Method for monitoring whether a vehicle has exceeded the boundaries of a zone in which the vehicle may travel and driver assistance system

Abstract

The invention relates to a computer-implemented method for monitoring whether a vehicle (1) moving along a track (T) crosses the boundaries of a zone in which the vehicle (1) may travel, by determining the direction of rotation.

Description

[Technical field]

[0001] The present invention relates to the field of driver assistance systems for vehicles, in particular to a robust method for monitoring whether a vehicle guided by a driver assistance system exceeds the boundaries of an allowed driving zone when traveling along a trajectory. [Background technology]

[0002] Driver assistance systems for vehicles are generally known. Distance-based methods are also known, which involve checking whether a vehicle moved on a track maintains a certain distance from the boundary of the drivable area along the entire path of movement represented by the track. This is done taking into account the vehicle geometry, i.e. in particular the surface area generated by projecting the body contour onto the road.

[0003] There are also known methods which involve checking whether an intersection occurs between the vehicle's path, i.e. the area covered by the projection of the vehicle's body contour onto the road as the vehicle moves along the trajectory, and the boundary of the drivable area, i.e. whether the path crosses the boundary of the drivable area. In the known methods, the intersection points with the boundary of the drivable area have to be calculated.

[0004] The problem with the known method is that in order to determine the distance of the vehicle from the boundary line of the driveable area or the intersection point of a section of the body contour with the boundary line, a system of equations must be solved in each case, which results in a very high computational load. Moreover, it is not always possible to guarantee that the solution of the system of equations leads to a realistic solution. If no realistic solution is found, further checks must be performed.

[0005] The document China Patent Application Publication No. 102295004A discloses a method for lane departure warning, which includes the following steps: providing state information and environment information of current vehicle motion by vehicle sensors; and predicting the lane by a driving behavior model of a human driver, in which the combination of the kinematic characteristics and the motion model predicts the vehicle's possible lane area in a certain period of time in the future, which involves determining lane departure warning, and the relative relationship between the calculation time from the vehicle's possible driving lane to the detection point range on the driving lane marking line and the preset threshold time is regarded as an indicator of lane departure warning, thereby analyzing the vehicle's movement safety.

[0006] Document US 2012 / 0212612 A1 discloses a lane departure warning device which issues a warning signal upon detecting a vehicle deviating from its lane and which estimates lane markings in the absence of them.

[0007] The document Korean Patent Publication No. 101406316B1 teaches a device and method for detecting lanes, in which a warning zone within the lane is indicated based on the detected lane, and a warning is issued when the vehicle leaves this zone.

[0008] The paper "A video-based lane keeping assistant" by Risack, R., N. Mohler and W. Enkelmann, Proceedings of the IEEE intelligent vehicles symposium 2000 (Cat. No. 00TH8511), teaches various methods by which lane departure can be detected. One of these methods is to calculate the "time to lane crossing" based on the current trajectory and driving dynamics. Various driving dynamics models are used in the calculation, and the intersection of the driving dynamics curve with the lane markings is calculated here. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] China Patent Application Publication No. 102295004A [Patent Document 2] Reference: U.S. Patent Application Publication No. 2012 / 0212612A1 [Patent Document 3] Korean Patent No. 101406316B1 [Non-patent literature]

[0010] [Non-Patent Document 1] Risack, R., N. Mohler and W. Enkelmann, “A video-based lane keeping assistant” Proceedings of the IEEE intelligent vehicles symposium 2000 (Cat.No.00TH8511) Summary of the Invention [Problem to be solved by the invention]

[0011] In view of the above, an object of the present invention is to provide a method that enables reliable checking, with a small calculation load, as to whether or not a boundary of a drivable area has been crossed. [Means for solving the problem]

[0012] This object is achieved by a method having the features of independent claim 1. The dependent claims relate to preferred embodiments. Equivalent independent claim 8 relates to a driver assistance system designed to check whether a boundary of a driveable area is exceeded.

