Supplementary device and method for position information of unmanned multi copters in GPS dead zones within railroad tunnels

Abstract

A position information supplementation device for an unmanned multi-copter in a GPS-unusable section within a railway tunnel according to an embodiment of the present invention comprises: an inertial navigation system; an unmanned multi-copter having the inertial navigation system built-in and having an infrared camera and an optical camera provided on one side; a plurality of passive markers installed in the railway tunnel, the surfaces of which are coated with a material that reflects infrared rays; a plurality of distance indicator beacons installed in the railway tunnel; and a navigation computer that sets a flight path of the unmanned multi-copter and performs navigation, generates first position information based on the distance between the unmanned multi-copter and a passive marker recognized in a first image acquired by the infrared camera and the distance between the passive markers, and generates second position information by combining the absolute position obtained from the distance indicator beacon recognized in a second image acquired by the optical camera with the current position and velocity of the unmanned multi-copter estimated through the inertial navigation system. and a position information supplementation unit that generates position information of an unmanned multicopter supplemented through the first position information and the second position information; and the navigation computer can change or maintain the flight path of the unmanned multicopter based on the supplemented position information of the unmanned multicopter.

Description

Technology Field

[0001] The present invention relates to a device and method for supplementing location information of an unmanned multi-copter in a GPS-unavailable section within a railway tunnel, and more specifically, to a device and method for supplementing location information of an unmanned multi-copter located in a GPS-unavailable section within a railway tunnel where GPS reception is impossible. Background Technology

[0002] Generally, conventional railway tunnel damage inspections proceeded in a sequence where a worker entered the tunnel, visually inspected the damaged areas, and then repaired the identified areas using equipment. However, railway tunnel damage inspections based on visual inspection have the problem that the identification of damaged areas may be inaccurate.

[0003] Accordingly, a method for inspecting railway tunnel damage using the automated flight of drones, such as unmanned multicopters, has recently been proposed. Using such drones offers the advantage of reducing labor costs compared to manual inspections.

[0004] However, since drones such as unmanned multicopters determine their location and perform navigation based on GPS, they are sensitive to GPS environments. Because railway tunnels are GPS-unavailable sections where GPS reception is impossible, devices and methods to supplement the drone's position are currently required for automatic flight. Prior art literature

[0005] Republic of Korea Registered Patent Publication No. 10-2073157 (Registered Jan. 29, 2020) Republic of Korea Registered Patent Publication No. 10-2525894 (Registered Apr. 21, 2023) Japanese Published Patent No. 2022-106383 (Published July 20, 2022) The problem to be solved

[0006] Accordingly, the present invention has been devised to solve the above-mentioned problems, and the objective of the present invention is to provide a device and method for supplementing the location information of an unmanned multi-copter located in a GPS-unavailable section within a railway tunnel where GPS reception is impossible, in order to conduct inspection of the railway tunnel using the unmanned multi-copter.

[0007] Specifically, the present invention aims to provide a device and method for supplementing the location information of an unmanned multi-copter located in a GPS-unavailable section within a railway tunnel where GPS reception is impossible, based on the location information of the unmanned multi-copter supplemented through the first and second location information, by generating first location information based on the distance between a plurality of passive markers recognized in the image of the unmanned multi-copter and the distance between the plurality of passive markers, generating second location information by combining location information obtained from a distance indicator beacon recognized in the image of the unmanned multi-copter and location information of the unmanned multi-copter estimated through an inertial navigation system, and then supplementing the location information of the unmanned multi-copter located in a GPS-unavailable section within a railway tunnel where GPS reception is impossible.

[0008] In addition, the present invention aims to provide a device and method for supplementing position information of an unmanned multi-copter in a GPS-unavailable section within a railway tunnel, which can estimate the absolute position and set the flight direction of the unmanned multi-copter through overhead line supports and tracks recognized in the image of the unmanned multi-copter.

[0009] However, the technical problems to be solved by the present invention are not limited to those mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art to which the present invention belongs from the description below. means of solving the problem

[0010] As a technical means for achieving the above-mentioned purpose, a position information supplementation device for an unmanned multi-copter in a GPS-unusable section within a railway tunnel according to an embodiment of the present invention comprises: an inertial navigation system; an unmanned multi-copter having the inertial navigation system built-in and equipped with an infrared camera and an optical camera on one side; a plurality of passive markers installed in the railway tunnel, the surfaces of which are coated with a material that reflects infrared rays; a plurality of distance indicator beacons installed in the railway tunnel; and a navigation computer that sets a flight path of the unmanned multi-copter and performs navigation, generates first position information based on the distance between the unmanned multi-copter and a passive marker recognized in a first image acquired by the infrared camera and the distance between the passive markers, and generates second position information by combining the absolute position obtained from the distance indicator beacon recognized in a second image acquired by the optical camera with the current position and velocity of the unmanned multi-copter estimated through the inertial navigation system. and a position information supplementation unit that generates position information of an unmanned multicopter supplemented through the first position information and the second position information; and the navigation computer can change or maintain the flight path of the unmanned multicopter based on the supplemented position information of the unmanned multicopter.

[0011] In addition, the first position information may be the x, y, and z coordinates of the unmanned multicopter.

[0012] And the second location information may be the latitude and longitude of the unmanned multicopter on a map inside the railway tunnel already established in the navigation computer.

