Parking lock device, vehicle comprising a parking lock device, and method for monitoring a parking lock device

Abstract

The invention relates to a parking lock device (1) and to a method for monitoring same, wherein the parking lock device (1) comprises a parking lock wheel (2) that can be coupled to an output of a vehicle, a locking pawl (3), an actuating mechanism (4) and an electric motor (5), wherein, when the parking lock device (1) is activated, the actuating mechanism (4) can be actuated by means of the electric motor (5) in order to transfer the locking pawl (3) into a locking position and to block the parking lock wheel (2). When the parking lock device (1) is activated, the parking lock wheel (2) is located either in a first rotational position (ToT) or in a second rotational position (ToG), wherein the locking element (31) lies opposite a tooth (2a) in the first rotational position (ToT) and lies opposite a tooth gap (2b) of the parking lock wheel in the second rotational position (ToG). A first characteristic operating value curve (I1) can be assigned to an activation of the parking lock device (1) in the first rotational position (ToT) and a second characteristic operating value curve (I2) of the electric motor (5) can be assigned to an activation of the parking lock device (1) in the second rotational position (ToG). According to the invention, a monitoring device (10) is provided, by means of which it is detected how often, during a sequence of multiple activations of the parking lock device (1), the second characteristic operating value curve (I2) has occurred directly one after the other, and a fault of the parking lock device (1) is extrapolated depending on the detected number n of the second characteristic operating value curves (I2) occurring directly one after the other.

Description

[0001] Description

[0002] title

[0003] Parking barrier device, vehicle with a parking barrier device and method for monitoring a parking barrier device

[0004] State of the art

[0005] In the prior art, devices referred to as parking locks are known, comprising a parking lock wheel that can be coupled to a vehicle's drive, a pawl, an actuating mechanism, and an electric motor. The parking lock wheel has teeth and tooth gaps distributed around its circumference. When the parking lock device is activated, the actuating mechanism can be operated by the electric motor to move the pawl into a locking position. In the locking position, a locking element of the pawl engages in a tooth gap of the parking lock wheel to block the parking lock wheel. Such a parking lock device is known, for example, from DE 102021 205592 A1. It is also known to use a sensor to monitor parking lock devices, for example, the position of a moving part of the actuating mechanism, as is the case, for example, in DE 102020202 682 A1.In this script, for example, a magnetic sensor detects whether the parking lock device is in the neutral position or the locked position.

[0006] Disclosure of the invention

[0007] The invention relates to a parking lock device comprising a parking lock wheel that can be coupled to a vehicle output, a pawl, an actuating mechanism, and an electric motor, wherein the parking lock wheel has teeth and tooth gaps arranged distributed around its circumference, wherein, upon activation of the parking lock device, the actuating mechanism can be actuated by means of the electric motor to move the pawl into a locking position, wherein in the locking position a locking element of the pawl engages in a tooth gap of the parking lock wheel to block the parking lock wheel, wherein, upon activation of the parking lock device, the parking lock wheel can be in either a first rotational position or a second rotational position, wherein the locking element is opposite a tooth in the first rotational position and opposite a tooth gap in the second rotational position.wherein a first characteristic operating value profile of the electric motor is associated with activation of the parking lock device in the first rotational position and a second characteristic operating value profile of the electric motor is associated with activation of the parking lock device at least in the second rotational position. According to the invention, an electronic monitoring device is associated with the parking lock device, wherein the monitoring device has first detection means which detect whether the first characteristic operating value profile or the second characteristic operating value profile occurs during activation of the electric motor, wherein the monitoring device has second detection means which detect how often the second characteristic operating value profile has occurred immediately one after the other in a sequence of multiple activations of the parking lock device, and wherein the monitoring device has evaluation means.which, depending on a number n of immediately consecutive second characteristic operating value curves detected by the second detection means, conclude that there is a fault and output a corresponding fault signal.

[0008] Furthermore, the invention relates to a method for monitoring such a parking lock device, in which an electronic monitoring device detects whether the first characteristic operating value curve or the second characteristic operating value curve has occurred when the electric motor is activated, and recognizes how often the second characteristic operating value curve has occurred immediately one after the other in a sequence of multiple activations of the parking lock device, and depending on a detected number n of the second characteristic operating value curves that have occurred immediately one after the other, a fault is inferred and a corresponding fault signal is output.

