FIELD OF THE INVENTION
[0001] The invention relates to a circular knitting machine for determining a knitting machine
status, and more particularly to a circular knitting machine for prompting a knitting
machine status instantaneously based on a cloth surface status of a fabric.
BACKGROUND OF THE INVENTION
[0002] The knitting quality of a circular knitting machine depends on whether there are
defects in the fabric surface status, and the occurrence of defects is closely related
to the stitch status of a plurality of knitting needles on the circular knitting machine.
When the lower edge of the stitch of one of the knitting needles wears too much, the
push-up height of one of the knitting needles will be incapable of reaching the expected
height, resulting in the following situations: the tongue cannot be fully opened;
the old yarn ring has not been cleared (knitting needle knits with double yarns erroneously),
the crochet hook cannot hook the new yarn (holes appear in the fabric). On the other
hand, when the upper edge of the stitch of one of the knitting needles wears too much,
it will cause the following situations: the old yarn ring can not be reliably released
(in addition to the holes in the fabric, abnormal line textures can be found visually
on the fabric after knitting); the knitted yarn loop is smaller than the yarn loop
knitted in the previous period (abnormal line textures can be found visually on the
fabric).
[0003] Although there are many technical solutions for testing the quality of fabrics, such
as disclosed in
CN102778414A,
CN102967606A,
CN103451846A,
CN103604809A,
CN108364291A,
CN108921819A,
CN109696442A,
CN110389130A, a point in time for the aforementioned techniques to perform quality testing on
knitting is after the knitting machine has finished knitting, even if the fabric is
found to be defective, it is impossible to determine which part of the knitting needles
of the circular knitting machine needs to be replaced. As a result, the common practice
of manufacturers is to replace all the knitting needles on the circular knitting machine
after learning that the fabric is defective, since a quantity of knitting needles
on the circular knitting machine is generally 1500-2640, the quantity of knitting
needles being replaced at one time is too high, and condition assessment for all the
knitting needles does not meet the time cost. This will cause waste of resources and
increase the production costs of manufacturers in a disguised form.
[0004] In addition to the foregoing, although there are also technical solutions for testing
the quality of fabrics on the circular knitting machine, such as disclosed in
CN105044121A,
CN110188806A, and
CN111812108A, the aforementioned techniques still focus only on the testing of fabric quality
and do not correlate the testing results with the conditions of the knitting machine,
resulting in manufacturers still having to replace all the knitting needles to solve
the problem of abnormal knitting quality. Furthermore, all the technical solutions
disclosed in the aforementioned patents require the computer that mainly performs
identification to perform feature learning on the conditions of the fabric before
making judgments. In practice, the circular knitting machine is not designed to be
capable of knitting into a single fabric type only, if feature learning is performed
at the beginning of production of a fabric type, it is very likely that feature learning
will not be completed at the end of the entire fabric production, which obviously
does not meet the actual requirements. Furthermore, if it is planned to complete feature
learning before production of a fabric, it means that the circular knitting machine
needs to knit a large amount of fabrics for the computer to perform feature learning
before actual production. For manufacturers, with a large amount of knitted fabrics
that need to be regarded as discarded products, the production costs are bound to
increase substantially, which does not meet the actual requirements.
[0005] Although knitting factories inspect the knitting machine manually, the aforementioned
knitting defects cannot be discovered through simple inspections, and the knitting
factories will have the problem that knitting defects have already occurred but the
knitting machine continues to knit the defective fabrics. The knitting factories have
to wait until doffing is over and the fabrics have transported in rolls to the quality
inspection department for fabrics inspection before knitting defects can be found.
At this time, the knitting factories can only treat the fabrics with weaving defects
as discarded products, resulting in a waste of resources.
SUMMARY OF THE INVENTION
[0006] A main object of the invention is to solve the problem that the conventional circular
knitting machine is incapable of knowing specific positions to be repaired from detection
results of a cloth surface status of a fabric.
