Flying Rock Analysis System and Flying Rock Analysis Method

Abstract

To provide a scattered stone analysis system and a scattered stone analysis method which allow a user to know the scattering state of a scattered stone generated in the crushing work.SOLUTION: A scattered stone analysis system 1 for analyzing the scattering state of a scattered stone generated in the crushing work by a construction machine 2 being a crusher comprises: an imaging unit 3 which images a range including the generation spot of the scattered stone; and a processing unit 4 which obtains movement information about the movement of the scattered stone by means of a frame difference method. The imaging unit 3 is a stereo camera. The processing unit 4 calculates the movement information from a first photographed image by a first camera 31 and a second photographed image by a second camera 32.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a flying rock analysis system and a flying rock analysis method for analyzing the flying state of flying rocks scattered around during crushing work.

Background Art

[0002] In civil engineering work and road repair work, etc., crushing work is carried out to crush rock masses, concrete pavement surfaces, and asphalt pavement surfaces with a crusher. In the crushing work, flying rocks (crushed pieces) scatter around, so safety measures and avoidance measures may be taken to protect workers and the surrounding environment from the flying rocks. The safety measures are, for example, setting a predetermined range as a restricted access area, installing a protective fence, etc. (see, for example, Patent Document 1). The avoidance measure is, for example, a change in the construction method.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Currently, there is no method to clearly know the flying state of flying rocks generated by crushing work, and the experience of workers is required to take appropriate safety measures and avoidance measures. From such a perspective, the present invention provides a flying rock analysis system and a flying rock analysis method capable of knowing the flying state of flying rocks generated by crushing work.

Means for Solving the Problems

[0005] The flying rock analysis system according to the present invention is a flying rock analysis system for analyzing the flying state of flying rocks generated by crushing work with a crusher. This rockfall analysis system includes a photographing unit that photographs a range including the occurrence point of the rockfall, and a As a computer processing unit that obtains motion information regarding the motion of the rockfall by the frame difference method. The photographing unit is a stereo camera, and the processing unit calculates the motion information from a first photographed image by a first camera and a second photographed image by a second camera. The processing unit includes, for example, a difference image creation unit and a motion information calculation unit. The difference image creation unit creates a first frame difference image that is a difference between the first photographed images continuous in time series, and creates a second frame difference image that is a difference between the second photographed images continuous in time series. The motion information calculation unit performs stereo analysis based on the first frame difference image and the second frame difference image Calculate the position of the flying rock and calculate the arrival point of the flying rock based on the calculated position of the flying rock. For example, the motion information calculation unit causes the display unit to display the first viewpoint trajectory of the flying rock based on the first camera, accepts the input of the position information of the first vertex via the input unit, and causes the display unit to display the second viewpoint trajectory of the flying rock based on the second camera, accepts the input of the position information of the second vertex via the input unit, and calculates the arrival point from the relationship between the input first vertex and second vertex and the generation point. In addition, the motion information calculation unit causes the display unit to display the first viewpoint positions that are continuous in time series of the flying rock based on the first camera, accepts the input of the position information at a plurality of time points via the input unit, and causes the display unit to display the second viewpoint positions that are continuous in time series of the flying rock based on the second camera, accepts the input of the position information at a plurality of time points via the input unit, and calculates the arrival point from the relationship between the input first viewpoint position and second viewpoint position and the generation point. In the rockfall analysis system according to the present invention, by analyzing the photographed images taken by the stereo camera, it is possible to detect the motion (position, velocity, energy, etc.) of the rockfall scattered in various directions (particularly, the optical axis direction of the camera). When photographing is performed with a monocular camera, since the rockfall spreads radially in multiple directions, it is difficult to accurately detect the motion in the optical axis direction of the camera. Also, even when the arrival point of the flying rock cannot be photographed (even when the flying rock jumps out of the photographing range), the arrival point of the flying rock can be estimated. Therefore, it is possible to cope with various scattering situations of the flying rock.

[0006] Pre The motion information calculation unit may further obtain the motion energy of the rockfall using information regarding the type of the object to be crushed. By doing so, it is possible to know in more detail the influence exerted by the rockfall on the surroundings.

