Method for operating an automatic transmission device

Abstract

The invention relates to a method for operating an automatic transmission device (10), preferably for ascertaining a suitable starting speed during a reverse drive of a motor vehicle (100). The invention additionally relates to a controller (16) for controlling an automatic transmission device (10) and to a motor vehicle (100) having a controller (16) for controlling an automatic transmission device (10). The method has the steps of detecting a drive direction change request (12), selecting a starting speed from a plurality of driving speeds of the automatic transmission device (10), preferably a specified plurality of driving speeds, wherein the process of selecting the starting speed is carried out on the basis of at least one vehicle characteristic (14) when the drive direction change request (12) is detected, and setting the selected starting speed on the automatic transmission device (10).

Description

[0001] Method for operating an automatic transmission device

[0002] Description

[0003] The invention relates to a method for operating an automatic transmission. The invention further relates to a control device for controlling an automatic transmission and a motor vehicle having a control device for controlling an automatic transmission.

[0004] In automatic transmissions known from practice, a fixed gear is typically commanded or selected as the starting gear when changing direction. With a central drive currently available with four gears (e.g. Common Central Drive CCD), second gear is used for starting in the forward direction (selector lever position to "Drive" or "D") due to the relatively high torque available in most applications. Furthermore, there is no logic for calculating the correct starting gear when changing direction from forward to reverse, for example. Instead, the vehicle starts off in the same (constant) gear, e.g. first gear. This means that, for example, when maneuvering with multiple changes of direction, when changing direction from forward to reverse (selector lever position to "Rear" or"R") a shift from second gear to first gear is commanded (or when changing from "R" to "D" a shift from first gear to second gear). These shifts are unnecessary in many driving situations, as the tractive force or torque would be sufficient in both "D" and "R" in second gear. In addition, shifts are uncomfortable, lead to jerking of the cabin, take time, are acoustically negative and cause unnecessary actuation cycles for gear adjustment. Furthermore, energy (e.g. mechanical or electrical energy) is consumed for each gear change for the necessary speed synchronization.

[0005] The invention is therefore based on the object of providing an improved method for operating an automatic transmission of a motor vehicle. It is preferably an object of the invention to provide a solution by means of which unnecessary gear shifting operations when changing direction of the motor vehicle are avoided and the driving comfort, the service life of the automatic transmission, and the efficiency of the automatic transmission are improved or increased. According to one aspect, a method is provided for the preferably automated operation of an automatic transmission of a motor vehicle, e.g., for determining and preferably for setting (e.g., commanding, engaging, and / or activating) a suitable starting gear when the motor vehicle is reversing.

[0006] The procedure comprises the following steps:

[0007] A detection of a change of direction request.

[0008] Selecting a starting gear from a (e.g., predetermined) plurality (e.g., a plurality) of gears of the automatic transmission. The selection of the starting gear is performed depending on at least one vehicle characteristic, preferably when the direction change request has been appropriately detected.

[0009] Setting (e.g. commanding, engaging and / or activating) the selected starting gear on the automatic transmission device.

[0010] One advantage may be that unnecessary gear shifts are avoided when changing direction. In particular, the method can enable starting in the same (e.g., lower, lowest, second-lowest, or third-lowest) gear of the automatic transmission when changing direction from forward travel in a gear (e.g., lower, lowest, or second-lowest, or third-lowest) to reverse travel. Furthermore, a method or a method implemented as calculation logic can be provided that calculates the appropriate reverse gear for the situation and compares it with the engaged forward gear to avoid unnecessary gear shifts when changing direction.The method can adapt and expand the known methods to find the correct starting gear for each situation, increase comfort for the driver, accelerate the change of direction, reduce wear on the gear adjustment and reduce energy consumption.

[0011] The change of direction request can be triggered, for example, by manually actuating a gear selector lever (e.g., from “D” to “R” or from “R” to “D,” preferably via a neutral position “N”). The change of direction request is preferably an electronic signal. The change of direction request is preferably detected electronically, e.g., by tapping a corresponding electronic signal from a control unit of the automatic transmission. The plurality of gears can, for example, form a set of gears. The plurality of gears can comprise all gears of the automatic transmission or only a portion of all gears of the automatic transmission. For example, it is conceivable that a subset of all gears of the automatic transmission is predetermined, from which a starting gear is selected.

