Method for supporting a motor vehicle when performing a turn and driver assistance system

Abstract

The invention relates to providing support for a motor vehicle (10) when executing a turn with assistance. Thus, for executing a turn, two different assistance modes (21, 22) are provided in a driver assistance system (20), which set different potential turning speeds (vl, v2) for driving through a curve (61) respectively. In the invention, a selection routine is proposed in order to prioritize one of the two potential turning speeds (vl, v2) as a target speed for driving through the curve (61). According to the selection routine, for example, a set driving mode of operation (M) can be taken into account. In the selection, a fatigue level of the driver can additionally or alternatively be taken into account.

Description

Technical Field

[0001] This invention relates to a method for supporting a motor vehicle to turn using a driver assistance system. The invention also relates to a corresponding driver assistance system for supporting a motor vehicle to perform a turn. Background Technology

[0002] Driver assistance systems are commonly used in motor vehicles to support the driver in guiding the vehicle. For example, driver assistance systems can provide assisted or (partially) automated longitudinal guidance of the vehicle, i.e., acceleration and braking. Therefore, driver assistance systems can be used to maintain or adjust the actual speed of the vehicle. Thus, for example, a desired speed set by the driver can be set and / or a speed limit identified for permissible traffic speeds can be responded to. Additionally or alternatively, assisted or (partially) automated lateral guidance, i.e., steering of the vehicle, can be achieved with the aid of a driver assistance system. Therefore, driver assistance systems can assist when the vehicle's direction of travel changes. Thus, for example, lane keeping or driver-initiated lane changes can be performed.

[0003] Such driver assistance systems can be used to assist motor vehicles, for example, when turning. A corresponding method is known, for example, from DE 10 2016 215 064 A1. Here, the actual speed of the motor vehicle when driving through a curve is adjusted based on curve parameters and occupant preferences.

[0004] A method for displaying a recommended turning speed to a vehicle driver is also known from DE 10 2012 011 171 A1. The driver can use the recommended turning speed to guide the vehicle through a curve.

[0005] A method for generally assisting the driving of a motor vehicle is known from US2018 / 0194365 A1. In this method, at least one or more assistance functions are selected to support driving, based on the driver type and the identified driver state.

[0006] However, when actively guiding a vehicle laterally through a curve, there may be legal regulations limiting the maximum permissible or allowed turning speed for a vehicle to turn through the curve with assisted lateral guidance. There are generally no such legal regulations in active longitudinal guidance. More precisely, the turning speed here depends, for example, on the desired speed set by the driver or the actual traffic speed. If a vehicle is now traveling through a curve with both assisted longitudinal and lateral guidance, there may be different regulations regarding the set speed for traveling through the curve. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to resolve the differences between different speed specifications for assisted or (partially) automated turning.

[0008] This technical problem is addressed by the subject matter of the independent claims. Other possible embodiments of the invention are disclosed in the dependent claims, the specification, and the drawings.

[0009] This invention relates to a method for supporting turning of a motor vehicle with the aid of a driver assistance system that provides two different assistance modes. "Providing" means, for example, that both assistance modes can be perceived at the driver's side. Therefore, the driver of the motor vehicle can, for example, select and / or activate one of the modes as needed or preferred, to assist the driver while driving. Alternatively, it is conceivable to provide the two assistance modes together as a combined mode at the driver's side for selection. Then, at the driver's side, for example, only the combined mode can be perceived and can be selected and / or activated to assist while driving. Thus, the distinction between the modes can, for example, only be made at the technical level, i.e., in the background.

[0010] In the first assistance mode, lateral and longitudinal guidance of the vehicle are performed or provided. Therefore, when the first assistance mode is activated, at least partially, control over the (positive and negative) acceleration or maintenance of the driving speed and the steering of the vehicle is taken over. The first assistance mode can be, for example, so-called travel assistance (German: Reiseassistent).

[0011] Conversely, in the second assistance mode, only assisted longitudinal guidance of the vehicle is performed or provided. Therefore, when the second assistance mode is activated, only acceleration or maintenance of the vehicle's speed is achieved. The second assistance mode could be, for example, so-called Active Cruise Control (ACC).

[0012] In this article, "assistance" means the execution or implementation of corresponding assistance functions to support the driver in a specific driving task. In this article, "assistance" can also be understood as (partially) automated driving, which enables the motor vehicle to perform various driving tasks or driving functions at least temporarily without driver intervention.

[0013] The two assistance modes can overlap in their longitudinal guidance assistance functions. That is, with the first assistance mode activated, speed data from the second assistance mode can be used for longitudinal guidance, for example. Thus, the travel assistance can access speed data related to longitudinal guidance, such as the driving speed to be set, from the ACC. Regardless of which assistance mode is selected, the driver's desired speed or the actual permitted traffic speed can be maintained or set as the driving speed. Here, "set" means, for example, accelerating or braking to the desired speed or traffic speed.

