Detecting and preventing a clamping event

Abstract

The invention relates to a device (1) for detecting a clamping event of a motor-actuatable closing system of a vehicle (2), comprising a sensor electrode (3) and a reference sensor electrode (15) which at least partly surrounds the edge of a vehicle (2) opening (O) that can be closed by means of at least one closure element (4). A control unit (5) is provided which is designed to - apply an electric potential to the sensor electrode (3) for a charging process and a ground potential (GND) to the reference sensor electrode (15) for a discharging process, - detect a period of time until reaching a minimum threshold for the electric potential for the sensor electrode (3) and the reference sensor electrode (15), said minimum threshold being produced by the back flow of charges across the ground potential (GND), - ascertain the difference between the period of time detected for the sensor electrode (3) and the period of time detected for the reference sensor electrode (15), and - if the difference exceeds a specified threshold and if the period of time detected for the sensor electrode (3) deviates from a specified normal period of time or a normal period of time detected in a state which has been detected without an immediately imminent clamping event, an immediately imminent clamping event is inferred.

Description

[0001] The invention relates to a device for detecting a pinching event of a motor-operated locking system of a vehicle according to the preamble of claim 1.

[0002] The invention further relates to a method for operating such a device and a device for preventing a pinching event of a motor-operated locking system of a vehicle.

[0003] DE 10 2020 002 817 A1 discloses a device for preventing a pinching event in a motor-operated locking system of a vehicle. The device comprises a sensor electrode which at least partially surrounds the edge of an opening in the vehicle that can be closed by means of a closure element. The device further comprises a microcontroller, a measuring pin coupled to the microcontroller and the sensor electrode, and a control pin coupled to the microcontroller and to the sensor electrode via a high-ohm electrical resistor. The microcontroller is designed to apply an electrical potential to the sensor electrode via the control pin and simultaneously measure the electrical potential of the sensor electrode and a distribution of negative charges on the sensor electrode at the measuring pin.As soon as the electrical potential measured at the measuring pin reaches a predetermined threshold, the microcontroller applies an electrical ground potential to the control pin, causing charges to flow back from the sensor electrode. Furthermore, the microcontroller is configured to record a time period from the threshold value being reached until a minimum threshold value of the electrical potential caused by the return flow of charges is reached. If the recorded time period deviates from a predetermined standard time period or from a standard time period recorded in a state without an imminent pinching event, it concludes that an imminent pinching event is occurring.

[0004] Furthermore, DE 10 2004 002 415 A1 discloses a device for controlling and monitoring an electrically driven window pane of a motor vehicle that is movable between an open position and a closed position. The device comprises a sensor having a sensor electrode that generates an electric field in an opening region of the closing element. The device further comprises a control unit connected to the sensor, which detects a change in the capacitance of the sensor electrode and provides a control signal. The control unit detects a capacitive change of the sensor electrode due to the presence of a moisture layer on the closing element.

[0005] EP 1 154 110 A2 describes an anti-pinch device for detecting the presence of an object in a sensing area. The anti-pinch device comprises a body portion, a ground electrode embedded in the body portion, and a sensor electrode arranged at a distance from the ground electrode and embedded in the body portion. The sensor electrode and the ground electrode are charged to different electrical potentials. The body portion is made of an electrically non-conductive material to insulate the sensor electrode from the ground electrode. The anti-pinch device further comprises a zone of reduced stiffness provided between the ground electrode and the sensor electrode, wherein the zone of reduced stiffness is arranged in the body portion and is co-extruded together with the body portion.Furthermore, the reduced-stiffness zone is provided in the form of an air gap in the body portion or in the form of a material with higher elasticity than that of the body portion, wherein the higher elasticity material is made of foam rubber. The body portion includes an electrically conductive region surrounding the sensor electrode and an electrically conductive region surrounding the ground electrode. Additionally, the anti-pinch device includes a device for generating input signals applied to the sensor electrode and receiving output signals from the sensor electrode.The device is capable of receiving both output signals, wherein the output signals change depending on a change in capacitance between the sensor electrode and the ground electrode in the case of the presence of a dielectric object in the sensing area, and the output signals change depending on a change in capacitance between the sensor electrode and the ground electrode in the case of the presence of a non-conductive object due to a change in the mutual position of the sensor electrode and the ground electrode.

[0006] Furthermore, US 2005 / 179445 A1 D2 describes a device for detecting a pinching event in a motor-operated locking system of a vehicle. Two capacitive sensor electrodes are provided, which are arranged at different distances from a vehicle opening. A voltage difference between the two electrodes is used to determine a pinching event.

