WO2009049729A1 - Driver assistance system and method for supporting the driver of a vehicle during the transverse guidance of said vehicle - Google Patents

Abstract

The invention relates to a driver assistance system and to a method for assisting the driver of a vehicle (20) during the transverse guidance of said vehicle, In said method: lane information (Y, Yo, Ys) relating to a roadway driving lane (22) that is delimited by driving lane demarcations (220, 221) and/or a driving track (212) of a preceding guide vehicle (21) ahead of the vehicle (20) is detected by means of a lane identification device (11); the lane information forms the basis of the calculation in a controller (12) of a steering actuation set point (X) for a steering intervention in the vehicle (20) to keep to the lane, said steering intervention being carried out by means of a control unit (13). The degree of support afforded the driver by the steering intervention is varied depending on the current driving situation, the steering actuation set point (X) being modified and the steering intervention being carried out according to the modified steering actuation set point (X'). The steering actuation set point (X) is modified in an adaptation unit (15) that is provided as an interface between the controller (12) and the control unit (13).

Description

 Driver assistance system and method for assisting the driver of a vehicle in the transverse guidance of the vehicle

The invention relates to driver assistance system and a method for assisting the driver of a vehicle in the transverse guidance of the vehicle according to the preambles of the independent claims.

From DE 100 17 279 A1 a generic driver assistance system and a generic method are known in which the driver of the vehicle is relieved by the transverse and longitudinal guidance of the vehicle from the system in a typical for a stop-and-go operation low driving speed range is completely taken over. The transverse guidance of the vehicle can take place according to lane markings which are applied to the roadway traveled by the vehicle and which are detected by means of a video camera, or take place after a leading vehicle driving ahead of the vehicle. The well-known driver assistance system automatically shuts off when a predetermined limit speed is exceeded, thus offering the driver no assistance at high driving speeds.

From DE 199 19 644 C2, a driver assistance system for supporting the driver of a vehicle in the vehicle transverse guidance is known, in which a vehicle ahead of the vehicle is detected as a leading vehicle and wherein the distance to the leading vehicle and its direction angle to the longitudinal axis of the vehicle or the lateral distance between the vehicle and the leading vehicle are determined in order to calculate from these data a Lenkstellsollwert for a steering intervention on the vehicle, by which the vehicle is tracked as closely as possible to the leading vehicle in its path. This type of vehicle guidance is also referred to as object sequence control or drawbar control, because the vehicle follows the lead vehicle as if it were connected to it via a fictitious drawbar.

The known systems take over the lateral guidance of the vehicle completely and follow the vehicle to a system-determined setpoint track, without the driver having to help steer. The driver's need for support, which is dependent on the current driving situation, is not taken into account, so that the driver can feel the paternalism of the driver. This can lead to acceptance problems.

The invention is therefore based on the object of specifying a driver assistance system and a method according to the preambles of the independent claims, which allow in a simple manner an adaptation of the transverse guidance-assisting steering intervention to the current driving situation and thus to the situation-dependent varying support needs of the driver.

The object is solved by the features of the independent claims. Advantageous embodiments and modifications of the invention will become apparent from the dependent claims.

The driver assistance system according to the invention for assisting the driver of a vehicle in the transverse guidance of the vehicle, comprises a lane detection device for detecting lane information for the determination of a desired lane line, a control device for performing a steering intervention on the vehicle and a control device for determining a Lenkstellsollwertes for the steering intervention such that the Vehicle is guided by the steering engagement along the setpoint lane line, and an adjustment unit as an interface between the control device and the control device, which generates from the steering position setpoint a steering position setpoint modified by a driving situation. The controller performs the steering intervention according to the modified steering command value.

By the driving situation-dependent modification of the steering position setpoint, an adaptation of the steering intervention is achieved to the current driving situation. The adaptation is carried out with the aim of the degree of support offered to the driver, ie the degree of automation of the driver assistance system, depending on to adjust the current driving situation. A high degree of support means that the transverse guidance of the vehicle is essentially taken over by the system, so that the driver does not have to steer at all or at least to a small extent. On the other hand, a low level of support means that the driver essentially has to steer manually and that the system-side steering intervention only slightly assists the driver, but alone is insufficient to keep the vehicle on the target lane line.

