Estimation system for estimating self-position and / or attitude of unmanned aerial vehicle, flight control system, unmanned aerial vehicle, program, and recording medium

Abstract

Provided is a system for estimating the location of an unmanned aerial vehicle in the case when autonomous flight is carried out by the unmanned aerial vehicle within the interior space of a structure such as a tunnel.　In the present invention, a self-location estimation system comprises a transverse cross-sectional position / attitude estimation unit which matches a circle to transverse cross-sectional measurement data acquired by a transverse cross-sectional measurement data acquisition unit, estimates a first position of the center point O1' of the circle in a relative coordinate system that uses the unmanned aerial vehicle inside the transverse cross section as a reference, estimates a second position of the center point O2' of piping in the relative coordinate system on the basis of the transverse cross-sectional measurement data, estimates a direction of the second position with respect to the first position in the relative coordinate system, and estimates the self-location and attitude of the unmanned aerial vehicle in an absolute coordinate system that uses the direction of the center of the piping with respect to the center of the tunnel as a reference axis.

Description

[Technical field]

[0001] The present invention relates to an estimation system for estimating the self-position and / or attitude of an unmanned aerial vehicle, a flight control system, an unmanned aerial vehicle, a program, and a recording medium. [Background technology]

[0002] Recently, attempts have been made to use drones to inspect structures such as tunnels. Drones can estimate their own position using GPS satellite positioning information and fly autonomously along a flight plan route, but it is difficult to obtain accurate position information using GPS in the interior space of structures such as tunnels. Therefore, in such environments, a technology has been proposed to use laser SLAM to estimate their own position as an alternative to GPS-based self-position estimation (Non-Patent Document 1 below). Laser SLAM is a technology that uses LIDAR, which irradiates laser light to the surroundings and measures the distance to the irradiated object based on the time it takes for the irradiated light to be received, and estimates the self-position and map in parallel based on the output from the LIDAR. [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] Kenzo Nonami, "All about drone industrial applications", Ohmsha, February 2018, pp.79-85 Summary of the Invention [Problem to be solved by the invention]

[0004] In self-localization using Laser SLAM, the vehicle's position is estimated by referring to a map based on the measurement data from the LIDAR. However, the inner walls of vertically extending tunnels (tanks) are often rotationally symmetric, such as circular, and the map itself is also rotationally symmetric, making it difficult to estimate the vehicle's position with high accuracy.

[0005] Therefore, one of the objectives of the present invention is to provide a system and method for estimating the position and / or attitude of an unmanned aerial vehicle when the unmanned aerial vehicle is flying autonomously within the interior space of a structure with a rotationally symmetric cross-sectional shape, such as a vertically extending tunnel (tank). [Means for solving the problem]

[0006] One aspect of the present invention is an estimation system for estimating the self-position and / or attitude of an unmanned aerial vehicle, the unmanned aerial vehicle including a cross section measuring device that measures a spatial shape based on a predetermined direction of the unmanned aerial vehicle in a cross section that intersects a longitudinal flight path of the unmanned aerial vehicle and generates cross section measurement data, the cross section measurement data acquisition unit acquiring the cross section measurement data generated by the cross section measuring device when the unmanned aerial vehicle flies through an internal space of a structure in which an internal space extending longitudinally along a predetermined path is formed and an internal structure extending longitudinally within the internal space is provided, and the cross section measurement data acquisition unit acquiring the cross section measurement data generated by the cross section measuring device. The present invention provides an estimation system comprising: a relative coordinate system calculation unit that matches a rotationally symmetric first predetermined shape corresponding to the cross-sectional shape of the inner wall surface of the structure to the cross-sectional measurement data acquired by the measurement data acquisition unit, estimates a first position of a first feature point that is the center of the matched first predetermined shape in a relative coordinate system based on the unmanned aerial vehicle in the cross-section, estimates a second position of a second feature point associated with the internal structure in the relative coordinate system based on the cross-sectional measurement data acquired by the cross-sectional measurement data acquisition unit, and calculates the direction of the second position relative to the first position in the relative coordinate system.

[0007] In one aspect of the present invention, the unmanned aerial vehicle may further be provided with an in-transverse plane position / attitude estimation unit that estimates the unmanned aerial vehicle's position and / or attitude in an absolute coordinate system whose reference axis is the direction of a point corresponding to a second characteristic point of the internal structure relative to a point corresponding to a first characteristic point of the structure in the transverse plane.

[0008] In one aspect of the present invention, the transverse plane position / attitude estimation unit can be configured to coordinate transform the relative coordinate system into an absolute coordinate system so that the direction of a second position relative to a first position in the relative coordinate system corresponds to a reference axis, and to estimate the heading direction of the unmanned aerial vehicle in the absolute coordinate system.

[0009] In one embodiment of the present invention, the transverse plane position / attitude estimation unit performs coordinate transformation so that the direction of a second position relative to a first position in the relative coordinate system corresponds to a reference axis, and the first position in the relative coordinate system corresponds to coordinates in an absolute coordinate system corresponding to a first feature point of the structure, and can estimate coordinates in the absolute coordinate system of the unmanned aerial vehicle.

[0010] In one aspect of the invention, the first predetermined shape can be either a circle, an oval, or a rectangle.

[0011] In one aspect of the present invention, a gap area where no data exists is identified within an area near a matched first predetermined shape in the cross-sectional measurement data, and the intersection of an approximate bisector of the angular range of the gap area relative to the unmanned aerial vehicle with a circle having a radius equal to the distance between a predetermined first feature point and a second feature point and centered on the first feature point is estimated as the second position.

[0012] In one aspect of the present invention, the relative coordinate system calculation unit can match a second predetermined shape corresponding to a portion corresponding to an internal structure to the cross-sectional measurement data, and estimate the relative coordinates of a predetermined point in the matched second predetermined shape as the second position.

[0013] In one aspect of the present invention, the cross-sectional measurement data is discrete data, and the relative coordinate system calculation unit can remove outliers in the discrete data and perform matching.

[0014] One aspect of the present invention provides a flight control system for an unmanned aircraft, which includes the above-mentioned estimation system and a flight control unit that flies the unmanned aircraft along a set flight plan route based on the unmanned aircraft's own position and / or attitude estimated by the estimation system.

[0015] One aspect of the present invention provides an unmanned aerial vehicle having the above-described estimation system.

[0016] One aspect of the present invention provides an unmanned aerial vehicle having a flight control system.

