Needle inspection device

Abstract

Technical problem: Checking sewing needles with high precision. Solution: A sewing needle inspection device includes: a first camera device that photographs a sewing needle held on a needle bar of a sewing machine; a second camera device that photographs the sewing needle; and a processing device that outputs inspection data of the sewing needle based on a first image obtained by the first camera device and a second image obtained by the second camera device. The first camera device and the second camera device are configured so that a first optical axis representing an optical axis of the first camera device and a second optical axis representing an optical axis of the second camera device are orthogonal to the sewing needle.

Description

Technical Field

[0001] The present disclosure relates to a suture needle inspection device. Background Art

[0002] In the technical field of sewing machines, a sewing machine including an imaging unit as disclosed in Patent Document 1 is known.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2009-189551 Summary of the invention

[0006] 1. Technical issues to be resolved

[0007] There is a situation where images of the suture needle are obtained by a plurality of imaging devices respectively and the suture needle is inspected based on the plurality of images. It is possible that it is difficult to inspect the suture needle with high accuracy due to the relative positions of the plurality of imaging devices.

[0008] The purpose of the present disclosure is to inspect suture needles with high accuracy.

[0009] (II) Technical solution

[0010] According to the present disclosure, a sewing needle inspection device is provided, which comprises: a first camera device, which photographs a sewing needle held on a needle bar of a sewing machine; a second camera device, which photographs the sewing needle; and a processing device, which outputs inspection data of the sewing needle based on a first image obtained by the first camera device and a second image obtained by the second camera device, the first camera device and the second camera device being configured so that a first optical axis representing an optical axis of the first camera device and a second optical axis representing an optical axis of the second camera device are orthogonal on the sewing needle.

[0011] (III) Beneficial effects

[0012] According to the present disclosure, it is possible to inspect a suture needle with high accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a perspective view schematically showing a sewing machine according to the embodiment.

[0014] Figure 2 It is a top view schematically showing a sewing needle inspection device according to an embodiment.

[0015] Figure 3 It is a diagram for explaining a camera coordinate system according to the embodiment.

[0016] Figure 4 2 is a block diagram showing a sewing needle inspection device according to an embodiment.

[0017] Figure 5 is a flow chart showing a method for inspecting a sewing needle according to an embodiment.

[0018] Figure 6 is a diagram showing a calibration tool according to an embodiment.

[0019] Figure 7 It is a diagram showing the usage state of the calibration tool according to the embodiment.

[0020] Figure 8 This is a diagram showing an example of a first image of a calibration tool obtained by a first imaging device according to an embodiment.

[0021] Fig. 9 This is a diagram showing an example of a second image of a calibration tool obtained by a second imaging device according to an embodiment.

[0022] Fig.10 It is a diagram for explaining the reference axis measuring tool and the calculation method of the needle reference axis according to the embodiment.

[0023] Fig.11 is a flowchart showing a calibration process according to an embodiment.

[0024] Fig.12 : is a flowchart showing the focus adjustment process according to the embodiment.

[0025] Fig.13 This is a diagram for explaining a method for calculating edge sharpness of a grid according to an embodiment.

[0026] Fig.14 Detailed Description of the Invention It is a flowchart showing the pixel ratio calculation process according to the embodiment.

[0027] Fig.15 It is a diagram for explaining the pixel ratio calculation processing of the embodiment.

[0028] Fig.16 It is a diagram for explaining the relative camera angle calculation process according to the embodiment.

[0029] Fig.17 This is a diagram showing an example of first image data of a calibration tool obtained by a first imaging device in the relative camera angle calculation process of the embodiment.

[0030] Fig.18 It is a diagram for explaining the distance Vsz and the distance Ksz according to the embodiment.

[0031] Fig.19 is a flowchart showing a needle inspection process according to an embodiment.

[0032] Fig. 20 : is a flowchart showing the needle registration process according to the embodiment.

[0033] Fig.21 It is a diagram for explaining reference feature quantities of a sewing needle according to an embodiment.

[0034] Fig. 22 : is a flowchart showing the needle inspection process according to the embodiment.

[0035] Fig.23 It is a diagram for explaining the detection feature quantity of the sewing needle according to the embodiment.

[0036] Fig.24 It is a diagram showing an example of a first image of a sewing needle according to an embodiment.

[0037] Fig.25 This is a diagram showing an example of an image processing method for a first image according to an embodiment.

[0038] Fig.26 This is a diagram showing an example of an image processing method for a first image according to an embodiment.

[0039] Fig. 27 It is a diagram showing an example of a method for calculating the deformation amount of a bent and deformed suture needle according to an embodiment.

[0040] Description of Reference Numerals

[0041] 1-sewing machine; 2-sewing machine head; 3-needle; 3R-reference needle; 3S-detection needle; 4-needle bar; 5-needle plate; 6-presser foot component; 7-needle hole; 10-needle inspection device; 11-first camera device; 12-second camera device; 13-processing device; 13A-image acquisition unit; 13B-calibration unit; 13C-calibration storage unit; 13D-reference feature quantity calculation unit; 13E-reference feature quantity storage unit; 13F-detection feature quantity calculation unit; 13G-inspection unit; 14-output device; 20-calibration tool; 21-plate; 22-grid; 22A-uppermost grid line; 22B-lowermost grid line; 23-judgment range; 24-simulation grid line; 3 0-reference axis measurement tool; AX1-first optical axis; AX2-second optical axis; AR-minimum width; AS-minimum width; BR-maximum width; BS-maximum width; CR-needle tip angle; CS-needle tip angle; DS-deformation; EA-discontinuous edge interval; FA-field of view; ID1-first image; ID2-second image; Ksz-distance; LR-length; LS-length; Lv-imaginary vertical field of view; NP-needle position; NX-needle reference axis; NXo-center; P1-intersection; P2-intersection; Pl-point; Pr-point; PS-sewing position; Rv-imaginary vertical field of view; S-sewing object; SE-stitch; Vsz-distance; θ-angle. DETAILED DESCRIPTION

[0042] The following describes the embodiments of the present disclosure with reference to the accompanying drawings, but the present disclosure is not limited thereto. The structural elements of the embodiments described below can be combined as appropriate. In addition, there is also a case where some structural elements are not used.