[0007] The invention is based on the object of providing a device for detecting a pinching event of a motor-operated locking system of a vehicle, which is improved compared to the prior art, an improved method for operating such a device and an improved device for preventing a pinching event of a motor-operated locking system of a vehicle.

[0008] The object is achieved according to the invention by a device for detecting a pinching event of a motor-operated locking system of a vehicle, which has the features specified in claim 1, a method which has the features specified in claim 8, and a device for avoiding a pinching event of a motor-operated locking system of a vehicle, which has the features specified in claim 9.

[0009] Advantageous embodiments of the invention are the subject of the subclaims.

[0010] A device for detecting a pinching event in a motor-operated locking system of a vehicle comprises a sensor electrode that at least partially surrounds the edges of an opening in the vehicle that can be closed by at least one closure element. The sensor electrode is arranged in a sealing element that at least partially surrounds the opening.

[0011] According to the invention, a reference sensor electrode is provided which surrounds the edge of the opening of the vehicle at least in sections, wherein the reference sensor electrode is arranged at a distance from the sensor electrode in the sealing element and has a greater distance from the opening than the sensor electrode. Furthermore, a control unit is provided which is designed to apply an electrical potential to the sensor electrode and the reference sensor electrode for a charging process and a ground potential to the sensor electrode and the reference sensor electrode for a discharging process, and to detect a time duration until a minimum threshold value of the electrical potential for the sensor electrode and the reference sensor electrode is reached, caused by a backflow of charges via the ground potential.The control unit is further configured to determine a difference between the time duration detected for the sensor electrode and the time duration detected for the reference sensor electrode and, if the difference exceeds a predetermined threshold value and if the time duration detected for the sensor electrode deviates from a predetermined standard time duration or from a standard time duration detected in a state without an imminent pinching event, to conclude that an imminent pinching event is imminent.

[0012] The control unit and the sensor electrode are coupled to a first measuring pin, and the control unit and the reference sensor electrode are coupled to a second measuring pin. Furthermore, the control unit is coupled to a first control pin and the sensor electrode is coupled to the first control pin via a high-ohm electrical resistor, while the control unit is coupled to a second control pin and the reference sensor electrode is coupled to the second control pin via a high-ohm electrical resistor.The control unit is designed to apply the respective electrical potential to the sensor electrode and the reference sensor electrode via the first control pin and the second control pin, to simultaneously measure the electrical potential of the sensor electrode and a distribution of negative charges on the sensor electrode at the first measuring pin, and to simultaneously measure the electrical potential of the reference sensor electrode and a distribution of negative charges on the reference sensor electrode at the second measuring pin.Furthermore, the control unit is configured to apply the electrical ground potential to the control pins as soon as the electrical potentials measured at the measuring pins reach a predetermined threshold value, so that the charges flow back from the sensor electrode and the reference sensor electrode. The control unit is configured to record the respective time period from the threshold value being reached until a minimum threshold value of the electrical potential for the sensor electrode and the reference sensor electrode is reached, caused by the return flow of charges. This enables a simple design, reliable operation, and high robustness against interference, and can be implemented with low material and cost requirements.

[0013] The device is intended, for example, for use in a vehicle to detect a pinching event between the locking element and a vehicle structure that at least partially surrounds the locking element at its edge. For example, this is a motor-operated window pane and a vehicle structure that at least partially surrounds a window opening at its edge, or a motor-operated vehicle door and a vehicle structure that at least partially surrounds the vehicle door at its edge.

[0014] Safety requirements for so-called window regulator anti-pinch protection in vehicles require a high level of responsiveness, which cannot be ensured, for example, by a conventional current-based anti-pinch protection system. This is particularly due to the relatively high test object stiffness of 65 N / mm for testing the anti-pinch protection. The test object represents, for example, the properties of a child's finger. The responsiveness of known anti-pinch systems is also severely limited by a system time constant, which describes the time period from the control of a window regulator motor to the reaction of the window pane. A particular difficulty with frameless vehicle doors is that the guidance of the window pane in the upper block cannot be ensured due to freely placeable test object angles and test angle positions. This also applies to door anti-pinch protection systems.

