Inspection method

Abstract

To efficiently execute an inspection while improving determination accuracy.SOLUTION: An inspection device comprises: imaging means 11 which images the assembling state; specification means 12 which specifies the position and size of each of a clip 23 and a bracket 22 (refer to Fig.2) from an acquired image acquired by the imaging means 11; arithmetic means 13 which associates the length of a real space with a pixel in the acquired image by using the size in the acquired image and the position of each of the clip 23 and the bracket 22 specified by the specification means 12 and the previously-acquired sizes in the real space of the clip 23 and the bracket 22; and determination means 14 which determines the quality of the assembling state by using the length in the real space of an inspection object portion calculated from the size in the acquired image with association.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for inspecting a clip that joins a hose and a bracket. [Background technology]

[0002] In recent years, vehicles have been using hoses and brackets to carry engine coolant and fuel. Typically, clips are used to attach the hoses to the brackets. After the hoses and brackets are assembled, an inspection is conducted to determine whether the clips are properly attached.

[0003] Patent Document 1 describes an inspection method in which an image of an inspection location is acquired by an imaging means and whether or not the inspection location is normal is determined. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-082928 Summary of the Invention [Problem to be solved by the invention]

[0005] The inspection method disclosed in Patent Document 1 can obtain the number of pixels of an object captured by an imaging device, but has the problem that this number of pixels cannot be compared with the actual dimensions. As a result, there are cases where the accuracy of judgment cannot be guaranteed depending on the inspection item.

[0006] On the other hand, if the inspection of whether the assembly state using the hose, bracket, and clip is normal is performed by a human visual inspection, the inspection time becomes long, which causes a problem of reduced productivity. The present invention provides an inspection method that improves the accuracy of determination and performs inspection efficiently. [Means for solving the problem]

[0007] The inspection method of the present invention is an inspection method for inspecting the assembly state of a hose, a bracket, and a clip joining the hose and the bracket, wherein an imaging means images the assembly state, an identification means identifies the respective positions and sizes of the clip and the bracket from the acquired image acquired by the imaging means, a calculation means associates the respective positions of the clip and the bracket and their respective sizes in the acquired image identified by the identification means with the sizes of the clip and the bracket in real space that were acquired in advance, and a determination means determines whether the assembly state is good or bad using the length in real space of the part to be inspected calculated from the size in the acquired image based on the association. This allows automatic pass / fail judgment to be made while associating the pixels in the acquired image with the size of the object to be inspected. [Effects of the Invention]

[0008] This allows for efficient testing while improving the accuracy of the determination. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram illustrating a configuration of an inspection device and an object to be inspected. [Figure 2] FIG. 10 is a diagram showing an example of an assembled state of a hose, a bracket, and a clip. [Figure 3] 1 is a cross-sectional view showing an object to be inspected along a vertical direction. [Figure 4] FIG. 2 is a front view of the appearance of the inspection object. [Figure 5] FIG. 10 is a horizontal cross-sectional view of the location where the clip is provided. [Figure 6] FIG. 1 is a diagram showing first to fifth inspection items, an example of a standard, and an example of a defect that occurs when the standard is not met. [Figure 7]10 is a flowchart showing a procedure for inspecting a second inspection item. [Figure 8] 10A and 10B are diagrams showing an example of the number of pixels in the acquired image of a bracket and a clip and their sizes in real space. [Figure 9] FIG. 10 is a diagram showing an example of the ratio of the distance of the bracket to the distance of the clip to the inspection target location. [Figure 10] 10 is a flowchart showing a procedure for inspecting a fourth inspection item. [Figure 11] FIG. 10 is a perspective view showing the positions of the claws and oval portions of the clip. [Figure 12] FIG. 10 is a diagram illustrating calculation of an elliptical shape in an elliptical portion. [Figure 13] FIG. 10 is a diagram showing a state in which the angle of the claw portion is calculated assuming that the claw of the clip is on an ellipse. [Figure 14] 10A and 10B are diagrams illustrating calculation of the angle of the claw portion. [Figure 15] 10 is a flowchart showing a procedure for inspecting a first inspection item. [Figure 16] 10A and 10B are diagrams showing the arc shapes of the hose and the bracket and the locations where the positional relationship between them is acquired. [Figure 17] FIG. 10 is a diagram showing a state in which an inspection object is placed obliquely in an acquired image. [Figure 18] FIG. 10 is a diagram showing a state in which the first center coordinates and the second center coordinates are connected by a straight line. [Figure 19] FIG. 10 is a diagram showing a state in which a processed image is created from an acquired image by projective transformation. DETAILED DESCRIPTION OF THE INVENTION

[0010] Embodiment 1 An inspection device and an inspection object according to an embodiment of the present invention will be described below with reference to the drawings. Fig. 1 shows an inspection device 1 and a vehicle 2 that is the inspection object. Here, a hose 21, a bracket 22, and a clip 23 (see Fig. 2) that joins the hose 21 and the bracket 22, which are the inspection objects, are assembled to the vehicle 2. Furthermore, the bracket 22 has a circular bottom 22a in a top view and an upward protruding portion 22b (see Fig. 3).

