Method and control device for operating a parking lock system

Abstract

Method for operating a parking lock system, with a parking lock wheel having recesses distributed on the circumference of the parking lock wheel, which recesses are each defined by a leading tooth flank and a trailing tooth flank viewed in the respective direction of rotation of the parking lock wheel, with a parking lock pawl which can be introduced into one of the recesses of the parking lock wheel with an introduction section in order to lock the parking lock wheel, with a parking lock actuator for the parking lock pawl, with a parking lock sensor for detecting the absolute angular position of the parking lock wheel in order to recognize a rattling process, the absolute angular position of the parking lock wheel is detected and compared with a reference angular position, a rattling process of the parking lock pawl is recognized when the respective absolute angular position is located behind the reference angular position viewed in the respective direction of rotation of the parking lock wheel.

Description

Technical Field

[0001] This invention relates to a method for a parking lock system for operating a motor vehicle. The invention also relates to a control device for implementing this method. Background Technology

[0002] It is known in practice that a parking lock system (typically a component of a vehicle's transmission) protects a stationary vehicle from undesirable rolling. Here, the parking lock system provides a mechanical lock to the vehicle's powertrain. This mechanical locking locks the shaft coupled to the driven mechanism of the vehicle, thus locking the driven mechanism and preventing rotation of both the shaft and the driven mechanism, thereby preventing the vehicle from rolling.

[0003] A parking lock system typically includes a parking lock pawl and a parking lock wheel. The parking lock pawl and parking lock wheel cooperate in such a way as to mechanically lock the drivetrain, such that when the parking lock pawl engages with the parking lock wheel (which is connected to a shaft coupled to a driven device of the vehicle), the parking lock system engages and the shaft, and therefore the driven device, is locked.

[0004] A parking lock system typically also includes a parking lock actuator and a parking lock sensor. The parking lock actuator is used to actuate the parking lock pawl to engage or disengage the parking lock. The parking lock sensor detects the status of the parking lock.

[0005] The parking lock system may also have a parking lock latch. The parking lock latch is used to lock and unlock the parking lock actuator. When the parking lock actuator is locked by the parking lock latch, the parking lock pawl cannot be operated.

[0006] DE102018202370A1 and DE102019205608A1 respectively disclose details of the parking lock system for motor vehicles.

[0007] As known from DE102019205608A1, a plurality of recesses are distributed on the periphery of the parking lock wheel of a parking lock system. Teeth are formed between these recesses. Each of these recesses is defined by a front or forward tooth flank viewed in the respective rotational direction of the parking lock wheel and a rear or rear tooth flank viewed in the rotational direction.

[0008] As known from DE1062223A1, the absolute rotational angular position of a rotating component is detected using a sensor in a measurement technique. This detection of the absolute rotational angular position of the rotating component can be used in parking lock systems.

[0009] When the parking lock pawl is actuated to engage the parking lock system, the pawl can only engage the parking lock system by locking into the recess of the parking lock wheel as specified in the guide section, provided that the rotational speed of the parking lock wheel is less than the limit value. If the rotational speed of the parking lock wheel is too high when the parking lock pawl is actuated to engage the parking lock system, a clicking or rattling sound (Ratsch-Vorgang) can occur from the parking lock pawl.

[0010] It is known from DE102015213612A1 and DE102015208594A1 that the parking lock system is monitored for the clicking sound of the parking lock pawl.

[0011] Existing methods for identifying the clicking sound of parking lock pawls in parking lock systems have the drawback of being prone to error. Especially when the powertrain vibrates, a clicking sound may still be detected even if it doesn't actually occur. Therefore, there is a need to improve the reliability of identifying the clicking sound of parking lock pawls in parking lock systems. Summary of the Invention

[0012] Therefore, the objective of this invention is to provide a novel method and control device for operating a parking lock system.

[0013] The task is accomplished by a method according to the invention for operating a parking lock system.

