Method for operating a lane guidance assistance of a vehicle which design driver intervention, lane

Abstract

The invention relates to a method for operating a lane guidance aid for a vehicle, comprising the following steps: activating automatic lateral guidance of the vehicle, a steering torque being applied by means of a steering system during the activated lateral guidance; deactivating the automatic lateral guidance if at least one predetermined deactivation event is detected, the applied steering torque being reduced for a predetermined deactivation duration at the time of deactivation; checking whether at least one deactivation event resulting in deactivation of the automatic lateral guidance is a driver intervention initiated by the driver of the vehicle; and if the deactivation event is a driver intervention, reducing the deactivation duration to a reduced deactivation duration.

Description

Technical Field

[0001] The invention relates to a method for operating a lane guidance assistant of a vehicle. The invention also relates to a lane guidance assistant for a vehicle. Finally, the invention relates to a vehicle having such a lane guidance assistant. Background Art

[0002] Lane guidance assistants for vehicles are well known from the prior art. Such lane guidance assistants, also referred to as steering and lane guidance assistants or active lane keeping assistants, are used in particular to keep the vehicle in a lane or lane. Such lane guidance assistants use data from one or more environmental sensors of the vehicle to identify the boundaries of lanes or lane markings. If these lane markings are detected with sufficient safety, the lane guidance assistant can be activated and a steering intervention can be carried out in order to keep the vehicle in the lane or lane. For example, the steering intervention can be carried out so that the vehicle is kept in the middle of the lane.

[0003] In the known prior art, there are basically two different forms of expression for the transition of an active lane guidance assistant from an active steering state to a passive non-steering state. A possible first transition is a sudden withdrawal of the steering support or a withdrawal of the steering torque. This sudden withdrawal can be noticed by a perceptible tremor on the steering wheel, which is caused by the separate withdrawal of the automatically set steering torque. A second known form of expression is a ramp-shaped withdrawal of the automatically set steering torque for support. Here, a fixed or current speed-dependent deactivation duration is defined, during which the currently set steering torque (which can be, for example, 2 Nm) is reduced to a steering support of 0 Nm. Summary of the invention

[0004] The object of the present invention is to specify a solution in which a lane guidance assistant of the type mentioned above can be improved in a situation-specific manner.

[0005] This object is achieved according to the invention by a method, a lane guidance assistant and a vehicle having the features according to the independent claims. Advantageous developments of the invention are described in the dependent claims.

[0006] The method according to the invention is used for operating a lane guidance assistant of a vehicle. The method comprises activating automatic lateral guidance of the vehicle, wherein a steering torque is applied during the activated lateral guidance by means of a steering system. The method further comprises: deactivating the automatic lateral guidance if at least one predetermined deactivation criterion is detected. In this case, during deactivation, the applied steering torque is reduced for a predetermined deactivation duration. The method further comprises checking whether at least one deactivation criterion leading to deactivation of the automatic lateral guidance is a driver intervention initiated by the vehicle driver. The method further comprises: if the deactivation event is a driver intervention, reducing the deactivation duration to a reduced deactivation duration.

[0007] Lane guidance assistants are used to assist the vehicle driver with steering tasks. In particular, lane guidance assistants are used to keep the vehicle in the lane or the current lane. Lane guidance assistants may also be referred to as steering and lane guidance assistants, active lane keeping assistants or steering assistants.

[0008] The lane guidance assistant may have at least one environmental sensor, with the aid of which environmental data can be provided. The environmental data describe the environment or surroundings of the vehicle. The environmental sensor may be, for example, a camera, with the aid of which image data can be provided as environmental data. Lane boundaries can be identified in the environmental data with the aid of the lane guidance assistant or a computing device of the lane guidance assistant. In particular, lane boundaries that delimit the lane in which the vehicle is currently located can be identified. It can also be provided that lane boundaries of other lanes or adjacent lanes are identified. Lane boundaries can in particular be road markings, such as solid or dashed lines or interrupted lines. However, lane boundaries can also be structural boundaries or the like. It can also be provided that the lane guidance assistant is activated if no lane markings are currently identified, but a vehicle ahead that is followed in so-called following driving is identified.