[0013] According to a first aspect, a method for checking whether a vehicle has exceeded a boundary of a driveable area is disclosed, the vehicle comprising a driver assistance system designed to move the vehicle along a track in an automatic or partially automatic manner, the driver assistance system being further configured to execute the checking method comprising the following steps:

[0014] First, information regarding at least one boundary of the drivable area is received. Here, the drivable area is defined in particular by at least one boundary, particularly preferably a left and a right boundary that are spaced apart from each other and that define, for example, a lane. The information can be provided by an environment detection unit of the vehicle, which creates a model of the surrounding environment surrounding the vehicle. By way of example, the boundary can identify a boundary in free space, in particular defining a lane along which the vehicle is travelling. As an alternative, the boundary can also characterize surrounding objects in the environment of the vehicle.

[0015] Preferably, at least one boundary line is defined by a polyline consisting of a number of points, i.e. a number of straight lines, each straight line extending between two adjacent points. Alternatively, the boundary line may be formed by a continuous line.

[0016] Furthermore, information is received about the path of the vehicle, which is in particular the area covered by the projection of the vehicle body contour onto the road when traveling along the track, in other words, the path is in particular a tubular area having a width at least equal to the vehicle width (or larger if a safety margin is incorporated).

[0017] A first and a second point are selected on at least one boundary line of the driveable area. When information about two boundary lines, in particular the left and right boundary lines of the driveable area, is received, preferably a first point and a second point are selected on the two boundary lines, respectively, where the first point is behind the second point on the same boundary line in the direction of movement of the vehicle. These points thus define a section of at least one boundary line, for which a check is made as to whether the boundary line has been crossed when traveling along the track.

[0018] At least one or exactly one third point on the edge of the path of the vehicle is also identified. The path of the method can be defined either by a continuous line or by a number of body contours positioned at different positions along the trajectory. The body contour can be formed, for example, by a polygon, in particular a rectangle, which at least approximately represents the body contour when the vehicle is viewed from above. In order to obtain a safety margin, the body contour can be selected to be larger than the actual body contour.

[0019] The position of at least one or exactly one third point is then ascertained with respect to a line between the first and second points on the same boundary line, at least intermittently, in particular by performing a determination of the rotation direction for at least the third point. Furthermore, it is checked whether the determined rotation direction is clockwise or counterclockwise, i.e. three points are connected by a polyline, two of which are on the same boundary line and one point represents a point on the vehicle's path. The check of the rotation direction is generated in particular when the polyline is traced such that a path between two points on the boundary line of the driveable area is traced in the direction of movement.

[0020] The next step is to check, based on the checked direction of rotation for at least the third point, whether the vehicle has crossed the boundary of the driveable area.

[0021] This method has the technical advantage that the checking method based on the direction of rotation allows for a technically simple check with little computational load, since the checking method is point-based, which means that computationally efficient vector calculation methods can be used and therefore no computationally intensive equation systems need to be solved, and furthermore, the checking method makes it possible to identify whether the vehicle has already completely left the drivable area, which increases the safety of the checking method.

[0022] According to an exemplary embodiment, the rotation direction is determined by following a polyline formed starting from the first point, passing through the second point, to the third point, and determining a rotation direction for the third point. A discrepancy between the determined rotation direction and an expected rotation direction indicates, among other things, a boundary violation.

[0023] According to one exemplary embodiment, the third point is a vehicle vertex of a polygon, in particular a quadrilateral, in particular a rectangle, which reproduces the body contour of the vehicle. The body contour is thus approximated in particular by a rectangle having four corners.

[0024] According to one exemplary embodiment, at least or exactly one boundary line of the drivable area is approximated by a number of points spaced apart from one another, and pairs of boundary line points are selected in turn as first and second points and used to verify the direction of rotation and to check whether the boundary line of the drivable area is crossed, thereby making it possible to iteratively check whether the drivable area is crossed without a system of equations, based only on the pairs of boundary line points.

[0025] According to one exemplary embodiment, the drivable area has left and right boundary lines that are spaced apart from each other and define a lane. The vehicle body contour is approximated by a polygon with two left vehicle vertices and two right vehicle vertices. The position of the at least two left vehicle vertices relative to a line between a first and a second point located on the left boundary line is checked at least intermittently for the left vehicle vertices. Furthermore, for the at least two left vehicle vertices, the determination of the direction of rotation is preferably performed by determining a direction of rotation for each left vehicle vertex, i.e. when following a polyline formed in each case starting from the first point and via the second point to the respective vehicle vertex. Thus, at least two directions of rotation are determined in particular. Then, it is checked whether the determined direction of rotation is clockwise. Based on the checked direction of rotation, it is checked whether the vehicle has crossed the left boundary line of the drivable area. Thus, the method can be advantageously applied with a lower computational load to realize compliance with the left boundary line of a predefined lane.