[0007] A secondary object of the invention is to solve the problem derived from the conventional
circular knitting machine being incapable of defecting defects synchronously during
doffing.
[0008] In order to achieve the above objects, the invention provides a circular knitting
machine for prompting a knitting machine status instantaneously based on a cloth surface
status of a fabric. The circular knitting machine comprises a cam supporting base
and a needle cylinder driven to rotate relative to the cam supporting base, and the
circular knitting machine is started to knit the fabric which is doffed a side of
the needle cylinder opposite to the cam supporting base. The circular knitting machine
comprises a camera module, an information processing unit, and an encoder. The camera
module photographs the fabric during doffing and generating a plurality of image data,
wherein a camera lens of the camera module is not rotated with the needle cylinder,
and is controlled by a plurality of photographing signals to photograph the fabric
during doffing. The information processing unit receives the plurality of image data
and comparing each image data with another image data which is located on a same vertical
line of the fabric and photographed in at least one previous revolution of the needle
cylinder, wherein a knitting machine status is prompted when a difference occurs.
The encoder generates a plurality of pulse signals when the needle cylinder rotating,
and the encoder outputs the plurality of pulse signals to one of the camera module
and the information processing unit to count the plurality of pulse signals and to
generate the plurality of photographing signals, wherein a count value used by the
one of the camera module and the information processing unit is a factor of a total
amount of the plurality of pulse signals during the needle cylinder rotating one revolution.
[0009] In one embodiment, a number of photographing times of the camera module divides a
central angle equally and divides a total amount of a plurality of knitting needles
belonging to the needle cylinder with no remainder.
[0010] In one embodiment, an amount of horizontal loop images included in each of the image
data is the same, and each horizontal loop images corresponds to one of the plurality
of knitting needles on the circular knitting machine.
[0011] In one embodiment, an amount of longitudinal loop images included in each of the
image data is the same, and a total length of the longitudinal loop images is proportional
to an amount of doffing in one revolution of the needle cylinder.
[0012] In one embodiment, the circular knitting machine comprises a mounting arm provided
for the camera lens being suspended within an area surrounded by the needle cylinder.
[0013] In one embodiment, the mounting arm is offset from a center of the area surrounded
by the needle cylinder.
[0014] In one embodiment, the information processing unit compares chromogenic pixels between
the plurality image data.
[0015] Accordingly, comparing with the conventional techniques, the invention has the following
features. After the camera module of the invention is installed, the camera lens belonging
to the camera module does not rotate with the needle cylinder, trigger of shooting
of the camera lens is based on the shooting signals generated by counting the pulse
signals with the camera module or the information processing unit, and the image data
are generated by photographing the fabric during doffing with the camera lens. The
information processing unit does not need to perform deep learning required to determine
the defects of the fabric in advance, but compares each of the image data with another
one of the image data that is located on a same vertical line and photographed in
at least one previous revolution of the needle cylinder, which greatly reduces a computational
capability required for the information processing unit, which means that the hardware
requirements are reduced. However, although the invention reduces a capability required
for computing, it does not reduce a determining efficiency. Compared with the prior
art, the invention is capable of determining defects generated on the fabric more
quickly, so that an operator can immediately eliminate a cause. In addition, the invention
is capable of prompting the operator which part of the circular knitting machine has
a problem and should be replaced only based on one of the abnormal image data, and
specifically solving the problem of waste of resources caused by the existing technical
skills being incapable of checking a status of the knitting needles belonging to the
circular knitting machine one by one, and only capable of replacing all the knitting
needles. In addition, the invention is capable of finding defects on the fabric immediately,
so that the operator can stop the circular knitting machine, immediately prevent continuous
production of the defective fabric, and resume production after a cause of defects
is eliminated, thereby avoiding the problem of excessive discarded products caused
by judging defects after the fabric is completed in the current implementation process
of the prior art.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016]
FIG. 1 is a perspective view of partial structures of a circular knitting machine
according to an embodiment of the invention;
FIG. 2 is a cross-sectional view of partial structures of the circular knitting machine
according to an embodiment of the invention;
FIG. 3 is a block diagram of implementation units of the circular knitting machine
according to an embodiment of the invention;
FIG. 4 is a block diagram of implementation units of the circular knitting machine
according to another embodiment of the invention;
FIG. 5 is a schematic diagram of a fabric according to an embodiment of the invention;
and
FIG. 6 is a schematic diagram of image data containing fabric defects according to
an embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0017] The detailed description and technical contents of the invention are described below
with reference to the drawings.
