 6 are reversed for this purpose, as will be explained later.

[0034] Crucially, a pinching criterion is defined by whether a predetermined ratio of the current value i1 of the first drive 5 to the current value i2 of the second drive 6 exceeds or falls below a pinching threshold S. The term "pinching threshold" is to be interpreted broadly here. It encompasses the definition of a permissible range for the predetermined ratio of the current values ​​i1 and i2, whereby a deviation from this permissible range is interpreted by the control arrangement 4 as the detection of a pinching event. Therefore, the term "pinching threshold" does not necessarily refer to a single limit value. Furthermore, it should be noted that the pinching threshold S can assume different value ranges depending on the operating mode of the drive arrangement 1.

[0035] For the sake of completeness, it should be noted that the control of the drive arrangement 1 can also include the acquisition and processing of drive speeds or similar data. For example, at least one drive can be assigned a rotary encoder to determine such speed values. It is also conceivable that speed values ​​are estimated based on the current or voltage values ​​assigned to drives 5 and 6. The same applies to the possible determination of drive or flap positions. While none of this is excluded by the proposed solution, it is only marginally relevant to explaining the proposed solution.

[0036] Fig. Figure 3 shows the electrical currents I1, I2 flowing through the drives 5, 6, which are determined during jam-free operation according to Fig. 3a) essentially the same.

[0037] Fig. Figure 4a) shows the time derivatives I'1, I'2 of the currents I1, I2 flowing through the drives 5, 6. The time derivatives I'1, I'2 are essentially identical to each other, which is evident from the representation according to Fig. 3a) is also appropriate.

[0038] Fig. 3b) now shows the occurrence of an asymmetrical crushing case mentioned above, which in Fig. 1 is indicated by the anti-pinch device 7 arranged laterally in the flap opening 2b. With at least slight compliance of the flap 2, the anti-pinch device 7 acts primarily as a brake on the first drive 5, and less so as a brake on the second drive 6, at least upon initial contact between the flap 2 and the anti-pinch device 7.

[0039] In a motion control system implemented here, and preferably by the control arrangement 4, the motion control loop will ensure an increased current supply to the first drive 5 in order to guarantee synchronous operation of both drives 5, 6. This is in Fig. 3b) shown. From the representation according to Fig. 3b) It follows that the currents I1, I2 flowing through the actuators 5, 6 diverge significantly after the flap 2 first makes contact with the anti-pinch device 7. The proposed control arrangement 4 detects the pinching event based on this.

[0040] The respective current values ​​i1, i2 underlying the anti-pinch routine can, in principle, correspond to the magnitude of the current flowing through the respective drive 5, 6. Alternatively, it can be provided that the respective current values ​​i1, i2 correspond to the time derivative I'1, I'2 of the magnitude of the current flowing through the respective drive 5, 6, which is assumed in the following explanations. All related explanations apply accordingly to the first-mentioned alternative.

[0041] To filter out manufacturing tolerances and all static influencing factors during the execution of the proposed anti-pinch routine, it is preferably provided that the determined currents I1, I2 flowing through the drives 5, 6 and / or the time derivatives I'1, I'2 are subjected to high-pass filtering. This is in Fig. 4 at least for the derivatives I'1, I'2.

[0042] Several advantageous variants are conceivable for defining the predetermined relationship. In a preferred variant, which is particularly easy to implement from a control engineering perspective, the predetermined relationship is the difference between the current value i1 for the first drive 5 and the current value i2 for the second drive 6.

[0043] Alternatively, it can be provided that the predetermined relation is the ratio between the current value i1 for the first drive 5 and the current value i2 for the second drive 6.

[0044] In principle, the predetermined relationship can be any rule that describes the two current values ​​i1, i2 relative to each other. This includes, for example, the correlation functions known from telecommunications engineering.

[0045] In the following, it is assumed that the predetermined relationship is the difference between the current value i1 for the first drive 5 and the current value i2 for the second drive 6. All related explanations apply accordingly to all other variants of the predetermined relationship. The difference between the two current values ​​i1, i2 is in Fig. 4b) indicated by the reference symbol “Δi”.

[0046] In the entrapment scenario routine, measures are generally taken to resolve the entrapment situation. Preferably, the control arrangement 4 is used to brake, stop, and / or reverse the drives 5 and 6 in the entrapment scenario routine. In a particularly preferred embodiment, these measures apply identically to both drives 5 and 6.

[0047] Given that the pinching scenario to be addressed by the proposed solution is preferably an asymmetrical pinching scenario as described above, the drives 5, 6 are preferably controlled differently in the pinching scenario routine. For this purpose, the pinching scenario routine determines, based on an assignment criterion, which of the two drives 5, 6 the pinching scenario is to be assigned to. The assignment of the pinching scenario to one of the two drives 5, 6 depends on which drive 5, 6 is affected more by the pinching scenario than the other. In the illustrated and thus preferred embodiment, the first drive 5 is braked more strongly by the pinching obstacle 7 when the first contact occurs between the flap 2 and the pinching obstacle 7 than the second drive 6, so that the pinching scenario is to be assigned to the first drive 5 in the sense described above.

[0048] Consequently, it is preferably provided that the assignment criterion is defined by assigning the entrapment case to the drive 5, 6 with the higher current value i1, i2 in the entrapment case routine. According to Fig. 4 This is obviously the first drive 5.

[0049] After determining, based on the above allocation criterion, which drive 5, 6 is responsible for the jamming situation, in a further preferred embodiment this drive 5, 6 is controlled differently than the other drive 6, 5. In the illustrated and thus preferred embodiment, it is conceivable, for example, that the second drive 6 is reversed faster than the first drive 5 in order to prevent jamming of the two drives 5, 6 and to ensure the most synchronous operation possible of both drives 5, 6.

