KR102573656B1 - Knitting machine and defect detection system - Google Patents

Abstract

(assignment)
The present invention provides a knitting machine capable of detecting defective knitting at an early stage and with high accuracy.
(solution)
The knitting machine of the present invention includes a knitting needle for knitting a fabric, a photographing unit 22 capable of photographing a stitch coupled to the knitting needle, and a state of the stitch photographed by the photographing unit 22 and when the stitch is normal. It has a judging unit that compares the stitch states of the stitches to determine whether the stitch is good or bad, and a position storage unit that stores the location of the stitch photographed by the photographing unit 22.

Description

Knitting machine and defect detection system {KNITTING MACHINE AND DEFECT DETECTION SYSTEM}

The present invention relates to a knitting machine capable of detecting defects in knitting of a knitted fabric and a technology of a defect detection system.

Conventionally, a technique for detecting a knitting defect for a knitted fabric is known. For example, it is as described in patent document 1.

Patent Document 1 discloses a technique for detecting the occurrence of defects (knitting defects) in a knitted fabric by comparing an image of a knitted fabric acquired using a photographing unit with an image of a normal knitted fabric previously stored in a storage device. has been

Japanese Unexamined Patent Publication No. 57-183469

However, since the technique described in Patent Literature 1 is configured to detect defects in the finished knitted fabric, unnecessary costs (power, yarn, knitting time, etc. required for the knitting machine that knits the knitted fabric) are incurred.

In addition, for knitted fabrics that shrink in the width direction, such as rib knit fabrics, it may be difficult to detect defects in the knitted fabric even by photographing the fabric.

The present invention has been made in view of the above situation, and an object to be solved is to provide a knitting machine capable of detecting a knitting defect at an early stage and with high accuracy and a defect detection system.

The problem to be solved by the present invention is as described above, and means for solving this problem will be described continuously.

That is, the knitting machine according to the present invention includes a knitting needle for knitting a fabric, a photographing unit capable of photographing stitches coupled to the knitting needle, and a normal person based on the state and knitting data of the stitch photographed by the photographing unit and a judging unit that compares the state of the stitches at the time and judges whether or not the stitch is good or bad, and a position storage unit that stores the position of the stitch photographed by the photographing unit.

By configuring in this way, a knitting defect can be detected at an early stage and with high accuracy.

In addition, the knitting needles are disposed on needle beds disposed to face each other with a needle bed gap interposed therebetween, and the photographing unit is coupled to the knitting needles from above the needle bed gap of the needle beds disposed to face each other. You may also photograph stitches.

With this configuration, it is easy to photograph stitches, and consequently, defective knitting can be detected with high accuracy.

Further, the photographing unit may photograph the stitches engaged with the knitting needles provided on the other side from one side of the needle beds arranged to face each other.

With this configuration, it becomes easier to photograph stitches, and it is possible to detect knitting defects with higher precision.

In addition, the photographing unit may be installed so as to be movable along the needle bed.

With this structure, it is possible to photograph stitches in a plurality of places with one photographing unit.

In addition, the photographing unit may be fixed at a position where a stitch coupled to the knitting needle can be photographed, and the stitch may be photographed in association with stitch formation timing by the knitting needle.

By configuring in this way, the simplification of the structure can be achieved. Also, images of stitches can be acquired at an appropriate timing.

In addition, the defect detection system according to the present invention includes a photographing unit capable of photographing a stitch coupled to a knitting needle for knitting a knitted fabric, and a state of the stitch photographed by the photographing unit and a normal state based on knitting data. A determination unit for comparing stitch states to determine whether a stitch is good or bad, and a position storage unit for storing the location of the stitch photographed by the photographing unit are provided.

By configuring in this way, a knitting defect can be detected at an early stage and with high accuracy.

As an effect of the present invention, it is possible to obtain an effect that a knitting defect can be detected at an early stage and with high accuracy.

1 is a front view showing the overall configuration of a flat knitting machine according to one embodiment of the present invention.
Fig. 2 is a side view showing the configuration of a needle bed and a carriage.
Fig. 3 is a plan view showing the configuration of a needle bed and a carriage.
Fig. 4 is a block diagram showing a configuration related to control of a flat knitting machine.
Fig. 5 is a schematic plan view schematically showing a cam mechanism installed in the carriage.
Fig. 6 is a schematic plan view of the carriage showing the arrangement of the photographing unit and the lighting unit.
In Fig. 7, (a) is a plan view showing the configuration of the imaging unit, and (b) is a side view thereof.
Fig. 8 is a partial cross-sectional view of a plane showing the configuration of a lighting unit.
Fig. 9 is a plan view showing the relative positional relationship between the photographing unit and the lighting unit.
In Fig. 10, (a) is a diagram showing an imaging unit that moves when the carriage moves in a rightward direction, and (b) is a diagram showing an imaging unit that moves when the carriage moves in a leftward direction.
Fig. 11 is a schematic diagram showing the processing of the control unit when organizing each course.
Fig. 12 is a diagram showing an example of an image captured by a photographing unit and a normal image.
In Fig. 13, (a) is a diagram showing an example of disposing the imaging unit below the needle bed, and (b) is a diagram showing an example of disposing the imaging unit above and below the needle bed.