[0014] To identify the clicking sound of the parking lock pawl, the absolute rotational angle of the parking lock wheel is detected and compared with a reference rotational angle. A clicking sound is identified when the corresponding absolute rotational angle is greater than the reference rotational angle. "Greater than" here means that the corresponding absolute rotational angle, viewed along the corresponding rotational direction of the parking lock wheel, is located behind the reference rotational angle.

[0015] The method according to the invention allows for reliable identification of clicking processes in parking lock systems. In particular, it can prevent clicking processes from being detected during powertrain vibrations, even when no actual clicking process exists.

[0016] Preferably, the reference rotation angle position corresponds to the next rotation angle position of the parking lock wheel along the corresponding rotation direction of the parking lock wheel. At this next rotation angle position, the tooth side of the guide section of the parking lock pawl, preferably the front tooth side viewed along the corresponding rotation direction of the parking lock wheel, can abut against the corresponding tooth side of the next recess of the parking lock wheel along the corresponding rotation direction, preferably the rear tooth side viewed along the corresponding rotation direction of the parking lock wheel. This is particularly preferred in order to reliably identify the clicking process.

[0017] Preferably, in order to identify the clicking process of the parking lock pawl in the parking lock system, the following steps are taken: Operate the parking lock pawl of the parking lock system to engage the parking lock system. When the parking lock pawl's guide section can be guided into one of the recesses of the parking lock wheel solely or solely due to the control principle of the parking lock pawl to engage the parking lock system, the first absolute rotation angle position of the parking lock wheel of the parking lock system is detected. Subsequently, at least one second absolute rotation angle position of the parking lock wheel was further detected. The corresponding second absolute rotation angle position of the parking lock wheel is compared with a reference rotation angle position, which, viewed relative to the first absolute rotation angle position along the corresponding rotation direction of the parking lock wheel, corresponds to the next rotation angle position along the corresponding rotation direction of the parking lock wheel. At this next rotation angle position, the forward tooth side of the guide section of the parking lock pawl along the corresponding rotation direction of the parking lock wheel can abut against the rear tooth side of one of the recesses of the parking lock wheel along the corresponding rotation direction of the parking lock wheel. When the corresponding second absolute rotation angle position is greater than the reference rotation angle position, a clicking process of the parking lock pawl is identified. "Greater than" here means that the corresponding second absolute rotation angle position, viewed along the corresponding rotation direction of the parking lock wheel, is located behind the reference rotation angle position.

[0018] This further improvement is preferred in order to reliably identify the clicking process of the parking lock system.

[0019] A control device according to the present invention is also proposed. Attached Figure Description

[0020] Preferred further improvements will be derived from the following description. Embodiments of the invention are described in more detail with reference to the accompanying drawings, but the invention is not limited thereto. Herein: Figure 1 Details of the vehicle's parking lock system are shown; Figure 2 A signal flow diagram illustrating the present invention is shown. Detailed Implementation

[0021] This invention relates to a method for using a parking lock system in a motor vehicle and a control device. Such a parking lock system is typically a component of the motor vehicle's transmission.

[0022] Figure 1 The structural components of the parking lock system 10 are shown schematically, namely the parking lock wheel 11, the parking lock pawl 12, the parking lock actuator 13, and the parking lock sensor 14.

[0023] The parking lock wheel 11 of the parking lock system 10 has a plurality of recesses 16 distributed around its periphery. Each pair of recesses 16 is configured with a tooth 15. The parking lock wheel 10 is rotatable about a rotation axis X, wherein... Figure 1 Arrow 17 illustrates one possible direction of rotation for the parking lock wheel 11. The parking lock wheel 11 can also rotate in the opposite direction.

[0024] Each of the recesses 16 is defined by a tooth flank, specifically by a frontal or forward tooth flank 18 of the corresponding recess 16 when viewed from the front along the corresponding rotation direction 17 of the parking lock wheel 11, and by a rearal or rearward tooth flank 19 of the corresponding recess 16 when viewed from the rear along the corresponding rotation direction 17 of the parking lock wheel 11. Figure 1 In the opposite rotational directions shown, the front tooth flank 18 and the rear tooth flank 19 are interchanged.

