Method for securing a vehicle, computer program, computer program product and vehicle

Abstract

Method for securing a vehicle by means of a parking lock (2), the actuatable locking element (10) of which is moved in a lifting movement along a lifting axis (X - X) into a recess (8) of a rotatable element (6) of the vehicle to be locked in order to lock it, characterized in that the vehicle is moved on the vehicle system side in the locking state of the parking lock (2) until the locking element (10) is brought into contact with the rotatable element (6), so that a torque acting on the locking element (10) is exerted in order to tension the parking lock for the purpose of protecting the parking lock against tampering.

Description

[0001] The invention relates to a method for securing a vehicle, a computer program and a computer program product, each of which represents the method, as well as a vehicle with such a computer program or computer program product.

[0002] Parking locks are known in which an electrically actuated lever with a ratchet tooth interacts with a gear of a drive train to block or lock the drive train. For example, DE 10 2017 102 804 A1 describes such a parking lock with a ratchet mechanism.

[0003] Parking locks are also known from the prior art, with locking elements that can be adjusted or moved linearly along a path of movement. For example, DE 10 2019 110 384 A1 describes such a parking lock with a locking pin.

[0004] One object underlying the invention is to improve the security of a vehicle.

[0005] This object is achieved by a method proposed and protected according to claim 1.

[0006] A method for securing a vehicle is proposed which has a parking lock with an electrically, pneumatically or hydraulically actuatable locking element which is moved in a lifting movement along a lifting axis into a recess of a rotatable element of the vehicle to be locked in order to lock it.

[0007] In the locked state of the parking lock, the vehicle is moved on the vehicle system side to the extent that or until the locking element is brought into contact with the element, so that a torque acting on the locking element is exerted in order to tension the parking lock.

[0008] This tension creates a tamper-proof barrier that significantly complicates unlocking or disengaging. Even if an attempt is made to tamper with the parking lock actuator while it is tensioned, for example, by applying current to the actuator, the force generated by the actuator is insufficient to complete the unlocking process.

[0009] It is proposed that a gear is locked by moving the locking element into a recess in the form of a tooth gap or a hole in the gear.

[0010] Alternatively, it is proposed that a drive shaft is locked by moving the locking element into a recess in the form of a hole in the drive shaft.

[0011] The element to be locked is preferably an element of an electric motor drive train.

[0012] Furthermore, a computer program for carrying out a method of the type described above and a computer program product are proposed, comprising program code means stored on a computer-readable data carrier in order to carry out the method described above when the program code means are executed on a computer.

[0013] Furthermore, a vehicle with such a computer program or such a computer program product is proposed.

[0014] A vehicle is understood to mean any type of vehicle that is powered either by an internal combustion engine and / or preferably by an electric motor, but in particular passenger cars and / or commercial vehicles.

[0015] The invention will be explained in detail below with reference to the figures. Further advantageous developments of the invention will become apparent from the dependent claims and the following description of preferred embodiments. These schematically show: Fig. 1 a proposed parking lock in a perspective view and Fig. 2 a gearbox with such a parking lock.

[0016] Fig. 1 illustrates an electric motor drive train, which as such comprises an electric drive E (electric drive E) or an electric drive unit E. This can be a so-called axle drive unit with an integrated reduction or step-down gear, which amplifies an electric motor torque accordingly.

[0017] Fig. 1 further illustrates a parking lock 2 for locking a drive shaft 6, which is part of the drive train and can be driven by the electric drive E. The parking lock 2 comprises an electrically actuated locking element in the form of a locking bolt 10, which can be moved in a lifting movement along a lifting axis X-X into a recess in the form of a hole 8 in the drive shaft 6 in a form-fitting manner in order to lock the drive shaft 6. The hole 8 can be designed as a through hole or blind hole and can be circular or elongated.

[0018] Fig. 2, however, illustrates a reduction gear G as an integrated component of the aforementioned axle drive unit E, whose electric motor must be imagined to be arranged behind the gear G or concealed by the gear G. This axle drive unit E includes the previously described parking lock 2 for locking a drive shaft 6, which as such can represent the drive shaft of the electric motor.

[0019] Fig. 2 further illustrates three states - marked by a, b, c - of the axle drive unit, which occur until the drive shaft 6 is locked.

