Method for determining free space in a vehicle environment

Abstract

The invention relates to a method for determining at least one free space in a vehicle environment of a vehicle, wherein the method has the following steps: (a) receiving at least two-dimensional contour points (11) of an object (5) in the vehicle environment; (b) assigning the received contour points (11) to a plurality of rows (8) which divide at least one field of view (4) located in the vehicle environment and considered in the scope of the method in rows; (c) for at least a portion of the plurality of rows (8), respectively within a row (8), determining as a minimum contour point (13) such a contour point (11) which has the smallest contour point distance (15) to a reference system (2, 3) of the vehicle (1) of all contour points (11) assigned to the respective row (8) within the row (8); and (d) connecting the previously determined minimum contour points (13) as one free space (6) or a plurality of free spaces (6) within the at least one field of view (4) considered.

Description

Technical Field

[0001] The present invention relates to a method for determining at least one free space in the vehicle environment of a vehicle, a computer program product, a control device for a vehicle, a driver assistance system having the control device and vehicle sensors, and a vehicle. Background Technology

[0002] Different driver assistance systems in vehicles (such as electronic distance warning systems and automated parking systems) and various stages of autonomous driving (such as lane recognition) require data collection of the (static) vehicle environment. Ultrasonic sensors are typically used for driver assistance systems (such as automated parking systems or electronic distance warning systems). Other sensors used for more general identification of the static environment include camera sensors, laser scanners, or radar sensors.

[0003] The description of a static environment can be achieved using contour information. This contour information is related to the measurement principle and the signal processing used for identification and filtering. In radar sensors and laser scanners, the description of a static environment can be achieved using a list of points. The number of points is related to the measurement principle, signal processing, and observation time. Vehicle components that obtain such contour information can connect via, for example, CAN (Controller Area Network) or Ethernet. Such interfaces have limited bandwidth and may require a significant reduction in the amount of data transmitted. Another reason for the need for data reduction is the computational cost for the receiver, which may also be limited.

[0004] Due to the limited bandwidth, the amount of data required for subsequent processing steps in the vehicle's controls is limited. Most driver assistance functions do not require all the identified contours or collected contour information. The most frequently and often only required information is the free space or open space around the vehicle itself (also referred to as the vehicle's own space) in order to, for example, assess the probability of a collision or calculate a driving path.

[0005] Limited bandwidth leads to another desired requirement: the possibility of guaranteeing static resolution at every location within a defined field of view.

[0006] From the perspective of existing technology, there are different approaches to identify the static vehicle environment and extract free space information. Free space information can be defined as the space between the vehicle and the nearest (or more) static objects(s) in all directions within the field of view. In other words, this is the (drivable) space between the vehicle and all surrounding static objects in all relevant directions.

[0007] A typical scheme for identifying static contours is the evidence grid (Beweisgitter), as known from M. Schreier et al., “From Grid Maps to Parametric Free Space Maps – A Highly Compact, Generic Environment Representation for ADAS” (IEEE Intelligent Vehicle Symposium [IV 2013]). Each grid cell is marked as occupied or unoccupied according to a measurement that can be assigned to the cell during the last measurement cycle. There are different possibilities, i.e., determining, for example, based on a statistical function: a grid cell is occupied. In this case, the extraction of free space is straightforward: the free space consists of all unoccupied cells around the vehicle and between the vehicle and the nearest occupied grid cell. For this purpose, see also Hesham M. Eraqi, Jens Honer, and Sebastian Zuther, “Static free space detection with laser scanner using occupancy grid maps” (arXiv preprint arXiv:1801.00600

[2018] ) and Hundelshausen, F., & “Parking space detection with hierarchical dynamic occupancy grids” in Schmid, MR, Ates, S., Dickmann, J. (June 2011), Wuensche, H.-J. (2011 IEEE Intelligent VehiclesSymposium [IV], pp. 254-259).

[0008] This method is very common and offers the possibility of easy signal processing. However, the resolution of the extracted data is directly related to the size of the grid cells, and the computational cost (or runtime) for generating the grid cell information—which serves as the basis for free-space analysis—is very high.

[0009] Another method for free space estimation (assuming the contour already exists) is to calculate the intersection of lines, starting at the nearest contour element at this location [0, 0]. The line is rotated by a static or dynamic angle segment (at the static origin at this location), and for each step, the intersection with the nearest contour element is analyzed.

[0010] A very similar variation could be to use a rotating angle segment and check the area where the first identification is located.