[0025] The parking lock pawl 12 works in conjunction with the parking lock wheel 11, wherein, in order to lock the parking lock wheel 11 and thus engage the parking lock system 10, the guide section 20 of the parking lock pawl 12 can be guided into one of the recesses 16 of the parking lock wheel 11.

[0026] The parking lock pawl 12 can be manipulated by the parking lock actuator 13 to control the parking lock pawl 12 so that it can be guided into a recess 16.

[0027] The absolute rotation angle position of the parking lock wheel 11 can be detected by the parking lock sensor 14.

[0028] As already described in detail, recesses 16 defined by toothed flanks 18 and 19 are distributed on the periphery of the parking lock wheel 11. Each of these toothed flanks 18 and 19 of the recesses 16 may be provided with an absolute rotational angle position defined on the periphery of the parking lock wheel 11.

[0029] This is an example in Figure 1 China targets the region along the coast Figure 1 The rotation direction 17 is observed on the tooth side at the rear of the recess 16 or on the rear tooth side 19. Figure 1 The guide section 20 of the parking lock pawl 12 of the parking lock system 10 is guided into the recess.

[0030] Based on the perimeter width of the recess 16, the perimeter width of the guide section 20, and the position of the parking lock pawl 12, for each of the tooth sides 18 and 19, each recess 16 of the parking lock wheel 11 can also be given an absolute rotation angle position in advance according to the corresponding rotation direction of the parking lock wheel 11. At this absolute rotation angle position, one tooth side of the guide section 20 of the parking lock pawl 12 contacts or touches the corresponding tooth side 18 or 19 of the corresponding recess 16 of the parking lock wheel 11 or abuts against the tooth side.

[0031] The present invention now relates to reliably identifying the clicking process of the parking lock pawl 12 on the parking lock wheel 11. In order to identify the clicking process of the parking lock pawl 12, the absolute rotational angle position of the parking lock wheel 11 is detected by means of the parking lock sensor 14, wherein the detected absolute rotational angle position is compared with the reference rotational angle position.

[0032] When the corresponding absolute rotation angle position is greater than the reference rotation angle position, a clicking process of the parking lock pawl 11 is detected. "Greater than" here means that the corresponding absolute rotation angle position is located behind the reference rotation angle position when viewed along the corresponding rotation direction of the parking lock wheel 11.

[0033] Preferably, the reference rotation angle position corresponds to the next rotation angle position of the parking lock wheel 11 when viewed along the corresponding rotation direction. At this next rotation angle position, the tooth side of the guide section 12 of the parking lock pawl 12, that is, the front tooth side when viewed along the corresponding rotation direction of the parking lock wheel 11, can abut against the corresponding tooth side of one of the recesses 16 of the parking lock wheel 11, that is, the rear tooth side when viewed along the corresponding rotation direction of the parking lock wheel 11.

[0034] Next reference Figure 2 The signal flow diagram illustrates other details of the invention. Figure 2 In block 21 of the signal flow diagram, the parking lock pawl 12 is controlled by the parking lock actuator 13 to engage the parking lock system 11.

[0035] In the next step 22, it is checked whether, solely or alone, the guide section 20 of the parking lock pawl can be guided into one of the recesses 16 of the parking lock wheel 11 due to the actuation of the parking lock pawl 12. This is the case when the actuator 13 has fully actuated the parking lock pawl 12, i.e., regardless of the position of the parking lock wheel 11, i.e., even when the guide section 20 contacts the teeth 15 of the parking lock wheel 11.

[0036] If it is determined in block 22 that the parking lock pawl 12 cannot be guided into one of the recesses 16 of the parking lock wheel 11 by its guide section 20 solely or solely due to the actuation of the parking lock pawl 12, then the branch returns to block 22. If it is determined in block 22 that the guide section 20 of the parking lock pawl 12 can, in principle, be guided into one of the recesses 16 of the parking lock wheel 11 solely or solely due to the actuation of the parking lock pawl 12, then the branch proceeds to step 23.