[0043] In the embodiment, the positional relationship of each part is described based on the sewing machine coordinate system defined in the sewing machine 1. The sewing machine coordinate system is defined by a three-dimensional orthogonal coordinate system. The sewing machine coordinate system is defined by an Xm axis, a Ym axis, and a Zm axis. The Xm axis is defined in a defined plane. The Ym axis is defined to be orthogonal to the Xm axis in the defined plane. The Zm axis is defined to be orthogonal to the defined plane. In the embodiment, it is assumed that the defined plane is parallel to the horizontal plane, and the direction parallel to the Zm axis is the up and down direction. In addition, in the embodiment, the defined plane is appropriately referred to as the XmYm plane.

[0044] [Sewing machine]

[0045] Figure 1 1 is a perspective view schematically showing a sewing machine 1 according to an embodiment. Figure 1 As shown, the sewing machine 1 comprises: a sewing machine head 2, a needle bar 4 that holds the sewing needle 3 and reciprocates along the Z-axis direction, a needle plate 5 that supports the sewing object S, a presser foot component 6 that presses the sewing object S, and a needle inspection device 10 that inspects the sewing needle 3.

[0046] The sewing machine head 2 supports the needle bar 4 in a manner that allows reciprocating movement in the Zm-axis direction. The needle bar 4 is disposed above the needle plate 5 and can face the surface of the sewing object S. The needle bar 4 holds the upper end of the sewing needle 3 in a manner that the sewing needle 3 extends in the Zm-axis direction. The upper thread is hung on the sewing needle 3.

[0047] The needle plate 5 supports the back side of the sewing object S. The upper surface of the needle plate 5 is parallel to the XmYm plane. The needle plate 5 supports the sewing object S from below. The needle plate 5 has a needle hole 7 through which the sewing needle 3 can pass. A kettle (not shown) is arranged below the needle plate 5. The kettle holds the bobbin housed in the bobbin box. The bobbin is wound with the lower thread. The kettle rotates synchronously with the reciprocating movement of the needle bar 4. The lower thread is supplied from the kettle.

[0048] The presser foot member 6 presses the sewing object S from above. The presser foot member 6 is supported by the sewing machine head 2. The presser foot member 6 is arranged above the needle plate 5 and contacts the surface of the sewing object S. The presser foot member 6 holds the sewing object S between the needle plate 5 and the presser foot member 6.

[0049] When the needle bar 4 descends, the sewing needle 3 held by the needle bar 4 penetrates the sewing object S and passes through the needle hole 7 provided in the needle plate 5. When the sewing needle 3 passes through the needle hole 7 of the needle plate 5, the lower thread supplied from the kettle is hung on the upper thread hung on the sewing needle 3. In a state where the lower thread is hung on the upper thread, the sewing needle 3 rises and withdraws from the sewing object S. When the sewing needle 3 penetrates the sewing object S, the sewing object S stops. When the sewing needle 3 withdraws from the sewing object S, the sewing object S is moved in the +Ym direction by the feed mechanism of the sewing machine 1. The sewing machine 1 forms a stitch SE on the sewing object S by reciprocating the sewing needle 3 while repeating the movement and stop of the sewing object S in the +Ym direction. The stitch SE formed on the sewing object S extends along the Ym-axis direction.

[0050] In the following description, the position directly below the sewing needle 3 is appropriately referred to as a sewing position PS. In the XmYm plane, the sewing position PS coincides with the position of the sewing needle 3. The sewing needle 3 penetrates the sewing object S at the sewing position PS.

[0051] [Needle inspection device]

[0052] Figure 2 FIG. 2 is a top view schematically showing a needle inspection device 10 according to an embodiment. Figure 1 and Figure 2 As shown, the sewing needle inspection device 10 includes: a first imaging device 11, a second imaging device 12, a processing device 13, and an output device 14.

[0053] The sewing needle 3 is held on the needle bar 4 so as to extend in the Zm axis direction. The first camera 11 and the second camera 12 respectively photograph the sewing needle 3 held on the needle bar 4. The first camera 11 and the second camera 12 respectively photograph the sewing needle 3 when the needle bar 4 and the sewing needle 3 are stationary.

[0054] The first camera 11 and the second camera 12 can simultaneously photograph the sewing needle 3. The first camera 11 can also photograph the sewing needle 3 before the second camera 12 photographs the sewing needle 3. The first camera 11 can also photograph the sewing needle 3 after the second camera 12 photographs the sewing needle 3.

[0055] The first camera device 11 photographs the sewing needle 3 and obtains a first image ID1 of the sewing needle 3. The first camera device 11 outputs the first image ID1 of the sewing needle 3 to the processing device 13.

[0056] The second camera device 12 photographs the sewing needle 3 and obtains a second image ID2 of the sewing needle 3. The second camera device 12 outputs the second image ID2 of the sewing needle 3 to the processing device 13.

[0057] The first imaging device 11 includes an optical system and an image sensor that receives light through the optical system. Examples of the image sensor include a CCD (Couple Charged Device) image sensor and a CMOS (Complementary Metal Oxide Semiconductor) image sensor.

