Method for detecting an edge of a trailer vehicle in a vehicle combination for determining an articulation angle

Abstract

The invention relates to a method for detecting an edge of a trailer vehicle in a vehicle combination for determining an articulation angle, in particular for autonomously-driving vehicle combinations, in which method an edge (17) of the trailer vehicle (5) is determined by means of a camera (7, 9) by using known objects which are partially concealed by the trailer vehicle (5). In a method by means of which edge detection is simplified, the mirror camera (7, 9) oriented to the rear of the trailer vehicle (5) detects a part of the edge (17) of the trailer vehicle (5) and at least one lane marking (19), the position of which in the camera image is known through the use of a lane-accurate map, wherein the edge (17) of the trailer vehicle (5) is searched for in the camera image along the lane marking (19) and the complete edge length of the trailer vehicle (5) is extrapolated when the edge (17) is detected.

Description

[0001] Method for detecting an edge of a trailer of a vehicle combination to determine a bending angle

[0002] The invention relates to a method for detecting an edge of a trailer of a vehicle combination for determining a bending angle, in particular for autonomously driving vehicle combinations, in which an edge of the trailer is determined by means of a camera by using known objects that are partially hidden by the trailer.

[0003] US 2022 / 0396209 A1 discloses a camera monitoring system for determining a trailer angle. The trailer angle is estimated using a camera by placing a trailer marker or a trailing edge of the trailer in reference to a lane or road edge.

[0004] US 8,073,594 B2 discloses the application of a sensor fusion technique that processes information from more than one sensor to detect the edge of a trailer and, in further processing, to estimate the articulation angle of the trailer coupling.

[0005] A camera monitoring system is shown in US 2022 / 012 5045 A1 that identifies one end of a trailer while the trailer is visible in a specific image. The camera monitoring system includes an HMI system that extends a trailer end line horizontally from the end of the trailer. This trailer end line assists the vehicle driver in identifying objects, such as road features, in the field of view relative to the trailer.

[0006] WO 2019 / 202317 A1 describes a system for identifying the articulation angle of a trailer towed by a vehicle. The system comprises a camera mounted at a fixed orientation on the vehicle to capture an image of the trailer, and a processing unit arranged to receive image data from the camera. Feature points, such as edges, are identified in the image data relative to a stored map to estimate or calculate an articulation angle.

[0007] The object of the invention is to provide a method for detecting an edge of a trailer vehicle of a vehicle combination for determining a bending angle, with which the edge detection is simplified.

[0008] The invention is based on the features of the independent claims. Advantageous developments and refinements are the subject of the dependent claims. Further features, possible applications, and advantages of the invention will become apparent from the following description and the explanation of exemplary embodiments of the invention illustrated in the figures.

[0009] The problem is solved by the subject matter of patent claim 1.

[0010] In the method explained above for detecting an edge of a trailer of a vehicle combination to determine a kink angle, in particular for autonomously driving vehicle combinations, in which an edge of the trailer is determined by means of a camera using known objects that are partially obscured by the trailer, the mirror camera directed rearward to the trailer detects part of the edge of a long side of the trailer and at least one lane marking, the position of which in the camera image is known through the use of a lane-accurate map, wherein the edge of the trailer is searched for along the lane marking in the camera image and, upon detection of the edge, the complete edge length of the trailer is extrapolated. A mirror camera is understood to be a camera that replaces the rear-view mirror of the towing vehicle.Such cameras, known as mirror cameras, show the driver the image they have captured on a display unit in the cab. By using only the camera sensors in the towing vehicle and the lane-accurate map also present in the vehicle, process costs are reduced. The use of the mirror camera increases the contrast difference between the edge and the road markings, enabling clear detection. Advantageously, edge detection is adapted to the color of the lane markings. Since the colors of individual markings are known, for example, white for a normal lane or yellow for a lane in a construction zone, the computational effort required to determine the edge depending on the lane can be reduced.

[0011] Advantageously, the articulation angle between the towing vehicle and the trailer is determined based on the trailer's complete edge length and a known extrinsic position of the mirror camera. This allows the articulation angle to be determined using simple geometric formulas.

[0012] Further advantages, features, and details will become apparent from the following description, in which at least one exemplary embodiment is described in detail—possibly with reference to the drawing. Described and / or illustrated features may form the subject matter of the invention alone or in any meaningful combination, possibly independently of the claims, and may, in particular, also be the subject of one or more separate applications. Identical, similar, and / or functionally equivalent parts are provided with the same reference numerals.

[0013] They show:

[0014] Fig. 1 a schematic diagram of a commercial vehicle combination,

[0015] Fig. 2 shows an embodiment of a camera image to explain the method according to the invention.

[0016] Fig. 1 shows an embodiment of a commercial vehicle combination 1 designed as a semitrailer truck. The commercial vehicle combination 1 comprises a tractor unit 3 to which a trailer vehicle 5 in the form of a semitrailer is coupled. A mirror camera 7, 9, also referred to as a mirror cam, is attached to each of the two outer sides of the tractor unit 3. A mirror system comprising the mirror cameras 7, 9 each has a monitor 11, 13, which is coupled to the respective mirror camera 7, 9. In addition, the mirror cameras 7, 9 are connected to an evaluation unit 15 for detecting an edge 17 of the trailer vehicle 5. A lane-accurate map is stored in the evaluation unit 15. The mirror cameras 7, 9 capture a portion of the edge 17 of the semitrailer 5 with their field of view 23 in a camera image, which is shown in Fig. 2. Fig.Figure 2a shows the edge 17 of the trailer vehicle 5, recorded by the mirror camera 7, partially obscuring the lane marking 19. The evaluation unit 15 searches the image data for the lane marking 19 by extracting the lane information 21 from the lane-accurate map and superimposing the found lane information 21 over the visible lane marking 19 (Figure 2b), so that the exact course of the lane can be predicted. The evaluation unit 15 then extrapolates the total edge length of the trailer vehicle 5 from the determined data. The articulation angle is subsequently determined from the total edge length and a known extrinsic position of the mirror camera 7, 9.

[0017] List of reference symbols

[0018] 1 commercial vehicle combination

[0019] 3 tractor unit

[0020] 5 trailer vehicle

[0021] 7 mirror camera

[0022] 9 mirror camera

[0023] 11 monitors

[0024] 13 monitors

[0025] 15 Evaluation unit

[0026] 17 Edge of the trailer vehicle

[0027] 19 Lane markings

[0028] 21 Lane information from map

[0029] 23 Camera field of view

Claims

Patent claims 1. Method for detecting an edge of a trailer vehicle of a vehicle combination for determining a bend angle, in particular for autonomously driving vehicle combinations, in which method an edge (17) of the trailer vehicle (5) is determined by means of a camera (7, 9) by using known objects that are partially concealed by the trailer vehicle (5), characterized in that the mirror camera (7, 9) directed rearwardly to the trailer vehicle (5) detects part of the edge (17) of a long side of the trailer vehicle (5) and at least one lane marking (19), the position of which in the camera image is known through the use of a lane-accurate map, wherein the edge (17) of the trailer vehicle (5) is searched for in the camera image along the lane marking (19) and, upon detection of the edge (17), the complete edge length of the trailer vehicle (5) is extrapolated.

2. Method according to claim 1, characterized in that the edge detection is adapted to the color of the lane marking (19).

3. Method according to claim 1 or 2, characterized in that the articulation angle between the towing vehicle (3) and the trailer vehicle (5) is determined as a function of the complete edge length of the trailer vehicle (5) and a known extrinsic position of the mirror camera (7, 9).

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