In an advantageous embodiment of the invention, the regulator device is set up to calculate the steering setpoint value as a target steering torque to be applied to a steering system of the vehicle, and the adaptation unit is set up the modified steering setpoint value according to the formula

X ¹ = β ^• Ms

where β represents a situation-dependent adaptation parameter, which can take values between 0 and 1, and Ms represents the target steering torque.

In a further advantageous refinement of the invention, the control device is set up to calculate the steering setpoint value as a desired steering angle to be set on a steering system of the vehicle, and the adaptation unit is set up to modify the modified steering point setpoint value in accordance with

formula

X ¹ = β • δs + (1 - β) • δ ist

where β represents a situation-dependent adaptation parameter that can assume values between 0 and 1, δs represents the desired steering angle and δ is a detected current actual steering angle.

Advantageously, the adaptation unit is set up, the adaptation parameter as a function of the position of the vehicle relative to the target lane line and / or as a function of the vehicle speed and / or as a function of the driver to determine the steering system made steering intervention. The adaptation parameter is expediently determined on the basis of characteristic fields.

Preferably, the lane detection device comprises a position detection device for detecting lane-related lane information by detecting the relative position from the vehicle to the driven lane and by recognizing lane boundaries on a road used by the vehicle and / or an object detection device for detecting object-related lane information by detecting a lane of the vehicle leading vehicle ahead. The position detection device may comprise, for example, an image processing system which determines the position of the vehicle relative to the roadway and the lane markings for determining the lane boundaries with the aid of a video camera. In order to determine the lane boundaries, in addition to the lane markings, standing obstacles which constrict the passable lane area can also be used. In addition, the position detection device can also use satellite-based data from a Global Positioning System (GPS) and / or magnetic nails introduced into the roadway to determine the position of the vehicle and the lane boundaries. To determine the position of the vehicle and the lane boundaries and transponders can be used. The determination of the lane boundaries may also be based on beacons, which are used, for example, for site-specific lane constrictions.

In methods according to the invention for assisting the driver of a vehicle in the transverse guidance of the vehicle, lane information concerning a traffic lane limited by lane boundaries and / or a lane of a leading vehicle ahead of the vehicle is detected and the calculation of the steering point setpoint for a lane-keeping steering intervention on the vehicle used as the basis Degree of the support provided by the steering intervention depending on the driving situation is varied by modifying the Lenkstellsollwert and performing the steering intervention according to the modified steering position setpoint.

In this case, the steering setpoint value is preferably modified in such a way that the steering intervention is suppressed if the deviation of the vehicle from a setpoint lane line lies within a tolerance range predetermined in relation to the driving situation. Preferably the tolerance range depending on a determined driving speed of the vehicle and / or depending on the lane information given by the lane boundaries, such as the lane markings, limited lane and / or and width of the leading vehicle, in such a way that the tolerance range is greater at high values the driving speed or lane width or width of the leading vehicle than at low values of these variables.

Preferably, a driver intervention amount is detected, in particular a hand torque exerted by the driver on a steering system of the vehicle or an actual steering angle speed with which the driver actuates a steering wheel of the vehicle in order to modify the steering target nominal value as a function of the driver intervention variable in such a way that the steering intervention is suppressed, when the driver intervention amount exceeds a predetermined intervention threshold. The engagement threshold can be varied depending on the driving speed, for example, such that it decreases with increasing driving speed.

The particular advantage of the invention is that conventional control devices that communicate with each other via a data bus, for example via a CAN bus, can be used to calculate the steering command desired value or to perform the steering intervention, and that the degree of automation alone by modification of the steering target setpoint can be varied in an interface provided between the control units, without having to make a change in the control units for this purpose.