[0009] If these lane boundaries are reliably detected within a predetermined period of time with a predetermined probability or safety, the lane guidance assistant can be activated. This means that a steering torque is provided or a steering intervention is performed with the aid of the lane guidance assistant or the steering system of the lane guidance assistant in order to keep the vehicle in the lane or lane. However, the steering torque provided by the lane guidance assistant or the steering intervention provided can be overridden by the driver at any time by operating the steering wheel.

[0010] As already explained above, predefined deactivation events can occur which lead to deactivation of the automatic lateral guidance. Such a deactivation event can occur, for example, if lane markings are not recognized within a predetermined duration or are not recognized with sufficient safety. In this case, the automatic lateral guidance of the vehicle is deactivated or guidance of the vehicle is handed over to the driver.

[0011] In this case, the deactivation is not carried out suddenly, but rather over a predetermined deactivation duration. In particular, an indication or warning can first be output to the driver, namely that the automatic lateral guidance is switched off or that the driver should take over control again. During this deactivation duration, the steering torque provided by the steering system can be reduced. In particular, during the deactivation duration, the steering torque can be reduced completely or to a steering torque of 0 Nm. In this case, the steering torque can be reduced along a predetermined curve, such as a slope.

[0012] According to the invention, it is now provided that the deactivation event leading to the deactivation of the activated lane guidance assistant or the automatic lateral guidance is checked in more detail. In particular, it is checked whether the deactivation event is a driver intervention. A driver intervention can be, in particular, an action performed or initiated by the driver, which leads to the interruption of the automatic lateral guidance.

[0013] If the deactivation event is now identified as a driver intervention or caused by a driver intervention, the predetermined deactivation duration is reduced to a reduced deactivation duration. In other words, it is provided that in the case of a driver intervention as a deactivation event, a reduced deactivation duration is used to switch off or deactivate the automatic lateral guidance instead of the usual deactivation duration. The reduced deactivation duration is shorter than the predetermined or usual deactivation duration used in different deactivation events before the driver intervention. Thus, in the case of a driver intervention, a reduced or shorter deactivation duration is used than in a deactivation event not caused by a driver intervention.

[0014] The present invention is based on the recognition that the driver or the driver input is not taken into account when revoking the steering support or deactivating the automatic lateral guidance. Therefore, it often happens that the active lane guidance assistant is deactivated by the driver's steering intervention. Since according to the prior art, the driver input is not taken into account, the steering torque of the support provided is maintained during the predetermined deactivation period when the system is switched off. This results, for example, in that the driver still feels the force exerted by the system on the steering wheel, which in most cases points in the steering direction desired by the driver or at least does not exactly match the steering direction desired by the driver.

[0015] If systems according to the prior art reduce the steering torque only after or during a customary deactivation period, which can be several seconds, for example, the driver feels unsafe in this system and would like to interrupt or deactivate the lane keeping assistant by his driver input. This reduces the comfort and safety felt by the driver during the activation of the lane guidance assistant. This can lead in particular to the driver "fighting" the system for a short period of time, even though the driver actually wants to deactivate the system by his steering intervention.

[0016] With the method according to the invention, it is now possible to reduce the deactivation duration when automatic lateral guidance is deactivated due to driver intervention. This therefore leads to a faster deactivation of the automatic lateral guidance when the driver intervenes. By reducing the deactivation duration when the driver intervenes, the driver can quickly take over control of the vehicle again. This can also reduce conflicts, which occur, for example, when the driver takes action on a steering torque that is still being applied. Overall, it is thus possible to increase the comfort and safety in the operation of the lane keeping assistant.

[0017] Preferably, the steering torque provided can be reduced in a ramp-shaped manner or along a ramp during the deactivation period or the reduced deactivation period. Thus, the driver state and the driver input can be taken into account when determining the reduction time. During the deactivation period or the reduced deactivation period, a ramp-shaped reduction of the supported steering torque is provided for switching off the steering support. Thus, in order to determine the reduced deactivation period, i.e. the increase in the steering torque to be reduced, it can be assessed whether a driver intervention is the cause of the deactivation of the active lane guidance assistant.