[0014] The situation is different when a vehicle is assisted through a curve. Here, in the case of active lateral guidance, i.e., the active first assistance mode, the maximum permissible turning speed specifications described earlier must be followed for the set driving speed. Such specifications are known, for example, from UN ECE R79, which determines the maximum lateral acceleration a vehicle can withstand when driving through a curve. This maximum lateral acceleration can be pre-defined, for example, taking into account the driving speed and the curve geometry. The curve geometry can, for example, include data related to the curve radius and / or the width of the driving path. The faster a vehicle travels through a curve, the higher the lateral acceleration acting on it. However, since the lateral acceleration used for active steering is limited, this also leads to limitations on the permissible turning speed. Therefore, for assisted lateral guidance, the permissible turning speed is determined taking into account the pre-defined lateral acceleration.

[0015] Conversely, a pre-defined turning speed for active longitudinal guidance is generated, for example, based on a set desired speed or traffic speed. Therefore, in a specific driving situation, the permissible turning speed for assisted lateral guidance may deviate from the pre-defined turning speed for longitudinal guidance.

[0016] For assisted driving through curves in the activated first assist mode (in which lateral and longitudinal guidance should be implemented), two different turning speeds may be provided. The first potential turning speed is, for example, the legally permitted turning speed for assisted lateral guidance. The second potential turning speed is a pre-given turning speed, which is, for example, pre-given as the driver's desired speed for assisted longitudinal guidance.

[0017] In this invention, the difference between different speed specifications should be addressed, and here, one of the two potential turning speeds should take precedence over the other. To this end, in the method according to the invention, a first potential turning speed for driving through the upcoming curve in a first assist mode is compared with a second potential turning speed for driving through the curve in a second assist mode. If the comparison between the two potential turning speeds results in the first potential turning speed being less than the second potential turning speed, then, using a predetermined selection routine, one of the potential turning speeds is selected as the rated driving speed to be set when driving through the curve. The specific design of the selection routine will be discussed in more detail later.

[0018] Depending on the potential turning speed selected according to the selection routine, two possible scenarios for assisted driving through turns can now be realized. When the first potential turning speed is selected as the rated value, the turn is performed using a first assistance mode. "Use" specifically means that the first assistance mode is selected (i.e., reset) or retained (i.e., the first assistance mode is already activated and will continue to be used). Therefore, preferably, the vehicle is assisted in longitudinal and lateral guidance throughout its journey through or along the curve, wherein a slower travel assistance speed is used for longitudinal guidance.

[0019] Conversely, in the case where a second potential turning speed is selected as the rated value according to the selection routine, the first assist mode is used only for driving through the curve for such a short period of time that the actual lateral acceleration of the vehicle exceeds the pre-given lateral acceleration. Then, the system switches from the first assist mode to the second assist mode. In this text, "then" specifically means after a certain time. Therefore, this switch can be made, for example, with a time delay or immediately at the moment when the actual lateral acceleration exceeds the pre-given lateral acceleration. In the case of switching from the first assist mode to the second assist mode, the vehicle is therefore still only longitudinally guided assistedly or (partially) automatically. Lateral guidance must then be performed manually. That is, the driver must take over steering. Therefore, lateral guidance is discontinued at least in the curve section.

[0020] If a second potential turning speed is selected as the rated value, the vehicle's display devices, such as a monitor, instrument cluster, or head-up display, can be controlled. A driver message regarding whether the first assistance mode is deactivated is then displayed and provided to the driver. Deactivation can be indicated, for example, by hiding the symbol associated with the first assistance mode.

[0021] The advantage of using a selection routine is that it addresses the differences between different speed specifications used for turning. Based on the selection routine, one of the two potential turning speeds is given higher priority.

[0022] In the context of this invention, "curve" does not simply mean the entire section of the route that forms the curve. Alternatively, the term "curve" can also be understood as at least one section (curve segment) of a curve or a group of curves.

[0023] The invention also includes embodiments, which will be discussed in more detail below.

[0024] In one implementation, it relates to how two potential turning speeds can be determined or specified. For this purpose, it is specified that a first potential turning speed is determined based on a given first set of pre-curve data and the actual driving speed, taking into account a pre-given lateral acceleration. Correspondingly, a second potential turning speed is determined based on a pre-given second set of curve data, different from the first set of curve data, and the actual driving speed.

[0025] The first set of curve data can be, for example, one or more parameters related to the geometry of the curve. This includes, for example, the curve radius, the width of the driving path, and / or the curve length. To detect the first set of curve data, a camera device of the vehicle, such as a front-facing camera, can be used. The camera device detects or captures the ambient horizon ahead. The obtained image data can be evaluated using known image processing methods (e.g., pattern recognition), thereby deriving the first set of curve data. For this purpose, a neural network can be used, for example. To determine the first potential turning speed, the expected lateral acceleration of the vehicle in the curve ahead can be calculated in real time using, for example, a vehicle model simulated in the camera device. This calculation can be performed empirically using a neural network.