[0011] This method is also very common, but the resolution of the free space boundary decreases as the range of action increases. Furthermore, this method relies on a direct line of sight. It cannot identify free space covered by contours, and it cannot observe around corners. This limits its applicability for automated driving, as it requires very low speeds to identify intersections. Summary of the Invention

[0012] The objective of this invention is to reduce the disadvantages known from the prior art. In particular, the objective of this invention is to provide a method for determining at least one free space in the vehicle environment of a vehicle, said method being particularly easy and reliable and significantly reducing the amount of data required compared to known methods.

[0013] The aforementioned task is solved by the technical solution according to the present invention, particularly by the method for determining at least one free space in the vehicle environment according to the present invention, the computer program product according to the present invention, the control device according to the present invention, the driver assistance system according to the present invention, and the vehicle according to the present invention. Here, the features and details disclosed in connection with the method according to the present invention also apply to the features and details disclosed in connection with the computer program product according to the present invention, the control device according to the present invention, the driver assistance system according to the present invention, and the vehicle according to the present invention, and vice versa, so that the disclosures regarding various aspects of the invention are always mutually related or can be mutually related.

[0014] According to a first aspect, the present invention solves the task by a method for determining at least one free space in the vehicle environment of a vehicle, wherein the method comprises the following steps:

[0015] (a) Receive at least two-dimensional contour points of an object in the vehicle environment;

[0016] (b) Assigning the received contour points to multiple rows, the rows dividing at least one field of view located in the vehicle environment and considered within the scope of the method;

[0017] (c) For at least a portion of the plurality of rows, within each row, a contour point is selected as the minimum contour point, which, within the corresponding row, has the smallest contour point distance to the vehicle's reference frame among all contour points assigned to that row; and

[0018] (d) Connect the previously determined minimum contour points into one or more free spaces within the at least one field of view under consideration.

[0019] Accordingly, the present invention provides a method for reducing data throughout the signal processing chain within a vehicle's control unit or driver assistance system (and a computer program product according to a second aspect of the invention). This consistently reduces computational costs and storage space requirements. Furthermore, in a sense, at least one or more free spaces can be determined particularly easily from the reduced amount of data. Another important advantage of implementation according to the invention is the fixed (positional) resolution of the free space description.

[0020] The method can, in principle, be performed in a two-dimensional plane, wherein two-dimensional contour points of an object in the vehicle environment are received according to method step (a), and these contour points are processed according to method steps (b) to (d). However, it is self-evident that the method may also be performed in multiple two-dimensional planes or in three-dimensional space. Here, three-dimensional contour points of an object in the vehicle environment can be received in method step (a). The three-dimensional contour points of the object in the vehicle environment can then be processed according to method steps (b) to (d), wherein this can be implemented separately for each of the multiple two-dimensional planes or generally for the entire three-dimensional space. As will be explained later according to different driver assistance systems or application areas of the method, it may be meaningful to consider different two-dimensional planes or planes at different heights for different driver assistance systems or application areas, and thus (acquire and) receive at least two-dimensional contour points for different planes or heights.

[0021] Accordingly, free space can be defined as two-dimensional or three-dimensional free space. The free space can be defined or determined by the vehicle or the smallest contour point connected to the vehicle. The vehicle is understood to be a vehicle in which or by which the method is performed or the driver assistance system is used. Free space can then be defined as the space between the vehicle and the nearest (or more) static objects(s) within the vehicle environment (for all directions) in the considered field of view. In other words, free space can be represented as the (drivable) space between the vehicle and all surrounding static objects in the considered field of view.

[0022] The field of view (FOV) under consideration can be predetermined regarding its position in the vehicle environment, its orientation, and / or its size, or it can be individually selected based on the specific application of the driver assistance system or the method. Thus, the FOV can differ for different application areas of the method, allowing for the consideration of different FOVs within the scope of the method implemented for different application areas. Here, the FOV can be defined as a two-dimensional or three-dimensional field of view. Dividing the FOV into multiple rows can be predetermined or similarly defined based on the application area. This allows for different resolutions of the FOV, where more or fewer rows are selected for the division. With a smaller number of rows or, given a given number of rows, a correspondingly larger row height for each row, the resolution decreases, thereby further reducing the amount of data. Here, the resolution can be chosen such that it is (just) sufficient for the application area or the corresponding driver assistance system. In principle, the number of FOVs under consideration is not limited. The FOV can be arranged not only at right angles but also rotated relative to the vehicle.

