Method and device for projecting a temporary road marking onto a roadway

Abstract

Method for assisting a driver of a vehicle (A), comprising the steps: - Detecting at least one characteristic feature (M) for the formation of a lane (F) in a vehicle environment (U) of the vehicle (A) by means of a sensor system (20), wherein the at least one characteristic feature (M) is cars parked to the side or damage to the side of the roadway; - Determining a target position (S) of a temporary road marking (10) to be projected on the lane (F) based on at least one detected feature (M) of the vehicle environment (U) and a positioning specification for road markings (10) using a determination unit (30), wherein the roadway at the target position (S) has no visible or detectable permanent road marking (L); - Projecting the temporary road marking (10) onto the specified target position (S) of the roadway using a light-generating device (40); - Scanning of the projected temporary lane marking (10) by a driver assistance system of the vehicle (A), and - Assisting the driver through the driver assistance system depending on the scanned projected temporary lane markings.

Description

[0001] The present invention relates to a method for assisting a driver of a vehicle, particularly in a case where a roadway at a target position has no visible or detectable lane markings. Furthermore, the invention relates to a device for assisting a driver of a vehicle.

[0002] Modern headlight systems feature control units that allow the emitted light to be freely programmed and modulated, thus enabling any desired light distribution. Such headlight systems utilize special headlights that, for example, feature an LCD display as a bezel that can be controlled by the control unit. By specifically controlling the bezel, virtually any desired illumination of the areas in front of the headlight can be achieved. Individual sectors can, for example, be completely blanked out or illuminated only more dimly than others. Such headlight systems are also referred to as high-resolution or HD headlight systems due to their precise controllability of the illumination of specific areas.

[0003] Known adaptive headlight systems can be configured to control the illumination of areas arranged in front of the HD headlights in such a way that certain areas, such as oncoming vehicles, are not illuminated to prevent dazzling the drivers of these vehicles. The higher the resolution of the headlights, the more precisely certain areas can be masked out without negatively affecting the illumination of neighboring areas. Furthermore, such headlight systems can be configured to specifically illuminate existing lane markings to make them more clearly visible to the driver.

[0004] Furthermore, driver assistance systems, such as lane keeping assistants, are known. These support the driver in keeping the vehicle in their lane by issuing a warning signal, for example, if the vehicle is about to leave their lane. Such warning signals can be visual, e.g., via a multifunction display; acoustic, e.g., via a warning tone or a warning announcement; or haptic, e.g., via a vibration of the steering wheel. Therefore, known driver assistance systems incorporate appropriate sensors, such as a camera, to detect lane markings.

[0005] Driver assistance and headlight systems are known from the documents DE 10 2012 002 058 A1, DE 10 2011 081 394 B3, DE 10 2009 009 472 A1, DE 10 2005 051 049 A1, DE 101 34 594 A1, US 2014 / 0 267 415 A1 and DE 10 2013 021 587 A1.

[0006] Existing driver assistance systems have the disadvantage that they rely on the presence of permanent road markings. If permanent road markings are missing or obscured, e.g., in construction zones or due to wear or other environmental influences, the systems are unable to assist the driver in staying in their lane. On sections of the road where road markings would be required but are not present or detectable, targeted illumination or projection of temporary road markings using existing systems is not possible, as the permanent road marking to be highlighted is not detectable or present as a positioning reference for the temporary road marking.

[0007] It is therefore an object of the present invention to remedy, or at least partially remedy, the disadvantages of driver assistance systems described above. In particular, the object of the invention is to provide a method and a device for assisting a driver of a vehicle, which are designed in a particularly simple and cost-effective manner and assist the driver, particularly on roadways where permanent lane markings are not recognizable or detectable.