[0020] A moving vehicle equipped with such an axle drive unit E is braked into a parking position in which the vehicle is stationary. During braking, the aim is to precisely align the drive shaft 6 relative to the actuator 4 so that the locking bolt 10 can engage positively in the hole 8.

[0021] In state a, the drive shaft 6 is not yet aligned as desired, ie the vehicle must be moved or braked until the desired relative position of the hole 8 with respect to the actuator 4 is reached (state b), in which the vehicle assumes its final parking position so that it can finally be locked (state c).

[0022] The actuator 4 can be imagined as a very compact actuator with, for example, a screw drive, whose locking bolt 10, which is fixed relative to an actuator housing, interacts with an electrically actuated threaded spindle and which moves the locking bolt 10 along the said stroke axis X - X.

[0023] In a further alternative embodiment, the locking bolt 10 engages in a tooth gap of a gear arranged on the drive shaft 6 in order to lock the gear or the drive shaft 6.

[0024] Alternatively, the actuator 4 can also be arranged parallel to a gear axis so that the locking bolt 10 can be moved into the said tooth gap or a hole of a gear or a hole of a perforated disc.

[0025] The proposed parking lock 2 is very compact since it does not require a ratchet lever to lock a gear of a drive train.

[0026] It's also not about being able to decelerate a possibly still-moving vehicle down to a definable speed limit—for example, approximately 5 km / h. Therefore, there's no need to dissipate the corresponding kinetic energy of such a still-moving vehicle. Consequently, actuating the proposed parking lock advantageously requires only a relatively low amount of force. This, in turn, makes for a compact design. This also allows for reduced manufacturing costs.

[0027] An assistance system or driver assistance system of the vehicle includes the parking lock 2 and also control means for controlling the vehicle and the parking lock 2.

[0028] The assistance system can work as follows: Either it brakes the vehicle during deceleration and when it falls below a definable minimum speed - for example, from 0.1 to 2 km / h, in particular from approximately 0.1 to 1 km / h - always in a defined or incremental manner to a standstill, so that the desired relative position of the hole 8 relative to the locking bolt 10 is achieved; or After the vehicle has been braked from a moving state to a standstill and a parking request from the driver or the vehicle system has been detected, it moves the vehicle in a defined or incremental manner until the desired relative position of the hole 8 relative to the locking bolt 10 is reached.

[0029] By determining the position of the rotor of the electric motor of the axle drive unit E in the circumferential direction ΔΦ, the said relative position can also be determined, if necessary also using given gear ratios, depending on which of the shafts of the gearbox G the hole 8 is formed.

[0030] The rotor position or orientation is provided by at least one sensor installed in and / or on the motor, such as a Hall sensor. Additionally or alternatively, current and voltage information from the electric motor can also be used directly to determine the rotor position or orientation.

[0031] In the embodiment of the Fig.2, however, it is advantageous to form the hole 8 on the drive shaft 6, ie on the transmission input side, in order to minimize a torque load on the locking bolt 8 in the event that the vehicle is parked on a slope and a corresponding downhill force exerts a torque acting on the locking bolt 10, which as such tensions the parking lock.

[0032] Another advantage of arranging the parking lock 2 on the transmission input side is that the vehicle needs to be moved less in order to achieve the said relative movement of the locking bolt 8 to the recess 10.

[0033] This is because the transmission input area must be rotated or moved less by the electric motor of the axle drive unit E in order to achieve the said relative position of the locking bolt 8 to the recess 10, assuming a comparable geometry of a shaft to be locked which has the said recess 10.

[0034] In the case of a transmission output-side arrangement of the parking lock 2, the transmission ratio to be taken into account causes a greater movement of the vehicle or a greater rotation of the transmission output area by the electric motor compared to the transmission input area.

[0035] An arrangement on the transmission input side is therefore advantageous with regard to smaller parking spaces, obstacles surrounding the vehicle and / or people.

[0036] To relieve this slope-induced tension, the electric motor of the axle drive unit E is controlled in such a way that it counteracts the slope force and thereby compensates for it, so that the locking bolt 10 is free of tension, or at least virtually free of tension. Only then is the locking bolt 10 moved out of hole 8 to unlock.

[0037] The assistance system only causes the locking bolt 10 to be actuated into its locking position after the vehicle system has detected a parking position in which the vehicle is stationary and the said relative position of the locking bolt 10 to the hole 8 has been reached.