[0007] The rockfall analysis method according to the present invention is a rockfall analysis method for analyzing the scattering state of rockfalls generated by a crushing operation using a crusher. This rockfall analysis method includes a photographing step of photographing a range including the occurrence point of the rockfall, and The computer a processing step of obtaining motion information regarding the motion of the rockfall by the frame difference method. In the photographing step, photographing is performed using a stereo camera, and in the processing step, the motion information is calculated from the first photographed image by the first camera and the second photographed image by the second camera. In the above processing steps, for example, a differential image creation step and a motion information calculation step are performed. In the differential image creation step, a first frame difference image that is the difference between the first captured images that are continuous in time series is created, and a second frame difference image that is the difference between the second captured images that are continuous in time series is created. In the motion information calculation step, the position of the flying rock is calculated by stereo analysis based on the first frame difference image and the second frame difference image, and the arrival point of the flying rock is calculated based on the calculated position of the flying rock. For example, in the motion information calculation step, the display unit is caused to display the first viewpoint trajectory of the flying rock based on the first camera, the input of the position information of the first vertex is accepted via the input unit, the display unit is caused to display the second viewpoint trajectory of the flying rock based on the second camera, the input of the position information of the second vertex is accepted via the input unit, and the arrival point is calculated from the relationship between the input first vertex and second vertex and the generation point. In the movement information calculation step, the first viewpoint positions of the flying stones that are continuous in the time series based on the first camera are displayed on the display unit, and the input of position information at a plurality of time points is received via the input unit. At the same time, the second viewpoint positions of the flying stones that are continuous in the time series based on the second camera are displayed on the display unit, and the input of position information at a plurality of time points is received via the input unit. The arrival point is calculated from the relationship between the input first viewpoint position, the second viewpoint position, and the generation point. In the flying rock analysis method according to the present invention, by analyzing the photographed image taken by a stereo camera, it is possible to detect the motion (position, velocity, energy, etc.) of flying rocks scattered in various directions (particularly, the optical axis direction of the camera). Also, even when the arrival point of the flying stone cannot be photographed (even when the flying stone jumps out of the photographing range), the arrival point of the flying stone can be estimated. Therefore, it is possible to cope with various scattering situations of the flying stones.

Effect of the Invention

[0008] According to the present invention, it is possible to know the scattering situation of flying rocks generated by crushing work.

Brief Description of the Drawings

[0009]

Figure 1

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Embodiments for Carrying Out the Invention

[0010] Hereinafter, embodiments for carrying out the present invention will be described in detail with appropriate reference to the drawings. Each drawing only schematically shows to the extent that the present invention can be sufficiently understood. Therefore, the present invention is not limited only to the illustrated examples. In each drawing, common components and similar components are denoted by the same reference numerals, and their overlapping descriptions are omitted. <Configuration of the Flying Rock Analysis System According to the Embodiment> With reference to FIG. 1, the configuration of the flying rock analysis system 1 according to the embodiment will be described. FIG. 1 is a schematic configuration diagram of the flying rock analysis system 1 according to the embodiment. The flying rock analysis system 1 is a system for analyzing the scattering situation of flying rocks generated by the crushing operation of a crusher. The flying rock analysis system 1 can be used in various scenes where flying rocks are generated by the crushing operation, and the flying rocks to be analyzed are not limited in terms of shape, size, type (for example, rock type), etc. Here, as shown in FIG. 1, it is assumed that the flying rock analysis system 1 is used for the crushing operation of the rock mass 9 by the construction machine 2 (crusher) equipped with the breaker 2a. Therefore, in the present embodiment, the object to be crushed (sometimes referred to as the "object to be crushed") is the rock mass 9.

[0011] As shown in Fig. 1, the rockfall analysis system 1 includes a photographing unit 3 and a processing unit 4. As described above, the rockfall analysis system 1 analyzes the scattering state of the rockfall 8 (see Fig. 3) generated during the operation of crushing the rock mass 9 as the object to be crushed by the construction machine 2. Here, the rock mass 9 is a flat ground. The construction machine 2 is provided with a breaker 2a, and the working area 9a set on the rock mass 9 is crushed using the breaker 2a. The photographing unit 3 photographs the crushing operation by the construction machine 2. The photographing unit 3 is a stereo camera including a plurality of cameras. The photographing unit 3 in the present embodiment is a stereo camera in which two cameras are arranged side by side on the left and right. The stereo camera simultaneously photographs an object from a plurality of different directions using two cameras in the same principle as a human seeing an object. Therefore, according to the stereo camera, it is possible to measure the information in the depth direction from the position information of the pixels of the camera. The photographing unit 3 is installed to photograph, for example, a range including the occurrence point of the rockfall 8 (see Fig. 3). The photographing unit 3 outputs the photographed video to the processing unit 4. The processing unit 4 is a computer composed of a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), etc., acquires the video photographed by the photographing unit 3, and obtains motion information regarding the motion of the rockfall 8 based on this video. Although details will be described later, the processing unit 4 performs a process combining a three-dimensional image analysis technique (stereo image analysis technique) using the video (a plurality of images at the same time) photographed by the stereo camera and an image analysis technique (frame difference technique) of a moving object using images continuous in time series.

