Method for controlling a motor vehicle, control device and motor vehicle

Abstract

The invention relates to a method for controlling a motor vehicle with a drive train which can be power-restricted for a limited period of time, in which method a check is carried out as a function of a vehicle state of the motor vehicle and at least one route characteristic of a route which extends from a starting point at which the motor vehicle is located to an entrance to a road with a predetermined minimum speed to determine whether a condition for lifting a time-limited power restriction of the drive train of the motor vehicle is met (Ü2) before the motor vehicle reaches the entrance, wherein after lifting the power restriction the motor vehicle can be driven by means of the drive train at least at the minimum speed.If it is determined that the condition is not met before the motor vehicle reaches the on-ramp, or if it cannot be determined whether the condition is met until the motor vehicle has reached the on-ramp, then an action of the motor vehicle is triggered (BM, EM).

Description

[0001] The invention relates to a method for controlling a motor vehicle, a control device and a motor vehicle.

[0002] EP 4 230 456 A1 discloses a control method for a hybrid vehicle.

[0003] Furthermore, DE 10 2019 101 254 A1 discloses a powertrain system for a vehicle that operates in one of several drive modes of the powertrain, including a pure motor drive mode, a pure electric drive mode, a regenerative braking mode, a coasting mode, and a motor / electric assist mode. The vehicle also includes a GPS sensor, a vehicle navigation system, a telematics system, a vehicle compartment monitoring system, and a controller. The controller includes an instruction set executable to determine a trajectory for the vehicle and to determine road conditions, traffic conditions, and surface conditions based on the trajectory for the vehicle and the road conditions, traffic conditions, and surface conditions.One of the drive modes of the powertrain is selected based on the trajectory for the vehicle and the road conditions, traffic conditions and surface conditions.

[0004] Furthermore, DE 10 2013 225 558 A1 discloses a method for determining a driving state of a hybrid vehicle for route segments of an upcoming route. The method comprises obtaining route data representing the upcoming route, wherein the upcoming route is divided into several route segments and the route data contains route information about the route segments. The method further comprises determining a suitability parameter for a predetermined driving state of the hybrid vehicle for each route segment based on the route information for the respective route segment. The predetermined driving state comprises at least one purely electric driving state, in which the electric motor drives the hybrid vehicle, and a second driving state, in which an internal combustion engine drives the hybrid vehicle.

[0005] DE 10 2021 100 326 A1 (D1) describes a vehicle with a traction battery that must provide the required power and a minimum speed to negotiate a gradient. To estimate the available wheel power upon arrival at the gradient, the state of charge and operating temperature of the traction battery upon arrival at the gradient, as well as the battery power, are predicted. Once it has been verified that the available power is greater than the required power, the vehicle enters the gradient with an autonomous driving command and negotiates it at a minimum speed.

[0006] DE 10 2017 127 029 A1 (D2) discloses a method in which, when a destination is specified in a navigation system, a battery's thermal state is analyzed with regard to possible routes. A control system 18 then selects a route to maximize battery performance. If the battery's operating temperature is not optimal (below 0 degrees Celsius or above 40 degrees Celsius), measures (heating or cooling measures) are initiated to ensure an optimal battery operating temperature.

[0007] DE 10 2021 213 957 A1 (D3) describes a method for controlling the temperature of a hybrid vehicle. A target temperature of an electric motor and / or an internal combustion engine is determined based on a distance to be covered. Subsequently, the actual temperature of the electric motor and / or the internal combustion engine at the beginning of the first distance is adjusted to the specified target temperature of the internal combustion engine (e.g., using a heat pump).

[0008] DE 10 2019 203 598 A1 (D4) describes a method that makes it possible to prevent unnecessary preheating measures for exhaust aftertreatment system components to reach operating temperatures. Furthermore, vehicle start-up is delayed or power is limited until the exhaust aftertreatment system components have reached a certain operating temperature.

[0009] In DE 10 2021 109 520 A1 (D5), the start of a motor vehicle is delayed until a predetermined state of the exhaust gas aftertreatment system, in particular a predetermined operating temperature of the exhaust gas aftertreatment system, is reached.

[0010] FR 3 103 771 A1 (D6) describes a method for optimizing the cold start phase of a hybrid vehicle. The aim is to increase the exhaust gas temperature to accelerate the heating of a catalytic converter.

[0011] The object of the present invention is to provide a solution which makes it possible to comply with traffic regulations despite a power limitation of a drive train of the motor vehicle which may be present when starting a motor vehicle.