[0038] It is proposed that, upon detection of a parking request from the driver or the vehicle system, the locking element 10 be moved into the recess 8 in a form-fitting manner and the vehicle is thereby locked.

[0039] A parking request from the driver can be registered as such, for example, by actuating an electric parking brake or by placing the selector lever of an automatic transmission in its park position.

[0040] Therefore, detecting the parking position does not require complex sensory detection of the vehicle's surroundings, but rather only requires registering the driver's parking request, as described above. This makes such an assistance system relatively simple and cost-effective to design and implement.

[0041] Furthermore, it is proposed that the vehicle is moved in the locked state of the parking lock 2 and in a plane - in contrast to the previously mentioned case example with the slope - on the vehicle system side until the locking element 10 is brought into contact with the element 6 in order to tension the parking lock 2 and thereby ensure protection against manipulation of the parking lock.

[0042] To release this tension, the electric motor of the axle drive unit E is controlled in such a way that the locking bolt 10 is released from element 6, or the locking bolt 10 lifts off element 6 and is thus released from tension. Only then is the locking bolt 10 moved out of hole 8 to unlock.

[0043] This tensioning can be carried out in conjunction with an activated parking brake, which locks individual wheels of a vehicle.

[0044] As an alternative to the previously described tension-free unlocking, the electric motor of the axle drive unit E can also be controlled in such a way that it executes a so-called rotary trembling movement, through which the locking bolt 10 repeatedly releases from the element 6 for a short time, or the locking bolt 10 repeatedly lifts from the element 6 for a short time, thereby temporarily de-energizing it. This allows the locking bolt 10 to be gradually moved out of the hole 8 by the actuator 4 to unlock.

[0045] The control means of the assistance system can comprise a digital microprocessor unit (CPU) data-connected to a memory system and a bus system, a random access memory (RAM), and a storage device. The CPU is configured to process commands embodied as a program stored in a memory system, to detect input signals from the data bus, and to output output signals to the data bus. The memory system can comprise various storage media in the form of magnetic, solid-state, and other non-volatile media, on which a corresponding computer program for implementing the method and the advantageous embodiments is stored. The program can be designed in such a way that it embodies or is capable of executing the methods described here, so that the CPU can execute the steps of such methods and thus control both the vehicle and the parking lock.

[0046] Suitable for carrying out the method is a computer program which has program code means for carrying out all the steps of any one of the claims when the program is executed in the CPU.

[0047] The computer program can be easily read into existing control electronics and used to control both the vehicle and the parking lock.

[0048] For this purpose, a computer program product is provided with program code means stored on a computer-readable data carrier for carrying out the method according to any of the claims when the program product is executed in the CPU. The computer program product can also be integrated into the control electronics as a retrofit option.

[0049] Although exemplary embodiments are explained in the foregoing description, it should be noted that numerous modifications are possible. Furthermore, it should be noted that the exemplary embodiments are merely examples and are not intended to limit the scope of protection, applications, or structure in any way. Rather, the foregoing description provides the skilled person with a guide for implementing at least one exemplary embodiment, whereby various modifications, particularly with regard to the function and arrangement of the described components, can be made without departing from the scope of protection as it results from the claims and equivalent combinations of features.

Claims

[1] Method for securing a vehicle by means of a parking lock (2), the actuatable locking element (10) of which is moved in a lifting movement along a lifting axis (X - X) into a recess (8) of a rotatable element (6) of the vehicle to be locked in order to lock it, characterized by that the vehicle is moved in the locked state of the parking lock (2) on the vehicle system side until the locking element (10) is brought into contact with the rotatable element (6), so that a torque acting on the locking element (10) is exerted in order to tension the parking lock for the purpose of protecting the parking lock against manipulation. [2] Method according to claim 1, wherein a gear is locked by moving the locking element (10) into a recess (8) in the form of a tooth gap or a hole of the gear. [3] Method according to claim 1, wherein a drive shaft is locked by moving the locking element (10) into a recess (8) in the form of a hole in the drive shaft. [4] Computer program for carrying out a method according to one of claims 1 to 3. [5] A computer program product comprising program code means stored on a computer-readable data carrier for carrying out the method according to any one of claims 1 to 3 when the program code means are executed on a computer. [6] Vehicle with a computer program product according to claim 5. [7] Driver assistance system with control means comprising a computer program product according to claim 5.

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