Inspection equipment

Abstract

To provide a technique that can appropriately inspect a conveyance path including a plurality of conveyor rollers.SOLUTION: An inspection device 10 comprises: a conveyance body 11 that can be conveyed by a conveyance path 1 including a plurality of conveyor rollers 2; and a camera 12 that is installed on the conveyance body 11, and while being conveyed by the conveyance path 1, photographs the plurality of conveyor rollers 2 so that the advance distance of the conveyance path 1 per one frame becomes equal to or less than the array pitch of the plurality of conveyor rollers 2.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This disclosure relates to a technology for inspecting a transport path that includes multiple conveyor rollers. [Background technology]

[0002] Patent Document 1 discloses a technology for inspecting a transport path by transporting a housing equipped with a camera or the like along the transport path. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Patent No. 6446116 [Overview of the project] [Problems that the invention aims to solve]

[0004] However, depending on the characteristics of the camera, it may not be possible to properly photograph the conveyor rollers that make up the transport path. Therefore, one of the purposes of this disclosure is to provide a technology that can properly inspect a transport path that includes multiple conveyor rollers. [Means for solving the problem]

[0005] An inspection apparatus according to one embodiment of the present disclosure comprises a conveyor that can be transported by a transport path including a plurality of conveyor rollers, and a camera installed on the conveyor that, while being transported by the transport path, photographs the plurality of conveyor rollers such that the distance traveled by the transport path per frame is less than or equal to the arrangement pitch of the plurality of conveyor rollers. [Effects of the Invention]

[0006] According to the technology disclosed herein, a conveying path including multiple conveyor rollers can be properly inspected. [Brief explanation of the drawing]

[0007] [Figure 1] Figure 1 is a schematic perspective view showing the external appearance of an inspection device 10 according to one embodiment of the present disclosure. [Figure 2] Figure 2 shows an example of an image captured by camera 12. [Figure 3] Figure 3 is a schematic diagram illustrating the positional relationship between the inspection device 10 and the conveyor roller 2. [Figure 4] Figure 4 is a schematic diagram illustrating the positional relationship between the inspection device 10 and the conveyor roller 2. [Figure 5] Figure 5 shows the range of mounting positions and mounting angles for camera 12 that yield N≧1. [Figure 6] Figure 6 is a schematic diagram illustrating the blind spots created by the two conveyor rollers 2c and 2d. [Figure 7] Figure 7 is a schematic diagram illustrating the blind spots created by the two conveyor rollers 2c and 2d. [Figure 8] Figure 8 is a schematic diagram illustrating the tangent line S5 common to conveyor rollers 2c and 2d. [Figure 9] Figure 9 is a schematic diagram illustrating the relationship between angles θx, θy and the blind spot created by the conveyor roller 2c. [Figure 10] Figure 10 shows the range of mounting positions and mounting angles for the camera 12 to obtain N≧1 without the conveyor roller 2d entering a blind spot. [Modes for carrying out the invention]

[0008] The embodiments of this disclosure will be described in detail below with reference to the attached drawings.

[0009] Figure 1 is a schematic perspective view showing the external appearance of an inspection device 10 according to one embodiment of the present disclosure.

[0010] An inspection device 10 according to an embodiment of the present disclosure detects an abnormality in a conveyance path 1 including a plurality of conveying rollers 2. As shown in FIG. 1, the inspection device 10 includes a conveyance body 11 that can be conveyed by the conveyance path 1, a camera 12 installed on the conveyance body 11, and a control device 13. The conveying roller 2 is, for example, a rotating roller that can be rotated by a built-in driving device (as an example, a motor or the like). By rotating each conveying roller 2 in one direction, the luggage container on the conveyance path 1 is conveyed in the +x direction. However, some of the conveying rollers 2 may be idle rollers that can rotate freely without a driving device. Both ends in the axial direction of the conveying roller 2 are supported by a frame 3.

[0011] While being conveyed by the conveyance path 1 in the same manner as the luggage container, the inspection device 10 photographs the conveying roller 2 with the camera 12. In the case of the specific example shown in FIG. 1, the conveyance body 11 is, for example, in the shape of a container, and the control device 13 is housed inside it. The camera 12 is attached in front of the conveyance body 11 in the conveyance direction of the conveyance body 11, and photographs the conveying roller 2 located in the conveyance direction of the conveyance body 11. The control device 13 may perform operations such as saving the image photographed by the camera 12, image processing, abnormality diagnosis, and data communication to the outside. Note that the specific form of the inspection device 10 is not limited to the container shape as illustrated in FIG. 1, and a form that can be conveyed in the conveyance path 1 may be appropriately selected.

