DE202016001441U1 - Lane departure warning system - Google Patents

Abstract

A lane keeping assistance system for a vehicle having an environmental sensor system (1) for detecting the position of the vehicle (11) relative to a boundary of a lane traveled by the vehicle, a processing unit (4) for determining a steering correction suitable for keeping the vehicle (11) on the lane (δR) and a driver sensor system (7) for detecting the viewing direction (12, 23) of the driver (13), wherein the processing unit (4) is coupled to the driver sensor system (7) by the distance (d, d ') of an intersection point (16, 24), at which the direction of view (12, 23) of the driver (13) crosses the surface (14) of the traffic lane, from the vehicle (11) and the steering correction (δR) at a small distance of the intersection point (16, 24 ) greater than at long distance.

Description

The present invention relates to a lane keeping assistance system for a motor vehicle.

A driver assistance system in which a lane boundary is detected from data of a camera or a radar system and a warning is issued to the driver when the vehicle exceeds the lane boundary is, for. In DE 10 2011 087 459 A1 mentioned.

This known driver assistance system uses a camera aimed at the eyes of the driver to determine the driver's line of sight and to identify, from this viewing direction, an object in the surroundings of the vehicle which is to be subjected to special monitoring. An improvement of the lane keeping assistance function does not result from the monitoring of such a specified object.

An object of the present invention is to provide an improved lane keeping assistance system.

The object is achieved according to an embodiment of the invention, in a lane keeping assistance system for a vehicle having an environment sensor system for detecting the position of the vehicle relative to a boundary of a lane traveled by the vehicle, a processing unit for determining a for holding the vehicle on the lane suitable steering correction and a driver sensor system for detecting the line of sight of the driver, the processing unit is coupled to the driver sensor system to estimate the distance of an intersection where the driver's line of sight crosses the surface of the lane of the vehicle and the steering correction at a small distance of the intersection greater than at long distance.

If the intersection point is far from the vehicle, it can be assumed that the driver has already perceived the lane between the intersection and the vehicle and takes this into account when planning his steering maneuvers, and that sufficient time is available to carry out these steering maneuvers. In such a case, the driver assistance systems with steering corrections, whether they are merely suggested to the driver by appropriate signals or actively made by engaging in the steering, should be rather cautious. If, however, the intersection is close to the vehicle, it can be assumed that the driver, for. B. due to poor visibility or unforeseen road course, is busy with the navigation in the short distance and possibly fast, violent steering maneuvers may be necessary to keep the vehicle in the lane, so that in this case a more intensive assistance by the assistance system is helpful.

The assistance may be to issue a warning if the steering correction exceeds a first limit. The warning can be visual or audible, preferably a haptic warning, z. In the form of a torque applied to the steering wheel by the processing unit via a suitable actuator, which torque is perceived by the driver and which can cause the driver to steer in the direction indicated by the torque

The assistance, alternatively or in addition to the case described above, may be to intervene in the steering of the vehicle when the steering correction exceeds a second limit.

For detecting the viewing direction, the driver sensor system may comprise a camera directed toward the eyes of the driver.

The estimation of the distance of an intersection where the driver's line of sight crosses the surface of the traffic lane may be based solely on the viewing direction thus detected and the simplifying assumption that the roadway of the vehicle is parallel to vehicle longitudinal and transverse directions, ie evenly extending inclined plane. In addition, however, information about the height profile of the roadway can be used, the z. B. can be provided by a vehicle navigation system or based on ambient environment data such as images taken by a camera images of the road surface.

The driver sensor system may further be configured to detect the position of the driver's head in the longitudinal direction of the vehicle and to register whether it is involuntarily stretching forward in order to have a better view of the roadway in the vicinity of the vehicle. This information can be used by the processing unit to check the plausibility of a view-based distance calculation; in the simplest case, it can replace eye position monitoring by assuming, as the driver's line of sight, a line extending from the driver's eyes, grazing the leading edge of the hood, to the road surface.