[0058] The second imaging device 12 includes an optical system and an image sensor that receives light via the optical system. Examples of the image sensor include a CCD (Couple Charged Device) image sensor and a CMOS (Complementary Metal Oxide Semiconductor) image sensor.

[0059] In the following description, the optical axis of the optical system of the first imaging device 11 is referred to as the first optical axis AX1, and the optical axis of the optical system of the second imaging device 12 is referred to as the second optical axis AX2.

[0060] The first camera 11 and the second camera 12 are arranged at different positions on the XmYm plane. The first camera 11 and the second camera 12 are arranged so that the first optical axis AX1 and the second optical axis AX2 are orthogonal to the sewing needle 3. The first optical axis AX1 intersects at least a portion of the sewing needle 3. The second optical axis AX2 intersects at least a portion of the sewing needle 3.

[0061] The first camera device 11 is arranged such that the first optical axis AX1 is parallel to the XmYm plane. The second camera device 12 is arranged such that the second optical axis AX2 is parallel to the XmYm plane. The first optical axis AX1 and the second optical axis AX2 are parallel to the XmYm plane respectively.

[0062] In the Zm axis direction, the first optical axis AX1 and the second optical axis AX2 substantially coincide with each other. In addition, in the Zm axis direction, the first optical axis AX1, the second optical axis AX2, and at least a portion of the sewing needle 3 held by the needle bar 4 coincide with each other.

[0063] That is, the first camera 11 and the second camera 12 each photograph the sewing needle 3 from the side while being arranged at substantially the same height as the sewing needle 3. The first camera 11 and the second camera 12 photograph the sewing needle 3 from different directions in the XmYm plane.

[0064] The processing device 13 includes a computer system and outputs inspection data of the sewing needle 3 to the output device 14 based on the first image ID1 of the sewing needle 3 obtained by the first imaging device 11 and the second image ID2 of the sewing needle 3 obtained by the second imaging device 12 .

[0065] The output device 14 outputs the inspection data of the sewing needle 3 supplied from the processing device 13. A display device such as a flat panel display and a printing device such as an inkjet printer are exemplified as the output device 14. In the embodiment, it is assumed that the output device 14 is a display device.

[0066] [Camera coordinate system]

[0067] Figure 3 This is a diagram for explaining the camera coordinate system of the embodiment. The structure and optical characteristics of the first camera device 11 are the same as the structure and optical characteristics of the second camera device 12. A camera coordinate system is defined in each of the first camera device 11 and the second camera device 12. The camera coordinate system is defined by a three-dimensional orthogonal coordinate system. The camera coordinate system is defined by an Xc axis, a Yc axis, and a Zc axis. The Xc axis is defined in a specified plane parallel to the camera surface (incident surface) of the image sensor. The Yc axis is defined to be orthogonal to the Xc axis in the specified plane. The Zc axis is defined to be orthogonal to the specified plane.

[0068] In the embodiment, the Xc axis is parallel to the Zm axis. The Yc axis is parallel to the XmYm plane. The field of view FA of each optical system of the first camera 11 and the second camera 12 is a rectangular shape. The field of view of each optical system of the first camera 11 and the second camera 12 is 10.0 [mm] in the Xc axis direction and 7.5 [mm] in the Yc axis direction. In addition, each image sensor of the first camera 11 and the second camera 12 has 640 pixels.

[0069] [Processing device]

[0070] Figure 4 is a block diagram showing a needle inspection device 10 according to an embodiment. Figure 4 As shown, the sewing needle inspection device 10 includes: a first imaging device 11, a second imaging device 12, a processing device 13, and an output device 14.

[0071] The processing device 13 processes the first image ID1 of the sewing needle 3 obtained by the first imaging device 11 and the second image ID2 of the sewing needle 3 obtained by the second imaging device 12, and outputs inspection data indicating the inspection result of the sewing needle 3. The inspection data contains no abnormality of the sewing needle 3.

[0072] The abnormality of the sewing needle 3 includes bending deformation of the sewing needle 3. In the embodiment, the processing device 13 performs image processing on the first image ID1 and the second image ID2, and determines that there is bending deformation of the sewing needle 3. The processing device 13 performs image processing on the first image ID1 and the second image ID2, and calculates the deformation amount DS of the bent and deformed sewing needle 3. The inspection data includes the deformation amount DS of the bent and deformed sewing needle 3.

[0073] like Figure 4 As shown, the processing device 13 includes an image acquisition unit 13A, a calibration unit 13B, a calibration storage unit 13C, a reference feature quantity calculation unit 13D, a reference feature quantity storage unit 13E, a detection feature quantity calculation unit 13F, and an inspection unit 13G.

[0074] The image acquisition unit 13A acquires the first image ID1 of the sewing needle 3 from the first imaging device 11. The image acquisition unit 13A acquires the second image ID2 of the sewing needle 3 from the second imaging device 12.

[0075] The calibration unit 13B performs arithmetic processing for calibrating the first imaging device 11 and the second imaging device 12 in the calibration process SA of the first imaging device 11 and the second imaging device 12 .

[0076] The calibration storage unit 13C stores data related to calibration obtained in the calibration process SA.

[0077] The reference feature amount calculation unit 13D calculates the first reference feature amount based on the first image ID1 of the sewing needle 3 held by the needle bar 4. The reference feature amount calculation unit 13D calculates the second reference feature amount based on the second image ID2 of the sewing needle 3 held by the needle bar 4.

[0078] The reference feature amount storage unit 13E stores the first reference feature amount and the second reference feature amount of the sewing needle 3. In the embodiment, the reference feature amount storage unit 13E stores the first reference feature amount and the second reference feature amount calculated by the reference feature amount calculation unit 13D.