[0013] Additionally, the unmanned multicopter may include a tag that receives signals periodically transmitted by the plurality of distance indicator beacons, converts the strength of the signals received from each distance indicator beacon into distances to each distance indicator beacon, and then combines them to calculate an absolute position.

[0014] And the above-mentioned plurality of distance indicator beacons may include a plurality of first distance indicator beacons installed on pillars arranged in a plurality within the railway tunnel; and a plurality of second distance indicator beacons installed on overhead line supports and tracks within the railway tunnel.

[0015] In addition, the navigation computer can estimate the extension direction of the overhead line support and the track based on the placement positions of the plurality of second distance indicator beacons, and adjust the flight direction of the unmanned multicopter based on the estimated extension direction of the overhead line support and the track.

[0016] And the above overhead line support and track may have an extension direction that coincides with the longitudinal direction of the above railway tunnel.

[0017] Additionally, the unmanned multicopter may include a gimbal for fixing or changing the shooting area of ​​the infrared camera and the optical camera.

[0018] And the above passive marker may include a first passive marker installed on one side of some of the columns arranged in plurality within the railway tunnel; a second passive marker installed on the inner side of the railway tunnel; and a third passive marker installed on the ceiling surface of the railway tunnel.

[0019] In addition, the distance indicator beacon may be installed on each of the multiple pillars arranged within the railway tunnel, and may be installed on the other side of a pillar that is orthogonal to one side of the pillar where the first passive marker is installed.

[0020] And a method for supplementing the position information of an unmanned multi-copter in a GPS-unavailable section within a railway tunnel according to an embodiment of the present invention, which is performed by a position information supplementing device of an unmanned multi-copter in a GPS-unavailable section within the railway tunnel, comprises: a) a step in which the unmanned multi-copter automatically flies within the railway tunnel along a flight path set by a navigation computer; b) a step in which an infrared camera provided on one side of the unmanned multi-copter photographs a plurality of passive markers whose surfaces are coated with a material that reflects infrared rays; c) a step in which an optical camera provided on one side of the unmanned multi-copter photographs a plurality of distance indicator beacons; d) a step in which the navigation computer generates first position information based on the distance between the unmanned multi-copter and a passive marker recognized in a first image acquired by the infrared camera and the distance between the passive markers; e) a step in which the navigation computer generates second position information by combining the absolute position obtained from a distance indicator beacon recognized in a second image acquired from the optical camera and the current position and velocity of the unmanned multicopter estimated through an inertial navigation device embedded in the unmanned multicopter; f) a step in which the position information supplementation unit generates position information of the unmanned multicopter supplemented through the first position information and the second position information; and g) a step in which the navigation computer applies the supplemented position information of the unmanned multicopter to the flight path of the unmanned multicopter to change or maintain the flight path of the unmanned multicopter; may be included.

[0021] In addition, a method for supplementing position information of an unmanned multicopter in a GPS-unavailable section within a railway tunnel according to one embodiment of the present invention may further include: h) a step of estimating the absolute position and adjusting the flight direction of the unmanned multicopter using the second image.

[0022] And the above step h) may include: h-1) a step in which the navigation computer recognizes overhead line supports and tracks within the railway tunnel in the second image; h-2) a step in which the tag converts the signal strength received from the second distance indicator beacon into a distance to each second distance indicator beacon and combines them to estimate the absolute position of the unmanned multicopter; h-3) a step in which the navigation computer estimates the extension direction of the supports and tracks based on the placement location of the second distance indicator beacons; and h-4) a step in which the navigation computer adjusts the flight direction of the unmanned multicopter so that the flight direction of the unmanned multicopter becomes parallel to the estimated extension direction of the supports and tracks. Effects of the invention

[0023] According to one embodiment of the present invention, by supplementing the location information of an unmanned multicopter located in a GPS-unusable section within a railway tunnel where GPS reception is impossible, the unmanned multicopter can be accurately moved to an area within the railway tunnel requiring damage inspection, thereby enabling accurate damage inspection within the railway tunnel.

[0024] According to one embodiment of the present invention, it is possible to estimate the absolute position and set the flight direction of an unmanned multicopter through overhead line supports and tracks installed in a railway tunnel, thereby facilitating damage inspection of a railway tunnel using an unmanned multicopter.

[0025] However, the effects obtainable from the present invention are not limited to those mentioned above, and other unmentioned effects will be clearly understood by those skilled in the art from the description below. Brief explanation of the drawing

[0026] FIG. 1 is a block diagram illustrating the schematic configuration of a position information supplementation device for an unmanned multicopter in a GPS-unused section within a railway tunnel according to one embodiment of the present invention. FIG. 2 is a drawing illustrating an unmanned multicopter according to one embodiment of the present invention. FIG. 3 is a diagram illustrating the interior of a railway tunnel equipped with passive markers and distance indicator beacons according to an embodiment of the present invention, and an automatic flight method of an unmanned multicopter using the same. FIG. 4 is a diagram illustrating a method for estimating the position and setting the flight direction of an unmanned multicopter according to an embodiment of the present invention. FIG. 5 is a flowchart illustrating the process of a method for supplementing location information of an unmanned multicopter in a GPS-unused section within a railway tunnel according to one embodiment of the present invention. FIG. 6 is a flowchart illustrating the detailed process of the first position information generation step according to one embodiment of the present invention. FIG. 7 is a flowchart illustrating the detailed process of the second location information generation step according to one embodiment of the present invention. FIG. 8 is a flowchart illustrating a process for estimating the absolute position and adjusting the flight direction of an unmanned multicopter according to one embodiment of the present invention. Specific details for implementing the invention