Hereinafter, directions indicated by arrows U, arrow D, arrow F, arrow B, arrow L, and arrow R in the drawings are defined as upward, downward, forward, backward, leftward, and rightward directions, respectively. In addition, in each drawing, for convenience of description, showing some members in the drawings may be appropriately omitted.

First, the overall configuration of a flat knitting machine 1 according to an embodiment of the present invention will be described.

1 to 4, the flat knitting machine 1 largely includes a needle bed 10, a carriage 20, a yarn guide rail 30, a servo motor ( 40), a thread raising stand 50 and a control unit 60.

The needle beds 10 shown in Figs. 1 to 3 are arranged so as to face each other in the front and rear with the needle bed gap S therebetween. The front and rear needle beds 10 are arranged so as to incline upward toward the front and rear center sides (sides facing each other), that is, in an inverted V shape when viewed from the side (see Fig. 2). Each needle bed 10 is provided with a plurality of knitting needles 11 arranged along the longitudinal direction (left-right direction) of the needle bed 10 . The front and rear needle beds 10 can relatively move left and right when stitches are exchanged with each other.

The carriages 20 are arranged as a pair of front and rear so as to face each other from above with respect to the front and rear needle beds 10 . The front and rear carriages 20 are connected by a bridge 20a arranged so as to span a plurality of yarn guide rails 30 . The carriage 20 may reciprocate along the longitudinal direction of the needle bed 10 by means of the servo motor 40 (see FIG. 4). The carriage 20 is provided with a needle mechanism (not shown) and a cam mechanism 21 for selectively operating the knitting needles 11 of the needle bed 10 . In addition, a photographing unit 22 and a lighting unit 23 are installed in the carriage 20 to photograph the stitches coupled to the knitting needles 11 .

The yarn guide rails 30 shown in FIGS. 1 and 2 are arranged in plurality so as to extend along the longitudinal direction of the needle bed 10 above the needle bed gap S. On the yarn guide rail 30, a yarn carrier 31 (see Fig. 1) for supplying the knitting yarn Y is movably supported.

A yarn cone 51 around which a knitting yarn Y is wound is installed on the yarn raising stand 50 shown in FIG. 1 . The knitting yarn Y from the yarn con 51 is fed to the yarn carrier 31 through an appropriate yarn feeding route.

The controller 60 shown in FIG. 4 is for controlling the operation of the flat knitting machine 1. The control unit 60 includes an arithmetic processing unit such as a CPU, a storage unit such as RAM or ROM, and the like. In the storage unit of the control unit 60, various information, programs, and the like used to control the flat knitting machine 1 are stored. The control unit 60 is installed in a suitable location of the flat knitting machine 1 (for example, inside the main body of the flat knitting machine 1 (below the back needle bed 10)).

The controller 60 is connected to the servomotor 40 and can control the operation of the servomotor 40 . The control unit 60 may arbitrarily move the carriage 20 by controlling the operation of the servo motor 40 . Also, the control unit 60 can detect the position of the carriage 20 based on the number of rotations of the servomotor 40 .

In addition, the controller 60 is connected to the carriage 20 (more specifically, the cam mechanism 21, the photographing unit 22, and the lighting unit 23), and can control the operation of the carriage 20.

The control unit 60 controls each unit of the flat knitting machine 1 based on knitting data or the like created in advance. Specifically, the controller 60 may reciprocate the carriage 20 along the longitudinal direction of the needle bed 10 by controlling the operation of the servo motor 40 . At this time, the knitting needle 11 is moved forward and backward with respect to the needle bed gap S by the cam mechanism 21 mounted on the carriage 20, thereby performing knitting operations such as knit, tuck, and miss. Stitches can be exchanged between the front and rear needle beds 10. By repeating the reciprocating movement of the carriage 20, the knitted fabric K is knitted.

Also, the control unit 60 may photograph the stitch coupled to the knitting needle 11 by the photographing unit 22 . The control unit 60 can detect a knitting defect based on the image (stitch shape) captured by the photographing unit 22 .

Hereinafter, the configuration of the carriage 20 will be described in more detail.

Hereinafter, among the front and rear needle beds 10, the front needle bed 10 may be referred to as a front needle bed 10F, and the rear needle bed 10 may be referred to as a rear needle bed 10B, respectively. Hereinafter, among the front and rear carriages 20, the front carriage 20 may be referred to as a front carriage 20F, and the rear carriage 20 may be referred to as a rear carriage 20B, respectively.

First, the configuration of the cam mechanism 21 will be described with reference to FIG. 5 .