[0015] By means of the device according to the invention, preventive anti-pinch protection can be implemented, which enables a reaction without the occurrence of a pinching force. This means that objects and body parts in a window runner or door opening and in a critical pinching area, for example, near a seal, can be detected before a pinching force occurs. This makes it possible to comply with the future safety requirement FMVSS-118. The device can be implemented with particularly low material and cost requirements. Detection is contactless and non-contact and is particularly robust. The detection range is, for example, 0.5 cm to 5 cm.In particular, increased robustness compared to capacitive systems is achieved through continuous recalibration of the discharge time, i.e., the time until the minimum threshold of the electrical potential caused by the return flow of charges is reached. This ensures very high robustness against moisture and system changes. Robustness is also achieved through possible synchronization with a window pane position, thus enabling activation of the anti-pinch protection only in critical areas. Furthermore, it is not necessary for a pinched object to be coupled to the ground potential.

[0016] In devices that use only one active sensor electrode, environmental properties that form a so-called baseline are determined by the same sensor electrode as a slow low-pass value, from which a fast low-pass value is also formed to determine a difference value. This means that it is not possible to distinguish whether changes are caused locally in the pinching area or globally, for example by external electric and magnetic fields. To avoid false detection, a high threshold must be specified and exceeded during the measurement performed using the sensor electrode, resulting in low sensitivity. Interactions between the sensor electrode and the charge distribution of a vehicle body further reduce the potential sensitivity, as stronger field interactions can occur than those caused by the pinching object.Pinched objects that remain in the pinching zone cannot be detected due to the continuous adaptation of the baseline to the current status. In contrast, the present device enables the use of lower thresholds while simultaneously maintaining high robustness against false detections due to the use of the reference sensor electrode to determine the environmental properties and the resulting robust baseline. This allows for the response to smaller difference values, which advantageously results in increased device sensitivity, reduced inertia in detecting a pinching event, and a reduction in the number of false detections.It is also possible to distinguish between local interactions in the pinching area, which primarily affect one of the electrodes, and interactions caused by external influences that affect both electrodes, such as interactions between the sensor electrode and the charge distribution of the vehicle body and external electric and magnetic fields. This means that it is possible to distinguish between local and global events.

[0017] In one possible embodiment of the device, the control unit is further configured to periodically execute the charging and discharging processes for the sensor electrode and the reference sensor electrode in a staggered manner, such that the charging and discharging processes of the sensor electrode begin after the charging and discharging processes of the reference sensor electrode have been completed, or vice versa. Thus, one of the two electrodes is always inactive, so that mutual interference between the electrodes during measured value acquisition can be effectively and easily avoided.

[0018] In another possible embodiment of the device, the sensor electrode is arranged in an inner sealing lip of the sealing element, and the reference sensor electrode is arranged in an outer sealing lip of the sealing element. This enables simple and protected integration of the two electrodes, with the reference sensor electrode being arranged near the sensor electrode, but not directly directed toward and / or located in the clamping area.

[0019] In a further possible embodiment of the device, the sensor electrode and the reference sensor electrode are each coupled to the ground potential via an electrical capacitor.

[0020] In another possible embodiment of the device, the sensor electrode and the reference sensor electrode are designed as sensor cables with an electrical conductor and surrounding electrical insulation. This enables a particularly simple, durable, and cost-effective design of the sensor electrode and reference sensor electrode. Furthermore, it allows for easy integration of the two electrodes into the sealing element.

[0021] In another possible embodiment of the device, a shielding electrode for shielding the sensor electrode and the reference sensor electrode against interference is arranged in a vehicle frame element or vehicle roof pillar that at least partially surrounds the opening. The shielding electrode enables shielding against interference occurring on a side facing away from the measuring area and consequently makes the device insensitive to interference. By arranging the shielding electrode in the vehicle frame element or vehicle roof pillar, reliable function of the shielding electrode is ensured, while also enabling easy integration into a vehicle.

[0022] In another possible embodiment of the device, the control unit is further configured to conclude that an imminent trapping event is imminent if, additionally, during the activated closing movement of the closure element, it is determined that the closure element is located in a predetermined critical area. This can prevent false triggering of anti-trap protection, particularly if a trapped object is moved from a region between the closure element and the surrounding vehicle structure during the closing movement of the closure element.

[0023] In the method according to the invention for operating a device mentioned above, the electrical potential is applied to the sensor electrode and the reference sensor electrode for the charging process and the ground potential is applied to the sensor electrode and the reference sensor electrode for the discharging process, respectively, and a time duration is recorded in each case until a minimum threshold value of the electrical potential for the sensor electrode and the reference sensor electrode is reached, caused by the backflow of charges via the ground potential. Furthermore, a difference between the time duration recorded for the sensor electrode and the time duration recorded for the reference sensor electrode is determined. If the difference exceeds a predetermined threshold value and if the time duration recorded for the sensor electrode deviates from a predetermined standard time duration or from a standard time duration recorded in a state without an imminent pinching event, an imminent pinching event is concluded.