[0011] The inspection device 1 comprises an imaging means 11 that photographs the state in which each of the inspection objects is assembled to the vehicle 2, an identification means 12 that identifies the positions and sizes of each of the brackets 22 and clips 23 from the images acquired by the imaging means 11, a calculation means 13, and a judgment means 14 that judges whether the brackets 22 and clips 23 are good or bad based on the positions and sizes of each of the brackets 22 and clips 23.

[0012] In the following, the horizontal direction of the real space may be referred to as the width direction or the left-right direction, and the height direction perpendicular to the horizontal direction may be referred to as the up-down direction. Also, for an image acquired by the imaging means 11, the left-right direction on the image may be referred to as the width, and the up-down direction on the image may be referred to as the height.

[0013] As shown in Fig. 1, a camera can be used as the imaging means 11. Furthermore, a computer 3 in which a main memory device, an auxiliary memory device, an arithmetic unit, etc. work together can be used as the identification means 12 and the determination means 14. This computer can realize the functions of the identification means 12, the arithmetic unit 13, and the determination means 14 by executing a predetermined program.

[0014] The camera used as the imaging means 11 can be an industrial camera, a security camera, or a web camera that is installed in a fixed position. This allows the imaging means 11 to capture images of the hose 21, the bracket 22, and the clip 23 that connects the hose 21 and the bracket 22, which are provided on the vehicle 2.

[0015] A mobile terminal with a camera, such as a smartphone held by the worker, can be used as the imaging means 11. Alternatively, a wearable camera worn by the worker can be used.

[0016] Alternatively, the imaging means 11 can be a camera held by a robot hand for capturing images. In this case, the robot hand can be controlled in operation by a computer 3 having an identification means 12, an arithmetic means 13, and a determination means 14, or by another computer, and the relative position of the robot hand to the inspection object can be adjusted. Note that the imaging method used for the imaging means 11 is not limited to these, and other methods may also be used.

[0017] The imaging means 11 can capture any location of the vehicle 2. For example, the imaging means 11 can capture images of the inside of the hood from the upper front of the vehicle 2, the inside of the vehicle from the upper rear of the vehicle 2, or from below the vehicle 2. The imaging means 11 can capture at least one of still images and moving images, but the following description will be given assuming that it captures still images.

[0018] The specifying means 12 specifies the positions and sizes of the bracket 22 and clip 23 from the image acquired by the imaging means 11 .

[0019] For example, the identification means 12 can identify the position coordinates of the bracket 22 on the acquired image acquired by the imaging means 11 as (X1, Y1) and the width and height as (x1, y1). In other words, the identification means 12 can identify that the bracket 22 is located within a range of x1 pixels to the right and a range of y1 pixels below the coordinate position (X1, Y1) on the acquired image. Typically, the x1 pixel and y1 pixel are each several tens to several hundreds of pixels.

[0020] Similarly, the identification means 12 can identify the position coordinates of the clip 23 on the image acquired by the imaging means 11 as (X2, Y2) and the horizontal and vertical lengths as (x2, y2). In other words, the identification means 12 can identify that the clip 23 is located in a range of x2 pixels to the right and y2 pixels below the coordinate position (X2, Y2) on the acquired image. Typically, the x2 pixels and y2 pixels are several tens to several hundreds of pixels, respectively.

[0021] The calculation means 13 performs calculations based on the coordinates specified on the image by the specification means 12 so that the determination means 14 can make a determination.

[0022] As an example, the identifying means 12 identifies that the clip 23 is displayed with a height of 60 pixels on the image. Then, the calculating means 13 has size information that the clip 23 is formed with a height of 36 mm in advance, and can calculate that 1 pixel on the image is 0.6 mm. Typically, this size information is the standard value of the size of the clip 23.

[0023] The determining means 14 determines whether the image is good or bad by correlating the number of pixels in the width and height of the object in the image acquired by the identifying means 12 and the number of pixels between the objects.