[0009] A rotational position refers to the rotational position of the parking lock wheel relative to the locking element. In the neutral position, the locking element is spaced away from the circumference of the parking lock wheel. Rotation of the parking lock wheel causes the teeth and gaps to pass the locking element without contact. Since the parking lock wheel is coupled to a vehicle output shaft during operation of the parking lock mechanism, a random rotational position of the parking lock wheel is established when the vehicle stops. In this position, the locking element is either opposite a tooth or a gap of the parking lock wheel. Thus, in a first rotational position, the locking element is opposite a tooth, and in a second rotational position, it is opposite a gap. The first and second rotational positions repeat alternately as the parking lock wheel rotates.A parking lock wheel with, for example, eight teeth and eight gaps, therefore, enters the first rotational position eight times and the second rotational position eight times during a 360° rotation, with the first and second rotational positions alternating.

[0010] When the parking lock is activated, the locking element can be acted upon against the outer contour of the parking lock wheel by means of the actuating mechanism. The actuating mechanism may, but is not limited to, use a spring for this purpose. In particular, it is possible for the actuating mechanism to have a rod that is movable by means of the electric motor, with a plunger slidably mounted on the rod. The plunger is supported against the rod by a spring, and when the parking lock is activated, the plunger is pressed against the pawl to move the pawl into the locked position.

[0011] A state in which the locking element is opposite a tooth gap is defined by the fact that, upon activation of the parking lock mechanism, the locking element can engage the tooth gap through a pivoting movement of the pawl without first contacting the teeth of the parking lock wheel. A state in which the locking element is opposite a tooth is defined by the fact that, upon pivoting of the pawl towards the parking lock wheel, a portion of the locking element's outer contour will initially abut a tooth of the parking lock wheel. If the parking lock wheel is initially in its first rotational position when the parking lock mechanism is activated, the locking element will initially abut a tooth of the parking lock wheel with at least a portion of its contour and be pressed against it.Only after a slight rotation of the parking lock wheel by a small angle (for example, triggered by a slight rolling movement of the vehicle) does the locking element then engage in a tooth gap adjacent to this tooth to block the parking lock wheel. If, on the other hand, the parking lock wheel is initially in the second rotational position when the parking lock mechanism is activated, the locking element immediately engages in a tooth gap of the parking lock wheel to block the parking lock wheel and thus prevent the vehicle from rolling away.

[0012] It is understood that the probability of the parking lock wheel being in the first or second rotational position when the parking lock device is activated depends not only on the rotation angle of the parking lock wheel, but also on the geometric properties of the teeth and tooth gaps, as well as the dimensions of the locking element. Teeth and tooth gaps can preferably be evenly distributed around the circumference of the parking lock wheel. It is possible, but not necessary, for the width of a tooth to correspond to the width of a tooth gap. Regardless, for the locking element to engage in a tooth gap, its width, viewed in one circumferential direction of the parking lock wheel, must be smaller than the width of the tooth gap.When the locking element engages in the tooth gap, a residual air gap remains, viewed circumferentially, between the edges of the locking element and the adjacent flanks of the two teeth bordering the tooth gap. This gap is larger the smaller the width of the locking element in the circumferential direction. The larger this residual air gap, the more likely it is that, in a random rotational position of the parking lock wheel, the second rotational position will occur in which the locking element is opposite a tooth gap and can engage directly into the tooth gap upon activation.

[0013] The operating characteristic of an electric motor represents the change over time of an operating characteristic, for example, the change over time of an electric current flowing through the electric motor when the parking lock mechanism is activated. The electric motor can have a stator and a rotor. The stator can, for example, have a stator winding. The current can, for example, flow through the stator winding. The operating characteristic of the electric motor can depend on the time-dependent force transmission of the actuating mechanism driven by the electric motor to the locking pawl.

[0014] When the parking lock mechanism is activated in the first and second rotational positions, a measurement of an operating characteristic, such as the time course of the electric motor's current or a related physical quantity, can demonstrate that the operating characteristic in the first rotational position differs from that in the second. This is also due to the fact that in the first rotational position, the locking element is initially pressed against a tooth, while in the second rotational position it can engage directly in a tooth gap.