[0024] Due to the use of the reference sensor electrode to determine the environmental properties and the resulting robust baseline, the method enables the use of lower thresholds and simultaneously leads to high robustness against false detections. This allows for a response to smaller difference values, which advantageously results in increased method sensitivity, reduced inertia in the detection of a pinching event, and a reduction in the number of false detections. It is also possible to distinguish between local interactions in the pinching area, which primarily affect one of the electrodes, and interactions caused by external influences that affect both electrodes, such as interactions between the sensor electrode and the charge distribution of the vehicle body and external electric and magnetic fields. This means that it is possible to distinguish between local and global events.

[0025] The device according to the invention for preventing a pinching event in a motor-operated locking system of a vehicle comprises a previously mentioned device for detecting a pinching event and at least one control unit for controlling a motor drive of the locking element. The control unit is designed to stop and / or reverse a closing movement of the locking element in the event of an imminent pinching event. The device enables particularly reliable prevention of pinching events while simultaneously minimizing false detections and false triggering.

[0026] Embodiments of the invention are explained in more detail below with reference to drawings.

[0027] Showing: Fig. 1 schematically shows an electrical circuit diagram of a device for detecting a jamming event of a motor-operated locking system of a vehicle, Fig. 2 schematically shows a section of a side view of a vehicle, Fig. 3 schematically shows a perspective view of a sectional view of a section of the vehicle according to Figure 2in the area of ​​a vehicle structure and a sealing element, Fig. 4 schematically shows a perspective view of a sectional representation of a section of a vehicle door in the area of ​​a sealing element, Fig. 5 schematically shows a flow diagram of a possible embodiment of a method for detecting a pinching event of a motor-operated locking system of a vehicle, Fig. 6 schematically shows a flow diagram of a possible embodiment of a method for avoiding a pinching event of a motor-operated locking system of a vehicle and Fig. 7 schematically shows a vehicle door with a window opening and a window pane.

[0028] Corresponding parts are provided with the same reference numerals in all figures.

[0029] In Figure 1is an electrical circuit diagram of a possible embodiment of a device 1 for detecting a jamming event of a motor-operated locking system of a Figure 2 vehicle 2 shown in more detail.

[0030] The device 1 comprises a sensor electrode 3, which has a closure element 4 (shown in Figure 7 ) closable opening O (shown in Figure 2 ) of the vehicle 2 at least in sections. The sensor electrode 3 has, for example, a length of more than 0.1 m up to 5 m. The device 1 further comprises a reference sensor electrode 15, which also surrounds the closable opening O of the vehicle 2 at least in sections at the edge. The reference sensor electrode 15 is arranged at a greater distance from the opening O than the sensor electrode 3.

[0031] The sensor electrode 3 and the reference sensor electrode 15 are arranged together in a housing which at least partially surrounds the opening O and is inserted into the Figures 2 to 5 sealing element 10 shown in more detail.

[0032] The device 1 further comprises a control unit 5, for example a microcontroller, a measuring pin 6 coupled to the control unit 5 and the sensor electrode 3, and a control pin 8 coupled to the control unit 5 and, via a high-ohmic electrical resistor 7, to the sensor electrode 3.

[0033] Furthermore, the device 1 comprises a measuring pin 16 coupled to the control unit 5 and the reference sensor electrode 15 and a control pin 18 coupled to the control unit 5 and, via a high-ohmic electrical resistor 17, to the reference sensor electrode 15.

[0034] The sensor electrode 3 and the reference sensor electrode 15 can each be coupled to a ground potential GND of the vehicle 2 via an electrical capacitor 9, 19. In embodiments not shown in detail, the capacitors 9, 19 can be omitted.

[0035] The sensor electrode 3 and the reference sensor electrode 15 are each designed as a sensor cable with an electrical conductor 3.1, 15.1 and surrounding electrical insulation 3.2, 15.2. The electrical conductors 3.1, 15.1 are designed, for example, as copper conductors, and the electrical insulation 3.2, 15.2 is designed, for example, as plastic or rubber insulation. The sensor cables each have a diameter of 0.5 mm to 2 mm, for example. In particular, the sensor electrode 3 and the reference sensor electrode 15 are designed identically to improve comparability of the measurement results acquired using them.