[0024] As an example, assume that the pixel spacing in the vertical direction between the bottom 22a of the bracket 22 and the clip 23 on the image identified by the identification means 12 is 6 pixels. Here, if it is determined by calculation by the calculation means 13 that 1 pixel is 0.6 mm, then 6 pixels on the image will be 3.6 mm in real space.

[0025] Here, the determining means 14 determines in advance that the gap between the bottom 22a of the bracket 22 and the clip 23 in the height direction is within 2 to 7 mm, and therefore determines that the gap between the bracket 22 and the clip 23 is a non-defective product. As a result, the determining means 14 can determine that the gap specified by the specifying means 12 is 6 pixels on the image, which is equivalent to 3.6 mm in real space, and therefore is a non-defective product.

[0026] Next, the hose 21, bracket 22, and clip 23, which are the objects of inspection, will be described with reference to Figures 2 to 5. Furthermore, an overview of five inspection items performed on these objects of inspection using the inspection device 1 will be described.

[0027] 2 is an example of a view showing, from diagonally above, the external appearance of the inspection object, hose 21, and protrusion 22b of bracket 22 connected and fastened with clip 23. Also, Fig. 3 is an example of a cross-sectional view showing a cross section along the vertical direction of these inspection objects, Fig. 4 is a front view showing the external appearance of these inspection objects from the front, and Fig. 5 is a view showing the open state of claws 23a and 23b, which are both tip ends of clip 23, and is a cross-sectional view showing a horizontal cross section of the location where clip 23 is provided.

[0028] 2 to 4, the hose 21 and the bracket 22 are arranged so that the hose 21 is on the upper side and the bracket 22 is on the lower side. The protruding portions 22b of the hose 21 and the bracket 22 are each cylindrical with their axial direction extending in the vertical direction.

[0029] 3, bracket 22 is provided on top of another component formed with a larger diameter, and protruding portion 22b is cylindrical with its axis in the vertical direction. Meanwhile, the vicinity of the lower portion of hose 21 is hollow cylindrical with its axis in the vertical direction, and cylindrical bracket 22 is inserted into hose 21 at the lower portion of hose 21. In other words, the inner circumferential surface of the lower portion of hose 21 and the outer circumferential surface of protruding portion 22b of bracket 22 abut against each other in an opposing relationship.

[0030] 3, protrusion 22b of bracket 22 will be inserted into hose 21, but if this length is insufficient, i.e., if the insertion is shallow, hose 21 and protrusion 22b of bracket 22 will easily come out. Therefore, the first inspection item is whether or not protrusion 22b of bracket 22 has inserted into hose 21 to a sufficient length. The inspection target location for the first inspection item is indicated as "A" in FIG. 3.

[0031] As shown in FIG. 2, a clip 23 is arranged to be wrapped around the hose 21 in the circumferential direction at a location where the hose 21 and the protruding portion 22b of the bracket 22 are arranged inward and outward.

[0032] That is, clip 23 is formed to be short in the vertical direction and long in the horizontal direction, and is wrapped around hose 21 while tightening it around the outer periphery of hose 21 near the end of hose 21. In this way, clip 23 can press hose 21 inward, and fix hose 21 and protruding portion 22b of bracket 22 together.

[0033] 3, if clip 23 is not positioned appropriately, hose 21 and protrusion 22b of bracket 22 cannot be sufficiently fixed, and hose 21 is likely to come off protrusion 22b of bracket 22. Therefore, the second inspection item is whether or not the distance from the end of hose 21 to the position where clip 23 is positioned is a predetermined distance. The location to be inspected for the second inspection item is indicated as "B" in FIG. 3.

[0034] 2 and 5, clip 23 has claws 23a, 23b at both ends in the extension direction. Clip 23 fastens hose 21 and protruding portion 22b of bracket 22 when claws 23a, 23b mesh with each other at their vicinity and with claws 23a, 23b open within a predetermined range.

[0035] More specifically, if the gap between claws 23a and 23b is less than a predetermined angle, clip 23 will not have enough force to fasten hose 21 to protruding portion 22b of bracket 22, making hose 21 more likely to come off protruding portion 22b of bracket 22. Therefore, the third inspection item is whether the gap between claws 23a and 23b is greater than a predetermined angle, such as 30° or more. The inspection location for the third inspection item is indicated as "C" in FIG. 5.

