Method and device for controlling the tensioning between a drive unit and a brake unit of a motor vehicle

Abstract

A description is given of a device for operating a drive unit and a brake unit of a motor vehicle, wherein the device is configured to bring about tensioning between the drive unit and the brake unit while the motor vehicle is travelling, during which tensioning the drive unit sets an effective drive torque other than zero and the brake unit sets an effective brake torque other than zero. The device is furthermore configured to determine that there is a hindrance to the tensioning between the drive unit and the brake unit and, in response to this determination, to cause the tensioning between the drive unit and the brake unit to be reduced or completely eliminated.

Description

[0001] Method and device for controlling the tension between a drive unit and a brake unit of a motor vehicle

[0002] The invention relates to a method and a corresponding device for operating a drive unit and a brake unit of a motor vehicle.

[0003] A motor vehicle may have one or more driver assistance systems, each designed to automatically intervene in the vehicle's longitudinal control, particularly to limit its dynamics, such as acceleration and / or speed. This automatic intervention in longitudinal control can be achieved, for example, by limiting the vehicle's drive torque. Such limitations on the vehicle's dynamics can impair comfort, especially during transitions from a movement against the selected direction of travel to a movement in the selected direction.

[0004] Automatic, limiting intervention in the longitudinal guidance can be conveniently achieved through the coordinated operation of a drive unit to propel the vehicle and a brake unit to decelerate it. The drive unit and the brake unit can be pre-tensioned against each other.

[0005] 24-1739 ABZ EXA 24.09.2024 This document addresses the technical challenge of achieving a particularly reliable clamping between a drive unit and a brake unit of a motor vehicle, especially in connection with an automatic, limiting intervention in the longitudinal guidance of the motor vehicle.

[0006] The problem is solved by each of the independent claims. Advantageous embodiments are described, inter alia, in the dependent claims. It should be noted that additional features of a claim dependent on an independent claim, without the features of the independent claim itself or only in combination with a subset of the features of the independent claim, can constitute a separate invention independent of the combination of all features of the independent claim, which can be made the subject of an independent claim, a divisional application, or a subsequent application. This applies equally to technical teachings described in the description, which can constitute an invention independent of the features of the independent claims.

[0007] According to one aspect, a device for operating a drive unit and a brake unit of a motor vehicle is described. The drive unit can comprise an electric drive motor and / or an internal combustion engine. The brake unit can have one or more (hydraulic) wheel and / or friction brakes.

[0008] The device is designed to create a tension between the drive unit and the brake unit during vehicle travel, such that the effective drive torque from the drive unit is not zero, and the effective brake torque from the brake unit is not zero. The effective drive torque and the effective

[0009] 24-1739 ABZ EXA 24.09.2024 Braking torques typically add up to an effective total torque for moving the motor vehicle (in particular, to effect movement of the motor vehicle). The movement of the motor vehicle can be in the direction of travel selected (via the motor vehicle's transmission) or against the selected direction of travel. The tension between the drive unit and the brake unit can, for example, be used to effect a particularly smooth transition between movement against the selected direction of travel and movement in the selected direction of travel.

[0010] The tension between the drive unit and the brake unit is typically such that the effective drive torque provided by the drive unit and the effective brake torque provided by the brake unit counteract each other. In particular, the sum of the magnitude of the effective drive torque and the magnitude of the effective brake torque can be greater than the magnitude of the total effective torque.

[0011] The device is further configured to determine whether an impediment to the clamping between the drive unit and the brake unit exists. In this context, the device may be configured to identify one or more indicators of the existence of an impediment to the clamping between the drive unit and the brake unit. These one or more indicators may, for example, relate to...

[0012] • the selected gear of the vehicle's transmission, in particular that gear "N" is engaged (and therefore no drive torque should be supplied by the drive unit to accelerate the vehicle from a standstill); and / or

[0013] • the temperature of the brake unit, in particular that the temperature of the brake unit reaches or exceeds a temperature threshold (and thus overheating of the brake unit could occur); and / or

[0014] 24-1739 ABZ EXA 24.09.2024 • the vehicle's speed, in particular that the vehicle's speed reaches or exceeds a speed threshold (e.g. 10 km / h) (and thus there is movement of the motor vehicle outside the near-standstill range, which could lead to overheating of the brake unit).

[0015] It can be determined in a particularly reliable manner, based on one or more indicators, that there is a reason for the tension between the drive unit and the brake unit.

[0016] The device is further configured, in response to the detection of an impediment to the clamping between the drive unit and the brake unit, to reduce or completely eliminate the clamping between the drive unit and the brake unit. In particular, the clamping between the drive unit and the brake unit can be reduced or completely eliminated in such a way that the effective total torque remains unchanged.

[0017] The device can be configured to reduce the effective drive torque provided by the drive unit, in particular to zero, and to increase the effective braking torque provided by the brake unit, in particular in a complementary manner to the effective drive torque. Alternatively, the device can be configured to reduce the effective braking torque provided by the brake unit, in particular to zero, and to increase the effective drive torque provided by the drive unit, in particular in a complementary manner to the effective braking torque. In this way, the tension between the drive unit and the brake unit can be reliably reduced, in particular eliminated.

