JP6699019B2 - Wall measuring device, flying robot and wall inspection system - Google Patents

Description

  The present invention relates to a wall surface measuring device that measures a distance and an inclination of a wall surface by using a laser beam, a flying robot equipped with the wall surface measuring device, and a wall surface inspection system using the flying robot.

  Structures such as piers will deteriorate over time. Therefore, in this type of structure, the condition of the wall surface is regularly inspected, and appropriate measures such as restoration are taken. In this case, for example, the condition of the wall surface is inspected using a camera. By analyzing the image captured by the camera, for example, cracks formed on the surface of the pier or the like are confirmed.

  The following Patent Document 1 describes a wall surface detection unit that measures the distance and the inclination of the wall surface using laser light. In the configuration of Patent Document 1, a laser scanner mounted on an automobile scans a laser beam in a horizontal direction and a vertical direction to acquire data of a three-dimensional coordinate point group. On the basis of the coordinate point cloud data acquired in this way, the wall surface of an accessory of the road, the wall surface of the building near the road, the wall, etc. is detected.

JP, 2013-54522, A

  Structures such as piers are often very tall. Further, when the pier is a pier of a bridge spanning a river, it may be extremely difficult for an operator who performs inspection to approach the vicinity of the pier. In such a case, it is effective to mount a camera on a flying robot that can be stopped in the air and image the surface of the structure.

  When mounting a camera on a flying robot, it is necessary to control the attitude of the flying robot so that the imaging direction of the camera is substantially perpendicular to the wall surface of the structure. For this control, the flying robot can be equipped with a wall surface measuring device that measures the distance to the wall surface and the inclination of the structure. In this case, in order to reduce the load on the flying robot, it is preferable that the mounted wall surface measuring device has a mass as small as possible. On the other hand, a laser scanner mounted on an automobile is usually provided with two actuators for individually scanning the laser beam in the horizontal direction and the vertical direction, respectively, so that the mass of the wall surface measuring device becomes large.

  The present invention has been made in view of the above problems, and provides a wall surface measuring device capable of reducing the mass as much as possible, a flight robot equipped with the wall surface measuring device, and a wall surface inspection system using the flight robot. The purpose is to do.

A first aspect of the present invention relates to a wall surface measuring device. A wall surface measuring device according to this aspect includes a light source that emits a laser beam, a photodetector that receives the laser beam reflected from an object, and the light source and the photodetector that are integrally rotated around one axis. A rotating unit, a supporting member that supports the rotating unit, a mirror that is installed on the supporting member, and that reflects the laser light emitted from the light source in a partial rotation range of the rotating unit; And a calculation processing unit that calculates a distance to the wall surface and an inclination of the wall surface of the object at the position irradiated with the laser light based on a signal output from the container. The mirror is configured so that the object is scanned in a plurality of different scanning paths as the rotating unit rotates. Further, the arithmetic processing unit acquires, as a wall surface of the object, a plane that matches a three-dimensional coordinate point group obtained by measuring distances to the object along the plurality of scanning paths.

  According to the wall surface measuring apparatus of this aspect, only a rotating unit that rotates about one axis and a mirror that reflects the laser light need to be provided as a configuration for scanning the laser light. Therefore, the mass of the wall surface measuring device can be significantly reduced as compared with the case where two actuators for individually scanning the laser light in the horizontal direction and the vertical direction are provided. Therefore, when the wall surface measuring device is mounted on the flying robot, the load on the flying robot can be effectively suppressed. Furthermore, since the rotating unit and the mirror are arranged, the wall surface measuring device can be simplified and downsized. Therefore, also from this point, the wall surface measuring device according to this aspect is advantageous when mounted on a flying robot.

  In the wall surface measuring device according to the first aspect, the three mirrors are arranged so as to surround the rotating portion, and the optical axes of the laser beams emitted from the light source are bent by the three mirrors, whereby the respective mirrors are bent. Can be configured to be scanned in three scanning paths corresponding to By scanning the object through the three scanning paths in this manner, the wall surface of the object can be accurately measured.

  In the wall surface measuring device according to the first aspect, the two mirrors are arranged so as to sandwich the rotating portion, and the optical axis of the laser light emitted from the light source is bent by the two mirrors. The object may be configured to be scanned in multiple scan paths, including two scan paths corresponding to each mirror. With this configuration, as compared with the case where three mirrors are used as described above, one mirror can be reduced and the mass of the wall surface measuring device can be suppressed.

  In this case, the wall surface measuring device has a scanning path generated when the laser light passes through the gap between the two mirrors and two scanning paths generated when the laser light is reflected by the two mirrors. , The two mirrors may be arranged so that the object is scanned. By doing so, the object is scanned through the three scanning paths, so that the wall surface of the object can be accurately measured.

  Further, the wall surface measuring apparatus according to the first aspect is configured such that one of the mirrors is arranged around the rotating portion, and the scanning path is generated when the laser light passes through a region where the mirror is not arranged, The mirror may be arranged so that the object is scanned in a scanning path generated by the laser beam being reflected by the mirror. With this configuration, since only one mirror is used for scanning, the mass of the wall surface measuring device can be further suppressed.

  In the wall surface measuring device according to the first aspect, the plurality of scanning paths may be set so as to substantially follow each side of the triangle in a plane that directly faces the wall surface measuring device. In this way, the wall surface obtained by the measurement is less likely to cause an error in inclination in any direction term with respect to the regular wall surface. Therefore, the measurement accuracy of the wall surface can be improved.

  Further, in the wall surface measuring apparatus according to the first aspect, the reflecting surface of the mirror has a flat surface and a shape that is long in one direction, and the optical axis of the laser light is the reflecting surface as the rotating portion rotates. The mirror may be arranged so as to move in the longitudinal direction. By doing so, the scanning locus of the object can be set in three directions while using a mirror having a simple structure. Therefore, the measurement accuracy of the object wall surface can be improved.