[0023] It can be specified that the at least one field of view is rectangular or (partially) circular. Thus, the shape or geometry of the field of view can be predefined, or it can be specifically selected for the corresponding application area of ​​the method or the corresponding driver assistance system of the vehicle. In the case of a circular geometry of the field of view, each field of view is circular. In the case of a partially circular geometry of the field of view, multiple considered fields of view can together surround or cover a circular vehicle environment. In particular, this can relate to a ring-shaped vehicle environment, which can be monitored in such a way that the vehicle is located within the ring, and the monitored ring of the vehicle environment is formed by the respective fields of view.

[0024] Minimum contour points are determined within at least a portion of the rows, or within each row of all the rows in the field of view, where the contour points have the minimum contour point distance from the vehicle's reference frame within the rows they have been assigned to. In other words, such minimum contour points are determined for each contour point within a row, where the minimum contour point has the minimum distance to the reference frame or contour point distance. This is performed or repeated for at least a portion of the rows, or for all the rows in the multiple rows. Thus, minimum contour points within a portion of the multiple rows are obtained. The remaining received contour points can be disregarded, in particular (from the memory where these contour points are stored), to reduce the amount of data. Minimum contour points are determined only for a portion of the multiple rows based on the minimum contour point distance, which can then be, for example, a situation where no contour points are assigned to individual rows. This can then occur, in particular, when the resolution of the field of view under consideration has been selected to be very high or when the field of view is divided into a large number of rows.

[0025] Connecting the previously determined minimum contour points into one or more free spaces within the at least one field of view under consideration can be determined by connecting the nearest minimum contour points of the corresponding rows, i.e., by using inclined connecting lines between the minimum contour points, or (if this should be very memory-efficient and computation-time-efficient) by simply connecting the row spacing (thus producing a stepped pattern (see...) Figure 6 )).

[0026] Specifically, the method can be a computer-implemented method. As such a method, the method can be executed by one or more computers. "Computer" is also understood as a control device, particularly a vehicle control device, or as a control device including a computer. A computer can also be referred to as a processing unit.

[0027] Regardless of how the method steps are numbered to distinguish them from each other, it is not mandatory that the method steps be performed in the proposed order. It may still be specified that the method steps are performed in the proposed order (a) to (d).

[0028] Furthermore, it can be specified that the reference frame is formed by at least one or more reference points. Specifically, it can be specified that the reference frame is the vehicle's longitudinal axis and / or transverse axis. Here, a profile point can be determined as the minimum profile point, which has the minimum profile point distance to one of the two axes (i.e., the vehicle's longitudinal axis or transverse axis). Here, the profile point distance is not determined, for example, as the distance to a previously determined reference point on the corresponding axis. Instead, the reference point for the profile point distance is different for each profile point, so as to obtain a profile point distance normalized according to the interval from or toward the corresponding axis. This allows for easy and accurate determination of the minimum profile point.

[0029] Furthermore, the method may include a step of acquiring contour points of objects in the vehicle environment using vehicle sensors. This can be achieved using a driver assistance system or one or more vehicle sensors. For example, ultrasonic sensors, camera sensors, laser scanners, and / or radar sensors may be used as vehicle sensors. Thus, contour points can be acquired with high precision so that they can be subsequently transmitted fully or selectively and ultimately received according to step (a) of the method.

[0030] Furthermore, it can be specified that at least two fields of view located within the vehicle environment are considered in the method, and method steps (c) and (d) are performed for at least two of the at least two fields of view. A larger vehicle environment can be considered by considering two different fields of view. For example, considering two mutually parallel fields of view located to the sides of the vehicle can be used to implement lane recognition, which could be an application area of ​​the method or a corresponding driver assistance system.

[0031] Alternatively, the method may be specified to consider four fields of view within the vehicle environment, which together depict the vehicle environment completely surrounding the vehicle; and method steps (c) and (d) may be performed for at least two or all of the four fields of view. In this regard, the entire vehicle environment can, of course, be monitored. Depending on the application domain of the method or the vehicle's driver assistance system, only the required fields of view may be analyzed and processed according to method steps (c) and (d) to determine the free space necessary for the application domain or driver assistance system, respectively.