[0012] As shown in FIG. 1, the imaging unit 3 in the present embodiment includes a first camera 31 disposed on the left side facing the object to be crushed (here, the rock mass 9 within the range where the work area 9a is set), and a second camera 32 disposed on the right side facing the object to be crushed. The imaging unit 3 may be manufactured for a stereo camera, or may be used as a stereo camera by synchronizing two monocular cameras. In the case of a configuration for synchronizing two monocular cameras, the width between the monocular cameras can be freely changed. The first camera 31 and the second camera 32 are preferably high-resolution video cameras or digital cameras capable of acquiring digital still images at a predetermined frame rate. The first camera 31 and the second camera 32 are arranged and set to correspond to stereo image analysis described later. For example, the optical axes of the first camera 31 and the second camera 32 are parallel to each other and horizontal. In the present embodiment, the first camera 31 and the second camera 32 are arranged side by side on the same horizontal plane. Note that the arrangement of the first camera 31 and the second camera 32 is not limited to the arrangement side by side in the left-right direction. FIG. 2 is a front view of the photographing unit 3. As shown in FIG. 2, the two cameras 31 and 32 are connected by a connecting portion 33, and the connecting portion 33 is further installed on a tripod 34. As shown in FIG. 1, the two cameras 31 and 32 are arranged at a position separated from the work area 9a by a predetermined distance (for example, several meters), and photograph the crushing operation by the construction machine 2 from the side of the construction machine 2. An image of the first photographed image Ea (a frame constituting a video) photographed by the first camera 31 is shown in FIG. 3. As shown in FIG. 3, the first photographed image Ea photographed by the first camera 31 shows flying stones 8, the breaker 2a, the generation point (drill tip) of the flying stones 8, and the like. Although not shown, similarly, the second photographed image Eb photographed by the second camera 32 also shows flying stones 8, the breaker 2a, the generation point (drill tip) of the flying stones 8, and the like. The second photographed image Eb in the present embodiment is a video obtained by photographing the object to be crushed from the right side of the first photographed image Ea. In some cases, when explaining the first photographed image Ea and the second photographed image Eb without distinction, they may be referred to as "photographed image E". Further, based on the positional relationship between the first camera 31 and the second camera 32, the first camera 31 may be referred to as the "left camera", and its video may be referred to as the "left video", and the second camera 32 may be referred to as the "right camera", and its video may be referred to as the "right video". The photographing unit 3 outputs the videos photographed by the two cameras 31 and 32 to the processing unit 4.

[0013] Referring to FIG. 4, the configuration of the processing unit 4 will be described. FIG. 4 is a configuration diagram of the processing unit 4. The processing unit 4 mainly includes a display unit 41, an input unit 42, a communication unit 43, a storage unit 44, and a control unit 45. The display unit 41 is, for example, a liquid crystal display, and displays the analysis result of the flying stones 8 and the like. The input unit 42 is, for example, a keyboard or a mouse, and information used for the analysis of the flying stones 8 is input. Note that the display unit 41 and the input unit 42 may be configured as a touch display capable of displaying and inputting on one screen. The communication unit 43 is, for example, a network card, and enables communication (data transmission and reception) with the photographing unit 3. Note that the communication unit 43 may perform wireless communication with the photographing unit 3. The storage unit 44 is a storage medium such as a RAM (Random Access Memory), a ROM (Read Only Memory), an HDD (Hard Disk Drive), or a flash memory, and stores information used for the analysis of the flying rock 8. The control unit 45 includes a differential image creation unit 46 and a motion information calculation unit 47. The functions of the control unit 45 are realized by program execution processing by a CPU (Central Processing Unit) or a dedicated circuit or the like. When the functions of the control unit 45 are realized by program execution processing, a program for realizing the functions of the control unit 45 is stored in the storage unit 44.

[0014] The differential image creation unit 46 shown in FIG. 4 performs image analysis of a moving object (here, the flying rock 8) by the frame difference method. With reference to FIG. 5, the processing of the differential image creation unit 46 will be described. FIG. 5 is a diagram showing the flow of obtaining the trajectory of a moving object by the frame difference method. The frame difference method is a method of detecting a moving object by taking the difference between images (frames) that are continuous in time series. In the frame difference method, for the captured images E for the past N frames (N≥3, and for example, about N = 10 is appropriate), the difference between two captured images E that are continuous in time series is taken (the RGB values of each pixel are subtracted) to generate a frame difference image F, and threshold processing is performed to extract the region of the moving object (here, the flying rock 8) from each frame difference image F. The upper part of FIG. 5 shows the captured images E that are continuous in time series, and the middle part of FIG. 5 shows the frame difference image F obtained from two consecutive captured images E. In FIG. 5, the case where the frame difference image F1 is generated from the captured images E1 and E2, the frame difference image F2 is generated from the captured images E2 and E3, and the frame difference image F3 is generated from the captured images E3 and E4 is shown. In the frame difference image F, the region where there is no change in two consecutive captured images E in time series is represented by black (≈0), and the region where there is a change due to the capture of a moving object such as the flying rock 8 is shown in white (≠0). Note that although the breaker 2a may be displayed in the frame difference images F1 to F3, it is omitted in FIG. 5. Also, a frame difference composite image G is generated by synthesizing the frame difference images F, and the union of the regions of the moving object (here, the flying rock 8) is obtained. FIG. 5 shows the case where the frame difference composite image G is generated from the frame difference images F1, F2, F3, ···. By synthesizing consecutive frame difference images F, the trajectory of the moving object (here, the flying rock 8) can be visualized. The differential image creation unit 46 creates two frame difference composite images G based on the first captured image Ea captured by the first camera 31 (left camera) and the second captured image Eb captured by the second camera 32 (right camera) (see Fig. 6). Fig. 6 is a diagram showing the visualized trajectory of the flying rock 8. (a) is the first frame difference composite image Ga based on the first captured image Ea captured by the first camera 31 (left camera), and (b) is the second frame difference composite image Gb based on the second captured image Eb captured by the second camera 32 (right camera). The first frame difference composite image Ga shown in Fig. 6(a) displays the first viewpoint positions that are continuous in the time series of the flying rock 8 based on the first camera 31. In the first frame difference composite image Ga, the first viewpoint position is displayed as a white object. By displaying the images (white objects) of the flying rock 8 captured by the first camera 31 at a predetermined frame rate in the first frame difference composite image Ga, the trajectory (parabola) of the flying rock 8 can be recognized. Also, the second frame difference composite image Gb shown in Fig. 6(b) displays the second viewpoint positions that are continuous in the time series of the flying rock 8 based on the second camera 32. In the second frame difference composite image Gb, the second viewpoint position is displayed as a white object. By displaying the images (white objects) of the flying rock 8 captured by the second camera 32 at a predetermined frame rate in the second frame difference composite image Gb, the trajectory (parabola) of the flying rock 8 can be recognized.

