EP4367567A1 - Procédé et appareil de positionnement d'un drone d'inspection par rapport à une structure - Google Patents

Procédé et appareil de positionnement d'un drone d'inspection par rapport à une structure

Info

Publication number
EP4367567A1
EP4367567A1 EP21742083.5A EP21742083A EP4367567A1 EP 4367567 A1 EP4367567 A1 EP 4367567A1 EP 21742083 A EP21742083 A EP 21742083A EP 4367567 A1 EP4367567 A1 EP 4367567A1
Authority
EP
European Patent Office
Prior art keywords
camera
height
indicating
drone
distance
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
EP21742083.5A
Other languages
German (de)
English (en)
Inventor
Volodya Grancharov
Steven COMBES
Sigurdur Sverrisson
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Telefonaktiebolaget LM Ericsson AB
Original Assignee
Telefonaktiebolaget LM Ericsson AB
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Telefonaktiebolaget LM Ericsson AB filed Critical Telefonaktiebolaget LM Ericsson AB
Publication of EP4367567A1 publication Critical patent/EP4367567A1/fr
Pending legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G05—CONTROLLING; REGULATING
    • G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
    • G05D1/00—Control of position, course, altitude or attitude of land, water, air or space vehicles, e.g. using automatic pilots
    • G05D1/0094—Control of position, course, altitude or attitude of land, water, air or space vehicles, e.g. using automatic pilots involving pointing a payload, e.g. camera, weapon, sensor, towards a fixed or moving target
    • G—PHYSICS
    • G05—CONTROLLING; REGULATING
    • G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
    • G05D1/00—Control of position, course, altitude or attitude of land, water, air or space vehicles, e.g. using automatic pilots
    • G05D1/10—Simultaneous control of position or course in three dimensions
    • G05D1/101—Simultaneous control of position or course in three dimensions specially adapted for aircraft