[0012] This object is achieved according to the invention by the subject matter of the independent claims. Further possible embodiments of the invention are disclosed in the subclaims, the description, and the figures. Features, advantages, and possible embodiments presented in the description for one of the subject matter of the independent claims are to be regarded at least analogously as features, advantages, and possible embodiments of the respective subject matter of the other independent claims, as well as any possible combination of the subject matter of the independent claims, optionally in conjunction with one or more of the subclaims.

[0013] The invention relates to a method for controlling a motor vehicle, in particular a motor vehicle, in particular a passenger car or a commercial vehicle, in particular a light commercial vehicle. The motor vehicle comprises a drive train whose power can be limited for a limited period of time. The power limitation can, for example, be a temporary limitation of the engine power of an engine in the drive train. Alternatively, the power limitation can relate, for example, to the power provided by a traction battery, in particular if it is an electric drive train. For example, if the traction battery has not yet reached its operating temperature range, the power limitation can apply to the electric drive train. As soon as the operating temperature range of the traction battery is reached, the power limitation can be lifted.If the drive train comprises an internal combustion engine and an exhaust gas aftertreatment device, the power output of the drive train can be limited until the exhaust gas aftertreatment device has reached its operating temperature range. For example, it may happen that emission specifications for the exhaust gas aftertreatment can only be met once the operating temperature of the exhaust gas aftertreatment device has been reached. The method provides that, depending on a vehicle state of the motor vehicle and at least one route characteristic of a route extending from a starting point at which the motor vehicle is located to an entrance to a road with a predetermined minimum speed, a check is carried out to determine whether a condition for lifting an existing temporary power output restriction of the drive train of the motor vehicle is met before the motor vehicle reaches the entrance.

[0014] A road with a specified minimum speed could, for example, be a motorway, for which the road traffic regulations stipulate that it may only be used by vehicles capable of traveling at a speed of at least 60 km / h. If the motor vehicle is therefore unable to travel at a speed of at least 60 km / h due to the powertrain's power restriction, then it must be avoided that the motor vehicle enters the motorway. Conversely, it must be ensured that the moment the motor vehicle enters the motorway, the motor vehicle is capable of traveling at least at the minimum speed due to the removal of the power restriction.

[0015] Once the power restriction is lifted, the motor vehicle can be driven by the drivetrain at least at the minimum speed. In other words, a check is carried out to determine whether the route is sufficiently long or whether the power required by the drivetrain to move the motor vehicle along the route is sufficient to ensure that the condition for lifting the temporary power restriction is met. For example, a check is carried out to determine whether the power provided by the drivetrain to drive the motor vehicle along the route is sufficient to ensure that a drivetrain component causing the power restriction is heated to a temperature within its specified operating temperature range.If the method determines that the condition is not met before the motor vehicle reaches the on-ramp, or if it cannot be determined within the method whether the condition is met until the motor vehicle has reached the on-ramp, then an action by the motor vehicle is triggered. The motor vehicle's action is intended to ensure that the condition is met before or upon reaching the on-ramp and, as a result, that the power restriction is lifted at the latest at the on-ramp to the road with the specified minimum speed. If, for example, it is determined that the route is not long enough and thus the drivetrain component causing the power restriction has not yet reached its operating temperature range at the end of the route, then it is determined that the condition is not met before the motor vehicle reaches the on-ramp.The inability to determine whether the condition is met until the motor vehicle has reached the on-ramp can occur, for example, if information regarding the position of the motor vehicle and / or a position of the on-ramp, in particular in relation to the current position of the motor vehicle, is missing. If the position of the motor vehicle or the position of the on-ramp cannot be determined, then at least one route property of the route cannot be determined because the route itself cannot be determined. As a result, the second case arises in which, within the framework of the method, it cannot be determined, particularly due to a lack of information, whether the condition is met until the motor vehicle has reached the on-ramp. As a result, the action of the motor vehicle is triggered.The action is, in particular, a measure to shorten the distance to be covered with the power restriction until the power restriction is lifted. In particular, the measure is chosen such that the distance to be covered until the power restriction is lifted corresponds at most to the distance traveled by the motor vehicle from its position to the entrance to the road with a specified minimum speed.