[0026] According to one exemplary embodiment, the drivable area has left and right borders that are spaced apart from each other and define a lane. The vehicle body contour is approximated by a polygon with two left vehicle vertices and two right vehicle vertices. A position relative to a line between a first and a second point on the right border is checked for the right vehicle vertex. Furthermore, for the two right vehicle vertices, the determination of the direction of rotation is preferably performed by determining a direction of rotation for each right vehicle vertex, i.e. when following a polyline formed in each case starting from the first point and via the second point to the respective vehicle vertex. Thus, at least two directions of rotation are determined in particular. Then, it is checked whether the determined direction of rotation is clockwise. Based on the checked direction of rotation, it is checked whether the vehicle has crossed the right border of the drivable area. Thus, the method can be advantageously applied with a lower computational load to realize compliance with the right border of a predefined lane.

[0027] According to a preferred further development, the determination of the direction of rotation and the checking of the direction of rotation are carried out for at least two vehicle vertices, particularly preferably for all vehicle vertices which represent the body contour.

[0028] According to one exemplary embodiment, the boundaries of the driveable area relate to the boundaries of lanes or road boundaries.

[0029] A further subject of the invention relates to a driver assistance system designed to check whether the vehicle has exceeded the boundaries of a driving area, said driver assistance system comprising a number of, in particular at least two, sensors distributed around the vehicle and a computing unit for processing the information provided by the sensors. - receiving information about at least one boundary of a drivable area; - receiving information about a path of the vehicle, the path being the area covered by a projection of a vehicle body contour onto a road when traveling along a trajectory, - selecting first and second points on at least one boundary line of the drivable area, the first point being behind the second point in a direction of movement of the vehicle; - defining at least or exactly one third point located on the vehicle, - checking the position of at least a third point relative to the line between the first and second points to verify that a determination of a rotation direction is made for the at least third point and to check whether the determined rotation direction is a clockwise or counterclockwise direction; - determining whether the vehicle has crossed at least one boundary line of the drivable area based on the verified rotation direction of at least a third point; The present invention is configured to:

[0030] For the purposes of the present invention, the terms "approximately", "substantially" or "about" refer to deviations of ±10%, preferably ±5% from the respective exact value and / or variations that are not significant for functionality.

[0031] Developments, advantages and possible applications of the invention can also be seen from the following description of exemplary embodiments and from the drawings, in which all the features described and / or shown are essentially subject matter of the invention in themselves or in any desired combination, regardless of the combination of these features in the claims or in the claims which depend thereon. The subject matter of the claims also becomes part of this description.

[0032] In the following, the invention is explained in more detail using exemplary embodiments and with reference to the figures. [Brief description of the drawings]

[0033] [Figure 1] 1 shows a schematic plan view of a vehicle with a driver assistance system including a number of sensors and a computing unit by way of example. [Diagram 2] Here are examples of different configurations of points A, B, and C that show the resulting rotation directions given a rotation direction of the points. [Diagram 3] An example is shown of a vehicle moving along a trajectory using a pair of boundaries defining a lane, and an exemplary application of a rotation direction based method for checking whether a lane boundary has been crossed. [Figure 4] An example is shown of a vehicle moving along a lane based on its trajectory, crossing the left boundary of the lane. [Diagram 5] 10 is a flowchart showing the steps of a method for checking whether a boundary of a drivable area has been exceeded. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0034] 1 shows, by way of example, a schematic plan view of a vehicle 1 with a driver assistance system for performing automated or partially automated driving operations. The driver assistance system may in particular be designed to recognize areas in which the vehicle 1 can travel automatically or partially automatically and to control the vehicle 1 so that it does not go beyond the boundaries of the drivable area. By way of example, the drivable area may be a lane with left and right borders. Alternatively, the drivable area may also be limited by one or more surrounding objects with which collisions must be avoided.