[0018] By selectively reducing or eliminating the tension between the drive unit and the brake unit, particularly reliable and

[0019] 24-1739 ABZ EXA 24.09.2024 robustly ensures comfortable operation of the motor vehicle in near-standstill areas.

[0020] The device can be configured to eliminate the tension between the drive unit and the brake unit in such a way that the effective total torque for the movement of the vehicle (regardless of the vehicle's direction of travel) is entirely assigned to the effective drive torque when the effective total torque is equal to or greater than zero. The effective total torque thus always acts as a driving force in the direction of the selected gear, i.e., in the selected direction of travel.

[0021] Alternatively or additionally, the device can be configured to eliminate the tension between the drive unit and the brake unit in such a way that when the effective total torque is equal to or less than zero, the effective total torque for the movement of the motor vehicle

[0022] • is fully allocated to the effective braking torque when the motor vehicle is moving in the selected direction of travel; or

[0023] • negated (i.e. with reversed sign) is completely assigned to the effective braking torque when the motor vehicle is moving in the opposite direction to the selected direction of travel.

[0024] The effective total moment therefore always acts against the direction of movement of the vehicle towards standstill.

[0025] This allows for a particularly reliable and comfortable reduction of tension between the drive unit and the brake unit.

[0026] The device can be configured to smoothly reduce or completely eliminate the tension between the drive unit and the brake unit over a transition period, particularly by means of a transition factor. The transition period can be, for example, 0.5 seconds or longer. A smooth transition allows for...

[0027] 24-1739 ABZ EXA 24.09.2024 particularly comfortable reduction of tension between the drive unit and the brake unit is achieved.

[0028] The device can be configured to apply tension during a transition between a first movement of the vehicle against the selected direction of travel and a second movement of the vehicle in the selected direction of travel. The selected direction of travel can be determined by the gear selected by the driver (e.g., forward or reverse). The selected direction of travel for a forward gear can correspond to the forward direction. The selected direction of travel for a reverse gear can correspond to the reverse direction. The selected direction of travel can correspond to a desired direction of travel (by the driver).

[0029] As previously explained, a motor vehicle can have a transmission to effect different (selected) directions of travel. Alternatively or additionally, the different (selected) directions of travel can be effected directly by the motor vehicle's drive unit (e.g., when using an electric motor as the drive unit).

[0030] It can happen that the vehicle (e.g., due to a previous change of direction) initially moves in the opposite direction to the selected direction of travel. For example, a change of direction from an original direction (e.g., reverse) to a new direction (e.g., forward) can occur while the vehicle is still moving in its original direction. The change of direction can be caused, for example, by the driver operating a specific control element (e.g., a gear selector or a button). Such a change of direction can lead to a situation where the

[0031] 24-1739 ABZ EXA 24.09.2024 Motor vehicle initially moved against the selected direction of travel (and thus performs a first movement against the selected direction of travel).

[0032] The drive unit can effect a transition from the first movement (against the selected direction of travel) to a second movement (in the selected direction of travel). As already explained, the drive unit can include at least one electric drive motor and / or an internal combustion engine. The brake unit can include one or more (hydraulic) wheel and / or friction brakes.

[0033] By clamping the drive unit and the brake unit, a particularly comfortable transition from the first movement (against the selected direction of travel) to a second movement (in the selected direction of travel) can be achieved.

[0034] The device can be configured to determine a first effective total torque for the first movement and a second effective total torque for the second movement. The first and second effective total torques can be different. This can be the case, in particular, if the drive torque and / or the braking torque is limited or restricted, with the limitation or restriction being imposed by a driver assistance system of the vehicle. The first effective total torque for the first movement and / or the second effective total torque for the second movement can be designed such that (in particular by the first effective total torque) a predetermined minimum deceleration towards standstill is ensured and / or that (in particular by the second effective total torque) acceleration from standstill is limited.

[0035] The device can be configured to provide a driver-side drive torque requested by the driver of the vehicle and / or a driver-side control signal.

[0036] 24-1739 ABZ EXA 24.09.2024 To determine the driver-requested braking torque of the vehicle. The driver can, for example, depress the accelerator pedal to request a drive torque and / or depress the brake pedal to request a braking torque.

[0037] The first effective total torque for the first movement and / or the second effective total torque for the second movement can then be determined on the basis of the driver's driving torque and / or on the basis of the driver's braking torque (in particular on the basis of the sum of the driver's driving torque and the driver's braking torque).

[0038] The device can be configured to determine a system-side drive torque limit and / or a system-side brake torque limit set by a vehicle assistance system. The first effective total torque for the first movement and / or the second effective total torque for the second movement can then be determined based on the system-side drive torque limit and / or the system-side brake torque limit.

[0039] The device can be configured, in particular, to determine the first effective total torque for the initial movement based on the driver's drive torque (specified by actuating the accelerator pedal) and / or based on the driver's braking torque (specified by actuating the brake pedal), specifically based on the sum of the driver's drive torque and / or the driver's braking torque, without taking into account the system-side drive torque limit and / or the system-side braking torque limit. Thus, during the initial movement, a system-side limit can be disregarded to allow unlimited vehicle dynamics towards a standstill.