[0017] One aspect of the present invention is an estimation method for estimating the self-position and / or attitude of an unmanned aerial vehicle by a computer, the unmanned aerial vehicle including a cross section measuring device that measures a spatial shape based on a predetermined direction of the unmanned aerial vehicle in a cross section that intersects the longitudinal flight path of the unmanned aerial vehicle and generates cross section measurement data, and a cross section measurement data acquisition step of acquiring the cross section measurement data generated by the cross section measuring device when the unmanned aerial vehicle flies through an internal space of a structure in which an internal space is formed that extends longitudinally along the predetermined path and in which an internal structure extending longitudinally is provided within the internal space; The present invention provides a self-location estimation method including: a first feature point estimation step of matching a rotationally symmetric first predetermined shape corresponding to the cross-sectional shape of the inner wall surface of the structure to the acquired cross-section measurement data, and estimating a first position of a first feature point that is the center of the matched first predetermined shape in a relative coordinate system based on the unmanned aerial vehicle in the cross-section; a second feature point estimation step of estimating a second position of a second feature point associated with the internal structure in the relative coordinate system based on the acquired cross-section measurement data; and a calculation step of calculating the direction of the second position relative to the first position in the relative coordinate system.

[0018] One aspect of the present invention provides a program for causing a computer to execute the above-described method.

[0019] One aspect of the present invention provides a computer-readable recording medium having the above-mentioned program recorded thereon. Effect of the Invention

[0020] According to the present invention, a system and method can be provided for estimating the position and / or attitude of an unmanned aerial vehicle when the unmanned aerial vehicle is flying autonomously within the interior space of a structure with a rotationally symmetric cross-sectional shape, such as a vertically extending tunnel (tank). [Brief description of the drawings]

[0021] [Figure 1] FIG. 1 is an external view of a multicopter, which is an example of an unmanned aerial vehicle (multicopter) according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a diagram illustrating a flight control system for the unmanned aerial vehicle shown in FIG. [Diagram 3] 2 is a block diagram showing the configuration of an information processing unit of the unmanned aerial vehicle shown in FIG. 1. [Figure 4] 2 is a diagram illustrating a hardware configuration of an information processing unit of the unmanned aerial vehicle shown in FIG. 1. [Figure 5A] 4 is a horizontal cross-section of a tunnel showing the tunnel and the flight plan path in one embodiment of the present invention. FIG. [Figure 5B] 5B is a cross-sectional view of FIG. 5A. [Figure 6] FIG. 2 is a horizontal cross-sectional view showing an area that can be measured by the cross-section measuring device. [Figure 7] 13 is a diagram showing how the optical cross-sectional position estimating unit matches a circle corresponding to the inner wall surface of the tunnel with the longitudinal cross-sectional data. FIG. [Figure 8] FIG. 13 illustrates a comparison of the matched circle model with cross-sectional measurement data. [Figure 9] 13 is a diagram showing how to identify the intersection between a circle C3 on which the center of a pipe is located and a bisector L3. FIG. [Figure 10] The relative coordinate system based on the unmanned aerial vehicle is converted to an absolute coordinate system. [Figure 11]4 is a flowchart showing the flow of autonomously flying the unmanned aerial vehicle shown in FIG. 1 inside a tunnel and photographing the inner wall surface of the tunnel. [Figure 12] 2 is a flowchart showing in detail the flow of autonomous flight by the unmanned aerial vehicle shown in FIG. 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. However, the present invention is not limited to the specific embodiment described below, and various embodiments can be taken within the scope of the technical concept of the present invention. For example, the unmanned aerial vehicle of the present invention is not limited to the multicopter shown in FIG. 1, but may be any unmanned aerial vehicle such as a rotorcraft or a fixed-wing aircraft. In addition, the system configuration of the unmanned aerial vehicle 1 is not limited to that shown in the figure, and may be any configuration as long as the same operation is possible. For example, the operation performed by multiple components may be performed by a single component, such as integrating the function of a communication circuit into a flight control unit, or the operation performed by a single component may be performed by multiple components, such as distributing the function of a main calculation unit to multiple calculation units. In addition, various data stored in the memory of the unmanned aerial vehicle 1 may be stored in a different location from the memory, and information recorded in various memories may be stored by distributing one type of information to multiple types, or multiple types of information may be stored together in one type.

[0023] In the following description, an unmanned aerial vehicle autonomously flies through a tunnel extending in the vertical direction and captures images of the inner wall surface of the tunnel. The shape of the tunnel is known from blueprints and the like, and in this embodiment, the internal space within the tunnel has an inner wall surface that is circular in a horizontal cross section (transverse cross section) and extends in the vertical direction (lengthwise) on the same cross section. In addition, within the tunnel, a pipe with a circular horizontal cross section extends in the vertical direction.

[0024] FIG. 1 is an external view of a multicopter, which is an example of an unmanned aerial vehicle (multicopter) 1 according to an embodiment of the present invention. The unmanned aerial vehicle 1 includes, in terms of appearance, a control unit 101, six motors 102 driven by control signals from the control unit 101, six rotors (rotating wings) 103 that rotate by driving the respective motors 102 to generate lift, six arms 104 connecting the control unit 101 and the respective motors 102, and landing legs 105 that support the unmanned aerial vehicle when landing. The number of motors 102, rotors 103, and arms 104 may each be three or more, such as three or four. The six motors 102 are rotated by control signals from the control unit 101, and the rotation speed of each of the six rotors 103 is thereby controlled, thereby controlling the flight of the unmanned aerial vehicle 1, such as ascent, descent, forward / backward / left / right flight, and turning.

[0025] In addition, a pedestal 106 is attached above the control unit 101. A camera 108 for photographing an object at high resolution is attached to the pedestal 106 via a support member 107 that rotatably supports the camera 108.

[0026] In addition, a cross-section measuring device (horizontal section LIDAR) 109 for measuring the shape of the surrounding space in a horizontal section (transverse section) is provided in front of the base 106. In this embodiment, the cross-section measuring device 109 is a horizontal section LIDAR, which irradiates a pulsed laser at a predetermined angular interval around the entire circumference around a vertical axis in a horizontal plane while the unmanned aerial vehicle 1 is landing or hovering, and receives the laser reflected by an object in the surrounding space, thereby measuring the distance to the object in the surrounding space based on the time from irradiation to reception. By driving the cross-section measuring device 109 while the unmanned aerial vehicle 1 is flying in the tunnel, the cross-section measuring device 109 generates cross-section measurement data regarding the horizontal cross-sectional shape (cross-sectional shape) of the inner wall surface of the tunnel (shape of the tunnel inner space). The cross-section measurement data is, for example, a collection of discrete data in polar coordinates based on the front of the unmanned aerial vehicle 1. Note that in this embodiment, a horizontal section LIDAR is used as the cross-section measuring device 111, but the present invention is not limited to this. For example, by capturing images of the entire cross section with a visible light camera centered on the unmanned aerial vehicle, integrating the captured images, and creating a 3D model, it is possible to measure the shape of the inner wall of the tunnel within the cross section and estimate the vehicle's own position within the cross section. SfM is a known algorithm for creating such a 3D model, and Dense Visual SLAM is a known algorithm for estimating the vehicle's own position using SfM.