  In the wall surface measuring device according to the first aspect, the arithmetic processing unit changes the distance to the plane and the inclination of the plane to count the number of the coordinate point groups included in the plane, and the counted number is the largest. It may be configured to capture a plane as the wall surface of the object. By doing so, the wall surface of the object can be smoothly acquired from the coordinate point group.

  A second aspect of the present invention relates to a flying robot. A flight robot according to this aspect is based on the wall surface measuring device according to the first embodiment, an imaging device that images the wall surface, a propeller drive unit for flying in a stationary manner, and a measurement result by the wall surface measuring device. And a control unit for controlling the flight attitude.

  According to the flying robot of this aspect, since the wall surface measuring device whose mass is suppressed as described above is mounted, the load during flight is reduced. Therefore, it is possible to smoothly and stably fly to the target wall surface position and image the wall surface.

  A third aspect of the present invention relates to a wall surface inspection system. A wall surface inspection system according to this aspect includes the flying robot according to the second aspect, and an information processing device that processes an image captured by the image capturing device to evaluate the situation of the wall surface.

  According to the wall surface inspection system of this aspect, since the above flying robot is used, the wall surface can be smoothly and stably imaged, and the wall surface can be smoothly inspected.

  As described above, according to the present invention, it is possible to provide a wall surface measuring device capable of reducing the mass as much as possible, a flight robot equipped with the wall surface measuring device, and a wall surface inspection system using the flight robot.

  The features of the present invention will be further clarified by the following description of the embodiments. However, the following embodiment is just one embodiment of the present invention, and the meanings of the terms of the present invention and each constituent element are not limited to those described in the following embodiment. Absent.

FIG. 1 is a perspective view showing the appearance of a wall surface inspection system according to an embodiment. 2A and 2B are a plan view and a side view, respectively, showing the configuration of the scanning detection unit according to the embodiment. FIG. 2C is a diagram showing the configuration of the optical system held by the rotating unit according to the embodiment. FIG. 2D is a timing chart illustrating a method of measuring the distance to the object. FIG. 3A is a diagram schematically showing a scanning path according to the embodiment, and FIG. 3B is a diagram for explaining a wall surface detection method according to the embodiment. FIG. 4 is a block diagram showing the configuration of the flying robot according to the embodiment. FIG. 5A is a flowchart showing the process of the wall surface measuring device according to the embodiment. FIG. 5B is a flowchart showing the wall surface measuring process according to the embodiment. 6A and 6B are a plan view and a side view, respectively, showing the configuration of the scanning detection unit according to the first modification. FIG. 6C is a diagram schematically showing the scanning path according to the first modification. 7A and 7B are a plan view and a side view, respectively, showing the configuration of the scanning detection unit according to the second modification. FIG. 7C is a diagram schematically showing the scanning path according to the second modification. 8A and 8B are a plan view and a side view, respectively, showing the configuration of the scanning detection unit according to the third modification. FIG. 8C is a diagram schematically showing the scanning path according to the third modification.

  FIG. 1 is a perspective view showing an appearance of a wall surface inspection system 1 according to an embodiment. In FIG. 1, for convenience, the front-back direction, the left-right direction, and the up-down direction of the flying robot 10 are indicated by solid arrows.

  As shown in FIG. 1, the wall surface inspection system 1 includes a flying robot 10 and an information processing device 20.

  The flying robot 10 includes six propellers 11. The flying robot 10 is capable of driving the propeller 11 to fly, and controlling the propeller 11 to stand still in the air in a predetermined posture. The flying robot 10 includes a pair of legs 12 for landing.

  Furthermore, the flying robot 10 includes a cylindrical shaft 13 that linearly extends in the front direction. A pulley 14 is rotatably attached to the tip of the shaft 13. The rotation axis of the pulley 14 is parallel to the left-right direction. An encoder (not shown) for detecting the rotation of the pulley 14 is arranged on the rotary shaft of the pulley 14. The encoder is connected to the circuit section of the main body of the flying robot 10 by wiring passing through the inside of the shaft 13.

  When inspecting the wall surface 2 such as a bridge pier, the flying robot 10 moves in the vertical direction with the pulley 14 in contact with the wall surface 2. The flying robot 10 acquires the position of the wall surface 2 in the vertical direction based on the signal output from the encoder during this movement. The vertical position may be detected by a configuration other than the configuration using the pulley 14 and the encoder. For example, the flying robot 10 can be provided with a GPS (Global Positioning System) function. However, on the pier, the GPS function may be disabled due to the obstruction by the bridge. Further, there is a predetermined error in the positioning by GPS. From this, it is preferable that the position of the wall surface 2 in the vertical direction be directly obtained from the wall surface 2 by the configuration shown in FIG. The flying robot 10 may further include a sensor for altitude detection, such as an atmospheric pressure sensor or a gyro sensor. The flying robot 10 may be configured to acquire the position of the wall surface 2 in the height direction by this sensor.

  A shelf 15 is provided on the lower surface of the flying robot 10. A wall surface measuring device 30, an imaging device 40, and a memory drive 50 are installed on this shelf 15. The wall surface measuring device 30 and the memory drive 50 are installed on the upper surface of the shelf 15, and the imaging device 40 is installed on the lower surface of the shelf 15.

  The wall surface measuring device 30 emits laser light in the forward direction, receives reflected light from the wall surface 2, and calculates the distance to the wall surface 2 and the inclination of the wall surface 2. The configuration of the wall surface measuring device 30 and the wall surface measuring method will be described later with reference to FIGS. 2(a) to 3(b).

  The imaging device 40 images the area in front of the flying robot 10. The imaging direction of the imaging device 40 matches the front direction of the flying robot 10. The memory drive 50 is arranged behind the wall surface measuring device 30. A storage medium such as an SD card can be attached to and detached from the memory drive 50. The memory drive 50 writes the image picked up by the image pickup device 40 into the storage medium as needed.

  Based on the distance to the wall surface 2 and the inclination of the wall surface calculated by the wall surface measuring device 30, the flying robot 10 sets the imaging direction of the imaging device 40 to be substantially perpendicular to the wall surface 2, and the pulley 14 on the wall surface 2. Controls its own position and attitude to make contact. While performing this control, the flying robot 10 moves in the circumferential direction along the wall surface 2. Meanwhile, the imaging device 40 images the wall surface 2. The captured images are sequentially written in the storage medium of the memory drive 50.