[0040] 24-1739 ABZ EXA 24.09.2024 On the other hand, the device may be configured to take into account the system-side drive torque limit and / or the system-side brake torque limit even during the initial movement (against the selected direction of travel). If the sum of the driver-side drive torque and / or the driver-side brake torque does not meet the limiting requirement of the driver assistance system (i.e., the system-side drive torque limit and / or the system-side brake torque limit), the requirement of the driver assistance system may be implemented.

[0041] Furthermore, the device can be configured to determine the second effective total torque for the second movement as the sum of the driver-side drive torque (specified by actuating the accelerator pedal) and the driver-side braking torque (specified by actuating the brake pedal), if this sum is less than the sum of the system-side drive torque limit and the system-side braking torque limit, and / or to determine the second effective total torque for the second movement as the sum of the system-side drive torque limit and the system-side braking torque limit, if this sum is less than the sum of the driver-side drive torque and the driver-side braking torque. In this way, a system-side limit can be taken into account in a precise and convenient manner.

[0042] The device can thus be configured to take into account the system-side drive torque limit and / or the system-side brake torque limit during the second movement (along the selected direction of travel) (regardless of how the first movement was handled). If the sum of the driver-side drive torque and / or the driver-side brake torque does not meet the limiting requirement of the driver assistance system (i.e., the system-side drive torque limit and / or the system-side

[0043] 24-1739 ABZ EXA 24.09.2024 Brake torque limitation) is fulfilled, so it can be ensured that the requirement of the driver assistance system is implemented.

[0044] The device can further be configured to determine the effective driving torque and the effective braking torque on the basis of the first effective total torque and the second effective total torque in such a way that the effective driving torque and the effective braking torque do not change by more than 10%, in particular by more than 5%, (in particular essentially not) during the transition between the first and the second movement.

[0045] The device can be configured to determine the effective drive torque A and the effective braking torque B such that

[0046] • A + B deviates from the first effective total moment by no more than 10%, in particular by no more than 5%; and

[0047] • A - B deviates by no more than 10%, in particular by no more than 5%, from the second effective total moment.

[0048] In a preferred example, the device is configured to determine the effective driving torque A and the effective braking torque B such that

[0049] • the effective driving torque and the effective braking torque do not change in magnitude during the transition between the first and second movements; and

[0050] • A + B equals the first effective total moment; and

[0051] • A - B equals the second effective total moment.

[0052] The effective drive torque and the effective braking torque can be determined in particular by the following:

[0053] • the effective driving torque remains constant during the transition between the first and second movements; and

[0054] • the effective braking torque changes only in sign but not in magnitude during the transition between the first and second movements.

[0055] 24-1739 ABZ EXA 24.09.2024 The effective drive torque can be considered a virtual accelerator pedal torque. In other words, the effective drive torque corresponds to a torque input that corresponds to a specific (virtually executed) deflection of the accelerator pedal. Similarly, the effective braking torque can be considered a virtual brake pedal torque. In other words, the effective braking torque corresponds to a torque input that corresponds to a specific (virtually executed) deflection of the brake pedal.

[0056] Furthermore, the device can be configured to cause the drive unit to provide the effective drive torque and the brake unit to provide the effective braking torque for the transition between the first and second movements.

[0057] The described distribution of the effective total torques during a transition between a first movement (against the selected direction of travel) and a second movement (along the selected direction of travel) allows for a particularly smooth zero crossing of the vehicle's speed. Both the (effective) drive torque (typically provided by an electric motor) and the contact pressure of the one or more friction brakes (hydraulically or electrically operated) can remain constant during the vehicle's zero crossing. Furthermore, even without precise knowledge of the point in time at which the transition between the first and second movements occurs (which may be difficult to determine in special situations such as wheel slippage), it can be ensured that the driver's intended action (i.e.,the driver's drive torque and / or the driver's braking torque) is implemented while adhering to a limiting specification of a driver assistance system.

[0058] It should be noted that this document contains a positive element in the direction of travel. Conversely, a negative element is also present.

[0059] 24-1739 ABZ EXA 24.09.2024 against the selected direction of travel. The letters A and B each indicate the absolute value of the respective moment. A positive vehicle speed corresponds to movement in the selected direction of travel, while a negative vehicle speed corresponds to movement against the selected direction of travel. The vehicle speed thus passes through zero at the transition from the first movement (against the selected direction of travel) to the second movement (in the selected direction of travel).

[0060] The device can be configured to determine whether the motor vehicle is in a state of motion within a predefined transition range between the first and second movements. In particular, it can determine whether the motor vehicle's state of motion is within this transition range based on its speed. The transition range can lie between a (negative) first speed threshold for the first movement and a (positive) second speed threshold for the second movement. The transition range can be specifically limited by these first and second speed thresholds.

[0061] The device can be configured to cause the drive unit to provide the effective drive torque and the brake unit to provide the effective braking torque when the vehicle's state of motion is within the predefined transition range. Furthermore, the device can be configured to cause the drive unit to provide a drive torque that differs from the effective drive torque and the brake unit to provide a braking torque that differs from the effective braking torque when the vehicle's state of motion is outside the predefined transition range.