[0018] In an embodiment, a steering wheel torque applied by the driver to the steering wheel of the vehicle and / or a steering wheel angle change caused by the driver on the steering wheel is detected as a driver intervention. The steering wheel torque can describe the torque applied by the driver to the steering wheel. For example, if the steering wheel torque exceeds a predetermined limit value, the automatic lateral guidance can be deactivated. If the change over time of the steering wheel torque exceeds a predetermined limit value, the automatic lateral guidance can also be deactivated. Alternatively or additionally, if the steering wheel angle change and / or the change over time of the steering wheel angle performed by the driver on the steering wheel of the vehicle exceeds the limit value, the automatic lateral guidance can be deactivated. Therefore, if an operating action or a steering intervention predetermined by the driver on the steering wheel is detected, this can be regarded as a deactivation event and therefore the automatic lateral guidance is deactivated. In these cases, it can be assumed with a high probability that the driver wishes to deactivate the automatic lateral guidance as quickly as possible.

[0019] Preferably, the activation of the direction indicator of the vehicle initiated by the vehicle driver is detected as a driver intervention. In other words, the manipulation of the turn signal lever or the activation of the turn signal can also be regarded as a driver-initiated deactivation event or driver intervention. This applies to the following situation, that is, the driver moves the turn signal lever to the engaged position or the warning flashing position. In the engaged position, the corresponding direction indicator is continuously activated without the driver having to hold the turn signal lever. In the warning flashing position, the corresponding direction indicator can be activated for a predetermined duration or a predetermined flashing cycle, wherein the turn signal lever returns to the static position when released. When manipulating the turn signal lever or activating the direction indicator, it can also be assumed that the driver wants to deactivate the activated lane guidance assistant.

[0020] In a further embodiment, an actuation of the brake pedal of the vehicle by the driver is detected as a driver intervention. For example, a lane guidance assistant or an automatic lateral guidance can be coupled to an automatic speed control, in particular an adaptive cruise control (ACC). Such a speed control can be deactivated by actuating the brake pedal. If the driver now presses the brake or the brake pedal, it can be assumed with a high probability that the driver wishes to deactivate the combined support of the longitudinal and lateral guidance.

[0021] It is also advantageous to determine the type and / or intensity of the driver's intervention and to determine the reduced deactivation duration according to the type and / or intensity of the driver's intervention. The type of driver intervention can in particular describe which driver intervention has been detected. For example, it can be checked whether the steering wheel torque applied by the driver on the steering wheel, the manipulation of the turn signal lever and / or the manipulation of the brake pedal are detected as driver intervention. If the driver applies a steering torque on the steering wheel, for example, then a shorter deactivation duration can be selected than in the case where the driver only manipulates the turn signal lever. If the driver applies a steering wheel torque on the steering wheel, for example, and therefore wishes to steer the vehicle manually, then it can be assumed that he wishes to terminate the function of the lane keeping assistant as soon as possible. It can also be checked whether the driver has performed multiple driver interventions. If multiple driver interventions are detected, then the deactivation duration can be further shortened.

[0022] The intensity of the driver's intervention can, for example, describe the magnitude of the steering wheel torque or the magnitude of the steering wheel angle. In addition, the change of the steering wheel torque and / or the steering wheel angle over time can be taken into account in order to determine the intensity. Thus, for example, it can be determined whether the driver only slightly overrides the steering torque provided by the steering system or whether the driver performs a significant steering intervention. In the case of a significant steering intervention or a high steering wheel torque or a large change in the steering wheel angle, a smaller reduced deactivation duration can be selected. Therefore, it can be deduced in general how quickly or urgently the driver wants to end the automatic lateral guidance. Based on this information, a reduced deactivation duration can be determined.