  The flight path of the flying robot 10 is set by the user via the information processing device 20. The information processing device 20 is connected to the remote control device 60 by a cable. The information processing device 20 transmits a command signal for causing the flying robot 10 to fly along the flight route set by the user to the flying robot 10 via the remote control device 60.

  The automatic position control function of the flying robot 10 is mainly executed by a control unit 84 (see FIG. 4) of the flying robot 10 described later. The information processing device 20 transmits a command signal for instructing a next target position to be a flight path and a flight operation to the control unit 84 of the flying robot 10 via the remote control device 30. For example, the remote control device 30 transmits a command signal to the flying robot 10 to drop a few meters along the wall surface 2 while keeping the distance from the wall surface 2 at a constant distance. Based on this command signal, the control unit 84 of the flying robot 10 controls the propeller 11 to execute a flight operation according to the command. As a result, the flying robot 10 flies near the wall surface 2 along the set flight path.

  The flying robot 10 thus flies along the flight path set by the user, and based on the distance to the wall surface 2 and the inclination of the wall surface 2 calculated by the wall surface measuring device 30, as described above, Control your posture.

  While the flying robot 10 is flying, position information of the flying robot 10 detected by the pulley 14 and the encoder is transmitted from the flying robot 10 to the remote control device 60 at any time and provided to the information processing device 20. The information processing device 20 controls the flying robot 10 to fly along a desired flight path based on the received position information. In this way, the flying robot 10 flies along the flight path set by the user.

  Alternatively, the user may operate the remote control device 60 to manually fly the flying robot 10 near the wall surface 2. In this case, the image acquired by the imaging device 40 is transmitted to the remote control device 60 at any time and displayed on the monitor 61 of the remote control device 60. The user operates the remote control device 60 while referring to the monitor 61 to move the flying robot 10 along the wall surface 2. Also in this case, the flying robot 10 makes the imaging direction of the imaging device 40 substantially perpendicular to the wall surface 2 based on the distance to the wall surface 2 calculated by the wall surface measuring device 30 and the inclination of the wall surface 2, and also the pulley. The position and the posture of itself are controlled so that 14 contacts the wall surface 2.

  When the inspection of the wall surface 2 is completed, the user collects the flying robot 10 and takes out the storage medium from the memory drive 50. The user mounts the removed storage medium on the information processing device 20. The information processing device 20 is composed of, for example, a personal computer. The information processing device 20 reads the image information from the storage medium according to the operation of the user, analyzes the read image information, and evaluates the situation of the wall surface 2. The information processing device 20 displays the evaluation result on the screen. For example, when a crack or the like is found on the wall surface 2 by the analysis process, the information processing device 20 displays a screen notifying the user of that.

  2A and 2B are a plan view and a side view, respectively, showing the configuration of the scanning detection unit 31 arranged in the wall surface measuring device 30. 2A and 2B show the front-back, left-right, and up-down directions of the flying robot 10 shown in FIG. 2A and 2B, the arithmetic processing unit 32 is shown together with the scanning detection unit 31. The arithmetic processing unit 32 calculates the distance to the wall surface 2 and the inclination of the wall surface 2 based on the signal output from the scan detection unit 31.

  As shown in FIGS. 2A and 2B, the scanning detection unit 31 includes three mirrors 311, 312, 313 and a rotating unit 314. The three mirrors 311, 312, 313 and the rotating portion 314 are installed on the support member 315. The three mirrors 311, 312, 313 are arranged along each side of a predetermined triangle so as to surround the rotating portion 314. The mirrors 311, 312, 313 each have a plate-like rectangular parallelepiped shape, and have reflecting surfaces 311a, 312a, 313a on the rotating unit 314 side. The reflection surfaces 311a, 312a, 313a are flat surfaces, respectively. The mirrors 311, 312, 313 are formed, for example, by forming reflecting surfaces 311a, 312a, 313a on the side surface of the main body made of a lightweight material such as resin by coating or vapor deposition.

  The mirror 311 is arranged so that the longitudinal direction of the reflecting surface 311a is parallel to the left-right direction in a plan view. The mirror 312 is arranged such that the longitudinal direction of the reflecting surface 312a is inclined rightward by a predetermined angle with respect to the vertical direction in a plan view. The mirror 313 is arranged such that, in a plan view, the longitudinal direction of the reflecting surface 313a is inclined leftward by a predetermined angle with respect to the vertical direction. The mirrors 312 and 313 are arranged at positions symmetrical with respect to an axis of symmetry that is parallel to the vertical direction in a plan view, and the axis of rotation of the rotating unit 314 perpendicularly intersects the axis of symmetry. Further, the mirror 311 is arranged so as to be divided into two equal parts by the symmetry axis in a plan view.

  The arrangement method of the mirrors 311, 312, 313 is not limited to this. As will be described later, if the three scanning paths of the laser light on the wall surface 2 are set so as to substantially follow each side of the triangle, the mirrors 311, 312, 313 may be arranged by another arrangement method.

  The rotating unit 314 rotates about an axis parallel to the front-back direction of the flying robot 10 as a rotation axis. The rotating unit 314 has a circular shape in a plan view. The rotation axis of the rotating unit 314 is positioned at the center of the rotating unit 314 in plan view. The rotating unit 314 emits laser light from its side surface in a direction perpendicular to the rotation axis. The laser light rotates as the rotating unit 314 rotates. The mirrors 311, 312, 313 are arranged such that the reflection surfaces 311 a, 312 a, 313 a respectively reflect the laser light incident from the rotating unit 314 in the forward direction of the flying robot 10. The mirrors 311, 312, 313 are arranged such that the reflection surfaces 311a, 312a, 313a are inclined at the same angle with respect to the plane parallel to the top, bottom, left and right. The tilt angles of the reflecting surfaces 311a, 312a, 313a with respect to the planes parallel to the top, bottom, left and right need not necessarily be the same.