[0062] 24-1739 ABZ EXA 24.09.2024 The device may, for example, be configured to cause the brake unit to provide the effective total torque when the vehicle performs the first movement and the vehicle's state of motion is not in the transition range. Alternatively or additionally, the device may be configured to cause the drive unit to provide the effective total torque when the vehicle performs the second movement and the vehicle's state of motion is not in the transition range.

[0063] When using an electric machine as a drive unit, the device can be configured to cause the electric machine (operated as a generator) to provide the effective total torque when the vehicle performs the first movement and its state of motion is not in the transition range. Furthermore, the device can be configured to cause the electric machines to provide the effective total torque when the vehicle performs the second movement and its state of motion is not in the transition range.

[0064] Outside the transition range, the (effective) total torque can therefore be provided via the drive unit (in particular via the one or more electric machines of the drive unit) in both the first and the second movement, in order to recover energy during deceleration or because accelerating torques can only be provided by the drive unit.

[0065] By adjusting the distribution of the effective total torque to the respective state of motion of the vehicle, the comfort and efficiency of the vehicle can be further increased. Furthermore, the driver's wishes can be correctly implemented even when the vehicle is near standstill, taking into account the limitations of a driver assistance system.

[0066] 24-1739 ABZ EXA 24.09.2024 According to another aspect, a (road) motor vehicle (in particular a passenger car or a truck or a bus or a motorcycle) is described which includes the device described in this document.

[0067] According to one aspect, a method for operating a drive unit and a brake unit of a motor vehicle is described. The method includes, during the vehicle's operation, inducing a tension between the drive unit and the brake unit, whereby the effective drive torque of the drive unit is reduced to non-zero, and the effective brake torque of the brake unit is reduced to non-zero. Furthermore, the method includes determining that a constraint on the tension between the drive unit and the brake unit exists, and in response to this determination, causing the tension between the drive unit and the brake unit to be reduced or completely eliminated.

[0068] It should be noted that the aspects described in connection with the device, in particular the claims described in connection with the device, are also applicable to the method as corresponding process features.

[0069] Another aspect described is a software (SW) program. The SW program can be configured to run on a processor (e.g., on a vehicle's control unit) and thereby execute the procedure described in this document.

[0070] Another aspect describes a storage medium. This storage medium can include a software program configured to run on a processor and thereby execute the procedure described in this document.

[0071] 24-1739 ABZ EXA 24.09.2024 It should be noted that the methods, devices, and systems described in this document can be used both alone and in combination with other methods, devices, and systems described in this document. Furthermore, any aspect of the methods, devices, and systems described in this document can be combined with one another in a variety of ways. In particular, the features of the claims can be combined with one another in a variety of ways. Furthermore, features listed in parentheses are to be understood as optional features.

[0072] The invention will now be described in more detail using exemplary embodiments.

[0073] Figure 1a shows exemplary components of a vehicle;

[0074] Figure 1b shows an exemplary driving situation of a vehicle;

[0075] Figure 2a shows exemplary values ​​of drive and brake torques during operation of the vehicle;

[0076] Figure 2b shows an exemplary distribution of the effective total torque at a zero crossing of the vehicle's speed;

[0077] Figure 3 shows a flowchart of an exemplary procedure for operating a drive unit and a brake unit of a motor vehicle;

[0078] Figure 4 shows an exemplary release of the tension between the drive unit and the brake unit of a motor vehicle; and Figure 5 shows a flowchart of an exemplary method for controlling the tension between a drive unit and a brake unit of a motor vehicle.

[0079] As stated at the outset, this document deals with the reliable control of the tension between a drive unit and a brake unit of a motor vehicle, particularly in connection with an automatic, limiting intervention in the longitudinal guidance of the motor vehicle. In this context, Fig. 1a shows an exemplary vehicle 100 with one or more environmental sensors 102, each of which is configured

[0080] 24-1739 ABZ EXA 24.09.2024 are to acquire sensor data (also referred to as environmental data) relating to the environment of the vehicle 100. Examples of environmental sensors 102 are a camera, a radar sensor, a lidar sensor, an ultrasonic sensor, etc.

[0081] A (control) device 101 of the vehicle 100 can be configured to evaluate environmental data, e.g., to detect one or more objects (e.g., other vehicles) in the vicinity of the vehicle 100. The device 101 can further be configured to effect automated longitudinal and / or lateral guidance of the vehicle 100 based on the environmental data, in particular based on the one or more detected objects. For this purpose, one or more longitudinal and / or lateral guidance actuators 103, 106 (e.g., a drive unit 103, a brake unit 106, and / or a steering unit) of the vehicle 100 can be controlled.

[0082] The vehicle 100 typically includes an accelerator pedal 111, which allows the driver of the vehicle 100 to request a specific drive torque from the drive unit 103 of the vehicle 100. The drive unit 103 may, for example, include an electric machine. The drive torque requested by the driver (via the accelerator pedal 111) can be referred to as driver-side drive torque.