As shown in Fig. 5, three cam mechanisms 21 for advancing and retracting the knitting needles 11 are provided on the front carriage 20F. Specifically, the first transfer cam mechanism 21A, the knit cam mechanism 21B, and the second transfer cam mechanism 21C are disposed along the movement direction (left and right direction) of the carriage 20 .

The knit cam mechanism 21B is for forming stitches using the knitting yarn Y supplied from the yarn carrier 31. The first transfer cam mechanism 21A and the second transfer cam mechanism 21C are for transferring between the knitting needles 11 of the front and rear needle beds 10. In this embodiment, the first transfer cam mechanism 21A, the knit cam mechanism 21B, and the second transfer cam mechanism 21C are arranged in order from left to right.

Each cam mechanism 21 can advance and retreat the knitting needle 11 by guiding the butt of the knitting needle 11 selected based on the knitting data along the advancing and retreating trajectory L. In this way, it is possible to form or transfer stitches using the knitting yarn Y.

For example, in the present embodiment, as indicated by arrows in Fig. 5, when the carriage 20 moves rightward, the knit cam mechanism 21B acts as an advance system to form stitches. Also in this case, the first transfer cam mechanism 21A serves as a follow-up system, and transfers stitches formed by the knit cam mechanism 21B. Also in this case, the second transfer cam mechanism 21C does not transfer.

Conversely, when the carriage 20 moves leftward, the cam mechanism 21B for knitting becomes a preceding system and forms stitches. Also in this case, the second transfer cam mechanism 21C serves as a follow-up system, and transfers stitches formed by the knit cam mechanism 21B. Also in this case, the first transfer cam mechanism 21A does not transfer.

However, the operation of each of these cam mechanisms 21 is only an example, and it is also possible to sequentially perform transfer, stitch formation, and transfer using the three cam mechanisms 21, for example.

Also, the front carriage 20F has been described using FIG. 5, but as shown in FIG. 6, the rear carriage 20B has a configuration substantially symmetrical with the front carriage 20F (similarly to the front carriage 20F, the second carriage 20B has Since it is a configuration provided with one transfer cam mechanism 21A, etc.), detailed description is omitted.

Next, the configuration of the photographing section 22 will be described using FIG. 7 .

As shown in Fig. 7, the photographing unit 22 largely includes a support member 22a, a camera 22b, a central prism 22c, and a side prism 22d.

The support member 22a supports the camera 22b, the central prism 22c, and the side prism 22d. The support member 22a is formed of a plate-like member. The support member 22a is formed in an appropriate shape so as to support the camera 22b, the central prism 22c and the side prism 22d at a predetermined position.

The camera 22b is a device for acquiring images. The camera 22b is fixed to the support member 22a with the lens 22e facing in a predetermined direction.

The central prism 22c guides light from two directions to the lens 22e of the camera 22b. The central prism 22c is disposed in front of the lens 22e (in the direction in which the lens 22e faces). The central prism 22c reflects light from the side (in the vertical direction of the paper in Fig. 7(a)) and guides it to the lens 22e.

The side prism 22d guides light from a predetermined direction to the central prism 22c. Side prisms 22d are provided as a pair (one pair in the vertical direction of the paper in Fig. 7(a)) with the center prism 22c interposed therebetween. The side prisms 22d reflect light from the front side (right side of the paper in Fig. 7(a)) and guide it to the central prism 22c.

In the photographing unit 22 configured as described above, light from the front of the pair of lateral prisms 22d is appropriately guided to the lateral prisms 22d and the central prism 22c, and the lens 22e of the camera 22b ) is entered into. In this way, the photographing unit 22 can acquire images of two different locations (front faces of the two lateral prisms 22d) with one camera 22b.

Next, the arrangement of the photographing unit 22 will be described using FIGS. 2 and 6 .

As shown in FIGS. 2 and 6 , the photographing unit 22 is disposed above the needle bed gap S of the needle bed 10 . A total of four photographing units 22 are installed in the front and rear carriages 20 . Specifically, the photographing units 22 are disposed two by one in front and behind with the needle bed gap S interposed therebetween. The photographing unit 22 is directly or indirectly fixed to the carriage 20 (through a bridge 20a or other suitable member). By attaching the photographing unit 22 to the moving carriage 20, since it is possible to photograph while moving the photographing unit 22 together with the carriage 20, for example, a plurality of locations by a single photographing unit 22 can be filmed.

Paying attention to the two photographing parts 22 disposed in front of the needle bed gap S, the photographing parts 22 are disposed above the front carriage 20F. The photographing unit 22 is arranged so that the photographing direction (lens 22e) faces backward and downward. Accordingly, the photographing unit 22 can photograph the front end of the knitting needle 11 of the back needle bed 10B (more specifically, the stitch coupled to the knitting needle 11). .

By photographing the knitting needles 11 of the rear needle bed 10B in this way from above the needle bed gap S, it is easy to clearly photograph the shape of the stitch. In particular, as in the present embodiment, by taking a picture from the side of the front needle bed 10F facing the knitting needle 11 of the back needle bed 10B, it becomes easier to take a picture of the shape of the stitch more clearly, and furthermore, it is easier to take a picture of the knitting needle 11 described later. Defects can be detected with high accuracy.