  FIG. 2C is a diagram showing the configuration of the optical system held by the rotating unit 314.

  A light source 314a, a mirror 314b, a collimator lens 314c, a condenser lens 314d, a filter 314e, a mirror 314f, and a photodetector 314g are installed in the rotating unit 314. The light source 314a is, for example, a semiconductor laser that emits laser light having a predetermined wavelength. The laser light emitted from the light source 314a is reflected by the mirror 314b and then converted into parallel light by the collimator lens 314c. The laser light thus converted into parallel light is emitted from the side surface of the rotating unit 314, as indicated by the broken line arrow in FIG. After that, the laser light is reflected by any of the mirrors 311, 312, and 313, and irradiates the wall surface 2 shown in FIG.

  The laser light reflected by the wall surface 2 is condensed by the condenser lens 314d. The filter 314e cuts light having a wavelength other than the wavelength of the laser light emitted from the light source 314a. The laser light condensed by the condenser lens 314d passes through the filter 314e, is further reflected by the mirror 314f, and is converged on the photodetector 314g. The photodetector 314g outputs a signal according to the intensity of the received laser beam to the arithmetic processing unit 32 shown in FIGS. 2A and 2B.

  On the side surface of the rotating portion 314, for example, a laser light passage position from the collimator lens 314c toward the wall surface 2 and a laser light passage position from the wall surface 2 toward the condenser lens 314d are open. Alternatively, the entire side surface of the rotating portion 314 may be covered with a light-transmittable cover.

  During the wall surface measurement operation, the rotating unit 314 rotates while driving the light source 314a. As a result, the optical system of FIG. 2C, the light source 314a, and the photodetector 314g rotate integrally. Thus, as described above, the laser light emitted from the side surface of the rotating unit 314 rotates as the rotating unit 314 rotates. The light source 314a is oscillated in a pulse shape at a constant cycle. The arithmetic processing unit 32 measures the distance to the wall surface 2 based on the phase difference between the laser light emitted from the light source 314a and the laser light received by the photodetector 314g.

  FIG. 2D is a timing chart illustrating a method of measuring the distance to the object.

  The upper part of FIG. 2D shows a drive signal (pulse train) for driving the light source 314a, and the lower part of FIG. 2D shows a detection signal (pulse train) output from the photodetector 314g. The arithmetic processing unit 32 measures the distance to the position of the wall surface 2 irradiated with the laser light emitted at the timing t1 based on the phase difference D1 between the drive signal and the detection signal. Specifically, the arithmetic processing unit 32 calculates the distance by multiplying the phase difference D1 and the speed of light. Similarly at other timings, the distance to the wall surface 2 is measured. The distance to the wall surface 2 is measured by similar processing at the timing of other pulses.

  The laser light emitted from the rotating unit 314 to the wall surface 2 is not necessarily a pulse and may be a sine wave. For example, at each timing on the scanning path, a so-called chirp-type distance measuring method is used in which a wall surface 2 is irradiated with a sinusoidal laser beam for several cycles and the phase of light reflected from the wall surface 2 is detected by a detection circuit. May be. As a distance detection method using laser light, various conventionally known methods can be used.

  FIG. 3A is a diagram schematically showing the scanning path of the laser light when the rotating unit 314 is rotated. FIG. 3A shows a scanning path when the wall surface 2 perpendicular to the front-back direction of the wall surface measuring device 30 is seen through from the front side of the wall surface measuring device 30 toward the rear of the wall surface measuring device 30. FIG. 3A also shows the left, right, up and down directions of the flying robot 10 shown in FIG.

  The scanning path L1 is a scanning path in which the laser light moves on the wall surface 2 while the laser light emitted from the rotating unit 314 is incident on the reflecting surface 311a of FIG. The scanning path L2 is a scanning path through which the laser light moves on the wall surface 2 during a period in which the laser light emitted from the rotating unit 314 is incident on the reflection surface 312a of FIG. The scanning path L3 is a scanning path in which the laser light moves on the wall surface 2 while the laser light emitted from the rotating unit 314 is incident on the reflecting surface 313a of FIG.

  As shown in FIG. 3A, in this embodiment, three scanning paths L1, L2, L3 are set on the wall surface 2 by the three mirrors 311, 312, 313 shown in FIG. 2A. When the wall surface 2 is perpendicular to the front-back direction of the wall surface measuring device 30, that is, when the wall surface 2 is a plane that directly faces the wall surface measuring device 30, as shown in FIG. 3A, the scanning paths L1, L2, L3 is set to be substantially along each side of the triangle.

  The arithmetic processing unit 32 shown in FIGS. 2(a) and 2(b) performs scanning paths L1, L2, L3 shown in FIG. 3(a) based on the detection signal from the photodetector 314g of FIG. 2(c). Along this, the distance to the wall surface 2 is measured at predetermined intervals. Then, the arithmetic processing unit 32 acquires a three-dimensional coordinate point group during one rotation of the rotating unit 314 from the measured distance and the scanning position of the laser light at that timing, and the acquired three-dimensional coordinate point group. A plane matching with is acquired as the wall surface 2.

  Since the origin of distance measurement of the laser light reflected by the three mirrors 311, 312, 313 is the mirror image position of the light source 314a, the origin positions of the mirrors 311, 312, 313 are different. Therefore, the arithmetic processing unit 32 calculates the three-dimensional position of the light spot (irradiation point of laser light) on the wall surface 2 based on the distance from the starting position for each of the mirrors 311, 312, and 313.

  FIG. 3B is a diagram for explaining a method of detecting the wall surface 2. This detection method is a method for detecting the wall surface 2 based on Hough transform.

In FIG. 3B, the point O(0,0,0) is the viewpoint (first principal point) of the imaging device 40. The imaging direction of the imaging device 40 is the y-axis direction in FIG. In this case, the point O from the predetermined plane H on the beat was perpendicular foot point _{P (p x, p y,} p z), an arbitrary point other than the point P on the plane H _{Q (q} x, q _y , Q _z ), the following equation holds.