[0015] Although several operating curves measured in the same rotational position are not exactly identical and exhibit slight fluctuations, they nevertheless share a characteristic pattern characterized by the same temporal maxima and minima, rising or falling edges, or average values. All operating curves in the first rotational position correspond to a first characteristic operating curve, specifically a first characteristic current curve, while the operating curves of the electric motor in the second rotational position correspond to a second characteristic operating curve, specifically a second characteristic current curve.

[0016] Whether a temporal operating value profile observed during the activation of the parking barrier corresponds to the first or the second characteristic operating value profile can be easily determined by analyzing, for example, the occurrence of maxima and minima or the slope of the edges at specific times, or by calculating the average value. This analysis can be easily performed by a program in a data processing electronic device. While not strictly necessary, artificial intelligence-trained systems, for example, which have been trained on a sufficient number of operating profiles, can also be used for this purpose.The training data obtained can then be transferred to an electronic control unit, which is used as a monitoring device for the parking lock system, so that the first or second characteristic operating value profile can be easily recognized in a computer system.

[0017] An electronic monitoring device associated with the parking lock mechanism is understood to be an electronic device capable of recording and evaluating the temporal operating characteristic curves of an electric motor. This can be a separate control unit of the vehicle or an electronic device integrated directly into the parking lock mechanism. The monitoring device is designed to recognize whether the first characteristic operating characteristic curve or the second characteristic operating characteristic curve occurred when the electric motor was activated, and how often the second characteristic operating characteristic curve occurred consecutively in a sequence of multiple activations of the parking lock mechanism. For this purpose, the monitoring device can record the current curve of the electric motor.Depending on the recorded number n of the second characteristic operating value curves that occurred immediately one after the other, the monitoring device concludes that there is a fault and outputs a corresponding fault signal.

[0018] Advantages of the invention

[0019] If, in the case of parking lock devices known in the prior art, an interruption occurs in the force transmitted from the actuating mechanism to the locking pawl during activation, the existing sensors often cannot detect the fault, or cannot detect it correctly, so that the failure of the parking lock device goes unnoticed. While additional sensors can partially solve this problem, they are quite expensive and complex to install. The parking lock device according to the invention advantageously enables the detection of a fault in the parking lock device even if there is mechanical damage or a breakage of a force-transmitting part of the actuating mechanism. Additional sensors are not required for this.The solution according to the invention advantageously distinguishes between activation of the parking lock device in the first rotational position and activation in the second rotational position based on an evaluation of a characteristic operating characteristic of the electric motor. The invention utilizes the fact that, in the event of a mechanical failure of the actuating mechanism, an operating characteristic of the electric motor, in particular a current characteristic of the electric motor, can be recorded which is very similar to the operating characteristic in the second rotational position. This can be attributed, for example, to the fact that, in the event of a failure of a part of the actuating mechanism acting on the pawl, the electric motor experiences a power consumption over time that corresponds to the current consumption over time when the locking element is directly engaged in a tooth gap, since even in the event of a malfunction the locking element cannot be pressed against a tooth.

[0020] In such a malfunction, a characteristic operating characteristic of the electric motor can be recorded, which corresponds to the second characteristic operating characteristic. This means that the second characteristic operating characteristic occurs when the locking element can engage directly into a tooth gap in the second rotational position or when a mechanical malfunction is present. Therefore, the probability of the second characteristic operating characteristic occurring multiple times in succession is a criterion indicating a fault in the parking lock mechanism. Consequently, depending on the recorded number n of consecutive second characteristic operating characteristics, a fault in the parking lock mechanism can be inferred without the need for an additional sensor.

[0021] Advantageous embodiments and further developments of the invention enable the features contained in the dependent claims.

[0022] A probability PTOG, which indicates whether the second rotational position is present upon a single activation of the parking lock device, can be derived from the relationship PTOG — ( Cap N Teeth / 0°

[0023] to be calculated, whereby

[0024] Nreeth is the number of teeth of the parking lock wheel and

[0025] <p Gap Specifies an angular measurement which, in a state where the locking element engages in a tooth gap, is assigned to a residual air gap between the locking element and the adjacent flanks of neighboring teeth. This probability PT O The probability value G, representing the probability, can be stored in a memory of the electronic monitoring device.