[0035] The vehicle 1 has a number of sensors 2 by means of which the surrounding area of ​​the vehicle 1 can be detected. The sensors 2 are coupled to a computation unit 3 of the driver assistance system, which processes the sensor information and provides information about at least one boundary of the drivable area. This surrounding detection gives the driver assistance system the ability to identify local areas in which the vehicle 1 can be guided without collisions.

[0036] The driver assistance system is further designed to determine the trajectory along which the vehicle 1 is moved during an autonomous or partially autonomous driving maneuver. When traveling through the trajectory, the vehicle is moved along a travel path. The travel path is given by the area covered or temporarily occupied by the body when the vehicle is moving. The vehicle has, for example, a peripheral contour of the body, which is obtained when the vehicle 1 is looked down from above, i.e. in a bird's-eye view. The projection of this body contour onto the road, directed vertically downwards, defines the area of ​​the road occupied by the vehicle 1. To be able to move the vehicle 1 without collisions, this area must necessarily be free for travel. The travel path is therefore tubular and has a width at least equal to the width of the body contour. To increase the safety of the method, the travel path can be designed to be wider than the width of the vehicle.

[0037] To identify whether the vehicle 1 has crossed the boundary of the driveable area, a checking method based on the direction of rotation can be applied.

[0038] FIG. 2 shows two possibilities as to how the three points A, B and C can be located.

[0039] By way of example, the line between the first point B and the second point C forms a section of the boundary of the drivable area. By way of example, the third point A can be a vertex of the body contour of the vehicle 1. The points A, B and C form a triangle, usually a polygon. When tracing a polyline along the points in a given order, for example from point B via point C to point A, it is possible to ascertain the positional information of point A relative to the line between points B and C. If a clockwise rotation direction occurs when tracing the polyline, it can be concluded that point A is on the right side of the line BC. In the opposite case, if the rotation direction becomes counterclockwise when tracing the polyline, it can be concluded that point A is on the left side of the line BC (right diagram of FIG. 2).

[0040] Fig. 3 shows one exemplary application of the above-mentioned method, where a vehicle 1 is moved on a trajectory T in a moving direction TD in a lane defined by a left boundary line G1 and a right boundary line G2. The boundaries G1, G2 can be reproduced by discrete points spaced apart from each other. In the exemplary embodiment according to Fig. 3, points B and C are two points of the left boundary line G1 and points B' and C' are two points of the right boundary line G2.

[0041] The body contour of the vehicle 1 is reproduced by a rectangle, the size of which is selected such that all areas of the vehicle 1, including, for example, the side mirrors of the vehicle 1, fit within this body contour.

[0042] In order to ensure that the vehicle 1 can be moved along the trajectory T without collisions, it is necessary to check that the path of the vehicle 1 resulting from the movement of the body contour along the trajectory T has no intersections with the boundary lines G1, G2. The path of the vehicle 1 can in particular be a tubular area which must be located within the boundary lines G1, G2 to ensure that there are no collisions on the trajectory T.

[0043] Checking for collisions on the trajectory T may be performed repeatedly based on discrete vehicle positions of the vehicle 1, as illustrated in FIG.

[0044] At a defined vehicle position, it must be checked whether the left vehicle contour is located to the right of the left border G1 and whether the right vehicle contour is located to the left of the right border G2. This test can be performed in the illustrated exemplary embodiment on the basis of the left front and left rear corners or the right front and right rear corners. It is necessary to check more precisely whether the left front and left rear corners have the same position relative to the left border G1, i.e. both are located to the right of the left border G1. The same applies for the right front and right rear corners relative to the right border G2. These two corners must also have the same position relative to the right border G2, i.e. both be located to the left of the right border G2.

[0045] As an example, this check involves determining the pair of points of the left boundary line G1 of the lane that are closest to the left vehicle contour. In the illustrated exemplary embodiment, these are points B and C. The left front corner of vehicle 1 is represented by point A. For a polyline consisting of the sequence of points BCA, this results in a clockwise rotation direction.

[0046] The same check is then made for the left rear corner of vehicle 1 relative to points B and C. If the polygonal polyline is traced from point B to C and back to point B via the left rear corner, this also results in a clockwise rotation direction. Thus, the check shows that both vertices of the left vehicle contour are on the same side of the left boundary line G1, i.e. the left vehicle contour does not cross the left boundary line G1 and therefore there is no collision with the left boundary line G1. Furthermore, it can be identified that both vertices of the left vehicle contour are on the right side of the left boundary line G1.

