Method for operating a motor vehicle with a light marking for lateral guidance support and a detection of a lane, motor vehicle

Abstract

Method for operating a motor vehicle (100), wherein a light marking (1) with a left guide line (1.1) and a right guide line (1.2) is projected onto the ground in front of the motor vehicle (100) to assist in lateral guidance of the motor vehicle (100), wherein a lane (FS) is detected by a camera (2) of a driver assistance system (3), wherein a marking width (MB) between the left guide line (1.1) and the right guide line (1.2) is compared with a lane width (SB) of the detected lane (FS), wherein the projection of the light marking (1) is interrupted as soon as the marking width (MB) and the lane width (SB) differ by less than a minimum value.

Description

[0001] The present invention relates to a method for operating a motor vehicle with a light marking for lateral guidance support and detection of a lane, as well as to a motor vehicle.

[0002] To make road traffic safer and driving more comfortable, vehicles are increasingly being equipped with driver assistance systems. Such driver assistance systems can support the driver in making driving decisions, for example, by displaying previously recognized traffic signs on a screen, or relieve the driver of certain tasks, such as adaptive cruise control. Another function of such driver assistance systems is to monitor the driving situation and intervene in emergency situations, as is the case with emergency braking assistants, for example.

[0003] All driver assistance systems require data to be collected and processed in order to function. Data can be collected in a variety of ways. Radar, ultrasonic, and acceleration sensors are common. In addition, optical data, usually via a camera, is collected for many tasks to assist the driver.

[0004] State-of-the-art methods for lateral guidance support, such as those found in document DE 10 2006 048 503 A1, involve projecting light markings onto the road in front of the vehicle. These conveniently provide the driver with information about the path their vehicle will take in the current direction of travel, which is particularly helpful in confined and confusing situations, such as highway construction zones.

[0005] From the publication DE 10 2013 222 467 A1, it is known to project two guide lines in front of a motor vehicle. If the motor vehicle deviates from an ideal line, the guide line in the direction in which the motor vehicle deviates from the ideal line is illuminated.

[0006] What provides the driver with increased comfort, however, is detrimental to the optical sensors used to detect available lanes. Driver assistance systems are regularly confused by light markings when collecting data for lane departure warning systems. The light markings also recorded by the camera used to monitor lanes can be mistakenly interpreted as lane markings, which can lead to dangerous misjudgments by the driver assistance system.

[0007] It is therefore an object of the present invention to provide a method for operating a motor vehicle which does not have the disadvantages of the prior art described above, but rather enables the use of light markings and reduces the risk of misinterpretation of the light markings as road markings.

[0008] This object is achieved by a method for operating a motor vehicle, wherein a light marking with a left guide line and a right guide line is projected onto the ground in front of the motor vehicle to assist the lateral guidance of the motor vehicle, wherein a lane is detected by a camera of a driver assistance system, wherein a marking width between the left guide line and the right guide line is compared with a lane width of the detected lane, wherein the projection of the light marking is interrupted as soon as the marking width and the lane width differ by less than a minimum value.

[0009] The method according to the invention makes it possible to detect an irritation of the driver assistance system by comparing the marking width generated by the motor vehicle, which is thus fixed and known, with the optically determined lane width. This irritation can be remedied by interrupting the projection of the light marking. If the projection is interrupted, the lane can be re-detected without irritation. If this is the case, the projection is preferably continued.

[0010] Preferably, the left guide line and the right guide line are arranged parallel to each other in the direction of travel. It is conceivable that the left guide line is projected by a projection device in the left headlight or the left exterior mirror, and the right guide line is projected by a projection device in the right headlight or the right exterior mirror. Preferably, the marking width and the lane width are arranged orthogonally to the direction of travel.

[0011] Advantageous embodiments and further developments of the invention can be found in the dependent claims and the description with reference to the drawings.

[0012] According to a preferred embodiment of the invention, the minimum value is less than 50 cm, preferably less than 25 cm, and in particular less than 10 cm. This allows for early intervention if any disturbances occur during the optical detection of the lane.

[0013] According to a further preferred embodiment of the invention, the projection of the light marking is interrupted as soon as the marking width and the lane width are equal. If this is the case, there is a very high probability that an error has occurred in the lane detection and that the driver assistance system is confused by the optical detection of the light marking. This advantageously ensures that the light marking is only deactivated when there is actually an error.