[0026] Advantageously, the evaluation means of the monitoring device, depending on the value stored in the memory representing the probability PTOG, infer a fault and output a corresponding fault signal. This is particularly advantageous because, with a uniform distribution of teeth and tooth gaps around the circumference of the parking lock wheel, the presence of the first rotational position upon activation of the parking lock device is much more likely than the presence of a second rotational position. For a parking lock wheel with eight teeth and eight tooth gaps (Nreeth = 8) and an angular dimension <p GapThe residual air gap of, for example, 9° results from the aforementioned relationship: PTOG = 0.2. Therefore, the probability of the second rotational position being present is significantly lower at 0.2 or 20% than the probability of the first rotational position being present at 0.8 or 80%. Physically, this is because, due to its width, the locking element must be positioned relatively centrally opposite the tooth gap to engage directly into the gap, whereas in all other cases, the locking element will abut a tooth with a corner or completely.

[0027] Since the probabilities for multiple occurrences of independent events are multiplicative, the probability of the second rotation position occurring consecutively becomes increasingly lower with the number n of cases. Therefore, the evaluation tools can advantageously calculate an error probability value PError(n), representing the probability of a fault in the parking lock mechanism, from the number n of consecutive second characteristic operating value profiles detected by the second detection tools and from the probability value representing the probability PTOG. In particular, it is possible to derive the error probability value PError(n) from the relationship

[0028] P Error ) = 1 - PTOG( L)

[0029] to calculate, where P-roG(n) is calculated from the fact that the value is the probability PT OG represents the probability value according to the relationship

[0030] Procin) = (PTOGY 1

[0031] is multiplied by itself n times, where n is the recorded number of consecutive second characteristic operating value curves.

[0032] The evaluation tools can advantageously compare the error probability value PError(n) with a threshold value and, depending on the comparison, infer an error. For example, if the second characteristic operating value curve was detected eight times in a row, then in the example above, P roC (n=8) = (PTOG) 8 = 0.000256% and P £-rror(n=8) = 99.999744%. This indicates that a very rare condition has occurred. If the threshold for PError(n) is set to 95%, for example, an error is detected because the threshold is exceeded. From all this, it can be seen that even with a small number n of consecutive detections of the second characteristic current waveform, the occurrence of an error is highly probable. This can also happen with a value of n that is significantly less than 8. Thus, in another embodiment, an error can be inferred after only two or three consecutive occurrences (i.e., n=2 or n=3).

[0033] The monitoring device can advantageously include a warning device which, depending on the occurrence of the fault signal, generates an alarm signal or initiates an emergency measure. For example, a warning light can signal a parking lock fault to the driver of a vehicle, an emergency braking device can be activated, or an emergency call can be placed.

[0034] A further advantage is a vehicle equipped with a parking lock device as described above, wherein the monitoring device includes third detection means that record information about whether the vehicle is being moved. The evaluation means can be configured, depending on the number n of consecutive second characteristic operating value profiles detected by the second detection means and depending on the information recorded by the third detection means, to conclude that a fault has occurred only if the vehicle was moved between each consecutive second characteristic operating profile. This measure advantageously prevents false alarms if the vehicle is stationary and the parking lock device is activated several times in succession while the vehicle is stationary.Since the parking lock wheel no longer rotates when the vehicle is stationary, or only rotates minimally by a small angle into the locked position, it is possible that the monitoring device, if the parking lock is engaged multiple times, might detect a number n of consecutive second characteristic operating value profiles if the locking element happens to be in the second rotational position opposite a tooth gap. The monitoring device could then erroneously conclude that a fault has occurred. To avoid a false alarm in such a case, it is advantageous to detect whether the vehicle has been moved between two activations of the parking lock and to take this information into account when detecting faults.

[0035] Brief description of the drawings

[0036] Possible embodiments of the invention are explained below with reference to the accompanying figures. The drawing shows:

[0037] Figure 1 shows a vehicle with a parking lock device according to the invention,

[0038] Figure 2a shows the parking lock device from Figure 1 in the neutral position of the locking element before activation.

[0039] Figure 2b shows the parking lock device when activated in the second rotation position ToG, Figure 2c shows the parking lock device when activated in the first rotation position ToT,

[0040] Figure 3 shows a diagram with operating value curves that are assigned to a first characteristic operating value curve 11 of the electric motor when the parking lock device is activated in the first rotational position ToT, and with operating value curves that are assigned to a second characteristic operating value curve I2 of the electric motor when the parking lock device is activated in the second rotational position ToG,

[0041] Figure 4 shows a diagram with operating value curves that are assigned to a second characteristic operating value curve I2 of the electric motor when the parking lock device is activated in the second rotation position ToG, as well as with operating value curves I2d in the event of a fault, which are also assigned to the second characteristic operating value curve I2 of the electric motor.