Definitions

  • a mobile network operator may have many cell sites (e.g., locations at which a cell tower is located and antennas or other equipment may be connected to the tower).
  • the mobile network operatory may create a “digital twin” of the sites (i.e., a digital replica of the site), an example of which is a three- dimensional (3D) point cloud of the site.
  • Consistent data acquisition is the most important step in the process of creating digital twins of the cell sites.
  • 3D point clouds generated by means of imagery data obtained using a camera carried by an aerial vehicle (hereafter “drone”).
  • data consistency means correct drone position relative to the object of interest (e.g., the cell tower or other structure).
  • TSO Tower Site Overview
  • a method for positioning a drone with respect to a structure comprises a camera having an optical system (e.g., one or more lenses) and an image sensor configured to produce an image having a height and a width.
  • the method is performed by an apparatus and includes obtaining a height value, HT, indicating an estimated height of the structure.
  • the method also includes obtaining a set of parameters associated with the camera, the set of parameters includes a focal length parameter, f, indicating a focal length of the optical system of the camera and a height parameter, H , indicating said height of the image.
  • the method further includes determining, based on HT, f, and H , at least one of: i) a first distance value indicating a horizontal or vertical distance, dl, or ii) an angle value indicating an angle for the camera,
  • an apparatus for positioning a drone with respect to a structure comprises a camera having an optical system (e.g., one or more lenses) and an image sensor configured to produce an image having a height and a width.
  • the apparatus is configured to obtain a height value, HT, indicating an estimated height of the structure.
  • the apparatus is also configured to obtain a set of parameters associated with the camera, the set of parameters includes a focal length parameter, f, indicating a focal length of the optical system of the camera and a height parameter, H , indicating said height of the image.
  • the apparatus is also configured to determine, based on HT, f, and H , at least one of: i) a first distance value indicating a horizontal or vertical distance, dl, or ii) an angle value indicating an angle for the camera.
  • the apparatus may include memory and processing circuitry coupled to the memory.
  • a computer program comprising instructions which when executed by processing circuitry of an apparatus causes the apparatus to perform any of the methods disclosed herein.
  • a carrier containing the computer program wherein the carrier is one of an electronic signal, an optical signal, a radio signal, and a computer readable storage medium.
  • An advantage of the embodiments disclosed herein is that they improve the quality of data that is used to generate 3D point clouds of points-of-interest (e.g., a cell tower, a power pole, or other structure) and minimize the compute time required for their generation. It also minimizes the total cost of the process of creating digital twin of the point-of-interest as experienced pilots are not needed at the site.
  • points-of-interest e.g., a cell tower, a power pole, or other structure
  • FIG. 1 illustrates a photograph of a cell tower captured by an imaging system carried by a drone.
  • FIG. 2 illustrates a drone positioned in an optimal position with respect to a cell tower.
  • FIG. 3 illustrates a drone capturing an image of a cell tower while the drone is in an optimal position with respect to the cell tower.
  • FIG. 4 illustrates a side view of a cell tower and a drone.
  • FIG. 5 illustrates a drone moving from a position C to a position D, where D is one optimal position of the drone with respect to the cell tower.
  • FIG. 6 illustrates the done camera looking at the cell tower at an angle of Q.
  • FIG. 7 is a flowchart illustrating a process according to some embodiments.
  • FIG. 8 shows an apparatus according to some embodiments.
  • FIG. 1 illustrates a cell tower 101 as viewed from a drone 102 in a TSO orbit around cell tower 102.
  • the top and bottom of the tower are close to the upper and lower edge of an image 190 captured using a camera carried by drone 102.
  • Collecting images from a TSO orbit leads to accurate 3D point cloud generation.
  • the drone image has a width W and height H and the projection of the tower on the image plane has a height aH .
  • the scaling factor a is typically set to 0.9.
  • FIG. 2 illustrates drone 102 positioned in an optimal position with respect to cell tower 101 (as shown in FIG. 2, the optimal position is a horizontal distance of d from point (Xc, Yc,Zm ⁇ and a vertical distance of d from said point), and having its camera pointed downward from horizontal at an angle of 45 degrees towards the middle of the tower (i.e., point (Xc,Yc, Z m ⁇ ), and the TSO orbit is performed as a circle around the point (Xc,Yc, (Zm +d) ⁇ , which indicates the center of the tower on an XY plane.
  • the coordinate ZH is the altitude of the top of the tower
  • the coordinate ZM is 1/2 the altitude of the tower
  • Zo is the altitude of the bottom of the tower (ground level).
  • FIG. 3 The optimal distance of the drone to the cell tower is defined as the one at which the cell tower with height HT has a projection on the image plane aH .
  • FIG. 4 illustrates a side view of the tower and drone and show the following points: Z 0 , Z m , ZH, B, K, D, E, and F, the lower case letters in FIG. 4 (i.e., xi, X2, d, h, and f) are distances.
  • the points at ZH and Zo are projected to the top and bottom of the image plane.
  • xi BD
  • xi ZMB
  • X ⁇ +XI ZMD.
  • the TSO is a circle with a center ⁇ x c ,y c ⁇ , the symmetry allows for simplified definition, introduced in FIG. 4, which presents 2D projection (side view) of the 3D scene.
  • the embodiments aim to estimate the distance d of the drone, from the
  • FIG. 5 illustrates how to automatically position the drone in the optimal position for TSO orbit (i.e., it illustrates automatically moving the drone from position C to position D by having the drone fly vertically a distance of S).
  • the drone is automatically positioned to “see” the tower from 45° and the distance to the tower is such that the projection in the image plane has the desired dimensions.
  • the point D illustrated in FIG. 5, is just one example point on the TSO orbit.
  • any point in the orbit can be used to initialize the drone flight around the tower.
  • the 3D coordinates of the set of points satisfying the condition to be on the TSO orbit is: z 0 + z H x c + d sin(p) ,y c + d cos (f) , + d where f is an arbitrary angle.
  • x c + d sin(p) ,y c + d cos(p) ⁇ is a circle in XY- plane (see the coordinate system in FIG. 2) with center ⁇ x c ,y c ⁇ and radius d. Examples of points lying on the TSO orbit are:
  • the drone looking down at the cell tower at 45° is one preferred configuration for data acquisition at TSO orbit. External constraints, however, might require deviation of up to +/- 15° away from this preferred configuration.
  • the TSO orbit might be performed with the camera pointing down at angle Q in the range 30-60° as illustrated in FIG. 6.
  • the focal length f is denoted as DF
  • half of the image height H /2 is denoted by FE
  • half of the cell tower height HT/2 by ZMZH.
  • Deviation beyond 30-60° is not preferred because a deviation beyond this range may miss ground area around the cell tower (room with basebands, cable from there to the tower, road to enter the tower, etc.) or the essential side view of the installed telecom equipment (antennas, remote radio units (RRUs), etc.).
  • RRUs remote radio units
  • KZM horizontal and vertical drone offset for the TSO orbit might range from ca 0.6 to 1.7.
  • KD optimal distance from which the tower is correctly projected in the image plane through ZMD.
  • ZMD consist of two terms ZMB and BD. From triangle with vertices at points ZM, B, and ZH BD
  • FIG. 7 is a flowchart illustrating a process 700 according to an embodiment for use in positioning a drone with respect to a structure (e.g., cell tower 101 or other structure), where the drone comprises a camera having an optical system and an image sensor for producing images having a height and a width.
  • Process 700 may begin in step s702.
  • Step s702 comprises obtaining a height value, HT, indicating an estimated height of the structure.
  • Step s704 comprises obtaining a set of parameters associated with the camera, the set of parameters includes a focal length parameter, f, indicating a focal length of the optical system of the camera and a height parameter, H , indicating said height of the image.
  • Step s706 comprises determining, based on HT, f, and H , at least one of: i) a first distance value indicating a horizontal or vertical distance, dl, (e.g., distance d shown in FIG. 2, the distance between point K and point Z m in FIG. 5, or the distance between point K and point D in FIG. 5) or ii) an angle value indicating an angle for the camera, Q.
  • dl e.g., distance d shown in FIG. 2, the distance between point K and point Z m in FIG. 5, or the distance between point K and point D in FIG. 5
  • the process comprises determining the first distance value, dl, and dl is a horizontal distance value specifying a horizontal distance from a vertical axis of the structure.
  • the set of parameters further includes an angle value, Q, indicating an angle for the camera, and determining dl comprises calculating: dl cos Q, where a is a predetermined value.
  • the process also includes determining, based on HT, f, H , and Q, a second distance value indicating a vertical distance, d2.
  • determining d2 comprises
  • Q 30 degrees and 0
  • 0 45 degrees.
  • the process also includes configuring the drone to fly to a point, P, wherein the horizontal distance between P and the vertical axis of the structure is dl, and the distance from P to the bottom of the structure is (HT/2) + d2.
  • dl is a horizontal distance and determining dl 2 f ⁇ comprises calculating: dl + ⁇ -J, where a is a predetermined value.
  • the process may also include configuring the drone to fly to a point, P, wherein the horizontal distance between P and the vertical axis of the structure is dl, and the distance from P to the bottom of the structure is (HT/2) + dl .
  • the process includes determining the angle value, Q, and the process further includes, after determining the angle value, configuring the camera so that the camera points downward at an angle equal to Q. In some embodiments, determining
  • FIG. 8 is a block diagram of an apparatus 800, according to some embodiments, for performing process 700.
  • Apparatus 800 (or any portion thereof) may be carried by drone or may be remote from the drone. As shown in FIG.
  • apparatus 800 may comprise: processing circuitry (PC) 801, which may include one or more processors (P) 855 (e.g., a general purpose microprocessor and/or one or more other processors, such as an application specific integrated circuit (ASIC), field-programmable gate arrays (FPGAs), and the like), which processors may be co-located in a single housing or in a single data center or may be geographically distributed (i.e., apparatus 800 may be a distributed computing apparatus); at least one network interface 848 comprising a transmitter (Tx) 845 and a receiver (Rx) 847 for enabling apparatus 800 to transmit data to and receive data from other nodes connected to a network 110 (e.g., an Internet Protocol (IP) network) to which network interface 848 is connected (directly or indirectly) (e.g., network interface 848 may be wirelessly connected to the network 110, in which case network interface 848 is connected to an antenna arrangement); and a storage unit (a.k.a., “data storage system”) 808, which may include
  • a computer program product (CPP) 841 may be provided.
  • CPP 841 includes a computer readable medium (CRM) 842 storing a computer program (CP) 843 comprising computer readable instructions (CRI) 844.
  • CRM 842 may be a non-transitory computer readable medium, such as, magnetic media (e.g., a hard disk), optical media, memory devices (e.g., random access memory, flash memory), and the like.
  • the CRI 844 of computer program 843 is configured such that when executed by PC 801, the CRI causes apparatus 800 to perform steps described herein (e.g., steps described herein with reference to the flow charts).
  • apparatus 800 may be configured to perform steps described herein without the need for code. That is, for example, PC 801 may consist merely of one or more ASICs.