[0026] If the calculated expected lateral acceleration is greater than the pre-given lateral acceleration, or if the expected lateral acceleration is greater than the pre-given lateral acceleration by a predetermined tolerance, the actual driving speed is reduced until the lateral acceleration specification is met. The tolerance could be, for example, 10% of the pre-given lateral acceleration value. In other cases, such as specifying or setting the actual driving speed or a pre-given rated speed as a first potential turning speed, the pre-given lateral acceleration in the curve is maintained at this actual driving speed or pre-given rated speed. The rated speed could be, for example, the speed at which the vehicle should accelerate or brake to, as mentioned earlier, the driver's desired speed, or the aforementioned traffic speed. Therefore, a vehicle can also be in an acceleration phase when driving through a curve.

[0027] The second curve data set can be, for example, route data, i.e., one or more parameters related to the actual route. This includes, for example, speed limits pre-given by traffic signs and / or road users. Additionally or alternatively, group speed, i.e., the average speed of multiple other vehicles that have already traveled through the curve, can be provided as such a parameter. The second curve data set can be determined, for example, by evaluating digital map data provided by a navigation device associated with a driver assistance system. Additionally or alternatively, it is conceivable to provide the second curve data set by evaluating distance measurement data from the vehicle's radar system.

[0028] As an alternative to the foregoing implementation, two potential turning speeds can be determined, for example, based on a common set of cornering data, as previously exemplarily described. Here, in particular, the first turning speed is determined based on the common set of cornering data, taking into account a pre-given lateral acceleration, while the second turning speed is determined based on other preferences. That is, for example, a rated value for the second turning speed can be calculated without considering lateral guidance limitations.

[0029] The aforementioned selection routine will now be discussed in more detail in the following implementations.

[0030] Therefore, in one embodiment of the invention, the selection routine is executed only when the first turning speed and the second turning speed deviate from at least a predetermined limit by comparison. That is, the first turning speed should be less than or equal to the difference between the second turning speed and the limit in order to execute the selection routine. The limit can be, for example, a predetermined speed value of 10 km / h, 15 km / h, or 20 km / h. This avoids the driver being informed of conflicts with the driver assistance system even with small deviations.

[0031] In another implementation, a rated value is selected based on the vehicle's set driving profile mode, in conjunction with a selection routine. The driver assistance system can detect the driving profile mode, for example, based on the vehicle's system setting data. The driving profile mode can be set, for example, by the driver of the vehicle via input. For instance, if dynamic driving operation (e.g., Sport mode) is detected as the driving profile mode, the faster of the two turning speeds, i.e., the second potential turning speed, is selected in the selection routine. Conversely, if, for example, Comfort mode or ECO mode is selected as the driving profile mode, the slower turning speed, i.e., the first potential turning speed, can be set to the rated value. This provides the advantage of considering driver preference in the prioritization of turning speeds.

[0032] In another implementation, a rating is selected according to the selection routine based on the position of the gear lever, which represents the corresponding transmission mode of the vehicle. The vehicle may, for example, have a dual-clutch transmission. Such a dual-clutch transmission (DSG) typically provides two different transmission modes for operating the vehicle: manual and automatic. In manual mode, gear shifting is performed via driver input, such as by shifting levers. Conversely, in automatic mode, gear shifting is performed automatically, i.e., without driver intervention and therefore independently. If manual mode is now identified based on the gear lever position, a second potential turning speed can be selected, for example, to navigate a curve. When manual mode is set, it can be assumed that the driver of the vehicle wishes to guide the vehicle as much as possible and is prepared, in particular, to take over steering at any time. Conversely, in automatic mode, it can be assumed that the driver wishes to navigate curves as fully automatically or assistedly as possible. This also provides the advantage of considering driver preference when selecting a turning speed.

[0033] In another implementation, according to the selection routine, a rated value is selected based on the detected occupant condition of the corresponding occupant of the motor vehicle. The term "occupant condition" specifically means the physical or health condition of the corresponding occupant of the motor vehicle, particularly the driver. Specifically, the discomfort or fatigue of one of the occupants is identified by detecting the occupant condition, and a rated value is selected accordingly. Here, in cases where an occupant condition representing discomfort or fatigue has been determined, a first potential turning speed value can be selected. In other cases, a second potential turning speed value is selected as the rated value.

[0034] This prevents lateral guidance from being interrupted in curves, even if the driver's attention is already diverted due to their condition. By selecting a slower turning speed to assist lateral guidance, it also prevents occupant condition from deteriorating during travel.