The driver sensor system can also be set up to estimate the driver's viewing direction in the azimuthal direction. The processing unit can, if the viewing direction from the direction of Lane deviates, take a shorter distance than if the line of sight coincides with the direction of the lane. In this way, it can be taken into account whether the driver is watching the road ahead of the vehicle, or whether something else, such as a rearview mirror, gauges or dashboard controls, is taking his or her attention to warn earlier if necessary in the latter case or intervene in the steering.

The processing unit may be coupled to a directional headlamp to control a beam of the headlamp not only in a conventional manner depending on a steering angle set to steerable wheels of the vehicle, but also to deflect it by a yaw axis in the direction of steering correction. Thus, by directing the headlamp into a direction of travel suitable for keeping the vehicle on the lane, the processing unit also promotes the driver's inner readiness to steer in that direction.

Like the steering correction itself, the deflection of the beam at a small distance of the point of intersection should be greater than at a long distance.

The beam of the headlamp may also be pivotable about a pitch axis depending on the distance of the intersection. By making the inclination of the beam at a short distance greater than at a great distance, when the driver looks at the road near the vehicle, that part of the road can be illuminated more intensely, not only to the driver but also to the surrounding sensor to facilitate the detection of the lane course in the vicinity of the vehicle.

The object is achieved according to another embodiment of the invention by a method with the steps
Detecting the position of the vehicle relative to a boundary of a lane traveled by the vehicle, estimating the distance of an intersection where the driver's line of sight crosses the surface of the lane of the vehicle,
Determining a steering correction suitable for holding the vehicle on the lane, the steering correction being set greater at a short distance of the intersection than at a long distance.

The invention also relates to a computer program product with program code means which enable a computer to operate at least as a processing unit in a lane keeping assistance system as described above. If desired, the program code means may also enable the computer to perform environmental sensing tasks, such as identifying the boundary of a lane in camera-supplied lane images, or driver sensing, such as identifying the eyes in imagery delivered by a camera Driver and calculating the line of sight to take.

Another object of the invention is a computer readable medium on which program instructions are recorded which enable a computer to operate in the manner indicated above.

Last but not least subject of the invention is a computer system for installation in a vehicle, comprising means for detecting the position of the vehicle relative to a boundary of a lane traveled by the vehicle, means for determining a suitable for holding the vehicle on the lane steering correction and means for detecting the driver's line of sight, wherein the means are coupled to each other to estimate the distance of an intersection where the driver's line of sight crosses the surface of the lane from the vehicle and to set the steering correction at a greater distance from the intersection than at a long distance.

Further features and advantages of the invention will become apparent from the following description of embodiments with reference to the accompanying figures. Show it:

1 a vehicle on a roadway;

2 a block diagram of a lane keeping assistance system of the vehicle; and

3 a schematic section through the vehicle.

1 shows a schematic plan view of a vehicle 11 on a roadway 15 , here a two-lane road, is on the way. The lane 25 on which the vehicle is 11 may not be left unintentionally. For this purpose, the vehicle is equipped with a lane departure warning system whose components are in 2 are shown schematically.

An ambient sensor 1 of the lane departure warning system here comprises a camera 2 , which is mounted on the outside of the vehicle to take pictures of the lane in front of the vehicle 25 and in particular their mutual lane boundaries 26 . 27 to deliver, as well as an image evaluation unit 3 which is programmed to work in the camera 2 delivered images the lane boundaries 26 . 27 to identify and the distance of the vehicle 11 in the vehicle transverse direction y of the lane boundaries 26 . 27 and a curvature of the lane ahead 25 to calculate.

A processing unit 4 is provided to the basis of the image evaluation unit 3 supplied data to calculate a steering correction δ _R. The processing unit 4 and the image evaluation unit 3 can be implemented on a same microprocessor system.

