# US 10,372,986 B2 · Method and device for detecting an overhead cable from an aerial vessel > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,372,986 B2 - Document ID: US10372986B2 - Status: Granted - Kind: B2 - Application number: 15/537,971 - Filed: 2015-12-22 - Published: 2018-02-08 - Granted: 2019-08-06 - Earliest claimed: 2014-12-22 - Assignees: Kleon Prosjekt AS - Applicants: Kleon Prosjekt AS - Inventors: Aasmund Barikmo; Arne Sommerfelt - Web page: https://patentgrep.com/patent/US10372986B2 ## CPC - G06T 7/73: using feature-based methods - G06V 20/176: {Urban or other man-made structures} - G08B 21/18: Status alarms (G08B21/02 takes precedence) - G06T 2207/10016: Video; Image sequence - G06T 2207/10024: Color image - G06T 2207/10032: Satellite or aerial image; Remote sensing - G06T 2207/30184: Infrastructure - G06T: IMAGE DATA PROCESSING OR GENERATION, IN GENERAL - G06V: IMAGE OR VIDEO RECOGNITION OR UNDERSTANDING - G08B: SIGNALLING SYSTEMS, e.g. PERSONAL CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS ## Abstract A method and device for detecting an overhead cable from an aerial vessel, for instance from a helicopter in motion, and specifically for use in a landing preparing procedure. The method includes providing, from a camera arranged in the aerial vessel, a plurality of images of an area beneath the aerial vessel when the aerial vessel is in motion; detecting lines in the images; determining if the lines represent lines at ground level or lines at a level above ground level; and determining if a line at a level above ground level represents a possible overhead cable. The step of detecting lines in the images may include a modified SUSAN algorithm. The step of determining if the lines represent lines at ground level or lines above ground level may include parallax calculation. ## Claims ### Claim 1 A method for detecting an overhead cable from an aerial vessel, comprising: providing, from a camera arranged in said aerial vessel, a plurality of images of an area beneath said aerial vessel during motion of said aerial vessel, including providing, from said camera, a first and a second image at a first and a second point in time, respectively, while the aerial vessel is in motion between said first and second point in time; detecting lines in the first and second images; determining whether said lines represent lines at ground level or lines at a level above ground level; and determining whether a line at a level above ground level represents a possible overhead cable, wherein the step of determining whether said lines represent lines at ground level or lines at a level above ground level comprises: identifying pairs of lines belonging together, one, from said first image and one from said second image, respectively; identifying a background in each of said first and second images, associated with said pairs of lines; and determining if a particular line and background associated with said particular line have shifted more than a predetermined limit from said first to said second image, and, if so, determining if said particular line represents a line at a level above a ground level. ### Claim 2 (depends on 1) The method of claim 1, wherein the step of determining whether the lines represent lines at ground level or lines at a level above ground level comprises parallax calculation. ### Claim 3 (depends on 1) The method of claim 1, wherein the step of detecting lines in the first and second images comprises a modified SUSAN algorithm. ### Claim 4 (depends on 3) The method of claim 3, wherein the modified SUSAN algorithm comprises, for each of said images: providing a circular adjacent area around a center pixel, comparing the values of the center pixels with the values of other pixels within the adjacent area, defining a USAN area comprising the pixels in the adjacent area having values substantially similar to the center pixel, determining a geometry for the USAN area, and considering a line as detected when the geometry of the USAN area fulfils a predetermined requirement, determining a direction for the USAN area, and letting the direction of the USAN area determine the direction of the lines, the direction of the USAN area being determined by eigenvalue decomposition. ### Claim 5 (depends on 1) The method of claim 1, further comprising gathering position or motion data for the aerial vessel, and wherein the step of determining whether the line represents a line at ground level or a line at a level above ground level further employs said position or motion data. ### Claim 6 (depends on 1) The method of claim 1, wherein said plurality of images are color images, and wherein the step of detecting lines in the first and second images comprises assessing color of pixels in said first and second images. ### Claim 7 (depends on 1) The method of claim 1, performed during a landing preparing procedure for the aerial vessel. ### Claim 8 (depends on 1) The method of claim 1, wherein said camera is arranged in the aerial vessel in such a manner that the field of view of the camera is directed substantially perpendicular towards the ground. ### Claim 9 (depends on 1) The method of claim 1, further comprising issuing a warning when the overhead cable is detected. ### Claim 10 (depends on 1) The method of claim 1, performed by a processor device in a device for detecting the overhead cable from the aerial vessel. ### Claim 11 (depends on 1) Device for detecting the overhead cable from the aerial vessel, comprising the camera and a processing device, wherein said processing device is arranged to perform a method as defined in claim 1.