[0027] An altimeter 110 is provided above the control unit 101. A barometric altimeter that measures altitude based on air pressure is suitable as the altimeter. The unmanned aerial vehicle 1 also has an antenna 117.

[0028] Fig. 2 is a diagram showing a flight control system of the unmanned aerial vehicle shown in Fig. 1. The flight control system 200 of the unmanned aerial vehicle 1 includes a control unit 101, a motor 102 electrically connected to the control unit 101, a rotor 103 mechanically connected to the motor 102, a camera 108, a cross-section measuring device 109, an altimeter 110, and an IMU 111.

[0029] The control unit 101 is configured to process information for controlling the flight of the unmanned aerial vehicle 1 and to control the electrical signals for that purpose, and is typically a unit configured with circuits required to realize such functions by arranging and wiring various electronic components on a board. The control unit 101 further comprises an information processing unit 120, a communication circuit 121, a control signal generating unit 122, a speed controller 123, and an interface 125.

[0030] Camera 108 is a camera for capturing images of an object (in this embodiment, the inner wall of a tunnel) at high resolution. Camera 108 is attached to base 106 via support member 107 that rotatably supports camera 108, making it possible to change the imaging direction. Camera 108 acquires image data of its imaging range while unmanned aerial vehicle 1 is flying, and the acquired images are stored in a storage device such as a memory described below. The images are typically video images consisting of a series of still images.

[0031] The IMU 111 is an inertial measurement unit that detects translational motion using an acceleration sensor and rotational motion using an angular velocity sensor (gyro). Furthermore, the IMU 111 can calculate a velocity by integrating the translational motion (acceleration) detected by the acceleration sensor, and can calculate a travel distance (position) by integrating the velocity. Similarly, the IMU 111 can calculate an angle (attitude) by integrating the rotational motion (angular velocity) detected by the angular velocity sensor.

[0032] Antenna 117 is an aerial for receiving radio signals including information and various data for piloting and controlling unmanned aerial vehicle 1, and for transmitting radio signals including telemetry signals from unmanned aerial vehicle 1.

[0033] The communication circuit 121 is an electronic circuit, typically a wireless signal processing IC, for demodulating the wireless signals received through the antenna 117 to receive control signals, various data, and the like for the unmanned aerial vehicle 1, and inputting the control signals and various data to the information processing unit 120, and for generating wireless signals for carrying telemetry signals and the like output from the unmanned aerial vehicle 1. Note that, for example, the communication of control signals and the communication of control signals and various data may be performed by different communication circuits in different frequency bands. For example, it is possible to adopt a configuration in which communication with a transmitter of a controller (transmitter) for manual operation is performed at a frequency of 950 MHz, and data communication is performed at a frequency of 2 GHz, 1.7 GHz, 1.5 GHz, or 800 MHz.

[0034] Control signal generating unit 122 is configured to convert control command value data obtained by calculation by information processing unit 120 into a pulse signal (such as a PWM signal) representing a voltage, and is typically an IC including an oscillator circuit and a switching circuit. Speed ​​controller 123 is configured to convert the pulse signal from control signal generating unit 122 into a drive voltage that drives motor 102, and is typically a smoothing circuit and an analog amplifier. Although not shown, unmanned aerial vehicle 1 is equipped with a power supply system including a battery device such as a lithium polymer battery or a lithium ion battery, and a power distribution system to each element.

[0035] The interface 125 is a configuration that electrically connects the information processing unit 120 to functional elements such as the camera 108, the cross-section measuring device 109, the altimeter 110, and the IMU 111 by converting the form of signals so that signals can be transmitted and received between them. For convenience of explanation, the interface is shown as one configuration in the drawings, but it is normal to use a different interface depending on the type of functional element to be connected. Also, depending on the type of signal input / output of the functional element to be connected, the interface 125 may not be necessary. Even in the case of the information processing unit 120 in FIG. 2 that is connected without the interface 125, depending on the type of signal input / output of the functional element to be connected, an interface may be necessary.

[0036] FIG. 4 is a block diagram showing the configuration of the information processing unit of the unmanned aerial vehicle shown in FIG. 1. As shown in FIG. 3, the information processing unit 120 includes a cross-sectional shape data storage unit 130, a flight path data storage unit 131, a relative coordinate system calculation unit 136, a transverse plane position / attitude estimation unit 132, a self-position data generation unit 133, a flight control unit 134, and a transverse plane measurement data acquisition unit 135. In this embodiment, the cross-sectional shape data storage unit 130, the relative coordinate system calculation unit 136, the transverse plane position / attitude estimation unit 132, the self-position data generation unit 133, and the transverse plane measurement data acquisition unit 135 constitute a self-position estimation system 140 that generates self-position data related to the self-position of the unmanned aerial vehicle. In this embodiment, the flight control system is composed of the self-position estimation system 140, the flight path data storage unit 131, and the flight control unit 134. Fig. 5 is a diagram showing a hardware configuration of the information processing unit of the unmanned aerial vehicle shown in Fig. 1. Information processing unit 120 includes CPU 120a, RAM 120b, ROM 120c, external memory 120d, input unit 120e, output unit 120f, and communication unit 120g. RAM 120b, ROM 120c, external memory 120d, input unit 120e, output unit 120f, and communication unit 120g are connected to CPU 120a via bus 120h.

[0037] The CPU 120a comprehensively controls each device connected to the system bus 120h. The ROM 120c and the external memory store the BIOS and OS, which are control programs for the CPU 120a, as well as various programs and data required to realize the functions executed by the computer.

[0038] The RAM 120b functions as a main memory, a working area, etc. for the CPU 120a. The CPU 120a loads programs and the like required for executing processes from the ROM 120c or the external memory 120d into the RAM 120b, and executes the loaded programs to realize various operations. The external memory 120d is composed of, for example, a flash memory, a hard disk, a DVD-RAM, a USB memory, or the like.

[0039] The input unit 120e receives operation instructions, etc. from a user, etc. The input unit 120e is configured with input devices, such as, for example, an input button, a keyboard, a pointing device, a wireless remote control, a microphone, and a camera.

[0040] The output unit 120f outputs data processed by the CPU 120a and data stored in the RAM 120b, the ROM 120c, and the external memory 120d. The output unit 120f is composed of output devices such as a CRT display, an LCD, an organic EL panel, a printer, and a speaker.

[0041] The communication unit 120g is an interface for connecting and communicating with an external device directly or via a network, and is configured with an interface such as a serial interface or a LAN interface.

[0042] Each unit 121, 122, 125, 130 to 135 of the flight control system and the position estimation system shown in Figures 2 and 3 is realized by various programs stored in the ROM 120c and the external memory 120d using the CPU 120a, the RAM 120b, the ROM 120c, the external memory 120d, the input unit 120e, the output unit 120f, the communication unit 120g, etc. as resources.