[0012] FIG. 2 is an example of an image photographed by the camera 12.

[0013] [[ID=eleven]] Since the camera 12 is attached in front of the conveyance body 11, as shown in FIG. 2, one or two or more conveying rollers 2 located in the conveyance direction are reflected in the image photographed by the camera 12.

[0014] Camera 12 may be capable of continuously shooting video, or it may be capable of continuously shooting still images at specific time intervals. Camera 12 may be, for example, an imaging device capable of capturing visible light images of the object being photographed, or an imaging device capable of capturing invisible light images of the object being photographed (e.g., infrared images, ultraviolet images, etc.). Furthermore, Camera 12 may be an imaging device (such as a thermographic camera) capable of visualizing the temperature (including temperature distribution, etc.) of the object being photographed.

[0015] In either case, one or more conveyor rollers 2 are captured in each frame (image captured by camera 12). Here, camera 12 captures multiple conveyor rollers 2 while the conveyed object 11 is being transported along the transport path 1, such that the distance traveled by the conveyed object 11 per frame is less than or equal to the arrangement pitch of the multiple conveyor rollers 2. As a result, each conveyor roller 2 is captured in at least one frame, so there is no chance of missing any conveyor rollers 2 from being captured.

[0016] The following describes the shooting conditions, which include parameters such as the frame rate, field of view, mounting position and angle of the camera 12 on the transporter 11, the transport speed of the transport path 1, and the diameter and arrangement pitch of the conveyor rollers 2.

[0017] Figure 3 is a schematic diagram illustrating the positional relationship between the inspection device 10 and the conveyor roller 2.

[0018] Figure 3 shows the inspection device 10 placed on the conveying surface 4 of the conveying path 1. The conveying surface 4 may be, for example, a virtual plane connecting the contact points between the conveyor roller 2 and the conveyed object. The origin O (x=0, y=0) may be set, for example, on the conveying surface 4, below the lens of the camera 12 (for example, directly below the center of the lens). For convenience, the direction y>0 will be described as the upward direction and x>0 as the forward direction.

[0019] The y-coordinate of the conveying surface 4 is y=0, and the bottom surface of the conveying body 11 and the top surface of the conveyor roller 2 are in contact with the conveying surface 4. At time T1, a certain conveyor roller 2a is at relative position A, and at time T2, the same conveyor roller 2a is at relative position B. In other words, between time T1 and time T2, the conveying body 11 is conveyed in the direction x>0. Thus, Figure 3 schematically shows the positional relationship between the inspection device 10 and the conveyor roller 2a at time T1 and the positional relationship between the inspection device 10 and the conveyor roller 2a at time T2 in a single diagram. The distance between relative position A and relative position B is L. Therefore, between time T1 and time T2, the relative distance of the conveyor roller 2a as seen from the inspection device 10 changes by L. In the example shown in Figure 3, the conveyor roller 2a located at relative position A is captured on the upper edge of the image, and the conveyor roller 2a located at relative position B is captured on the lower edge of the image.

[0020] Variables related to camera 12 include, for example, the field of view θang [rad] of camera 12, the mounting angle θasm [rad] of camera 12, the frame rate f [frame / sec] representing the number of shots taken per unit time by camera 12, and the distance h [m] between camera 12 and the conveying surface 4 of conveying path 1. For the mounting angle θasm, the x-direction is used as the reference, and counterclockwise rotation is considered positive. Variables related to conveying path 1 include, for example, the conveying speed v [m / sec] of conveying path 1 and the diameter φ [m] of conveying roller 2.

[0021] Here, as shown in Figure 3, let S0 be a reference line parallel to the conveying surface 4 of the conveying path 1, extending in the x-direction which is the conveying direction of the conveyed body 11 through the camera 12, let S2 be a tangent line passing through the camera 12 and touching the conveyor roller 2a at relative position A on the side closer to the conveying surface 4, let S1 be a tangent line passing through the camera 12 and touching the conveyor roller 2a at relative position B on the side farther from the conveying surface 4, and let S3 be the center line of the field of view. Then the angle θα indicating the upper end of the field of view and the angle θβ indicating the lower end of the field of view are: θα = θasm + θang / 2 θβ = θasm - θang / 2 It can be expressed as follows.