[0035] Driver assistance systems can detect occupant status, for example, using occupant observation devices such as interior cameras, based on observational or image data. By evaluating the observational data using known image processing methods (e.g., pattern recognition), status values ​​associated with the corresponding occupant status can be detected. Therefore, the status values ​​provide information about whether the corresponding occupant is unwell, for example. "Unwell" here means dizziness and / or nausea. For example, the occupant's facial tone, pupil width, skin conductance, humidity levels indicating, for example, increased sweating, heart rate, other vital signs, and / or other values ​​describing physical or health status can be detected as status values. To determine whether an occupant is unwell, the detected status values ​​can be checked to see if they fall within pre-defined limit ranges. These limit ranges, for example, define the ranges associated with the occupant's discomfort. Within these limit ranges, occupant discomfort can be inferred. Conversely, outside these limit ranges, the occupant can be confirmed to be well.

[0036] In another implementation, a rated value is selected based on the detected state of the driver's attention, according to a selection routine. This involves determining the level of attention the driver is actually paying to observing or tracking the vehicle's movement and / or traffic conditions. Here, a first potential turning speed value can be selected if an attention state representing a lack of driver focus is determined. In other cases, a second potential turning speed value is selected as the rated value. This provides the advantage that when switching from a first assistance mode to a second assistance mode, it checks whether the driver is ready to quickly take over steering the vehicle. This prevents the vehicle from veering out of its lane and thus improves traffic safety.

[0037] To determine attention levels, one can check, for example, whether and / or how and / or with what grip strength the driver is holding the steering wheel. Additionally or alternatively, the driver's line of sight can be checked to determine attention levels. For this purpose, for example, an interior camera of the vehicle and / or a capacitive sensor device in the steering wheel can be used.

[0038] According to another implementation, a rated value in the selection routine is selected based on weather data detected in the vehicle's surrounding environment. The weather data describes the actual weather conditions in the vehicle's surrounding environment. The term "surrounding environment" specifically means the actual route and the route segments the vehicle may travel in the future. This specifically involves identifying the damage to driving operation caused by weather conditions by detecting the weather data and selecting a rated value accordingly. Here, if weather data representing the damage to driving operation is determined, a first potential turning speed value can be selected. In other cases, a second potential turning speed value is selected as the rated value.

[0039] Driver assistance systems can, for example, detect weather data from an external source using a communication module. Alternatively, the vehicle itself can be equipped with weather sensors to detect weather data and provide it to the driver assistance system. Weather data may include, for example, one or more weather-related values, such as temperature, humidity, sun position, and / or other weather-related parameters. To determine whether driving performance is impaired due to weather data, the relevant weather-related values ​​can be checked to see if they fall within predetermined limit ranges. These limit ranges define the intervals within which damage can be confirmed. For example, damage can be confirmed for temperatures below 4 degrees Celsius, sun positions less than 30 degrees from the driving path surface, fog formation, or humidity values ​​indicating a wet road surface.

[0040] This provides an advantage by adapting turning speeds to actual weather conditions. This allows for adjustments to vehicle operation when roads are slippery or wet, or when visibility is poor, thereby improving traffic safety.

[0041] In another implementation, in conjunction with the selection routine, a rating is selected based on group data of the detected motor vehicle group, wherein the group data includes the average turning speed of the motor vehicle group as it travels through the curve. "Motor vehicle group" here means multiple other motor vehicles that travel through the curve prior to this motor vehicle in time.

[0042] To select a rating, a group speed value, i.e., the average turning speed of the group of vehicles, can be determined and compared with first and second potential turning speed values. Then, for example, the turning speed whose value is closer to the group speed value can be selected as the rating for the turning speed. Additionally or alternatively, limits can be specified for each of the two potential turning speed values ​​to allow the potential turning speed values ​​to deviate as much as possible from the group speed value. If one of the two turning speed values ​​deviates beyond the limit, that turning speed is discarded as the rating, and the other potential turning speed is selected as the rating. For example, 50% of the group speed could be specified as the corresponding limit.

[0043] This provides an advantage, namely, the addition of a criterion for checking the reasonableness of the determined potential turning speed.

[0044] As an alternative to the above possibilities, the choice of which potential turning speed to use as the rated value can be based on the driver's preset. Therefore, the driver can, for example, specify that in conflict situations, either the first potential turning speed or the second potential turning speed should always be used as the rated value for driving through curves.

[0045] According to the selection routine, additional potential turning speeds can be considered when selecting the rating. These additional potential turning speeds could be, for example, the group speed mentioned earlier or the average of the first and second potential turning speeds. The additional potential turning speed can then be compared with the first potential turning speed. If the comparison shows that the additional potential turning speed is less than the first potential turning speed, then one of the potential turning speeds can be selected as the rating for driving through the curve using a predetermined selection routine. In this case, if the additional potential turning speed is selected as the rating, the first assist mode can be used to drive through the curve until the actual lateral acceleration of the vehicle exceeds a predetermined lateral acceleration. Then, for example, the second assist mode can be switched to.