[0018] Please refer to FIG. 1, FIG. 2, FIG. 3, and FIG. 4. The invention provides a circular
knitting machine 20which is capable of prompting a knitting machine status instantaneously
based on a cloth surface status produced during knitting a fabric 30. Herein, implementation
of the circular knitting machine 20 is explained below. The circular knitting machine
20 comprises a cam supporting base 21, an encoder 22, and a needle cylinder 23. The
basic configurations of the cam supporting base 21 and the needle cylinder 23 are
circular, and the needle cylinder 23 is disposed on an inner ring of the cam supporting
base 21. The needle cylinder 23 is driven by a driving member (not shown in the figures)
to rotate relative to the cam supporting base 21, and a plurality of knitting needles
231 on the needle cylinder 23 are guided to perform a knitting action by a plurality
of cam sets 211 of the cam supporting base 21 when the needle cylinder 23 rotates.
In addition, when the circular knitting machine 20 is started, the fabric 30 is knitted
and doffed from a side of the needle cylinder 23 opposite to the cam supporting base
21. The encoder 22 generates a plurality of pulse signals 221 when the needle cylinder
23 rotates, wherein the plurality of pulse signals 221 are generated regularly and
continuously, and the plurality of pulse signals 221 generated by the encoder 22 are
constant when the needle cylinder 23 rotates one revolution. In the technical field
of the circular knitting machine 20, the plurality of pulse signals 221 are only used
to determine a rotation angle of the needle cylinder 23.
[0019] The circular knitting machine 20 of the invention further comprises a camera module
24 and an information processing unit 25. The camera module 24 photographs the fabric
30 during doffing and generates a plurality of image data 241. More specifically,
a camera lens 242 of the camera module 24 is disposed at a position that can photograph
the fabric 30 during doffing. In one embodiment, the circular knitting machine 20
comprises a mounting arm 26 provided for the camera lens 242 being suspended within
an area surrounded by the needle cylinder 23, wherein the mounting arm 26 can be disposed
on a yarn feeding ring (not shown in the figures) of the circular knitting machine
20, or installed on an external structure not belonging to the circular knitting machine
20. Considering shooting distance and photographing quality of the camera lens 242,
the mounting arm 26 is not limited to being located at a center of the area surrounded
by the needle cylinder 23, but can be offset from a center. In the invention, the
camera lens 242 is not rotated with the needle cylinder 23, that is to say, the camera
lens 242 is fixed at one place to photograph objects passing by the camera lens 242.
The camera lens 242 does not continuously photograph the fabric 30, and therefore
does not produce film data. The camera lens 242 only photographs the fabric 30 during
doffing when receiving a plurality of photographing signals 27.