[0016] According to the invention, it is provided that the action triggered is that heat is introduced into a component of the drive train. In particular, heat is introduced into the component of the drive train whose temperature is decisive for whether the power limitation of the drive train exists or not. In other words, the power limitation exists when the temperature of the component is below its operating temperature range, and the power limitation of the drive train is lifted when the temperature of the component is within its operating temperature range. By introducing heat into the component, the temperature of the component can be raised particularly quickly to such an extent that the temperature of the component lies within the operating temperature range.As a result, by introducing heat into the drivetrain component, the power limitation can be removed particularly quickly.

[0017] In this context, the invention provides for heat to be introduced into an exhaust system of the motor vehicle, as a component of the drivetrain, into an exhaust aftertreatment device. If the drivetrain includes the internal combustion engine, exhaust gas is produced when fuel is burned in the internal combustion engine. This exhaust gas must be aftertreated in the exhaust system in order to comply with specified emission values ​​for the exhaust gas. Compliance with the specified emission values ​​for the exhaust gas leaving the exhaust system can only be reliably ensured if the exhaust system and the exhaust aftertreatment device are at a temperature within the operating temperature range.The heat can be introduced into the exhaust system of the motor vehicle, into the exhaust gas aftertreatment device, by post-injecting fuel into the internal combustion engine and / or activating an exhaust gas burner and / or activating an electric catalyst heater and / or activating at least one heating disk and / or activating exhaust gas circulation. The measures mentioned enable a particularly targeted introduction of heat into the exhaust system. The post-injection of fuel into a combustion chamber of the internal combustion engine ensures that the fuel injected into the combustion chamber reaches the exhaust system via an exhaust valve in order to raise the exhaust gas temperature in a particulate filter and storage catalytic converter through oxidation. The exhaust gas burner can be used to heat the exhaust gas leaving the internal combustion engine before it reaches the exhaust gas aftertreatment device.This can shorten the time until the operating temperature range of the exhaust gas aftertreatment system is reached. For example, the exhaust gas burner can be a gas burner. The electric catalyst heater can, for example, comprise an electric heating element designed to directly heat a catalyst of the exhaust system. The heating disc can be a disc-shaped heating element, in particular an electric heating element. The heating disc can, in particular, be arranged particularly close to the component of the drivetrain into which heat is to be introduced. This enables particularly simple, precise, and therefore targeted introduction of heat into the specified component of the drivetrain.

[0018] The return of fully combusted exhaust gases with a lower oxygen content and a comparatively high CO2 content to the combustion process is known as exhaust gas recirculation. Exhaust gas recirculation refers to the return of exhaust gases to a combustion cycle. It serves to reduce emissions of nitrogen oxides produced during fuel combustion in the internal combustion engine. Exhaust gas recirculation reduces nitrogen oxides during combustion, allowing specified emission levels for the exhaust gas downstream of the exhaust aftertreatment system to be particularly well met.

[0019] In one possible embodiment of the invention, it is provided that the motor vehicle is additionally prevented from moving off until the condition is met. Alternatively or additionally, according to the invention, the motor vehicle is prevented from moving off until it is determined that, due to the heat already introduced into the drivetrain component, the condition will be met by the time the on-ramp is reached. If it cannot be determined whether the condition is met until the motor vehicle has reached the on-ramp, then it must be ensured that the motor vehicle only moves off when the condition for lifting the power restriction is met. Consequently, the motor vehicle is prevented from moving off in order to ensure that as soon as the motor vehicle moves off, the motor vehicle would be able to be driven at least at the minimum speed due to the power restriction being lifted.If it is determined that the condition is not met before the motor vehicle has reached the on-ramp, the motor vehicle can be prevented from moving off until it is determined that the determined distance traveled until reaching the on-ramp is sufficient to introduce into the drivetrain component the heat still required to meet the condition for lifting the power restriction. In other words, while the motor vehicle is stationary, so much heat is already introduced into the drivetrain component that the available distance traveled until the on-ramp is sufficient, that the energy introduced into the component while the motor vehicle is moving along the route is sufficient that the condition for lifting the power restriction is met when the motor vehicle reaches the on-ramp, for example as a result of the component having reached its operating temperature range.It can thus be ensured that once the motor vehicle has reached the entrance to the road at a specified minimum speed, the motor vehicle is able to be driven at least at the minimum speed due to the removal of the power restriction.