[0042] Embodiments of the invention

[0043] Figure 1 shows an embodiment of a parking lock device 1 according to the invention, which is arranged in a vehicle 100, in particular an electrically powered motor vehicle. The parking lock device 1 comprises a parking lock wheel 2 that can be coupled to an output of the vehicle 100, a pawl 3, an actuating mechanism 4, an electric motor 5, and a monitoring device 10. The parking lock wheel 2 has teeth 2a and tooth gaps 2b distributed around its circumference, in particular teeth 2a and tooth gaps 2b that are evenly distributed. In the present embodiment, there are eight teeth 2a, in particular of the same tooth width, and eight tooth gaps 2b, each with the same gap width. The pawl 3 is rotatably mounted about a pivot bearing 33 and is pressed, for example, by a coil spring (not shown) against a plunger 42, which in turn is supported against a stationary cam section 44.The plunger 42 can have a conical outer wall.

[0044] The actuating mechanism 4, for example, has a rod 41 that can be translationally displaced by means of the electric motor 5, wherein the plunger 42 is slidably mounted on the rod 41. The plunger 42 can be supported against the rod 41 by means of a spring 43.

[0045] Figure 2a shows an initial situation in a neutral position of the parking lock mechanism 1. The plunger 42 rests with one end of its conical outer wall against the curved section 44, while an opposite end rests against a cam 32 of the pawl 3. The pawl 3 is pressed against the plunger 42 by a coil spring (not shown). The cam 32 and a locking element 31 of the pawl 3 are arranged at an end of the pawl 3 furthest from the pivot joint 33, with the locking element 31 facing the outer circumference of the parking lock wheel 2. In the neutral position shown in Figure 2a, the parking lock wheel 2 can rotate freely, allowing the teeth 2a and tooth gaps 2b to move past the locking element 31. The locking element 31 does not abut any teeth 2a.

[0046] Figure 2b, which corresponds to the representation in Figure 1, shows the position immediately after activation of the parking lock device 1. The parking lock device 1 was initially actuated in the second rotational position ToG (ToG = "tooth over ground") of the parking lock wheel 2, in which the locking element 31 was opposite a tooth gap 2b at the time of activation. Activation of the parking lock device 1 drove the actuating mechanism 4 by means of the electric motor 5, thereby moving the rod 41 translationally to the left in Figure 2b. This caused the plunger 42 to move along the cam section 44 and be pressed against the cam 33, so that the pawl 3 was pivoted around the pivot bearing 33 towards the parking lock wheel 2. Since the locking element 31 can engage directly in a tooth gap 2b in the second rotational position, the final position shown in Figure 2b results. The spring 43 was not tensioned or only slightly tensioned.The end position in Figures 1 and 2b represents a locking position in which the locking element 31 of the pawl 3 engages in a tooth gap 2b of the parking lock wheel 2 to block the parking lock wheel 2 and prevent the vehicle 100 from rolling away. Figure 2c shows another position immediately after activation of the parking lock device 1. Here, the parking lock device 1 was initially actuated in a first rotational position ToT (ToT = "tooth over tooth") of the parking lock wheel 2, in which the locking element 31 initially faces a tooth 2a. By activating the actuating mechanism 4, the plunger 42 was also moved along the cam section 44 and pressed against the cam 33, so that the pawl 3 was pivoted towards the parking lock wheel 2. Since the locking element 31 cannot engage directly in a tooth gap 2b in the first rotational position, it is pressed against a tooth 2a.Due to the further force applied by the actuating mechanism 4, the rod 41 moves further to the left, pushing it through the plunger 42 and tensioning the spring 43. The tension of the spring 43 acts on the plunger 42 and presses it against the pawl 3, which engages the locking element 31 against the adjacent tooth 2a. If the parking lock wheel 2 now rotates a small angle further due to the vehicle rolling slightly, the locking element 31, actuated by the spring 43, can engage in the next tooth gap 2b. The plunger 42 then moves into its end position on the rod 41, the spring 43 is released, and the end position shown in Figure 2b is again achieved.