[0015] The motion information calculation unit 47 shown in FIG. 4 calculates the three-dimensional coordinates of the object (here, the flying rock 8) by stereo image analysis. With reference to FIG. 7, the principle of stereo image analysis will be described. FIG. 7 is a three-dimensional stereo geometric model. When shooting with a stereo camera, there is a difference in the two-dimensional positions of the object projected onto each image. In stereo image analysis, the distance to the object is calculated using the principle of triangulation from the difference in the positions of the object projected onto each image. Thereby, the three-dimensional position coordinates of the object can be obtained. For stereo image analysis, for example, the distance between the lenses of the two cameras constituting the stereo camera, the focal length of the camera, and the two-dimensional coordinates of the object shown in the captured images Ea and Eb captured by the two cameras are used. Here, the two cameras constituting the stereo camera need to satisfy, for example, the following three conditions. · Make the focal lengths equal. · The imaging planes are on the same plane. · The imaging planes are on a straight line. As shown in FIG. 7, let the distance between the two cameras 31 and 32 be B and the focal length of the camera be f. Also, assume that the object P is at the positions P L (x L ,y L ) and P R (x R ,y R ) on the imaging planes (the first captured image Ea, the second captured image Eb) of the two cameras 31 and 32, respectively, and let the parallax "x L -x R ", which is the deviation of the projection position of the object P, be d. In this case, the three-dimensional position coordinates (X, Y, Z) of the object P are represented by the following equation (1).

Equation

[0016] In this embodiment, the motion information calculation unit 47 obtains motion information regarding the motion of the flying rock 8 by performing stereo image analysis using the frame difference composite images Ga and Gb (see FIG. 6) created from the left and right images (captured images Ea and Eb) of the stereo camera. The motion information includes information such as the position, velocity, and energy of the flying rock 8. For example, the motion information includes a collection of three-dimensional positions of the flying rock 8 at each predetermined time (a set of discontinuous position information). Also, the motion information may not be information regarding the entire trajectory of the flying rock 8 (the trajectory from the generation point to the arrival point), but may be information regarding a partial trajectory (for example, the trajectory from the generation point to an intermediate point). When the motion information calculation unit 47 obtains a partial trajectory of the flying rock 8 by performing stereo image analysis, it may further calculate the remaining trajectory to the arrival point. Also, the motion information calculation unit 47 may calculate new information other than the trajectory from the trajectory of the flying rock 8 (for example, the kinetic energy of the flying rock 8). Note that what information content the motion information calculation unit 47 calculates as the motion information is related to, for example, the purpose of analyzing the scattering state of the flying rock 8 and the shooting range of the shooting unit 3 (whether the arrival point of the flying rock 8 can be captured).