Also, the two photographing units 22 disposed in front of the needle bed gap S are disposed to correspond to positions of the cam mechanism 21 in the left-right direction. Specifically, as shown in Fig. 6, the photographing unit 22 is arranged so as to be at substantially the same position as the first transfer cam mechanism 21A and the second transfer cam mechanism 21C in the left-right direction. In addition, the side prisms 22d of each photographing unit 22 are arranged to be positioned on the left and right sides of the cam mechanism 21, respectively.

As a result, as shown in FIG. 6, the two imaging parts 22 have four imaging points in the back needle bed 10B (first rear imaging point PB1, second rear imaging point PB2, and rear third imaging point PB2). A photographing point PB3 and a fourth photographing point PB4) may be photographed.

The rear first shooting point PB1 is set to be located leftward from the first transfer cam mechanism 21A. Further, the rear second shooting point PB2 is set to be located in the rightward direction from the first transfer cam mechanism 21A and leftward from the knit cam mechanism 21B. Further, the rear third shooting point PB3 is set to be located in the rightward direction from the knit cam mechanism 21B and the leftward direction from the second transfer cam mechanism 21C. Further, the rear fourth shooting point PB4 is set to be located in the rightward direction from the second transfer cam mechanism 21C.

In addition, in the two photographing parts 22 disposed behind the needle bed gap S, since they are arranged symmetrically with the photographing parts 22 disposed in front with the needle bed gap S interposed therebetween, omit explanation. As shown in FIG. 6, the two imaging parts 22 disposed behind the needle bed gap S are four imaging points (first front imaging point PF1, front second imaging point PF1) in the front needle bed 10F, as shown in FIG. A photographing point PF2, a front third photographing point PF3, and a front fourth photographing point PF4) may be photographed.

Since the left and right positions of the front four imaging points PF1 to PF4 are the same as those of the rear four imaging points PB1 to PB4, detailed descriptions are omitted.

As described above, in this embodiment, it is possible to shoot a total of eight shooting points using the four shooting units 22 .

Next, the configuration of the lighting unit 23 will be described using FIG. 8 .

As shown in Fig. 8, the lighting unit 23 largely includes an LED 23a, a condensing lens 23b, and a guide unit 23c.

The LED 23a is a light source that emits light when a voltage is applied. The LED 23a can emit light in a predetermined direction (rightward direction of the paper in FIG. 8).

The condensing lens 23b is for condensing the light irradiated from the LED 23a. The condensing lens 23b is disposed in front of the LED 23a (right side of the page in Fig. 8). In this embodiment, two condensing lenses 23b are arranged.

The guide portion 23c guides the light emitted from the LED 23a to a predetermined position. The guide portion 23c is made of a light-transmitting material (such as acryl). The guide portion 23c is formed in a rectangular shape extending along the irradiation direction of the light from the LED 23a (left-right direction of the paper in FIG. 8). The front end face 23d of the guide portion 23c (the face of the end portion on the opposite side to the LED 23a) is formed in the shape of an inclined plane cut so as to be inclined. Specifically, the front end surface 23d is formed to be inclined with respect to a direction perpendicular to the longitudinal direction of the guide portion 23c.

In the lighting unit 23 configured as described above, when light is irradiated from the LED 23a, the light penetrates the guide unit 23c through the condensing lens 23b. The light penetrating the guide portion 23c advances along the longitudinal direction of the guide portion 23c and is irradiated to the outside of the guide portion 23c from the front end surface 23d. When light is irradiated from the front end surface 23d, the light is refracted at an angle corresponding to the inclination angle of the front end surface 23d.

Next, the arrangement of the lighting unit 23 will be described using FIGS. 2 and 6 .

As shown in FIGS. 2 and 6 , a total of eight lighting units 23 are installed in the carriage 20 . Specifically, four lighting units 23 are disposed in front and behind with the needle bed gap S interposed therebetween. The lighting unit 23 is directly or indirectly fixed to the carriage 20 (through a bridge 20a or other suitable member).

Paying attention to the four lighting units 23 disposed in front of the needle bed gap S, the lighting units 23 are arranged so that the light irradiation direction (the front end surface 23d of the guide unit 23c) faces downward to the rear. are placed Accordingly, the lighting unit 23 can irradiate light to the front end portion of the knitting needle 11 of the rear needle bed 10B (more specifically, the stitch coupled to the knitting needle 11).

In addition, the four lighting units 23 disposed in front of the needle bed gap S are arranged to emit light to the four imaging points PB1 to PB4 of the needle bed 10B at the rear.