Landscapes

  • Engineering & Computer Science (AREA)
  • Aviation & Aerospace Engineering (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Remote Sensing (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Automation & Control Theory (AREA)
  • Length Measuring Devices By Optical Means (AREA)

Abstract

L'invention concerne un procédé (700) destiné à être utilisé pour positionner un drone (102) par rapport à une structure (101). Le drone comprend une caméra (103) ayant un système optique et un capteur d'image configuré pour produire une image (190) ayant une hauteur et une largeur. Le procédé comprend l'obtention (s702) d'une valeur de hauteur, HT, indiquant une hauteur estimée de la structure, d'un ensemble de paramètres associés à la caméra, l'ensemble de paramètres comprend un paramètre de longueur focale, f, indiquant une longueur focale du système optique de la caméra et un paramètre de hauteur, Hj, indiquant ladite hauteur de l'image. Le procédé comprend la détermination (s706), sur la base de HT, f et HJ, d'au moins un élément parmi : i) une première valeur de distance indiquant une distance horizontale ou verticale, dl, ou ii) une valeur d'angle indiquant un angle pour la caméra, Θ.
EP21742083.5A 2021-07-05 2021-07-05 Procédé et appareil de positionnement d'un drone d'inspection par rapport à une structure Pending EP4367567A1 (fr)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/EP2021/068489 WO2023280377A1 (fr) 2021-07-05 2021-07-05 Procédé et appareil de positionnement d'un drone d'inspection par rapport à une structure

Publications (1)

Publication Number Publication Date
EP4367567A1 true EP4367567A1 (fr) 2024-05-15

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Application Number Title Priority Date Filing Date
EP21742083.5A Pending EP4367567A1 (fr) 2021-07-05 2021-07-05 Procédé et appareil de positionnement d'un drone d'inspection par rapport à une structure

Country Status (2)

Country Link
EP (1) EP4367567A1 (fr)
WO (1) WO2023280377A1 (fr)

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
ES2684643T3 (es) * 2014-01-10 2018-10-03 Pictometry International Corp. Sistema y procedimiento de evaluación de estructura mediante aeronave no tripulada
US20160232792A1 (en) * 2015-02-06 2016-08-11 Izak Jan van Cruyningen UAV Inspection Flight Segment Planning

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WO2023280377A1 (fr) 2023-01-12

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