[0014] According to a further preferred embodiment of the invention, the marking width and the lane width are compared at a distance of 1 m to 20 m, preferably 5 m to 15 m, from the motor vehicle in the direction of travel. This allows the influence of road surface irregularities on the comparison of lane width and marking width to be minimized.

[0015] According to a further preferred embodiment of the invention, the marking width and the lane width are compared along a comparison area in the direction of travel with a length of 1 m to 20 m, preferably 5 m to 15 m, and in particular approximately 10 m. Comparing the widths over an area, i.e. along a distance parallel to the direction of travel, enables a more precise statement as to whether the driver assistance system is being irritated by the light marking. Unnecessary masking of the light marking can thus be avoided. For this purpose, it is preferably provided that the comparison area is spaced from the motor vehicle by 1 m to 20 m, and preferably 5 m to 15 m, in the direction of travel.

[0016] According to a further preferred embodiment of the invention, the interruption of the projection is canceled after an interruption period, and the light marking is projected again, wherein the interruption period is preferably less than 1 second, particularly preferably less than 500 milliseconds, and in particular less than 100 milliseconds. This advantageously allows the light marking to be available again as quickly as possible. Within the interruption period, the driver assistance system has the opportunity to resolve the confusion and correctly detect the lane.

[0017] According to a further preferred embodiment of the invention, the projection is only interrupted when a lane keeping function of the driver assistance system is active. This prevents unnecessary interruption of the projection.

[0018] According to a further preferred embodiment of the invention, the lane keeping function is deactivated if no lane can be detected during the interruption of the projection. The lane keeping function is preferably deactivated if, during the interruption of the projection, no lane can be detected within a reorientation time, wherein the reorientation time is preferably less than 500 milliseconds. This prevents the light marking from being continuously interrupted when reorientation, i.e., correct detection of the lane by the driver assistance system, is not possible.

[0019] A further object of the invention for solving the problem formulated at the outset is a motor vehicle, comprising means for projecting a light marking with a left guide line and a right guide line for lateral guidance support of the motor vehicle onto the ground in front of the motor vehicle, a camera of a driver assistance system for detecting a lane, wherein the driver assistance system is configured to compare a marking width between the left guide line and the right guide line with a lane width of the detected lane and to interrupt the projection of the light marking as soon as the marking width and the lane width differ by less than a minimum value. The motor vehicle is preferably configured to be operated using a method according to the invention.

[0020] All details, features and advantages previously disclosed in connection with the method according to the invention also relate to the motor vehicle according to the invention.

[0021] Further details, features, and advantages of the invention will become apparent from the drawings and the following description of preferred embodiments with reference to the drawings. The drawings merely illustrate exemplary embodiments of the invention, which do not limit the inventive concept. Fig. 1 schematically illustrates a motor vehicle according to an exemplary embodiment of the present invention, which is operated with a method according to an exemplary embodiment of the present invention.

[0022] Fig.1 schematically illustrates a motor vehicle 100 according to an exemplary embodiment of the present invention, which is operated using a method according to an exemplary embodiment of the present invention. The motor vehicle 100 shown is traveling in the direction of travel FR on a road with a center line 5.1 and lane boundaries 5.2, of which only the right one is shown here.

[0023] In order to enable comfortable and safe driving of the motor vehicle 100, the motor vehicle 100 projects a light marking 1 with a left guide line 1.1 and a right guide line 1.2 onto the road in front of the motor vehicle 100 using projection means 4. The left guide line 1.1 and the right guide line 1.2 make it easier for the driver to estimate the path of the motor vehicle 100.

[0024] At the same time, a lane keeping function of a driver assistance system 3 is active. If, for example, due to a driver's inattention, the motor vehicle 100 threatens to leave the lane FS delimited by the center line 5.1 and the right lane boundary 5.2, the driver assistance system 3 intervenes by warning the driver and / or actively intervening in the steering.

[0025] It is also conceivable, of course, that the lane FS is delimited by the right lane boundary 5.2 and a left lane boundary (not shown). To detect the lane FS, the driver assistance system 3 has an optical camera 2, which detects the center line 5.1 and the right lane boundary 5.2, and thus the lane FS.

[0026] Under certain circumstances, the optical detection of the lane FS may be impaired due to the fact that the guide lines 1.1, 1.2 are misinterpreted as the center line 5.1 and / or the lane boundary 5.2 by the camera 2 or the driver assistance system 3. This confuses the driver assistance system 3, which can lead to dangerous misjudgments and, possibly, fatal steering interventions by the driver assistance system 3.