[0079] The detection feature quantity calculation unit 13F performs image processing on the first image ID1 of the sewing needle 3 obtained by the image acquisition unit 13A to calculate the first detection feature quantity of the sewing needle 3. The detection feature quantity calculation unit 13F performs image processing on the second image ID2 of the sewing needle 3 obtained by the image acquisition unit 13A to calculate the second detection feature quantity of the sewing needle 3.

[0080] In the embodiment, the suture needle 3 includes a reference suture needle 3R and a detection suture needle 3S of the inspection object.

[0081] The reference sewing needle 3R is a normal sewing needle 3. That is, the reference sewing needle 3R is a sewing needle 3 without abnormality. A new sewing needle 3 is exemplified as the reference sewing needle 3R.

[0082] The detection sewing needle 3S is a sewing needle 3 that has been used for sewing. The detection sewing needle 3S is a sewing needle 3 that may have an abnormality. As the detection sewing needle 3S, a reference sewing needle 3R that has been used is exemplified.

[0083] In the embodiment, the reference feature quantity calculation unit 13D calculates the first reference feature quantity of the reference needle 3R based on the first image ID1 of the reference needle 3R held on the needle bar 4. The reference feature quantity calculation unit 13D calculates the second reference feature quantity of the reference needle 3R based on the second image ID2 of the reference needle 3R.

[0084] The detection feature quantity calculation unit 13F performs image processing on the first image ID1 of the detection needle 3S held on the needle bar 4 to calculate the first detection feature quantity of the detection needle 3S. The detection feature quantity calculation unit 13F performs image processing on the second image ID2 of the detection needle 3S held on the needle bar 4 to calculate the second detection feature quantity of the detection needle 3S.

[0085] The inspection unit 13G compares the first detection feature quantity with the first reference feature quantity and compares the second detection feature quantity with the second reference feature quantity to output inspection data representing the inspection result of the sewing needle 3 (detected sewing needle 3S).

[0086] [Needle inspection method]

[0087] Figure 5 is a flow chart showing a method for inspecting a sewing needle according to an embodiment. Figure 5 As shown, the suture needle inspection method includes a calibration process SA and a suture needle inspection process SB.

[0088] <Calibration Processing>

[0089] The calibration process SA is described below. The calibration process SA is a process of calibrating the first imaging device 11 and the second imaging device 12 respectively.

[0090] In the calibration process, the calibration tool 20 and the reference axis measurement tool 30 are used.

[0091] (Calibration fixture)

[0092] Figure 6 2 is a diagram showing an example of a calibration tool 20 according to an embodiment. Figure 6As shown, the calibration tool 20 includes a plate 21 and a pattern of a grid 22 formed on the plate 21. The plate 21 is made of glass. The plate 21 is a parallel plate. That is, the surface and the back of the plate 21 are respectively flat, and the surface and the back of the plate 21 are parallel. The outer shape of the plate 21 is square. The length of one side of the plate 21 is 30 [mm]. The thickness of the plate 21 is 3 [mm]. The surface of the plate 21 is white. The grid 22 is black. A black grid 22 is provided on the surface of the white plate 21. The interval between the grids 22 is 1 [mm], and the line width of the grid 22 is 100 [μm].

[0093] Figure 7 1 is a diagram showing the use state of the calibration tool 20 of the embodiment. The needle position NP is specified in the sewing machine 1. The needle position NP is the position where the sewing needle 3 is set in the XmYm plane. The needle position NP indicates the target position of the sewing needle 3. The needle position NP is the center of the needle bar 4 in the XmYm plane. The needle position NP can be specified in the sewing machine coordinate system based on, for example, the design data of the sewing machine 1.

[0094] In the calibration process SA, the calibration tool 20 is set on the sewing machine 1 in such a way that the surface of the calibration tool 20 is orthogonal to the XmYm plane. The calibration tool 20 is set on the sewing machine 1 in such a way that the surface of the calibration tool 20 is consistent with the needle position NP. The first camera device 11 is configured so that the first optical axis AX1 intersects the surface of the calibration tool 20 at an angle of 45[°]. The second camera device 12 is configured so that the second optical axis AX2 intersects the surface of the calibration tool 20 at an angle of 45[°]. The first camera device 11 and the second camera device 12 are configured so that the first optical axis AX1 intersects the second optical axis AX2 at an angle of 90[°]. The first camera device 11 and the second camera device 12 respectively photograph the calibration tool 20.

[0095] Figure 8 1 is a diagram showing an example of the first image ID1 of the calibration tool 20 obtained by the first imaging device 11 according to the embodiment. Fig. 9 1 is a diagram showing an example of the second image ID2 of the calibration tool 20 obtained by the second imaging device 12 according to the embodiment.

[0096] (Reference axis measurement fixture)

[0097] Fig.10 1 is a diagram for explaining the reference axis measuring tool 30 and the calculation method of the needle reference axis NX according to the embodiment. Fig.10 As shown, the reference axis measurement tool 30 is held by the needle bar 4. The reference axis measurement tool 30 is, for example, a straight metal bar. The first imaging device 11 and the second imaging device 12 each capture an image of the reference axis measurement tool 30 held by the needle bar 4.

[0098] The image acquisition unit 13A acquires the first image ID1 of the reference axis measurement tool 30 acquired by the first imaging device 11 and the second image ID2 of the reference axis measurement tool 30 acquired by the second imaging device 12. The calibrating unit 13B calculates the needle reference axis NX based on the first image ID1 of the reference axis measurement tool 30 and the second image ID2 of the reference axis measurement tool 30.

[0099] The needle reference axis NX is an axis connecting the center of the needle bar 4 and the center of the needle hole 7. By obtaining the first image ID1 and the second image ID2 of the reference axis measurement tool 30, the needle reference axis NX in the first image ID1 and the needle reference axis NX in the second image ID2 are calculated.