[0027] Hereinafter, embodiments of the present invention are described in detail with reference to the attached drawings so that those skilled in the art can easily implement the present invention. However, since the description of the present invention is merely an example for structural or functional explanation, the scope of the present invention should not be interpreted as being limited by the embodiments described in the text. That is, since the embodiments are subject to various modifications and may take various forms, the scope of the present invention should be understood to include equivalents capable of realizing the technical concept. Furthermore, the objectives or effects presented in the present invention do not imply that a specific embodiment must include all of them or only such effects; therefore, the scope of the present invention should not be understood as being limited by them.

[0028] The meaning of the terms described in this invention should be understood as follows.

[0029] Terms such as "first" and "second" are intended to distinguish one component from another, and the scope of rights shall not be limited by these terms. For example, the first component may be named the second component, and similarly, the second component may be named the first component. When a component is referred to as being "connected" to another component, it should be understood that it may be directly connected to that other component, or that there may be other components in between. Conversely, when a component is referred to as being "directly connected" to another component, it should be understood that there are no other components in between. Meanwhile, other expressions describing the relationship between components, such as "between" and "exactly between," or "adjacent to" and "directly adjacent to," shall be interpreted in the same manner.

[0030] A singular expression should be understood to include a plural expression unless the context clearly indicates otherwise, and terms such as "include" or "have" are intended to specify the existence of the set-up features, numbers, steps, actions, components, parts, or combinations thereof, and should be understood not to preclude the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0031] Unless otherwise defined, all terms used herein have the same meaning as generally understood by those skilled in the art to which this invention pertains. Terms defined in commonly used dictionaries should be interpreted as having meanings consistent with the context of the relevant technology and should not be interpreted as having an ideal or overly formal meaning unless explicitly defined in this invention.

[0033] Location information supplementation device for unmanned multicopters

[0034] Hereinafter, the configuration of a preferred embodiment will be described in detail with reference to the attached drawings.

[0035] FIG. 1 is a block diagram illustrating the schematic configuration of a position information supplement device for an unmanned multi-copter in a GPS-unused section within a railway tunnel according to an embodiment of the present invention, FIG. 2 is a drawing illustrating an unmanned multi-copter according to an embodiment of the present invention, FIG. 3 is a drawing for explaining the interior of a railway tunnel where passive markers and distance display beacons are installed according to an embodiment of the present invention and an automatic flight method of an unmanned multi-copter using the same, and FIG. 4 is a drawing for explaining the position estimation and flight direction setting method of an unmanned multi-copter according to an embodiment of the present invention.

[0036] Referring to FIG. 1, a location information supplement device (100) for an unmanned multicopter in a GPS-unused section within a railway tunnel according to one embodiment of the present invention may be configured with an unmanned multicopter (110), an inertial navigation device (120), a navigation computer (130), a passive marker (140), a distance display beacon (150), and a location information supplement unit (160).

[0037] The unmanned multicopter (110) is a device that performs damage inspection inside a railway tunnel while flying automatically in place of a worker, and may have an inertial navigation system (120) built in to estimate the current position and speed while flying automatically along a flight path.

[0038] The inertial navigation system (120) is a system that tracks the flight path (or movement path) of the unmanned multicopter (110) using the accelerometer and gyroscope of the unmanned multicopter (110), and can estimate the current position and speed of the unmanned multicopter (110) based on the acceleration and angular velocity of the unmanned multicopter (110).

[0039] The unmanned multicopter (110) of the present invention is equipped with an image acquisition means for acquiring a first image and a second image that the navigation computer (130) needs to generate location information of the unmanned multicopter (110) located in a GPS-unused section within a railway tunnel where GPS reception is impossible, and the image acquisition means of the present invention is as shown in FIG. 2.

[0040] Referring to FIG. 2, the unmanned multicopter (110) is provided with an image acquisition means on the upper side based on FIG. 2, and the device implementing the image acquisition means of the present invention is not limited, but as an example, the image acquisition means may be configured with an infrared camera (111), an optical camera (112), and a gimbal (113).

[0041] The infrared camera (111) is a camera that detects heat transfer or infrared (IR) generated from a heat-emitting object, and can obtain a first image, which is an infrared image, by photographing the interior of the railway tunnel while the unmanned multicopter (110) is flying automatically inside the railway tunnel to inspect damage to the railway tunnel.

[0042] The optical camera (112) is a camera that captures images using light rays, and can acquire a second image, which is an optical image, by capturing the interior of the railway tunnel while the unmanned multicopter (110) is flying automatically inside the railway tunnel to inspect damage to the railway tunnel.

[0043] These infrared cameras (111) and optical cameras (112) may be implemented in the form of separate camera devices that perform shooting through a separate control device, but are not limited thereto, and may also be implemented in the form of a camera module that performs shooting simultaneously and acquires first and second images simultaneously based on the operation being controlled through a single control device.