[0027] To prevent this, the marking width MB between the left guide line 1.1 and the right guide line 1.2 and the lane width SB of the lane FS are compared with each other during operation of the lane keeping function. The marking width MB is specified by the motor vehicle 100, while the lane width SB is optically determined by the driver assistance system 3 via the camera 2. If the lane width SB approaches the marking width MB and falls below a minimum value of, for example, 10 cm, or if the lane width SB and the marking width MB are even equal, there is a very high probability that the guide lines 1.1, 1.2 will be misinterpreted as the center line 5.1 and the lane boundary 5.2, and that the driver assistance system will be confused by the light marking 1. To end this situation, the projection of the light marking 1 is interrupted for a specific interruption time.During this interruption time, for example, less than 100 milliseconds, the driver assistance system 3 can reorient itself, resolve the confusion, and detect the correct lane based on the center line 5.1 and the lane markings 5.2. If this fails within a specified reorientation time, a corresponding warning can be issued to the driver, the lane keeping function is preferably deactivated, and the light marking 1 is projected back onto the road.

[0028] To enable a good comparison between the marking width MB and the lane width SB, the widths MB and SB are compared along a comparison area VG, which, for example, has a length of 10 m parallel to the direction of travel FR. The comparison of the widths MB and SB takes place at a distance A of 5 m to 15 m in front of the vehicle 100. List of reference symbols 1 light marking 1.1 left guideline 1.2 right guideline 2 cameras 3 Driver assistance system 4 Means of projection 5.1 Center line 5.2 Lane markings 100 motor vehicles A distance FR direction of travel FS lane MB marking width SB track width VG comparison range

Claims

[1] Method for operating a motor vehicle (100), wherein a light marking (1) with a left guide line (1.1) and a right guide line (1.2) is projected onto the ground in front of the motor vehicle (100) to assist in lateral guidance of the motor vehicle (100), wherein a lane (FS) is detected by a camera (2) of a driver assistance system (3), wherein a marking width (MB) between the left guide line (1.1) and the right guide line (1.2) is compared with a lane width (SB) of the detected lane (FS), wherein the projection of the light marking (1) is interrupted as soon as the marking width (MB) and the lane width (SB) differ by less than a minimum value. [2] Method according to claim 1, wherein the minimum value is less than 50 cm, preferably less than 25 cm and in particular less than 10 cm. [3] Method according to one of the preceding claims, wherein the projection of the light marking (1) is interrupted as soon as the marking width (MB) and the track width (SB) are equal. [4] Method according to one of the preceding claims, wherein the marking width (MB) and the lane width (SB) are compared at a distance (A) of 1 m to 20 m, preferably of 5 m to 15 m, from the motor vehicle (100) in the direction of travel (FR). [5] Method according to one of the preceding claims, wherein the marking width (MB) and the lane width (SB) are compared along a comparison area (VG) in the direction of travel (FR) with a length of 1 m to 20 m, preferably of 5 m to 15 and in particular of approximately 10 m. [6] Method according to claim 5, wherein the comparison area (VG) is spaced from the motor vehicle (100) by 1 m to 20 m and preferably 5 m to 15 m in the direction of travel (FR). [7] Method according to one of the preceding claims, wherein the interruption of the projection is canceled after an interruption time and the light marking (1) is projected again, wherein the interruption time is preferably less than 1 second, particularly preferably less than 500 milliseconds and in particular less than 100 milliseconds. [8] Method according to one of the preceding claims, wherein the projection is only interrupted when a lane keeping function of the driver assistance system (3) is active. [9] Method according to claim 8, wherein the lane keeping function is deactivated if no lane (FS) can be detected during the interruption of the projection, wherein the lane keeping function is preferably deactivated if no lane (FS) can be detected during the interruption of the projection within a reorientation time, wherein the reorientation time is preferably less than 100 milliseconds. [10] Motor vehicle (100), comprising means (4) for projecting a light marking (1) with a left guide line (1.1) and a right guide line (1.2) for supporting the lateral guidance of the motor vehicle (100) onto the ground in front of the motor vehicle (100), a camera (2) of a driver assistance system (3) for detecting a lane (FS), wherein the driver assistance system (3) is configured to compare a marking width (MB) between the left guide line (1.1) and the right guide line (1.2) with a lane width (SB) of the detected lane (FS) and to interrupt the projection of the light marking (1) as soon as the marking width (MB) and the lane width (SB) differ by less than a minimum value.

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