[0017] Hereinafter, the processing in the case of calculating the flight distance from the generation point to the arrival point of the flying rock 8 as the motion information of the flying rock 8 will be described. Note that in the description here, it is assumed that the flying rock 8 for which the landing point cannot be captured is included (the flying rock 8 that moves outside the shooting range before falling to the ground). FIG. 8 shows an image of the motion of the flying rock 8. As shown in FIG. 8, the trajectory T of the flying rock 8 thrown into the air is a parabola. In FIG. 8, the symbol V indicates the generation point of the flying rock 8 (that is, the tip of the pick), the symbol Q indicates the highest arrival point (that is, the vertex of the parabola) where the flying rock 8 rises highest during the motion, and the symbol R indicates the arrival point where the motion of the flying rock 8 ends. That is, the motion of the flying rock 8 starts at the generation point V, passes through the highest arrival point Q, and ends at the arrival point R. In this embodiment, the flying stone 8's flight distance L (see Fig. 8) is calculated by dividing it into three cases: (1) a case where the flying stone 8 can capture the movement from the generation point V to the arrival point R; (2) a case where the flying stone 8 can capture the movement from the generation point V to the highest arrival point Q; and (3) a case where the flying stone 8 can capture the movement from the generation point V to before the highest arrival point Q (the highest arrival point Q cannot be captured). Note that air resistance is not considered in the movement of the flying stone 8. The case classification is performed, for example, by creating trajectory images Ha, Hb (see Fig. 9) showing the trajectory T of the flying stone 8. The trajectory images Ha, Hb are created, for example, by calculation and drawing processing based on the frame difference composite images Ga, Gb (see Fig. 6). The trajectory image Ha shown in Fig. 9 shows the first viewpoint trajectories T1a, T2a, T3a of three flying stones 8 based on the first viewpoint. Similarly, the trajectory image Hb shows the second viewpoint trajectories T1b, T2b, T3b of three flying stones 8 based on the second viewpoint. The trajectories T1a, T1b are the trajectories showing the movement from the generation point V to the arrival point R. The trajectories T2a, T2b are the trajectories showing the movement from the generation point V to a position slightly past the highest arrival point Q. The trajectories T3a, T3b are the trajectories showing the movement from the generation point V to a position slightly before the highest arrival point Q. Note that the case of the flying stone 8 may be directly determined from the frame difference composite images Ga, Gb. Also, the trajectory images Ha, Hb of the flying stone 8 and the frame difference composite images Ga, Gb may be displayed, and the case of the flying stone 8 may be determined based on the information displayed for humans.

[0018] <Case (1): Processing of the flying stone 8 capable of capturing the movement from the generation point V to the arrival point R> Referring to FIG. 9 (and referring to FIGS. 1 to 8 as appropriate), the processing in case (1) will be described. FIG. 9 is a diagram showing the flow of processing when calculating the flight distance as the motion information. In this case, the flight distance L of the flying rock 8 from the arrival point V is obtained. Specifically, the motion information calculation unit 47 obtains the three-dimensional position coordinates of the generation point V and the arrival point R of the flying rock 8, and calculates the difference as the flight distance L. For example, the motion information calculation unit 47 causes the display unit 41 to display the first viewpoint trajectory T1a of the flying rock 8 based on the first viewpoint, and accepts the input of the position of the tip of the breaker 2a (generation point Va) based on the first viewpoint and the arrival point Ra of the flying rock 8 based on the first viewpoint. Further, the motion information calculation unit 47 causes the display unit 41 to display the second viewpoint trajectory T1b of the flying rock 8 based on the second viewpoint, and accepts the input of the position of the tip of the breaker 2a (generation point Vb) based on the second viewpoint and the arrival point Rb of the flying rock 8 based on the second viewpoint. Next, the motion information calculation unit 47 calculates the three-dimensional coordinates of the generation point V of the trajectory T1 of the flying rock 8 using stereo image analysis from the position information of the generation point Va of the first viewpoint trajectory T1a of the flying rock 8 based on the first viewpoint and the generation point Vb of the second viewpoint trajectory T1b of the flying rock 8 based on the second viewpoint. Similarly, the motion information calculation unit 47 calculates the three-dimensional coordinates of the arrival point R of the trajectory T1 of the flying rock 8 using stereo image analysis from the position information of the arrival point Ra of the first viewpoint trajectory T1a of the flying rock 8 based on the first viewpoint and the arrival point Rb of the second viewpoint trajectory T1b of the flying rock 8 based on the second viewpoint. Then, the motion information calculation unit 47 calculates the difference between the calculated three-dimensional coordinates of the tip of the breaker 2a (that is, the generation point V of the flying rock 8) and the three-dimensional coordinates of the arrival point R of the flying rock 8 as the flight distance L. Note that the three-dimensional coordinates of the tip of the breaker 2a (generation point V) may be registered in advance.