[0036] The control unit 5 is designed to apply an electrical potential to the sensor electrode 3 via the control pin 8 and, at the same time, to measure the electrical potential of the sensor electrode 3 and the resulting distribution of negative charges on the sensor electrode 3 at the measuring pin 6. As soon as the electrical potential measured at the measuring pin 6 reaches a predetermined threshold value, the control unit 5 applies the electrical ground potential GND to the control pin 8, so that negative charges and positive charges flow back from the sensor electrode 3. In this case, the control unit 5 records a time period from the threshold value being reached until a minimum threshold value of the electrical potential is reached, caused by the return flow of the charges.

[0037] Furthermore, the control unit 5 is designed to apply an electrical potential to the reference sensor electrode 15 via the control pin 18, analogous to the procedure on the sensor electrode 3, and simultaneously to measure the electrical potential of the reference sensor electrode 15 and a resulting distribution of negative charges on the reference sensor electrode 15 at the measuring pin 16. As soon as the electrical potential measured at the measuring pin 16 reaches a predetermined threshold value, the control unit 5 applies the electrical ground potential GND to the control pin 18, so that negative charges and positive charges flow back from the reference sensor electrode 15. Here, too, the control unit 5 records a time period from the threshold value being reached until a minimum threshold value of the electrical potential is reached, caused by the return flow of the charges.

[0038] Here, environmental properties are determined using the reference sensor electrode 15, from which a so-called baseline is created. This baseline represents external global conditions, i.e., influences that act on both the sensor electrode 3 and the reference sensor electrode 15. These influences include, for example, interactions between the sensor electrode 3 and the reference sensor electrode 15 with a charge distribution of a vehicle body, external charge distributions, external electric and magnetic fields, etc. In particular, it is assumed that an external global change occurs significantly slower than the cycle times used, for example, ~ 50 µs.

[0039] The charging and discharging processes for the sensor electrode 3 and for the reference sensor electrode 15 are periodically staggered such that the charging and discharging processes of the sensor electrode 3 start after the charging and discharging processes of the reference sensor electrode 15 are completed, or vice versa. This means that one of the two electrodes is always inactive, so that mutual interference between the electrodes can be avoided.

[0040] Furthermore, a difference between the time duration recorded for sensor electrode 3 and the time duration recorded for reference sensor electrode 15 is determined. If the difference exceeds a predetermined threshold and the time duration recorded for sensor electrode 3 deviates from a predetermined standard time duration or from a standard time duration recorded in a state without an imminent pinching event, control unit 5 concludes that an imminent pinching event is occurring.

[0041] This deviation from the standard duration results from the fact that an external influence of an object, for example a human extremity, fixes negative charges in the sensor electrode 3 and thus prevents them from flowing back, and consequently causes inhomogeneities in a charge distribution within the sensor electrode 3.

[0042] By comparing the measured values ​​acquired by sensor electrode 3 with the baseline, differences of local origin, such as the approach of body parts, can be reliably detected. This enables high robustness and more stable detection of local, sluggish effects (> 50 ms). Calibration of sensor electrode 3 to the environment using slow low-pass filters is not required.

[0043] Figure 2shows a section of a side view of a vehicle 2, wherein the vehicle 2 includes frameless vehicle doors (not shown). In such vehicle doors, closure elements 4 designed as window panes are sealed by means of at least one sealing element 10 that at least partially surrounds the edge of the opening O, in this case a window opening, when the vehicle door is closed and when the window pane is closed. In the illustrated embodiment, the sealing element 10 is arranged on a vehicle structure 11 formed by a roof pillar.

[0044] In Figure 3 is a perspective view of a sectional view of a section of the vehicle 2 according to Figure 2 in the area of ​​the vehicle structure 11, designed as a roof pillar, and the sealing element 10. The sealing element 10 is designed as a roof seal with a so-called bubble shape.

[0045] To avoid a pinching event between the window pane and the sealing element 10 by detecting an imminent pinching event as described in Figure 1 The sensor electrode 3 is arranged in the sealing element 10, completely and directly surrounded by a sealing material 10.1 or, alternatively, in a cavity 10.2. The sensor electrode 3 is arranged, in particular, in an inner sealing lip of the sealing element 10.

[0046] Furthermore, the reference sensor electrode 15 is arranged in the sealing element 10 completely and directly surrounded by the sealing material 10.1 or alternatively in the cavity 10.2 such that it has a greater distance from the opening O than the sensor electrode 3. The reference sensor electrode 15 is arranged in particular in an outer sealing lip of the sealing element 10.