The processing unit 4 may be a setpoint deviation .DELTA.y the position of the vehicle in the transverse direction of the lane traveled by him 26 set in different ways. When lane boundaries 26 . 27 on both sides of the vehicle 11 for the environmental sensor system 1 visible, Δy = 0 can be set when the distance to the lane boundaries 26 . 27 on both sides of the vehicle 11 is equal to; this distance can be used as a setpoint of the distance to the lane boundaries 26 . 27 be updated if on one side of the vehicle 11 the lane boundary 26 or 27 should no longer be recognizable.

zugrundegelegt werden. Sie berücksichtigt die Gierrate l_WBκ_C, die erforderlich ist, um einer Fahrbahn mit der von der Bildauswerteeinheit 3 gelieferten Fahrbahnkrümmung zu folgen, die anhand von Daten eines Tachometers 5 und eines Sensors 6 für die Lenkradstellung oder die Transversalbeschleunigung berechnete aktuelle Gierrate Δψ. Der Einfluss der Sollwertabweichung Δy ist umgekehrt proportional zu einer vom Fahrer überblickten Wegstrecke D_H der Fahrbahn, d. h. je weniger der Fahrer vorausblicken kann, um so dringlicher ist es, eine eventuelle Abweichung des Fahrzeugs 11 von seiner Sollposition auf der Fahrspur zu korrigieren, und um so größer ist folglich die Lenkkorrektur δ_R.When determining the steering correction δ _R , the formula

be based on. It takes into account the yaw rate l _WB κ _C , which is required to a lane with that of the image evaluation unit 3 delivered lane curvature, which is based on data from a tachometer 5 and a sensor 6 for the steering wheel position or the transverse acceleration calculated current yaw rate Δψ. The influence of the setpoint deviation Δy is inversely proportional to a distance D _{H of} the roadway covered by the driver, ie the less the driver can foresee, the more urgent it is to possibly deviate the vehicle 11 from its nominal position on the lane, and thus the steering correction δ _R is greater.

To estimate the length of the route D _H surveyed by the driver, is the processing unit 4 to a driver sensor 7 coupled. The driver sensors 7 includes a second camera 8th , which is mounted in the passenger compartment and aligned to the driver's head, and a second image evaluation unit 9 According to a first embodiment of the invention, programmed to be in from the camera 8th supplied images to identify the eyes of the driver and calculate their direction of view. Also the image evaluation unit 9 can on a same microprocessor system 10 with the processing unit 4 be implemented.

3 shows a schematic section through the vehicle 11 , wherein the cutting plane is perpendicular to the vehicle transverse or y-direction. The from the image evaluation unit 9 calculated line of sight 12 the driver 13 is inclined against the vehicle longitudinal or x-direction at an angle θ. If the surface of the roadway 14 is assumed to be the processing unit 4 knowing the height h of the eyes 15 the driver 13 above the roadway 14 able to measure the distance d between a reference point of the vehicle 11 and an intersection 16 at which the line of sight 12 the driver's lane 14 crosses, using simple trigonometric formulas to calculate and use this distance d as D _H in the above formula.

According to a further development, the processing unit 4 in addition to a vehicle navigation system 17 be coupled (see 1 ), which provides information about the topography of the road ahead 14 supplies and so the processing unit 4 offers the possibility of calculating the point of intersection 16 taking into account this topography to improve. So z. B. be taken into account that the driver when approaching the vehicle 11 at a depression must lift the view to the roadway 14 beyond the valley, and the true distance d of the intersection 16 in such a case is smaller than when driving on a level road.

The vehicle navigation system 17 According to a modification, instead of the image evaluation unit 3 can be used to calculate the curvature of the road ahead of the vehicle or the image evaluation unit 3 assist in the calculation of the road curvature.

The image evaluation unit 9 can be programmed to be next to the line of sight 12 in the sectional plane of the 3 , ie the zenith angle θ of the viewing direction 12 also to calculate their azimuthal angle ψ, ie based on 1 a deviation of the viewing direction 12 from the direction of the lane 25 capture. If a significant deviation suggests that the driver is not on the road 15 looks, but z. B. in a rearview mirror or on a center console of the vehicle 11 , then this can be taken into account in the determination of the steering correction δ _R by a low value for D _{H is used} in the above formula. This value can be fixed; but it can also be provided that D _H , when the driver his gaze from the front of the vehicle 11 lying roadway 25 turns away from the value d with the vehicle speed 11 decreasing to take into account the fact that the distance to an area of the traffic lane 25 . whose limitation the driver has not yet seen decreases with this speed.