[0008] The above object is achieved by the claims. In particular, the object is achieved by a method for assisting a driver of a vehicle, wherein the roadway at a desired position has no visible or detectable permanent road marking, having the features of independent claim 1. Furthermore, the object is achieved by a vehicle assistance system for a vehicle having the features of the independent claim 8. Further features and details of the invention emerge from the subclaims, the description and the drawings. Features and details described in connection with the method according to the invention naturally also apply in connection with the device according to the invention for projecting a temporary road marking and vice versa, so that with regard to the disclosure of the individual aspects of the invention, reciprocal reference is or can always be made.

[0009] According to a first aspect of the invention, the object is achieved by a method for assisting a driver of a vehicle (A). The method comprises the following steps: - detecting at least one feature in the vehicle environment of the vehicle that is characteristic of the formation of a lane by means of a sensor system, wherein laterally parked cars or lateral roadway damage are used as the at least one characteristic feature; - Determining a target position of a temporary lane marking to be projected on the basis of the at least one detected feature of the vehicle's surroundings and a positioning specification for lane markings by means of a determination unit, wherein the roadway at the target position has no visible or detectable permanent lane marking; - Projecting the temporary road marking onto the specified target position of the roadway by means of a light generating device; - scanning the projected temporary lane marking (10) by a driver assistance system of the vehicle; and - Assistance of the driver by the driver assistance system depending on the scanned projected temporary lane marking.

[0010] A roadway can have multiple lanes, with a lane designating an area of ​​the roadway intended for use by a vehicle. Roadways normally have permanent road markings, e.g., to separate multiple lanes from one another. A permanent road marking, within the meaning of the invention, is a road marking made of a material arranged on and / or in the roadway. Permanent road markings can, for example, be printed, glued, painted, or incorporated into the roadway. A permanent road marking can, for example, be a solid line, two parallel lines, a dashed line, etc.

[0011] An invisible or undetectable permanent road marking is, for example, a permanent road marking that is concealed, e.g., under dirt, snow, or leaves. A invisible or undetectable permanent road marking, within the meaning of the invention, also includes a missing permanent road marking at a location where a permanent road marking would normally be located.

[0012] A temporary road marking, in the sense of the invention, is a road marking that is projected onto the roadway for only a short period of time, preferably for the period during which the temporary road marking is within the field of vision of the car driver. For a vehicle traveling in the direction of travel, the temporary road marking is preferably generated in such a way that it is extended in the direction of travel at an end remote from the vehicle and simultaneously shortened at an end adjacent to the vehicle. Thus, it appears to the driver as if the temporary road marking were moving with the vehicle, adapting accordingly to the course of the lane, e.g., when cornering.A temporary road marking may correspond or substantially correspond to a section of a permanent road marking, or it may be provided that the temporary road marking has a different width and / or shape than a permanent road marking.

[0013] When detecting the characteristic features in the vehicle's surroundings, the sensor system preferably does not detect a permanent road marking, even if it is present. The method is designed such that, based on other characteristic vehicle surroundings features and positioning specifications for road markings, the determination unit determines, in particular calculates, a target position of the temporary road marking to be projected, and then the vehicle's light-generating device projects the determined temporary road marking onto the determined target position of the roadway.

[0014] This means that the temporary road marking is projected onto a desired position on the road. The desired position refers to a position or area / boundary at which a temporary road marking is helpful for the driver to drive safely on the road, preferably in their lane. The desired position may deviate from an actual position at which an invisible or undetectable permanent road marking is arranged or where a permanent road marking should be arranged. This is due in particular to the fact that the desired position is determined by means of the determination unit. According to the invention, detectable characteristic features such as cars parked to the side or damage to the roadway to the side are used to form the lane; these characteristics cause the desired position to deviate from the actual position.Ideally, the temporary road marking to be projected by the determination unit is identical to an existing permanent road marking or is projected in close proximity to it. In addition to the recorded characteristic environmental features, the positioning specifications available to the determination unit are crucial for this.