[0020] In a further possible embodiment of the invention, it is provided that a length of the route and / or a gradient of the route and / or a speed limit of the route are used as route characteristics for the check. The longer the route, the more heat can be introduced into the drive train component while the motor vehicle is traveling along the route. The longer the route, the more time there is to heat the drive train, in particular the drive train component, during normal operation of the motor vehicle. As a result of the fact that hot exhaust gases are generated by the internal combustion engine during normal drive of the motor vehicle and flow through the exhaust system, heat is introduced into the exhaust system, in particular into the drive train component.If the component causing the power restriction is the traction battery, it will also heat up during normal operation due to the power output of the traction battery for propelling the vehicle during normal operation. The longer the distance traveled, the higher the probability that the component's heating during normal operation will be sufficient to trigger the condition for removing the power restriction before reaching the ramp, without requiring any action from the vehicle.The steeper the gradient of the route, the more fuel must be burned in the internal combustion engine to propel the vehicle. Consequently, the more hot exhaust gas flows through the exhaust system, and the more power must be provided by the traction battery to a traction motor in the drivetrain. This results in larger currents flowing through the traction battery and, consequently, the traction battery heating up more quickly. In other words, the steeper the gradient of the route, the shorter the distance must be to fulfill the condition for lifting the temporary power restriction during normal operation. The higher the speed of the vehicle while traveling along the route, the greater the power required to propel the vehicle.The higher the speed of the motor vehicle, the more fuel is burned in the internal combustion engine, or the more power is provided by the electric traction battery for the drivetrain's electric traction motor. In other words, the higher the speed of the motor vehicle while traveling along the route, the shorter the distance the motor vehicle must travel to reach the condition for lifting the temporary power restriction during normal operation. If there is a speed limit on the route, it is assumed that the motor vehicle will travel along the route at a maximum of a specified maximum speed.This specified maximum speed thus determines the maximum power available from the drivetrain to propel the vehicle and consequently determines how quickly the drivetrain component causing the power restriction heats up during normal operation. The speed limit of the route can therefore influence how quickly the condition can be met when driving the vehicle along the route, for example, after how many kilometers have been traveled.

[0021] In a further possible embodiment of the invention, it is provided that the vehicle state is determined as a function of an actual temperature of at least one component of the drive train, in particular the actual temperature of the component causing the power restriction, and it is determined that the condition for lifting the power restriction exists when it is determined that the temperature of the component lies within the predefined operating temperature range for the component. In particular, it can thus be determined that the condition for lifting the power restriction exists when it is determined that the exhaust gas aftertreatment device of the motor vehicle has reached the predefined operating temperature range or the traction battery of the motor vehicle has reached its predefined operating temperature range.Whether it can be ensured that the condition for lifting the power restriction is met with a predetermined driving distance until reaching the on-ramp also depends on the actual temperature of at least one component of the drivetrain. This actual temperature of at least one component of the drivetrain can, for example, be significantly lower in winter than in summer. As a result, a given driving distance from a position of the motor vehicle to the on-ramp can, for example, be sufficient to meet the condition in summer but insufficient to meet the condition in winter. Thus, it may be necessary in winter for the action to be triggered because it is determined that the condition is not met before the motor vehicle reaches the on-ramp.

[0022] In a further possible embodiment of the invention, it is provided that as an action, route guidance from the starting point to the on-ramp is adapted. In particular, a route from the starting point to the on-ramp that is longer than the journey distance is selected in order to ensure that at least one component of the drive train is sufficiently warmed up by the time the on-ramp is reached, and thus the condition for lifting the power restriction is met. As an action, the motor vehicle can be controlled at least partially automatically, in particular fully automatically, along the longer route to the on-ramp. Alternatively, the driver can be prompted by an output device to ensure that the motor vehicle travels at least a predetermined number of minimum kilometers and / or at least a predetermined number of minimum minutes until it reaches the on-ramp.This longer adjusted route from the position of the motor vehicle to the on-ramp, compared to the original route, can be used as part of normal operation of the motor vehicle or with the addition of an action to heat the drivetrain component causing the power restriction in such a way that, at the latest when the on-ramp is reached, the temperature of the component is within the operating temperature range for the component and thus the condition for removing the power restriction is met.