In addition, in the four lighting units 23 disposed behind the needle bed gap S, since they are disposed symmetrically with the lighting units 23 disposed in front with the needle bed gap S interposed therebetween, the detailed description is omit As shown in FIG. 6, the four lighting units 23 disposed behind the needle bed gap S are disposed so as to emit light to the four imaging points PF1 to PF4 of the front needle bed 10F. do.

The relative positional relationship between the photographing unit 22 and the lighting unit 23 will be described below with reference to FIG. 9 .

9 shows, as an example, the photographing unit 22 for photographing the front first photographing point PF1 and the front second photographing point PF2, the front first photographing point PF1 and the front second photographing point PF2. ) shows two lighting units 23 for irradiating light.

As shown in Fig. 9, each lighting unit 23 is disposed on the side of the field of view of the imaging unit 22, and irradiates light to each imaging point. As described above, the front end surface 23d of the lighting unit 23 is formed so as to refract the light irradiated from the guide unit 23c. In this embodiment, each lighting unit 23 is arranged so that light is refracted toward each imaging point. Accordingly, the lighting unit 23 can be disposed outside the field of view of the imaging unit 22 (outside the field of view), and it is possible to prevent the lighting unit 23 from interfering with photography of the imaging unit 22 .

In the flat knitting machine 1 structured as described above, the control unit 60 determines whether a stitch is good or bad based on the image of the stitch photographed by the photographing unit 22, so that defective knitting can be detected. there is. A method for detecting a mismatch by the controller 60 will be described below.

The control unit 60 performs photography by the photographing unit 22 in synchronization with the reciprocating movement of the carriage 20 during knitting of the knitted fabric K. Specifically, the control unit 60 controls the light from the lighting unit 23 toward the stitch coupled to the knitting needle 11 when the knitting needle 11 to be photographed reaches the photographing point due to the movement of the carriage 20. In addition to being irradiated, the corresponding stitch is photographed by the photographing unit 22 . Since the control unit 60 can grasp the position of the carriage 20 from the number of revolutions of the servomotor 40, it is possible to take pictures at an accurate timing according to the position of the stitch (knitting needle 11). The controller 60 photographs all knitting needles 11 (stitches) during knitting. Also at this time, the controller 60 memorizes the position of the photographed stitch.

Here, for example, as shown in Fig. 10(a), when the carriage 20 moves rightward, stitches are formed by the knitting cam mechanism 21B, which is the preceding system, and the first system, which is the following system, is formed. The transfer is performed by the transfer cam mechanism 21A. That is, in this case, it is the knitting needle 11 after passing through the knit cam mechanism 21B and the knitting needle 11 after passing through the first transfer cam mechanism 21A that may cause knitting defects. .

So, when the carriage 20 moves in the right direction, the control unit 60 sets the front first shooting point PF1, the front second shooting point PF2, the rear first shooting point PB1 and the rear second shooting point PF1. Only the four imaging points of the imaging point PB2 are captured. That is, when the carriage 20 moves rightward, the controller 60 photographs stitches using only the two photographing units 22 disposed on the left side.

Conversely, as shown in Fig. 10(b), when the carriage 20 moves leftward, stitches are formed by the cam mechanism 21B for knitting, which is the preceding system, and the cam mechanism for second transfer, which is the following system ( 21C) transfer is made. That is, in this case, it is the knitting needle 11 after passing through the knit cam mechanism 21B and the knitting needle 11 after passing through the second transfer cam mechanism 21C that may cause knitting defects. .

So, when the carriage 20 moves in the left direction, the control unit 60 controls the front third shooting point PF3, the front fourth shooting point PF4, the rear third shooting point PB3, and the rear fourth shooting point. Only the four imaging points of the imaging point PB4 are photographed. That is, when the carriage 20 moves leftward, the control unit 60 photographs stitches using only the two photographing units 22 disposed on the right side.

However, this control of the photographing unit 22 is only an example, and all photographing points may be photographed using all four photographing units 22, for example. In this case, the burden of processing by the control unit 60 can be reduced by determining the quality of only appropriately necessary images instead of determining the quality of all captured images.

In this way, as shown in Fig. 11, the controller 60 photographs all the stitches of each course while knitting the knitted fabric K, and also memorizes the positions of the photographed stitches.

Also, when knitting each course, the control unit 60 determines the quality of the stitches of one course before. A method for judging the quality of a stitch will be described below.

12 shows an example of an image P of stitches captured by the photographing unit 22. As shown in FIG. Fig. 12 shows an example of an image P obtained by photographing the front first shooting point PF1 and the front second shooting point PF2.

First, the control unit 60 extracts an area (judgment area R) representing a stitch to be subjected to judgment from each of the front first and second front shooting points PF1 and PF2. At this time, the control unit 60 can extract an appropriate judgment area R based on the information of the image P. For example, the tip value of the knitting needle 11 can be detected based on the luminance of the image P, and the judgment area R can be extracted based on the tip position of the knitting needle 11.

Next, the controller 60 compares the shape of the stitch appearing in the judgment area R (actually photographed) with the shape of the stitch stored in advance as normal, and judges whether the stitch is good or bad.