[0047] Furthermore, a shielding electrode 13 is arranged to shield the sensor electrode 3 and the reference sensor electrode 15 against interference occurring in the area of ​​the vehicle structure 11, which is designed as a roof pillar. Alternatively, the shielding electrode 13 can also be designed as a shielded cable with an electrical conductor, for example a copper conductor, and surrounding electrical insulation, for example a plastic or rubber insulation.

[0048] When using the shield electrode 13, the sensor electrode 3 and the reference sensor electrode 15 are not coupled to the electrical ground potential GND via the capacitors 9, 19, for example. The shield electrode 13 is in particular coupled to the ground potential GND and is arranged in particular between the sensor electrode 3 and the edge of the opening O.

[0049] The detection of an imminent trapping event is carried out in the illustrated embodiment of the device 1 analogously to the described detection according to Figure 1 , wherein the shielding electrode 13 provides a directed, in particular downward-directed measuring range and shields against interference occurring on a side facing away from the measuring range. Thus, the device 1 is insensitive to interference.

[0050] Figure 4 shows a perspective view of a sectional representation of a section of a vehicle door 12 in the region of a sealing element 10. The vehicle door 12 is designed as a so-called frame door, the frame of which forms the vehicle structure 11, on which a sealing element 10 is arranged to seal the window pane in the closed state. The sealing element 10 is designed as a frame seal of the frame of the vehicle door 12.

[0051] For detecting a pinching event between the window pane and the sealing element 10 by detecting an imminent pinching event as described in Figure 1 A sensor electrode 3 and a reference sensor electrode 15 are arranged in the sealing element 10, completely and directly surrounded by the sealing material 10.1 or in the cavity 10.2. The reference sensor electrode 15 is arranged such that it is at a greater distance from the opening O than the sensor electrode 3.

[0052] Furthermore, a shielding electrode 13 is arranged to shield the sensor electrode 3 and the reference sensor electrode 15 against interference occurring in the area of ​​the vehicle structure 11, which is designed as the frame of the vehicle door 12. Alternatively, the shielding electrode 13 can also be designed as a shielded cable with an electrical conductor, for example a copper conductor, and surrounding electrical insulation, for example a plastic or rubber insulation.

[0053] When using the shield electrode 13, the sensor electrode 3 and the reference sensor electrode 15 are not coupled to the electrical ground potential GND via the capacitors 9, 19, for example. The shield electrode 13 is in particular coupled to the ground potential GND and is arranged in particular between the sensor electrode 3 and the edge of the opening O.

[0054] The detection of an imminent trapping event is carried out in the illustrated embodiment of the device 1 analogously to the described detection according to Figure 1 , wherein the shielding electrode 13 provides a directed, in particular downward-directed measuring range and shields against interference occurring on a side facing away from the measuring range. Thus, the device 1 is insensitive to interference.

[0055] Figure 5 shows a flowchart of a possible embodiment of a method for detecting a pinching event of a motor-operated locking system of a vehicle 2.

[0056] First, in a first method step S1, the charging phase is carried out by applying a positive electrical potential to the reference sensor electrode 15 via the control pin 18, so that negative charges migrate to the reference sensor electrode 15. At the same time, the electrical potential of the reference sensor electrode 15 and the resulting distribution of the negative charges on the reference sensor electrode 15 are measured at the measuring pin 16.

[0057] At a first branch V1, a check is made to determine whether the electrical potential measured at measuring pin 16 has reached the specified threshold. If this is not the case, represented by a "no" branch N1, the charging phase continues.

[0058] If the electrical potential measured at measuring pin 16 has reached the specified threshold value, represented by a "Yes" branch J1, the control unit 5 applies the electrical ground potential GND to the control pin 18 in a second method step S2, so that the discharge phase begins and negative charges and positive charges flow back from the reference sensor electrode 15. The control unit 5 records the time from reaching the threshold value until the minimum threshold value of the electrical potential caused by the return flow of charges is reached. A timer reset occurs before the discharge phase begins.

[0059] The discharge phase is executed until the minimum threshold is reached. In a second branch V2, the control unit 5 checks whether the minimum threshold has been reached. If this is not the case, represented by a "No" branch N2, the timer is incremented in a third method step S3.

[0060] If, on the other hand, the minimum threshold value has been reached, represented by a yes branch J2, a timer value, i.e. the measured time period, is equated to a residual charge quantity in a fourth method step S4.