[0044] Meanwhile, although not shown in the drawings, the unmanned multicopter (110) of the present invention may be equipped with a communication unit (not shown) for communicating with a position information supplementary unit (150) so as to transmit the first position information and the second position information generated by the navigation computer (130) to the position information supplementary unit (160). However, if the position information supplementary unit (160) is embedded in the unmanned multicopter (110), the unmanned multicopter (110) can transmit the first position information and the second position information through the connection between the navigation computer (130) and the position information supplementary unit (160), so the configuration of the communication unit (not shown) may be omitted.

[0045] The gimbal (113) is a device for fixing or changing the shooting area of ​​the infrared camera (111) and the optical camera (112) while the unmanned multicopter (110) flies automatically along the flight path.

[0046] The navigation computer (130) can set the flight path of the unmanned multicopter (110) and perform navigation so that the unmanned multicopter (110) can fly automatically within the railway tunnel.

[0047] Additionally, the navigation computer (130) includes sensors such as GPS (GNSS), an inertial measurement unit (IMU), and a pressure sensor, and collects and processes data measured by the above sensors to estimate the position and attitude of the unmanned multicopter (110) and to plan and adjust the flight path of the unmanned multicopter (110).

[0048] The surface of the passive marker (140) may be coated with a material that reflects infrared light so that the navigation computer (130) can recognize it in the infrared image, which is the first image captured by the infrared camera (111).

[0049] At this time, the material coated on the surface of the passive marker (140) is not limited, but may be, for example, metal coatings that apply a metal layer or a diode layer to the surface, infrared reflective plastics designed to reflect infrared rays, infrared reflective sheets, reflective tapes, or infrared reflective paint.

[0050] In addition, the passive markers (140) are provided in multiple numbers and are installed inside the railway tunnel so that the navigation computer (130) can recognize them in the first image, and an example of the location where they are installed inside the railway tunnel is shown in FIG. 3.

[0051] Referring to FIG. 3, a plurality of passive markers (140) may be composed of a first passive marker (140a) installed on some of the columns arranged in a plurality within the railway tunnel, a second passive marker (140b) installed on the wall surface of the railway tunnel (inner side of the railway tunnel in FIG. 3), and a third passive marker (140c) installed on the ceiling surface of the railway tunnel (ceiling of the railway tunnel in FIG. 3).

[0052] Additionally, the multiple passive markers (140a, 140b, 140c) may have the same type of material coated on their surfaces to reflect infrared rays, but different infrared reflective materials may be coated considering the infrared reflection efficiency, etc.

[0053] As a specific example, the first passive marker (140a) may be a metal coating, the second passive marker (140b) may be an infrared reflective plastic, and the third passive marker (140c) may be a reflective tape.

[0054] And multiple passive markers (140a, 140b, 140c) can be placed at different locations within the railway tunnel so as to obtain accurate distance data when estimating the distance between the passive marker (140) and the unmanned multicopter (110).

[0055] The method by which these multiple passive markers (140a, 140b, 140c) are placed within the railway tunnel is not limited, but can be placed within the railway tunnel as shown in various embodiments below.

[0056] As a specific example, multiple passive markers (140) may be arranged sequentially with respect to the direction from the entrance side of the railway tunnel to the exit side, such as the first passive marker (140a) - second passive marker (140b) - third passive marker (140c) - first passive marker (140a) - second passive marker (140b) - third passive marker (140c)... and the first passive marker (140a), second passive marker (140b), and third passive marker (140c) may be arranged in a repeating order, and the arrangement order may be set in reverse.

[0057] As another specific example, multiple passive markers (140) are arranged sequentially in the same manner as in the example, such as first passive marker (140a) - first passive marker (140a) - second passive marker (140b) - second passive marker (140b) - third passive marker (140c) - third passive marker (140c)... based on the direction from the entrance side of the railway tunnel to the exit side, but after two or more passive markers of the same type are arranged, passive markers of a different type may be arranged sequentially, and the arrangement order may be set in reverse.

[0058] As another specific example, a plurality of passive markers (140) may be placed in a first area adjacent to the entrance side, a plurality of second passive markers (140b) in a second area adjacent to the rear end of the first area, and a plurality of third passive markers (140c) in a third area adjacent to the exit side, after the area of ​​the railway tunnel to be inspected for damage is divided into three parts, based on the direction from the entrance side of the railway tunnel. The order of placement may also be set in reverse.

[0059] The navigation computer (130) of the present invention recognizes the passive markers (140) through a material that reflects infrared rays coated on the surface of a plurality of passive markers (140) in a first image (infrared image), and can estimate the distance between the passive markers (140) and the unmanned multicopter (110) and the distance between the passive markers (140) through the following embodiments.

[0060] As a specific example, the navigation computer (130) recognizes one or more passive markers (140) in the first image and analyzes the pixel intensity of each recognized passive marker (140) to estimate the distance between the passive marker (140) and the unmanned multicopter (110) and the distance between the passive markers (140).

[0061] At this time, the navigation computer (130) can be machine-learned to recognize passive markers (140) in the first image and analyze the pixel intensity of the recognized passive markers (140).

[0062] Additionally, the navigation computer (130) can generate first position information of the unmanned multicopter (110) based on the distance between the estimated passive marker (140) and the unmanned multicopter (110) and the distance between the passive markers (140).