For example, in the controller 60, an image (normal image N) representing the shape of a stitch in normal condition is stored in advance. In addition, the shape of the stitch in normal condition is the type of stitch (knit, miss, tuck, etc.), type of knitting yarn (Y), adjacent stitches (for example, stitches formed up to the previous course, type of left and right stitches, etc.) presence or absence), etc. Therefore, in the control unit 60, a large number of normal images N of various patterns are stored in advance.

Based on the knitting data of the currently knitted fabric K and the position of the captured stitch, the control unit 60 considers the type of stitch, the type of knitting yarn Y, adjacent stitches, etc. The shape of a stitch estimated to be coupled to the knitting needle 11 is determined. Then, the control unit 60 extracts a normal image N suitable for quality determination (corresponding to the photographed stitch shape) from various normal images N stored therein, and uses it for the quality determination of the stitch.

The control unit 60 performs image processing using the image in the judgment area R and the normal image N to determine the quality of the stitch. For example, the control unit 60 calculates the degree of similarity between the shape of the stitch in the judgment area R and the shape of the stitch shown in the normal image N, and when the degree of similarity is high to some extent (more than a predetermined threshold value), the judgment is made. It can be determined that the stitches in the region R are normal.

On the other hand, the controller 60 may determine that the stitches in the judgment area R are abnormal when the degree of similarity is low to some extent (less than a predetermined threshold value). As stitch abnormalities, various states such as the knitting yarn Y being broken, stitches (loops) not being formed, and stitches being excessively contracted are assumed.

In addition, judgment of whether a stitch is good or bad (comparison of stitch shapes) can be performed by comparing the RGB values, luminance, etc. of the judgment area R and the normal image N. Further, when a core line (a line passing through the center of the knitting yarn Y) of the knitting yarn Y forming the stitch is extracted from the image, for example, without using luminance or the like, and the shape of the core line is normal. The quality of stitches can also be determined by comparing the shapes of the core wires (calculating the degree of similarity).

The control unit 60 promptly determines the quality of the stitches after capturing the image P as described above. Specifically, as shown in Fig. 11, the control unit 60 executes pass/fail determination of an image captured in a certain course (e.g., N course) while organizing the next course (N+1 course). Accordingly, when a defect occurs in a stitch, the defect can be detected immediately thereafter (during knitting of the next course).

For example, as shown in Fig. 11, when a stitch defect occurs in knitting the N+3 course, the stitch defect of the N+3 course can be detected during knitting of the N+4 course. When a stitch defect is detected, the control unit 60 can quickly stop the operation of the carriage 20 to stop knitting by the flat knitting machine 1. The timing of the stitch pass/fail judgment is not limited to this, and for example, pass/fail judgment of an image captured in a certain course can be executed in real time while the course is being organized.

In addition, the controller 60 stores the position where the defect was detected (the position of the knitting needle 11). The position can be grasped based on the position of the carriage 20 when the image P is acquired. By memorizing the location, it is possible to grasp not only whether or not a defect has occurred but also the location of the defect.

In addition, the controller 60 can display an image of a stitch at a position where a defect is detected (or a defect is suspected) on a display unit such as a monitor so that an operator can check it.

As described above, in the present embodiment, a stitch in a state of engagement with the knitting needle 11 is photographed, and defects can be detected from the photographed image. That is, since the presence or absence of a defect can be grasped during knitting of the knitted fabric K, a knitting defect can be detected at an early stage. Accordingly, it is possible to promptly respond to interruption of knitting, and suppress unnecessary costs (electric power required for flat knitting machine 1 for knitting knitted fabric K, knitting yarn Y, knitting time, etc.) there is.

In addition, by determining whether the shape of each stitch in a state coupled to the knitting needle 11 is judged not to be good or bad, rather than to judge the quality of the knitted fabric K after knitting, the shape of each stitch can be confirmed more accurately, and furthermore, can detect defects with high accuracy. In particular, defects in knitted fabrics (rib knitted fabrics, knitted fabrics using stretch yarns, etc.), which are difficult to confirm in the state of knitted fabrics, can be detected with high accuracy.

The control unit 60 according to this embodiment is one embodiment of the determination unit and location storage unit according to the present invention.

Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and appropriate changes are possible within the scope of the technical idea of the invention described in the claims.

For example, in the present embodiment, the flat knitting machine 1 is cited as an example of the knitting machine, but the present invention is not limited to this, and various other knitting machines (eg, circular knitting machines, warp knitting machines ( warp knitting machine), etc.). That is, it is possible to detect defects in knitting by providing a photographing unit capable of photographing stitches coupled to knitting needles of various knitting machines.