In particular, the invention makes it possible to adapt the degree of automation in such a way that a strong support with a high degree of automation is offered to the driver in driving situations with low driving speed, for example in stop-and-go Betheb, and weak support with low degree of automation in driving situations with high driving speed is offered. Such a type of assistance is particularly advantageous, since the driver's attention is usually lower in the low vehicle speed range than in the high vehicle speed range, and therefore the driver's need for assistance is higher in the low vehicle speed range than in the high vehicle speed range. The invention will be described in more detail by means of embodiments with reference to the figures. Showing:

1 is a representation of a typical traffic situation,

Fig. 2 is a simplified block diagram of the invention

Driver assistance system,

Fig. 3 is a more detailed block diagram of the invention

Driver assistance system,

4 shows a first characteristic field for determining an adaptation parameter for modifying the steering intervention,

5 shows a second characteristic field for determining an adaptation parameter for modifying the steering intervention,

FIG. 6 shows a third characteristic field for determining an adaptation parameter for modifying the steering intervention, FIG.

7 shows a fourth characteristic field for determining an adaptation parameter for modifying the steering intervention.

Corresponding parts are provided in all figures with the same reference numerals.

Figure 1 shows a typical traffic situation, as it can usually occur on a two-lane road. In the figure, the lanes of the road are designated by the reference numerals 22, 23. The lanes 22, 23 are limited by lane boundaries 220, 221, 230, in particular by lane markings, which are applied for example as color markings on the road. A vehicle 20 travels in the traffic lane 22 and follows a preceding vehicle 21. The vehicle 20 is a vehicle equipped with the driver assistance system according to the invention, which vehicle hereinafter referred to as a separate vehicle. The vehicle 21 is referred to below as a leader vehicle. A dotted line 222 marks it lane center of the lane 22. Standing obstacles, such as site beacons in construction areas, which narrow the passable road area, can be considered as lane boundaries 220, 221, which additionally influence the course of the dotted line 222 shown. In this case, the line 222 represents an obstacle-modified modified replacement lane center of the lane 22. A point 210 on the leader vehicle 21 marks a reference point of the leader vehicle 21, for example the lateral center of the leader vehicle 21. A dotted line 211 marks the course of movement of the reference point 210 A dotted area 212 marks the lane of the leading vehicle 21, ie the moving lane of the leading vehicle 21. A line 223 lies between the lines 222, 211, their exact position between the lines 222, 211 is determined via a prioritization factor. The double arrow Bo marks the width of the leading vehicle 21, the double arrow Bs marks the width of the lane 22, the double arrow dyo marks the lateral distance of the vehicle 20 to the leading vehicle 21, ie the distance of the vehicle 20 to the line 211. The double arrow dys marks the lateral Distance of the vehicle 20 from the track center 222, the double arrow dyf marks the lateral distance of the vehicle 20 to the line 223 and the double arrow dx marks the longitudinal distance of the vehicle 20 to the leading vehicle 21st

The lateral distances dys, dyo, dyf can either be defined as distances that refer to the instantaneous position of the vehicle 20, or be defined as distances that relate to a position point, the vehicle 20 after passing through a predetermined Vorschaustrecke is expected to take.

The object of the driver assistance system according to the invention is now to assist the driver of the own vehicle 20 in the transverse guidance of the vehicle, ie while holding a lane, wherein the lane to be maintained is determined by a setpoint lane line. In this case, depending on the method used in the driver assistance system, one of the lines 222, 211 or 223 is used as the setpoint lane line. Thus, in cases where the assistance in the sense of a lane following the lane boundaries 220, 221 is to take place, the line 222 is used as a target lane line. In cases where the assistance is to take place in the sense of a property following regulation after the leading vehicle 21, the line 211 is used as a setpoint trace line. In On the other hand, in cases where the support is to be made both for the lane boundaries 220, 221 and for the lead vehicle 21, the line 223 is used as the target lane line. In such a combined consideration of the lane boundaries 220, 221 and the leading vehicle 21 may be provided that the line 223 is shifted back and forth in accordance with a prioritization factor between the lines 222 and 211, wherein the prioritization factor is predetermined by the driver and / or driving situation-dependent in particular as a function of the driving speed of the vehicle 20, the recognizability of the lane boundaries 220, 221, the presence of the leading vehicle 21, or in dependence on a quality measure representing a quality measure for the detected lane boundaries 220, 221 or for the recognized leading vehicle 21.