[0022] As shown in Figure 4, if at time T2 the next conveyor roller 2b adjacent to conveyor roller 2a is at relative position A, then both conveyor rollers 2a and 2b will be captured in the frame taken by camera 12 at time T2. This means that if the travel distance of the conveyor 11 per frame of camera 12 is less than or equal to the arrangement pitch of the multiple conveyor rollers 2, then at least a part of each conveyor roller 2 will be captured in one of the frames. To explain more specifically, if the distance between relative positions A and B is L, the conveying speed is v, and the frame rate is f, then the number of times camera 12 captures one conveyor roller 2 N is: N = f·L / v This can be expressed as follows. Therefore, if N is 1 or greater, each conveyor roller 2 will be reflected in one of the frames.

[0023] The following explains in detail how to calculate the value of N.

[0024] First, as shown in Figure 3, when a certain conveyor roller 2 moves out of the shooting area of ​​camera 12 (when the conveyor roller 2 is at relative position B), the center coordinates are (x r1 ,y r1 Let (x) be the center coordinate when a certain conveyor roller 2 enters the shooting area of ​​camera 12 (when the conveyor roller 2 is at relative position A). r2 ,y r2 Let's assume that the center of the conveyor roller 2 is located below the conveying surface 4 where y=0, and the surface of the conveyor roller 2 is in contact with the conveying surface 4. y r1 =y r2 = -φ / 2 This is the result.

[0025] Next, x r1 We will find the tangent line S1 is y = mx + h, where m = tanθβ Since it can be expressed as follows, the following equation (1) holds true.

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[0026] Here, when \(0 > \theta_{\beta}>-\frac{\pi}{2}\), that is, when \(m < 0\),

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[0027] On the other hand, when \(-\frac{\pi}{2}>\theta_{\beta}\), that is, when \(m > 0\),

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[0028] Based on the above, the center coordinates of the conveyor roller 2 located at relative position B are:

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[0029] Next, x r2 We will find the tangent line S2 is y = lx + h, where l = tanθα Since it can be expressed as follows, the following equation (2) holds true.

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[0030] Here, if 0 > θα > -π / 2, that is, l < 0,

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[0031] On the other hand, if -π / 2 > θα, that is, if l > 0,

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[0032] Based on the above, the center coordinates of the conveyor roller 2 located at relative position A are:

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[0033] Next, we derive the distance L shown in Figure 3. The distance L is,

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[0034] Figure 5 shows the range of mounting positions and mounting angles for the camera 12 that yield N≧1, where (a) to (d) differ from each other in terms of conveying speed v or conveyor roller diameter φ.

[0035] In Figure 5, N≧1 is obtained in the hatched region. That is, by setting the field of view θang and mounting angle θasm of camera 12 to the hatched region, each conveyor roller 2 can be photographed at least once by camera 12. As shown in Figure 5, the range of field of view θang and mounting angle θasm in which N≧1 is obtained varies depending on various conditions.

[0036] Next, we determine the conditions under which the two conveyor rollers 2 do not overlap in the captured image.

[0037] Figure 6 is a schematic diagram illustrating the blind spots created by the two conveyor rollers 2c and 2d.

[0038] The conveyor rollers 2c and 2d are adjacent in the conveying direction, and both conveyor rollers 2c and 2d are captured in the image taken by the camera 12. In Figure 6, conveyor roller 2d is at relative position A, and conveyor roller 2c is at relative position C. Relative position C is located closer to relative position A than relative position B shown in Figures 3 and 4. The hatched area in Figure 6 is the blind spot created by the conveyor rollers 2c and 2d.

[0039] Here, if another conveyor roller 2 enters a blind spot created by a certain conveyor roller 2, the conveyor roller 2 entering the blind spot is located further away from camera 12 than the conveyor roller that created the blind spot. Also, if the distance between the conveyor roller 2 and camera 12 is large, the blind spot will affect a wider area. For example, conveyor roller 2d may create a wider blind spot than conveyor roller 2c. Furthermore, the narrower the arrangement pitch of the conveyor rollers 2, the more likely it is that other conveyor rollers will enter the resulting blind spot.

[0040] Based on the above, the boundary condition under which the conveyor roller 2d does not enter the blind spot of the conveyor roller 2c in front of it when photographed by the camera 12 is as shown in Figure 7. This means, for example, that the conveyor roller 2d that is relatively far from the camera 12 is in contact with the tangent line S2, and that the conveyor roller 2d that is relatively far from the camera 12 and the conveyor roller 2c in front of it share a common tangent line. Note that the conveyor roller 2d that is relatively far from the camera 12 may be, for example, the conveyor roller 2 that is located at the furthest position from the camera 12 within the range (angle of view) that the camera 12 can photograph.