[0023] In a further embodiment, the current speed of the vehicle is determined and the deactivation duration is predetermined as a function of the current speed. A customary or standard deactivation duration can be predetermined as a function of the current speed of the vehicle. For example, the deactivation duration can be reduced as the speed increases. The reduced deactivation duration determined due to the driver intervention can be determined based on the speed-dependent deactivation duration. In other words, a cascade can be provided, wherein the deactivation duration is first determined as a function of the speed of the vehicle and then, if necessary, a reduction in the deactivation duration is provided when the driver intervenes.

[0024] The lane guidance assistant for a vehicle according to the invention is designed to activate automatic lateral guidance of the vehicle, wherein during the activated lateral guidance the steering system applies a steering torque. Furthermore, the lane guidance assistant is designed to deactivate the automatic lateral guidance if at least one predetermined deactivation criterion is detected, wherein upon deactivation the steering system reduces the applied steering torque for a predetermined deactivation duration. Furthermore, the lane guidance assistant is designed to check whether at least one deactivation event leading to deactivation of the automatic lateral guidance is a driver intervention initiated by the vehicle driver. Furthermore, the lane guidance assistant is designed to reduce the deactivation duration to a reduced deactivation duration if the deactivation event is a driver intervention.

[0025] The lane guidance assistant may be designed to guide the vehicle within a lane or a roadway. The lane guidance assistant may have an environmental sensor, in particular a camera, by means of which road markings may be detected. Furthermore, the lane guidance assistant may have a corresponding steering system by means of which automatic lateral guidance may be performed. Furthermore, the lane guidance assistant may be designed to detect driver interventions. For example, an actuation of the steering wheel, an actuation of the turn signal lever and / or an actuation of the brakes may be detected as a driver intervention.

[0026] A vehicle according to the invention comprises a lane guidance assistant according to the invention. The vehicle is designed in particular as a passenger car.

[0027] The preferred embodiments mentioned with reference to the method according to the invention and their advantages apply correspondingly to the lane guidance assistant according to the invention and the vehicle according to the invention.

[0028] Further features of the invention are obtained from the claims, the drawings and the description of the drawings. Without departing from the scope of the invention, the above-mentioned features and feature combinations mentioned in the description and the features and feature combinations mentioned later in the description of the drawings and / or shown only in the drawings can be used not only in the respectively specified combination but also in other combinations or alone. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The invention will now be explained in detail with the aid of preferred exemplary embodiments and with reference to the accompanying drawings.

[0030] Figure 1 A schematic diagram of a vehicle with a lane guidance assistant is shown;

[0031] Figure 2 Shown according to Figure 1 vehicles in an exemplary traffic situation in an exit area;

[0032] Figure 3 shows a curve over time of the steering torque during automatic lateral guidance and during deactivation of the automatic lateral guidance, wherein the deactivation is not due to driver intervention;

[0033] Figure 4 shows a curve over time of the steering torque during automatic lateral guidance and during deactivation of automatic lateral guidance, wherein the deactivation takes place due to driver intervention; and

[0034] Figure 5 A schematic flow chart of a method for operating a lane guidance assistant is shown. DETAILED DESCRIPTION

[0035] Figure 1 A vehicle 1, which is in the present case designed as a passenger car, is shown in a top view. The vehicle 1 comprises a lane guidance assistant 2, by means of which the vehicle 1 can stay in a lane 6 or a roadway. The lane guidance assistant 2 comprises a computing device 3, which can be formed, for example, by at least one electronic control unit of the vehicle 1.

[0036] Lane guidance assistant 2 also includes at least one environment sensor 4 . In the example shown, lane guidance assistant 2 includes environment sensor 4 , which is in the present case designed as a camera. Environment sensor 4 can provide environment data or image data describing environment 5 of vehicle 1 .

[0037] The computing device 3 is also designed to actuate a steering system 8, which is only schematically shown here, of the vehicle 1. By actuating the steering system 8, a steering torque or a steering intervention can be generated in order to keep the vehicle 1 in the lane 6 or roadway. By actuating the steering system 8, steerable wheels 9 of the vehicle 1 can be steered and the lateral guidance of the vehicle 1 can thus be influenced.