[0061] Subsequently, in a fifth method step S5, an asymmetric filtering of the timer value is carried out by means of an asymmetric low-pass filter, whereby a shortening of the discharge time is given greater weight and thus a relationship to a distance of a detectable object can be established.

[0062] Subsequently, the process steps S1 to S5 are carried out analogously for the sensor electrode 3 and a correspondingly filtered timer value T2, i.e. a duration of the discharge, is formed.

[0063] As soon as the filtered timer value T1 for the reference sensor electrode 15 and the timer value T2 for the sensor electrode 3 are available, a sixth method step S6 involves forming a difference between the two timer values ​​T1, T2, i.e., between the time period recorded for the sensor electrode 3 and the time period recorded for the reference sensor electrode 15 until the minimum threshold value of the electrical potential is reached. In this case, the timer value T1 of the reference sensor electrode 15 is subtracted from the timer value T2 for the sensor electrode 3.

[0064] In a branch V3, it is checked whether the difference value is constantly negative, i.e., whether the timer value T1 of the reference sensor electrode 15 is constantly greater than the timer value T2 for the sensor electrode 3. If this is the case, represented by a "yes" branch J3, an offset calculation is performed in a seventh process step S7, and this offset is used to calibrate the reference sensor electrode 15.

[0065] If the difference value is positive or constantly negative, i.e. if the timer value T1 of the reference sensor electrode 15 is smaller than the timer value T2 for the sensor electrode 3, represented by a no branch N3, the difference value is filtered by means of a low-pass filter in an eighth method step S8.

[0066] Subsequently, a further branch V4 checks whether the difference value exceeds the specified threshold. If this is the case, represented by a "yes" branch J4, an object is detected in a ninth process step S9, and it is concluded that an imminent entrapment event is imminent. If this is not the case, represented by a "no" branch N4, the process is restarted according to a process step S10.

[0067] Because the filtering of the timer values ​​T1, T2 is identical for both electrodes at the discharge times, identical values ​​result under constant environmental conditions. This means that if the discharge times of the reference sensor electrode 15 and the sensor electrode 3 are the same, it can be concluded that no object is present in the pinching area.

[0068] In Figure 6a flowchart of a possible embodiment of a method for preventing a pinching event of a motor-operated locking system of a vehicle 2, in particular a window pane, is shown.

[0069] This process follows directly on from the ninth process step S9 of the Figure 5 The method shown in the figure is used, whereby a branch V5 checks whether a window closing signal F is present. If this is not the case, represented by a no branch N5, the method according to Figure 5 restarted.

[0070] However, if a window closing signal F is present and an object has previously been detected, represented by a yes branch J5, a further branch V6 checks whether a window pane position POS of an upper edge of the pane is in a Figure 7critical area K shown in more detail. If this is not the case, represented by a no branch N6, the system returns to the previous branch V5 and checks for the presence of the window closing signal F.

[0071] If, on the other hand, the window pane position POS is in the critical area K, represented by a yes branch J6, a movement of the window pane is stopped or reversed in an eleventh method step S11 in order to avoid a pinching event.

[0072] Figure 7 shows a vehicle door 12 with an opening O designed as a window opening and a closure element 4 designed as a window pane, wherein the vehicle door 12 is designed according to the Figure 4illustrated vehicle door 12. A critical region K is shown below an upper edge of the opening O, wherein a lower edge of the critical region K represents in particular the region in which a pinching event between an upper edge of the window pane and the upper edge of the opening O is likely.

