Method for learning at least one locking position of locking actuator, computer program, computer program product and vehicle

Abstract

The invention relates to a method for learning at least one locking position of a locking actuator relative to an electrically drivable element (R) to be locked of a vehicle drive train. According to the invention, the locked or locked element (R) is pivoted in the clockwise direction until the locked element (R) abuts against a first stop of the locking element (VE), and then the locked or locked element is pivoted in the counterclockwise direction until the locked element (R) abuts against a second stop of the locking element (VE). In this case, first motorized angle information of the cutout (A) corresponding to the first stop and second motorized angle information of the cutout (A) corresponding to the second stop are detected, and motorized angle information corresponding to the neutral position of the cutout (A) is derived from the two pieces of angle information. The invention further relates to a computer program, to a computer program product, and to a vehicle.

Description

Technical Field

[0001] The invention relates to a method for learning / calibrating at least one locking position of a locking actuator relative to an electrically drivable element to be locked of a drive train of a vehicle.

[0002] The invention further relates to a computer program and a computer program product, respectively implementing the method, and to a vehicle having such a computer program or computer program product. Background Art

[0003] Some parking locks are known in which an electrically actuated lever with so-called detent teeth interacts with a gear of the drive train to lock or block the drive train. For example, publication DE 10 2017 102804 A1 describes such a parking lock with a detent mechanism.

[0004] Some parking locks are also known, whose locking mechanism or locking element can be adjusted or moved linearly along a movement path. For example, publication DE 10 2019 110 384 A1 can be mentioned, which describes such a parking lock with a locking bolt.

[0005] If the vehicle is parked in an inclined position, for example due to a curb, on which the vehicle is parked, for example with only one wheel on the ground, then when the parking lock is locked, stresses occur in the drive train because the vehicle is supported on the parking lock. In this position of the vehicle, a greater unlocking force, which can be applied by the lock actuator, is required to unlock the parking lock than when the vehicle is parked flat. Summary of the Invention

[0006] Therefore the object of the present invention is to improve the unlocking process of this parking lock.In addition the object of the present invention is to improve the locking process of this parking lock.

[0007] This object is achieved by the method as set forth and protected in accordance with claim 1 .

[0008] A method for learning at least one locking position of a locking actuator, also called a parking lock, relative to an electrically drivable element to be locked of a vehicle's drivetrain is proposed. The method comprises the following steps:

[0009] By means of a control unit connected to the locking actuator, a locking element of the locking actuator is caused to execute a stroke movement, in particular along a stroke axis, into a recess of the element to be locked.

[0010] A sensor signal is received by the control unit, which sensor signal represents the locked position of the locking element in the recess,

[0011] The locked or blocked element is pivoted electrically in the clockwise direction by a control unit until the locked element abuts against a first stop of the blocking element and until a definable electrically driven shut-off torque is reached, at which the pivoting is interrupted.

[0012] The control unit receives first electric angle information of the notch corresponding to the first stop portion,

[0013] The locked or blocked element is pivoted electrically in the counterclockwise direction by a control unit until the locked element abuts against a second stop of the blocking element and until a definable electrically driven shut-off torque is reached, at which the pivoting is interrupted.

[0014] The control unit receives the second electric angle information of the notch corresponding to the second stop portion,

[0015] The control unit determines the electric angle information corresponding to the center position of the notch from the first electric angle information and the second electric angle information of the notch.

[0016] A locking position of the locking actuator—also referred to as a locked position—is understood to be one of a plurality of possible positions of the locking element in which, after the locking element has been moved into the recess during a stroke movement, for example, during an axial stroke movement along a stroke axis, the locking element is located in a displaced or disengaged or deflected state in the recess of the element to be locked. These plurality of positions of the locking element are influenced by a mechanical play between the locking element and the element to be locked in the circumferential direction of the locking actuator or the element to be locked, and also by the elasticity of the locking mechanism between the locking element and the element to be locked, which elasticity, due to the load acting on the locking mechanism, produces a corresponding position of the locking element relative to the element to be locked in a stop position in which the element to be locked bears against the locking element under the action of the load.

[0017] The first stop position and the second stop position described above can also be referred to as so-called latching positions of the locking element.

[0018] Knowledge of the center position enables force-optimized or jam-free locking or engaging processes and unlocking or disengaging processes of the locking actuator, in which the force expenditure that can be applied by the locking actuator to actuate the locking element is minimal or as minimal as possible.

[0019] With knowledge of this neutral position, a stuck or stressed drivetrain can be electrically adjusted accordingly due to the aforementioned tilted position of the parked and locked vehicle, so that the locking element can be unlocked in a force-optimized or non-blocking manner. For example, parking situations where a vehicle is parked on a road with an uphill or downhill slope are also conceivable. In this case, the vehicle is also supported by the locking device or parking lock, specifically because the downward force acting on the vehicle down the slope attempts to move the vehicle.