[0012] The automatic transmission device can, for example, comprise a torque converter automatic transmission or an automated manual transmission or a dual-clutch transmission.

[0013] The method can, for example, be implemented in a control unit. It is then fundamentally conceivable that, preferably depending on the control unit architecture, a calculation of the starting gear takes place continuously in the background, preferably before a change of direction request is detected, depending on the at least one vehicle characteristic. Furthermore, selecting the starting gear can, for example, involve accessing the currently available value of the starting gear, which is continuously calculated based on the at least one vehicle characteristic. This access can preferably be performed once the change of direction request has been detected.

[0014] According to one exemplary embodiment, the at least one vehicle characteristic can comprise a gear selected on the automatic transmission before the direction change request was detected. In other words, when selecting the starting gear, the gear selected on the automatic transmission before the direction change request was detected can be taken into account. Preferably, the gear selected on the automatic transmission before the direction change request was detected is, for example, a lower gear or, for example, the lowest gear or, for example, the second-lowest gear or, for example, the third-lowest gear of the plurality of gears. This can advantageously result in a gear change being carried out or avoided depending on the situation, taking into account the gear already selected or engaged.

[0015] According to one exemplary embodiment, the motor vehicle can comprise a motor, e.g., an electric motor, that is drivingly connected (e.g., operatively connected or drive-connected) to the automatic transmission device. The electric motor can, for example, be a rotating electric machine. The motor (e.g., the electric motor) is preferably drivingly connected to the automatic transmission device without a clutch device. Alternatively or additionally, the selected starting gear can correspond to the gear selected on the automatic transmission device before the direction change request was detected. For example, it is conceivable that, before a direction change from forward to reverse, a gear (e.g., a lower or lowest or second-lowest or third-lowest) of the plurality of gears was selected (e.g., engaged).According to the method, after the request to change direction has been detected, the same gear—for example, the lower or, for example, lowest or, for example, second-lowest or, for example, third-lowest—of the plurality of gears can be selected as the starting gear. This avoids a gearshift, which can have a beneficial effect on driving comfort, shifting time, and / or wear on the automatic transmission. This can be particularly advantageous if the motor vehicle includes an electric motor, since with electric motors, the same gears can typically be used for forward and reverse travel, e.g., if the direction of rotation of the electric motor is inverted.

[0016] In principle, however, the procedure can be applied to all vehicles with automated multi-speed drive (conventional and electric drives).

[0017] According to one embodiment, the plurality of gears can comprise at least two (e.g. three or four) gears with different gear ratios. Preferably, the plurality of gears consists of several, e.g. exactly four, gears with different gear ratios. The selected starting gear can, for example, be a lower or, for example, lowest or, for example, second-lowest or, for example, third-lowest gear of the plurality of gears. In automatic transmission systems with a comparatively high number of gears, the selected starting gear can, however, also be, for example, a fourth-lowest or fifth-lowest or sixth-lowest or seventh-lowest or eighth-lowest (etc.) gear of the plurality of gears. This advantageously makes it possible to select the gear as the starting gear in which, for example, a comparatively high torque ora comparatively high tractive force is available and / or the greatest driving comfort can be achieved and / or which best suits the current driving situation.

[0018] According to one exemplary embodiment, the at least one vehicle characteristic variable can comprise a driving resistance of the motor vehicle. The driving resistance is preferably composed of several resistances, such as a starting resistance, a rolling resistance, and / or a mass inertia of the motor vehicle. It is conceivable that, if the driving resistance lies above a driving resistance limit value, a lower gear, or, for example, the lowest gear, or, for example, the second-lowest gear, or, for example, the third-lowest gear of the plurality of gears is selected. It is also conceivable that, if the driving resistance lies below a driving resistance limit value, a higher gear, or, for example, the highest gear of the plurality of gears is selected.