[0100] The position of the needle reference axis NX in the first image ID1 and the position of the needle reference axis NX in the second image ID2 are respectively stored in the calibration storage unit 13C. The position of the needle reference axis NX in the first image ID1 and the position of the needle reference axis NX in the second image ID2 are respectively the positions of the needle reference axis NX in the camera coordinate system.

[0101] In addition, Fig.10 An example in which a first image ID1 of the reference axis measurement tool 30 obtained by the first imaging device 11 and a second image ID2 of the reference axis measurement tool 30 obtained by the second imaging device 12 are simultaneously described.

[0102] Fig.11 is a flow chart showing the calibration process SA of an embodiment. Fig.11 As shown, the calibration process SA includes a focus adjustment process SA1, a pixel ratio calculation process SA2, and a relative camera angle calculation process SA3.

[0103] (Focus adjustment)

[0104] The focus adjustment process SA1 of each of the first imaging device 11 and the second imaging device 12 is performed. Figure 7 As described, in the focus adjustment process SA1 , the calibration jig 20 is set on the sewing machine 1 .

[0105] Fig.12 1 is a flowchart showing the focus adjustment process SA1 according to the embodiment. The focus adjustment process SA1 of the first imaging device 11 will be described below.

[0106] When performing focus adjustment of the first imaging device 11 , the calibration unit 13B sets the focus of the optical system of the first imaging device 11 (step SA11 ).

[0107] After setting the focus, the calibration unit 13B uses the first imaging device 11 to capture an image of the calibration tool 20 (step SA12 ).

[0108] The first image ID1 of the calibration tool 20 is obtained by the image obtaining unit 13A. After obtaining the first image ID1 of the calibration tool 20, the calibration unit 13B calculates the sharpness of the edge of the grid 22 in the first image ID1 (step SA13).

[0109] Fig.13 2 is a diagram for explaining a method for calculating the sharpness of the edge of the grid 22 according to the embodiment. Fig.13 As shown, the calibration unit 13B sets a part of the first image ID1 as the determination range 23. The calibration unit 13B calculates the sharpness of the edge of the grid 22 in the determination range 23. The calibration unit 13B calculates the sharpness based on, for example, the sum of squares of density differences between adjacent pixels.

[0110] The sharpness calculated in step SA13 is output to the calibration storage unit 13C. The calibration storage unit 13C compares the input sharpness with the already stored sharpness, and the higher sharpness is stored in the calibration storage unit 13C (step SA14).

[0111] The processing from step SA11 to step SA14 is repeated. If the maximum resolution in the calibration storage unit 13C is not updated a predetermined number of times even if the focus is changed, the processing is terminated.

[0112] The focus adjustment process SA1 of the second imaging device 12 is the same as the focus adjustment process SA1 of the first imaging device 11. The description of the focus adjustment process SA1 of the second imaging device 12 is omitted.

[0113] (Pixel rate calculation)

[0114] After the focus adjustment process SA1 is completed, the pixel ratio calculation process SA2 of each of the first imaging device 11 and the second imaging device 12 is performed. Fig.14 2 is a flowchart showing the pixel ratio calculation process SA2 according to the embodiment. The pixel ratio calculation process SA2 of the first imaging device 11 will be described below.

[0115] When calculating the pixel rate of the first camera device 11, as shown in FIG. Fig.10 As described above, the calibration unit 13B calculates the needle reference axis NX (step SA21 ).

[0116] Next, the calibration unit 13B calculates the pseudo grid lines 24 passing through the center of the needle reference axis NX (step SA22 ).

[0117] Fig.15 1 is a diagram for explaining the pixel ratio calculation process SA2 according to the embodiment. Fig.15As shown, the calibration unit 13B calculates the pseudo grid lines 24 passing through the center NXo of the needle reference axis NX in the first image ID1. The pseudo grid lines 24 are lines passing through the center NXo and parallel to the Xc axis.

[0118] Next, the calibration unit 13B calculates the intersection point P1 of the simulated grid line 24 and the uppermost grid line 22A which is arranged at the most +Xc side (+Zm side) in the first image ID1 and is substantially parallel to the XmYm plane. In addition, the calibration unit 13B calculates the intersection point P2 of the simulated grid line 24 and the lowermost grid line 22B which is arranged at the most -Xc side (-Zm side) in the first image ID1 and is substantially parallel to the XmYm plane (step SA23).

[0119] Next, the calibration unit 13B calculates the pixel ratio based on the pixel distance between the intersection point P1 and the intersection point P2 and the actual distance between the intersection point P1 and the intersection point P2 (step SA24 ).

[0120] The pixel ratio calculation process SA2 of the second camera 12 is the same as the pixel ratio calculation process SA2 of the first camera 11. The description of the pixel ratio calculation process SA2 of the second camera 12 is omitted.

[0121] (Computed relative to camera angle)

[0122] After the pixel ratio calculation process SA2 is completed, a relative camera angle calculation process SA3 is performed to indicate the relative angle between the first camera 11 and the second camera 12. Figure 7 A calibration tool 20 is described.

[0123] Fig.16 It is a diagram for explaining the relative camera angle calculation process SA3 according to the embodiment. Fig.17 This is a diagram showing an example of first image data of the calibration tool 20 obtained by the first imaging device 11 in the relative camera angle calculation process SA3 according to the embodiment. Fig.17 Indicated in Fig.16 In the state shown, the first image ID1 of the calibration tool 20 is obtained by the first camera 11 . Fig.18 It is a diagram for explaining the distance Vsz and the distance Ksz according to the embodiment.