Also, the image captured by the photographing unit 22 can be used for purposes other than detection of defective knitting. For example, the generally knitted fabric K is pulled down by a take-down roller or the like, and the control of the take-down roller (control of tension for pulling down the knitted fabric K) causes the image to be drawn. can also be used

Specifically, when the tension for the pull of the takedown roller is weak, the knitted fabric K floats in the needle bed gap S. Therefore, whether or not the knitted fabric K is floated is determined from the image captured by the photographing unit 22, and if the knitted fabric K is floated, the tension for pulling the takedown roller is increased. In this way, occurrence of defects can be suppressed. Further, when it is judged that a defect has obviously occurred due to the floating of the knitted fabric K, the flat knitting machine 1 can be stopped. In addition, the flat knitting machine 1 can be stopped even when it is judged that a defect is clearly occurring due to the rise of the raw fabric or the like.

In this embodiment, an example in which the imaging unit 22 is installed on the carriage 20 has been shown, but the present invention is not limited to this and the arrangement of the imaging unit 22 is not limited. For example, it is also possible to install on a movable body installed separately from the carriage 20 (a movable body capable of moving along the longitudinal direction of the needle bed 10). For example, it is also possible to install the photographing unit 22 on a movable body capable of moving along the yarn guide rail 30 .

In the present embodiment, the photographing unit 22 is configured to be movable, but the present invention is not limited to this, and it is also possible to arrange (fix) in a non-movable state. For example, the photographing unit 22 can be fixed at a position where stitches can be photographed, such as above the needle bed gap S. In this case, the entire range of the needle bed 10 in the longitudinal direction may be photographed with one photographing unit 22, or may be photographed at a plurality of locations using a plurality of photographing units 22.

In addition, when the photographing unit 22 is fixed, it is preferable to photograph the stitches by the photographing unit 22 in association with the stitch forming timing by the knitting needle 11 . Specifically, as described in the above embodiment, it is preferable to photograph the knitting needle 11 after passing through the preceding system and the following system by interlocking the photographing timing with the position of the carriage 20.

By fixing the photographing unit 22 in this way, since a mechanism for movement becomes unnecessary, the configuration can be simplified. In addition, by photographing the stitches in association with the timing of stitch formation by the knitting needle 11, an image of the stitches can be obtained at an appropriate timing (after completion of knitting).

In the present embodiment, the photographing unit 22 is disposed above the carriage 20 and the stitches are photographed from above the needle bed 10, but the present invention is not limited to this. For example, as shown in Fig. 13(a), the photographing section 22 may be disposed below the needle bed 10, and the stitches may be photographed from below the needle bed 10.

Further, as shown in FIG. 13(b), it is also possible to arrange the photographing units 22 above and below the needle bed 10, respectively, and to photograph stitches from both the upper and lower sides of the needle bed 10. . By photographing the same stitch in a plurality of directions according to this configuration, the shape of the stitch can be grasped more accurately, and defect detection accuracy can be improved.

Also in the lighting unit 23, as in the photographing unit 22, it is possible to install it on a movable body other than the carriage 20. It is also possible to arrange (fix) the lighting unit 23 in an immovable state. It is also possible to arrange the lighting unit 23 below (or both above and below) the needle bed 10 to irradiate light from below the needle bed 10 toward the stitches. In addition, it is also possible to install the lighting unit 23 on the outside of the carriage 20 and install a suitable reflective member (mirror, etc.) on the carriage 20 to guide the light irradiated outside the carriage 20 to a desired shooting location. do.

In addition, the type (color or intensity) of light irradiated by the lighting unit 23 may be appropriately adjusted according to the type or color of the knitting yarn Y.

It is also possible to use not only an image obtained by actually photographing a normal stitch, but also an image created by machine learning, for example, of images of a large number of normal stitches as the normal image N for judging the quality of a stitch. In this way, it becomes possible to make a more appropriate quality/failure determination. Further, in this case, it is also possible to further study images of stitches photographed by the photographing unit 22 during knitting by the flat knitting machine 1, and update the normal image N at any time.

Also, as the normal image N, it is also possible to use an image created by combining a stitch shape obtained by 3D simulation and a thread image.

Further, in the present embodiment, an example in which pass/fail determination is made based on the shape of a stitch has been shown, but the present invention is not limited to this. For example, the control unit 60 may determine the type of stitch captured and compare the type information obtained from the knitting data to determine pass/fail of the stitch. The control unit 60 can also determine the quality of a stitch by determining the degree of similarity between the image of the photographed stitch and the image of the normal stitch. In this way, the control unit 60 can determine whether a stitch is good or bad by appropriately comparing all states (shape, type, etc.) of the photographed stitch and the normal stitch.

In the present embodiment, an example in which the controller 60 stores the location where a defect is detected has been shown, but the present invention is not limited to this. For example, it is also possible to store the location where a defect is detected in an RFID (ID tag) formed on the knitted fabric K or a server that manages information on the knitted fabric K.