[0023] In a further possible embodiment of the invention, it is provided that the on-ramp for determining the route to be checked is selected from at least two determined on-ramps depending on a user input and / or depending on a distance of the on-ramp from the starting point. In other words, the on-ramp can be determined depending on a user input which, for example, characterizes a distance of the on-ramp to be selected from the starting point of the motor vehicle and / or the selection of one of at least two determined on-ramps suggested to the driver for selection. It can therefore be determined on the basis of the user input which on-ramp the driver plans to drive the motor vehicle onto. Alternatively, in particular if no user input has been determined, an on-ramp closest to the starting point can be used for the check.This ensures that even if the motor vehicle is steered toward the nearest on-ramp, the condition for removing the power restriction is met upon reaching the on-ramp, either due to normal operation of the motor vehicle or due to at least one action of the motor vehicle. As a result, the motor vehicle can be driven at least at the minimum speed by the drivetrain following the removal of the power restriction. If the on-ramp is determined based on user input, the probability that the on-ramp actually desired by the user will be used for the check is particularly high.This can prevent unnecessary triggering of the action, for example, if the driver does not necessarily select the nearest on-ramp through their user input, but rather selects an exit up to which the driving distance from the starting point is sufficient so that the condition for lifting the power restriction is met upon reaching the on-ramp even without triggering the action. If no user input can be determined, selecting the nearest on-ramp can ensure that the condition for lifting the power restriction is always met as soon as the motor vehicle reaches an on-ramp, in particular the on-ramp closest to the motor vehicle's starting point.

[0024] The invention further relates to a control device which is designed to carry out a method as has already been described in connection with the method according to the invention for controlling a motor vehicle.

[0025] Furthermore, the invention relates to a motor vehicle with a control device as already described in connection with the control device according to the invention. The motor vehicle has a drive train whose power can be limited for a limited period of time. This power limitation can occur, in particular, depending on the temperature of a component of the drive train.

[0026] Further features of the invention can be derived from the following description of the figures and from the drawing.

[0027] The drawing shows in the only figure a process diagram for a method for controlling a motor vehicle.

[0028] In Fig. 1 shows a process diagram for a method for controlling a motor vehicle. This motor vehicle comprises a drive train whose power can be limited for a limited period of time. The drive train can comprise an internal combustion engine and / or an electric traction machine. If the drive train comprises the electric traction machine, the drive train additionally comprises a traction battery configured to provide electrical energy for the traction machine. The drive train can be power-limited, at least for a limited period of time, in particular depending on a temperature of at least one component of the drive train. In other words, the power limitation of the drive train depends on the temperature of the at least one component responsible for the power limitation.If the temperature of at least one component is outside the operating temperature range for this component, then the powertrain's power limitation is present. If the temperature of this component is within the specified operating temperature range, then the powertrain's power limitation is not present, or a condition for lifting the temporary power limitation is met, and consequently, the power limitation is lifted.

[0029] There may be certain roads with a specified minimum speed limit. This means that these roads may only be used by motor vehicles that can travel at least at the specified minimum speed. Examples of such roads include motorways in Germany, on which only motor vehicles capable of traveling at a speed of at least 60 km / h may travel. The motor vehicle is designed to be driven at least at the specified minimum speed, in particular at least 60 km / h, unless there is a power restriction.

[0030] The basic principle of Fig. The method shown in Figure 1 is based on the fact that, depending on a vehicle state of the motor vehicle and at least one route characteristic of a route, wherein the route extends from a starting point at which the motor vehicle is located to the entrance to the road with the predetermined minimum speed, it is checked whether the condition for lifting the temporary power restriction of the drive train of the motor vehicle is met before the motor vehicle reaches the entrance. If it is determined within the scope of the method that the condition is not met before the motor vehicle reaches the entrance, or if it cannot be determined whether the condition is met until the motor vehicle has reached the entrance, then an action of the motor vehicle is triggered.As part of the triggered action, it is provided that heat is introduced into the component of the drivetrain responsible for the power restriction. For example, heat can be introduced into an exhaust system of the motor vehicle as a component of the drivetrain, in particular by post-injecting fuel into a combustion chamber of the internal combustion engine and / or activating an exhaust gas burner and / or activating an electric catalyst heater and / or activating at least one heating disk and / or activating at least one exhaust gas circulation. It is possible that as an additional action, the motor vehicle is prevented from moving off until the condition is met, or the motor vehicle is prevented from moving off until it is determined that, due to the heat already introduced into the component of the drivetrain, the condition will be met by the time the on-ramp is reached.Whether the condition is met by the time the on-ramp is reached, and thus whether enough heat has been introduced into the component responsible for the power limitation by the time the on-ramp is reached, so that this component has a temperature within its operating temperature range, depends on the length of the route and the power required by the drivetrain to propel the vehicle along the route. Thus, the length of the route and / or a gradient of the route and / or a speed limit of the route can be used as route characteristics for the test.