[0019] According to one embodiment, the method may further comprise determining the driving resistance from a total motor vehicle mass, a total trailer mass, an inclination of the motor vehicle (e.g., on an incline of a slope), an orientation of the motor vehicle (e.g., downhill or uphill), a ratio of a driving gear of the automatic transmission device, a number of axles of the motor vehicle, and / or a number of wheels of the motor vehicle.

[0020] It is conceivable that the driving resistance is determined, for example, by means of sensors and transmitted, preferably wirelessly, to the motor vehicle (e.g. as an electrical signal).

[0021] According to one exemplary embodiment, the at least one vehicle characteristic can include a current steering angle of the motor vehicle. The steering angle is preferably the average wheel steering angle.

[0022] According to one exemplary embodiment, the plurality of gears can comprise a plurality of gears with different gear ratios. The selected starting gear can be, for example, a lower or, for example, lowest or, for example, second-lowest or, for example, third-lowest gear of the plurality of gears if the current steering angle is greater than a predetermined steering angle limit. The selected starting gear can be, for example, a higher or highest gear of the plurality of gears if the current steering angle is smaller than a predetermined steering angle limit. This can advantageously result in a gear being selected with a comparatively large steering angle in which sufficient torque or tractive force is available for the starting process. This can be particularly advantageous if the motor vehicle has a trailer attached.When reversing, the steering angle may increase the articulation angle between the motor vehicle and the trailer, which may increase driving resistance. It may then be advantageous to select a comparatively low gear as the starting gear when changing direction from forward to reverse in order to be able to provide the required torque and / or tractive force. According to one exemplary embodiment, the change of direction request may indicate (e.g., signal and / or display) a change of direction from forward to reverse. However, it is also conceivable for the change of direction request to indicate (e.g., signal and / or display) a change of direction from reversing to forward.

[0023] According to one exemplary embodiment, the at least one vehicle characteristic can comprise a trailer characteristic. The trailer characteristic can indicate whether a trailer is attached (e.g., coupled) to the motor vehicle. The trailer characteristic can be taken into account (e.g., automatically) as the at least one vehicle characteristic when the trailer is coupled. It is conceivable that a starting gear with a comparatively high gear ratio (e.g., a lower or lowest or second-lowest or third-lowest gear of the plurality of gears) is then selected. This can be advantageous due to the comparatively high required torque and / or the comparatively high required tractive force.

[0024] However, it is also conceivable that the at least one vehicle characteristic comprises a selected driving program of the motor vehicle (e.g., a sport and / or performance mode, fuel-saving or eco mode, and / or trailer mode). For example, it is conceivable that in a mode in which fuel is to be saved, a lower or, for example, lowest or, for example, second-lowest or, for example, third-lowest gear of the plurality of driving gears is selected. This allows the selected starting gear to be advantageously adapted to the power requirements of the respective driving program.

[0025] It is further conceivable that the at least one vehicle characteristic comprises a measure of the power requirement of at least one power take-off of the automatic transmission and / or the motor vehicle. Preferably, the selected starting gear is, for example, a lower gear or, for example, the lowest gear or, for example, the second-lowest gear or, for example, the third-lowest gear of the plurality of gears when a predetermined power requirement limit is exceeded. This allows the selected starting gear and the power available via this starting gear to be advantageously adapted to the power requirement of the at least one power take-off.

[0026] It is further conceivable that the at least one vehicle characteristic comprises an achievable engine rotational acceleration. Furthermore, it is conceivable that the at least one vehicle characteristic comprises an activated rocking-free function of the motor vehicle. This can be understood, for example, as a special function of the motor vehicle in which (e.g. if the motor vehicle becomes stuck on a surface with a low coefficient of friction or friction value, such as a snow-covered and / or muddy and / or sandy surface) the motor vehicle is to be freed by successive starting maneuvers in opposite directions of travel. In this case, it can be advantageous if the selected starting gear is, for example, a lower or, for example, lowest or, for example, second-lowest or, for example, third-lowest gear of the plurality of gears.