Claims

1. Device (1) for detecting a jamming incident of a motor-operable locking system of a vehicle (2), - comprising a sensor electrode (3) which peripherally surrounds, at least in portions, an opening (O) of the vehicle (2) which can be closed by means of at least one locking element (4), wherein - the sensor electrode (3) is arranged in a sealing element (10) which at least partially surrounds the opening (O), wherein - a reference sensor electrode (15) is provided which peripherally surrounds, at least in portions, the opening (O) of the vehicle (2), - the reference sensor electrode (15) is arranged in the sealing element (10) at a distance from the sensor electrode (3) and is at a greater distance from the opening (O) than the sensor electrode (3), - a control unit (5) is provided, - the control unit (5) and the sensor electrode (3) are coupled to a first measuring pin (6), - the control unit (5) and the reference sensor electrode (15) are coupled to a second measuring pin (16), - the control unit (5) is coupled to a first control pin (8) and the sensor electrode (3) is coupled to the first control pin (8) via a high-ohm electrical resistor (7), - the control unit (5) is coupled to a second control pin (18) and the reference sensor electrode (15) is coupled to the second control pin (18) via a high-ohm electrical resistor (17), - the control unit is configured: - to apply an electrical potential to the sensor electrode (3) and the reference sensor electrode (15) via the first control pin (8) and the second control pin (18) respectively for a charging process so that negative charges migrate to the sensor electrode (3) and the reference sensor electrode (15) respectively, - to apply a ground potential (GND) to the sensor electrode (3) and the reference sensor electrode (15) respectively for a discharging process so that negative charges and positive charges flow back from the sensor electrode (3) and the reference sensor electrode (15) respectively, - to simultaneously measure at the first measuring pin (6) the electrical potential of the sensor electrode (3) and a distribution of negative charges on the sensor electrode (3) resulting therefrom, - to simultaneously measure at the second measuring pin (16) the electrical potential of the reference sensor electrode (15) and a distribution of negative charges on the reference sensor electrode (15) resulting therefrom, - to apply the electrical ground potential (GND) to the control pins (8, 18) as soon as the electrical potentials measured at each of the measuring pins (6, 16) reach a predetermined threshold value, so that the charges flow back from the sensor electrode (3) and the reference sensor electrode (15), - to record a duration for the sensor electrode (3) and the reference sensor electrode (15) respectively until a minimum threshold value of the electrical potential is reached, which minimum threshold value is caused by a return flow of charges via the ground potential (GND), - to determine a difference between the duration recorded for the sensor electrode (3) and the duration recorded for the reference sensor electrode (15) and - to conclude that a jamming incident is imminent if the difference exceeds a predetermined threshold value and if the duration recorded for the sensor electrode (3) deviates from a predetermined standard duration or from a standard duration recorded in a state recorded without an imminent jamming event.

2. Device (1) according to claim 1, characterized in that the control unit (5) is further configured to carry out the charging process and the discharging process for the sensor electrode (3) and the reference sensor electrode (15) in a periodically staggered manner such that the charging process and the discharging process of the sensor electrode (3) start after the charging process and the discharging process of the reference sensor electrode (15) have been completed, or vice versa.

3. Device (1) according to claim 1 or claim 2, characterized in that - the sensor electrode (3) is arranged in an inner sealing lip of the sealing element (10) and - the reference sensor electrode (15) is arranged in an outer sealing lip of the sealing element (10).

4. Device (1) according to any of the preceding claims, characterized in that the sensor electrode (3) and the reference sensor electrode (15) are each coupled to the ground potential (GND) via an electrical capacitor (9, 19).

5. Device (1) according to any of the preceding claims, characterized in that the sensor electrode (3) and the reference sensor electrode (15) are each designed as a sensor cable comprising an electrical conductor (3.1, 15.1) and an electrical insulator (3.2, 15.2) surrounding said conductor.

6. Device (1) according to any of the preceding claims, characterized in that a shielding electrode (13) for shielding the sensor electrode (3) and the reference sensor electrode (15) against any interference that occurs is arranged in a vehicle frame element or vehicle roof beam which surrounds, at least in portions, the opening (O).

7. Device (1) according to claim 1, characterized in that the control unit (5) is further configured to conclude that a jamming incident is imminent if, in addition, the locking element (4) is located in a predetermined critical region (K) when the closing movement of the locking element (4) is activated.

8. Method for operating a device (1) according to any of the preceding claims, wherein - the electrical potential for the charging process and the ground potential (GND) for the discharging process are applied to the sensor electrode (3) and the reference sensor electrode (15) respectively, - a duration is recorded for the sensor electrode (3) and the reference sensor electrode (15) respectively until a minimum threshold value of the electrical potential is reached, which minimum threshold value is caused by the return flow of the charges via the ground potential (GND), - a difference between the duration recorded for the sensor electrode (3) and the duration recorded for the reference sensor electrode (15) is determined, and - if the difference exceeds a predetermined threshold value and if the duration recorded for the sensor electrode (3) deviates from a predetermined standard duration or from a standard duration recorded in a state recorded without an imminent jamming incident, it is concluded that a jamming incident is imminent.

9. Device for preventing a jamming incident of a motor-operable locking system of a vehicle (2), comprising - a device (1) for detecting a jamming incident according to any of claims 1 to 7 and - at least one control unit (5) for controlling a motor drive of the locking element (4), wherein the control unit (5) is designed to stop and / or reverse a closing movement of the locking element (4) in the event of an imminent jamming incident.

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