# US 12,216,197 B2 · Method and system for determining an articulation angle of a vehicle combination > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,216,197 B2 - Document ID: US12216197B2 - Status: Granted - Kind: B2 - Application number: 18/081,834 - Filed: 2022-12-15 - Published: 2023-06-22 - Granted: 2025-02-04 - Earliest claimed: 2021-12-21 - Assignees: Volvo Truck Corporation - Applicants: Volvo Truck Corporation - Inventors: Daniel Persson; Hans Deragården - Web page: https://patentgrep.com/patent/US12216197B2 ## CPC - G01S 13/89: for mapping or imaging - G06T 7/70: Determining position or orientation of objects or cameras (camera calibration G06T7/80) - G06T 7/60: Analysis of geometric attributes - G06V 10/44: Local feature extraction by analysis of parts of the pattern, e.g. by detecting edges, contours, loops, corners, strokes or intersections; Connectivity analysis, e.g. of connected components - G06V 20/58: Recognition of moving objects or obstacles, e.g. vehicles or pedestrians; Recognition of traffic objects, e.g. traffic signs, traffic lights or roads - G06T 2207/10021: Stereoscopic video; Stereoscopic image sequence - G06T 2207/10028: Range image; Depth image; 3D point clouds - G06T 2207/30252: Vehicle exterior; Vicinity of vehicle - G01S: RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES - G06T: IMAGE DATA PROCESSING OR GENERATION, IN GENERAL - G06V: IMAGE OR VIDEO RECOGNITION OR UNDERSTANDING ## Abstract A method for determining an articulation angle of a vehicle combination comprising a first vehicle section, such as a truck, and a second vehicle section, such as a trailer or dolly unit, which are connected via a first articulation joint, wherein the first vehicle section comprises an image obtaining device which is configured to obtain images of the second vehicle section during use, the method comprising obtaining a first image of the second vehicle section by the image obtaining device; mirroring the first image, thereby obtaining a second mirrored image; determining the articulation angle between the first and the second vehicle sections based on a required level of relative rotation of the first image and the second mirrored image until the first image and the second mirrored image match each other. ## Claims ### Claim 1 A method for determining an articulation angle of a vehicle combination comprising a first vehicle section, such as a truck, and a second vehicle section, such as a trailer or dolly unit, which are connected via a first articulation joint, wherein the first vehicle section comprises an image obtaining device which is configured to obtain images of the second vehicle section during use, the method comprising: obtaining a first image of the second vehicle section by the image obtaining device; mirroring the first image, thereby obtaining a second mirrored image; and determining the articulation angle between the first and the second vehicle sections based on a required level of relative rotation of the first image and the second mirrored image until the first image and the second mirrored image match each other. ### Claim 2 (depends on 1) The method of claim 1, wherein the first image is a range image with each pixel of the first image being associated with a distance with respect to the image obtaining device. ### Claim 3 (depends on 1) The method of claim 1, wherein the relative rotation corresponds to a rotation about a height axis of the vehicle combination which intersects the first articulation joint, wherein the height axis of the first vehicle combination extends in a height direction of the vehicle combination. ### Claim 4 (depends on 1) The method of claim 1, wherein the first image is mirrored with respect to a plane defined by the height axis and a mid-longitudinal axis of the first vehicle section, wherein the mid-longitudinal axis intersects the first articulation joint. ### Claim 5 (depends on 1) The method of claim 1, wherein the articulation angle is determined based on an assumption that a height axis and a mid-longitudinal axis of the second vehicle section which intersects the articulation joint defines a symmetry plane for the second vehicle section, wherein the height axis of the second vehicle section extends in a height direction of the second vehicle section. ### Claim 6 (depends on 1) The method of claim 1, wherein determining the articulation angle between the first and the second vehicle sections comprises identifying at least one tracking portion on the second vehicle section in the first image and identifying the at least one tracking portion on the second vehicle section in the second mirrored image, wherein the first image and the second mirrored image are considered to be matched when the at least one tracking portion in the first image coincides with the at least one tracking portion in the second mirrored image. ### Claim 7 (depends on 5) The method of claim 5, wherein determining the articulation angle between the first and the second vehicle sections comprises identifying a first and a second tracking portion of the second vehicle section in the first image and identifying the first and the second tracking portions of the second vehicle section in the second mirrored image, wherein the first and the second tracking portions are provided on respective sides of the symmetry plane, and wherein the first image and the second mirrored image are considered to be matched when the respective first and second tracking portions in the first image coincide with the respective first and second tracking portions in the second mirrored image. ### Claim 8 (depends on 6) The method of claim 6, wherein the at least one tracking portion is any one of a trailer support leg or a pair of trailer support legs, a chassis portion, such as longitudinally and/or transversely extending support bars, one or more drive-under-trailer-protection-frames and ground engaging means, such as wheels. ### Claim 9 (depends on 1) The method of claim 1, wherein the determined articulation angle corresponds to half the required level of relative rotation. ### Claim 10 A system for determining an articulation angle of a vehicle combination comprising a first vehicle section, such as a truck, and a second vehicle section, such as a trailer or dolly unit, which are connected via a first articulation joint, wherein the system comprises an image obtaining device which is provided on the first vehicle section and configured to obtain images of the second vehicle section during use, wherein the system comprises a processing unit which is configured to: obtain a first image of the second vehicle section by the image obtaining device; mirror the first image, thereby obtaining a second mirrored image; and determine the articulation angle between the first and the second vehicle sections based on a required level of relative rotation of the first image and the second mirrored image until the first image and the second mirrored image match each other. ### Claim 11 (depends on 10) The system of claim 10, wherein the image obtaining device is provided offset from the mid-longitudinal axis of the first vehicle section which intersects the first articulation joint, such as transversely offset and/or located above or below the first articulation joint. ### Claim 12 (depends on 10) The system of claim 10, wherein the image obtaining device is any one of a LIDAR, a RADAR, a SONAR and a camera, such as a stereo camera, a mono camera and a time-of-flight camera. ### Claim 13 (depends on 10) A vehicle comprising the system of claim 10. ### Claim 14 (depends on 1) A computer program comprising program code means for performing the steps of claim 1 when the program is run on a computer, such as on the processing unit of a system for determining an articulation angle of a vehicle combination comprising a first vehicle section, such as a truck, and a second vehicle section, such as a trailer or dolly unit, which are connected via a first articulation joint, wherein the system comprises an image obtaining device which is provided on the first vehicle section and configured to obtain images of the second vehicle section during use, wherein the system comprises a processing unit which is configured to: obtain a first image of the second vehicle section by the image obtaining device; mirror the first image, thereby obtaining a second mirrored image; and determine the articulation angle between the first and the second vehicle sections based on a required level of relative rotation of the first image and the second mirrored image until the first image and the second mirrored image match each other. ### Claim 15 (depends on 1) A computer readable medium carrying a computer program comprising program code means for performing the steps of claim 1 when the program product is run on a computer, such as on the processing unit of a system for determining an articulation angle of a vehicle combination comprising a first vehicle section, such as a truck, and a second vehicle section, such as a trailer or dolly unit, which are connected via a first articulation joint, wherein the system comprises an image obtaining device which is provided on the first vehicle section and configured to obtain images of the second vehicle section during use, wherein the system comprises a processing unit which is configured to: obtain a first image of the second vehicle section by the image obtaining device; mirror the first image, thereby obtaining a second mirrored image; and determine the articulation angle between the first and the second vehicle sections based on a required level of relative rotation of the first image and the second mirrored image until the first image and the second mirrored image match each other.