[0043] The cross-sectional shape data storage unit 130 stores cross-sectional shape data relating to the cross-sectional shape of the inner wall surface of the tunnel. Furthermore, the flight route data storage unit 131 stores flight plan route data. The cross-sectional shape data storage unit 130 and the flight route data storage unit 131 are realized by reading data recorded in a storage medium and storing the data in a memory. Note that the cross-sectional shape data storage unit 130 and the flight route data storage unit 131 can also be omitted by incorporating the cross-sectional shape data and the flight plan route data into a program.

[0044] In this embodiment, the information processing unit 120 functions as a self-location estimation system and a flight control system, but these systems may be mounted separately from the information processing unit 120 and provided in the unmanned aerial vehicle. The self-location estimation system and the flight control system or components thereof do not need to be configured as one physical device, and may be configured as multiple physical devices. The self-location estimation system and the flight control system may be configured as any appropriate device such as a computer of a ground station separate from the unmanned aerial vehicle, a PC, a smartphone, a tablet terminal, a cloud computing system, or a combination thereof. The functions of each part of the self-location estimation system and the flight control system may be configured to be executed in a distributed manner in one or more of one or more devices provided in the unmanned aerial vehicle and one or more devices separate from the unmanned aerial vehicle.

[0045] 5A-5B show a tunnel and a flight plan route in one embodiment of the present invention, where 5A is a horizontal cross-sectional view of the tunnel, and 5B is a cross-sectional view taken along line BB in 5A. As shown in 5A-5B, in this embodiment, the cross section of inner wall surface 302 of tunnel 300 is circular, and extends vertically with the same cross-sectional shape. In addition, piping 310 extends vertically in the inner section of the tunnel, and the cross section of outer wall surface 312 of piping 310 is circular.

[0046] For this reason, the cross-sectional shape data showing the shape of the inner wall surface 302 of a known tunnel is recorded in an absolute coordinate system in which, for example, the center of the circular tunnel 300 is the origin (X=X0 (=0), Y=Y0 (=0)), the direction of the center of the pipe 310 relative to the center of the tunnel 300 is the Y-axis direction, and the height direction is the Z-axis direction. In such an absolute coordinate system, the cross-sectional shape data showing the inner wall surface 302 of the tunnel is expressed as (X-X0) 2 +(Y-Y0) 2 =R0 2The cross-sectional shape data showing the shape of the outer wall surface 312 of the pipe 310 of a known tunnel is expressed as (X-X1) where the center of the pipe 310 is X=X1 (=0), Y=Y1, the radius is R1, and the distance between the center of the tunnel 300 and the center of the pipe 310 is R2=Y1. 2 +(Y-R2) 2 =R1 2 In this embodiment, the cross-sectional shape data has the center of inner wall surface 302 of tunnel 300 as the origin, and the XY axes are set so that the center of pipe 310 is located on the Y axis, and includes radius R0 of the inner wall surface of tunnel 300, center coordinates of pipe 310, and radius R1 of pipe 310, but is not limited thereto, and it is sufficient if only the distance between inner wall surface 302 of tunnel 300 and the center of pipe 310 (R2 in the above example) is included.

[0047] In this embodiment, the cross-sectional shape data includes data indicating a circle as a geometric shape corresponding to the inner wall surface of the tunnel, but is not limited thereto, and may include data indicating a two-dimensional shape such as an ellipse or a rectangle according to the cross-sectional shape of the inner wall surface of the tunnel. Also, it may include data indicating an ellipse or a rectangle according to the cross-sectional shape of the outer wall surface of the pipe. The geometric shape referred to here refers to a shape that can be specified by a formula related to the X coordinate, the Y coordinate, and the Z coordinate, for example. Furthermore, the present invention is suitable for the cross-sectional shape data when the geometric shape is rotationally symmetric. The term "rotationally symmetric" refers to a state in which the cross-sectional shape of the inner wall surface is approximately equal to the original shape when it is rotated around a specific point, and includes an ellipse, a rectangle, a regular polygon, and the like.

[0048] The flight plan route data is data representing a three-dimensional (X, Y, Z) flight plan route in the absolute coordinate system of the unmanned aerial vehicle 1, and typically includes a series of multiple waypoints P1 to P2 existing on the flight plan route. mn The data for each waypoint P1~P mnare set in three-dimensional coordinates (X, Y, Z) in an absolute coordinate system. The flight plan route is typically a set of straight lines connecting the multiple waypoints in order, but may also be a curve with a predetermined curvature within a predetermined range of the waypoints. The flight plan route data may include data that determines the flight speed at the multiple waypoints. The flight plan route data is typically used to determine the flight plan route in an autonomous flight, but may also be used as a guide during flight in a non-autonomous flight. The flight plan route data is typically input to the unmanned aerial vehicle 1 before flight and stored. In this embodiment, the cross-sectional shape data and the flight plan route data are expressed in an XY coordinate system with the center of the tunnel 300 as the origin, but are not limited to this. For example, the cross-sectional shape data and the flight plan route data may be expressed in polar coordinates with the height Z and the center of the tunnel as the origin, based on the center direction of the piping relative to the center of the tunnel.

[0049] In this embodiment, as shown in FIG. 5B, the flight plan route is set as a repetition of the following meandering route. - Move a predetermined angle clockwise along the inner wall surface 302 of the tunnel 300 on a concentric circle in a transverse section (XY section) (for example, at waypoints P1 to P n ) - Move a given distance vertically (e.g., to waypoint P n ~P n+1 ) - Move a predetermined angle counterclockwise along the inner wall surface 302 of the tunnel 300 in a transverse section (XY section) on a concentric circle (for example, at waypoint P n+1 ~P 2n ) - Move a given distance vertically (e.g., to waypoint P 2n ~P 2n+1 )

[0050] The relative coordinate system calculation unit 136 calculates the relative coordinates of each characteristic point in the relative coordinate system based on the cross-section measurement data acquired by the cross-section measuring device 109 . The intra-transverse-plane position / attitude estimation unit 132 estimates the unmanned aerial vehicle's own position (X, Y) and heading θ within the transverse plane based on the relative coordinates calculated by the relative coordinate system calculation unit 136 and the cross-sectional shape data recorded in the cross-sectional shape data memory unit 130.

[0051] FIG. 6 is a horizontal cross-sectional view showing an area that can be measured by the cross-section measuring device. Point D in the figure indicates the position of the unmanned aerial vehicle 1. The cross-section measuring device 109 irradiates laser light at predetermined angles within the horizontal cross-section, based on a predetermined angle (forward of the unmanned aerial vehicle 1: in the direction of the arrow), receives the light reflected by the inner wall surface 302 of the tunnel 300 and the outer wall surface 312 of the pipe 310, and measures the distance to the target object (the inner wall surface 302 of the tunnel 300 and the outer wall surface 312 of the pipe 310) according to the time from irradiation to reception. Therefore, the cross-section measurement data obtained from the cross-section measuring device 109 is calculated based on the angle α at which the laser light is irradiated, based on the forward direction of the unmanned aerial vehicle 1 and the position of the unmanned aerial vehicle 1 as the origin. i and the distance to the object, r i The discrete data Q1 to Qn are in a relative coordinate system in which the discrete data Qi and the discrete data Qi are paired. The relative coordinates of each discrete data Qi are expressed as follows: i , r i ) (i = 1, . . . , n).