[0063] Meanwhile, the first position information of the present invention may be the x, y, and z coordinates of the unmanned multicopter (110), which are coordinates in three-dimensional space of the unmanned multicopter (110).

[0064] In this way, the first position information of the unmanned multicopter (110) generated from the navigation computer (130) can be transmitted to the position information supplementation unit (160).

[0065] The distance indicator beacons (150) are provided in multiple numbers and are installed inside the railway tunnel so that the navigation computer (130) can recognize them in the second image, and an example of the location where they are installed inside the railway tunnel is shown in FIG. 3.

[0066] Referring to FIG. 3, a plurality of distance indicator beacons (150) may be provided in multiple numbers, such as a first distance indicator beacon (150a), a second distance indicator beacon (150b), etc., installed on each pillar arranged within the railway tunnel, and each distance indicator beacon (150a, 150b) may be installed on the other side of a pillar that is orthogonal to one side of a pillar where a first passive marker (140a) is installed. However, the installation location of the distance indicator beacons (150a, 150b) is not limited to the other side of the pillar described above, and may be changed in various ways as long as it is a point recognizable by an optical camera (112).

[0067] The navigation computer (130) of the present invention recognizes a plurality of distance indicator beacons (150) in a second image (optical image), and can estimate the absolute position of an unmanned multicopter (110) using the plurality of distance indicator beacons (150) through the following embodiment.

[0068] As a specific example, a plurality of distance indicator beacons (150) periodically transmit signals toward a tag, and the tag converts the strength of the signal received from each distance indicator beacon (150) into a distance from each distance indicator beacon (150), and then combines them to calculate the absolute position of the unmanned multicopter (110).

[0069] In this way, a tag is required for the distance indicator beacon (150) to operate. The unmanned multicopter (110) of the present invention, although not shown in the drawing, may be equipped with a tag (not shown) that periodically receives a signal from the distance indicator beacon (150) while automatically flying along a flight path within a railway tunnel.

[0070] The navigation computer (130) of the present invention can generate second position information of the unmanned multicopter (110) by combining the absolute position of the unmanned multicopter (110) obtained from the tag and distance indicator beacon (150) with the current position and velocity of the unmanned multicopter (110) estimated through the inertial navigation device (120).

[0071] In this way, when the navigation computer (130) generates second location information, the absolute position measured by the tag and distance display beacon (150) as well as the inertial navigation device (120) is combined to prevent the unmanned multicopter (110) from deviating from the flight path due to the inaccurate estimation of the current position and speed of the unmanned multicopter (110), as the inertial navigation device (120) estimates the current position and speed of the unmanned multicopter (110) in a GPS-unused section within a railway tunnel where GPS reception is impossible.

[0072] Meanwhile, the second location information of the present invention may be the latitude and longitude of the unmanned multicopter (110) on a map inside a railway tunnel already established in the navigation computer (130).

[0073] In this way, the second location information of the unmanned multicopter (110) generated from the navigation computer (130) can be transmitted to the location information supplementation unit (160).

[0074] The location information supplementation unit (160) can generate supplemented location information of the unmanned multicopter (110) by combining the first location information and the second location information to supplement the location information of the unmanned multicopter (110) which may be inaccurate in a GPS-unused section within a railway tunnel where GPS reception is impossible.

[0075] The location information supplementary unit (160) of the present invention is a separate device from the unmanned multicopter (110) and is placed inside the railway tunnel in the same way as the unmanned multicopter (110) to receive the first location information and the second location information through the communication unit of the unmanned multicopter (110), but is not limited thereto and may be embedded in the unmanned multicopter (110).

[0076] The navigation computer (130) of the present invention can change or maintain the flight path of the unmanned multicopter (110) by applying the location information of the unmanned multicopter (110) that has been supplemented by the location information supplementation unit (160) to the flight path of the unmanned multicopter (110).

[0077] At this time, the navigation computer (130) can change the flight path of the unmanned multicopter (110) when there is a difference between the position information of the unmanned multicopter (110) in the preset flight path and the supplemented position information of the unmanned multicopter (110).

[0078] Meanwhile, the unmanned multicopter (110) recognizes the overhead line support (170) and the track (180) inside the railway tunnel shown in FIG. 4 in the second image (optical image), and can estimate the absolute position of the unmanned multicopter (110) through the recognized overhead line support (170) and the track (180).

[0079] Additionally, the navigation computer (130) can adjust the flight direction of the unmanned multicopter (110) based on the extension direction of the overhead line support (170) and the track (180).

[0080] At this time, the condition for adjusting the flight direction of the unmanned multicopter (110) based on the extension direction of the overhead line support (170) and the track (180) is that the extension direction of the overhead line support (170) and the track (180) is parallel to the longitudinal direction of the railway tunnel.

[0081] The method by which the unmanned multicopter (110) of the present invention recognizes the overhead line support (170) and the track (180) in the second image is not limited, but the overhead line support (170) and the track (180) can be recognized through the following embodiments.

[0082] As a specific example, when the distance indicator beacons (150) are defined as a plurality of first distance indicator beacons installed on each pillar installed within the railway tunnel, they may include a plurality of second distance indicator beacons installed on the overhead line support (170) and the track (180), although not shown in the drawing. Additionally, the plurality of second distance indicator beacons periodically transmit signals toward the tag of the unmanned multicopter (110), and the tag converts the strength of the signal received from each second distance indicator beacon into a distance to each second distance indicator beacon, and then combines them to calculate the absolute position of the unmanned multicopter (110).