An output of the processing unit 4 controls an actuator 18 , the Z. B. on a steering shaft 19 of the vehicle 11 attacks. The actuator 18 is pulsed controllable to when the steering correction δ _R exceeds a first limit, one or more times for a short time to generate a torque that is for the driver 13 at the steering wheel 20 is noticeable and acts in a direction in which the driver 13 the steering wheel 20 would have to turn to the vehicle 11 to keep safe on the lane. If the driver 13 This request follows and the yaw rate ΔΨ of the vehicle 11 changes, the steering correction δ _R falls below the limit again, and the processing unit 4 controls the actuator 18 not again.

If the driver does not react, it can be provided that the processing unit 4 when exceeding a second, higher limit of the steering correction δ _R again, then preferably generates stronger, torque pulses, or the generation of torque pulses can be continued as long as the steering correction δ _{R is} above the first limit.

It can also be provided that when a suitably set limit value of the steering correction δ _{R is} exceeded, the processing unit 4 the control of the steering of the vehicle 11 takes over, for. B. by opening a clutch 21 between steering wheel 20 and steering spindle 19 or by generating a torque by means of the actuator 18 , which is increased until the driver 13 on the steering wheel 20 applied torque is overcome and the steering wheel 20 is rotated according to the specified steering correction δ _R.

In a simplified embodiment, the camera monitors 8th the driver sensors 7 not the line of sight, only the position of the eyes 15 the driver 13 in the vehicle 11 , Knowing this position and the shape of a hood 22 of the vehicle is the processing unit 4 in the position, a line of sight 23 to calculate that from the eyes 15 the driver from the hood 22 grazing and the road surface 14 in front of the vehicle 11 at one point 24 at the distance d 'crosses. If the driver has a clear view and drives in a reclined position, the point of intersection lies 24 the line of sight 23 with the roadway 14 far from the vehicle 11 is removed, and a high value of d 'goes into setting the steering correction δ _R as D _H. When poor visibility the driver 13 forces to stretch in the seat or prevent to the lane 14 near the vehicle 11 to survey, then the line of sight 23 steeper, the distance d 'decreases, and the steering correction δ _R becomes larger. The control of the actuator 18 based on the steering correction δ _R as described above.

According to a further development are directional headlights 29 (S. 1 ) of the vehicle 11 via another actuator 28 (S. 2 ) to the processing unit 4 coupled to pivot the headlamps about a vertical yaw axis. An angle around which the direction of one of the headlights 29 generated beam 30 deviates from the x-axis, the sum of two contributions, in a conventional manner to the steering angle of the steerable wheels 31 of the vehicle 11 proportional contribution, as well as a steering correction δ _R proportional contribution ψ ', which causes the beam 30 not always on an area of the lane 25 is aligned to the vehicle 11 while maintaining the current steering angle is soon used, but is deflected sideways against this area in a direction in which the vehicle 11 should be steered to the lane 25 not to leave. This post ψ 'allows the headlamps 29 in the in 1 shown situation in which the wheels 31 are still oriented for straight ahead driving and the steering angle proportional contribution is thus still zero, the course of a leading curve of the lane 25 to follow. So can the processing unit 4 Show the driver in a confusing traffic situation a mobile way, without the need for the actuator 18 to intervene in the steering.

Since the contribution ψ 'is proportional to the steering correction δ _R , it automatically takes into account how far the driver is from the lane in front of him 25 overlooks, and points the driver all the more clearly to the side, the shorter the section of the lane overlooked by him 25 is.

Another actuator may be provided to the processing unit 4 to enable the headlights 29 also to pivot about the y-axis and so the distance in which the axis of the beam 30 the road crosses, the line of vision 12 respectively. 23 track the driver and thus preferably illuminate the area of the road in which the driver 11 or in which he should look in the case of a significantly different from zero steering correction δ _R to the vehicle 11 to direct there.

It should be understood that the foregoing detailed description and drawings, while indicating certain exemplary embodiments of the invention, are intended for purposes of illustration only and are not to be construed as limiting the scope of the invention. Various modifications of the described embodiments are possible without departing from the scope of the following claims and their equivalence range. In particular, go out of this Description and the figures also show features of the embodiments, which are not mentioned in the claims. Such features may also occur in combinations other than those specifically disclosed herein. Therefore, the fact that several such features are mentioned in the same sentence or in a different type of textual context does not justify the conclusion that they can occur only in the specific combination disclosed; instead, it is generally to be assumed that it is also possible to omit or modify individual ones of several such features, provided this does not call into question the functionality of the invention.