[0052] In this case, for example, when laser light is irradiated from the cross section measuring device 109 as shown in FIG. 6, the reflected light still reaches the cross section measuring device 109 at the portion A of the outer wall surface 312 of the pipe 310 facing the unmanned aerial vehicle 1, but most of the reflected light reflected at the portion B of the outer wall surface 312 of the pipe 310 on the side as seen from the unmanned aerial vehicle 1 does not head toward the cross section measuring device 109. Therefore, the cross section measuring device 109 cannot detect the portion B of the outer wall surface 312 of the pipe 310 on the side as seen from the unmanned aerial vehicle 1. In addition, the laser light does not reach the portion C located behind the pipe 310 on the inner wall surface 302 of the tunnel 300. Therefore, the cross section measuring device 109 cannot detect the portion C located behind the pipe 310 on the inner wall surface 302 of the tunnel 300.

[0053] The cross-section measurement data acquisition unit 135 can control the cross-section measuring device 109 and can acquire the cross-section measurement data measured by the cross-section measuring device 109 .

[0054] Taking this into consideration, in this embodiment, the unmanned aerial vehicle's own position in the transverse plane is estimated as follows. First, the relative coordinate system calculation unit 136 matches the first geometric shape, which is a circle in this embodiment, corresponding to the inner wall surface 302 of the tunnel 300 to the longitudinal cross-sectional data. Fig. 7 is a diagram showing how the optical transverse plane position estimation unit matches the circle corresponding to the inner wall surface of the tunnel to the longitudinal cross-sectional data. Note that Fig. 7 shows only a part of the data constituting the longitudinal cross-sectional data.

[0055] As shown in Fig. 7, the longitudinal section data consists of discrete points Q1 to Qn, and the relative coordinate system calculation unit 136 matches a circle to the discrete points Q1 to Qn. As an algorithm for circle matching, the least squares method, RANSAC, etc. can be used, but similar to line matching, RANSAC, which performs matching by removing outliers, is suitable. When matching a circle using RANSAC, the following procedure is performed. Step 1. First, randomly select three points from the discrete points Q1 to Qn. Step 2. Derive a temporary circle model passing through the three points determined in step 1. Step 3: Calculate the error between the obtained circular model and the discrete points Q1 to Qn. If the error is smaller than a predetermined value, add it to the "correct model candidates." Step 4. Repeat steps 1 to 3. Step 5. The correct model candidate that best matches the data is taken as the result of circle matching.

[0056] For example, in the example shown in FIG. 7, Q3 is far from the tendency of other discrete points among the discrete points corresponding to the inner wall surface of the tunnel. In the example shown in FIG. 7, if Q3, Q4, and Q5 are selected in step 1, the circle model becomes C1. In contrast, if Q1, Q4, and Q8 are selected in step 1, the circle model becomes C2. When the error between such circle models C1 and C and Q1 to Qn is calculated, the error of the circle model C1 is larger than the error of the circle model C2. For this reason, in step 5, values ​​that deviate from the tendency of other data such as Q3 used when setting the circle model C1 are not used as data for determining the circle, and a circle with the influence of the outlier removed such as the circle model C2 is matched. In this way, the first relative coordinate of the center point O1' as the first feature point of the circle model C2 based on the forward direction of the unmanned aerial vehicle 1 and the radius of the circle model C2 are estimated. The center point O1' as the first characteristic point of the circle model C2 corresponds to the center point of the inner wall surface 302 of the tunnel 300 in the absolute coordinate system.

[0057] In this embodiment, RANSAC is used as an algorithm for performing matching while excluding outliers, but it is also possible to use Markov Localization, Monte-Carlo Localization, Particle Filter, Hough Transform, etc.

[0058] Next, as shown in FIG. 8, the relative coordinate system calculation unit 136 compares the thus matched circle model C2 with the cross-section measurement data. In FIG. 8, the region in which the cross-section measurement data exists is indicated by a thick line. As described above, the laser light irradiated from the cross-section measurement device 109 does not reach the part of the inner wall surface 302 of the tunnel 300 that is behind the pipe 310. Therefore, by comparing the matched circle model C2 with the cross-section measurement data, it is possible to identify a gap region G in the circle model C2 in which no discrete data of the cross-section measurement data exists nearby. In addition, as a specific method of identifying the gap region G, for example, a method may be adopted in which the distance from the circle model C2 is within a predetermined range (i.e., the difference between the distance from the center point O1' to the discrete point and the radius of the circle model C2 is equal to or less than a predetermined value) between both end points of the discrete points of the cross-section measurement data. This gap region corresponds to an angle range in which the pipe 310 exists with the unmanned aerial vehicle 1 (cross-section measurement device 109) as the center. Then, a bisector L3 of the angle range centered on unmanned aerial vehicle 1 (cross section measurement device 109) of the gap region thus identified is identified. This bisector L3 indicates the direction of a point corresponding to the center of pipe 310 relative to unmanned aerial vehicle 1, based on the front of unmanned aerial vehicle 1. In other words, the direction of the center of pipe 310 in relative coordinates based on the front of unmanned aerial vehicle 1 can be estimated.

[0059] In this embodiment, since the pipe 310 is circular, the relative coordinate system calculation unit 136 sets the bisector of the gap region, but this is not limited to the above. If the shape of the pipe 310 is rectangular, the bisector may be corrected according to the shape. For example, if the shape of the pipe is rectangular, a straight line or the like may be matched to the part corresponding to the pipe in the cross-sectional measurement data, and the direction of the bisector may be corrected according to the angle of this straight line. The bisector when matching the circle and the bisector with the correction are called approximate bisectors. However, even if the shape of the pipe 310 is rectangular, it is not necessarily necessary to apply the correction, and the direction of the center can be estimated with high accuracy even if the bisector is used.

[0060] 9, the relative coordinate system calculation unit 136 identifies the relative coordinates of the intersection point O2' between the circle C3, in which the center of the piping 310 is located and the bisector L3, and the circle C3, which is centered on the center point O1' of the circle model C2. The position where the center of the piping 310 is located can be set as a circle of radius R2 centered on the center point O1 of the tunnel 300, based on the cross-sectional shape data. The relative coordinates of this intersection point O2' become the second position (relative coordinates) of the center point as a second characteristic point of the piping 310 relative to the unmanned aerial vehicle 1, with the forward direction of the unmanned aerial vehicle 1 as the reference point. Then, the relative coordinate system calculation unit 136 specifies the direction of the second relative coordinates of the intersection point O2' with respect to the first relative coordinates of the center point O1' of the circle model C2 specified as described above.