[0019] <Case (2): Processing of the flying rock 8 capable of photographing the motion from the generation point V to the highest arrival point Q> Referring to FIG. 9 (and referring to FIGS. 1 to 8 as appropriate), the processing in the case of the case (2) will be described. In this case, the flying distance L of the flying rock 8 from the highest reaching point Q is obtained. Specifically, the motion information calculation unit 47 obtains the three-dimensional position coordinates of the generation point V and the highest reaching point Q of the flying rock 8, and calculates the flying distance L as twice the horizontal distance to the highest reaching point Q. For example, the motion information calculation unit 47 causes the first viewpoint trajectory T2a of the flying rock 8 based on the first viewpoint to be displayed on the display unit 41, and accepts the input of the position of the tip (generation point Va) of the breaker 2a based on the first viewpoint and the highest reaching point Qa (first vertex) of the flying rock 8 based on the first viewpoint. Further, the motion information calculation unit 47 causes the second viewpoint trajectory T2b of the flying rock 8 based on the second viewpoint to be displayed on the display unit 41, and accepts the input of the position of the tip (generation point Vb) of the breaker 2a based on the second viewpoint and the highest reaching point Qb (second vertex) of the flying rock 8 based on the second viewpoint. Next, the motion information calculation unit 47 calculates the three-dimensional coordinates of the generation point V of the trajectory T2 of the flying rock 8 using stereo image analysis from the position information of the generation point Va of the first viewpoint trajectory T2a of the flying rock 8 based on the first viewpoint and the generation point Vb of the second viewpoint trajectory T2b of the flying rock 8 based on the second viewpoint. Similarly, the motion information calculation unit 47 calculates the three-dimensional coordinates of the highest reaching point Q (the vertex of the parabola) of the trajectory T2 of the flying rock 8 using stereo image analysis from the position information of the highest reaching point Qa (first vertex) of the first viewpoint trajectory T2a of the flying rock 8 based on the first viewpoint and the highest reaching point Qb (second vertex) of the second viewpoint trajectory T2b of the flying rock 8 based on the second viewpoint. Then, the motion information calculation unit 47 calculates the flying distance L as twice the horizontal direction difference distance Lq (see FIG. 8) between the calculated three-dimensional coordinates of the tip of the breaker 2a (that is, the generation point V of the flying rock 8) and the three-dimensional coordinates of the highest reaching point Q of the flying rock 8. Note that the three-dimensional coordinates of the tip (generation point V) of the breaker 2a may be registered in advance. Further, when considering air resistance, the flying distance L may be the product of a coefficient greater than 1 and less than 2 and the distance Lq.

[0020] <Case (3): Processing of the flying rock 8 that can capture the motion from the generation point V to before the highest reaching point Q (the highest reaching point Q cannot be captured)> Referring to FIG. 10 (and referring to FIGS. 1 to 9 as appropriate), the processing in the case of case (3) will be described. FIG. 10 is a diagram showing the flow of processing when calculating the flight distance and kinetic energy as motion information. In this case, the flight distance L of the flying stone 8 is obtained from the speed (horizontal direction, vertical direction) of the flying stone 8. Specifically, the motion information calculation unit 47 obtains the speed (horizontal direction, vertical direction) from the moving distance of the flying stone 8 between certain frames, and calculates the horizontal distance when it falls to the height of the tip (generation point V) of the breaker 2a as the flight distance L. For example, the motion information calculation unit 47 causes the display unit 41 to display the first frame difference composite image Ga based on the first viewpoint, and accepts the input of the first viewpoint position Wa(t) of the flying stone 8 based on the first viewpoint at time t (the Nth frame) and the first viewpoint position Wa(t+α) of the flying stone 8 based on the first viewpoint at time t+α (the N+βth frame). In addition, the motion information calculation unit 47 causes the display unit 41 to display the second frame difference composite image Gb based on the second viewpoint, and accepts the input of the position of the second viewpoint position Wb(t) of the flying stone 8 based on the second viewpoint at time t (the Nth frame) and the second viewpoint position Wb(t+α) of the flying stone 8 based on the second viewpoint at time t+α (the N+βth frame). Next, the motion information calculation unit 47 calculates the three-dimensional coordinates of the position W(t) of the flying stone 8 at time t (the Nth frame) using stereo image analysis from the position information of the first viewpoint position Wa(t) of the flying stone 8 based on the first viewpoint and the second viewpoint position Wb(t) of the flying stone 8 based on the second viewpoint. Similarly, the motion information calculation unit 47 calculates the three-dimensional coordinates of the position W(t+α) of the flying stone 8 at time t+α (the N+βth frame) using stereo image analysis from the position information of the first viewpoint position Wa(t+α) of the flying stone 8 based on the first viewpoint and the second viewpoint position Wb(t+α) of the flying stone 8 based on the second viewpoint. Subsequently, the motion information calculation unit 47 obtains the speed (horizontal direction, vertical direction) of the flying stone 8 from the calculated positions W(t) and W(t+α), and calculates the remaining trajectory that could not be captured from the obtained speed. The motion information calculation unit 47 calculates, for example, the trajectory up to the height of the tip (generation point V) of the breaker 2a as the remaining trajectory. Then, the motion information calculation unit 47 calculates the flight distance L in the same manner as in the case of case (1).That is, the motion information calculation unit 47 calculates the difference between the three-dimensional coordinates of the tip of the breaker 2a (i.e., the occurrence point V of the flying rock 8) and the three-dimensional coordinates of the end point of the calculated remaining trajectory (corresponding to the arrival point R) as the flying distance L. Note that the first-viewpoint velocity of the flying rock 8 based on the first viewpoint and the second-viewpoint velocity of the flying rock 8 based on the second viewpoint may be obtained respectively, and the velocity (horizontal direction, vertical direction) on the three-dimensional coordinates of the flying rock 8 may be obtained by synthesizing them.