[0020] In addition, the knowledge of the center position enables the locking actuator to be designed to be as small as possible or very compact, thereby saving structural space for the locking actuator. This also simplifies the assembly cost for the locking actuator.

[0021] In addition, the knowledge of the center position allows for greater manufacturing tolerances of components of the drive train, since these manufacturing tolerances can be compensated by learning methods. Therefore, the knowledge of the center position also enables cost savings when manufacturing such components.

[0022] Furthermore, it is proposed to use the thus learned center position of the notch to infer the corresponding center position of the remaining notches of the element to be locked. For example, a tooth gap of a gear to be locked or a shaft section to be locked is considered, in which a correspondingly complementary locking element engages or can engage.

[0023] It is proposed that the learning method be initiated based on vehicle system requirements.

[0024] Additionally or alternatively thereto, the learning method may also be initiated based on a driver's desire.

[0025] Furthermore, a computer program for executing the aforementioned method and a computer program product are proposed, comprising program code means stored on a computer-readable data medium in order to carry out the aforementioned method when the program code means are executed on a computer.

[0026] Furthermore, a vehicle is proposed having a computer program or a computer program product of the aforementioned type.

[0027] A vehicle is to be understood as any type of vehicle or motor vehicle that is electrically operated, but in particular a passenger car and / or commercial vehicle in the form of an electric vehicle or a hybrid vehicle. The vehicle can also be a partially autonomous or fully autonomous vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The invention will be described in detail below with reference to the accompanying drawings. Further advantageous developments of the invention will be found in the dependent claims and the following description of preferred embodiments. For this purpose, the single accompanying drawing schematically shows:

[0029] Figure 1 Different positions of the blocking element relative to the locked, electrically driven element are shown. DETAILED DESCRIPTION

[0030] Here, for simplicity, Figure 1 Three different blocking states I, II, III of a rotor shaft R of an electric motor drive unit for driving a vehicle are illustrated by means of two pentagonal structures.

[0031] The motor drive unit comprises an electric motor, for example, in the form of a permanent magnet synchronous motor or a separately excited synchronous motor, and optionally a switchable reduction gear or step-down gear coupled to the electric motor, which increases the motor torque accordingly. The locking device is mounted on and supported by the housing of the motor drive unit.

[0032] In this case, the locking device has a locking element VE and an electric drive for actuating the locking element VE, which is accommodated in a housing of the locking device.

[0033] In this case, a recess A is provided in or on the rotor shaft R, into which a correspondingly complementarily designed locking element VE engages in order to lock or block the rotor shaft R (see locking states I, II, III).

[0034] In the locking states II, III, both static and dynamic torque loads of the drive train are introduced into the housing of the electric motor drive unit via the locking mechanism shown.

[0035] In this case, the first locking state I describes a so-called center position of the locking element VE relative to the recess A, which is suitable for being detected by the vehicle system.

[0036] For this purpose, the travel movement of the locking element VE is triggered by a control unit or controller, for example, by the control unit of an inverter, which is itself provided by the vehicle's power electronics. This travel movement can be an axial travel movement, that is, a travel movement of the locking element VE along the travel axis in the recess A.

[0037] A sensor monitoring the locking process registers this travel movement and communicates it to the control unit. The control unit thus receives a sensor signal indicating the locked position of the locking element VE in the recess A. The rotor shaft R is thus locked or blocked.

[0038] The locked or blocked rotor shaft R is then caused to pivot in the clockwise direction by the control unit until it abuts against a first stop of the blocking element VE or comes into contact with it, and until a definable electric shut-off torque is reached, at which the pivoting is interrupted (see blocking state II). The shut-off torque of the motor corresponds to the motor's monitorable current consumption, so that the motor is shut off, or the pivoting of the rotor shaft R is interrupted, when a definable current consumption reference value is reached.

[0039] Subsequently, the control unit detects and stores first electric angle information of the gap A corresponding to the first stop portion.

[0040] Subsequently, the control unit causes the rotor shaft R to pivot in the counterclockwise direction until it abuts against the second stop of the locking element VE or comes into contact with the locking element, and until the definable electric shut-off torque is reached, at which the pivoting is interrupted again (see locked state III).

[0041] Subsequently, the second electric angle information of the gap A corresponding to the second stop portion is detected and stored by the control unit.

[0042] The first and second angle information together describe the so-called idle travel, which the rotor shaft R can pass through in its pivoting circumferential direction and ultimately abut against a stop or one of the stops of the locking element VE or come into contact with the latter.

[0043] Finally, the aforementioned median position of the notch A is determined from the first angle information and the second angle information.

[0044] Using so-called rotor (shaft) position sensors, the position or orientation of the rotor of an electric motor, and thus the position or orientation of the rotor shaft R, on which the rotor is arranged, relative to the three phases or poles of the stator of the electric motor, can be precisely determined. Thus, the rotor (shaft) position sensor not only enables effective commutation of the electric motor but also allows the determination of the first and second angle information when the rotor shaft R respectively abuts the stop of the locking element VE.