According to FIG. 2, the driver assistance system 10 provided in the vehicle 20 comprises a lane recognition device 11, a control device 12, a control device 13, an adaptation unit 15 and a sensor arrangement 14. The lane recognition device 11 is provided for detecting lane information Y, which of the control device 12 and the adaptation unit 15 are supplied. The sensor device 14 is provided for detecting the driving speed v of the own vehicle 20 and for detecting an actual steering angle δ set at a steering system of the own vehicle 20. Depending on the configuration of the driver assistance system 10, the sensor device 14 may additionally be set up to detect an actual steering angular velocity δ and / or to detect a manual torque M h exerted by the driver on a steering wheel of the steering system of the vehicle 20. Furthermore, the sensor device 14 also provides the information about the width Be of the own vehicle. These quantities are output by the sensor device 14 as state information Z. The controller 12 calculates from the lane detection means provided by the lane detection device Y and provided by the sensor device as state information Z driving speed of the vehicle 20 a steering position setpoint X. The calculation is carried out such that the vehicle when performing a steering intervention according to the calculated steering position setpoint X automatically on a desired lane line is guided, wherein the desired lane line according to the embodiments of Figure 1 may be one of the lines 211, 222, 223. The adaptation unit 15 represents an interface between the regulator device 12 and the control device 13. It calculates a modified steering setpoint value X 'from the steering setpoint value X and sets this modified steering point setpoint value X' of FIG Control device 13 as an input available. The calculation of the modified steering position setpoint value X 'takes place as a function of the lane information Y provided by the lane detection device 11 and as a function of the state information Z provided by the sensor device 14.

In a first embodiment of the driver assistance system 10, the lane recognition device 11 comprises a video image processing-based position detection device for detecting the lane boundaries 220, 221, in particular the lane markings, and for determining the lane width Bs and for determining the lateral distance dys of the vehicle to the track center line 222. The lane width Bs and the lateral distance dys to the track centerline 222 represent lane-related lane information Ys output from the lane recognizer 11 as lane information Y. In this case, the support follows the track centerline 222.

In a second embodiment of the driver assistance system 10, the lane recognition device 11 comprises an object recognition device for detecting the preceding leading vehicle 21 and for determining the longitudinal distance dx, the lateral distance dyo and for determining the width Bo of the leading vehicle 21. These quantities represent object-related lane information Yo, which the lane detection means are outputted as lane information Y. In this case, the assistance follows the track line 211 of the preceding leading vehicle 21.

In a third embodiment of the driver assistance system 10, the lane detection device 11 includes both the above-mentioned position detection device and the above-mentioned object recognition device, and outputs the object-based lane information Yo and lane-related lane information Ys as lane information Y as lane information Y. In this case, the control takes place after the track line 223 lying between the track center line 222 and the track line 211.

Thus, in cases where the lane recognizer 11 outputs as the lane information Y only the lane-related lane information Ys, the lane centerline 222 is used as the target lane line in cases where the lane recognizer 11 as the lane information Y is only the object-based one Track Information Yo outputs the lane line 211 of the leading vehicle 21 as a target lane line, and in cases where the lane recognition device outputs as lane information Y both the lane-related lane information Ys and the object-based lane information Yo, the lane line 223 is used as the target lane line.