[0021] [Analysis other than the flying distance] Next, with reference to FIG. 10, the case of obtaining the kinetic energy as the motion information of the flying rock 8 will be described. The kinetic energy of the flying rock 8 can be calculated if the mass and velocity of the flying rock 8 are known. The velocity of the flying rock 8 can be obtained, for example, by the method described in case (3) in the calculation of the flying distance L. That is, the velocity of the flying rock 8 can be obtained by tracing the coordinates of a specific flying rock 8 captured in the same frame numbers of the left and right cameras 31 and 32. Therefore, below, the calculation of the mass of the flying rock 8 will be described. The mass of the flying rock 8 is obtained, for example, from the density and size of the flying rock 8. The density of the flying rock 8 is specified by investigating the type of the object to be crushed (rock type if the object is a rock mass). The calculation of the size of the flying rock 8 will be described with reference to FIG. 11. FIG. 11 is a diagram for explaining the method of calculating the size of the flying rock 8. (a) is an example of the frame difference composite image G, (b) is an enlarged view of the trajectory portion (region K1) captured in the frame difference composite image G, and (c) is an enlarged view of the flying rock portion (region K2). The size of the flying rock 8 is estimated, for example, from the flying rock 8 shown in either the left or right frame difference composite image G (both may be used). As shown in FIG. 11(b), the apparent size of the flying rock 8 varies depending on the shape of the flying rock 8 and the timing of shooting. Therefore, in this embodiment, as shown in FIG. 11(c), the particle size of the flying rock 8 is defined from the pixel size in the longitudinal direction when the flying rock 8 appears relatively large. Note that the method for specifying the size of the flying rock 8 is not limited to that described here. As a result, the kinetic energy of the flying rock 8 can be obtained from the velocity, size, and density (estimated from the on-site geology) of the flying rock 8. Note that the kinetic energy of the flying rock 8 can be obtained in the same manner even in cases (1) and (2).

[0022] [Display of Analysis Results of Flying Rocks] Next, with reference to FIG. 12 (and FIGS. 1 to 11 as appropriate), the display of the analysis results of the flying rock 8 will be described. FIG. 12 is an example of the analysis results of the flying rock 8. (a) shows the reaching points of the flying rock 8 on the horizontal plane (plan view), and (b) shows the highest reaching point and trajectory of the flying rock 8 (side view). As shown in FIG. 12(a), by drawing the reaching points R of the flying rock 8 on the horizontal plane, the flying rock 8 that spreads radially in multiple directions from the occurrence point V can be confirmed. Therefore, the influence exerted by the flying rock 8 on the surroundings can be grasped at a glance. Also, as shown in FIG. 12(b), by drawing the trajectory T of the flying rock 8 on the vertical plane, the flying rock 8 that flies in a parabolic shape from the occurrence point V can be confirmed. Therefore, the relationship between the flying distance and height of the flying rock 8 can be grasped at a glance, and the conditions for installing the protective fence and the effects when installed can be known. In particular, there are work sites with various terrains and surrounding environments, and crushing operations may be carried out near existing facilities and structures. As shown in FIG. 12(b), assume a case where a crushing operation is carried out near the in-service road 9b, and the work area 9a is located at a higher position than the in-service road 9b. In this case, measures such as installing the protective fence 7 so that the flying rock 8 does not reach the in-service road 9b are necessary. However, due to the particularity of the terrain at the work site, it is not easy to judge only by experience the influence exerted by the flying rock 8 on the in-service road 9b compared to the case where the work area 9a and the in-service road 9b are on the same plane. In that regard, as shown in FIG. 12(b), by drawing the trajectory T of the flying rock 8 and the protective fence 7 on the vertical plane, the effect of the protective fence 7 can be known at a glance. In FIG. 12(b), it can be seen that even when the protective fence 7 with the height shown in the figure is installed, the flying rock 8 will reach the in-service road 9b. Note that other information (such as particle size, mass, velocity, kinetic energy, etc.) may be associated and displayed with the information on the reaching points R of the flying rock 8 and the trajectory T of the flying rock 8 shown in FIG. 12.

[0023] As described above, according to the flying rock analysis system 1 according to the embodiment, by analyzing the captured image E captured by the stereo camera, it is possible to detect the movement (position, speed, energy, etc.) of the flying rocks 8 scattered in various directions (particularly, the optical axis direction of the camera). When shooting is performed with a monocular camera, since the flying rocks 8 spread radially in multiple directions, it is difficult to accurately detect the movement in the optical axis direction of the camera. As described above, the embodiments of the present invention have been described, but the present invention is not limited thereto, and can be implemented without changing the gist of the claims.