_{{P x, p y, p} z} · {(q x -p x), (q y -p y), (q z -p y)} T = 0 ... (1)

  Further, when the length of OP is represented by ρ and the direction of OP is represented by angles φ and θ shown in FIG. 3B, the following relationship is established.

p _x =ρ cos θ·cos φ
p _y =ρ cos θ·sin φ
p _z =ρ sin θ

For the search by voting, a triple loop that changes the plane H by swinging each variable in constant steps in the range of P1≦ρ≦P2, φ1≦φ≦φ2, θ1≦θ≦θ2 is configured. Inside this loop, for each three-dimensional coordinate point R(r _x , r _y , r _z ) obtained from the above distance measurement result, from the equation (1), e in the following equation is equal to or less than a constant value ε. In that case, cast one vote on the plane H.

e=p _x r _x +p _y r _y +p _z r _z −ρ ²

That is, when it can be considered that the plane H obtained by changing ρ, φ, and θ within the above range includes each three-dimensional coordinate point R (r _x , r _y , r _z ) of the distance measurement result, Cast one vote on the plane. This process is executed for all three-dimensional coordinate points R(r _x , r _y , r _z ) to be processed, and the number of votes (points) for the plane H is obtained. In this way, the plane H having the largest number of votes is acquired as the wall surface 2.

  The arithmetic processing unit 32 executes the above processing on the three-dimensional coordinate point group obtained by distance measurement based on the detection signal from the photodetector 314g of FIG. 2C, and the plane H that matches the three-dimensional coordinate point group. Is acquired as the wall surface 2. Then, the arithmetic processing unit 32 acquires the value of the variable ρ on the plane H acquired as the wall surface 2 as the distance to the wall surface 2, and also acquires the values of the variables φ and θ of the plane H as the inclination of the wall surface 2. ..

  FIG. 4 is a block diagram showing the configuration of the flying robot 10.

  The flying robot 10 includes a position detection unit 81, a propeller drive unit 82, a wireless communication unit 83, a control unit 84, and an interface 85.

  The position detection unit 81 includes the shaft 13, the pulley 14, and the encoder arranged on the rotation shaft of the pulley 14 shown in FIG. 1. The propeller drive unit 82 includes a motor that drives the propeller 11 shown in FIG. The wireless communication unit 83 communicates with the remote control device 60 shown in FIG. The control unit 84 includes a processing circuit such as a CPU (Central Processing Unit) and a memory such as a ROM (Read Only Memory) and a RAM (Random Access Memory), and controls each unit according to a program stored in the memory. The interface 85 is an interface for communicating with the wall surface measuring device 30 and the imaging device 40.

  The wall surface measuring device 30 includes a control unit 33 and an interface 34 in addition to the scan detection unit 31 and the arithmetic processing unit 32 shown in FIGS. The control unit 33 includes a processing circuit such as a CPU and a memory such as a ROM and a RAM, and controls each unit according to a program stored in the memory. The interface 34 is an interface for communicating with the control unit 84.

  The imaging device 40 includes a camera unit 41, an image processing unit 42, a control unit 43, and an interface 44. The camera unit 41 includes optical blocks such as an imaging lens and an image sensor. The image processing unit 42 compresses the imaged data input from the camera unit 41 by a predetermined compression method to generate image data. The control unit 43 includes a processing circuit such as a CPU and a memory such as a ROM and a RAM, and controls each unit according to a program stored in the memory. The interface 44 is an interface for communicating with the control unit 84 and the memory drive 50.

  During the wall surface inspection operation, the control unit 33 of the wall surface measuring device 30 transmits the distance to the wall surface 2 and the inclination of the wall surface 2 calculated by the arithmetic processing unit 32 to the control unit 84. The control unit 84 controls the propeller drive unit 82 based on the information received from the wall surface measuring device 30. Based on the distance to the wall surface 2 and the inclination of the wall surface 2 received from the arithmetic processing unit 32, the control unit 84 causes the imaging direction of the imaging device 40 to be substantially perpendicular to the wall surface 2, and the pulley 14 on the wall surface 2. Controls its own position and attitude to make contact.

  Further, during the wall surface inspection operation, the control unit 43 of the imaging device 40 transmits the image data generated by the image processing unit 42 to the control unit 84 at any time. The control unit 84 writes the received image data in the storage medium 51 held in the memory drive 50 in association with the position data indicating the position of the wall surface 2 detected by the position detection unit 81. At this time, the time data acquired by the clock (not shown) in the flying robot 10 is also stored in the storage medium 51. The clock in the flying robot 10 is set in advance with the clock of the information processing device 20.

  Note that the image data may be directly written in the storage medium 51 of the memory drive 50 by the control unit 43 of the imaging device 40. In this case, the control unit 84 on the main body side of the flying robot 10 writes the position data detected by the position detection unit 81 to the address corresponding to the image data on the storage medium 51 as needed.

  FIG. 5A is a flowchart showing the processing of the wall surface measuring device 30 during the wall surface measuring operation.

  The control unit 33 of the wall surface measurement device 30 drives the light source 314a of FIG. 2C to rotate the rotating unit 314 of FIGS. 2A and 2B once to scan the wall surface 2 with laser light. (S11). The control unit 33 causes the arithmetic processing unit 32 to perform a process of measuring the distance to the wall surface 2 at a predetermined interval in this scanning, and obtain a three-dimensional coordinate point group (S12). Further, the control unit 33 causes the arithmetic processing unit 32 to execute a process of measuring the inclination of the wall surface 2 based on the acquired three-dimensional coordinate point group (S13). The control unit 33 transmits the distance and the inclination measured by the arithmetic processing unit 32 to the control unit 84 on the main body of the flying robot 10 (S14).

  After that, the control unit 33 determines whether or not the end of the wall surface measuring operation is instructed (S15). When the end instruction of the wall surface measurement operation has not been issued (S15: NO), the control unit 33 returns the processing to step S11 and continues the measurement processing of the wall surface 2. When the end instruction of the wall surface measurement operation is issued (S15: NO), the control unit 33 ends the process.