[0027] Furthermore, it is conceivable that the at least one vehicle characteristic includes an activated reversing restriction of the motor vehicle. This can be understood, for example, as a special function of the motor vehicle in which the motor vehicle must not exceed a specific speed limit and / or a specific power limit when reversing, e.g., due to safety regulations. It is then conceivable that, for example, the selected starting gear is a lower gear, or the lowest gear, or the second-lowest gear, or the third-lowest gear of the plurality of gears. In this way, exceeding the specific speed limit and / or the specific power limit can be avoided.

[0028] According to one embodiment, the at least one vehicle characteristic may comprise a plurality of different vehicle characteristics as disclosed herein. The method may include weighting (e.g., forming a weighted average with different weighting factors) the plurality of different vehicle characteristics. The selection of the starting gear may be performed depending on the plurality of weighted vehicle characteristics. Preferably, the driving resistance, as disclosed herein, is a vehicle characteristic with the greatest weighting.

[0029] According to a second aspect, a control device for controlling an automatic transmission of a motor vehicle (and, for example, for executing a method as disclosed herein) is provided. The control device can, for example, be configured to determine and preferably set (e.g., command, engage, and / or activate) a suitable starting gear when reversing the motor vehicle. The control device can, for example, be an integral component of a control unit of the automatic transmission or, for example, a component installed separately therefrom or, for example, only a separately installed component.

[0030] The control device is configured to detect a change of direction request. The change of direction request may be a change of direction request as disclosed herein.

[0031] The control device is further configured to select a starting gear from a plurality of drive gears of the automatic transmission system depending on at least one vehicle characteristic variable when the direction change request has been detected. The vehicle characteristic variable can be a vehicle characteristic variable as disclosed herein.

[0032] The control device is further configured to control the automatic transmission device in such a way that the selected starting gear is set on the automatic transmission device.

[0033] According to one embodiment, the control device is configured to carry out a method as disclosed herein.

[0034] According to a third aspect, a motor vehicle comprising the control device and the automatic transmission device as disclosed herein is provided.

[0035] Preferably, the motor vehicle is a commercial vehicle. In the latter case, the vehicle can be a motor vehicle whose design and equipment are suitable for transporting people, goods, or trailers. For example, the vehicle can be a truck, a bus, and / or a semi-trailer truck that is at least partially electrically powered. The motor vehicle can be at least partially electrically powered.

[0036] In the context of the invention, in particular a method and / or a control device with a determination strategy for setting (e.g. commanding, engaging and / or activating) a suitable starting gear when reversing the motor vehicle is provided.

[0037] The above-described preferred embodiments and features of the invention can be combined with one another as desired. Details and advantages of the invention are described below with reference to the accompanying drawings. They show:

[0038] Figure 1 is a schematic flow diagram of a method according to an embodiment; and

[0039] Figure 2 shows a schematic representation of a motor vehicle (partial representation) according to an embodiment.

[0040] Identical or functionally equivalent elements are designated by the same reference numerals in all figures and are partly not described separately.

[0041] Figure 1 shows a schematic flow diagram of a method according to one embodiment.

[0042] The method for operating an automatic transmission device 10 of a motor vehicle 100 comprises the following steps:

[0043] In a first step S1, a change of direction request 12 is detected.

[0044] In a second step S2, a starting gear is selected from a (e.g., predetermined) plurality of gears of the automatic transmission system 10. The selection of the starting gear is carried out as a function of at least one vehicle characteristic 14 when the direction change request 12 has been detected. If the method is implemented, for example, in a control unit, it is fundamentally also conceivable that, for example, due to the control unit architecture, a calculation of the starting gear as a function of the at least one vehicle characteristic 14 takes place continuously in the background (e.g., before a direction change request 12 is detected). Then, the selection of the starting gear can, for example, comprise recourse to the currently available value of the starting gear continuously calculated as a function of the at least one vehicle characteristic 14, wherein the recourse is carried out when the direction change request 12 has been detected.

[0045] In a third step S3, the selected starting gear is set (e.g., commanded, engaged, and / or activated) on the automatic transmission system 10. The method can be suitable, for example, for determining and preferably setting (e.g., commanding, engaging, and / or activating) a suitable starting gear when the motor vehicle 100 is reversing.