[0124] The imaging surface of the image sensor of the first imaging device 11 is parallel to the Xc axis and the Yc axis. Fig.16 As shown in FIG. 1 , the angle θ formed between the Xc axis parallel to the imaging plane and the first optical axis AX1 can be calculated based on the distance Ksz and the distance Vsz.

[0125] like Fig.16 and Fig.18As shown in FIG. 1 , the distance Ksz is the Yc-axis dimension of the field of view of the first camera 11 in the camera coordinate system. The distance Ksz is the distance between the point Pr at the end of the +Yc side of the field of view and the point P1 at the end of the -Yc side of the field of view. The distance Vsz is the distance between the point Pr and the point P1.

[0126] like Fig.18 As shown, the virtual vertical field of view Rv of the predetermined point Pr. The virtual vertical field of view Lv of the predetermined point P1. The virtual vertical field of view refers to the field of view in the vertical direction (Yc direction) of the image when the calibration tool 20 is assumed to be parallel to the imaging surface.

[0127] <Needle Inspection and Processing>

[0128] Next, the sewing needle inspection process SB will be described. The sewing needle inspection process SB is a process for inspecting the sewing needle 3 based on the first image ID1 of the sewing needle 3 obtained by the first imaging device 11 and the second image ID2 of the sewing needle 3 obtained by the second imaging device 12 .

[0129] Fig.19 4 is a flowchart showing a sewing needle inspection process SB according to an embodiment. Fig.19 As shown, the sewing needle inspection process SB includes a needle registration process SB1 and a needle inspection process SB2.

[0130] Fig. 20 1 is a flowchart showing the needle registration process SB1 of the embodiment. The needle registration process SB1 includes a process of photographing a normal reference needle 3R. In the embodiment, the reference needle 3R is a new needle 3. The reference needle 3R is held on the needle bar 4. The first camera 11 and the second camera 12 each photograph the reference needle 3R held on the needle bar 4.

[0131] The first image ID1 of the reference needle 3R obtained by the first imaging device 11 and the second image ID2 of the reference needle 3R obtained by the second imaging device 12 are obtained by the image obtaining unit 13A (step SB11 ).

[0132] The reference feature quantity calculation unit 13D calculates the first reference feature quantity based on the first image ID1 of the reference needle 3R held on the needle bar 4, and calculates the second reference feature quantity based on the second image ID2 of the reference needle 3R held on the needle bar 4 (step SB12).

[0133] Fig.21 3 is a diagram for explaining the reference feature quantity of the sewing needle 3 according to the embodiment. The reference feature quantity includes at least one of the first reference feature quantity and the second reference feature quantity. Fig.21As shown, the reference characteristic quantities of the sewing needle 3 include: the length LR of the reference sewing needle 3R, the minimum width AR representing the minimum value of the width of the reference sewing needle 3R, the maximum width BR representing the maximum value of the width of the reference sewing needle 3R, and the needle tip angle CR representing the angle of the front end portion of the reference sewing needle 3R.

[0134] The reference feature amount storage unit 13E stores the first reference feature amount and the second reference feature amount calculated by the reference feature amount calculation unit 13D in step SB12 (step SB13 ).

[0135] Fig. 22 1 is a flowchart showing the needle inspection process SB2 of the embodiment. The needle inspection process SB2 includes a process of photographing the detection needle 3S of the inspection object at an arbitrary time. In the embodiment, the detection needle 3S is a reference needle 3R after use. That is, in the embodiment, the reference needle 3R and the detection needle 3S are the same needle 3. The first camera device 11 and the second camera device 12 each photograph the detection needle 3S held on the needle bar 4 at an arbitrary time.

[0136] The first image ID1 of the sewing needle 3S detected by the first imaging device 11 and the second image ID2 of the sewing needle 3S detected by the second imaging device 12 are obtained by the image obtaining unit 13A (step SB21 ).

[0137] The detection feature quantity calculation unit 13F calculates the first detection feature quantity based on the first image ID1 of the detection needle 3S held on the needle bar 4, and calculates the second detection feature quantity based on the second image ID2 of the detection needle 3S held on the needle bar 4 (step SB22).

[0138] Fig.23 1 is a diagram for explaining the detection feature quantity of the sewing needle 3 according to the embodiment. The detection feature quantity includes at least one of the first detection feature quantity and the second detection feature quantity. Fig.23 As shown, the detection feature quantities of the sewing needle 3 include: the length LS of the sewing needle 3S, the minimum width AS of the sewing needle 3S, the maximum width BS of the sewing needle 3S, the needle tip angle CS representing the angle of the front end of the sewing needle 3S, and the deformation amount DS of the bent and deformed sewing needle 3.

[0139] The inspection unit 13G compares the first detection feature quantity calculated by the detection feature quantity calculation unit 13F in step SB22 with the first reference feature quantity stored by the reference feature quantity storage unit 13E in step SB13, and compares the second detection feature quantity calculated by the detection feature quantity calculation unit 13F in step SB22 with the second reference feature quantity stored by the reference feature quantity storage unit 13E in step SB13 (step SB23).

[0140] The inspection unit 13G outputs inspection data indicating the inspection result of the sewing needle 3S based on the comparison result of step SB23 (step SB24).

[0141] In the embodiment, the inspection data outputted from the inspection unit 13G includes whether the bending of the detection needle 3S is detected, whether the front end of the detection needle 3S is blunted, and whether the bending deformation of the detection needle 3S is detected. In the case of blunting of the front end of the detection needle 3S, the inspection data outputted from the inspection unit 13G includes the amount of blunting of the detection needle 3S. In the case of bending deformation of the detection needle 3S, the inspection data outputted from the inspection unit 13G includes the deformation amount DS of the bending deformation of the detection needle 3S.