[0038] Furthermore, the lane guidance assistant 2 comprises a detection device 7, by means of which a driver intervention can be detected. A driver intervention can be a steering wheel torque applied by the driver of the vehicle 1 to the steering wheel. Furthermore, a driver intervention can be a change in the steering wheel angle performed by the driver on the steering wheel. Furthermore, a driver intervention can be an actuation of a turn signal lever of the vehicle. Finally, a driver intervention can be an actuation of the brake pedal by the driver.

[0039] Figure 2 Shown according to Figure 1 1 is a vehicle 1 in a schematic traffic situation. In this case, the vehicle 1 is located in a lane 6. The lane 6 is associated with a street 10. The lane 6 is limited by lane boundaries 11. Lane boundaries 11 are corresponding road markings applied to the road surface. With the aid of a computing device 3, lane boundaries 11 or road markings can be identified based on environmental data provided by environmental sensors 4. If these lane boundaries 11 are reliably identified, the function of the lane guidance assistant 2 can be activated. For this purpose, the lane guidance assistant performs a corresponding steering intervention in the steering system 8, so that the vehicle 1 is guided, for example, in the lane 6.

[0040] The current assumption is that Figure 2 In the traffic situation shown, the driver first notices later that he wants to leave the street 10 or the lane 6 via the exit 12. The driver activates the turn signal and attempts to quickly steer the vehicle 1 to the exit 12. These driver interventions lead to deactivation of the automatic lateral guidance.

[0041] Figure 3 The steering torque M applied by the steering system 8 is shown as a function of time t. In a first range 13, the time course of the steering torque M during the automatic transverse guidance of the vehicle 1 is shown. A deactivation event is detected at a deactivation time point 14, which leads to the deactivation of the active transverse guidance. In range 15, the time course of the steering torque M during the deactivation of the automatic transverse guidance is shown. It can be seen here that the steering torque M decreases in a ramp-shaped manner to a value of 0 Nm within the deactivation duration td. The deactivation duration td, during which the deactivation of the automatic transverse guidance is carried out, can be, for example, a few seconds.

[0042] exist Figure 2 In the example, Figure 3As shown, deactivation of the automatic lateral guidance within a conventional deactivation duration td can lead to a situation in which the driver becomes unsafe. In the situation shown, the driver wishes to deactivate the automatic lateral guidance or lane keeping assistant 2 as quickly as possible by his driver intervention in order to drive through the exit 12. However, a relatively long deactivation duration td can result in the driver applying a steering wheel torque that is directed toward the steering torque M of the steering system 8 or at least partially deviates from the steering torque M.

[0043] It is provided that a driver intervention is detected as a deactivation event and that, when a driver intervention is detected, the deactivation duration td is reduced to a reduced deactivation duration tr. Figure 4 As shown in the example, Figure 4 The steering torque M provided by the steering system 8 is shown as a function of time t. Here, too, the time curve of the steering torque M during active lateral guidance is shown by way of example in area 13. If a driver intervention is detected (in the form of an operation of the steering wheel, an operation of the turn signal lever and / or an operation of the brake), the deactivation period td is reduced to a reduced deactivation period tr. The reduced deactivation period tr can be, for example, a few milliseconds. This is currently Figure 4 This is schematically shown in the area 15 .

[0044] By adapting or reducing the inactivity duration td to a reduced inactivity duration tr, Figure 2 In a traffic situation such as , the following situation occurs: an actuation of the steering wheel and / or the turn signal by the driver is detected by means of lane guidance assistant 2. Therefore, a very short deactivation period tr is determined as an optimum value, so that after a few milliseconds the steering system does not apply a steering torque M to the steering wheel or the steering of vehicle 1. The driver can therefore perform a quick lane change from lane 6 to exit 12 without hindrance.

[0045] from Figure 2 Based on the situation, it is assumed that lane boundary 11 or road markings can no longer be reliably detected during the further journey. This also represents a deactivation event, which leads to the deactivation of lane guidance assistant 2. Since this deactivation is not a driver input initiated by the driver, a customary deactivation duration td of more than one second is determined as the optimal value.