[0032] It can also be specified that, for different applications in the driver assistance system, at least one application field of view from at least two fields of view is determined, wherein the application field of view is relevant to the application, and method steps (c) and (d) are performed in the method considering the at least one application field of view and for the at least one application field of view from the at least two fields of view. In other words, one or two or more fields of view can be selected to be considered depending on the application domain of the method or the driver assistance system, as previously described. If only such (application) fields of view are considered from multiple possible fields of view, and these fields of view are required for the current application domain of the method or the corresponding driver assistance system of the vehicle, then the amount of data can be reduced to some extent. For example, if the application domain of the method is a vehicle or the vehicle's automated side parking, or if the driver assistance system is an automated side parking system, then it is generally sufficient to consider the application field of view located behind the vehicle, the application field of view located in front of the vehicle, and the application field of view located to the side of the vehicle. Non-essential contour points within the possible (non-application) field of view in front of the vehicle and another (non-application) field of view to the side of the vehicle are not necessary, or at least not mandatory, to be acquired or processed for the application area or driver assistance system, so that safe, automated side parking can be implemented in the defined free space without physical contact between the vehicle and the object. Thus, because no free space is defined in parts of the field of view or vehicle environment that is not important to the application area or driver assistance system, the amount of data is reduced.

[0033] Specifically, it can be specified that an available parking space is determined based on the at least one free space. To this end, a comparison can be made between the determined at least one free space and the size (and geometry) of the available parking space required for parking. If the determined at least one free space contains an available parking space, or if the size (and geometry) of the available parking space is suitable for parking, then an available parking space can be determined. Accordingly, the determined available parking space can be used in the application of the method for automated parking or in a driver assistance system to allow the vehicle to be parked safely within it.

[0034] Finding available parking spaces is only one possible application of the method according to the invention. The determined free space can also be used in other applications or driver assistance systems (such as autonomous driving (at various levels), curbstone recognition), and for other purposes described within the scope of this specification.

[0035] Furthermore, it can be stipulated that for rows without assigned contour points, the contour points of the nearest adjacent rows are determined, and these contour points are interconnected by connecting lines. The point on the connecting line with the smallest contour point distance within the rows without assigned contour points is then identified as the minimum contour point. This point on the connecting line typically lies on one of the two line lines of the corresponding row, which separates the row from its adjacent rows. The point can also be considered as the intersection of the line and one of the line lines. Therefore, it is possible to approximately determine the minimum contour point in rows without assigned contour points. As previously mentioned, this can be advantageous when the resolution is very low.

[0036] Furthermore, it can be stipulated that, in the case where the line connecting the contour points of a row to the contour points of adjacent rows has a point within that row that has a smaller contour point distance than the contour point assigned to that row, then the point with the smaller contour point distance on the connecting line is taken as the minimum contour point. This is particularly feasible in cases of low resolution and / or a small number of contour points within a row: due to the incorrect determination of the minimum contour point, the free space to be determined is reduced to facilitate accurate identification. In other words, the connecting line is used as a comparison parameter for whether the contour points within each row actually represent the minimum contour point, or whether the intersection of the connecting line with one of the two row lines of these rows actually indicates a more likely, or at least more reliable, minimum contour point in terms of accurate identification.

[0037] Furthermore, it can be specified that the line height of the plurality of lines of the considered field of view and / or the position of the at least one field of view within the vehicle environment are determined based on at least one driving parameter (particularly speed). Here, the number of lines can, of course, also be varied. This allows the method to be improved by adapting the field of view to at least one driving parameter (such as speed). Thus, the amount of data can be reduced or increased according to the requirements indicated by the at least one driving parameter. It is also implied that the size of the field of view can be determined overall, i.e., for example, by means of the selection of line width and / or the number of lines, based on the at least one driving parameter.

[0038] Furthermore, it can be specified that different rows among multiple rows in the considered field of view are determined to have different row heights. This allows for localized resolution improvement in critical regions of the considered field of view, while resolution can be reduced in non-critical regions to decrease data volume.

[0039] According to a second aspect of the invention, the task mentioned at the beginning is solved by a computer program product comprising instructions that, when executed by a computer, cause the computer to perform the method according to the first aspect of the invention.

[0040] Here, "computer" is specifically understood as a vehicle control device, or at least as such a control device including a computer, which may also be called a computing unit.

[0041] According to a third aspect of the invention, the task mentioned at the beginning is solved by a control device for a vehicle, wherein the control device is configured to implement the method according to the first aspect of the invention.