[0061] Next, the cross-sectional position / attitude estimation unit 132 performs coordinate conversion from the relative coordinate system to the absolute coordinate system so that the direction of the intersection point O2' with respect to the center point O1' in the relative coordinate system corresponds to the direction (Y-axis direction) of the center point O2 of the pipe 310 with respect to the center point O1 of the tunnel 300 in the absolute coordinate system, and the coordinate of the center point O1' in the relative coordinate system corresponds to the center point O1 of the tunnel 300 in the absolute coordinate system. Specifically, as shown in FIG. 10, the direction of the intersection point O2' with respect to the center point O1' of the circle model C2 specified as described above becomes the Y direction in the absolute coordinate system, and the relative coordinate system based on the unmanned aerial vehicle 1 is converted to the absolute coordinate system so that the center point O1' of the circle model C2 becomes the origin. This makes it possible to calculate the X coordinate, Y coordinate, and heading θ of the unmanned aerial vehicle 1.

[0062] The method of identifying the second positional relationship between the self-position of unmanned aerial vehicle 1 and pipe 310 is not limited to the method of identifying the gap region described above. That is, for example, a circle, which is a second predetermined shape, may be matched to the cross-sectional measurement data of the inner region of circle model C2 (particularly the region indicated by A in FIG. 6), and the relative coordinates of the center point, which is a predetermined point of the matched circle, may be estimated as the relative coordinates corresponding to the center of pipe 310, or both methods may be performed to improve accuracy.

[0063] The self-position data generating unit 133 generates self-position data that serves as a reference when the flight control unit 134 flies. Specifically, the self-position data generating unit 133 generates self-position data including XYZ coordinates and heading θ based on the X coordinate, Y coordinate, and heading θ estimated by the intra-transverse-plane position / attitude estimating unit 132 and the altitude (Z coordinate) acquired from the altimeter 110.

[0064] The flight control unit 134 controls the flight of the unmanned aerial vehicle to follow the flight plan route of the flight plan route data stored in the flight route data storage unit 131 based on the self-position data generated by the self-position data generation unit 133. Specifically, the flight control unit 134 determines the attitude, speed, etc. of the unmanned aerial vehicle 1 using various sensors, determines the current flight position and heading of the unmanned aerial vehicle 1 based on the self-position data generated by the self-position data generation unit 133, calculates a control command value for each rotor 103 by comparing it with target values ​​such as a control signal, a flight plan route (target), a speed limit, and an altitude limit, and outputs data indicating the control command value to the control signal generation unit 122. The control signal generation unit 122 converts the control command value into a pulse signal representing a voltage and transmits it to each speed controller 123. Each speed controller 123 converts the pulse signal into a drive voltage and applies it to each motor 102, thereby controlling the drive of each motor 102 to control the rotation speed of each rotor 103, thereby controlling the flight of the unmanned aerial vehicle 1.

[0065] The flow of how the unmanned aerial vehicle described above autonomously flies inside a tunnel and photographs the inner wall surface of the tunnel will be described below. Fig. 11 is a flow chart showing a flow of autonomously flying inside a tunnel and photographing the inner wall surface of the tunnel by the unmanned aerial vehicle shown in Fig. 1. As shown in Fig. 11, first, the information processing unit 120 refers to the flight plan route data stored in the flight route data storage unit 131, and the flight control unit 134 sets the first waypoint as a target (S100).

[0066] Next, the information processing unit 120 estimates the self-position and attitude of the unmanned aerial vehicle 1 using the self-position data generation unit 133, and the flight control unit 134 controls the rotation speed of the motor 102 based on the estimated self-position and attitude, thereby performing autonomous flight toward the target (S110).

[0067] Fig. 12 is a detailed flow chart showing a flow of autonomous flight by the unmanned aerial vehicle shown in Fig. 1. When estimating the self-position, first, the cross-section measurement data acquisition unit 135 controls the cross-section measuring device 109 to measure the cross-section measurement data, and then controls the cross-section measuring device 109 to acquire the cross-section measurement data (S111: cross-section measurement data acquisition step). Then, the relative coordinate system calculation unit 136 and the transverse plane position / attitude estimation unit 132 estimate the unmanned aerial vehicle's own position (X, Y) and attitude (heading θ) in the longitudinal section within the transverse plane based on the longitudinal section measurement data acquired by the transverse section measuring device 109 and the cross-sectional shape data recorded in the cross-sectional shape data memory unit 130.

[0068] Specifically, first, as described with reference to Figure 7, the relative coordinate system calculation unit 136 matches the horizontal cross-sectional data with a circle corresponding to the inner wall surface 302 of the tunnel 300, and identifies the first relative coordinate of the center position (corresponding to the center coordinate of the tunnel inner wall surface 302) as the first feature point of the circle based on the position and attitude of the unmanned aerial vehicle 1 (S112: first feature point estimation step).

[0069] Next, as described with reference to Figure 8, the relative coordinate system calculation unit 136 identifies a gap region G in the horizontal cross-sectional data that is located behind the pipe 310 in the circular model C2, does not reach the laser light, and corresponds to an angular range in which no discrete data of the cross-sectional measurement data exists in the vicinity (S113).

[0070] Next, as described with reference to Figure 9, the relative coordinate system calculation unit 136 sets a bisector L3 of the angular range of the gap region G centered on the unmanned aerial vehicle 1 (cross section measuring device 109) (S114).

[0071] Next, the relative coordinate system calculation unit 136 acquires the distance between the center of the tunnel 300 and the center of the piping 310 based on the cross-sectional shape data, and sets a circle centered on the center point of the matched circle and with a radius equal to the distance between the center of the tunnel 300 and the center of the piping 310. Then, the relative coordinates of the intersection of this circle and the bisector are calculated, and the calculated relative coordinates are set as the second relative coordinates of the second feature point corresponding to the center of the piping 310 (S115: second feature point estimation step).

[0072] Next, the relative coordinate system calculation unit 136 calculates the direction of the center point O2 of the pipe 310 corresponding to the center of the pipe 310 with respect to the first relative coordinate of the center point O' of the circle in the relative coordinate system (S116: calculation step). Then, transverse plane position / attitude estimation unit 132 performs coordinate conversion so that the direction of intersection point O2' relative to center point O1' in the relative coordinate system corresponds to the direction (Y-axis direction) of center point O2 of pipe 310 relative to center point O1 of tunnel 300 in the absolute coordinate system, and the coordinates of center point O1' in the relative coordinate system correspond to center point O1 of tunnel 300 in the absolute coordinate system. This allows the absolute coordinates of the unmanned aerial vehicle 1's own position in the transverse plane and the heading θ to be estimated (S117: transverse plane position / attitude estimation step).