[0046] The plurality (e.g., multiplicity) of gears can, for example, form a set of gears. The plurality of gears can include all gears of the automatic transmission device 10 or only a portion of all gears of the automatic transmission device 10.

[0047] The change of direction request 12 can be triggered, for example, by manually actuating a gear selector lever 18 (see Figure 2) of the motor vehicle 100 (e.g. from “D” to “R” or from “R” to “D”, in each case preferably via a neutral position “N”).

[0048] The at least one vehicle characteristic 14 can comprise one or more, preferably different, variables, which are described below by way of example.

[0049] For example, the at least one vehicle characteristic 14 can comprise a gear set on the automatic transmission 10 before the direction change request 12 is detected. Optionally, the motor vehicle 100 can comprise an electric motor drivingly connected to the automatic transmission 10. Optionally, the selected starting gear can correspond to the gear set on the automatic transmission 10 before the direction change request 12.

[0050] For example, the at least one vehicle characteristic variable 14 can also include a driving resistance of the motor vehicle 100. It is conceivable that the method further comprises determining the driving resistance from a total vehicle mass, a total trailer mass, an inclination of the motor vehicle 100, an orientation of the motor vehicle 100, a gear ratio of the automatic transmission device 10, a number of axles of the motor vehicle 100, and / or a number of wheels of the motor vehicle 100. Furthermore, it is conceivable that the aforementioned variables are determined, for example, by means of sensors and transmitted, preferably wirelessly, to the motor vehicle 100.

[0051] For example, the at least one vehicle characteristic 14 can also include a current steering angle of the motor vehicle 100. The steering angle is preferably the average wheel steering angle. For example, the at least one vehicle characteristic 14 can include a trailer characteristic. The trailer characteristic can indicate whether a trailer is attached to the motor vehicle 100 and / or coupled to the motor vehicle 100.

[0052] However, it is also conceivable that the at least one vehicle characteristic 14 comprises a selected driving program of the motor vehicle 100.

[0053] Furthermore, it is conceivable that the at least one vehicle characteristic 14 comprises a measure of a power requirement of at least one auxiliary drive of the automatic transmission device 10 and / or the motor vehicle 100. Furthermore, it is conceivable that the at least one vehicle characteristic 14 comprises an achievable engine rotational acceleration and / or an activated rocking function of the motor vehicle 100.

[0054] Furthermore, it is conceivable that the at least one vehicle characteristic 14 comprises an activated reversing restriction of the motor vehicle 100.

[0055] For example, the at least one vehicle characteristic 14 may include a plurality of different vehicle characteristic variables 14 as disclosed herein. The method may include weighting the plurality of different vehicle characteristic variables 14. The selection of the starting gear may be performed depending on the plurality of weighted vehicle characteristic variables 14.

[0056] The plurality of gears may comprise at least three (e.g., four) gears with different ratios. The selected starting gear may, for example, be a lower gear or, for example, the lowest gear or, for example, the second-lowest gear or, for example, the third-lowest gear of the plurality of gears.

[0057] The plurality of gears can comprise several gears with different gear ratios. The selected starting gear can be, for example, a lower or, for example, the lowest or, for example, the second-lowest or, for example, the third-lowest gear of the plurality of gears if the current steering angle is greater than a predetermined steering angle limit. The selected starting gear can be a higher or highest gear of the plurality of gears if the current steering angle is less than a predetermined steering angle limit.

[0058] The change of direction request 12 can indicate a change of direction from forward travel of the motor vehicle 100 to reverse travel of the motor vehicle 100. However, it is also conceivable that the change of direction request 12 indicates a change of direction from reverse travel of the motor vehicle 100 to forward travel of the motor vehicle 100.

[0059] The method may, for example, be suitable for determining and preferably setting (e.g. commanding, engaging and / or activating) a suitable starting gear when the motor vehicle is reversing.

[0060] Figure 2 shows a highly schematic representation of a motor vehicle 100 (partial representation) according to one embodiment.