[0042] The control device may include a computer or a computing unit. Furthermore, the control device may include a storage medium. A computer program product according to the second aspect of the invention may be stored on the storage medium. The computer of the control device can ultimately execute the instructions included in the computer program product to perform the method according to the first aspect of the invention.

[0043] According to a fourth aspect of the invention, the task mentioned at the beginning is solved by a driver assistance system having a control device according to a third aspect of the invention and a vehicle sensor for acquiring contour points of objects in the vehicle environment.

[0044] Vehicle sensors can be configured to transmit acquired contour points to a control device, which then receives the contour points. Specifically, a driver assistance system may have multiple vehicle sensors for acquiring contour points of objects in the vehicle environment. These vehicle sensors may be of the same or different types. For example, vehicle sensors may be ultrasonic sensors, camera sensors, laser scanners, and / or radar sensors.

[0045] According to a fifth aspect of the invention, the task mentioned at the beginning is solved by a vehicle having a driver assistance system according to a fourth aspect of the invention.

[0046] It goes without saying that driver assistance systems can provide different application areas or assistance functions (such as automated parking or electronic distance recognition), or a vehicle may include multiple driver assistance systems for different application areas. In the case of different driver assistance systems, these driver assistance systems may have common control devices or different control devices, which are provided according to the third aspect of the invention. Furthermore, it may be specified that each driver assistance system can access the same vehicle sensors or include such vehicle sensors.

[0047] Other improvements to the invention arise from the subsequent description of the various embodiments of the invention schematically illustrated in the accompanying drawings. All features and / or advantages (including construction details and spatial arrangements) known from the specification or drawings may be essential to the invention not only individually but also in different combinations. Attached Figure Description

[0048] The invention is illustrated in more detail below with reference to the accompanying drawings. In the drawings:

[0049] Figure 1 A schematic top view showing a first graphical representation relating to a method according to the invention according to one embodiment;

[0050] Figure 2 A schematic top view showing a second graphical representation in relation to an exemplary field of application of the method according to the invention;

[0051] Figure 3 A schematic top view showing a third graphical representation in relation to the method according to the invention;

[0052] Figure 4 A schematic top view showing a fourth graphical representation relating to another exemplary field of application of the method according to the invention;

[0053] Figure 5 Show Figures 1 to 4 A schematic diagram showing the division of the field of view into rows;

[0054] Figure 6 A schematic graphical representation of each method step in the method according to the invention is shown;

[0055] Figure 7 A side view of a vehicle according to the invention is shown according to one embodiment;

[0056] Figure 8 A schematic diagram illustrating the steps of the method according to the present invention; and

[0057] Figure 9 Shown in Figure 7 A schematic diagram of a control device in a vehicle according to the present invention. Detailed Implementation

[0058] exist Figures 1 to 9 In this drawing, elements with the same function and mode of operation are given the same reference numerals. If the same element is shown or present more than once in one of the figures, the elements are numbered consecutively only for better distinction and for clear reference. The consecutive numbering follows the reference numeral and is separated from it by a dot.

[0059] Figure 1 This illustrates an embodiment of the invention and method 30 according to the invention (see reference). Figure 8 The first graphic representation of the vehicle 1 is shown. The vehicle 1 has reference frames 2 and 3. Here, the reference frames are formed by the vehicle's longitudinal axis 2 and by the vehicle's transverse axis 3.

[0060] Within the vehicle environment of vehicle 1, a field of view 4 is considered within the scope of method 30. For said field of view 4, only the vehicle's longitudinal axis 2 is used as a reference frame in the following text. By means of method 30, the free space 6 within the considered field of view 4 (see...) Figure 2 , 4 The defined free space 6 can be used for different application areas of vehicle 1 or for different driver assistance systems 20 (see 6). Figure 7 ), or for driver assistance systems 20 used in different application areas of vehicle 1.

[0061] For example, in Figure 2 The diagram shows a second graphical representation relating to method 30 according to the invention, wherein a free space 6 for parking vehicle 1 is located within the considered field of view 4, in which vehicle 1 can be parked. In other words, it relates to the application area of ​​side parking of vehicle 1. For example, the application area may relate to driver assistance system 20 or electronic distance warning system for automated parking. Here, the free space 6 to be determined is located between two objects 5.1 and 5.2, which in this case are other vehicles.

[0062] In addition to following Figure 1 , 2 In addition to considering only one field of view 4, as shown in the third graphical representation: more than one field of view 4 can also be considered within the scope of the method 30 according to the invention, in which one or more free spaces 6 should be detected. Figure 3 Four fields of view 4.1, 4.2, 4.3, and 4.4 are shown here as an example.