[0015] The detection of at least one feature in the vehicle environment that is characteristic for the formation of the lane is carried out by means of a sensor system, such as a camera and / or a radar and / or a lidar. The formation of a lane is defined, for example, by a lane width, a position of the lane on the roadway and a course of the lane. A characteristic feature for the formation of the lane is, for example, an object or a series of objects that can be used to determine the formation of the lane. A characteristic feature is, for example, a patch of turf at the edge of the roadway. When determining a characteristic feature, a position of the turf relative to the vehicle or the light generating device can therefore be determined. Other characteristic features are, for example,The position of delineators, guardrails, signs, streetlights, houses, cars, especially parked cars, a seam edge of a road surface running in the direction of travel, or the position of permanent pavement markings that are not located in an area around the nominal position of the temporary pavement marking, such as a lane edge marking that is spaced from the vehicle's lane or that is located on an opposite side of the car relative to the nominal position. "Position" here refers to a position relative to the lane.

[0016] The target position is determined by the determination unit based on the characteristic feature, e.g., the position of the guardrail relative to the vehicle, and the positioning specification. The relative position of the temporary road marking to the vehicle can be determined from the relative position of the characteristic feature to the vehicle and a positioning specification of a characteristic feature relative to the target position of the temporary road marking. Since the target position is determined based on characteristic features that differ from the position of the non-existent or undetectable permanent road marking, it may happen that the determined target position is laterally offset from the undetectable or non-existent permanent road marking. This is not a problem, since a sufficiently accurate target position can be determined using the characteristic features.

[0017] A positioning specification is a specification that defines the relative position of a target position to a characteristic feature. For example, a positioning specification specifies how far a lane edge marking or a lane marking between a right-hand lane and an emergency lane on a motorway must be from a guardrail or the edge of the road. Other positioning specifications specify the distance of the target position to, for example, parked cars, the curb, signs, lampposts, houses, the edge of the road, potholes on the side of the road, or delineator posts. Static and dynamic positioning specifications can be provided. A static positioning specification is a standard specification that is used in operation on a road with a standard design. On such roads, the relative positions of the lane to characteristic features are predetermined.With a dynamic positioning specification, however, location-specific features, such as a particularly wide or narrow road, are taken into account. For dynamic positioning specifications, for example, existing road markings are compared with other characteristic features of the vehicle's surroundings, and any deviations from the static positioning specifications determined from this are saved as dynamic positioning specifications. Thus, if a road marking is no longer visible, detectable, or present, a temporary road marking can be projected to a corresponding target position, even on roads with non-standard layouts. For example, a positioning specification can be a distance specification to a characteristic feature.For example, if a guardrail is detected as a characteristic feature by the sensor system, the determination unit knows that a distance of 1.2 m, for example, has been specified as the positioning specification for guardrails. This means that the determination unit determines the temporary road marking based on the characteristic features detected by the sensor system and the positioning specification specified for the respective characteristic features. This temporary marking is then projected by the light generation device into the field of vision of the vehicle driver, specifically onto the roadway.

[0018] This means that the temporary road marking is projected onto the specific target position on the roadway using a light-generating device. A light-generating device, within the meaning of the invention, is a device for generating a defined light distribution. A light-generating device can, for example, comprise a headlight, such as a high-resolution headlight (HD headlight), or a laser. Furthermore, according to the invention, a light-generating device can comprise a diaphragm and / or a lens optic for generating the defined light distribution.

[0019] The method according to the invention has the advantage over known methods for illuminating road markings that it enables the projection of temporary road lines at locations that do not have permanent road markings or at least where no permanent road marking is visible or detectable. For this purpose, information from the vehicle's surroundings is acquired using simple means and used to determine the target position of the temporary road marking. A further advantage is that, using the method according to the invention, conventional driver assistance systems based on scanning permanent road markings can also be used on roadways where a permanent road marking cannot be scanned by the driver assistance system, for example because it is not present or is obscured. The conventional driver assistance system then scans the projected temporary road marking and thus effectively assists the driver.