[0036] On the other hand, if the gap between claw portion 23a and claw portion 23b is too wide, interference with other components may occur, potentially causing damage to those components. Therefore, the fourth inspection item is whether the gap between claw portion 23a and claw portion 23b is equal to or smaller than a predetermined angle, such as 120° or less. The location to be inspected for the fourth inspection item is indicated as "D" in FIG. 5.

[0037] 4, painted marks 21a and 22c for aligning the outer peripheral surface of hose 21 and bottom portion 22a of bracket 22 are provided on the outer peripheral surface of hose 21 and bracket 22. Paint marks 21a and 22c on hose 21 and bracket 22 are provided so that twisting of hose 21 is sufficiently small when they are connected in the correct positions.

[0038] In other words, if the hose 21 and bracket 22 are connected with the paint marks misaligned, the hose 21 will become twisted significantly, which may cause interference with other components and result in damage. Therefore, the fifth inspection item is whether the relative positional deviation between the paint mark 21a on the hose 21 and the paint mark 22c on the bottom 22a of the bracket 22 is within a predetermined range. The location to be inspected for the fifth inspection item is indicated as "E" in Figure 4.

[0039] Here, the paint mark 21a on the hose 21 and the paint mark 22c on the bracket 22 are made substantially on the front side. This front side is the direction in which the claws 23a and 23b are disposed when the clip 23 is wrapped around the hose 21. That is, when the imaging range of the imaging means 11 is set so that the claws 23a and 23b are sufficiently visible, the paint mark 21a on the hose 21 and the paint mark 22c on the bracket 22 are also included in the imaging range at the same time.

[0040] The paint mark 22c on the bottom 22a of the bracket 22 may be placed, for example, near the outer periphery of the bottom 22a, or at another location such as the protrusion 22b, but should be placed in a position that is included in the image captured by the imaging means 11 when the hose 21 and bracket 22 are properly assembled.

[0041] FIG. 6 is a diagram summarizing the first to fifth inspection items, an example of the standards, and an example of a problem that occurs when the hose 21, the bracket 22, and the clip 23 are arranged in a state that does not conform to the standards.

[0042] Next, a detailed example of a method for inspecting each of the first to fifth inspection items using the inspection device 1 will be described.

[0043] When the first to fifth inspection items are performed, the image of the inspection object by the imaging means 11 is taken in a state where the hose 21, bracket 22, and clip 23 are sufficiently within the imaging range. Typically, the imaging means 11 takes an image of the inspection object from the front side and diagonally above. For example, the imaging means 11 can take an image of the inspection object from the front side and diagonally above at an angle of about 30° from the horizontal, but is not limited to this.

[0044] In the following, in order to make the explanation of the test method for each test item easier to understand, the second, fourth, third, first and fifth test items will be explained in that order.

[0045] <Second inspection item> First, we will explain the second inspection item using the inspection device 1. In the second inspection item, we inspect whether the distance from the end of the hose 21 to the position where the clip 23 is arranged is a predetermined distance.

[0046] A common issue when performing multiple of the first to fifth inspection items using the inspection device 1 instead of the human eye is matching the pixels of the image acquired by the imaging means 11 with the length in real space. Here, we will explain the procedure for the inspection method for the second inspection item, as well as how to match the pixels of the acquired image with the length in real space.

[0047] 7 is a flowchart showing the procedure for inspecting the second inspection item using the inspection device 1. As described above, an example of a non-defective product condition in this case can be set as a distance from the end of the hose 21 to the clip 23 being within 2 to 7 mm.

[0048] First, the worker checks the standard size of the object in advance from a drawing or the like, and obtains size information (step S71).

[0049] In a later step, the pixels in the image acquired by the imaging means 11 are converted into lengths in real space, but if there is only one object to be inspected, the accuracy of the conversion between the pixels in the image and the lengths in real space will be low, so the ratio between these is calculated for two objects.

[0050] Here, the first object is the bracket 22, and the second object is the clip 23. Specifically, the following description will be given assuming that information on the vertical lengths of the bracket 22 and the clip 23 in real space is acquired in advance and used.

[0051] The inspection device 1 detects the inspection object to be measured (step S72). Specifically, the imaging means 11 captures an image of the inspection object, and the identification means 12 identifies the size and position of the target area on the acquired image. At this time, the imaging means 11 captures the image while keeping the distance from the imaging means 11 to the inspection objects, hose 21, bracket 22, and clip 23, as close as possible. For example, the image captured by the imaging means 11 should capture a sufficiently long image from the bottom end of bracket 22 to the top end of clip 23.