[0063] exist Figure 4 In the graphical representation, an exemplary application area with a driver assistance system 20 in the form of an automated parking system or an electronic distance warning system is shown again. However, here, four fields of view 4.1, 4.2, 4.3, and 4.4 are identified, which completely cover the vehicle environment of vehicle 1 or completely or 360° surround vehicle 1. Within fields of view 4.1, 4.2, 4.3, and 4.4, there are also objects 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, and 5.7, and between these objects are free spaces 6.1 and 6.2, which are large enough to be used as parking spaces, and which can be determined within the scope of method 30. Fields of view 4.1, 4.2, 4.3, and 4.4 are exemplary selected here as rectangles and overlapping each other. Alternatively, fields of view 4.1, 4.2, 4.3, and 4.4 may not overlap or may have another shape or geometry, such as a circle.

[0064] Figure 5This describes how the field of view 4 is divided into multiple rows 8.1-8.N within the scope of method 30 so that the field of view can be analyzed and processed by means of method 30, as explained in more detail below. Here, each row in rows 8.1-8.N has a row height 9a and a row width 9b. In this way, the multiple rows 8.1-8.N define the size of the field of view 4.

[0065] Figure 6 Now, a graphical representation of a portion of method 30 according to the invention is shown, as in Figure 8 The diagram shows and about Figure 6 and 8 To explain that in more detail.

[0066] Here, Figure 7 The vehicle 1 is schematically shown, having components used for this purpose, namely a driver assistance system 20, which has a control device 21 for performing the method 30 and at least one vehicle sensor 22. Figure 7 The representation here is merely illustrative, thus the vehicle sensor 22 can of course be located at any position and can also be formed by multiple vehicle sensors 22.

[0067] In the first method step 31 (see Figure 8 In the process, vehicle sensor 22 first acquires contour points 11.1-11.12, which describe the contour of object 5 in the vehicle environment (external). Figure 2 and 4 As shown in the diagram. Figure 6 These contour points are graphically depicted. For simplicity, in this example, only the field of view 4, set parallel to the vehicle's longitudinal axis 2, is considered as field of view 4. The position and size of this field of view 4 have already been determined specifically for the application area (e.g., side parking). Besides the application areas already exemplarily illustrated, this could, for example, involve curbstone detection. Here, field of view 4 can be set at a height within the range of the curbstone edge. Contour points 11.1-11.12 can be at least two-dimensional, i.e., determined by two coordinates in space (here, the graphic plane). It is also still possible to acquire three-dimensional contour points 11.1-11.12 at different heights or over the entire height range. This can be specifically selected for the application area.

[0068] In the second method step 32, the contour points 11.1-11.12 of the object 5 in the vehicle environment, acquired by means of the vehicle sensor 22, are transmitted to the control device 21 and received thereon. These contour points can be stored in the storage unit 41 of the control device 21 (see [link to relevant documentation]). Figure 9 ).

[0069] In step 33 of the third method, the received contour points 11.1-11.12 are assigned to a limited number of rows 8.1-8.8, which divide the field of view 4 within the vehicle environment and considered in the scope of the method by rows. For example, contour points 11.2 and 11.3 are assigned to row 8.1. Contour point 11.4 is assigned to row 8.2. Contour point 11.5 is assigned to row 8.3. Contour points 11.6, 11.7, and 11.8 are assigned to rows 8.4, 8.6, and 8.7, respectively. Contour point 11.9 is assigned to both rows 8.7 and 8.8. Here, none of the contour points 11.1-11.12 are assigned to row 8.5 because none of them are located within row 8.5. In other words, the allocation is a local configuration of contour points 11.1-11.12 to rows 8.1-8.8 of field of view 4. Contour points 11.1, 11.10, 11.11, and 11.12 are located outside field of view 4 and therefore are not assigned to any row 8.1-8.8. These received contour points 11.1, 11.10, 11.11, and 11.12 located outside field of view 4 can be deleted from the storage unit 41 in the control device 21 to reduce the amount of data to be processed and thereby reduce the computational cost of the computer-implemented method 30.