[0083] At this time, the navigation computer (130) can estimate the extension direction of the overhead line support (170) based on the placement location of the second distance indicator beacons installed on the overhead line support (170). To this end, it is preferable that the second distance indicator beacons installed on the overhead line support (170) be installed at regular intervals on the long side frame (171) that is parallel to the longitudinal direction of the railway tunnel, among the long side frame (171) and the short side frame (172).

[0084] Below, we will explain in detail the process of the method (S100) for supplementing the location information of an unmanned multi-copter in a GPS-unusable section within a railway tunnel according to one embodiment of the present invention, which is performed on the location information supplementing device (100) of the unmanned multi-copter of the present invention described above.

[0086] Method to supplement location information of unmanned multicopters

[0087] FIG. 5 is a flowchart illustrating the process of a method for supplementing location information of an unmanned multicopter in a GPS-unused section within a railway tunnel according to an embodiment of the present invention, FIG. 6 is a flowchart illustrating the detailed process of a first location information generation step according to an embodiment of the present invention, FIG. 7 is a flowchart illustrating the detailed process of a second location information generation step according to an embodiment of the present invention, and FIG. 8 is a flowchart illustrating the process for estimating the absolute position and adjusting the flight direction of an unmanned multicopter according to an embodiment of the present invention.

[0088] Referring to FIG. 5, a method for supplementing location information of an unmanned multicopter (S100) according to one embodiment of the present invention may proceed in the order of an automatic flight step (S110), a passive marker shooting step (S120), a distance display beacon shooting step (S130), a first location information generation step (S140), a second location information generation step (S150), a step for generating location information of the supplemented unmanned multicopter (S160), and a flight path adjustment step of the unmanned multicopter (S170).

[0089] In the above automatic flight step (S110), the unmanned multicopter (110) can automatically fly within the railway tunnel along a flight path to perform damage inspection within the railway tunnel on behalf of the operator.

[0090] In this way, the above steps (S120~S170) can be performed while the unmanned multicopter (110) is flying automatically along the flight path.

[0091] In the above passive marker shooting step (S120), an infrared camera (111) is installed inside a railway tunnel and can obtain a first image by shooting at least one passive marker (140) among a plurality of first to third passive markers (140a, 140b, 140c) coated with a material that reflects infrared rays.

[0092] In the above distance indicator beacon shooting step (S130), the optical camera (112) can obtain a second image by shooting a plurality of distance indicator beacons (150) installed in the railway tunnel.

[0093] In the first position information generation step (S140) above, the navigation computer (130) can generate first position information, which is the x, y, and z coordinates of the unmanned multicopter (110) in three-dimensional space, using the first image acquired by the infrared camera (111), and the detailed process for generating the first position information is as shown in FIG. 6.

[0094] Referring to FIG. 6, the navigation computer (130) can recognize one or more passive markers (140) in the first image (S141).

[0095] After that, the navigation computer (130) can analyze the pixel intensity of each recognized passive marker (140) to estimate the distance between the passive marker (140) and the unmanned multicopter (110) and the distance between the passive markers (140) (S142).

[0096] After that, the navigation computer (130) can generate first position information of the unmanned multicopter (110) based on the distance between the estimated passive marker (140) and the unmanned multicopter (110) and the distance between the passive markers (140) (S143).

[0097] In the second position information generation step (S150) above, the navigation computer (130) can generate second position information, which is the latitude and longitude of the unmanned multicopter (110), on a map inside the railway tunnel already built in the navigation computer (130) using the second image acquired by the optical camera (112), and the detailed process for generating the second position information is as shown in FIG. 7.

[0098] Referring to FIG. 7, the navigation computer (130) can recognize a plurality of distance indicator beacons (150) in the second image (S151).

[0099] After that, multiple distance indicator beacons (150) periodically transmit signals toward the tag of the unmanned multicopter (110), and the tag converts the strength of the signal received from each distance indicator beacon (150) into a distance to each distance indicator beacon (150), and then combines them to calculate the absolute position of the unmanned multicopter (110) (S152).

[0100] After that, the navigation computer (130) can generate second position information of the unmanned multicopter (110) by combining the absolute position of the unmanned multicopter (110) obtained from the tag and distance indicator beacon (150) with the current position and velocity of the unmanned multicopter (110) estimated through the inertial navigation device (120) (S153).

[0101] In the step (S160) of generating location information of the above-mentioned supplemented unmanned multicopter, the location information supplementation unit (160) can generate location information of the supplemented unmanned multicopter (110) by combining the first location information and the second location information in order to supplement the location information of the unmanned multicopter (110) that may be inaccurate in a GPS-unused section within a railway tunnel where GPS reception is impossible.

[0102] In the flight path adjustment step (S170) of the above unmanned multicopter, the navigation computer (130) can change or maintain the flight path of the unmanned multicopter (110) by applying the supplemented location information of the unmanned multicopter (110) generated by the location information supplementation unit (160) to the flight path of the unmanned multicopter (110).