[0052] The size and position of the target area on the acquired image identified by the identification means 12 here refer to the vertical length and position of bracket 22 on the image, the vertical length and position of clip 23, and the length and position from the end of hose 21 to clip 23. Fig. 8 is a simplified diagram of the acquired image acquired by imaging means 11. As shown in Fig. 8, the identification means 12 identifies the vertical length of bracket 22 on the acquired image as 690 pixels, the vertical length of clip 23 as 70 pixels, and the length from the end of hose 21 to clip 23 as 100 pixels, and the respective positions have been identified.

[0053] At this time, the calculation means 13 can calculate, by identifying the position coordinates of the bracket 22 and clip 23 by the identification means 12, that the point from the end of the hose 21 to the clip 23 ("B" in Figure 4), which is the inspection target point for the second inspection item (inspection content in Figure 6), is located closer to the clip 23 than the bracket 22, and the distance ratio is 1:4.

[0054] 9, the calculation means 13 acquires the vertical center position coordinate (first position coordinate) of the clip 23 identified by the identification means 12, the vertical center position coordinate (second position coordinate) of the bracket 22, and the vertical center position coordinate (third position coordinate) of the distance from the end of the hose 21 to the clip 23. The calculation means 13 then calculates the difference between the vertical distance between the first position coordinate and the third position coordinate and the vertical distance between the second position coordinate and the third position coordinate. As a result, the ratio of the distances is calculated to be 1:4.

[0055] Next, the calculation means 13 uses the information on the position and size of the object to be inspected identified by the identification means 12 in step S72 to calculate the ratio of the pixel for each position in the acquired image to the length in real space (step S73).

[0056] For example, the calculation means 13 can calculate that 1 mm corresponds to 6.9 pixels because the standard vertical length of the bracket 22 in real space, which is known in advance, is 100 mm and its length in the acquired image is 690 pixels. On the other hand, the calculation means 13 can calculate that 1 mm corresponds to 7 pixels because the standard vertical length of the clip 23 in real space, which is known in advance, is 10 mm and its length in the acquired image is 70 pixels.

[0057] Then, since the ratio of the distances calculated in step S72 is 1:4, the calculation means 13 uses this ratio and calculates that 1 mm at the position spaced from the end of the hose 21 to the clip 23 is 6.98 pixels.

[0058] Furthermore, the calculation means 13 can calculate that the distance from the end of the hose 21 identified by the identification means 12 to the clip 23 is 14.32 mm in real space, since it is 100 pixels in the acquired image.

[0059] Finally, the determination means 14 determines whether the distance between the end of the hose 21 and the clip 23 in real space calculated in step S73 meets the condition for a non-defective product (step S74). Here, the condition for a non-defective product is within 2 to 7 mm, and since the distance between the end of the hose 21 and the clip 23 in real space is calculated to be 14.32 mm in step S73, the determination means 14 can determine that the product is not a non-defective product.

[0060] <Fourth inspection item> Next, a fourth inspection item will be described, namely, a method for inspecting whether the gap between claws 23a and 23b of clip 23 is equal to or smaller than a predetermined angle. Fig. 10 is a diagram showing the inspection procedure for the fourth inspection item using inspection device 1.

[0061] 11, the identification means 12 identifies the positions and sizes of the claw portions 23a, 23b and the elliptical portion 21b of the clip 23 (step S101). The identification of each portion by the identification means 12 can utilize AI learning such as deep learning.

[0062] Here, the elliptical portion 21b is a portion of the hose 21 that is approximately circular in cross section when viewed from above and that appears elliptical in the acquired image. The elliptical portion 21b is located above and in the vicinity of the portion of the hose 21 where the clip 23 is wrapped.

[0063] 12, the calculation means 13 calculates the elliptical shape of the elliptical portion 21b (step S102). Specifically, the calculation means 13 calculates the minor axis r x length and major axis r y The degree of inclination of the hose 21 in the diagonal direction is calculated from the length of the hose 21.

[0064] Next, the calculation means 13 assumes that the claws 23a, 23b are located on this ellipse, using the position information of the claws 23a, 23b acquired by the identification means 12. That is, the calculation means 13 sets position coordinates on the ellipse that allow angle calculation of the claws 23a, 23b from the center of the ellipse (step S103).

[0065] Then, as shown in FIG. 13, the calculation means 13 calculates the angles θ1 and θ2 from the center of the ellipse using the position coordinates of the claws 23a and 23b on the ellipse set in step S103 and trigonometric functions (step S104).