[0020] Preferably, the sensors detect several different features in the vehicle's surroundings that are characteristic of the lane formation. This has the advantage that the target position can be determined even if a specific characteristic feature is missing, e.g., if a guardrail is missing or broken.

[0021] Further preferably, a specific target position is determined for each of several different characteristic features of the vehicle's surroundings, and the target position of the temporary road marking to be projected is determined from the several specific target positions. The characteristic features are preferably prioritized so that a parked car or a side pothole is given higher priority than a curb or a guide post. When determining a central road marking and a guardrail, the target position can be determined, for example, by averaging the specific target positions. This has the advantage that the method can react flexibly to changes in the vehicle's surroundings and adapt the projection of the temporary road marking accordingly.

[0022] It is preferred that the characteristic feature detected is the position of a road edge, a lateral road boundary element—such as a guardrail, a delineator post, a sign, a lamppost, or a curb—a position of a seam edge of a road surface running longitudinally along the roadway, a side edge of the roadway, a parked car, or a permanent road marking that is not positioned at the desired position. Such characteristic features are easily detectable by the sensors and provide reliable information about the lane configuration. Houses or trees can also be detected as characteristic features.

[0023] According to a preferred embodiment of the method, the detection of at least one characteristic feature for a lane formation is carried out repeatedly as the vehicle moves in one direction of travel. The at least one characteristic feature for a lane formation detected consecutively in the direction of travel is compared with each other and adjusted by interpolation, with the adjusted characteristic features being used to determine the target position. An irregular course of a road edge or missing road markings can be easily compensated for in this way. Likewise, different positioning specifications can be interpolated to determine the target position of the temporary road marking.

[0024] It can be provided that only characteristic features which are arranged laterally offset in the direction of travel of the vehicle from an area surrounding the TARGET position are used to determine the TARGET position. An area surrounding the TARGET position is an area that can be pre-determined using simple means and in which a permanent road marking should be arranged in order to correctly identify the lane. If, for example, a road marking between two lanes or at the edge of the road is missing or not visible, such an area surrounding the TARGET position can be easily determined. The area must be selected to be large enough that the TARGET position is always located within the area and small enough that as many characteristic features as possible that are located outside the area can be recorded.To determine the area, it may be provided to detect a characteristic feature that is definitely outside the area, such as another permanent road marking, delineator posts, guard rails, etc., and to determine the area using the positioning specification.

[0025] Preferably, a position of the vehicle is determined, a deviation of the at least one characteristic feature from map data corresponding to the determined position of the vehicle is determined, and the target position is adjusted based on the deviation. The vehicle's position is preferably determined using a GPS receiver. The map data preferably contains information about the layout of the roadway, such as the roadway width, the location and layout of the lanes, and the course of the roadway or lanes. This improves the accuracy of determining the target position.

[0026] According to a second aspect of the invention, the object is achieved by a vehicle assistance system for a vehicle. The vehicle assistance system comprises a driver assistance system for assisting a driver of the vehicle and a device for projecting a temporary lane marking onto a target position of a roadway. The device comprises a sensor system, a determination unit, and a light-generating device. The sensor system is designed to detect at least one feature in the vehicle environment of a vehicle that is characteristic of the formation of the lane. The determination unit is designed to determine the target position of the temporary lane marking to be projected based on the at least one detected characteristic feature. The light-generating device is designed to project the temporary lane marking onto the determined target position of the roadway.Furthermore, the determination unit is configured to determine the target position of the road marking to be generated based on the at least one characteristic feature detected by the sensor system and a positioning specification for road markings, even if no permanent road marking is visible or detectable at the target position. The sensor system is preferably configured to detect characteristic features in a detection area that extends across the entire road width. According to the invention, the vehicle assistance system is configured to carry out a method according to the invention.

[0027] The vehicle assistance system according to the invention has the advantage that a temporary road marking can be projected onto a target position using simple means even if no permanent road marking is visible or detectable at the target position.