[0083] Furthermore, the vehicle 100 typically includes a brake pedal 112, which allows the driver of the vehicle 100 to request a specific braking torque from the vehicle 100's brake unit 106. The brake unit 106 may include one or more (hydraulic) friction brakes and / or wheel brakes. The braking torque requested by the driver (via the brake pedal 112) can be referred to as the driver-side braking torque.

[0084] The device 101 can be configured to limit the dynamics, in particular the acceleration and / or speed, of the vehicle 100 during the operation of an assistance system. For this purpose,

[0085] 24-1739 ABZ EXA 24.09.2024 The system limits the drive torque and / or the braking torque. These system-defined limits can be referred to as system-side drive torque limitation and system-side braking torque limitation, respectively.

[0086] The vehicle 100 typically has a transmission 104 that makes it possible to determine the direction of travel of the vehicle 100 (forward or reverse). In particular, it may enable the driver of the vehicle 100 to engage a gear, especially a forward gear or a reverse gear, in order to cause the drive unit 103 to generate a drive torque for the selected direction of travel.

[0087] It can happen that the vehicle 100 moves in the opposite direction to the selected gear or direction of travel. This can occur, for example, when driving uphill, as illustrated in Fig. 1b. Fig. 1b shows a driving situation in which the vehicle 100 is driving uphill on an inclined road 120. A driver-side drive torque 121, requested by the driver, acts in the selected direction of travel (i.e., uphill). Due to the incline, a gradient torque 123 acts in the opposite direction to the selected direction of travel. A driver-side braking torque 122, requested by the driver, always acts in the direction of bringing the vehicle 100 to a standstill. The direction of the driver-side braking torque 122 therefore depends on the actual direction of travel of the vehicle 100 and always acts in the opposite direction to the actual direction of travel of the vehicle 100.

[0088] Fig. 2a shows an exemplary operating situation of the vehicle 100 during an uphill drive, where the first column 200 applies to forward travel (according to the selected direction of travel) and the second column 250 to reverse travel (against the selected direction of travel). Based on the sensor data from one or more vehicle sensors 105, the inclination of the road surface 120 can be determined, for example. In particular, based on the sensor data, a

[0089] 24-1739 ABZ EXA 24.09.2024 The compensation torque 201, 251 is determined, which (by the drive unit 103) must be applied to compensate for the gradient torque 123 caused by the inclination of the roadway 120. In the example shown, the compensation torque 201, 251 is 1000 m.

[0090] The driver may be required to apply a driver-side drive torque 211, 261 (e.g., 6000 Nm). If a driver-side drive torque 211, 261 is required, a driver-side braking torque 212, 262 is typically not required. The sum of the driver-side drive torque and the driver-side braking torque 212, 262 results in a total driver-side torque 213, 263 (e.g., 6000 Nm in the example shown). From the total driver-side torque 213, 263 and the compensating torque 201, 251, a driver-side acceleration requirement 214, 264 results (e.g., 5 m / s²). 2 ).

[0091] System-level limitations can be set, e.g.

[0092] • a drive torque limit 221, 271 (e.g. 1000 Nm);

[0093] • a brake torque limit 222, 272 (e.g. 500 Nm, where the negative sign indicates that the respective torque acts against the current direction of travel); and / or

[0094] • a total torque limit 223, 273 (as the sum of the drive torque limit and the brake torque limit).

[0095] The torque limits each correspond to a specific acceleration limit 224, 274.

[0096] The one or more system-related limitations are preferably taken into account in the longitudinal guidance of the vehicle 100 in such a way that

[0097] • in the direction of the vehicle 100 coming to a standstill and / or in the event of movement against the selected direction of travel, no system-related limitation is taken into account (so that the dynamics of the vehicle 100 in the direction of standstill are not limited); and / or

[0098] 24-1739 ABZ EXA 24.09.2024 when the vehicle 100 moves in the selected direction of travel 200, the system-side limitation is taken into account (in order to limit the dynamics of the vehicle 100).

[0099] In the example shown in Fig. 2a, the total driver-side torque 213 for the selected direction of travel is greater than the total system-side limit 223, so that in this case the effective total torque 233 is determined by the total system-side limit 223.

[0100] On the other hand, the system-side overall limit 223 is not relevant for movement against the selected direction of travel, so that the effective total moment 283 is defined by the driver-side total moment 263.

[0101] This results in the vehicle 100 being decelerated to a standstill when rolling backwards uphill (i.e., when moving against the selected direction of travel) according to the total driver-side torque 263 (resulting in the effective acceleration 284). On the other hand, for the subsequent uphill travel (i.e., along the selected direction of travel), the effective total torque 233 is limited to the system-side total limit 223 (resulting in the effective acceleration 234).

[0102] The zero crossing of the vehicle speed 100, from a negative speed (due to movement against the selected direction of travel) to a positive speed (for movement along the selected direction of travel) can lead to an abrupt change in the torque to be provided by the drive unit 103 and / or the brake unit 106 (i.e., the effective drive torque 231, 281 or the effective brake torque 232, 282, respectively), which may be accompanied by a noticeable jerk of the vehicle 100, which may be perceived as uncomfortable by the driver of the vehicle 100.