[0037] In step 23, the first absolute rotation angle position of the parking lock wheel 11 is detected.

[0038] The first absolute rotational angle position of the parking lock wheel 11 is the following rotational angle position of the parking lock wheel 11: the rotational angle position occupied by the parking lock wheel when the guide section 20 of the parking lock pawl can be guided into one of the recesses 16 of the parking lock wheel 11 in principle, either alone or solely, by the operation of the parking lock pawl 12, so as to engage the parking lock system 11.

[0039] The first absolute rotation angle position is stored, wherein a reference rotation angle position is determined based on the first absolute rotation angle position and the rotation direction of the parking lock wheel.

[0040] Also in step 23, a reference rotation angle position is determined, wherein the reference rotation angle position relative to the first rotation angle position observed along the corresponding rotation direction of the parking lock wheel 11 corresponds to the next rotation angle position of the parking lock wheel 11 along the corresponding rotation direction of the parking lock wheel 11, at which the forward tooth side of the guide section 20 of the parking lock pawl 12 along the corresponding rotation direction of the parking lock wheel 11 can abut against the corresponding rear tooth side 19 of one of the recesses 16 of the parking lock wheel 11 along the corresponding rotation direction of the parking lock wheel 11.

[0041] Next, in step 24, the parking lock sensor 14 is used to further detect at least one second absolute rotation angle position of the parking lock wheel 11, wherein in subsequent step 25, it is checked whether the corresponding determined second absolute rotation angle position is greater than a reference rotation angle position determined in relation to the first absolute rotation angle position.

[0042] "Greater than" here means that the corresponding second absolute rotation angle position is located behind the reference rotation angle position when viewed along the corresponding rotation direction of the parking lock wheel 11.

[0043] If this is not the case, then the branch from box 25 returns to box 24.

[0044] If it is determined in box 25 that the two determined absolute rotation angle positions are located behind the reference rotation angle position when viewed along the corresponding rotation direction of the parking lock wheel 11, then a branch starts from box 25 to box 26, where the clicking process of the parking lock pawl 12 is then identified in box 26.

[0045] The present invention also relates to a control device for a motor vehicle designed to implement the above-described method in terms of control. The control device according to the invention is preferably a control device for operating the parking lock of a motor vehicle, i.e., for example, a transmission control device of a motor vehicle including a parking lock, or an electronic control device of a motor vehicle including a electrically driven drive axle with a parking lock. The control device according to the invention is designed to detect the absolute rotational angular position of the parking lock wheel by the parking lock sensor 14 and compare it with a reference rotational angular position. When the control device identifies that the corresponding measured absolute rotational angular position, viewed along the corresponding rotational direction of the parking lock wheel 11, is located behind the reference rotational angular position, the control device identifies the presence of a clicking process of the parking lock pawl 12, and more precisely, as described in detail above.

[0046] The control device is preferably an electronic control device, which includes hardware and software components for implementing the method according to the invention. A data interface, belonging to the hardware components, is used to exchange data with structural assemblies involved in implementing the method according to the invention, i.e., to exchange data with, for example, the parking lock sensor 14. Furthermore, the hardware structural assemblies include a processor for data processing and a memory for data storage. Program modules, belonging to the software components, are executed within the control device to implement the method according to the invention.