FIG. 3 shows the block diagram of the driver assistance system 10 for the case in which the lane recognition device 11 has both an object recognition device 111 and a position recognition device 112. In this case, the controller 12 computes a object following controller 121 and a lane following controller 122. The object following controller 121 calculates an object-based steering command value Xo from the object-based lane information Yo and the vehicle speed 20 provided as state information Z, and the lane-controller 122 computes accordingly from the lane-related lane information Ys and the vehicle speed 20 provided as state information Z of the vehicle 20 is a lane-related steering command target value Xs. In this case, the object-related steering setpoint value Xo is calculated in such a way that, when a steering intervention is carried out in accordance with the object-based steering setpoint value Xo, the vehicle is guided along the track line 211. The lane-related steering command target value Xs is calculated such that the vehicle is guided along the track center line 222 in accordance with the lane-related steering command target value Xs when performing a steering intervention. A prioritizer 123 fuses the object-based steering command setpoint Xo and the lane-related steering command setpoint Xs to the steering command setpoint X outputted from the controller means, wherein the merger is performed by weighted averaging according to the following formula:

X = α ^• Xo + (1-α) ^• Xs,

where α represents a prioritization factor, which can assume a value between 0 and 1, and which is detected as a function of the current driving situation, in particular depending on whether the lane and the lane boundaries 220, 221 and the leading vehicle 21 ahead or depending on the quality this detection is determined. In addition, the possibility can be provided for the driver to predetermine the prioritization factor .alpha. Via a driver input, for example via a menu entry, or to vary it within a certain range. The controller 12 may be configured to calculate the steering command target value X as a target steering torque Ms or alternatively calculate it as a target steering angle δs. The target steering torque Ms represents a steering torque that must be exerted on the steering system in addition to an applied by the driver on the steering system of the vehicle 20 hand torque to keep the vehicle on the target lane line. Accordingly, the target steering angle δs represents a steering angle that must be set on the steering system of the vehicle 20 in order to keep the vehicle on the target lane line.

In the event that the steering command value X is calculated as the target steering torque Ms, the modified steering position command value is calculated according to the following formula:

X '= β • Ms,

where β represents an adjustment parameter that can take values between 0 and 1, and where Ms is the target steering torque, i. H. the steering position setpoint X represents.

If the steering command value X is calculated as the target steering angle δs, the modified steering command value X 'is calculated according to the following formula:

X '= β • δs + (1-β) • δ ist,

where β represents an adaptation parameter, which may also assume values between 0 and 1, and where δs represents the desired steering angle and δ is the actual steering angle currently set on the steering system of the vehicle 20.

In both cases, the adaptation parameter β is determined as a function of the provided track information Y and the state information Z, ie. H. determined depending on the current driving situation. The determination is made on the basis of characteristic curves which are stored in the matching unit in a map memory 152.

FIGS. 4 to 7 show different examples of such characteristic fields. The characteristic field according to FIG. 4 is used if the assistance should take place after the track center line 222. In this case, β = β1a.

According to FIG. 4, β1a depends on the lateral distance dys and on the driving speed v. At minimum vehicle speed v close to standstill, the characteristic curve K10 is used to determine the adaptation factor .beta.1a. The characteristic K10 corresponds to the value β1a = 1, d. H. the steering setpoint value X is output unchanged to the control device 13 at the minimum driving speed v. Thus, at minimum driving speed v, one obtains a maximum degree of automation. As the driving speed v increases, a trench forms in the area around dys = 0, as indicated by the characteristic curves K11, K12, K13 and the arrows v shown in dotted lines. The ranges Δs1, Δs2, Δs3 denote tolerance ranges in which the adaptation factor β1a assumes the value 0. By means of the value β1a = 0, it is achieved that the steering setpoint value X is modified in such a way that the steering intervention to be undertaken by the control device 13 in accordance with the modified steering setpoint value X 'in the respective tolerance range is completely suppressed. Accordingly, the driver must steer manually at a lateral nominal distance dys in the respective tolerance range, and he only receives assistance from the driver assistance system 10 when the respective tolerance range is left. The corner points of the characteristic curves K11, K12, K13 are preferably additionally determined as a function of the lane width Bs and the vehicle width Be, namely in such a way that the tolerance ranges Δs1, Δs2, Δs3 increase with increasing lane width Bs. This ensures that the driver has to steer manually on wide roads in a larger track area and thus, compared to narrow streets, only later, close to the lane boundaries, receives system support.