[0031] The vehicle state can be determined depending on the actual temperature of at least one component of the powertrain, in particular depending on the actual temperature of the component responsible for the power restriction. If it is determined that the temperature of the component is within a predefined operating temperature range, then it is determined that the condition for removing the power restriction is met. If it is determined that the temperature of this component is not within this predefined operating temperature range and therefore outside the predefined operating temperature range, then it is determined that the condition for removing the power restriction is not met.

[0032] The following procedure scheme is described in Fig. 1 is explained in more detail. Reference is made here to normal measures NM, special measures BM and increased measures EM. Normal measures NM mean that the motor vehicle action is not triggered. Both for the provision of increased measures EM and for the provision of special measures BM, at least one action of the motor vehicle is triggered. An increased measure EM is a measure that results in the motor vehicle being able to reach the required minimum speed upon reaching the on-ramp. A special measure BM is a measure that results in the motor vehicle reaching the required minimum speed upon departure from the starting point, if necessary within a predetermined time interval after departure and thus shortly thereafter, and the power restriction is thus lifted.The enhanced EM measures and the special BM measures include engine-related measures that lead to faster achievement of the required minimum torque while simultaneously ensuring emissions compliance. In the powertrain that includes the internal combustion engine, these can include all measures that introduce heat into the exhaust system, such as post-injection, exhaust gas burners, electrically heated catalytic converters, heated discs, exhaust gas circulation, and departure delay.

[0033] A characteristic of the enhanced EM measure is that the vehicle can move from a standstill immediately and quite quickly after starting. It is very likely that, for various reasons, such as temporary limitation of engine power after a cold start for emissions-compliant warm-up, the vehicle may not be able to operate at full power immediately after starting, but may be able to drive off with limited power. Thus, the requirements for rapid warm-up with power limitation compete with the driver's desire to enter a road at a minimum speed and thus also at a minimum power level.If the distance from the starting point to the on-ramp to the road with the required minimum speed is known, it can be calculated whether the power available from the drivetrain at the on-ramp during the travel time along the route to this on-ramp is sufficient for emissions control reasons. In particular, the enhanced EM measure can recommend additional warm-up strategies to an engine control unit. These strategies benefit an earlier termination of the power limitation during the journey to the on-ramp, but would not be activated under normal circumstances, i.e., if entering the road at the minimum speed is not desired.

[0034] A characteristic of the special measure BM is that it is not known whether, how quickly and by which route the motor vehicle will reach the on-ramp from the starting point. The worst case scenario must therefore be assumed, for example that the vehicle has parked directly next to a motorway on-ramp and is to immediately use this motorway on-ramp to access the motorway. This means that high power is required as soon as the motor vehicle starts moving, which must be ensured by the special measure BM. This special measure BM can involve the motor vehicle heating up the exhaust system for a certain period while stationary after the vehicle or engine is started in order to be able to provide the required high power in accordance with emissions regulations when moving off. This is referred to as the "wait-to-drive" procedure. The extent of the respective measures increases from the normal measure NM to the increased measure EM to the special measure BM.The normal measure NM corresponds to a usual scope. This means that a torque / speed / power cap may still apply for the journey up to the on-ramp. The increased measure EM goes beyond the usual scope but remains below the special measure BM. This means that a cap corresponding to the normal measure NM may still apply, but this cap and thus the power limitation ends earlier than the normal measure NM because the increased measure EM is stronger, higher or more intensive than the normal measure NM as a result of the triggering of at least one action. The special measure BM establishes full readiness upon departure. This can mean that departure is only authorized once the vehicle's full performance capacity has been reached upon departure.

[0035] In the Fig.1, after a start S, environmental conditions and a vehicle state of the motor vehicle are recorded in a first method step V1. Subsequently, in a first checking step Ü1, a check is carried out to determine whether a positioning device is present in the motor vehicle. If it is determined in the first checking step Ü1 that the positioning device is present in the motor vehicle, the method follows the arrow marked J for yes to the second method step V2. In the second method step V2, the position of the motor vehicle is recorded. Subsequently, in a third method step V3, a route to the next access point with a minimum speed is determined using map data 12 received from a map catalog 10. In other words, the distance traveled from the starting point to the entrance to the road with the predetermined minimum speed is determined.In a subsequent fourth method step V4, a possible maximum speed of the motor vehicle upon reaching the nearest on-ramp to the motor vehicle is predicted, taking into account a traffic catalog 14 and / or the determined driving behavior 16. The maximum speed depends on whether the powertrain's power limitation exists or not. It can also be provided that the maximum speed achievable by the motor vehicle depends on the strength of the powertrain's power limitation. This means that the more the power of the powertrain is limited, the lower the maximum speed achievable by the motor vehicle.