[0020] Please refer to FIG. 3 and FIG. 4, the explanation of the plurality of photographing
signals 27 is described as follow. Firstly, in one embodiment, the camera module 24
is provided with an operating unit 243 which calculates received information based
on a memorized operating program. Besides, the information processing unit 25 is implemented
as a central control module of the circular knitting machine 20, and the information
processing unit 25 is connected to the camera module 24 in a wired or wireless manner
to receive the plurality of image data 241 generated by the camera module 24. Further,
the plurality of pulse signals 221 generated by the encoder 22 are not only used to
control the circular knitting machine 20 originally, but are also output to the camera
module 24 or the information processing unit 25, wherein it should be noticed that
the prerequisite for selecting to output the plurality of pulse signals 221 to the
camera module 24 is that the camera module 24 is provided with the operating unit
243. The camera module 24 or the information processing unit 25 is a receiver of the
plurality of pulse signals 221 to count the plurality of pulse signals 221 and generate
the plurality of photographing signals 27, wherein a count value used by the receiver
is a factor of a total amount of the plurality of pulse signals 221 during the needle
cylinder 23 rotating one revolution. For example, a total amount of the plurality
of pulse signals 221 generated by the encoder 22 during one revolution of the needle
cylinder 23 is "2640", so that the count value can be selected as a value which is
able to divide "2640" with no remainder, such as "88". In this way, the receiver (the
camera module 24 or the information processing unit 25) will generate one of the plurality
of photographing signals 27 whenever receiving eighty-eight pulse signals 221. Accordingly,
a number of photographing times of the camera module 24 is a quotient obtained by
dividing the total amount of the plurality of pulse signals 221 by the count value.
For instance, a number of photographing times is "30" in the previous example. However,
in order to make the time of photographing times of the camera module 24 the same
in each revolution of the needle cylinder 23, the number of photographing times needs
to be capable of dividing a central angle equally. Preferably, the number of photographing
times divides a total amount of the plurality of knitting needles 231 belonging to
the needle cylinder 23 with no remainder, so that the plurality image data 241 comprises
the knitting needles 231 equally. The information processing unit 25 prompts an operator
that which part of the plurality of knitting needles 231 is abnormal based on one
of the plurality of image data 241 where abnormality occurs. As described in the previous
example, a total amount of the knitting needles 231 is "2640", and a number of photographing
times of the camera module 24 is "30", which means that the camera module 24 will
take one photograph when the needle cylinder 23 rotates every twelve degrees, and
a total amount of the plurality of image data 241 generated by the needle cylinder
23 in one revolution is "30". In this way, each of the plurality of image data 241
comprises eighty-eight knitting needles 231, in other words, one of the plurality
of image data 241 comprises the 1st needle to the 88th needle of the knitting needles
231, the other one of the image data 241 successively generated comprises the 89th
needle to the 176th needle of the knitting needles 231. Further referring to FIG.
5, an amount of horizontal loop images 601 included in each of the plurality of image
data 241 is the same, and each of the horizontal loop images 601 corresponds to one
of the plurality of knitting needles 231 on the circular knitting machine 20. In addition,
an amount of longitudinal loop images 602 included in each of the plurality of the
image data 241 is the same, and a total length of the longitudinal loop images 602
is proportional to an amount of doffing in one revolution of the needle cylinder 23.
In this way, an object to be repaired can be quickly found based on one of the plurality
of image data 241 in which a difference is determined.
[0021] In addition, the information processing unit 25 performs image comparison on the
plurality of image data 241 based on a pre-memorized execution procedure, and the
information processing unit 25 compares each of the plurality of image data 241 (marked
as A in FIG. 5) with the other one of the plurality of image data 241 (marked as B
in FIG. 5) that is located on a same vertical line 50 and photographed by the camera
module 24 in a previous revolution of the needle cylinder 23. That is, if one of the
plurality of image data 241 to be compared is the 24th image data 241 captured by
the camera module 24 during a second revolution of the needle cylinder 23, the other
one of the plurality of image data 241 in comparison is the 24th image data 241 captured
by the camera module 24 during a first revolution of the needle cylinder 23, and the
two image data 241 are continuously formed on the vertical line 50, representing continuous
doffing of the fabric 30 during a knitting process. After the information processing
unit 25 compares the foregoing two image data 241, a knitting machine status is prompted
once a difference is found. Specifically, the comparison referred in the invention
means to compare chromogenic pixels of two of the plurality of image data 241 to be
compared. Please refer to FIG. 6 as an example that shows one embodiment that the
fabric 30 comprises defects. A loose loop area 603 can be directly observed from FIG.