[0066] Here, the details of the calculation procedure of angles θ1 and θ2 in steps S103 and S104 will be described. Considering a point P(x, y) on an ellipse as shown in FIG. 14(a),

number

[0067] On the other hand, for example, the coordinates P'(x', y') of the claw portion 23a are calculated by detecting the positions of the claw portions 23a and 23b by the identification means 12. At this time, as shown in FIG. 14(b),

number

[0068] Here, if θ1+θ2 is θ', then

number

[0069] The determining means 14 determines whether or not θ′ calculated in steps S103 and S104 satisfies the conditions for a non-defective product (step S105). As an example, the determining means 14 determines that the product is non-defective if θ′ is within 120°.

[0070] <Third inspection item> Here, the third inspection item, that is, the method of inspecting whether the gap between claw portion 23a and claw portion 23b is equal to or larger than a predetermined angle, can be performed in the same manner as the fourth inspection item.

[0071] In this case, the determination means 14 can make a determination in step S105 shown in FIG. 10 based on whether or not θ′ calculated in steps S103 and S104 is equal to or greater than 30°, which is the non-defective condition.

[0072] <First inspection item> Next, we will explain the first inspection item, i.e., a method for inspecting whether or not the length of protrusion 22b of bracket 22 inserted into hose 21 is sufficient. Fig. 15 is a diagram showing the inspection procedure for the first inspection item using inspection device 1.

[0073] As a preliminary preparation, the inspection device 1 creates correct answer data of the position information of the inspection object, and performs learning using the created correct answer data (step S151).

[0074] Specifically, the inspection device 1 creates a set of multiple correct data, i.e., positional information, for learning by labeling the image acquired in advance by the imaging means 11 and the hose 21 and bracket 22 that appear in the image.

[0075] In this case, when the objects to be labeled are close to each other, the identification means 12 can first perform labeling so that the labeling range is narrower, and then add the narrower labeling range later. By labeling from such a narrow range, the identification means 12 can improve the labeling accuracy. The identification means 12 can include position information and size information of the hose 21 and bracket 22 in the correct answer data created using this labeling.

[0076] The inspection device 1 then uses this correct answer data to learn the positions of the hose 21 and the bracket 22. In the following description, it is assumed that the inspection device 1 has sufficiently learned the position information of the hose 21 and the bracket 22 from a plurality of correct answer data.

[0077] Next, processing is performed using the acquired image showing the hose 21 and bracket 22, which are the actual inspection targets.

[0078] The imaging means 11 acquires an image showing the hose 21 and the bracket 22. Then, the identification means 12 detects the positions of the hose 21 and the bracket 22. Specifically, the identification means 12 identifies the position and type of each object, that is, the hose 21 and the bottom part 22a of the bracket 22 (step S152).

[0079] In particular, the identification means 12 performs object detection to identify the arc shape of the lower end of the hose 21 and the arc shape of the outer periphery of the bottom 22a of the bracket 22 in the acquired image. Fig. 16 shows the two arc shapes identified by the identification means 12 and their positional relationship for determination by the determination means 14.

[0080] Here, the specifying means 12 can specify the positions of the hose 21 and the bracket 22 using the position information of the hose 21 and the bracket 22 learned in step S151.

[0081] As an example, the identification means 12 can perform processing to identify the position of the article, assuming that the positional relationship between the hose 21 and the bracket 22 learned in step S151 is substantially the same as the positional relationship between the hose 21 and the bracket 22 in the image acquired in step S152. That is, the identification means 12 compares the image acquired in step S152 with the content learned using the correct answer data in step S151, and performs processing by estimating the positions of the hose 21 and the bracket 22, thereby being able to identify the positions of the hose 21 and the bracket 22 in the image acquired in S152.

[0082] In addition, in the processing of step S152, the identification means 12 can take the same procedure as in step S151, in that it first identifies the position of the target object within a narrow range and then expands the identified range, but this is not limited to this and the identification procedure can be freely changed.

[0083] Here, the number of pixels in the vertical direction of the arc shape of the front half circumference of the lower end of the hose 21 in the acquired image identified by the identification means 12 is set to α pixels, and the number of pixels in the vertical direction of the arc shape of the front half circumference of the outer periphery of the bottom 22a of the bracket 22 is set to β pixels. This front side is the side closest to the imaging means 11 when imaging is performed by the imaging means 11.

[0084] Furthermore, the difference in vertical position between the coordinates of the upper end of the part identified as the arc shape of the lower end of the hose 21 and the coordinates of the lower end of the part identified as the arc shape of the outer periphery of the bottom 22a of the bracket 22 is defined as γ pixels.