  FIG. 5B is a flowchart showing the wall surface measurement process executed in step S13 of FIG. 5A.

  The arithmetic processing unit 32 sets the plane H by giving predetermined values to the variables ρ, φ, and θ, as described with reference to FIG. 3B (S101). When the set plane H includes the three-dimensional coordinate point R (S102: YES), the arithmetic processing unit 32 adds one point to the set plane H (S103). When the set plane H does not include the three-dimensional coordinate point R (S102: NO), the arithmetic processing unit 32 does not add one point to the set plane H. The arithmetic processing unit 32 executes the processing of steps S102 and S103 for all three-dimensional coordinate points (S104), and determines the score for the plane H.

  After that, the arithmetic processing unit 32 determines whether or not the processes of steps S102 to S104 have been completed for all planes H in the range in which the variables ρ, φ, and θ can be changed (S105). When the processes of steps S102 to S104 have not been completed for all the planes H (S105: NO), the arithmetic processing unit 32 sets a new plane H by giving predetermined values to the variables ρ, φ, and θ. Yes (S101). Then, the arithmetic processing unit 32 executes the processing of steps S102 to S104 on the newly set plane H to determine the score for the plane H.

  After determining the scores for all the planes H (S105: YES), the arithmetic processing unit 32 sets the plane H having the highest score on the wall surface 2 (S106). Then, the distance to the plane H, that is, ρ in FIG. 3B is acquired as the distance to the wall surface 2, and the inclination of this plane H, that is, φ and θ in FIG. 3B, is the inclination of the wall surface 2. To get as. The distance ρ and the inclinations φ and θ are transmitted to the control unit 84 on the main body side of the flying robot 10 by the process of step S14 of FIG. In response to this, the control unit 84 of the flying robot 10 controls its own position and attitude as described above.

  Regarding the three-dimensional coordinate point group acquired in step S12 of FIG. 5A, the coordinate points too close to the flying robot 10 and the coordinate points too far from the flying robot 10 may be excluded from the processing target in step S13. preferable. For example, with respect to the distance from the wall surface measuring device 30 determined by the shaft 13 and the pulley 14 in FIG. 1, thresholds of distances are set in a direction approaching the flight robot 10 and a direction departing from the flight robot 10, and the distance is out of the range between these thresholds. Exclude the coordinate points of the distance from the processing target. This can reduce the time required for the arithmetic processing. When the number of excluded coordinate points is large, it may be determined that the inspection position of the wall surface 2 is near the end of the wall surface 2, or it may be determined that the distance search is abnormal.

  Further, when the step of FIG. 5A is executed after the second time, the wall surface H set in step S101 of FIG. 5B is based on the wall surface of the distance and the inclination calculated in the previous step. It is preferable to set the parameters by shaking them in a predetermined range. By doing so, the range of parameters for shaking the wall surface H can be minimized, and the wall surface search processing based on the Hough transform can be speeded up.

  As described above, regarding the three-dimensional coordinate point group acquired in step S12 of FIG. 5A, the coordinate points that are too close to the flying robot 10 and the coordinate points that are too far from the flying robot 10 are selected from the processing targets in step S13. In the case of excluding, if the ratio of the excluding coordinate points to the whole coordinate points is large, the inspection position of the wall surface 2 may be near the end of the wall surface 2. In this case, it can be assumed that the inspection position is approaching the corner portion where another wall surface follows the end of the wall surface 2. Therefore, when the ratio of coordinate points to be excluded is large as described above, it is determined whether the plane H having the second highest score or the plane H having the third highest score can be a plane connected to the plane H having the highest score. May be. When it can be determined that these planes H can be connected to the plane H having the highest score, it is determined that the plane H having the highest score is the plane of the wall surface H to be inspected in front of the flying robot 10. May be.

<Effects of the embodiment>
According to this embodiment, the following effects can be achieved.

  The wall surface measuring device 30 need only be provided with a rotating unit 314 that rotates about one axis and mirrors 311, 312, and 313 that reflect the laser light, as a configuration for scanning the laser light. Therefore, the mass of the wall surface measuring device 30 can be significantly reduced as compared with the case where two actuators for individually scanning the laser light in the horizontal direction and the vertical direction are provided. Therefore, when the wall surface measuring device 30 is mounted on the flying robot 10, the load on the flying robot 10 can be effectively suppressed. Further, since the rotating unit 314 and the mirrors 311, 312, 313 are arranged, the wall surface measuring device 30 can be simplified and downsized. Therefore, also from this point, the wall surface measuring device 30 can be smoothly mounted on the flying robot 10.

  Further, in the present embodiment, as shown in FIGS. 2A and 2B, the optical axis of the laser light is bent by the three mirrors 311, 312, 313 arranged so as to surround the rotating portion 314. , The wall surface 2 is scanned by three scanning paths L1, L2, L3 corresponding to each mirror. In this manner, by scanning the wall surface 2 with the three scanning paths L1, L2, and L3, the number of coordinate point groups can be increased while dispersing the three-dimensional coordinate point group used for searching the wall surface 2. Therefore, the search accuracy of the wall surface 2 can be improved.

  Further, in the present embodiment, as shown in FIG. 3A, the wall surface 2 is searched by scanning the laser light on three scanning paths L1, L2, and L3 substantially along the triangle. For this reason, the searched wall surface 2 is unlikely to cause an inclination error (blurring) in any direction with respect to the regular wall surface. Therefore, the measurement accuracy of the wall surface 2 can be improved.

  Further, in the present embodiment, as shown in FIGS. 2A and 2B, the reflecting surfaces 311a, 312a, 313a of the mirrors 311, 312, 313 have a plane shape and a shape elongated in one direction. The mirrors 311, 312, 313 are arranged so that the optical axis of the laser beam moves in the longitudinal direction of the reflecting surfaces 311a, 312a, 313a as the rotating section 314 rotates. Thereby, the scanning loci L1, L2, L3 on the wall surface 2 can be set in three directions while using the mirrors 311, 312, 313 having a simple structure. Therefore, the measurement accuracy of the wall surface 2 can be improved.