If the assistance is to take place after the leading vehicle 21, ie after the track line 211, the adaptation parameter β is determined according to the characteristic field shown in FIG. 5, ie β = β1 b. The characteristic field according to FIG. 5 shows the relationship between the adaptation parameter β1 b and the lateral distance dyo of the vehicle 20 to the leading vehicle 21 and the driving speed v. Analogous to the characteristic field according to FIG. 4, a trench which widens with increasing driving speed v in the range around dyo = 0 is also formed in the characteristic field according to FIG. The tolerance ranges .DELTA.o1, .DELTA.o2, .DELTA.o3 become larger with increasing travel speed v, analogously to the tolerance ranges .DELTA.s1, .DELTA.s2, .DELTA.s3 that the driver also receives a higher level of support for the object-based assistance in the low vehicle speed range than in the higher vehicle speed range, in which the assisting steering intervention starts later than in the low vehicle speed range. The corner points of the curves K21, K22, K23 can also be varied depending on the width Bo of the leading vehicle 21, namely such that the tolerance ranges Δo1, Δo2 Δo3 increase with increasing width Bo.

With support based both on the lane-related lane information Ys and on the object-related lane information Yo, the determination of the adaptation parameter takes place on the basis of the characteristic fields according to FIG. 4 and according to FIG. H. the values of the adaptation parameters β1a and β1b are combined together to form a combined adaptation parameter β1c, for example by weighted averaging according to the formula

β1c = αβ1a + (1-α) β1b,

where α represents the aforementioned prioritization factor. For the calculation of the modified steering control signal X 'then β = β1c.

It may be advantageous, in addition to the characteristic curves in accordance with FIGS. 4 and 5, to additionally take into account a characteristic field according to FIG. 6 or a characteristic field according to FIG. 7 in the determination of the adaptation parameter .beta. The adaptation parameter β is then according to the equation

ß = ß1i ß2j

calculated with i = a, b or c and j = a or b.

The value β2a is determined according to FIG. 6 and the value β2b is determined according to FIG.

The value .beta.2a has, according to FIG. 6, a maximum value .beta.a = 1 at a small actual steering angular speed .delta.st, which decreases with increasing actual steering angular speed starting from a specific value of the actual steering angular speed .delta.st and from one Engagement threshold δg reaches a minimum value ß2a = O reached. The engagement threshold δg is above a steering angle speed which can be realized by the control device 13 and is advantageously shifted toward smaller values as the vehicle speed v increases, as indicated in the figure by the dashed curve K31 and the arrow v shown in dotted lines.

According to the characteristic K40 shown in FIG. 7, the value β2b has a maximum value of β2b = 1 at low values of the hand torque Mh exerted by the driver, then continuously decreases with increasing hand moment Mh above a certain value of the manual torque Mh and has a value of ß2 = 0 at a value of the manual torque Mh lying above an intervention threshold Mg. The engagement threshold Mg can thereby be shifted towards smaller values with increasing travel speed v, as indicated in the figure by the dashed curve K41 and the dotted arrow v shown.

The additional consideration of the curves shown in Figure 6 or 7 K30, K31 or K40, K41 makes it possible to suppress the steering operation made by the control device 13 when a noticeable driver-side steering activity is detected on the steering wheel of the vehicle 20. The driver can thus reduce or cancel the effect of the driver assistance system 10 by noticeably steering.