[0085] The calculation means 13 calculates the ratio between the pixel in the image acquired by the imaging means 11 and the length in real space (step S153). This calculation of the ratio can be performed in the same manner as the method shown in steps S71 to S73 of the second inspection item described above, and therefore the explanation will be omitted.

[0086] The calculation means 13 calculates the lengths α'mm, β'mm, and γ'mm in real space for the α pixel, β pixel, and γ pixel on the acquired image calculated in step S152, using the ratios calculated in step S153 (step S154).

[0087] The determining means 14 determines whether or not the result of subtracting α'mm and β'mm from γ'mm calculated in step S153 is within 1 mm, which is the acceptable product condition (step S155).

[0088] <Fifth inspection item> Next, a fifth inspection item, that is, a method for inspecting whether or not the relative positional deviation between the paint mark 21a of the hose 21 and the paint mark 22c provided on the bottom portion 22a of the bracket 22 is within a predetermined range, will be described.

[0089] The identifying means 12 acquires the positions and sizes of the bracket 22 and the clip 23 and the coordinates of the paint mark 21a and the paint mark 22c in the image acquired by the imaging means 11.

[0090] Here, the calculation means 13 calculates the ratio between the pixel in the acquired image acquired by the imaging means 11 and the length in real space. This calculation of the ratio can be performed in the same manner as the method shown in steps S71 to S73 of the second inspection item described above, and therefore detailed explanation will be omitted, but for example, based on the positions and sizes of the bracket 22 and the clip 23, it can be calculated how many millimeters in real space one pixel on the acquired image at the positions of the paint marks 21a and 22c corresponds to.

[0091] 4, the specifying means 12 specifies the horizontal pixel shift between the paint marks 21a and 22c in the acquired image. Then, the calculation means 13 calculates the distance of the real-space shift between the paint marks 21a and 22c from the horizontal pixel shift specified by the specifying means 12.

[0092] The determination means 14 determines whether the deviation distance in real space between the paint marks 21a and 22c calculated by the calculation means 13 is within a predetermined range. As an example, the determination means 14 can determine that the product is non-defective if the deviation distance in real space between the paint marks 21a and 22c is within 3 mm.

[0093] In this way, the inspection device 1 can perform inspections for each of the first inspection item to the fifth inspection item. Note that the inspection device 1 may perform any one of the first inspection item to the fifth inspection item, or may perform a combination of a plurality of the first inspection item to the fifth inspection item.

[0094] <Example of preparation for acquiring images> In the above description, when each of the first to fifth inspection items is performed by the inspection device 1, the bracket 22 is photographed so as to be positioned at the lower center of the image acquired by the imaging means 11, and the hose 21 is photographed so as to be positioned at the upper center of the image, as shown in Fig. 2. Furthermore, when identifying each inspection object by the identification means 12, this is done based on an uninclined rectangle consisting of two horizontal sides and two vertical sides on the acquired image.

[0095] However, as shown in Fig. 17, it is conceivable that the imaging means 11 captures an image of the inspection object so that it is long in the diagonal direction of the acquired image, that is, so that the bracket 22 is positioned in the lower left of the acquired image and the hose is positioned in the upper right of the acquired image. In such a case, if the identification means 12 performs identification processing based on a rectangular shape that is not tilted with respect to the acquired image as shown in Fig. 17, there is a high possibility that the identification will include an extra area in addition to the area that is originally intended to be identified as the inspection object.

[0096] Therefore, the inspection device 1 performs image processing on the acquired image captured by the imaging means 11, and can create a processed image in which the bracket 22 is positioned at the bottom center of the acquired image and the hose 21 is positioned at the top center of the acquired image. An example of the procedure for creating this processed image is shown below.

[0097] First, when the inspection object in the image acquired by the imaging means 11 is tilted as shown in Fig. 17, the identification means 12 acquires the positions and sizes of the two inspection objects. Here, the identification means 12 identifies the positions and sizes of the arc-shaped region at the lower end of the bracket 22 and the arc-shaped region at the lower end of the hose 21.

[0098] At this time, the specifying means 12 specifies the position and size of these areas based on an uninclined rectangle consisting of two horizontal sides and two vertical sides on the acquired image. Therefore, when the specifying means 12 specifies the arc-shaped area at the bottom end of the bracket 22, it includes the area surrounding this area, and similarly, when the specifying means 12 specifies the arc-shaped area at the bottom end of the hose 21, it includes the area surrounding this area.