[0047] A similar check is performed for the two vertices of the right vehicle contour against the right boundary line G2.

[0048] As shown in Fig. 3, the right boundary line G2 is also represented by a number of points, with points B' and C' defining a line forming part of the right boundary line G2. In order to be able to identify whether the vehicle 1 has crossed this right boundary line G2 when travelling along the roadway, the above-mentioned algorithm is likewise carried out for the vertices of the right vehicle contour line: that is to say, a rotation direction is determined with respect to the right front corner A' of the vehicle contour line and the resulting polyline B'-C'-A', which rotation direction occurs when the polygonal polyline is followed in the above-mentioned direction of travel. In the illustrated exemplary embodiment, this is counterclockwise.

[0049] The same check is then performed for the right rear corner of the vehicle 1 for points B' and C'. If the polygonal polyline is traced from point B' to C' and back via the right rear corner of the vehicle 1 to point B', this also results in a clockwise rotation direction. Thus, the check shows that both vertices of the right vehicle contour are on the same side of the right boundary line G2, i.e. the right vehicle contour does not cross the right boundary line G2 and therefore there is no collision with the right boundary line G2. Furthermore, it can be identified that both vertices of the right vehicle contour are on the left side of the right boundary line G2.

[0050] The above mentioned checking steps are preferably repeated for multiple vehicle positions along the travel path and for different sections of boundary lines G1 and G2 (defined by the pair of points BC or B'-C') to ensure that there are no collisions on the trajectory T.

[0051] FIG. 4 shows an example in which the trajectory T has been determined such that the path of the vehicle 1 crosses the left boundary line G1 in the area marked by an oval, thus crossing the boundary of the drivable area.

[0052] A mismatch with the expected rotation direction is indicative of a particular boundary violation. FL , A RL , A FR , A RR The expected rotation direction for a polyline is:

[0053] [Table 1]

[0054] The section of boundary line G1 in the area of ​​vehicle 1 is point B L and point C L The left front corner of vehicle 1 is defined as point A. FL Point B L -C L -A FL For a polyline consisting of a sequence of points, this results in a counterclockwise rotation direction. L and point C L ) with respect to the left rear corner of vehicle 1 (point A RL ), this means that point B L -C L -A RL Tracing the polyline along,G1,results in a clockwise rotation direction.,Since the rotation directions are different for the,front and back corners, the proposed method makes it,possible to recognize crossings of the boundary line,G1,.

[0055] In order to recognize that the vehicle 1 is not completely outside the drivable area, it may be useful to check the position of a pair of left and right corners of the vehicle outline against at least one boundary line G1, G2 at each cycle or at a longer time interval. For example, point B L and point C L If a counterclockwise rotation direction occurs for the left corner of the vehicle contour of vehicle 1 relative to the line identified by and this rotation direction indicates that the left corner of the body contour is to the left of the left boundary line G1, it can be concluded from this that vehicle 1 is already located outside the drivable area at this point of the trajectory T and has therefore crossed the boundary of the drivable area. [Explanation of symbols]

[0056] 1 vehicle 2 Sensors 3. Computational Unit B. First point C. Second point A FL , A FL , A FR , A LR , A RR Third point Front body contour TD movement direction G1 Left border G2 right border T orbit

Claims

1. A computer-implemented method for monitoring whether a vehicle (1) moving along a track (T) crosses a boundary of a driveable area, comprising the steps of: a) receiving information regarding at least one boundary line (G1, G2) of the drivable area (S10); b) receiving information about the route along which the vehicle (1) is traveling (S11); c) selecting first and second points (B, C, B', C') on the at least one boundary line (G1, G2) of the drivable area, the first point (B, B') being behind the second point (C, C') in the direction of movement (TD) of the vehicle (1) (S12); d) at least one third point (A, A', A) located at the edge of the path of the vehicle (1); ＦＬ , A ＦＲ , A ＬＲ , A ＲＲ ) (S13), e) the first and second points (B, C, B', C', B Ｌ , C Ｌ ) with respect to the line between the at least third points (A, A', A ＦＬ , A ＦＲ , A ＬＲ , A ＲＲ ) to check the position of at least the third point (A, A', A ＦＬ , A ＦＲ , A ＬＲ , A ＲＲ a step (S14) of checking that a determination of the direction of rotation is made for each of the first and second rotations, in which it is checked whether the determined direction of rotation is a clockwise or counterclockwise direction; f) said at least third point (A, A′, A ＦＬ , A ＦＲ , A ＬＲ , A ＲＲ (S15) checking whether the vehicle (1) has crossed at least one of the boundaries (G1, G2) of the drivable area based on the checked rotation direction of the vehicle (1). The method includes:

2. 2. The method of claim 1, wherein said determining of said rotation direction is performed by determining a rotation direction for said third point (A,A') when following a polyline formed from said first point (B,B') through said second point (C,C') to said at least third point (A,A').

3. 3. A method according to claim 1 or 2, characterized in that at least one boundary line (G1, G2) of the drivable area is approximated by a plurality of points spaced apart from one another, and pairs of boundary line points are selected in turn as first and second points (B, C, B', C') and are used for verifying the direction of rotation and for the check as to whether the boundary of the drivable area is being crossed.

4. The at least third point (A, A′, A ＦＬ , A ＦＲ , A ＬＲ , A ＲＲ 4. The method according to claim 1, wherein the vertices of the vehicle (1) are vehicle vertices of a polygon reproducing the body contour of the vehicle (1).

5. 5. The method according to claim 1, wherein the drivable area has left and right boundary lines (G1, G2) spaced apart from one another and defining a driving lane, the vehicle body contour is approximated by a polygon having two left vehicle vertices and two right vehicle vertices, the positions of at least the two left corners relative to the line between the first and second points located on the left boundary line (G1) are checked at least intermittently, and for at least the two left vehicle vertices a rotation direction is determined in each case, i.e. by determining a rotation direction for each left vehicle vertex when following a polyline formed starting from the first point via the second point to the respective vehicle vertex, and checking whether the two rotation directions are clockwise.

6. 6. The method according to claim 1, wherein the drivable area has left and right boundary lines (G1, G2) spaced apart from one another and defining a driving lane, the vehicle body contour is approximated by a polygon having two left vehicle vertices and two right vehicle vertices, the positions of the two right vehicle vertices relative to the line between the first and second points located on the right boundary line (G2) are checked at least intermittently, and for the two right vehicle vertices a direction of rotation is determined in each case, i.e. by determining a direction of rotation for each right vehicle vertex when following a polyline formed starting from the first point via the second point to the respective vehicle vertex, and checking whether the two directions of rotation are counterclockwise.

7. 7. Method according to claim 1, characterized in that the determination of the direction of rotation and the monitoring of the direction of rotation are performed for all vehicle vertices which reproduce the body contour.

8. A driver assistance system designed to check whether a vehicle (1) has exceeded a boundary of a driving area, comprising a number of sensors (2) distributed around the vehicle (1) and a calculation unit (3) for processing information provided by said sensors (2), said calculation unit (3) comprising: a) receiving information regarding at least one boundary of the drivable area; b) receiving information about the path of the vehicle (1), the path being the zone covered by the projection of the vehicle body contour (F) onto the road when traveling along a track (T) (S11); c) selecting a first and a second point (B, C, B', C') on the at least one boundary line (G1, G2) of the drivable area, the first point (B, B') being behind the second point (C, C') in the direction of movement (TD) of the vehicle (1); d) a third point (A, A', A) located at the edge of the path of the vehicle (1); ＦＬ , A ＦＲ , A ＬＲ , A ＲＲ ), e) at least said third point (A, A', A') relative to a line between said first and second points (B, C, B', C'); ＦＬ , A ＦＲ , A ＬＲ , A ＲＲ ) to check the position of at least the third point (A, A', A ＦＬ , A ＦＲ , A ＬＲ , A ＲＲ ) a determination of the direction of rotation is made and whether the determined direction of rotation is a clockwise or counterclockwise direction; f) said at least third point (A, A′, A ＦＬ , A ＦＲ , A ＬＲ , A ＲＲ based on the verified rotation direction of the vehicle (1), determining whether the vehicle (1) has crossed at least one boundary line (G1, G2) of the drivable area. A driver assistance system configured to:

Images