Claims

claims A driver assistance system (10) for assisting the driver of a vehicle (20) in the transverse guidance of the vehicle, with a lane recognition device (11) for detecting lane information (Y, Yo, Ys) for determining a desired lane line (211, 222, 223) with control means (13) for performing a steering intervention on the vehicle (20) and with a control device (12) for determining a steering setpoint value (X) for the steering intervention such that the vehicle (20) is guided by the steering engagement along the setpoint track line (211, 222, 223), characterized in that an adaptation unit (15) is provided as an interface between the control device (12) and the control device (13), which generates from the steering command setpoint (X) a steering position desired value (X ') modified according to the driving situation, and that the control means (13) modify the steering intervention according to Steering setpoint (X '). 2. Driver assistance system according to claim 1, characterized in that the control device (12) is set up, the steering position setpoint (X) as a on a Steering system of the vehicle (20) applied to calculate target steering torque (Ms), and the adjustment unit (15) is set, the modified steering position setpoint (X ') according to the formula X "= β ^• Ms where β represents a situation-dependent adaptation parameter and Ms represents the target steering torque. 3. driver assistance system according to claim 1, characterized in that the control device (12) is adapted to calculate the steering position setpoint (X) as a to be set on a steering system of the vehicle (20) target steering angle (δs), and the matching unit (15) is set, the modified steering position setpoint (X ') according to the formula X ¹ = β • δs + (1 - β) • δ ist where β represents a situation-dependent adaptation parameter, δs represents the desired steering angle and δ is a detected current actual steering angle. 4. driver assistance system according to claim 2 or 3, characterized in that the adjustment unit (15) is adapted, the adaptation parameter (ß) depending on the position (dys, dyo, dyf) of the vehicle (20) relative to the target track (211, 222, 223) and / or depending on the driving speed (v) of the vehicle (20) and / or in dependence on a steering intervention made by the driver on the steering system (Mh, δ ist). 5. Driver assistance system according to claim 4, characterized in that the adaptation unit (15) is set up, the adaptation parameter (ß) based on characteristic curves (K10, K11, K12, K13, K20, K21, K22, K23, K30, K31, K40, K41). 6. driver assistance system according to one of the preceding claims, characterized in that the lane recognition device (11) comprises a position recognition device (112) for detecting lane-related lane information (Ys) by recognizing lane boundaries (220, 221) on a lane traveled by the vehicle (20) and / or an object recognition device (111) for acquiring object-related lane information (Yo) by detecting a lane (211, 212) of a leading vehicle (21) ahead of the vehicle (20). 7. driver assistance system according to claim 6, characterized in that the position detection device (1 12) comprises a video camera for detecting image data and is adapted to detect the road-related lane information (Ys) based on the image data. 8. driver assistance system according to one of claims 6 or 7, characterized in that the position detection device (112) recognizes the lane boundaries (220, 221) on the basis of lane markings and / or obstacles on the lane, in particular on the basis of Baustellenbaken. 9. A method for assisting the driver of a vehicle (20) in the transverse guidance of the vehicle, wherein lane information (Y, Yo, Ys) concerning a limited by lane boundaries (220, 221) lane (22) and / or a lane (212) of a the vehicle (20) leading vehicle (21) are detected and the calculation of a steering point setpoint (X) for a tracking steering intervention on the vehicle (20) are based, characterized in that the degree of support provided by the steering intervention depending on the driving situation by modifying the Lenkstellsollwert (X) and performing the steering intervention according to the modified steering position setpoint (X ') is varied. 10. The method according to claim 9, characterized in that the steering position setpoint (X) is modified such that the steering intervention is suppressed when the deviation of the vehicle from a target track (211, 222) lies within a tolerance range (Δo1, Δo2, Δo3, Δs1, Δs2, Δs3) predetermined depending on the situation. 11. The method according to claim 10, characterized in that at least one of the parameters of driving speed (v) of the vehicle (20), lane width (Bs) of the lane boundaries (220, 221) limited lane (22) and width (Bo) of the leading vehicle (21) is detected and that the tolerance range (.DELTA.s1, .DELTA.s2, .DELTA.s3, .DELTA.o1, .DELTA.o2, .DELTA.o3) is predetermined depending on the driving situation so that it is increased if at least one of the parameters vehicle speed (v), lane width (Bs) and width (Bo) of the leading vehicle (21) increases. 12. The method according to any one of claims 9 to 11, characterized in that a driver intervention variable (Mh, δist) is detected, in particular a by the driver on a steering system of the vehicle (20) exerted manual torque (Mh) or an actual steering angular velocity (δist) with which the driver operates a steering wheel of the vehicle (20), and the steering command value (X) is modified such that the steering intervention is suppressed when the driver engagement amount (Mh, δist) exceeds a predetermined engagement threshold (Mg, δg).