[0028] In an advantageous embodiment of the invention, the sensor system comprises a camera and / or a radar and / or a lidar. Using such a sensor system, a multitude of different characteristic features can be reliably detected.

[0029] Further advantages, features, and details of the invention will become apparent from the following description, which describes embodiments of the invention in detail with reference to the drawings. The features mentioned in the claims and in the description may be essential to the invention individually or in any combination. Elements with the same function and mode of operation are provided with the same reference numerals in the individual figures. They schematically show: Fig. 1 a plan view of a vehicle with a device according to the invention on a roadway during the detection process, Fig. 2 the top view Fig. 1 during the determination process, Fig. 3 the top view Fig. 1 during the projection process and Fig. 4 a plan view of a preferred embodiment of a device according to the invention.

[0030] In Fig. 1 shows a plan view of a vehicle A on a lane F of a roadway. The vehicle A has a device 100 according to the invention for projecting a temporary road marking 10. The roadway has a permanent road marking L at an upper edge region in this illustration, which can be detected by the device 100 as a characteristic feature of the formation of the lane F. In a lower edge region in this illustration, no road marking L is present. Thus, an area B is determined in which the road marking L is missing and a DESIRED position S for a temporary road marking 10 (cf. Fig. 3) is to be arranged.

[0031] A sensor system 20 (cf. Fig. 4) of the device 100 carries out a detection process according to the method according to the invention. A detection area X is schematically shown as a hatched area and is formed in front of the vehicle A in the direction of travel FR of the vehicle A. Characteristic features M arranged in the detection area X, such as a guide post P, a road edge R and the permanent road marking L arranged outside the area B, are detected by the device 100 in this example. Detection of characteristic features M arranged in the area B is not necessary to determine the formation of the lane F, since sufficient other characteristic features M can already be detected outside the area B.

[0032] Fig. 2 shows the top view from Fig. 1, whereby a determination unit 30 (cf. Fig. 4) the device 100 performs a determination process according to the method according to the invention. During the determination process, a specific target position S1, S2 is preferably determined for each different characteristic feature M using a positioning specification. In this example, the determination unit 30 has determined two specific target positions S1, S2, each represented by a dashed line. The first specific target position S1 is determined, for example, using the detected guide post L and the corresponding positioning specification, and the second specific target position S2 is determined, for example, using the detected road edge R and the corresponding positioning specification.By analyzing the recorded characteristic features M, for example, to determine any priorities of the characteristic features M, the target position S shown as a hatched line is determined from the specific target positions S1, S2. A non-visible permanent road marking I is shown as a dashed line in area B. In this example, the determined target position lies directly on the non-visible permanent road marking.

[0033] In Fig. 3 is the top view from Fig. 1, wherein a light generating device 40 (cf. Fig. 4) the device 100 carries out a projection process according to the method according to the invention. In this example, the light generating device 40 designed as an HD headlight generates an illumination area Z which extends in the direction of travel FR in front of the vehicle A across the entire width of the road. The illumination area Z corresponds, for example, essentially to an asymmetrical low beam, wherein a temporary road marking 10, shown in dashed lines in this drawing, is additionally projected onto the desired position S. In this example, a width of the projected, temporary road marking 10 corresponds to a width of the invisible permanent road marking I or the permanent road marking L in the upper edge area. According to the invention, the width of the projected, temporary road marking 10 can also be wider or narrower than the width of the invisible permanent road marking I orthe permanent road marking L in the upper edge area.