[0073] Next, the self-position data generating unit 133 generates self-position data from the lateral self-position (X, Y) and heading θ estimated by the transverse plane position / attitude estimating unit 132 and the altitude (Z) measured by the altimeter 110 (S118: self-position data generating step). Note that the self-position data generating unit 133 determines the accuracy of the generated self-position data based on the position information acquired from the IMU 111, and may stop shooting inside the tunnel if the accuracy of the generated self-position data is low.

[0074] Then, the flight control unit 134 determines whether the unmanned aerial vehicle 1 has reached the target based on the self-position data generated by the self-position data generation unit 133 (S119).

[0075] If the flight control unit 134 determines that the unmanned aerial vehicle 1 has not reached the target (NO in S119), the flight control unit 134 calculates a control command value for each rotor 103 so as to fly toward the target based on the self-position data generated by the self-position data generation unit 133, and outputs data indicating the control command value to the control signal generation unit 122 (S120). The control signal generation unit 122 converts the control command value into a pulse signal representing a voltage and transmits it to each speed controller 123. Each speed controller 123 converts the pulse signal into a drive voltage and applies it to each motor 102, thereby controlling the drive of each motor 102 to control the rotation speed of each rotor 103, thereby controlling the flight of the unmanned aerial vehicle 1.

[0076] By repeating S111 to S120 at a predetermined short time interval, unmanned aerial vehicle 1 autonomously flies toward the target. In this way, unmanned aerial vehicle 1 reaches the target, and when flight control unit 134 determines in S119 that unmanned aerial vehicle 1 has reached the target (YES in S119), information processing unit 120 drives camera 108 to capture an image of the inner wall surface of the tunnel (S130). Image data of the captured image is stored in the memory of information processing unit 120, or recorded in an appropriate terminal via antenna 117.

[0077] And the target reached by unmanned aerial vehicle 1 is the final waypoint P mn If not (NO in S140), the next waypoint P is set as the target (S135), and S110 to S140 are repeated.

[0078] Well, the target that unmanned aerial vehicle 1 reached is the final waypoint P mn If this is the case (YES in S135), the unmanned aerial vehicle 1 determines that all necessary steps have been completed, and ends the operation by, for example, flying to return to the initial position, via the flight control unit 134.

[0079] According to this embodiment, the following effects are achieved. In the tunnel, GPS and the like cannot be used, and furthermore, a compass cannot be used due to the influence of geomagnetism. In such a case, when estimating the self-position of the unmanned aerial vehicle, it is possible to estimate the position using an algorithm such as laser SLAM. However, even if an attempt is made to estimate the position using an algorithm such as laser SLAM, if the cross-sectional shape of a tunnel or the like is rotationally symmetric, it is difficult to estimate the accurate position. In contrast, in this embodiment, the relative coordinate system calculation unit 136 calculates the direction between point O1' corresponding to the center of the tunnel 300 in the relative coordinate system and point O2' corresponding to the center of the pipe 310, and based on this direction, the relationship between the relative coordinate system and the absolute coordinate system can be specified, and the self-position can be accurately estimated even inside the tunnel 300, which has a rotationally symmetric shape. In addition, in this embodiment, the relative coordinate system calculation unit 136 matches a circle to the inner wall surface of the tunnel. The inner wall surface of a tunnel is often a circle, an ellipse, or a rectangle, but even if a rotationally symmetric shape such as a circle, an ellipse, or a rectangle is matched, the position of the unmanned aerial vehicle cannot be uniquely identified only from the positional relationship between the circle, ellipse, or rectangle and the unmanned aerial vehicle. In contrast, in this embodiment, a point corresponding to the center of the pipe 310 in the cross-sectional measurement data is identified, so that the position of the unmanned aerial vehicle can be uniquely identified.

[0080] In this embodiment, the cross-sectional position / attitude estimation unit 132 performs coordinate conversion so that the direction of point O2' corresponding to the center of the pipe 310 relative to point O1' corresponding to the center of the tunnel 300 in the relative coordinate system corresponds to the Y axis, which is the reference axis. This makes it possible to estimate the heading direction of the unmanned aerial vehicle in the absolute coordinate system. In this embodiment, the cross-sectional position / attitude estimation unit 132 performs coordinate conversion so that the direction of point O2' corresponding to the center of the pipe 310 relative to point O1' corresponding to the center of the tunnel 300 in the relative coordinate system corresponds to the Y axis, which is the reference axis, and further, point O1' in the relative coordinate system corresponds to the origin corresponding to the center of the tunnel in the absolute coordinate system. This makes it possible to estimate the coordinates of the unmanned aerial vehicle in the absolute coordinate system.

[0081] In addition, in this embodiment, the relative coordinate system calculation unit 136 identifies a gap region G where no data exists within a range corresponding to the circle in the cross-section measurement data, and estimates a point corresponding to the center point of the pipe 310 in the relative coordinate system by determining the intersection between the bisector of the gap region G and a circle of radius R2 centered on the center point O1' of the matched circle C2. This makes it possible to estimate the position of the unmanned aerial vehicle 1, for example, even if the radius of the pipe 310, etc., is unknown. Also, for example, as in this embodiment, even if the cross-sectional shape of the pipe 310 is circular and the side surface of the pipe 310 cannot be measured by the cross-section measurement device 109 when viewed from the unmanned aerial vehicle 1, the relative coordinates of the pipe 310 can be accurately estimated.

[0082] In this embodiment, the cross-section measurement data is discrete data, and the relative coordinate system calculation unit 136 removes outliers in the discrete data before performing matching. This makes it possible to perform matching even if the inner wall surface 302 of the tunnel 300 has irregularities due to lighting or has ventilation openings formed therein.

[0083] In this embodiment, a case has been described in which circular pipe 310 extends vertically, but the cross-sectional shape of pipe 310 (internal structure) is not limited to this and may be other shapes such as rectangular. When the cross-sectional shape of the internal structure is rectangular, when the bisector of the gap region is set in S113, the bisector does not necessarily pass through the center of the rectangle, but the error is small and does not cause any practical problem.

[0084] In this embodiment, the relative coordinate system calculation unit 136 matches a circle to the cross-sectional measurement data in S112, then identifies the gap region in S113, sets the bisector of the angle range of the gap region in S114, and identifies the intersection between the bisector of the gap and the circle on which the center of the pipe is located in S115, thereby calculating the relative coordinates of the pipe 310. However, the calculation method of the relative coordinate system calculation unit 136 of the present invention is not limited to this. For example, when the shape of the cross section of the pipe 310 is circular, for example, it is possible to match a circle, which is a second predetermined shape, to the data outside the range of the inner wall surface 302 of the tunnel 300 in the cross-sectional measurement data, to identify a predetermined position (for example, a center position) of the pipe 310, and set this position as the position of the second feature point related to the pipe 310 in the relative coordinate system. Naturally, when the shape of the pipe 310 is elliptical or rectangular, the second predetermined shape to be matched may be changed accordingly. It is noted that the matching second predetermined shape is preferably a geometric shape.