[0103] 24-1739 ABZ EXA 24.09.2024 The device 101 can be configured to divide the effective total torque 233, 283 into an effective drive torque 231, 282 and an effective braking torque 232, 282 in such a way that when the vehicle speed 100 passes zero, there is no abrupt change in the torque to be provided by the drive unit 103 and / or the brake unit 106.

[0104] If the vehicle 100 moves against the selected direction of travel, the drive torque A 281 and the braking torque B 282 each act in the selected direction of travel. The effective total torque Si 283 is therefore Si = A + B.

[0105] When the vehicle 100 moves along the selected direction of travel, the drive torque A 231 acts in the selected direction of travel and the braking torque B 232 acts against the selected direction of travel (and is therefore negative). The effective total torque S2 233 is thus S2 = AB (where B is the magnitude of the braking torque 232).

[0106] From the two equations Si=A+B and S2=AB, the effective drive torque A and the effective braking torque B can be determined. Furthermore, the drive unit 103 can be operated depending on the effective drive torque A and the brake unit 106 depending on the effective braking torque B, in order to bring the vehicle 100 to a comfortable stop.

[0107] The brake unit 106 of a motor vehicle 100 can thus be actively controlled to ensure a particularly smooth zero crossing of the vehicle's speed during a transition from movement against the selected direction of travel to movement along the selected direction of travel. The control of the brake unit 106

[0108] 24-1739 ABZ EXA 24.09.2024 may be limited to operation in the near-standstill (transition) range, as exemplified in Fig. 2b.

[0109] Fig. 2b shows an exemplary time course of the vehicle speed 290 of the vehicle 100, starting from a negative speed (i.e., moving against the selected direction of travel), through a zero crossing, to a positive speed (i.e., moving in the selected direction of travel). The distribution of the effective total torque 233, 283 into an effective driving torque 231, 281 and an effective braking torque 232, 282, as described in this document, can be limited to a specific transition range 294 around the zero crossing. The transition range 294 can be defined by speed thresholds 291, 292.

[0110] Below a first (negative) speed threshold 291, the effective total torque 283 can be entirely allocated to the effective braking torque 282 or, alternatively, to the effective driving torque 281. From the first speed threshold 291 onwards, a gradual transition 293 to the distribution of the effective total torque 283 described in this document can then be effected.

[0111] Fig. 2b shows an exemplary time course 296 of the effective braking torque 282, and a time course 295 of the effective driving torque 281.

[0112] Upon reaching a second (positive) speed threshold 292, a smooth transition 293 to a state can be effected in which the effective total torque 233 is completely added to the effective driving torque 231.

[0113] 24-1739 ABZ EXA 24.09.2024 By limiting the distribution of the effective total moment 233, 283 to a near-standstill transition range 294, a particularly comfortable and efficient operation of the vehicle 100 can be achieved.

[0114] Fig. 3 shows a flowchart of a (possibly computer-implemented) method 300 for operating a drive unit 103 (in particular an electric drive motor) and a brake unit 106 (in particular a wheel and / or friction brake) of a motor vehicle 100 during a transition between a first movement of the motor vehicle 100 against the selected direction of travel and a second movement of the motor vehicle 100 in the selected direction of travel. The first movement is thus a movement against the selected direction of travel and has a negative speed. The second movement is a movement in the selected direction of travel and has a positive speed. The direction of travel can be determined by a selected gear of the transmission 104 of the vehicle 100. The method 300 can be executed by a (control) device 101 of the vehicle 100.

[0115] Method 300 comprises determining 301 a first effective total torque 283 for the first movement (i.e., for movement against the selected direction of travel) and a second effective total torque 233 for the second movement (i.e., for movement in the selected direction of travel). The second effective total torque 233 may depend on a system-side limitation of the drive and / or brake torque. The first effective total torque 283 may depend on a driver-requested drive and / or brake torque.

[0116] Method 300 further comprises determining 302 an effective drive torque 231, 281 and an effective braking torque 232, 282 on the basis of the first effective total torque 283 and the second effective total torque 233 such that the effective drive torque 231, 281 and the

[0117] 24-1739 ABZ EXA 24.09.2024 effective braking torque 232, 282 during the transition between the first and the second movement (i.e. at the zero crossing of the driving speed 290) do not change in magnitude (essentially).

[0118] Furthermore, the method 300 includes causing 303 to provide the effective drive torque 231, 281 to the drive unit 103 and the effective brake torque 232, 282 to the brake unit 106 for the transition between the first and the second movement.

[0119] The division of an effective total torque 233, 283 into an effective drive torque 231, 281 and an effective braking torque 232, 282 results in the drive unit 103 and the brake unit 106 (at least in the transition area 294) being preloaded towards or against each other and / or acting against each other. During the operation of the vehicle 100, an obstruction may occur that prevents such preload between the drive unit 103 and the brake unit 106 from being fully realized, which could lead to the desired effective total torque 233, 283 not being correctly applied.