[0047] Actuation of the parking lock device 1 in the first rotary position ToT, as shown in Figure 2c, results in a time-dependent profile of operating values ​​of the electric motor 5. The current can be considered one such operating value. Figure 3 shows a diagram in which the current I is plotted on the ordinate and the time t on the abscissa. Several current profiles recorded when the parking lock device was activated in the first rotary position ToT are shown in the diagram. It can be seen that these profiles all correspond to a first characteristic operating value profile 11 or a first characteristic current profile. In contrast, activation of the parking lock device 1 in the second rotary position ToG results in operating profiles that correspond to a second characteristic operating value profile I2 or a second characteristic current profile.As further illustrated in Figure 1, the parking lock device 1 is associated with an electronic monitoring device 10, which detects the current flow through the electric motor 5. The monitoring device 10 has first detection means 11, which detect whether the first characteristic operating value curve 11 or the second characteristic operating value curve I2 occurs when the electric motor 5 is activated. For this purpose, the first detection means detect the operating value curve and decide, for example, based on a numerical analysis method, pattern recognition, or by means of trained artificial intelligence, whether the currently detected operating value curve is assigned to the first characteristic operating value curve 11 or the second characteristic operating value curve I2.

[0048] The monitoring device 10 has second recording means 12 (for example in the form of a counter) which detect how often the second characteristic operating value curve I2 occurs immediately one after the other in a sequence of multiple activations of the parking lock device 1.

[0049] Furthermore, the monitoring device 10 comprises evaluation means 13 which, depending on a number n of immediately successive second characteristic operating value curves I2 detected by the second detection means 12, conclude that a fault has occurred and output a corresponding fault signal. The monitoring device 10 can include a warning device 14 which, depending on the occurrence of the fault signal, generates an alarm signal or initiates an emergency measure.

[0050] In the event of a malfunction of the parking lock device 1, for example, a breakage of the rod 41 or the plunger 42, activation of the parking lock device causes current to flow to the electric motor and actuation of the defective actuating mechanism 4. In this case, actuation of the parking lock device 1 leads to a temporal profile of operating values ​​of the electric motor 5, for example, a current profile I2d, which corresponds to the second characteristic operating value profile I2 or the second characteristic current profile, as shown in Figure 4. Therefore, the second characteristic operating value profile I2 occurs more frequently in the event of a malfunction than with an intact parking lock device. A probabilistic analysis can therefore be used to infer the occurrence of a malfunction.

[0051] In Figure 1, the angle p Gapassigned to an angular segment which, viewed in the circumferential direction of the parking lock wheel e 2, is formed by a tooth 2a and a tooth gap 2b. The angle p Gap specifies an angular measurement which, in a state where the locking element engages in a tooth gap, corresponds to a residual air gap between the locking element and the adjacent flanks of neighboring teeth. p Gap In this case, the angle is 9°. The number of teeth, N Teeth, is known and is 8 in this example. A probability PTOG, which indicates whether the second rotational position ToG is present upon a single activation of the parking lock device 1, can therefore be derived from the relationship: P ToG = pca P / pseg = p Gap N T eeth / 3Q0° = 0.2 can be calculated. A probability value representing this probability PTOG can, for example, be stored in a memory 15 of the monitoring device 10.

[0052] The evaluation means 13 calculate an error probability value PError(n), which represents the probability of an error of the parking lock device 1, for example from the number n of the second characteristic operating value curves I2 that occurred immediately one after the other and from the probability value PTOG, which represents the probability, stored in the memory 15 according to the relationship P E rror n) = 1 - P ToG (n). P-roG(n) can be calculated by determining the probability value representing the probability PTOG according to the relationship

[0053] Pi-oc n) = (PT 0G ) n is multiplied n times with itself, where n is the recorded number of immediately consecutive second characteristic operating value curves transmitted by the second recognition means 12.

[0054] As can be seen in Figure 1, the monitoring device 10 can have third detection means 17, which acquire information B about whether the vehicle 100 is moving. This information B can, for example, be detected by a higher-level system of the vehicle 100 and transmitted to the monitoring device 10. The evaluation means 13 can be configured to conclude that a fault exists only if the vehicle 100 was moved between each of the immediately consecutive second characteristic operating curves I2, depending on the number n of consecutive second characteristic operating curves I2 detected by the second detection means 12 and depending on the information B acquired by the third detection means 17. If the vehicle 100 was not moved, no fault is concluded.This measure can advantageously prevent a false alarm if the vehicle 100 is stationary and the parking lock device 1 is activated several times in succession. The evaluation means can compare the error probability value PError(n) with a threshold value and, depending on the comparison, conclude that an error has occurred and cause the warning device 14 to generate an alarm signal or initiate an emergency measure.