[0034] Fig. 4 schematically shows a preferred embodiment of a device 100 according to the invention. The device 100 has a sensor system 20, a determination unit 30, and a light generation unit 40. In this embodiment, the sensor system 20 has a camera 50, a radar 60, and a lidar 70 as sensor elements for detecting characteristic features M of the lane F in the vehicle environment U. Of course, the invention can also provide for the sensor system 20 to have fewer sensor elements. A particularly preferred sensor system has a camera 50 and a lidar 70. List of reference symbols 10 temporary road markings 20 Sensor technology 30 Determination unit 40 Light generating device 50 Camera 60 radars 70 Lidar 100 device A vehicle AM adapted characteristic feature B area F lane FR direction of travel I non-visible permanent road marking L permanent road marking M characteristic feature P Delineator posts U Vehicle environment R roadside S Target position S1, S2 specific target position X Detection range Z illumination area

Claims

[1] Method for assisting a driver of a vehicle (A), comprising the steps: - detecting at least one feature (M) characteristic of the formation of a lane (F) in a vehicle environment (U) of the vehicle (A) by means of a sensor system (20), wherein laterally parked cars or lateral roadway damage are used as the at least one characteristic feature (M); - Determining a target position (S) of a temporary road marking (10) of the lane (F) to be projected on the basis of the at least one detected feature (M) of the vehicle surroundings (U) and a positioning specification for road markings (10) by means of a determination unit (30), wherein the road at the target position (S) has no visible or detectable permanent road marking (L); - Projecting the temporary road marking (10) onto the determined target position (S) of the road by means of a light generating device (40); - scanning the projected temporary lane marking (10) by a driver assistance system of the vehicle (A), and - Assistance of the driver by the driver assistance system depending on the scanned projected temporary lane marking. [2] Method according to claim 1, characterized by that several different features (M) characteristic of the formation of the lane (F) are recorded in the vehicle environment (U). [3] Method according to claim 2, characterized by that for several different characteristic features (M) of the vehicle environment (U) a specific target position (S1, S2) is determined and from the several specific target positions (S1, S2) the target position (S) of the temporary road marking (10) to be projected is determined. [4] Method according to one of the preceding claims, characterized bythat a position of a road edge (R), a lateral road boundary means, a position of a seam edge of a road surface running in the longitudinal direction of the road, a side edge of the road, a parked car or a permanent road marking (L) which is not formed on the desired position (S) is detected as a characteristic feature (M). [5] Method according to one of the preceding claims, characterized by that the detection of the at least one feature (M) characteristic of a formation of the lane (F) is carried out repeatedly when the vehicle (A) is moving in a direction of travel (FR), wherein the at least one feature (M) characteristic of a formation of the lane (F) detected one after the other in the direction of travel (FR) are compared with one another and adapted by interpolation, wherein the adapted characteristic features (AM) are used to determine the desired position (S). [6] Method according to one of the preceding claims, characterized by that only characteristic features (M) are used to determine the target position (S) which are arranged laterally offset in the direction of travel (FR) of the vehicle (A) from an area (B) surrounding the target position (S). [7] Method according to one of the preceding claims, characterized by that a position of the vehicle (A) is determined, a deviation of the at least one characteristic feature (M) from map data corresponding to the determined position of the vehicle (A) is determined and the desired position (S) is adjusted on the basis of the deviation. [8] Vehicle assistance system for a vehicle (A), comprising a driver assistance system for assisting a driver of the vehicle (A) and a device (100) for projecting a temporary road marking (10) of a lane (F) onto a target position (S) of a roadway, comprising a sensor system (20) for detecting at least one feature (M) characteristic of the formation of the lane (F) in a vehicle environment (U) of a vehicle (A), a determination unit (30) for determining the target position (S) of the temporary road marking (10) of the lane (F) to be projected on the basis of the at least one detected characteristic feature (M), and a light generation device (40) for projecting the temporary road marking (10) onto the determined target position (S), characterized byin that the determination unit (30) is designed to determine the desired position (S) of the road marking (10) to be generated on the basis of the at least one characteristic feature (M) detected by the sensor system (20) and a positioning specification for road markings (10), even if no permanent road marking (10) is visible or detectable at the desired position (S), wherein the vehicle assistance system is designed to carry out a method according to one of claims 1 to 7. [9] Vehicle assistance system according to claim 8, characterized by that the sensor system (20) comprises a camera (50) and / or a radar (60) and / or a lidar (70).

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