[0036] In a subsequent second check step Ü2, a check is carried out to determine whether the minimum speed required for entering the road can be reached by the motor vehicle when reaching the slip road. If it is determined in the second check step Ü2 that the required minimum speed can be reached by the motor vehicle when reaching the slip road, the process follows the arrow marked J for Yes and normal measures NM are defined for the motor vehicle, which are carried out in a subsequent fifth procedural step V5. The process is then ended in a sixth procedural step V6. If it is determined in the second check step Ü2 that the required minimum speed cannot be reached by the motor vehicle when reaching the slip road, the process follows the arrow marked N for No to a third check step Ü3.During the third check step Ü3, a check is carried out to determine whether the motor vehicle should enter the road at the entrance at the minimum speed. If it is determined during the third check step Ü3 that entering the road at the entrance is not desired, the process follows the arrow marked N for No and the normal measures NM are defined. If it is determined during the third check step Ü3 that entering the road at the entrance is desired, the process follows the arrow marked J for Yes and increased measures EM are defined. After the measures have been defined, the measures in the fifth process step V5 are carried out and the process is then ended in the sixth process step V6. The entry of the motor vehicle onto a driveway can also be determined depending on a user input.In other words, the driver can be asked whether he or she wishes to access the road via at least one suggested entrance.

[0037] If it is determined during the first check step Ü1 that there is no positioning device in the motor vehicle or if the presence of the positioning device cannot be determined, the method follows the arrow marked N for No from the first check step Ü1 to the fourth check step Ü4. During the fourth check step Ü4 it is checked whether entering the road at the minimum speed via the slip road is planned. During the fourth check step Ü4, for example, the driver can be asked whether they even want to enter a motorway. If it is determined during the fourth check step Ü4, for example based on a received user input, that entering the road via the slip road is not desired, the method follows the arrow marked N for No and normal measures NM are defined.These normal measures NM are then carried out in the fifth process step V5 and the process is terminated in the sixth process step V6.

[0038] If it is determined during the fourth check step Ü4 that the driver wishes to enter the road via the on-ramp, the process follows the arrow marked Y for Yes to a fifth check step Ü5. In the fifth check step Ü5, a check is carried out to determine whether the route from the starting point at which the motor vehicle is located to the on-ramp can be characterized. In the fifth check step Ü5, the driver can be asked how far the motor vehicle is from the desired on-ramp. If the fifth check step Ü5 can determine how long the route is from the starting point of the motor vehicle to the on-ramp, the process follows the arrow marked Y for Yes.The arrow marked Y for Yes, starting from the fifth review step Ü5, results in the determination of the enhanced measures EM, which are subsequently implemented in the fifth procedural step V5. The procedure is then terminated in the sixth procedural step V6.

[0039] If the path to the access ramp cannot be characterized during the fifth verification step (Ü5), the procedure follows the arrow marked N for No and special measures (BM) are defined. These special measures (BM) are then implemented in the fifth procedural step (V5), and the procedure is subsequently terminated in the sixth procedural step (V6).

[0040] The characterization of the route in the fifth verification step Ü5 can include in particular a length of the route and / or a time of driving along the route and / or a topology of the route, in particular with regard to uphill driving or downhill driving.

[0041] For the enhanced EM measure, various options can be proposed to the driver. If it is determined that the driver's selected options are too low, and then excessive torque, engine speed, or power are requested when the vehicle is not ready, for example, due to a so-called "lead foot," the selection can be reduced for subsequent starts.

[0042] The described procedure is based on the realization that future emissions legislation will require strict compliance with emissions regulations. This can be achieved by preheating the exhaust system and by temporarily limiting the vehicle's power. While the power limitation is in effect, the driver of the vehicle may wish to enter a road with a minimum speed. However, the legally required power limitation must not result in the vehicle being driven below the required minimum speed. Without an appropriate solution, the vehicle would enter the road it is not permitted to use at that time because the vehicle's design-related maximum speed is below the required minimum speed.