[0046] The present invention also relates to a driver assistance system for supporting a motor vehicle and / or its driver when performing a turn as described above. The present invention may also relate to a motor vehicle having a corresponding driver assistance system.

[0047] Further features of the invention can be derived from the following description and from the accompanying drawings. The features and combinations of features mentioned above in the specification, as well as the features and combinations of features shown below in the description and / or individually in the drawings, can be used not only in the given combinations, but also in other combinations or individually, without departing from the scope of the invention. Attached Figure Description

[0048] In the attached diagram:

[0049] Figure 1 This diagram illustrates a motor vehicle approaching a curve to perform a turn with assistance.

[0050] Figure 2 A schematic diagram of a method flowchart showing the various method steps for selecting the turning speed of a motor vehicle to perform a turn is shown.

[0051] Figure 3 Showing according to Figure 2 A schematic diagram of one of the method steps, which involves selecting a turning speed based on the vehicle's driving mode.

[0052] Components that are identical or have the same function are given the same reference numerals in the accompanying drawings. Detailed Implementation

[0053] Figure 1 A schematic bird's-eye view of the vehicle 10 is shown. The vehicle 10 is in motion and is actually located on a straight section of the travel path 60 during travel, approaching a curve 61 ahead of the travel path 60. Figure 1 As shown, the motor vehicle 10 includes a driver assistance system 20. Using the driver assistance system 20, the driving operation of the motor vehicle 10 is supported and, in particular, assisted and / or (partially) automated, that is, at least partially automated without... Figure 1 The driver assistance system 20 operates without driver intervention, as not shown. It provides two different assistance modes 21 and 22, which the driver can select between to support driving operations. The first assistance mode 21 provides assisted lateral and longitudinal guidance for the vehicle 10. If the first assistance mode 21 is activated, the vehicle 10 can therefore steer with assistance (lateral guidance) and also accelerate with assistance, i.e., its speed can be changed (longitudinal guidance). The first assistance mode 21 is also referred to hereinafter as cruise assist. Conversely, in the second assistance mode 22, only assisted longitudinal guidance for the vehicle 10 is provided. The second assistance mode 22 is also referred to hereinafter as active cruise control or ACC (automatic distance adjustment).

[0054] To provide assisted lateral and / or longitudinal guidance respectively in the activated assistance modes 21 and 22, the driver assistance system 20 controls the driving-related components 30 of the vehicle 10 using corresponding control commands. For longitudinal guidance, for example, the speed regulation device 31 of the vehicle 10 is controlled as a component 30. For example, a rated or set value for the desired driving speed, or a parameter associated with the desired driving speed, such as an acceleration value, is provided as a control signal to the speed regulation device 31. For lateral guidance, for example, the steering device 32 of the vehicle 10 is controlled as a component 30. For example, the driver assistance system 20 can provide a desired rated or set value for the steering angle or turning angle as a control signal.

[0055] To operate a motor vehicle with both lateral and longitudinal assistance guidance, a first assistance mode 21 and a second assistance mode 22 can be used in a superimposed manner, for example. In superimposed use, for example, the first assistance mode 21 is integrated into the second assistance mode 22. That is, in the first assistance mode 21, data related to longitudinal guidance, such as the desired set driving speed, is determined, similar to the second assistance mode 22. How the set driving speed is determined in the second assistance mode 22 will be explained in more detail later.

[0056] However, due to the combined use of the two assistance modes 21 and 22 for lateral and longitudinal guidance, conflicts may arise for the driver assistance system 20 when performing a turn. This is because when performing a turn in the first assistance mode 21, the maximum pre-given lateral acceleration limit that the vehicle 10 may experience while navigating the curve 61 must be considered. Here, the specification for limiting the maximum lateral acceleration is based, for example, on legal regulations or guidelines. Such a limit on lateral acceleration is known, for example, from guideline UN ECE R79. Therefore, when navigating a curve, the lateral acceleration of the vehicle can, for example, be a maximum of 3 m / s². 2 This restriction also limits the speed at which vehicles can navigate corner 61 with assisted lateral guidance. This speed, also referred to below as the first potential turning speed v1, is used to describe the speed at which vehicles can navigate corner 61 with assisted lateral guidance.