[0050] It has already been pointed out that, in addition to the proposed detection of an asymmetrical pinching event, a further method for detecting a pinching event, particularly a symmetrical one, can be applied. Accordingly, a further pinching criterion is preferably defined by the fact that the current value i1 of the first actuator 5 exceeds a pinching threshold and / or the current value i2 of the second actuator 6 exceeds a pinching threshold and / or the sum of both current values ​​i1, i2 exceeds a pinching threshold. Alternatively or additionally, a further pinching criterion can be defined by the fact that the deviation of the adjustment speed of the flap 2 from a target adjustment speed of the flap 2 exceeds a pinching threshold. All of the above-mentioned pinching thresholds are, of course, different for the respective pinching criterion.

[0051] The combination of the proposed detection of an asymmetrical pinching event with the latter preferred variants for the detection of a, in particular, symmetrical pinching event results in a very high operational reliability of the drive arrangement, especially with regard to pinching protection.

[0052] According to a further doctrine, which has independent significance, the tax order 4, which is established for carrying out the proposed procedure, is claimed as such. The essential point here is the fact that tax order 4 is established to implement the investigation routine and the anti-pinch routine. Reference may be made to all related explanations concerning the proposed procedure.

[0053] According to a further teaching, which is also of independent significance, the drive arrangement 1 is claimed as such, comprising the first drive 5 and the second drive 6, which in the assembled state are each coupled to the flap 2 via a drive mechanism, and with the above control arrangement 4. Reference may also be made in this respect to all explanations of the proposed method.

[0054] According to a further teaching, which is also of independent significance, a flap arrangement of a motor vehicle with a flap 2 and a proposed drive arrangement 1 associated with the flap 2 is claimed as such. Reference may also be made in this respect to all related explanations of the proposed method.

[0055] With regard to the proposed flap arrangement, reference should also be made to the preferred position of the flap axis 2a, which, as mentioned above, is horizontally oriented in a particularly preferred embodiment, with the two actuators 5, 6 being coupled to the flap 2 on horizontally opposite sides. As mentioned above, the flap 2 preferably provides a certain degree of deformability, such that a one-sided jamming event leads to at least a slight deformation of the flap 2. This allows the proposed solution to be implemented in a particularly effective manner.

Claims

[1] Method for controlling a drive arrangement (1) for a flap (2) of a motor vehicle (3) by means of a control arrangement (4), wherein the drive arrangement (1) has a first electric drive (5) and a second electric drive (6), each of which is coupled to the flap (2) in terms of drive technology, wherein current values ​​(i1, i2) occurring during the motorized adjustment of the flap (2) are determined for the drives (5, 6) in a determination routine, wherein in an anti-pinch routine the determined current values ​​(i1, i2) of the two drives (5, 6) are monitored for the occurrence of at least one predetermined pinch criterion representing a pinch case and wherein, upon occurrence of a pinch criterion, a pinch case routine is executed, characterized by , that a pinching criterion is defined by the fact that a predetermined relation of the current value (i1) of the first drive (5) to the current value (i2) of the second drive (6) exceeds or falls below a pinching threshold. [2] Method according to claim 1, characterized by , that the respective current value (i1, i2) corresponds to the magnitude of the current flowing through the respective drive, or that the respective current value (i1, i2) corresponds to the time derivative (I'1, I'2) of the magnitude of the current flowing through the respective drive (I'1, I'2). [3] Method according to claim 1 or 2, characterized by , that the predetermined relation is a difference between the current value (i1) for the first drive (5) and the current value (i2) for the second drive (6). [4] Method according to claim 1 or 2, characterized by , that the predetermined relation is the ratio between the current value (i1) for the first drive (5) and the current value (i2) for the second drive (6). [5] Method according to any one of the preceding claims, characterized by , that in the entrapment routine the drives (5, 6) are braked and / or stopped and / or reversed by means of the control arrangement (4). [6] Method according to any one of the preceding claims, characterized by , that in the entrapment case routine, based on an assignment criterion, it is determined which of the two drives (5, 6) the entrapment case is to be assigned. [7] Method according to claim 6, characterized by , that the assignment criterion is defined by the fact that the drive (5, 6) with the higher current value (i1, i2) in the entrapment case routine is to be assigned the entrapment case. [8] Method according to claim 7, characterized by , that in the entrapment case routine the drive (5, 6), to which the entrapment case is to be assigned according to the assignment routine, is controlled differently than the other drive (5, 6). [9] Method according to any one of the preceding claims, characterized by , that a further clamping criterion is defined by the fact that the current value (i1) of the first drive (5) exceeds a clamping threshold and / or the current value (i2) of the second drive (6) exceeds a clamping threshold and / or the sum of the current values ​​(i1, i2) of both drives (5, 6) exceeds a clamping threshold, and / or that a further clamping criterion is defined by the fact that the deviation of the adjustment speed of the flap (2) from a target adjustment speed of the flap (2) exceeds a clamping threshold. [10] Tax arrangement established to carry out a procedure according to any of the preceding claims. [11] Drive arrangement for a flap (2) of a motor vehicle (3) with two drives (5, 6) which are coupled to the flap (2) in the assembled state and with a control arrangement (4) according to claim 10. [12] Flap arrangement of a motor vehicle (3) with a flap (2) and a drive arrangement (1) associated with the flap (2) according to claim 11. [13] Valve arrangement according to claim 12, characterized by , that the flap (2) is adjustable about a horizontal flap axis (2a) and that the two drives (5, 6) are coupled to the flap (2) on horizontally opposite sides of the flap (2) in a drive-related manner. [14] Valve arrangement according to claim 12 or 13, characterized by , that the flap (2) is designed to be elastically deformable in such a way that a one-sided jamming event leads to at least a slight deformation of the flap (2).

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