  Further, in the present embodiment, as described with reference to FIG. 3B, the arithmetic processing unit 32 changes the distance to the plane H and the inclination of the plane H to change the three-dimensional shape included in the plane H. The number of coordinate point groups is counted, and the plane H having the largest counted number is acquired as the wall surface 2. Thereby, the wall surface 2 can be detected smoothly and accurately from the three-dimensional coordinate point group.

  Further, since the flight robot 10 is equipped with the wall surface measuring device 30 whose mass is suppressed as described above, the load during flight is reduced. Therefore, it is possible to smoothly and stably fly to the target wall surface position and image the wall surface 2. Furthermore, since the wall surface inspection system 1 uses the flight robot 10 having such a configuration, the wall surface 2 can be smoothly and stably imaged, and the wall surface 2 can be smoothly inspected.

  Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and the embodiment of the present invention can be modified in various ways other than the above.

<Modification 1>
In the above embodiment, the three scanning paths L1, L2, L3 are set on the wall surface 2 by using the three mirrors 311, 312, 313. On the other hand, in the first modification, the mirror 311 is omitted, and the two scanning paths L1, L2, and L3 are set on the wall surface 2 by using the two mirrors 312 and 313.

  6A and 6B are a plan view and a side view, respectively, showing the configuration of the scan detection unit 31 according to the first modification. 6A and 6B show the front-back, left-right, and up-down directions of the flying robot 10 shown in FIG. 2A and 2B, the arithmetic processing unit 32 is shown together with the scanning detection unit 31. The arithmetic processing unit 32 calculates the distance to the wall surface 2 and the inclination of the wall surface 2 based on the signal output from the scanning detection unit 31, as in the above embodiment.

  As shown in FIGS. 6A and 6B, in the scan detection unit 31 of the wall surface measuring device 30, two mirrors 312 and 313 are arranged so as to sandwich the rotating unit 314. Then, the optical axis of the laser beam emitted from the side surface of the rotating unit 314 is bent by these two mirrors 312 and 313, so that the wall surface 2 is scanned by three scanning paths including two scanning paths corresponding to each mirror. Is configured. The configuration of the rotating unit 314 is similar to that of the above-mentioned embodiment.

  The front-back direction and the vertical direction in FIGS. 6A and 6B are different from the front-back direction and the vertical direction in FIGS. 2A and 2B. That is, in the first modification, the tilt angles of the reflecting surfaces 312a and 313a with respect to the planes parallel to the upper, lower, left and right sides are as shown in FIGS. It is set so as to approach 90 degrees as compared with the case. More specifically, on the wall surface 2 perpendicular to the front-rear direction, the laser light reflected in the front direction by the reflection surfaces 312a and 313a follows the scanning paths L2 and L3 of FIG. 6C, respectively. The tilt angles and arrangements of 312a and 313a are adjusted. The scanning path L1 in FIG. 6C is the scanning path of the laser light set on the wall surface 2 during the period in which the laser light passes through the gap on the front side of the mirrors 312 and 313.

  Scanning paths L1, L2, L3 shown in FIG. 6C are scanning paths of laser light on the wall surface 2 when the wall surface 2 perpendicular to the front-back direction is viewed from the wall surface measuring device 30 side in the front direction. .. When the rotating unit 314 rotates in the range where the laser light passes through the gaps on the front side of the mirrors 312 and 313, the wall surface 2 is scanned with the laser light along the scanning path L1. Further, when the rotating unit 314 rotates in the range where the laser light is incident on the reflection surface 312a of the mirror 312, the wall surface 2 is scanned with the laser light along the scanning path L2, and the laser light is incident on the reflection surface 313a of the mirror 313. When the rotating unit 314 rotates in the range, the wall surface 2 is scanned with the laser light along the scanning path L3.

  With the scan detection unit 31 of the first modification, the scan paths L1, L2, and L3 can be set on the wall surface 2 substantially along each side of the triangle, as in the above embodiment. Therefore, the wall surface 2 can be detected with the same accuracy as in the above embodiment.

  Further, in the second modification, the number of mirrors 311 is reduced as compared with the above-described embodiment, so that the mass of the wall surface measuring device 30 can be further suppressed. Therefore, the load on the flying robot 10 can be further reduced, and the flying robot 10 can be caused to fly more smoothly and stably near the target wall surface position.

<Modification 2>
7A and 7B are a plan view and a side view, respectively, showing the configuration of the scan detection unit 31 according to the second modification. FIG. 7C is a diagram schematically showing the scanning paths L1 and L2 according to the second modification.

  The scan detection unit 31 of the second modification has a configuration in which the mirror 313 is omitted from the scan detection unit 31 of the first modification. Therefore, the scanning path set on the wall surface 2 is only the scanning paths L1 and L2, with the scanning path L3 of FIG. 6C omitted. The arithmetic processing unit 32 acquires the three-dimensional coordinate point group and detects the wall surface 2 in the period in which the laser light follows the scanning paths L1 and L2, and measures the distance to the wall surface 2 and the inclination of the wall surface 2. The detection process of the wall surface 2 is the same as that in the above embodiment.

  The wall surface 2 can be properly detected also in the second modification. However, since the scanning path L3 is omitted, the number of three-dimensional coordinate point groups used for detecting the wall surface 2 is reduced as compared with the above-described embodiment and the first modification. Therefore, in this modified example, the detection accuracy of the wall surface 2 is slightly reduced as compared with the above-described embodiment and the modified example 1.

  On the other hand, in the second modification, since the mirror 313 is further omitted, the mass of the wall surface measuring device 30 can be further suppressed. Therefore, the load on the flying robot 10 can be significantly reduced. This allows the flying robot 10 to fly smoothly and stably near the target wall surface position.

<Modification 3>
FIGS. 8A and 8B are a plan view and a side view, respectively, showing the configuration of the scanning detection unit 31 according to the third modification. FIG. 8C is a diagram schematically showing the scanning paths L1 and L2 according to the third modification.