[0120] Examples of obstacles that might prevent a tension from being fully or partially implemented between the drive unit 103 and the brake unit 106 are:

[0121] • a situation in which the drive unit 103 can no longer provide the effective drive torque 231, 281 at all or at least not completely, e.g. because the driving stage N (Neutral) has been selected, in which the drive unit 103 can and / or may no longer provide any drive torque; and / or

[0122] • a situation in which the brake unit 106 can no longer provide the effective braking torque 232, 282 at all or at least not completely, e.g. because the temperature of the brake unit 106 is too high

[0123] 24-1739 ABZ EXA 24.09.2024 has reached or exceeded a certain temperature threshold; and / or

[0124] • a situation in which the vehicle speed 100 is equal to or greater than a speed threshold (e.g. of approximately 10 km / h), especially since such a situation could lead to overheating of the brake unit 106.

[0125] The control device 101 of the vehicle 100 can be configured to detect one or more indications that an impediment exists which prevents a tension between the drive unit 103 and the brake unit 106 from being fully or at all implemented. In response, the tension can be reduced and, if necessary, completely eliminated. This can be achieved, for example, smoothly by using a fader or a crossfade factor.

[0126] Fig. 4 shows the driving situation from Fig. 2b, in which the effective total torque 233, 283 was distributed between the effective drive torque A 401 and the effective braking torque B 402. At a specific time 401, it can be determined that an obstacle exists, due to which the tension between the drive unit 103 and the brake unit 106 cannot be maintained, or at least not completely. Furthermore, the cause of the obstacle can be determined. In particular, it can be determined whether the cause lies with the drive unit 103 or with the brake unit 106.

[0127] In the example shown in Fig. 4, the reason why the tension between the drive unit 103 and the brake unit 106 cannot be maintained lies with the brake unit 106, e.g., because the temperature of the brake unit 106 reaches or exceeds a certain temperature threshold. In response, the tension can be reduced, at least partially or completely. For this purpose, the effective braking torque 282 can be reduced from time 401 onwards (see Fig. 4).

[0128] 24-1739 ABZ EXA 24.09.2024 (see diagrams 296, 406) and the effective drive torque. 281 can be increased (accordingly) (see diagrams 295, 405). The reduction, in particular the complete phase-out, of the tension preferably occurs smoothly (e.g., using a fader) over a specific crossfade period 403.

[0129] This describes a method by which one or more causes for the existence of an impediment to tension between the drive unit 103 and the brake unit 106 of the vehicle 100 are identified. Based on this, the tension can be partially reduced or completely eliminated.

[0130] To completely eliminate the tension, it can be ensured, for example, that when the vehicle 100 rolls forward along the selected direction of travel, the effective total torque 283 is completely assigned to the virtual accelerator pedal and / or the drive unit 103 if the effective total torque 282 is equal to or greater than zero. Conversely, when the vehicle 100 rolls forward along the selected direction of travel, the effective total torque 282 can be completely assigned to the virtual brake pedal and / or the brake unit 106 if the effective total torque 282 is equal to or less than zero.

[0131] If the vehicle rolls backwards in the opposite direction to the selected direction of travel, the assignment can be exactly reversed.

[0132] If a situation is identified in which the tension is to be reduced completely or partially, a blending factor can be used to smoothly transition from the respective initial tension situation to the target situation (e.g., to sole use of the drive unit 103 or sole use of the brake unit 106).

[0133] 24-1739 ABZ EXA 24.09.2024 Fig. 5 shows a flowchart of an exemplary (possibly computer-implemented) method 500 for operating a drive unit 103 and a brake unit 106 of a motor vehicle 100. The method 500 can be carried out by a control device 101 of the motor vehicle 100. The method 500 comprises, during a journey of the motor vehicle 100, causing 501 a tension between the drive unit 103 and the brake unit 106, whereby the drive unit 103 sets an effective drive torque 231, 281 to a non-zero level, and the brake unit 106 sets an effective brake torque 232, 282 to a non-zero level. The effective drive torque 231, 281 and the effective brake torque 232, 282 typically add up to an effective total torque 233, 283 for a movement of the motor vehicle 100.The tensioning between the drive unit 103 and the brake unit 106 can be caused in particular during a transition between a first movement against the selected direction of travel and a second movement in the selected direction of travel (as shown, for example, in connection with Figures 2a, 2b and / or 3).

[0134] Method 500 further includes determining 502 that there is an impediment to the tension between the drive unit 103 and the brake unit 106. An impediment could be, for example, degradation of the drive unit 103 and / or the brake unit 106.

[0135] Furthermore, in response to the determination 502, the method 500 comprises causing 503 the stress between the drive unit 103 and the brake unit 106 to be reduced or completely eliminated. The reduction of the stress can preferably be effected gradually over a specific blending period 401, e.g., using a blending factor.

[0136] The measures described in this document can ensure particularly reliable and comfortable operation of a motor vehicle at 100 km / h.

[0137] 24-1739 ABZ EXA 24.09.2024 Transition between a movement against the selected direction of travel and a movement in the selected direction of travel is effected.

[0138] The present invention is not limited to the embodiments shown. In particular, it should be noted that the description and the figures are intended only to illustrate the principle of the proposed methods, devices, and systems by way of example.