[0041] When the conveyor roller 2d, which is relatively far from the camera 12, is in contact with the tangent line S2, the condition under which the conveyor roller 2d does not enter the blind spot created by the conveyor roller 2c can be calculated based on the angle θx (see Figure 6) formed by the tangent line S4, which passes through the camera 12 and is in contact with the conveyor roller 2d on the side far from the conveying surface 4, and the reference line S0, and the angle θy (see Figure 8) formed by the tangent line S5, which is in common contact with the side of the conveyor roller 2c that is close to the conveying surface 4 and the side of the conveyor roller 2d that is far from the conveying surface 4, and the reference line S0.

[0042] First, we find the angle θx. As shown in Figure 6, if we let θγ be the angle between the line S6 passing through camera 12 and the center of conveyor roller 2d and the reference line S0, then the angle θγ is:

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[0043] Next, we determine the angle θy. As shown in Figure 8, when the arrangement pitch of the conveyor rollers 2 is p, the angle θy formed by the tangent line S5, which is in common to the conveyor rollers 2c and 2d, and the reference line S0 is:

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[0044] Next, we determine the conditions under which the conveyor roller 2d does not enter the blind spot created by the conveyor roller 2c. As shown in Figure 9, if the relationship between angles θx and θy is θx < θy, the conveyor roller 2d does not enter the blind spot, and if θx > θy, the conveyor roller 2d enters the blind spot. In other words, θx = θy is the boundary condition for whether or not the conveyor roller 2d enters the blind spot. Therefore, by setting the mounting position and mounting angle of the camera 12 so that θx ≤ θy according to the diameter and arrangement pitch of the conveyor roller 2, the conveyor roller 2d will not enter the blind spot created by the conveyor roller 2c.

[0045] Figure 10 shows the range of mounting positions and mounting angles for the camera 12 to obtain N≧1 without the conveyor roller 2d entering a blind spot, with (a) to (d) differing from each other in terms of conveying speed v or conveyor roller diameter φ.

[0046] In Figure 10, within the hatched area, N≧1 can be obtained without the conveyor roller 2d entering a blind spot. In other words, by setting the field of view θang and mounting angle θasm of camera 12 to the hatched area, each conveyor roller 2 can be photographed at least once by camera 12, and the conveyor roller 2d will not enter the blind spot created by the conveyor roller 2c. As shown in Figure 10, the range of field of view θang and mounting angle θasm in which N≧1 can be obtained without the conveyor roller 2d entering a blind spot varies depending on various conditions.

[0047] While embodiments of this disclosure have been described above, it goes without saying that this disclosure is not limited to the embodiments described above, and various modifications are possible without departing from the spirit of this disclosure, and these modifications are also included within the scope of this disclosure. Furthermore, combinations of the embodiments exemplified above are also included within the scope of this disclosure.

[0048] The technology relating to this disclosure includes, but is not limited to, the following configuration examples.

[0049] The inspection device according to this disclosure comprises a conveyor that can be transported by a transport path including multiple conveyor rollers, and a camera installed on the conveyor that photographs the multiple conveyor rollers while being transported by the transport path, such that the distance traveled by the transport path per frame is less than or equal to the arrangement pitch of the multiple conveyor rollers. This makes it possible to properly inspect a transport path including multiple conveyor rollers.

[0050] The camera may be installed within a range of mounting positions and angles that allows each of the multiple conveyor rollers to be photographed at least once as the conveyed object is transported along the conveyor path, based at least on the frame rate (representing the number of images taken per unit time), the field of view, and the transport speed of the conveyor path. This allows the camera's mounting position and angle to be determined according to the camera's characteristics and the transport speed.

[0051] The camera may be installed within a range of mounting positions and angles such that the first conveyor roller, which is included in the area that can be photographed by the camera, and the second conveyor roller, which is adjacent to the first conveyor roller and located closer to the conveyor than the first conveyor roller in the conveying direction of the conveyed object, do not overlap in the captured image. This allows the entire first conveyor roller to be photographed.

[0052] The first conveyor roller may be the one located furthest from the conveyor in the direction of transport of the conveyed object, within the area that can be photographed by the camera. This ensures that none of the conveyor rollers being photographed fall into a blind spot.