Claims

Claims 1. Parking lock device (1) comprising a parking lock wheel (2) that can be coupled to a vehicle output, a pawl (3), an actuating mechanism (4) and an electric motor (5), wherein the parking lock wheel (2) has teeth (2a) and tooth gaps (2b) distributed around its circumference, wherein, upon activation of the parking lock device (1), the actuating mechanism (4) can be actuated by means of the electric motor (5) to move the pawl (3) into a locking position, wherein in the locking position a locking element (31) of the pawl (3) engages in a tooth gap (2b) of the parking lock wheel (2) to block the parking lock wheel (2), wherein, upon activation of the parking lock device (1), the parking lock wheel (2) can be in either a first rotational position (ToT) or a second rotational position (ToG),wherein the locking element (31) is opposite a tooth (2a) in the first rotational position (ToT) and a tooth gap (2b) in the second rotational position (ToG), wherein a first characteristic operating value profile (11) of the electric motor (5) is associated with activation of the parking lock device (1) in the first rotational position (ToT) and wherein a second characteristic operating value profile (I2) of the electric motor (2) is associated with activation of the parking lock device (1) at least in the second rotational position (ToG), characterized in that an electronic monitoring device (10) is associated with the parking lock device (1), wherein the monitoring device (10) has first detection means (11) which detect whether the first characteristic operating value profile (11) or the second characteristic operating value profile (I2) occurs when the electric motor (5) is activated,wherein the monitoring device (10) has second detection means (12) which detect how often the second characteristic operating value curve (I2) has occurred immediately one after the other in a sequence of multiple activations of the parking lock device (1), wherein the monitoring device (10) has evaluation means (13) wherein the evaluation means (13) infer a fault depending on a number n of immediately successive second characteristic operating value curves (I2) detected by the second detection means (12) and output a corresponding fault signal.

2. Parking lock device according to claim 1, characterized in that the actuating mechanism (4) has a rod (41) which can be moved by means of the electric motor (5), wherein a plunger (42) is slidably mounted on the rod, wherein the plunger (42) is supported against the rod (41) by means of a spring (43), wherein the plunger (42) is pressed against the locking pawl (3) when the parking lock device (1) is activated in order to move the locking pawl (3) into the locking position.

3. Parking lock device according to claim 1 or 2, characterized in that a probability PTOG of whether the second rotational position (ToG) is present upon a single activation of the parking lock device (1) is derived from the relationship PTOG = <P Gap N Teeth / 60° results in Nreeth the number of teeth (2a) of the parking lock wheel (2) is and <p Gapan angular measure which, in a state in which the locking element (31) engages in a tooth gap (2b), is assigned to a residual air gap between the locking element (31) and the adjacent flanks of neighboring teeth (2a), and that a probability value representing this probability PTOG is stored in a memory (15) of the electronic monitoring device (10), wherein the evaluation means, depending on the value representing the probability PTOG stored in the memory (15), infer an error and output a corresponding error signal.

4. Parking lock device according to claim 3, characterized in that the evaluation means (13) calculate an error probability value PError(n), which represents the probability of an error of the parking lock device, from the number n of the second characteristic operating value profiles (I2) that occurred immediately one after the other and from the probability value representing the probability PTOG, which is detected by the second detection means (12).

5. Parking barrier device according to claim 4, characterized in that the evaluation means (13) compare the error probability value PError(n) with a threshold value and infer an error depending on the comparison.

6. Parking barrier device according to claim 4, characterized in that the evaluation means (13) derive the error probability value PError(n) from the relationship P Error ) = 1 - PTOG( L) calculate, where P-roG(n) is calculated from the fact that the value is the probability PT O G represents the probability value according to the relationship Procin) = (PTOGY 1 is copied n times with itself, whereby n is the recorded number of second characteristic operating value curves that occurred immediately one after the other (12).