[0057] To account for lateral acceleration limitations under activated lateral guidance, in the first assist mode 21, a first potential turning speed v1 is determined based on the first cornering data set 41 and the actual measured driving speed, taking into account a pre-given lateral acceleration. To detect the first cornering data set 41, Figure 1The vehicle 10 includes a camera device 40, which is designed, for example, as a front-facing camera. Using the camera device 10, the horizon of the environment ahead of the vehicle 10 is recorded, and the obtained image data is evaluated. Through evaluation, a first curve data set 41 is derived from the image data. The first curve data set 41 includes at least one or more parameters related to the geometry of the curve 61 ahead. Therefore, the curve data set may include, for example, the length of the curve 62 and the width of the travel path 63. The curvature or radius of curvature of the curve 61 is then determined based on the parameters. Then, based on the identified curve geometry, for example, in real time (i.e., during the approach of the vehicle 10 to the curve 61), the expected lateral acceleration of the vehicle 10 while maintaining an actually measured travel speed as it passes through the curve 61 is calculated. This calculation may be performed empirically, for example, using a neural network associated with the vehicle 10. The expected lateral acceleration is then compared with a previously given pre-defined lateral acceleration.

[0058] Based on the comparison, if the expected lateral acceleration in curve 61 is less than the predetermined lateral acceleration, then, for example, the actual speed of vehicle 10 is maintained to perform the turn. The first potential turning speed v1 is therefore defined as the actual speed. Conversely, if the expected lateral acceleration is greater than the predetermined lateral acceleration, the actual speed must be reduced until the predetermined limit of lateral acceleration is again met. In this case, the first potential turning speed v1 is therefore defined as the rated speed corresponding to the predetermined lateral acceleration. Therefore, by determining the first potential turning speed v1 in consideration of the predetermined lateral acceleration, the speed at which vehicle 10 is guided through curve 61 can be limited.

[0059] Regardless of the speed limit imposed by the first assist mode 21, due to the aforementioned superposition of the two assist modes 21 and 22, a second potential turning speed v2 is also determined for the execution of turns with assisted lateral and longitudinal guidance. The second potential turning speed v2 is here a driving speed determined in the second assist mode 22 for driving through curve 61, and through the superposition of assist modes 21 and 22, this driving speed can also be regarded as a possible driving speed for longitudinal guidance when the first assist mode 21 is activated.

[0060] Here, a second potential turning speed v2 is determined based on route data and the actual measured driving speed. This route data, also referred to as a second curve data set 51, can be used to perform the turn. For example, the second curve data set 51 or route data can be determined by evaluating digital map data provided by the navigation device 50 associated with the driver assistance system 20. Route data can be, for example, traffic data, such as speed limits identified by traffic sign recognition for specific sections of the route being traveled. Therefore, the second potential turning speed v2 can be defined by a driving speed pre-defined by the speed limits. Alternatively, the second potential turning speed v2 can, for example, correspond to a driving speed preset by the driver and thus to the actual driving speed of the vehicle 10.

[0061] Therefore, this results in different potential turning speeds v1 and v2 for assisted lateral and longitudinal guidance during cornering. The second potential turning speed v2 is generally greater than the first potential turning speed v1. When using the first potential turning speed v1 as the set travel speed, although the vehicle 10 will be guided more slowly through the curve 61, the cornering can be performed with fully assisted or (partially) automated lateral and longitudinal guidance. Conversely, when using the second potential turning speed v2 as the set travel speed, the vehicle 10 will be guided more dynamically through the curve 61, but manual steering must be taken over at least for the cornering section.

[0062] In order to perform a turn, two different potential turning speeds v1 and v2 are provided to the driver assistance system. The driver assistance system 20 must select one of these two different potential turning speeds v1 and v2 as the rated value for setting a new driving speed. Exemplarily according to... Figure 2 This section will explain in more detail how this choice can be made.

[0063] to this end, Figure 2 A schematic flowchart of a method is shown, comprising various method steps for selecting one of two potential turning speeds v1 and v2 to support the vehicle 10 during a turn. Here, in step S1, a first potential turning speed v1 is first compared with a second potential turning speed. In the comparison, as... Figure 2 As shown, for example, it checks whether the first potential turning speed v1 is less than the difference between the second potential turning speed and a predetermined limit amount vG. The limit amount vG can be, for example, 5 km / h or 10 km / h. If, according to the comparison in step S1, the deviation between the first potential turning speed v1 and the second potential turning speed v2 is less than the predetermined limit amount vG, then step S1 is repeated to perform the turn according to the method flowchart D. Conversely, if it is determined that the first potential turning speed v1 is less than the second potential turning speed v2 minus the limit amount vG, then the method continues with step S2.

[0064] In step S2, a selection routine is executed, which accurately selects one of two potential turning speeds, v1 or v2, for driving through the curve. Therefore, the rated value V for longitudinal guidance is determined. soll Please refer to later. Figure 3 Describe in more detail which criterion is used to select either the two potential turning speeds v1 or v2 based on the selection routine.