[0139] 24-1739 ABZ EXA 24.09.2024

Claims

Claims 1) Device (101) for operating a drive unit (103) and a brake unit (106) of a motor vehicle (100); wherein the device (101) is configured to operate the motor vehicle (100) during a journey, - to cause a tension between the drive unit (103) and the brake unit (106) in which the drive unit (103) produces an effective drive torque (231, 281) that is not equal to zero, and the brake unit (106) produces an effective brake torque (232, 282) that is not equal to zero; wherein the effective drive torque (231, 281) and the effective brake torque (232, 282) sum to an effective total torque (233, 283) for a movement of the motor vehicle (100); - to determine that there is an impediment to the tension between the drive unit (103) and the brake unit (106); and - in response to the determination, to cause the tension between the drive unit (103) and the brake unit (106) to be reduced or completely eliminated. 2) Device (101) according to claim 1, wherein the device (101) is configured, - to reduce the effective drive torque (231, 281) provided by the drive unit (103), in particular to zero, and to increase the effective braking torque (232, 282) provided by the brake unit (106), in particular in a complementary manner to the effective drive torque (231, 281); or - to reduce the effective braking torque (232, 282) provided by the brake unit (106), in particular to zero, and the effective drive torque (231, 281) provided by the drive unit (103), 24-1739 ABZ EXA 24.09.2024 in particular in a complementary manner to the effective braking torque (232, 282); and, in particular, such that the total effective torque (233, 293) remains unchanged in order to reduce the stress between the drive unit (103) and the brake unit (106). 3) Device (101) according to one of the preceding claims, wherein the device (101) is configured to reduce the tension between the drive unit (103) and the brake unit (106) smoothly over a blending period (403), in particular by means of a blending factor. 4) Device (101) according to one of the preceding claims, wherein the device (101) is configured, - to determine one or more indications of the existence of an impediment to the tension between the drive unit (103) and the brake unit (106); wherein the one or more indications relate to, - a selected gear position of the vehicle's transmission (100), in particular that gear position "N" is selected; - a temperature of the brake unit (106), in particular that the temperature of the brake unit (106) reaches or exceeds a temperature threshold; and / or - a vehicle speed (100), in particular that the vehicle speed (100) reaches or exceeds a speed threshold; and to determine, on the basis of one or more indications, that there is an impediment to the tension between the drive unit (103) and the brake unit (106). 24-1739 ABZ EXA 24.09.2024 5) Device (101) according to one of the preceding claims, wherein the tension between the drive unit (103) and the brake unit (106) is such that the effective drive torque (231, 281) provided by the drive unit (103) and the effective brake torque (232, 282) provided by the brake unit (106) counteract each other. 6) Device (101) according to one of the preceding claims, wherein the device (101) is configured to release the tension between the drive unit (103) and the brake unit (106) such that - the effective total torque (233, 283) for the motion of the motor vehicle (100) is entirely allocated to the effective driving torque (231, 281) when the effective total torque (233, 283) is equal to or greater than zero; and / or - if the effective total torque (233, 283) is equal to or less than zero, the effective total torque (233, 283) for the motion of the motor vehicle (100) - is fully allocated to the effective braking torque (232, 282) when the motor vehicle (100) is moving in the selected direction of travel; or - completely negated is assigned to the effective braking torque (232, 282) when the motor vehicle (100) moves against the selected direction of travel. 7) Device (101) according to one of the preceding claims, wherein the device (101) is configured to, upon a transition between a first movement of the motor vehicle (100) against a selected direction of travel and a second movement of the motor vehicle (100) in the selected direction of travel, - to determine a first effective total moment (283) for the first motion and a second effective total moment (233) for the second motion; 24-1739 ABZ EXA 24.09.2024 - to determine the effective driving torque (231, 281) and the effective braking torque (232, 282) on the basis of the first effective total torque (283) and the second effective total torque (233) such that the effective driving torque (231, 281) and the effective braking torque (232, 282) change in magnitude by no more than 10%, in particular by no more than 5%, during the transition between the first and the second movement; and - to cause the drive unit (103) to set the effective drive torque (231, 281) and the brake unit (106) to set the effective brake torque (232, 282) for the transition between the first and second movement. 8) Device (101) according to claim 7, wherein the device (101) is configured to determine the effective drive torque A (231, 281) and the effective braking torque B (232, 282) such that - A + B deviates by at most 10%, in particular by at most 5%, from the first effective total moment (283); and - A - B deviates by no more than 10%, in particular by no more than 5%, from the second effective total moment (233). 9) Method (500) for operating a drive unit (103) and a brake unit (106) of a motor vehicle (100); wherein the method (500) comprises, during a journey of the motor vehicle (100), - Causing (501) a tension between the drive unit (103) and the brake unit (106), whereby the drive unit (103) sets an effective drive torque (231, 281) to a non-zero level, and the brake unit (106) sets an effective brake torque (232, 282) to a non-zero level; wherein the effective drive torque (231, 281) and the effective brake torque (232, 282) sum to an effective total torque (233, 283) for a movement of the motor vehicle (100); 24-1739 ABZ EXA 24.09.2024 - Determine (502) that there is an impediment to the tension between the drive unit (103) and the brake unit (106); and - in response to determining (502), causing (503) that the tension between the drive unit (103) and the brake unit (106) is reduced or completely abolished. -1739 ABZ EXA 24.09.2024

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