In this embodiment, an example of quickly stopping the flat knitting machine 1 when a defect is detected has been shown, but the present invention is not limited to this. For example, even if a defect is detected, knitting continues without stopping the flat knitting machine 1, and after knitting of the knitted fabric K is completed, the defect location can be confirmed. In addition, if there is a stitch that cannot be completely judged as defective, and it is difficult to determine the quality, the position is stored in the control unit 60 or the like, so that the operator can visually check after knitting of the knitted fabric K is completed. may be

In addition to the stitch quality determination as in the present embodiment, it is also possible to determine the quality of the knitted fabric K. For example, an imaging unit different from the imaging unit 22 of the present embodiment is provided below the needle bed 10 to photograph the knitted fabric K. In addition, an image of the knitted fabric K at a place suspected of being defective can be displayed on the display unit to be checked by the operator, or the control unit 60 can automatically determine the quality of the knitted fabric K. By combining the stitch quality determination and the knit fabric K determination in this way, defects that cannot be completely judged only by the stitch quality determination alone can be detected from the image of the knitted fabric K, or the quality of the knit fabric K Defects that can only be detected in images (oil stains, stains, etc.) can be detected.

Furthermore, by acquiring stitch images as in the present embodiment, it is possible not only to detect a defect but also to specify the cause of the defect. Specifically, when a stitch defect is detected, the cause of the defect can be specified by checking the image. For example, when the knitting yarn Y is broken, the tension of the knitting yarn Y is too high, or when no stitches are formed, the cause of the knitting needle 11 is damaged, etc. It becomes possible to specify (estimate) .

Further, in this embodiment, an example in which a pair (two sheets) of needle beds 10 are provided is shown, but the number of needle beds 10 is not limited to this. For example, before and after the needle bed gap S, it is also possible to install the needle beds 10 two at a time (a total of four).

In addition, the cam mechanism 21 shown in this embodiment is only an example, and the configuration (number, arrangement, operation, etc.) of the cam mechanism 21 can be arbitrarily changed. In addition, the present invention can also be applied to a carriageless knitting machine in which the knitting needle is driven forward and backward by a separate actuator without the cam mechanism 21.

Further, in the present embodiment, a configuration for detecting the position of the carriage 20 based on the number of revolutions of the servomotor 40 has been exemplified, but the present invention is not limited to this, and the position of the carriage 20 (and furthermore, An appropriate sensor for detecting the imaged stitch (the position of the knitting needle 11) may be installed separately.

Also, in the present embodiment, an example in which various controls and defects are detected by the control unit 60 provided in the flat knitting machine 1 has been shown, but the present invention is not limited to this. That is, some or all of the functions of the control unit 60 may be executed by a control unit installed separately from the flat knitting machine 1 (for example, a personal computer, etc.). For example, it is also possible to perform stitch pass/fail determination by a PC installed outside the flat knitting machine 1.

In this embodiment, an example has been shown in which the flat knitting machine 1 (the control unit 60 provided in the flat knitting machine 1) has a function of detecting defects, but the present invention is not limited to this. That is, the present invention can be applied not only to a knitting machine, but also to a defect detection system for detecting defects in a knitted fabric knitted by the knitting machine. For example, in this case, the defect detection system includes: a photographing unit capable of photographing a stitch in a state in which it is attached to a knitting needle; a judging unit that determines whether a stitch is good or bad from the shape of a stitch photographed by the photographing unit; and the location of the photographed stitch. It is good if it is provided with the location memory which memorizes. Such a defect detection system can be easily applied to an existing knitting machine by appropriately installing a photographing unit in the knitting machine.

1: flat knitting machine
10: needle bed
11: knitting needle
20: Carriage
21: cam mechanism
22: filming unit
23: lighting unit
60: control unit

Claims (6)

A knitting needle for knitting knitted fabric;
A photographing unit capable of photographing a stitch coupled to the knitting needle;
a judging unit which compares a stitch state photographed by the photographing unit with a stitch state when normal based on knitting data , and judges whether the stitch is good or bad;
A position storage unit for storing the position of the stitch photographed by the photographing unit
Organizing machine provided.
According to claim 1,
The needle is
Each is disposed on needle beds arranged to face each other with a needle bed gap interposed therebetween,
the filming unit,
Photographing the stitches coupled to the knitting needles from above the needle bed gap of the needle beds arranged to face each other
organizer.
According to claim 2,
the filming unit,
Taking pictures of stitches engaged with the knitting needles installed on the other side from one side of the needle beds arranged to face each other
organizer.
According to claim 2 or 3,
the filming unit,
Installed to move along the needle bed
organizer.
According to any one of claims 1 to 3,
the filming unit,
Fixed at a position where a stitch coupled to the knitting needle can be photographed, and photographing the stitch in association with the formation timing of the stitch by the knitting needle
organizer.
A photographing unit capable of photographing a stitch coupled to a knitting needle for knitting a knitted fabric;
a judging unit which compares the state of the stitch photographed by the photographing unit with the state of the stitch when it is normal based on the knitting data , and judges the quality of the stitch;
A position storage unit for storing the position of the stitch photographed by the photographing unit
A defect detection system provided.