  The scanning detection unit 31 of the third modification has a configuration in which the mirror 311 is omitted from the scanning detection unit 31 of the above embodiment. Therefore, the scanning path set on the wall surface 2 is only the scanning paths L2 and L3, with the scanning path L1 in FIG. 6C omitted. The arithmetic processing unit 32 acquires the three-dimensional coordinate point group and detects the wall surface 2 in the period in which the laser light follows the scanning paths L2 and L3, and measures the distance to the wall surface 2 and the inclination of the wall surface 2. The detection process of the wall surface 2 is the same as that in the above embodiment.

  The wall surface 2 can be properly detected also in the third modification. However, since the scanning path L1 is omitted, the number of three-dimensional coordinate point groups used for detecting the wall surface 2 is reduced as compared with the above-described embodiment and modification 1. Therefore, in this modified example, the detection accuracy of the wall surface 2 is slightly reduced as compared with the above-described embodiment and the modified example 1.

<Other changes>
In the above-described embodiment and the first to third modifications, the scanning path of the laser beam is set so as to be substantially along the three sides or the two sides of the triangle, but the method for setting the scanning path is not limited to this. For example, only one scanning path may be set along an arc-shaped curve having a radius of curvature that is somewhat small. The scanning path can be changed as appropriate as long as the three-dimensional coordinate point groups acquired along the scanning path are dispersed in the three-dimensional space so that one plane can be specified.

  Further, in the above-described embodiment and the modified examples 1 to 3, the detection method of the wall surface 2 based on the Hough transform is used, but the detection method of the wall surface 2 is not limited to this. For example, an approximate straight line corresponding to each scanning locus is obtained from the three-dimensional coordinate point group by the method of least squares, and the obtained approximate straight line is compared with a reference straight line held in advance for each distance and inclination of the wall surface 2, The distance and slope corresponding to the reference straight line that best matches the approximate straight line may be acquired as the distance and slope of the wall surface 2.

  Further, in the above-described embodiment and Modifications 1 to 3, the reflecting surfaces 311a, 312a, 313a of the mirrors 311, 312, 313 are flat surfaces, but the reflecting surfaces 311a, 312a, 313a do not necessarily have to be flat surfaces. .. Some or all of the reflecting surfaces 311a, 312a, 313a may be curved so that a desired scanning path is set on the wall surface 2.

  Further, in the above embodiment and Modifications 1 to 3, the flying robot 10 is equipped with the memory drive 50, and the image data and the position data of the wall surface 2 are stored in the storage medium mounted in the memory drive 50. The memory drive 50 may be omitted, and the image data and the position data of the wall surface 2 may be transmitted from the flying robot 10 to the information processing device 20 at any time by wireless communication. Alternatively, the remote control device 60 is configured such that the storage medium can be attached and detached, and the image data and the position data of the wall surface 2 are transmitted from the flying robot 10 to the remote control device 60 by wireless communication and stored in the storage medium. You may do so.

  In addition, the embodiment of the present invention can be appropriately modified in various ways within the scope of the technical idea described in the claims.

1... Wall surface inspection system 10... Flying robot 20... Information processing device 30... Wall surface measuring device 31... Scan detection part 32... Arithmetic processing part 311, 312, 313... Mirror 314... Rotating part 314a... Light source 314h... Photodetector 40... Imaging device 82... Propeller drive unit

Claims (10)

A light source that emits laser light,
A photodetector for receiving the laser light reflected from an object,
A rotating unit that integrally rotates the light source and the photodetector about one axis;
A support member that supports the rotating portion,
A mirror that is installed on the support member and that reflects the laser light emitted from the light source in a part of a rotation range of the rotating unit,
Based on a signal output from the photodetector, a wall surface of the object at the position irradiated with the laser light, an arithmetic processing unit for calculating a distance to the wall surface and an inclination, respectively,
The mirror is configured so that the object is scanned by a plurality of scanning paths different from each other with the rotation of the rotating unit,
The arithmetic processing unit acquires, as a wall surface of the object, a plane that matches a three-dimensional coordinate point group obtained by measuring distances to the object along the plurality of scanning paths.
A wall surface measuring device characterized in that The three mirrors are arranged so as to surround the rotating part,
The wall surface measuring device according to claim 1, wherein the object is scanned along three scanning paths corresponding to each mirror by bending the optical axis of the laser light emitted from the light source by the three mirrors. The two mirrors are arranged so as to sandwich the rotating portion,
The object is scanned in a plurality of scanning paths including two scanning paths corresponding to each mirror by bending the optical axis of the laser light emitted from the light source by the two mirrors. Wall measuring device.   The object is scanned by a scanning path generated when the laser light passes through a gap between the two mirrors and two scanning paths generated when the laser light is reflected by the two mirrors. The wall surface measuring apparatus according to claim 3, wherein the two mirrors are arranged in the. One of the mirrors is arranged around the rotating part,
The mirror is arranged so that the object is scanned by a scanning path generated when the laser light passes through a region where the mirror is not arranged and a scanning path generated when the laser light is reflected by the mirror. The wall surface measuring device according to claim 1, wherein   The wall surface measuring apparatus according to claim 1, wherein the plurality of scanning paths are set so as to substantially follow each side of a triangle in a plane that directly faces the wall surface measuring apparatus. The reflecting surface of the mirror has a flat surface and a shape elongated in one direction,
7. The wall surface measuring device according to claim 1, wherein the mirror is arranged so that the optical axis of the laser light moves in the longitudinal direction of the reflecting surface as the rotating unit rotates. ..   The arithmetic processing unit changes the distance to the plane and the inclination of the plane to count the number of the coordinate point groups included in the plane, and acquires the plane with the largest number as the wall surface of the object. The wall surface measuring device according to any one of claims 1 to 7. A wall surface measuring device according to any one of claims 1 to 8,
An imaging device for imaging the wall surface;
Propeller drive for flying stationary,
A flying robot comprising: a control unit that controls a flight attitude based on a measurement result by the wall surface measuring device. A flying robot according to claim 9;
A wall surface inspection system, comprising: an information processing device that processes an image captured by the image capturing device to evaluate a situation of the wall surface.

Images