[0065] according to Figure 2 When the first potential turning speed v1 is selected as the rated speed v for driving through the curve... soll Then, the method continues with step S3. According to step S3, the first auxiliary module 21 is used here to guide the vehicle 10 laterally and longitudinally to travel through the curve in an assisted manner. Accordingly, the first auxiliary mode 21 can be retained for turning. Thus, the vehicle travels through the curve 61 more slowly, but entirely in a longitudinal and lateral guidance manner.

[0066] Conversely, if the second potential turning speed v2 is selected as the rated speed v according to the selection routine in step S2... soll The method then continues to step S4. In step S4, the first assist mode 21 is also first used for driving through the curve. However, here, during the turn, the actual lateral acceleration a of the vehicle 10 is continuously checked in step S5. ist Is it less than the previously given lateral acceleration a? vor Here, it is preferable to consider the expected lateral acceleration a. ist With the given lateral acceleration a vor The tolerance band for the deviation. That is, the lateral acceleration limit can be selected, which can be specified, for example, as 10% of a pre-given lateral acceleration.

[0067] If the expected lateral acceleration a is determined in step S5 ist If the lateral acceleration is less than the predetermined value, the method jumps back to step S4. Conversely, if the expected lateral acceleration 'a' in the curve is determined in step S5... ist Greater than the predetermined lateral acceleration a vor Then the method continues with step S6.

[0068] Then, in step S6, the system switches from the first assistance mode 21 to the second assistance mode 22. Therefore, when driving through curve 61 or at least a section of curve 61, the vehicle 10 is guided longitudinally only in an assisted manner. The driver must then manually take over lateral guidance, i.e., steering. In summary, when the second potential turning speed v2 is selected as the rated speed v according to step S2... sollAt that time, the first assist mode 21 was used for only this long to drive through the curve 61, until the actual lateral acceleration a ist Exceeding the predetermined lateral acceleration a vor Then, it switches from the first assistance mode 21 to the second assistance mode. That is, when driving through a curve, the lateral guidance of the vehicle 10 can be deactivated at least partially or temporarily in the curve section.

[0069] Figure 3 A schematic diagram of the method flowchart with each method sub-step of step S2 is shown again, wherein the sub-step is performed to select one of two potential turning speeds v1 and v2 as the rated speed v according to the previously mentioned selection routine. soll .according to Figure 3 Here, the selection is made according to the driving mode M set by the vehicle 10. For this purpose, in sub-step S21, the selection routine first checks which driving mode M of the vehicle 10 is actually set. The driver assistance system 20 can detect the driving mode M, for example, according to system settings stored in the vehicle's memory device (not shown) and, for example, pre-defined by the driver. Here, if the comfort mode ECO is set or stored as the driving mode M, the method continues to sub-step S22. In step S22, a first potential turning speed v1 is selected as the rated speed v for driving through the curve. soll Conversely, if the system settings detect dynamic mode DYN as driving profile mode M, the method continues with sub-step S23. In sub-step S23, a second potential turning speed v2 is selected as the rated speed for driving through curve 61.

[0070] As Figure 3 The alternative or addition to the design scheme of the selection routine shown in step S2 can select the rated value v based on the occupant status of the corresponding occupant of the detected motor vehicle 10. soll The fatigue level of an occupant, such as a driver, can be detected as an occupant state. The fatigue value indicates whether the occupant is fatigued, thus reflecting their fatigue level. This specifically involves identifying the fatigue of one of the occupants by detecting their state and selecting a rated value v accordingly. soll Here, given a determined occupant state representing occupant fatigue, a first potential turning speed value v1 can be selected. Otherwise, a second potential turning speed value v2 is selected as the rated value v. soll Fatigue values ​​can be, for example, the eyelid opening angle of the occupant's eyes or the occupant's blinking frequency. To detect fatigue values, the driver assistance system 20 can, for example, use an occupant camera to detect and evaluate the occupant's observation data or image data. For evaluation, known image processing methods, such as pattern recognition, can be used. Therefore, the rated speed v for driving through curve 61...soll The choice can be made based on, for example, whether the driver is prepared to take over lateral guidance at any time while driving through curve 61, or whether the driver's reaction time is expected to be limited due to fatigue.

[0071] Additionally or alternatively, it may be conceivable that, according to the selection routine in step S2, a selection is made from two potential turning speeds v1, v2 based on the detected group data of the vehicle group. The group data here includes the average turning speed (group speed) of the vehicle group traveling through curve 61. Therefore, for example, the selection routine may check whether the first potential turning speed v1 and the second potential turning speed v2 deviate from a predetermined limit amount of the group speed. For example, a value deviating 50% from the determined group speed may be predetermined as the limit amount.