[0099] Next, the calculation means 13 calculates the center coordinates (first center coordinates) of the arc-shaped area at the lower end of the bracket 22 identified by the identification means 12. Similarly, the calculation means 13 calculates the center coordinates (second center coordinates) of the arc-shaped area at the lower end of the hose 21 identified by the identification means 12.

[0100] Next, as shown in FIG. 18, the calculation means 13 connects the first center coordinate and the second center coordinate with a straight line, and can calculate the tilt angle of the inspection object in the acquired image from the angle of this line.

[0101] Therefore, the calculation means 13 performs projective transformation on the acquired image based on the calculated tilt angle, and can create a processed image in which the bracket 22 is positioned at the center of the bottom and the hose 21 is positioned at the center of the top.

[0102] This allows the position and angle of the object to be inspected in the image captured by the imaging means 11 to be converted so that the processing of the first to fifth inspection methods can be easily performed on the image.

[0103] From the above, the inspection device 1 can automatically judge whether the first to fifth inspection items are good or bad by associating the pixels in the image acquired by the imaging means 11 with the length of the object to be inspected in real space.

[0104] Specifically, in the inspection device 1, the imaging means 11 captures an image of the assembled state, and the identification means 12 can identify the respective positions and sizes of the clip 23 and the bracket 22 from the acquired image captured by the imaging means 11. The calculation means 13 can associate pixels in the acquired image with lengths in real space using the respective positions of the clip 23 and the bracket 22 identified by the identification means 12 and their sizes in the acquired image, and the standard sizes in real space of the clip 23 and the bracket 22 acquired in advance. Furthermore, the determination means 14 can use this association to determine the pass / fail of the assembled state for each inspection item, using the length in real space of the inspection target portion calculated from the size in the acquired image.

[0105] In this way, the inspection device 1 can automatically judge whether an object is good or bad, saving the time and effort of an inspector having to perform a visual inspection. Also, since there is no need to deploy an inspector, the length of the production line can be shortened and the occurrence of human error can be reduced.

[0106] Furthermore, in the inspection device 1, the pass / fail judgment is performed after the correspondence between the pixel size in the acquired image and the length in real space is known, thereby improving the judgment accuracy.

[0107] Furthermore, as shown in the third and fourth inspection items, even in a situation where the claw portions 23a, 23b of the clip 23 must be photographed from an oblique direction using the imaging means 11, the degree of opening of the claw portions 23a, 23b can be determined.

[0108] The present invention is not limited to the above-described embodiment, and can be appropriately modified without departing from the spirit of the present invention. In other words, the above description has been omitted or simplified as appropriate for the sake of clarity, and a person skilled in the art can easily modify, add, or convert each element of the embodiment within the scope of the present invention.

[0109] For example, although the above description has been given assuming that the correspondence between pixels in the acquired image and lengths in real space is based particularly on the positions and sizes of bracket 22 and clip 23, it is also possible to correspond pixels in the acquired image and lengths in real space of hose 21 or other inspection objects not listed above. Furthermore, it is also possible to use three or more of these components to correspond pixels in the acquired image and lengths in real space. [Explanation of symbols]

[0110] 1. Inspection equipment 2 vehicles 3. Computer 11 Imaging means 12 Specific means 13 Calculation means 14 Judgment means 21 Hose 22 Bracket 23 clips

Claims

[Claim 1] An inspection method for inspecting an assembly state of a hose, a bracket, and a clip that joins the hose and the bracket, comprising: The imaging means images the assembled state, The identifying means identifies the respective positions and sizes of the clip and the bracket from the captured image acquired by the imaging means, a calculation means for associating pixels in the acquired image with lengths in real space by using the positions and sizes in the acquired image of the clip and the bracket identified by the identification means and the sizes in real space of the clip and the bracket that have been acquired in advance; The determination means is When determining whether the assembly state is good or bad using the length in real space of the inspection target portion calculated from the size in the acquired image by the association, Assuming that the cross section of the hose is circular, and assuming that the hose in the acquired image has a shape that combines a part of an ellipse arc and a straight line, the inclination of the hose is calculated, and the calculated inclination of the hose is used to calculate the angle between the two claws provided on the clip, and the quality of the claws is determined, a determination of the length of the protrusion provided on the bracket that has penetrated into the hose is made based on the arc shape of the front half of the circumference of the lower end of the hose, which is elliptical in the acquired image, and the arc shape of the front half of the circumference of the bottom of the bracket; Testing method.

Images