[0053] If the camera's field of view is θang [rad], the camera's mounting angle is θasm [rad], the camera's frame rate is f [frames / sec], the distance between the camera and the conveying surface of the conveyor path is h [m], the conveying speed of the conveyor path is v [m / sec], and the diameter of the conveyor roller is φ [m], then the following equation

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[0054] The value of θα may be greater than -π / 2[rad] and less than 0[rad], and the value of θβ may be greater than -π / 2[rad] and less than 0[rad], or the value of θα may be greater than -π / 2[rad] and less than 0[rad], and the value of θβ may be less than -π / 2[rad]. According to this, the conveyor roller can be properly photographed by the camera.

[0055] Assuming a reference line parallel to the conveying surface of the conveying path and extending in the conveying direction of the conveyed object through the camera, a first tangent line passing through the camera and touching the first conveyor roller among multiple conveyor rollers on the side furthest from the conveying surface, and a second tangent line commonly touching the side of the second conveyor roller closer to the conveying surface and the side of the first conveyor roller furthest from the conveying surface, and with the pitch between the first and second conveyor rollers being p, the angle θx between the first tangent line and the reference line and the angle θy between the second tangent line and the reference line are given by the following equations

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[0056] Assuming a straight line passing through the camera and the center of the rotation axis of the first conveyor roller, and if the angle between this line and the reference line is θγ, then the angle θx is given by the following equation.

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[0057] 1. Conveyor path 2,2a,2b,2c,2d Conveyor Rollers 3 frames 4 Conveying surface 10 Inspection equipment 11. Carrier 12 cameras 13 Control device A~C Relative position S0 reference line S1~S5 Tangent line S6 straight line θang field of view θasm mounting angle

Claims

1. A conveying body that can be transported by a conveying path including multiple conveyor rollers, An inspection device comprising: a camera installed on the conveyor body, which, while being conveyed along the conveyor path, photographs the plurality of conveyor rollers such that the distance the conveyor body travels per frame is less than or equal to the arrangement pitch of the plurality of conveyor rollers.

2. The inspection apparatus according to claim 1, wherein the camera is installed within a range of mounting positions and mounting angles that allows each of the plurality of conveyor rollers to be photographed at least once when the conveyed object is being transported along the conveyor path, based at least on a frame rate representing the number of times that can be photographed per unit time, a field of view, and the transport speed of the transport path.

3. The aforementioned camera, Of the plurality of conveyor rollers, the first conveyor roller included in the area that can be photographed by the camera, The inspection apparatus according to claim 2, wherein the second conveyor roller, which is adjacent to the first conveyor roller and located closer to the conveyor than the first conveyor roller in the conveying direction of the conveyed body, is installed within a range of mounting positions and mounting angles such that they do not overlap in the captured image.

4. The first conveyor roller is located in the area that can be photographed by the camera, at the position furthest from the conveyor in the conveying direction of the conveyor, The inspection apparatus according to claim 3.

5. If the field of view of the camera is θang [rad], the mounting angle of the camera is θasm [rad], the frame rate of the camera is f [frame / sec], the distance between the camera and the conveying surface of the conveying path is h [m], the conveying speed of the conveying path is v [m / sec], the distance between the positions of two adjacent conveyor rollers is L [m], and the diameter of the conveyor roller is φ [m], then the following equation [Math 1] The inspection apparatus according to claim 1, wherein the value of N represented by is 1 or greater.

6. The inspection apparatus according to claim 5, wherein the value of θα is greater than -π / 2 [rad] and less than 0 [rad], and the value of θβ is greater than -π / 2 [rad] and less than 0 [rad].

7. The inspection apparatus according to claim 5, wherein the value of θα is greater than -π / 2 [rad] and less than 0 [rad], and the value of θβ is less than -π / 2 [rad].

8. A reference line parallel to the transport surface of the transport path and extending through the camera in the transport direction of the transported body, The first tangent line, passing through the camera, is in contact with the first conveyor roller among the plurality of conveyor rollers on the side furthest from the conveying surface, Assuming a second tangent line that is in common with the side of the second conveyor roller that is positioned adjacent to the first conveyor roller in the conveying direction of the conveyed body, closer to the conveying surface, and with the side of the first conveyor roller that is farther from the conveying surface, If the pitch between the first conveyor roller and the second conveyor roller is p, The angle θx between the first tangent line and the reference line, and the angle θy between the second tangent line and the reference line are given by the following equation [Math 2] An inspection apparatus according to any one of claims 5 to 7, satisfying the requirements of the claim.

9. Assuming a straight line passing through the camera and the center of the rotation axis of the first conveyor roller, If the angle between the aforementioned straight line and the aforementioned reference line is denoted as θγ, The aforementioned angle θx is given by the following equation [Math 3] The inspection apparatus according to claim 8, as represented by [the specified method].

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