[0046] At the deactivation point in time 14, the driver is preferably informed of the deactivation of the lane guidance assistant by a visual warning and, after a short reaction time, he begins to automatically regain full control of the vehicle and steer the vehicle 1 itself. In this case, a relatively long deactivation period td ensures that the vehicle 1 is still kept on the current route by the automatic steering torque M for a sufficiently long time and that the driver can take over the control without being too busy. Since the driver does not immediately make a steering movement pointing in a direction different from that in which the system was first steered, a long deactivation period td is not problematic in terms of comfort and conflicts with the driver.

[0047] Figure 5 A schematic flow chart of a method for operating a lane guidance assistant 2 of a vehicle 1 is shown. In step S1, the current speed of the vehicle 1 is determined. The deactivation duration td can be determined based on the current speed of the vehicle 1. For example, a shorter deactivation duration td can be selected at higher speeds. In step S2, when a deactivation event is detected, it is distinguished whether the deactivation event is a driver input. If the deactivation event is a driver input, the method continues in step S3. Here, a reduced deactivation duration tr is determined depending on the type and / or intensity of the driver's intervention. In particular, a ramp-shaped reduction of the steering torque M related to the time t can be determined.

[0048] If the query in step S2 identifies that the deactivation event is a deactivation event different from the driver input, the method continues in step S4. In this case, the speed-dependent deactivation duration td is not reduced. Therefore, in step S5, an optimized deactivation duration td or a reduced deactivation duration tr can be output for the current driving situation.

Claims

1. A method for operating a lane guidance assistant (2) of a vehicle (1), the method comprising the following steps: - activating an automatic transverse guidance of the vehicle (1), wherein during the activated transverse guidance a steering torque (M) is applied by means of a steering system (8), - deactivating said automatic lateral guidance if at least one predetermined deactivation event is detected, wherein, during deactivation, the applied steering torque (M) is reduced within a predetermined deactivation duration (td), It is characterized in that - checking whether the at least one deactivation event leading to deactivation of the automatic lateral guidance is a driver intervention initiated by a driver of the vehicle (1); and - if the deactivation event is the driver intervention, reducing the deactivation duration (td) to a reduced deactivation duration (tr).

2. The method according to claim 1, characterized in that A steering wheel torque applied by the driver to the steering wheel of the vehicle (1) and / or a steering wheel angle change achieved by the driver on the steering wheel is detected as a driver intervention.

3. The method according to claim 1 or 2, characterized in that: Activation of a direction indicator of the vehicle (1) by a driver of the vehicle (1) is detected as a driver intervention.

4. The method according to any one of the preceding claims, characterized in that An actuation of a brake pedal of the vehicle (1) by the driver is detected as a driver intervention.

5. The method according to any one of the preceding claims, characterized in that A type and / or intensity of the driver intervention is determined, and the reduced deactivation duration (tr) is determined as a function of the type and / or intensity of the driver intervention.

6. The method according to any one of the preceding claims, characterized in that A current speed of the vehicle (1) is determined and the deactivation duration (td) is predetermined as a function of the current speed.

7. A lane guidance assistant (2) for a vehicle (1), wherein: The lane guidance assistant (2) is designed to: - activating an automatic lateral guidance of the vehicle (1), wherein, during the activated lateral guidance, the steering system (8) applies a steering torque (M), - deactivating said automatic lateral guidance if at least one predetermined deactivation event is detected, wherein, when deactivated, the steering system reduces the applied steering torque (M) within a predetermined deactivation duration (td), It is characterized in that The lane guidance assistant (2) is further designed to: - checking whether the at least one deactivation event leading to deactivation of the automatic lateral guidance is a driver intervention initiated by a driver of the vehicle (1), and - if the deactivation event is the driver intervention, reducing the deactivation duration (td) to a reduced deactivation duration (tr).

8. A vehicle (1), in particular a passenger car, comprising a lane guidance assistant (2) according to claim 7.

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