[0047] Figure Labels

[0048] 10 Parking Lock System

[0049] 11 Parking Lock Wheel

[0050] 12 Parking lock pawl

[0051] 13 Parking lock actuator

[0052] 14 Parking lock sensor

[0053] 15 teeth

[0054] 16 recess

[0055] 17. Direction of rotation

[0056] 18 Tooth flanks

[0057] 19 Tooth flanks

[0058] 20 Import Section

[0059] 21 steps

[0060] 22 steps

[0061] 23 steps

[0062] 24 steps

[0063] 25 steps

[0064] 26 steps

Claims

1. A method for operating a parking lock system (10) integrated with a vehicle transmission, in, The parking lock system (10) has a parking lock wheel (11) having recesses (16) distributed on the periphery of the parking lock wheel (11), which are respectively defined by a front tooth flank (18) and a rear tooth flank (19) viewed along the respective rotation direction (17) of the parking lock wheel (11). The parking lock system (10) includes a parking lock pawl (12) that can be inserted into one of the recesses (16) of the parking lock wheel (11) via an insertion section (20) to lock the shaft coupled to the parking lock wheel (11) and prevent the shaft from rotating. The parking lock system (10) has a parking lock actuator (13) for the parking lock pawl (12). The parking lock system (10) has a parking lock sensor (14) for detecting the absolute rotational angle position of the parking lock wheel (11). The parking lock pawl (12) is operated by the parking lock actuator (13) to engage the parking lock system (10). If the rotation speed of the parking lock wheel is too high when the parking lock pawl is operated to engage the parking lock system, a clicking process of the parking lock pawl may occur. In order to identify the clicking process of the parking lock pawl (12), the absolute rotation angle position of the parking lock wheel (11) is detected and compared with the reference rotation angle position. When the corresponding absolute rotation angle position is located behind the reference rotation angle position when viewed along the corresponding rotation direction of the parking lock wheel (11), the clicking process of the parking lock pawl (12) is identified.

2. The method according to claim 1, characterized in that, The reference rotation angle position corresponds to the next rotation angle position of the parking lock wheel (11) along the corresponding rotation direction of the parking lock wheel (11), at which the tooth side of the guide section (20) of the parking lock pawl (12) can abut against the corresponding tooth side of the next recess (16) of the parking lock wheel along the corresponding rotation direction.

3. The method according to claim 2, characterized in that, The reference rotation angle position corresponds to the next rotation angle position of the parking lock wheel along the corresponding rotation direction, at which the tooth side of the front portion of the guide section (20) viewed along the corresponding rotation direction can abut against the tooth side of the rear portion of the next recess (16) of the parking lock wheel viewed along the corresponding rotation direction.

4. The method according to any one of claims 1 to 3, characterized in that, To identify the clicking process of the parking lock pawl (12) of the parking lock system (10), the following steps are taken: Operate the parking lock pawl (12) to engage the parking lock system (10). When the guide section (20) of the parking lock pawl (12) can, in principle, be guided into one of the recesses (16) of the parking lock wheel (11) solely due to the operation of the parking lock pawl (12), the first absolute rotation angle position of the parking lock wheel (11) is detected. Subsequently, at least one second absolute rotation angle position of the parking lock wheel (11) was further detected. The corresponding second absolute rotation angle position of the parking lock wheel (11) is compared with the reference rotation angle position, which is the next rotation angle position of the parking lock wheel (11) along the corresponding rotation direction when viewed relative to the first absolute rotation angle position. At this next rotation angle position, the tooth side of the lead section (20) of the parking lock pawl (12) that is forward along the corresponding rotation direction of the parking lock wheel (11) can abut against the tooth side of one of the recesses (16) of the parking lock wheel (11) that is backward along the corresponding rotation direction of the parking lock wheel (11). When the corresponding second absolute rotation angle position is located behind the reference rotation angle position when viewed along the corresponding rotation direction of the parking lock wheel (11), the clicking process of the parking lock pawl (12) is identified.

5. A control device for a motor vehicle with a transmission, wherein, The transmission of the motor vehicle has a parking lock system (10). In order to identify the clicking process of the parking lock pawl (12) of the parking lock system (10), the control device is designed to receive the absolute rotation angle position of the parking lock wheel (11) from the parking lock sensor (14) and compare the absolute rotation angle position with the reference rotation angle position. When the control device identifies that the corresponding absolute rotation angle position is located behind the reference rotation angle position when viewed along the corresponding rotation direction of the parking lock wheel (11), the control device identifies the presence of a clicking process of the parking lock pawl (12), and the control device is configured to implement the method according to any one of claims 1 to 4.

6. The control device according to claim 5, characterized in that, This control device is a transmission control device.

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