[0061] The motor vehicle 100 has the control device 16 and an automatic transmission device 10.

[0062] The control device 16 is configured to control the automatic transmission device 10 of the motor vehicle 100 (and, for example, to execute a method as disclosed herein). For this purpose, the control device 16 can be in signal communication (e.g., electrical) with the automatic transmission device 10. The method can be implemented in the control device 16, for example, as calculation logic.

[0063] The control device 16 is configured to detect a change of direction request 12.

[0064] Preferably, the change of direction request 12 is an electronic signal. The change of direction request 12 is preferably detected electronically, e.g., by tapping a corresponding electronic signal from a control unit of the automatic transmission device 10.

[0065] For this purpose, the control device 16 can, for example, be in (e.g., electrical) signal communication with a control unit of the automatic transmission 10. For example, it is conceivable for a driver of the motor vehicle 100 to trigger a change of direction request 12 on a selector lever 18 of the automatic transmission 10 by moving the selector lever 18 (e.g., manually) from a "Drive / D" position to a "Rear / R" position or from a "Rear / R" position to a "Drive / D" position (in each case preferably via a neutral position "N"). If the control device 16 detects (e.g., recognizes) a change of direction request 12 in the manner described above, a starting gear is selected from a plurality of gears of the automatic transmission 10.

[0066] The selection is made depending on at least one vehicle characteristic 14 as disclosed herein.

[0067] For example, the at least one vehicle characteristic 14 can include the driving resistance already described. The control device 16 can be configured to determine which driving gear is suitable as a starting gear for the specific driving resistance. For example, characteristic curves or characteristic maps can be stored in the control device 16 for this purpose, from which a starting gear suitable for the driving resistance can be selected. It is also conceivable that, when making a selection depending on the driving resistance, several suitable driving gears are considered, and then a further selection is made depending on another (e.g., weighted) vehicle characteristic 14 as disclosed herein.

[0068] The control device 16 can, for example, be configured to receive the at least one vehicle characteristic 14 from a vehicle interface 20. However, it is also conceivable that the at least one vehicle characteristic 14, preferably several vehicle characteristic 14, are already stored in the control device 16.

[0069] The vehicle interface 20 can, for example, be an interface to at least one on-board computer and / or to at least one CAN bus and / or to another control unit of the motor vehicle 100.

[0070] Preferably, the control device 16 is in signal connection with the selector lever 18, the automatic transmission device 10 and the vehicle interface 20 via electrical lines. However, a wireless signal connection is also conceivable.

[0071] The control device 16 is further configured to control the automatic transmission 10 such that the selected starting gear is set on the automatic transmission 10. For this purpose, the automatic transmission 10 can have actuating elements, such as shift forks and / or brake elements and / or clutch elements and / or locking elements, which are configured to be moved automatically in response to the control by the control device 16 and to set a specific gear (e.g., to command and / or engage and / or activate). The automatic transmission 10 can, for example, comprise a torque converter automatic transmission or an automated manual transmission or a dual-clutch transmission.

[0072] Preferably, the control device 16 is configured to carry out a method as disclosed herein. The control device 16 can be configured, for example, to determine and preferably to set (e.g., command, engage, and / or activate) a suitable starting gear when the motor vehicle 100 is reversing.

[0073] Although the invention has been described with reference to specific embodiments, it will be apparent to one skilled in the art that various changes may be made and equivalents may be substituted without departing from the scope of the

[0074] Invention. Consequently, the invention is not intended to be limited to the disclosed embodiments, but rather to encompass all embodiments falling within the scope of the appended claims. In particular, the invention also claims protection for the subject matter and features of the subclaims, independent of the claims referred to. All ranges herein are to be understood as disclosed in such a way that, as it were, all values ​​falling within the respective range are individually disclosed, e.g., also as preferred, narrower outer limits of the respective range.