[0142] The inspection unit 13G can determine whether the detection needle 3S is bent by comparing the length LR stored in the reference feature quantity storage unit 13E with the length LS calculated by the detection feature quantity calculation unit 13F. When the difference between the length LS and the length LR is less than a predetermined length threshold, the inspection unit 13G determines that the detection needle 3S is not bent. When the difference between the length LS and the length LR is greater than the length threshold, the inspection unit 13G determines that the detection needle 3S is bent.

[0143] The inspection unit 13G can determine whether the tip of the detection needle 3S is blunted by comparing the needle tip angle CR stored in the reference feature storage unit 13E with the needle tip angle CS calculated by the detection feature calculation unit 13F. When the difference between the needle tip angle CS and the needle tip angle CR is below a predetermined angle threshold, the inspection unit 13G determines that the tip of the detection needle 3S is not blunted. When the difference between the needle tip angle CS and the needle tip angle CR is greater than the angle threshold, the inspection unit 13G determines that the tip of the detection needle 3S is blunted.

[0144] The inspection unit 13G can determine whether the detection needle 3S is bent or deformed by comparing the position of the needle reference axis NX stored in the calibration storage unit 13C with the position of the front end of the detection needle 3S calculated by the detection feature quantity calculation unit 13F. When the distance (deviation) between the position of the needle reference axis NX and the position of the front end of the detection needle 3S is less than a predetermined distance threshold, the inspection unit 13G determines that the detection needle 3S is not bent or deformed. When the distance (deviation) between the position of the needle reference axis NX and the position of the front end of the detection needle 3S is greater than the distance threshold, the inspection unit 13G determines that the detection needle 3S is bent or deformed.

[0145] Furthermore, when the inspection section 13G determines that the detection sewing needle 3S is bent and deformed, it is possible to calculate the deformation amount DS based on the distance (deviation amount) between the needle reference axis NX and the front end portion of the detection sewing needle 3S.

[0146] [Method for calculating characteristic quantities and inspection data]

[0147] An example of a method for calculating the above-mentioned feature quantities (reference feature quantities and detection feature quantities) is described below. A method for calculating the detection feature quantity by the detection feature quantity calculation unit 13F is described below. The method for calculating the reference feature quantity using the reference feature quantity calculation unit 13D is substantially the same as the method for calculating the detection feature quantity using the detection feature quantity calculation unit 13F. In addition, in the following description, a method for calculating the first detection feature quantity based on the first image ID1 by the detection feature quantity calculation unit 13F is described. The method for calculating the second detection feature quantity based on the second image ID2 by the detection feature quantity calculation unit 13F is substantially the same as the method for calculating the first detection feature quantity based on the first image ID1 by the detection feature quantity calculation unit 13F.

[0148] Fig.24 It is a diagram showing an example of the first image ID1 of the sewing needle 3 according to the embodiment. Fig.24 The first image ID1 shown is obtained by the first camera 11. The image obtaining unit 13A obtains the first image ID1 from the first camera 11.

[0149] Fig.25 and Fig.26 Each of them is a diagram showing an example of an image processing method of a first image according to an embodiment. Fig.25 As shown in FIG. 1 , the detection feature quantity calculation unit 13F performs edge extraction processing on the first image ID1. Thus, the outer shape of the sewing needle 3 is obtained. In addition, when the sewing needle 3 is hung with an upper thread, the extracted edge is discontinuous at the edge portion where the upper thread exists. When there is a discontinuous edge interval EA, the detection feature quantity calculation unit 13F can interpolate edge points in the discontinuous edge interval EA. By extracting the edge of the sewing needle 3, as shown in FIG. Fig.26 As shown, the detection feature quantity calculation unit 13F can calculate the length LS, the minimum width AS, and the maximum width BS.

[0150] In addition, the detection feature quantity calculation unit 13F sets a window in a predetermined area including the tip of the sewing needle 3 in the first image ID1, and performs fine edge extraction in the window. By performing fine edge extraction on the tip of the sewing needle 3, the detection feature quantity calculation unit 13F can calculate the needle tip angle CS.

[0151] [Calculation method of deformation amount of bent sewing needle]

[0152] Next, a method for calculating the actual deformation amount DS (DSA) of the sewing needle 3 that is bent and deformed will be described. Fig. 27 1 is a diagram showing an example of a method for calculating the deformation amount DS of the bent and deformed sewing needle 3 according to the embodiment. Fig. 27, the angle θ is the angle between the first optical axis AX1 and the second optical axis AX2. In the embodiment, the angle θ is 90[°]. The deformation amount DS in the first image ID1 is set as the deformation amount DSL, and the deformation amount DS in the second image ID2 is set as the deformation amount DSR. In addition, the actual deformation amount DS of the front end of the sewing needle 3 is set as the deformation amount DSA.

[0153] In addition, the sign of the bending direction of the sewing needle 3 is defined in the first image ID1. Fig. 27 As shown, a direction closer to the second optical axis AX2 than the first optical axis AX1 is set as a + direction, and a direction farther from the second optical axis AX2 than the first optical axis AX1 is set as a - direction.

[0154] Likewise, the sign of the bending direction of the sewing needle 3 is defined in the second image ID2. Fig. 27 As shown, a direction closer to the first optical axis AX1 than the second optical axis AX2 is set as a -direction, and a direction farther from the first optical axis AX1 than the second optical axis AX2 is set as a +direction.

[0155] Between the deformation amount DSA, the deformation amount DSL, the deformation amount DSR, and the angle θ, the following equations (1) and (2) hold. The equation (1) holds when the sign of the bending direction of the sewing needle 3 in the first image ID1 is the same as the sign of the bending direction of the sewing needle 3 in the second image ID2. The equation (2) holds when the sign of the bending direction of the sewing needle 3 in the first image ID1 is different from the sign of the bending direction of the sewing needle 3 in the second image ID2.