[0103] Referring to FIG. 8, the method for supplementing position information of an unmanned multicopter (S100) according to one embodiment of the present invention may additionally perform the step (S180) of estimating the absolute position and adjusting the flight direction of the unmanned multicopter (110) using a second image obtained from an optical camera (112).

[0104] In the step (S180) of estimating the absolute position and adjusting the flight direction of the above unmanned multicopter (110), the navigation computer (130) can recognize the overhead line support (170) and the track (180) inside the railway tunnel in the second image (S181).

[0105] After that, the tag of the unmanned multicopter (110) can convert the signal strength received from the distance indicator beacon (second distance indicator beacon) installed on the overhead line support (170) and the track (180) into the distance to each distance indicator beacon, and then combine them to calculate the absolute position of the unmanned multicopter (110) (S182).

[0106] After that, the navigation computer (130) can estimate the direction of extension of the overhead line support (170) and the track (180) based on the placement location of the distance indicator beacon (second distance indicator beacon) (S183).

[0107] After that, the navigation computer (130) can adjust the flight direction of the unmanned multicopter (110) so that the flight direction of the unmanned multicopter (110) becomes parallel to the extension direction of the estimated overhead line support (170) and the track (180) (S184).

[0108] At this time, the condition for adjusting the flight direction of the unmanned multicopter (110) based on the extension direction of the overhead line support (170) and the track (180) is that the extension direction of the overhead line support (170) and the track (180) is parallel to the longitudinal direction of the railway tunnel.

[0110] Effects according to the present invention

[0111] The location information supplementation device (100) of the unmanned multicopter of the present invention supplements the location information of the unmanned multicopter (110) located in a GPS-unusable section within a railway tunnel where GPS reception is impossible, thereby enabling the unmanned multicopter (110) to be accurately moved to an area within the railway tunnel where damage inspection is required, and thereby enables accurate damage inspection within the railway tunnel.

[0112] The position information supplement device (100) of the unmanned multicopter of the present invention makes it possible to estimate the absolute position and set the flight direction of the unmanned multicopter (110) through the overhead line support (170) and track (180) installed in the railway tunnel, thereby enabling easy inspection of damage to the railway tunnel using the unmanned multicopter (110).

[0114] As described above, the detailed description of the preferred embodiments of the present invention disclosed is provided to enable those skilled in the art to implement and practice the present invention. Although the present invention has been described with reference to preferred embodiments, those skilled in the art will understand that various modifications and changes can be made to the present invention without departing from the scope of the invention. For example, those skilled in the art may utilize each configuration described in the embodiments described above in combination with one another. Accordingly, the present invention is not intended to be limited to the embodiments shown herein, but to be given the broadest scope consistent with the principles and novel features disclosed herein.

[0115] The present invention may be embodied in other specific forms without departing from the technical spirit and essential features of the invention. Accordingly, the above detailed description should not be interpreted restrictively in all respects but should be considered exemplary. The scope of the invention shall be determined by a reasonable interpretation of the appended claims, and all modifications within the equivalent scope of the invention are included within the scope of the invention. The invention is not intended to be limited to the embodiments shown herein, but to be given the broadest possible scope consistent with the principles and novel features disclosed herein. Furthermore, embodiments may be constructed by combining claims that are not explicitly related in the claims, or included as new claims through amendments made after filing. Explanation of the symbols

[0116] 100: Location information supplementation device for unmanned multicopters, 110: Unmanned multicopter, 111: Infrared camera, 112: Optical camera, 120: Inertial navigation system, 130: Navigation computer, 140: Passive Marker, 140a: 1st Passive Marker, 140b: 2nd passive marker, 140c: 3rd passive marker, 150: Distance indicator beacon, 160: Location information supplementary unit, 170: Overhead line support, 171: Long side frame, 172: Short side frame, 180: Track.