Explanation of Signs

[0024] 1 Flying rock analysis system 2 Construction machine (crusher) 2a Breaker 3 Shooting unit 31 First camera 32 Second camera 33 Connecting part 34 Tripod 4 Processing unit 41 Display unit 42 Input unit 43 Communication unit 44 Storage unit 45 Control unit 46 Difference image creation unit 47 Motion information calculation unit 7 Protective fence 8 Flying rock 9 Rock mass (object to be crushed) E Captured image F Frame difference image G Frame difference composite image H Trajectory image T Trajectory

Claims

1. A flying rock analysis system for analyzing the scattering situation of flying rocks generated by the crushing operation of a crusher, a photographing unit that photographs a range including the generation point of the flying rock, and a processing unit as a computer that obtains motion information regarding the motion of the flying rock by the frame difference method, wherein the photographing unit is a stereo camera, the processing unit calculates the motion information from a first photographed image by a first camera and a second photographed image by a second camera, a difference image creation unit that creates a first frame difference image that is a difference between the first photographed images continuous in time series and creates a second frame difference image that is a difference between the second photographed images continuous in time series, and a motion information calculation unit that calculates the position of the flying rock by stereo analysis based on the first frame difference image and the second frame difference image, and calculates the arrival point of the flying rock based on the calculated position of the flying rock, the motion information calculation unit causes the display unit to display a first viewpoint trajectory of the flying rock based on the first camera, receives input of position information of a first vertex via an input unit, causes the display unit to display a second viewpoint trajectory of the flying rock based on the second camera, receives input of position information of a second vertex via the input unit, and calculates the arrival point from the relationship between the input first vertex and second vertex and the generation point, A flying rock analysis system characterized by the above.

2. A flying rock analysis system for analyzing the scattering situation of flying rocks generated by the crushing operation of a crusher, a photographing unit that photographs a range including the generation point of the flying rock, and a processing unit as a computer that obtains motion information regarding the motion of the flying rock by the frame difference method, wherein the photographing unit is a stereo camera, the processing unit calculates the motion information from a first photographed image by a first camera and a second photographed image by a second camera, A differential image creation unit that creates a first frame difference image that is the difference between the first captured images consecutive in time series, and creates a second frame difference image that is the difference between the second captured images consecutive in time series, A motion information calculation unit that calculates the position of the flying rock by stereo analysis based on the first frame difference image and the second frame difference image, and calculates the arrival point of the flying rock based on the calculated position of the flying rock, The motion information calculation unit causes the display unit to display the first viewpoint positions consecutive in time series of the flying rock based on the first camera, accepts input of position information at a plurality of time points via the input unit, and causes the display unit to display the second viewpoint positions consecutive in time series of the flying rock based on the second camera, accepts input of position information at a plurality of time points via the input unit, and calculates the arrival point from the relationship between the input first viewpoint position, the second viewpoint position, and the generation point. A flying rock analysis system characterized by the above.

3. The motion information calculation unit further obtains the kinetic energy of the flying rock using information regarding the type of the object to be crushed. The flying rock analysis system according to claim 1 or claim 2, characterized by the above.

4. A flying rock analysis method for analyzing the scattering state of flying rocks generated by a crushing operation of a crusher, A photographing step of photographing a range including the generation point of the flying rock, A processing step in which a computer obtains motion information regarding the motion of the flying rock by the frame difference method, In the photographing step, photographing is performed by a stereo camera. In the processing step, the motion information is calculated from a first captured image by a first camera and a second captured image by a second camera. A differential image creation step of creating a first frame difference image that is the difference between the first captured images consecutive in time series, and creating a second frame difference image that is the difference between the second captured images consecutive in time series. A motion information calculation step of calculating the position of the flying rock by stereo analysis based on the first frame difference image and the second frame difference image, and calculating the arrival point of the flying rock based on the calculated position of the flying rock is performed. In the motion information calculation step, the first viewpoint trajectory of the flying rock based on the first camera is displayed on the display unit, and the input of the position information of the first vertex is received via the input unit. At the same time, the second viewpoint trajectory of the flying rock based on the second camera is displayed on the display unit, and the input of the position information of the second vertex is received via the input unit. The arrival point is calculated from the relationship between the input first vertex, the second vertex, and the generation point. A flying rock analysis method characterized by the above.

5. A flying rock analysis method for analyzing the scattering state of flying rocks generated by a crushing operation of a crusher, A photographing step of photographing a range including the generation point of the flying rock, A processing step in which a computer obtains motion information regarding the motion of the flying rock by the frame difference method, In the photographing step, photographing is performed by a stereo camera. The processing step calculates the motion information from the first photographed image by the first camera and the second photographed image by the second camera. A difference image creation step of creating a first frame difference image that is the difference between the first photographed images continuous in time series, and creating a second frame difference image that is the difference between the second photographed images continuous in time series. A motion information calculation step of calculating the position of the flying rock by stereo analysis based on the first frame difference image and the second frame difference image, and calculating the arrival point of the flying rock based on the calculated position of the flying rock is performed. In the movement information calculation step, the first viewpoint positions of the flying stones in the time series based on the first camera are displayed on the display unit, and the input of position information at a plurality of time points is received via the input unit. At the same time, the second viewpoint positions of the flying stones in the time series based on the second camera are displayed on the display unit, and the input of position information at a plurality of time points is received via the input unit. The arrival point is calculated from the relationship between the input first viewpoint position, the second viewpoint position, and the generation point. A flying stone analysis method characterized by the above.

Images