LIST OF REFERENCE NUMBERS

1

ambient sensor

2

camera

3

image evaluation

4

processing unit

5

speedometer

6

sensor

7

driver sensor

8th

camera

9

image evaluation

10

microprocessor system

11

vehicle

12

line of sight

13

driver

14

roadway

15

eye

16

intersection

17

Car navigation system

18

actuator

19

steering shaft

20

steering wheel

21

clutch

22

Engine Hood

23

line of sight

24

intersection

25

lane

26

lane boundary

27

lane boundary

28

actuator

29

headlights

30

beam

31

wheel

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102011087459 A1 [0002]

Claims (12)

Lane keeping assistance system for a vehicle with an environmental sensor system ( 1 ) for detecting the position of the vehicle ( 11 ) relative to a boundary of a lane traveled by the vehicle, a processing unit ( 4 ) for determining a to hold the vehicle ( 11 ) on the lane suitable steering correction (δ _R ) and a driver sensor system ( 7 ) for detecting the viewing direction ( 12 . 23 ) of the driver ( 13 ), the processing unit ( 4 ) to the driver sensor system ( 7 ) is coupled to the distance (d, d ') of an intersection ( 16 . 24 ), at which the viewing direction ( 12 . 23 ) of the driver ( 13 ) the surface ( 14 ) the lane crosses, from the vehicle ( 11 ) and the steering correction (δ _R ) at a small distance of the point of intersection ( 16 . 24 ) greater than at long distance. Lane keeping assistance system according to claim 1, wherein the processing unit ( 4 ) is configured to issue a warning when the steering correction (δ _R ) exceeds a first limit value. Lane keeping assistance system according to claim 1 or 2, wherein the processing unit ( 4 ), in the steering of the vehicle ( 11 ) to intervene when the steering correction (δ _R ) exceeds a second limit. Lane keeping assistance system according to one of the preceding claims, in which the driver sensor system ( 7 ) one on the eyes ( 15 ) of the driver ( 13 ) oriented camera ( 8th ). Lane keeping assistance system according to one of the preceding claims, in which the driver sensor system ( 7 ), the position of the driver's head ( 13 ) in the longitudinal direction of the vehicle ( 11 ) and the processing unit ( 4 ) is arranged to assume a shorter distance (d '), the farther forward in the vehicle ( 11 ) is the head. Lane keeping assistance system according to one of the preceding claims, in which the driver sensor system ( 7 ), the viewing direction ( 12 ) of the driver ( 13 ) in the azimuthal direction, and the processing unit ( 4 ) is set to, when the line of sight ( 12 ) from the direction of the lane ( 25 ) differs to assume a shorter distance (D _H ) than if the viewing direction ( 12 ) with the direction of the lane ( 25 ) matches. Lane keeping assistance system according to one of the preceding claims, in which the processing unit ( 4 ) to a directional headlight ( 29 ) is coupled to a beam ( 30 ) of the headlamp ( 29 ) to deflect a yaw axis (z) in the direction of steering correction (δ _R ). Lane keeping assistance system according to claim 7, wherein the deflection (ψ ') of the jet ( 30 ) at a short distance (d) of the point of intersection ( 16 ) is greater than at long distance (d). Lane keeping assistance system according to claim 7 or 8, wherein the jet ( 30 ) about a pitch axis (y) as a function of the distance (d) of the point of intersection ( 16 ) is pivotable. Lane keeping assistance system according to claim 9, wherein the jet ( 30 ), the shorter the distance (d) is, the more inclined downwards; Computer program product with program code means that enable a computer, at least as a processing unit ( 4 ) in a lane keeping assistance system according to any one of claims 1 to 10. Computer-readable medium on which program instructions are recorded that enable a computer as a processing unit ( 4 ) in a lane keeping assistance system according to any one of claims 1 to 10.

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