7. Parking lock device according to one of claims 1 to 6, characterized in that the monitoring device (10) has a warning device (14) which generates an alarm signal or initiates an emergency measure depending on the occurrence of the fault signal.

8. Vehicle (100) with a parking lock device (1) according to one of claims 1 to 7, characterized in that the monitoring device (10) has third detection means (17) which detect information (B) about whether the vehicle (100) is being moved, and that the evaluation means (13) are designed to conclude, depending on the number n of immediately consecutive second characteristic operating value profiles (I2) detected by the second detection means (12) and depending on the information (B) detected by the third detection means (17), that there is a fault only if the vehicle (100) was moved between each of the immediately consecutive second characteristic operating profiles (I2).

9. Method for monitoring a parking lock device (1), wherein the parking lock device (1) comprises a parking lock wheel (2) that can be coupled to a drive of a vehicle, a pawl (3), an actuating mechanism (4), and an electric motor (5), wherein the parking lock wheel (2) has teeth (2a) and tooth gaps (2b) distributed around its circumference, wherein, upon activation of the parking lock device (10), the actuating mechanism (4) can be actuated by means of the electric motor (5) to move the pawl (3) into a locking position, wherein, in the locking position, a locking element (31) of the pawl engages in a tooth gap (2b) of the parking lock wheel (2) to block the parking lock wheel (2), wherein, upon activation of the parking lock device (1), the parking lock wheel (2) can be in either a first rotational position (ToT) or a second rotational position (ToG).wherein the locking element (31) is opposite a tooth (2a) in the first rotational position (ToT) and a tooth gap (2b) in the second rotational position (ToG), wherein a first characteristic operating value profile (11) of the electric motor is associated with an activation of the parking lock device (1) in the first rotational position (ToT) and wherein a second characteristic operating value profile of the electric motor (5) is associated with at least one activation of the parking lock device (1) in the second rotational position (ToG), characterized in that an electronic monitoring device (10) detects whether the first characteristic operating value profile (11) or the second characteristic operating value profile (12) has occurred and is recognized when the electric motor (5) is activated.how often, in a sequence of multiple activations of the parking lock device (1), the second characteristic operating value curve (I2) has occurred immediately one after the other, and depending on a recorded number n of the immediately consecutive second characteristic operating value curves (I2), a fault is inferred and a corresponding fault signal is output.

10. Method according to claim 9, characterized in that a probability PTOG of whether the second rotation position (ToG) is present upon a single activation of the parking lock device (1) is derived from the relationship PTOG = <P Gap N Teeth / 60° results in Nreeth the number of teeth (2a) of the parking lock wheel (2) is and p Gap specifies an angular measure which, in a state in which the locking element (31) engages in a tooth gap (2b), is assigned to a residual air gap between the locking element (31) and the adjacent flanks of neighboring teeth (2a), and that the probability PT O G representing a probability value is stored in a memory (15) of the electronic monitoring device (10), and depending on the probability value representing the probability PTOG stored in the memory (15), a conclusion is drawn about an error and a corresponding error signal is output.

11. Method according to claim 10, characterized in that an error probability value PError(n), which represents the probability of an error of the parking lock device (1), is calculated from the recorded number n of the second characteristic operating value profiles (11) that occurred immediately one after the other and from the probability value representing the probability PTOG.

12. Method according to claim 11, characterized in that the error probability value PError(n) is compared with a threshold value and a conclusion is drawn about an error depending on the comparison.

13. Method according to claim 11, characterized in that the error probability value PError(n) is derived from the relationship P Error ) = 1 - PTOG( L) is calculated, where P-roG(n) is calculated by determining the probability PTOG representing the probability value according to the relationship Procin) = (PTOGY 1 is copied n times with itself, whereby n is the recorded number of second characteristic operating value curves that occurred immediately one after the other (12).

14. Method according to one of claims 9 to 13, characterized in that, depending on the occurrence of the fault signal, an alarm signal is generated or an emergency measure is initiated.

15. Method for monitoring a parking lock device (1) according to one of claims 9 to 14 in a vehicle (100), characterized in that information (B) about whether the vehicle (100) is being moved is recorded by means of the monitoring device (10), and that, depending on the recorded number n of immediately successive second characteristic operating value profiles (12) and depending on the recorded information (B), a fault is only inferred if the vehicle (100) was moved between the immediately successive second characteristic operating profiles (I2).

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