[0085] Furthermore, in this embodiment, the height coordinate is determined by the altimeter, but this is not limiting, and the height coordinate may be determined by an IMU.

[0086] In this embodiment, the present invention is applied to the tunnel 300 extending in the vertical direction, but it is not limited to this and can be applied to a chimney, a shaft inside a building, etc. Furthermore, the present invention can be applied to a tunnel extending diagonally upward, etc. In this case, it is only necessary to store the cross-sectional shape data of the tunnel 300 and the internal structure for each height in the cross-sectional shape data storage unit 130. [Explanation of symbols]

[0087] 1 unmanned aerial vehicle 101 Control unit 102 Motor 103 Rotor 104 Arm 105 Landing leg 106 Pedestal 107 Support member 108 Camera 110 Altimeter 109 Cross-section measuring device 111 IMU 117 Antenna 120 Information Processing Unit 120a CPU 120b RAM 120c ROM 120d External Memory 120e Input section 120f Output section 120g Communication section 120h system bus 121 Communication Circuit 122 Control signal generator 123 Speed ​​Controller 125 Interface 130 Cross-sectional shape data storage unit 131 Flight route data storage unit 132 Transverse plane position / posture estimation unit 133 Self-location data generation unit 134 Flight Control Unit 135 Cross-sectional measurement data acquisition section 136 Relative Coordinate System Calculation Unit 140 Self-location estimation system 200 Flight Control System 300 Tunnels 302 Inner wall surface 310 Piping 312 Exterior wall surface

Claims

1. An estimation system for estimating a self-position and / or attitude of an unmanned aerial vehicle, comprising: The unmanned aerial vehicle includes a cross section measurement device that measures a spatial shape of the unmanned aerial vehicle relative to a predetermined direction of the unmanned aerial vehicle in a cross section in a direction intersecting a longitudinal flight path of the unmanned aerial vehicle and generates cross section measurement data; a cross section measurement data acquisition unit that acquires the cross section measurement data generated by the cross section measurement device when the unmanned aerial vehicle flies through an interior space of a structure in which an interior space extending vertically along a predetermined path is formed and an internal structure extending vertically is provided within the interior space; A rotationally symmetric first predetermined shape corresponding to a cross-sectional shape of an inner wall surface of the structure is matched to the cross-sectional measurement data acquired by the cross-sectional measurement data acquisition unit, and a first position of a first feature point that is a center of the matched first predetermined shape in a relative coordinate system based on the unmanned aerial vehicle in the cross-section is estimated; estimating a second position of a second feature point associated with the internal structure in the relative coordinate system based on the cross-sectional measurement data acquired by the cross-sectional measurement data acquisition unit; a relative coordinate system calculation unit that calculates a direction of the second position relative to the first position in the relative coordinate system; Equipped with Estimation system.

2. An estimation unit is further provided that estimates a self-position and / or attitude of the unmanned aerial vehicle in an absolute coordinate system having a reference axis in a direction of a point corresponding to a second characteristic point of the internal structure relative to a point corresponding to a first characteristic point of the structure on the cross section. The estimation system according to claim 1 .

3. The estimation unit is a coordinate transformation of the relative coordinate system into an absolute coordinate system so that a direction of the second position relative to the first position in the relative coordinate system corresponds to the reference axis, and a heading direction of the unmanned aerial vehicle in the absolute coordinate system is estimated; The estimation system according to claim 2 .

4. The estimation unit is performing coordinate transformation so that a direction of the second position relative to the first position in the relative coordinate system corresponds to the reference axis and the first position in the relative coordinate system corresponds to a coordinate in an absolute coordinate system corresponding to the first feature point of the structure, thereby estimating a coordinate in the absolute coordinate system of the unmanned aerial vehicle; The estimation system according to claim 2 or 3.

5. The first predetermined shape is a circle, an ellipse, or a rectangle. The estimation system according to any one of claims 1 to 4.

6. The relative coordinate system calculation unit identifying gap areas in the cross-sectional measurement data within an area adjacent the matched first predetermined shape where no data is present; an intersection point between an approximate bisector of an angular range of the gap region relative to the unmanned aerial vehicle and a circle having a radius equal to a distance between the preset first feature point and the preset second feature point and centered on the first feature point is estimated as the second position; The estimation system according to any one of claims 1 to 5.

7. The relative coordinate system calculation unit A second predetermined shape corresponding to a portion corresponding to the internal structure is matched to the cross-sectional measurement data, and relative coordinates of a predetermined point on the matched second predetermined shape are estimated as the second position. The estimation system according to any one of claims 1 to 5.

8. the cross-sectional measurement data is discrete data; the relative coordinate system calculation unit removes outliers in the discrete data and performs matching. The estimation system according to any one of claims 1 to 7.

9. The estimation system according to any one of claims 1 to 8, A flight control unit that flies the unmanned aircraft along a set flight plan route based on the self-position and / or attitude of the unmanned aircraft estimated by the estimation system. Unmanned aerial vehicle flight control system.

10. An unmanned aerial vehicle comprising an estimation system according to any one of claims 1 to 8.

11. An unmanned aerial vehicle comprising the flight control system of claim 9.

12. A method for estimating a self-position and / or attitude of an unmanned aerial vehicle by a computer, comprising: The unmanned aerial vehicle includes a cross section measurement device that measures a spatial shape of the unmanned aerial vehicle relative to a predetermined direction of the unmanned aerial vehicle in a cross section in a direction intersecting a longitudinal flight path of the unmanned aerial vehicle and generates cross section measurement data; a cross-section measurement data acquisition step of acquiring the cross-section measurement data generated by the cross-section measurement device when the unmanned aerial vehicle flies through an interior space of a structure in which an interior space extending vertically along a predetermined path is formed and an internal structure extending vertically within the interior space is provided; a first feature point estimation step of matching a rotationally symmetric first predetermined shape corresponding to a cross-sectional shape of an inner wall surface of the structure to the acquired cross-section measurement data, and estimating a first position of a first feature point that is the center of the matched first predetermined shape in a relative coordinate system based on the unmanned aerial vehicle in the cross-section; a second feature point estimating step of estimating a second position of a second feature point associated with the internal structure in the relative coordinate system based on the acquired cross-sectional measurement data; a calculation step of calculating an orientation of the second position relative to the first position in the relative coordinate system; A self-location estimation method comprising:

13. A program for causing a computer to execute the method according to claim 12.

14. A computer-readable recording medium having the program according to claim 13 recorded thereon.

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