[0070] In step 34 of the fourth method, for each row 8.1-8.8, the remaining or assigned contour points 11.2-11.9 of rows 8.1-8.8 are determined such that these contour points have a minimum contour point distance 15 to reference frames 2 and 3 within the corresponding rows 8.1-8.8 (the measurement of this distance is exemplarily shown here). Reference frames 2 and 3 are given here by the vehicle longitudinal axis 2, since the field of view 4 is parallel to it. The contour points 11.2-11.9 having a minimum contour point distance 15 to the vehicle longitudinal axis 2 are hereinafter referred to as minimum contour points 13.1-13.3 (first type).

[0071] For example, the process in step 34 of the fourth method should be explained at line 8.1. Two contour points 11.2 and 11.3 have been assigned to line 8.1. Here, contour point 11.3 is closer to the vehicle's longitudinal axis 2 than contour point 11.2. In other words, contour point 11.3 has a smaller contour point distance 15 than contour point 11.2. Accordingly, contour point 11.3 is determined as the minimum contour point 13.1. The same process is now repeated for the remaining lines 8.2-8.8. Here, minimum contour points 13.2 and 13.3 are determined.

[0072] However, unlike the process described above, the unique contour point 11.4 assigned to row 8.2 is not now determined as the minimum contour point 13. The fourth method step 34 can be supplemented by a check that searches for a better solution for acquiring the contour of object 5 in field of view 4 within row 8.2, or at least checks whether contour point 11.4 should actually be assumed to be the minimum contour point 13 or whether this constitutes the best solution. This check examines whether the line connecting contour point 11.4 of row 8.2 to one of the contour points 11.2, 11.3, and 11.5 of adjacent rows 8.1 and 8.3 (specifically, assuming the minimum contour point 13 is predetermined) has a point within row 8.2 that has a smaller contour point distance 15 than the contour point 8.2 assigned to row 8.2. If this is the case, then the point on the connecting line with the smaller contour point distance 15 is chosen as the minimum contour point 14. The minimum contour point 14 can also be referred to as the second type, in order to distinguish it from the minimum contour point 13 obtained according to the direct determination of the minimum contour point distance 15 as previously explained, which can also be referred to as the first type.

[0073] For example, for line 8.2, the process should be described in more detail according to this optional determination of the second type of minimum profile point 14.1 instead of the first type of minimum profile point 13. Line 8.2 contains a unique profile point 11.4. The line connecting to the minimum profile point 13.1 of line 8.1 now intersects the downline of line 8.2, which has a smaller profile point distance 15 to the vehicle longitudinal axis 2. However, the line connecting profile point 11.4 to the profile point 11.5 of the adjacent line 8.3 produces a smaller profile point distance 15 at its intersection with the upline of line 8.2. This point is now determined as the second type of minimum profile point 14.1 of line 8.2.

[0074] The same optional process for determining the minimum contour points 14.2 and 14.4 of the second type is also implemented in rows 8.3 and 8.7. However, a special feature arises in row 8.5, which is not assigned contour point 11. Here it can be specified that the connecting line of contour points 11.6 and 11.7 of adjacent rows 8.4 and 8.6 is considered. The intersection with row 8.5 here also produces the possible minimum contour point 14 of the second type. Here, the intersection with the downline of row 8.5 is the minimum contour point 14.3 with the minimum contour point distance 15, and therefore said intersection is used to form the contour line 12 of one or more objects 5 in the field of view 4.

[0075] All other contour points 11.2, 11.4, 11.7, 11.9 (that is, contour points that are not the minimum contour point 13) can now be deleted from storage unit 41 in order to reduce the amount of data used for further method 30.

[0076] In step 35, the smallest contour points 13 and 14 (i.e., the first and second types) are now connected to form the contour line 12 of object 5, as previously explained. Simultaneously, this contour line 12 forms the free space boundary of free space 6 within the field of view 4. In other words, free space 6 is obtained as the free area within the field of view 4 from vehicle 1 to the contour line 12 of object 5. The free space 6 obtained in this way can now be used in driver assistance systems 20 or in applications such as, for example, automated parking, because vehicle 1 thus possesses information such as how far it can move laterally without colliding with object 5 located in the field of view 4.

[0077] Figure 9 The details of a control device 21 having a computer 42 or a processing unit and a storage unit 41 are shown purely schematically. A computer program product 40 is stored in the storage unit 41, and the control device, when executed by the computer 41, causes the computer to perform operations according to... Figure 8 Method 30.