[0075] List of reference symbols

[0076] 10 Automatic transmission device

[0077] 12 Change of direction request

[0078] 14 at least one vehicle characteristic 16 control device

[0079] 18 selector lever

[0080] 20 Vehicle interface

[0081] 100 motor vehicles

Claims

Patent claims 1. A method for operating an automatic transmission device (10) of a motor vehicle (100), preferably for determining a suitable starting gear when reversing the motor vehicle (100), comprising: Detecting a change of direction request (12); Selecting a starting gear from a, preferably predetermined, plurality of gears of the automatic transmission device (10), wherein the selection of the starting gear is carried out as a function of at least one vehicle characteristic variable (14), in particular when the change of direction request (12) has been detected; and Setting the selected starting gear on the automatic transmission device (10).

2. Method according to claim 1, wherein the at least one vehicle characteristic (14) comprises a driving gear set on the automatic transmission device (10) before the direction change request (12) is detected.

3. The method according to claim 2, wherein the motor vehicle (100) comprises a motor, preferably an electric motor, which is drivingly connected to the automatic transmission device (10) and / or the selected starting gear corresponds to the driving gear set on the automatic transmission device (10) before the change of direction request (12).

4. Method according to one of the preceding claims, wherein the plurality of driving gears comprises at least two, preferably three or four, driving gears of different gear ratios and the selected starting gear is a lower or lowest or second-lowest or third-lowest driving gear of the plurality of driving gears.

5. Method according to one of the preceding claims, wherein the at least one vehicle characteristic (14) comprises a driving resistance of the motor vehicle (100).

6. The method according to claim 5, comprising determining the driving resistance from a total motor vehicle mass, a total trailer mass, an inclination of the motor vehicle (100), an orientation of the motor vehicle (100), a ratio of a driving gear of the automatic transmission device (10), a number of axles of the motor vehicle (100) and / or a number of wheels of the motor vehicle (100).

7. Method according to one of the preceding claims, wherein the at least one vehicle characteristic (14) comprises a current steering angle of the motor vehicle (100).

8. The method of claim 7, wherein: the plurality of gears comprises a plurality of gears with different gear ratios; and the selected starting gear is a lower or lowest or second-lowest or third-lowest gear of the plurality of gears when the current steering angle is greater than a predetermined steering angle threshold; and / or the selected starting gear is a higher or highest gear of the plurality of gears when the current steering angle is less than a predetermined steering angle threshold.

9. Method according to one of the preceding claims, wherein the change of direction request (12) indicates a change of direction from forward travel of the motor vehicle (100), preferably via a neutral position, to reverse travel of the motor vehicle (100); or indicates a change of direction from reverse travel of the motor vehicle (100), preferably via a neutral position, to forward travel of the motor vehicle (100).

10. The method according to one of the preceding claims, wherein the at least one vehicle characteristic (14): comprises a trailer characteristic value, which preferably indicates whether a trailer is attached to the motor vehicle (100); and / or comprises a selected driving program of the motor vehicle (100); and / or comprises a measure of a power requirement of at least one power take-off of the automatic transmission device (10) and / or of the motor vehicle (100), and / or comprises an achievable engine rotational acceleration; and / or comprises an activated rocking-free function of the motor vehicle (100); and / or comprises an activated reversing restriction of the motor vehicle (100).

11. Method according to one of the preceding claims, wherein the at least one vehicle characteristic (14) comprises a plurality of different vehicle characteristic variables (14) and the method comprises weighting the plurality of different vehicle characteristic variables (14) and the selection of the starting gear is carried out as a function of the plurality of weighted vehicle characteristic variables (14).

12. A control device (16) for controlling an automatic transmission device (10) of a motor vehicle (100), preferably for carrying out a method according to one of the preceding claims and / or for determining a suitable starting gear when the motor vehicle (100) is reversing, which is configured to: detect a change of direction request (12); select a starting gear from a plurality of gears of the automatic transmission device (10) depending on at least one vehicle characteristic variable (14), in particular when the change of direction request (12) has been detected; and control the automatic transmission device (10) such that the selected starting gear is set on the automatic transmission device (10).

13. Control device (16) according to claim 12, which is arranged to carry out a method according to one of claims 1 to 11.

14. Motor vehicle (100), preferably a commercial vehicle, comprising the control device (16) according to claim 12 or 13 and the automatic transmission device (10).

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