Claims

Claim 1 An inertial navigation system; an unmanned multicopter in which the inertial navigation system is built-in and an infrared camera and an optical camera are provided on one side; a plurality of passive markers installed in multiple locations within a railway tunnel, the surfaces of which are coated with a material that reflects infrared rays; a plurality of distance indicator beacons installed in multiple locations within the railway tunnel; a navigation computer that sets the flight path of the unmanned multicopter and performs navigation, generates first position information based on the distance between the unmanned multicopter and a passive marker recognized in a first image acquired by the infrared camera and the distance between the passive markers, and generates second position information by combining the absolute position obtained from the distance indicator beacon recognized in a second image acquired by the optical camera with the current position and velocity of the unmanned multicopter estimated through the inertial navigation system; A location information supplementation unit that generates location information of an unmanned multi-copter supplemented through the first location information and the second location information; wherein the navigation computer changes or maintains the flight path of the unmanned multi-copter based on the supplemented location information of the unmanned multi-copter, and the second location information is the latitude and longitude of the unmanned multi-copter on a map inside the railway tunnel already established in the navigation computer, and the unmanned multi-copter includes a tag that receives signals periodically transmitted by the plurality of distance indicator beacons, converts the strength of the signals received from each distance indicator beacon into a distance to each distance indicator beacon, and combines them to calculate an absolute position. Claim 2 A device for supplementing location information of an unmanned multicopter in a GPS-unusable section within a railway tunnel, characterized in that, in claim 1, the first location information is the x, y, and z coordinates of the unmanned multicopter. Claim 3 delete Claim 4 delete Claim 5 A position information supplementation device for an unmanned multicopter in a GPS-unusable section within a railway tunnel, characterized in that, in claim 1, the plurality of distance indicator beacons comprises: a plurality of first distance indicator beacons installed on pillars arranged in a plurality within the railway tunnel; and a plurality of second distance indicator beacons installed on overhead line supports and tracks within the railway tunnel. Claim 6 A position information supplementation device for an unmanned multicopter in a GPS-unusable section within a railway tunnel, characterized in that, in claim 5, the navigation computer estimates the extension direction of the overhead line support and the track based on the placement positions of the plurality of second distance indicator beacons, and adjusts the flight direction of the unmanned multicopter based on the estimated extension direction of the overhead line support and the track. Claim 7 A position information supplementation device for an unmanned multicopter in a GPS-unusable section within a railway tunnel, characterized in that, in claim 6, the overhead line support and the track have an extension direction that coincides with the longitudinal direction of the railway tunnel. Claim 8 A position information supplementation device for an unmanned multicopter in a GPS-unusable section within a railway tunnel, characterized in that, in claim 1, the unmanned multicopter includes a gimbal for fixing or changing the shooting area of ​​the infrared camera and the optical camera. Claim 9 A position information supplementation device for an unmanned multicopter in a GPS-unusable section within a railway tunnel, characterized in that, in claim 1, the passive marker comprises: a first passive marker installed on one side of some of the columns arranged in plurality within the railway tunnel; a second passive marker installed on the inner side of the railway tunnel; and a third passive marker installed on the ceiling surface of the railway tunnel. Claim 10 A location information supplementation device for an unmanned multicopter in a GPS-unusable section within a railway tunnel, characterized in that, in claim 9, the distance indicator beacon is installed on each of the multiple pillars arranged within the railway tunnel, and is installed on the other side of a pillar that is orthogonal to one side of the pillar where the first passive marker is installed. Claim 11 a) a step in which an unmanned multicopter automatically flies within a railway tunnel along a flight path set by a navigation computer; b) a step in which an infrared camera provided on one side of the unmanned multicopter photographs a plurality of passive markers whose surfaces are coated with a material that reflects infrared rays; c) a step in which an optical camera provided on one side of the unmanned multicopter photographs a plurality of distance indicator beacons; d) a step in which the navigation computer generates first position information based on the distance between the unmanned multicopter and the passive markers recognized in the first image acquired by the infrared camera and the distance between the passive markers; e) a step in which the navigation computer generates second position information by combining the absolute position obtained from the distance indicator beacons recognized in the second image acquired by the optical camera with the current position and velocity of the unmanned multicopter estimated through an inertial navigation system embedded in the unmanned multicopter; f) a step in which a position information supplementation unit generates position information of the unmanned multicopter supplemented through the first position information and the second position information; and g) a step in which the navigation computer applies the supplemented position information of the unmanned multicopter to the flight path of the unmanned multicopter to change or maintain the flight path of the unmanned multicopter; wherein the second position information is the latitude and longitude of the unmanned multicopter on a map inside the railway tunnel already constructed in the navigation computer, and the unmanned multicopter includes a tag that receives signals periodically transmitted by the plurality of distance indicator beacons, converts the strength of the signal received from each distance indicator beacon into a distance to each distance indicator beacon, and combines them to calculate an absolute position; characterized in that the method for supplementing position information of an unmanned multicopter in a GPS-unusable section within a railway tunnel. Claim 12 A method for supplementing location information of an unmanned multicopter in a GPS-unusable section within a railway tunnel, characterized in that, in claim 11, the first location information is the x, y, and z coordinates of the unmanned multicopter. Claim 13 delete Claim 14 A method for supplementing position information of an unmanned multicopter in a GPS-unusable section within a railway tunnel, characterized by further including, in claim 11, the step of estimating the absolute position and adjusting the flight direction of the unmanned multicopter using the second image. Claim 15 delete Claim 16 A method for supplementing location information of an unmanned multicopter in a GPS-unusable section within a railway tunnel, characterized in that, in claim 14, the plurality of distance indicator beacons comprises: a plurality of first distance indicator beacons installed on pillars arranged in a plurality within the railway tunnel; and a plurality of second distance indicator beacons installed on overhead line supports and tracks within the railway tunnel. Claim 17 In claim 16, the above step h) comprises: h-1) a step in which the navigation computer recognizes overhead line supports and tracks within the railway tunnel in the second image; h-2) a step in which the tag converts the signal strength received from the second distance indicator beacon into a distance to each second distance indicator beacon and combines them to estimate the absolute position of the unmanned multicopter; h-3) a step in which the navigation computer estimates the extension direction of the supports and tracks based on the placement location of the second distance indicator beacons; and h-4) a step in which the navigation computer adjusts the flight direction of the unmanned multicopter so that the flight direction of the unmanned multicopter becomes parallel to the estimated extension direction of the supports and tracks; characterized in that the method for supplementing position information of an unmanned multicopter in a GPS-unusable section within a railway tunnel. Claim 18 A method for supplementing position information of an unmanned multicopter in a GPS-unusable section within a railway tunnel, characterized in that, in claim 17, the overhead line support and the track have an extension direction that coincides with the longitudinal direction of the railway tunnel.

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