[0078] List of reference numerals

[0079] 1 vehicle

[0080] 2. Vehicle longitudinal axis

[0081] 3 vehicle transverse axis

[0082] 4 fields of view

[0083] 5 objects

[0084] 6 Free Space

[0085] 8 lines

[0086] 9a line height

[0087] 9b line width

[0088] 10. Object outline

[0089] 11 contour points

[0090] 12 outlines

[0091] 13 Minimum Contour Points (Type I)

[0092] 14 Minimum Contour Points (Type II)

[0093] 15 contour point distance

[0094] 20 Driver Assistance Systems

[0095] 21 Control Device

[0096] 22 vehicle sensors

[0097] 30 methods

[0098] 31 First Method Steps

[0099] 32. Second method steps

[0100] 33 Third Method Steps

[0101] 34. Fourth Method Steps

[0102] 35. Fifth Method Steps

[0103] 40 Computer Program Products

[0104] 41 storage units

[0105] 42. Computers.

Claims

1. A method for determining at least one free space in the vehicle environment of a vehicle, wherein, The method comprises the following steps: (a) Receive at least two-dimensional contour points (11) of an object (5) located in at least one field of view in the vehicle environment. (b) Assigning the received contour points (11) to a plurality of rows (8) that divide the at least one field of view, wherein different rows (8) of the plurality of rows (8) of the field of view under consideration are determined to have different row heights (9a), and / or wherein the row heights (9a) of the plurality of rows (8) of the field of view under consideration are determined according to at least one driving parameter and / or the position of the at least one field of view under consideration within the vehicle environment; (c) For at least a portion of the plurality of rows (8), within each row (8), a contour point (11) is determined as a minimum contour point (13) of the first type, wherein the minimum contour point of the first type has the smallest contour point distance (15) to the reference frame of the vehicle (1) among all contour points (11) assigned to that row (8); and (d) Connect the previously determined minimum contour points (13) of the first type within the at least one field of view under consideration to form a contour line (12) that extends across the plurality of rows (8) and forms the free space boundary of the at least one free space (6). Before connecting the minimum contour point (13) of the first type, all contour points (11) that were not found to be the minimum contour point (13) of the first type are deleted. In this process, for each row (8) without an assigned contour point (11), the nearest adjacent contour point (11) of each row (8) is determined, and the contour points are connected to each other by means of a connecting line, so that the point with the smallest contour point distance (15) in each row (8) without an assigned contour point (11) on the connecting line is selected as the minimum contour point (14) of the second type.

2. The method according to claim 1, wherein, The reference frame is the vehicle's longitudinal axis (2) and / or vehicle transverse axis (3).

3. The method according to claim 1 or 2, wherein, The method also includes the step of acquiring the contour points (11) of an object (5) in the vehicle environment by means of the vehicle sensor (22) of the vehicle (1).

4. The method according to claim 1 or 2, wherein, The method considers at least two fields of view located in the vehicle environment, and performs method steps (c) and (d) for at least two of the at least two fields of view.

5. The method according to claim 4, wherein, In the method, four fields of view located in the vehicle environment are considered, which together depict the vehicle environment that completely surrounds the vehicle (1); and method steps (c) and (d) are performed for at least two of the four fields of view.

6. The method according to claim 1 or 2, wherein, For different applications in the driver assistance system (20), at least one application field of view of at least two fields of view is determined, the application field of view being relevant to the application, and the method steps (c) and (d) are performed in the method considering the at least one application field of view and for the at least one application field of view of the at least two fields of view.

7. The method according to claim 1 or 2, wherein, Available parking spaces are determined based on at least one free space (6).

8. The method according to claim 1 or 2, wherein, In the following case: that is, in the case where the line connecting the contour point (11) assigned to a row (8) to the contour point (11) of each adjacent row (8) has a point in the row (8) that has a smaller contour point distance (15) than the contour point (11) assigned to the row (8), then the point with a smaller contour point distance (15) on the line is selected as the minimum contour point (14) of the second type.

9. The method according to claim 1 or 2, wherein, The at least one driving parameter is speed.

10. A computer program product comprising instructions that, when executed by a computer (42) of the computer program product (40), cause the computer to perform the method according to any one of claims 1 to 9.

11. A control device for a vehicle, wherein, The control device (21) is configured to implement the method according to any one of claims 1 to 9.

12. A driver assistance system comprising: a control device (21) according to claim 11; and a vehicle sensor (22) for acquiring contour points (11) of an object (5) in the vehicle environment.

13. A vehicle having a driver assistance system (20) according to claim 12.

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