[0043] The procedure involves querying environmental conditions and the vehicle's status – and thus also the available power in the context of a power limit for emissions reasons. Furthermore, position determination and position recording are performed. If these have been successfully performed, a map catalog can be used to determine the route to the next entry point with a required minimum speed and thus to the next road entrance with the specified minimum speed. With the help of catalogs of traffic conditions and driving behavior, a prediction can be made of the possible vehicle speed that can be reached when reaching the entrance, subject to all known vehicle restrictions, such as power limit for emissions reasons. If this speed is equal to or greater than the required minimum speed at the entrance, the normal NM measures are determined and implemented.If this is lower, a query is made as to whether access is desired at this entrance. If this is not the case, the normal NM measures are determined and implemented. However, if this access is desired, enhanced EM measures are implemented.

[0044] If position determination is not possible, a query is made as to whether an entry to the entrance is planned. If this is not the case, normal measures NM are defined and implemented. If, however, it is the case, a check is carried out as to whether it is possible to characterize the route to this entrance. If this is the case, the process continues from the above-mentioned point, from which the prediction of the maximum speed upon reaching the next entrance is made. Characterization cannot be carried out, special measures BM are defined and implemented. Furthermore, if an entry to the entrance is planned but this takes place via an alternative, particularly longer, route and the position cannot be determined, the enhanced measures EM can be defined and implemented. If, however, this alternative route cannot be characterized, the special measures BM are defined and implemented in this case.The special measures BM may additionally include, as an action, the issuing of an alert signal indicating that the departure of the motor vehicle is delayed because the exhaust system needs to be conditioned or that the traction battery needs to be conditioned and / or charged.

[0045] In principle, an assignment can be made that determines the minimum speed to be reached at the entrance based on the position of the vehicle, and thus a country-specific value. It is possible that if a case is identified that requires increased or special measures, the resulting action can be stored, which can be used to demonstrate compliance with legal requirements in case of doubt.

[0046] The motor vehicle can be a combustion-engine-powered vehicle and / or a battery-electric vehicle. In a battery-electric vehicle, the battery's charge level and / or temperature limit its performance.

[0047] Overall, the invention shows how an exhaust aftertreatment wait-to-drive process can be implemented on roads with a design-related minimum speed. List of reference symbols 10 Card Catalog 12 Map data 14 Traffic situation catalogue 16 Driving behavior BM special measure EM increased measure Y Yes N No NM normal measure S Start V1 - V6 respective process steps Ü1 - Ü5 respective verification steps

Claims

[1] Method for controlling a motor vehicle with a drive train which can be limited in power for a limited period of time, in which - depending on a vehicle condition of the motor vehicle and at least one route characteristic of a route extending from a starting point at which the motor vehicle is located to an entrance to a road with a predetermined minimum speed, it is checked whether a condition for lifting a temporary power restriction of the drive train of the motor vehicle is met (Ü2) before the motor vehicle reaches the entrance, wherein after lifting the power restriction, the motor vehicle can be driven by means of the drive train at least at the minimum speed, - if it is determined that the condition is not met before the motor vehicle reaches the entrance, or if it cannot be determined whether the condition is met until the motor vehicle has reached the entrance, an action of the motor vehicle is triggered (BM, EM), - where the action is triggered by introducing heat into a component of the drive train (BM, EM), ◯ whereby heat is introduced into an exhaust system of the motor vehicle as a component of the powertrain (BM, EM) by triggering at least one of the following measures: ▪ Post-injection of fuel ▪ Activating a flue gas burner ▪ Activating an electric catalyst heater ▪ Activate at least one heating disc ▪ Activating exhaust gas circulation, ◯ and wherein the motor vehicle is prevented from moving until it is determined that, due to the heat already introduced into the drivetrain component, the condition will be met by the time the on-ramp is reached. [2] Method according to claim 1, wherein, as an additional action, the motor vehicle is prevented from moving (BM) until the condition is met. [3] Method according to one of the preceding claims, wherein at least one of the following properties is used as a route property for the verification (Ü2): - Length of the route, - gradient of the route, - Speed ​​limit of the route. [4] Method according to one of the preceding claims, wherein the vehicle state is determined as a function of an actual temperature of at least one component of the drive train and it is determined that the condition for removing the power restriction exists when it is determined that the temperature of the component is within a predetermined operating temperature range. [5] Method according to one of the preceding claims, wherein as an action a route guidance from the starting point to the access point is adapted (EM). [6] Method according to one of the preceding claims, wherein the access for determining the route to be checked is selected from at least two determined access points as a function of a user input (Ü3, Ü4) and / or as a function of a distance of the access point to the starting point. [7] Control device which is arranged to carry out a method according to one of the preceding claims. [8] Motor vehicle with a control device according to claim 7.

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