[0072] The limit for the group speed range is determined by the limiting quantity. The first potential turning speed v1 and the second potential turning speed v2 should be located within this group speed range to be considered in the selection. Therefore, a rationality check can be performed on the selection of the rated speed. If one of the two potential turning speeds v1 and v2 is outside this range, then that turning speed v1 or v2 is unreliable and discarded. Then, the other turning speed of the two turning speeds v1 and v2 is selected as the rated speed v. soll If both potential turning speeds v1 and v2 are within the group speed range, then, for example, the potential turning speed closer to the pre-given group speed can be selected. However, if both potential turning speeds v1 and v2 are outside the pre-given group speed range, then, for example, the determined group speed can be specified as a new nominal value v. soll In this case, then it is possible to continue according to, for example, step S4 mentioned above. Figure 2 The method.

[0073] Overall, examples demonstrate how different assistance modes can be used to optimize a vehicle's turning speed to assist or (partially) automate turning.

[0074] List of reference numerals

[0075] 10 Motor vehicles

[0076] 20 Driver Assistance Systems

[0077] 21 First Assist Mode

[0078] 22 Second Assist Mode

[0079] 30 parts

[0080] 31 Speed ​​regulating device

[0081] 32 Steering mechanism

[0082] 40 Environmental monitoring devices

[0083] 41 First Curve Data Set

[0084] 50 navigation devices

[0085] 51 Second Curve Data Group

[0086] 60 Driving route

[0087] 61 bends

[0088] 62. Curve length

[0089] 63. Width of driving path

[0090] a ist Expected lateral acceleration

[0091] a vor Pre-defined lateral acceleration

[0092] D Method Flowchart

[0093] DYN Dynamic Mode

[0094] ECO Comfort Mode

[0095] M Driving Operation Mode

[0096] S1 Method Steps

[0097] S2 Method Steps

[0098] S3 Method Steps

[0099] S4 Method Steps

[0100] S5 Method Steps

[0101] S6 Method Steps

[0102] S21 Sub-step

[0103] S22 Sub-step

[0104] S23 Sub-step

[0105] v1 First Potential Turning Speed

[0106] v2 Second Potential Turning Speed

[0107] v G Limit quantity

[0108] v soll Rated speed

Claims

1. A method for supporting a motor vehicle (10) to turn using a driver assistance system (20), wherein, The driver assistance system (20) provides two assistance modes, and In the first auxiliary mode (21), assisted lateral and longitudinal guidance of the motor vehicle (10) is performed, and In the second auxiliary mode (22), only the auxiliary longitudinal guidance of the motor vehicle (10) is performed. Includes the following steps: - A first potential turning speed for driving through the curve (61) in the first assistance mode (21) is compared with a second potential turning speed for driving through the curve (61) in the second assistance mode (22). The first potential turning speed is determined for driving through the curve (61) taking into account a pre-given lateral acceleration of the vehicle (10). If the comparison shows that the first potential turning speed is less than the second potential turning speed, then, using a predetermined selection routine, one of the potential turning speeds is selected as the rated value for driving through the curve (61), and - For cases where the first potential turning speed is selected as the rated value, the first assistance mode (21) is used to drive through the curve (61), or - In the case where the second potential turning speed is selected as the rated value, the first assist mode (21) is used only to drive through the curve (61) until the actual lateral acceleration of the vehicle (10) exceeds the pre-given lateral acceleration, and then the vehicle is switched from the first assist mode (21) to the second assist mode (22). in, The first potential turning speed is determined based on a pre-given first curve data set (41) and the actual driving speed, taking into account the pre-given lateral acceleration, and the second potential turning speed is determined based on a pre-given second curve data set (51) different from the first curve data set (41) and the actual driving speed.

2. The method according to claim 1, wherein, According to the comparison, the selection routine is executed only when the first potential turning speed deviates from the second potential turning speed by at least a predetermined limit.

3. The method according to claim 1, wherein, According to the selection routine, the rated value is selected based on the driving profile mode set by the motor vehicle (10).

4. The method according to claim 1, wherein, According to the selection routine, the rated value is selected based on the position of the gear lever representing the corresponding transmission mode of the motor vehicle (10).

5. The method according to claim 1, wherein, According to the selection routine, the rated value is selected based on the occupant status of the corresponding occupant of the motor vehicle (10) as detected.

6. The method according to claim 1, wherein, According to the selection routine, the rated value is selected based on the detected attention state of the driver of the motor vehicle (10).

7. The method according to claim 1, wherein, According to the selection routine, the rated value is selected based on the weather data detected in the surrounding environment of the motor vehicle (10).

8. The method according to claim 1, wherein, According to the selection routine, the rated value is selected based on the group data of the detected motor vehicle group, wherein the group data includes the average turning speed of the motor vehicle group for driving through the curve (61).

9. A driver assistance system (20) for supporting a motor vehicle (10) when performing a turn according to any one of the preceding claims.

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