[0045] The rotor (shaft) position sensor can be designed in the form of an inductively acting signal transmitter or in the form of a Hall sensor, the mode of operation of which is sufficiently known to a person skilled in the art.

[0046] For this purpose, the thus learned or calibrated center position of the notch A can be used to infer the corresponding center position of the remaining notches of the rotor shaft R to be locked. Additionally or alternatively, the center positions of the remaining notches of the rotor shaft R can also be calibrated or learned in a similar manner—or as described above.

[0047] These center positions, so-called ideal positions, or also support points, are stored or stored in a memory of the control unit so that they can be used using software or a computer program to control the rotating shaft or to rotate the rotor shaft.

[0048] The proposed learning method can be initiated based on vehicle system requirements and / or also based on driver expectations.

[0049] The learning method described within the scope of the present disclosure can be combined with various locking mechanisms of the locking actuator. For example, reference is made to German patent application number 10 2021 208 322.6 and German patent application number 10 2021 213737.7, which each describe a parking lock whose locking mechanism or locking element can be adjusted or moved linearly along a motion path.

[0050] The locking mechanism described in these two German patent applications can be replaced by Figure 1 The pentagonal structure shown in FIG is used to simplify the description.

[0051] German patent application number 10 2021 208 322.6 describes a form-locking element in the form of a locking bolt of a locking actuator, which can be moved or driven in a form-locking manner into a recess of a rotatable element to be locked in the drive train during a stroke movement along the stroke axis.

[0052] In contrast, German patent application number 10 2021 213 737.7 describes a form-locking element of a locking actuator having a circumferential internal toothing, wherein the form-locking element can be moved longitudinally relative to a lockable shaft in an axial stroke movement or driven into a shaft section having a correspondingly complementary external toothing.

[0053] The control unit or controller described above comprises a digital microprocessor unit (CPU), a working memory (RAM), and a storage device, all interconnected with a memory system and a bus system. The CPU is designed to execute commands from a program stored in the memory system, detect input signals from a data bus, and send output signals to the data bus. The memory system, which can include various storage media in the form of magnetic, solid, or other non-volatile media, stores a corresponding computer program for implementing the method and its advantageous embodiments. The program can be provided so that it embodies or is capable of executing various aspects of the method described herein, so that the CPU executes the steps of the method and can thereby control the vehicle and the parking lock or locking device.

[0054] To implement the method, a computer program comprising program code means is suitable for executing all steps of the respective arbitrary claim or method claim when the program is executed in a CPU.

[0055] In this case, the computer program can be loaded into the already existing control electronics using simple tools and used to control both the vehicle and the parking lock or locking device.

[0056] For this purpose, a computer program product is provided which contains program code means stored on a computer-readable data medium in order to carry out the method according to any of the claims when the computer program product is executed in a CPU. The computer program product can also be integrated into the control electronics as a retrofit option.

[0057] While exemplary embodiments have been described in the foregoing description, it should be noted that numerous variations are possible. Furthermore, it should be noted that these exemplary embodiments are merely illustrative and are not intended to limit the scope, application, or structure of the present invention in any way. Rather, the foregoing description provides guidance to those skilled in the art for implementing at least one exemplary embodiment, wherein various changes may be made, particularly with respect to the function and arrangement of the components, without departing from the scope of protection provided by the claims and their combination of equivalent features.

Claims

1. A method for learning at least one locking position of a locking actuator relative to an electrically drivable element (R) to be locked of a drive train of a vehicle, wherein: The method comprises the following steps: causing a locking element (VE) of the locking actuator to execute a stroke movement, in particular along a stroke axis, into a recess (A) of the element (R) to be locked, receiving a sensor signal indicating a locked position of the locking element (VE) in the recess (A), The locked element (R) is pivoted electrically in the clockwise direction until it abuts against a first stop of the locking element (VE) and until a definable electrically driven shut-off torque is reached, at which the pivoting is interrupted, receiving first electric angle information of the notch (A) corresponding to the first stopper, The locked element (R) is pivoted electrically in the counterclockwise direction until it abuts against a second stop of the locking element (VE) and until a definable electrically driven shut-off torque is reached, at which the pivoting is interrupted, receiving the second electric angle information of the notch (A) corresponding to the second stopper, The electric angle information corresponding to the middle position of the notch (A) is determined based on the first electric angle information and the second electric angle information of the notch (A).

2. The method according to claim 1, characterized in that The center position of the recess (A) learned in this way is used to infer the corresponding center position of the remaining recesses of the element (R) to be locked.

3. The method according to claim 1 or 2, characterized in that The learning method is initiated based on vehicle system requirements.

4. The method according to any one of the preceding claims, characterized in that The learning method is initiated based on the driver's desire.

5. A computer program for implementing the method according to any one of claims 1 to 4. 6 . A computer program product comprising program code means which are stored on a computer-readable data carrier in order to carry out the method according to claim 1 , when the program code means are executed on a computer.

7. A vehicle having a computer program according to claim 5 or a computer program product according to claim 6.

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