[0156]

Number 1

[0157] (DSA) 2 =(DSR) 2 +(DSL) 2 +2×DSR×DSL×cosθ…(1)

[0158]

Number 2

[0159] (DSA) 2 =(DSR) 2 +(DSL) 2 -2×DSR×DSL×cosθ…(2)

[0160] Thus, in the embodiment, the first camera 11 and the second camera 12 are arranged so that the first optical axis AX1 and the second optical axis AX2 are orthogonal to each other on the sewing needle 3, so when the sewing needle is bent and deformed, the deformation amount DSA can be calculated with high accuracy.

[0161] [Effect]

[0162] As described above, the first imaging device 11 and the second imaging device 12 are arranged so that the first optical axis AX1 and the second optical axis AX2 are orthogonal to each other on the sewing needle 3 , and therefore the sewing needle 3 can be inspected with high accuracy.

[0163] The sewing needle 3 is held on the needle bar 4 in a manner extending in the Zm axis direction orthogonal to the XmYm plane. The first optical axis AX1 and the second optical axis AX2 are parallel to the XmYm plane, respectively. Therefore, the processing device 13 can accurately determine whether there is bending deformation of the sewing needle 3. In addition, the processing device 13 can accurately calculate the deformation amount DS (DSA) of the bent and deformed sewing needle 3.

[0164] The first detection feature quantity and the first reference feature quantity are calculated based on the first image ID1 obtained by the first camera device 11. By comparing the first detection feature quantity and the first reference feature quantity, the state of the sewing needle 3 when observed from the first camera device 11 is calculated. The second detection feature quantity and the second reference feature quantity are calculated based on the second image ID2 obtained by the second camera device 12. By comparing the second detection feature quantity and the second reference feature quantity, the state of the sewing needle 3 when observed from the second camera device 12 is calculated. Since the state of the sewing needle 3 when observed from both the first camera device 11 and the second camera device 12 is calculated, the state of the sewing needle 3 can be determined with high accuracy.

Claims

1. A sewing needle inspection device, comprising: A first camera device for photographing a sewing needle held on a needle bar of a sewing machine; a second camera device for photographing the suture needle; and a processing device that outputs inspection data of the suture needle based on the first image obtained by the first camera device and the second image obtained by the second camera device, The first camera device and the second camera device are configured so that a first optical axis representing the optical axis of the first camera device and a second optical axis representing the optical axis of the second camera device are orthogonal to each other on the sewing needle. The sewing needle is held on the needle bar in a manner extending in a direction perpendicular to the predetermined surface. The first optical axis and the second optical axis are parallel to the predetermined plane, respectively, and the position of the first optical axis and the position of the second optical axis are substantially consistent in a direction perpendicular to the predetermined plane. The inspection data includes bending deformation of the suture needle, The processing device compares the position of the needle reference axis with the position of the front end of the suture needle calculated based on the first image and the second image to determine whether the bending deformation exists, wherein: The needle reference axis connects the center of the needle bar and the center of the needle hole through which the sewing needle can pass. The inspection data includes the deformation amount of the bent and deformed suture needle, Defining the sign of the bending direction of the suture needle in the first image, setting the direction closer to the second optical axis than the first optical axis as the + direction, and setting the direction farther from the second optical axis than the first optical axis as the - direction; The sign of the bending direction of the suture needle is defined in the second image, the direction closer to the first optical axis than the second optical axis is set as the - direction, and the direction farther from the first optical axis than the second optical axis is set as the + direction, The deformation amount in the first image is set as DSL, the deformation amount in the second image is set as DSR, the deformation amount of the front end of the suture needle is set as DSA, and the angle between the first optical axis and the second optical axis is set as θ, When the sign of the bending direction of the suture needle in the first image is the same as the sign of the bending direction of the suture needle in the second image, equation (1) holds; when the sign of the bending direction of the suture needle in the first image is different from the sign of the bending direction of the suture needle in the second image, equation (2) holds. (DSA) 2 =(DSR) 2 +(DSL) 2 +2×DSR×DSL×cosθ...(1) (DSA) 2 =(DSR) 2 +(DSL) 2 +2×DSR×DSL×cosθ...(2)。 2. The sewing needle inspection device according to claim 1, characterized in that: The processing device has: an image acquisition unit, which acquires the first image of the suture needle from the first camera device, and acquires the second image of the suture needle from the second camera device; a detection feature quantity calculation unit, which performs image processing on the first image obtained by the image obtaining unit to calculate a first detection feature quantity of the suture needle, and performs image processing on the second image obtained by the image obtaining unit to calculate a second detection feature quantity of the suture needle; A reference feature storage unit storing a first reference feature and a second reference feature of the sewing needle; as well as The inspection unit compares the first detection feature quantity with the first reference feature quantity and compares the second detection feature quantity with the second reference feature quantity to output the inspection data.

3. The sewing needle inspection device according to claim 2, characterized in that: The suture needles include a reference suture needle and a detection suture needle of the inspection object. The processing device has: a reference feature quantity calculation unit that calculates the first reference feature quantity based on the first image of the reference needle held on the needle bar, and calculates the second reference feature quantity based on the second image of the reference needle, The reference feature quantity storage unit stores the first reference feature quantity and the second reference feature quantity calculated by the reference feature quantity calculation unit.

4. The sewing needle inspection device according to claim 3, characterized in that: The reference needle and the detection needle are the same needle, The reference suture needle is a normal suture needle. The detection needle is the reference needle after use.

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