6, and the rest of the fabric 30 is a normal loop area 604. Images of the loose loop
area 603 are different from images of the normal loop area 604, and all the image
data 241 are electronic data. Between the plurality of image data 241, the chromogenic
pixels corresponding to the same location of the fabric are different. For example,
the plurality of image data 241 define color rendering of each of the chromogenic
pixels with trichromatic light modes (RGB). Under normal conditions, RGB parameters
of the chromogenic pixels on a same part of the image data 241 are: R227, G23, B13.
When the RGB parameters of the chromogenic pixels on a same part of one of the image
data 241 are changed to R41, G36, B33, the information processing unit 25 determines
that there is a difference. It should be understood that the examples mentioned in
this specification are only illustrations. In practice, the information processing
unit 25 performs similar or identical comparisons with a wide range of image feature
values. The technical method of image comparison is not an emphasis of the application
of the invention, but can be implemented with any existing technique that can achieve
a same effect.
[0022] Furthermore, if the latest shooting information of the camera module 24 is shown
as FIG.6, the information processing unit 25 compares image data 241 of FIG.6 with
the other image data 241 (not shown in the figure) on the same vertical line 50 and
photographed in a previous revolution of the needle cylinder 23. In one embodiment,
assuming that the other image data 241 mentioned above is normal knitting, none of
the loose loop area 603 will be existed. The chromogenic pixels of the loose loop
area 603 in FIG. 6 are different from the chromogenic pixels of the normal loop area
604, and after the information processing unit 25 compares all parts of the two image
data 241, the information processing unit 25 determines that the fabric 30 has quality
defects if a difference (color rendering difference) between two of the image data
241 is greater than an allowable value, and a knitting machine status is prompted.
The prompt referred to herein can be achieved by a variety of technical solutions,
such as driving a prompt lamp or a prompt bell on the circular knitting machine 20
to generate an action, or the information processing unit 25 transmits a signal to
an information equipment 28 via a wired or wireless method, and the signal is read
by an operator. The information equipment 28 can be a terminal equipment held by the
operator, or a server that can be communicatively connected with the terminal equipment.
In addition to the foregoing, the information processing unit 25 can also be set to
immediately request the encoder 22 to stop sending a signal to drive the needle cylinder
23 when a cloth surface status of the fabric 30 is detected to be abnormal, so that
the circular knitting machine 20 is temporarily shut down to prevent the fabric 30
of poor quality from being continuously knitted.
1. A circular knitting machine (20) for prompting a knitting machine status instantaneously
based on a cloth surface status of a fabric (30), the circular knitting machine (20)
comprising a cam supporting base (21) and a needle cylinder (23) driven to rotate
relative to the cam supporting base (21), and the circular knitting machine (20) being
started to knit the fabric (30) which is doffed a side of the needle cylinder (23)
opposite to the cam supporting base (21), the circular knitting machine (20) comprising:
a camera module (24), photographing the fabric (30) during doffing and generating
a plurality of image data (241), wherein a camera lens (242) of the camera module
(24) is not rotated with the needle cylinder (23), and is controlled by a plurality
of photographing signals (27) to photograph the fabric (30) during doffing;
an information processing unit (25), receiving the plurality of image data (241) and
comparing each image data (241) with another image data (241) which is located on
a same vertical line (50) of the fabric (30) and photographed in at least one previous
revolution of the needle cylinder (23), wherein a knitting machine status is prompted
when a difference occurs; and
an encoder (22), generating a plurality of pulse signals (221) when the needle cylinder
(23) rotating, and the encoder (22) outputting the plurality of pulse signals (221)
to one of the camera module (24) and the information processing unit (25) to count
the plurality of pulse signals (221) and to generate the plurality of photographing
signals (27), wherein a count value used by the one of the camera module (221) and
the information processing unit (25) is a factor of a total amount of the plurality
of pulse signals (221) during the needle cylinder (23) rotating one revolution.
2. The circular knitting machine (20) for prompting a knitting machine status instantaneously
based on a cloth surface status of the fabric as claimed in claim 1, wherein a number
of photographing times of the camera module (24) divides a central angle equally and
divides a total amount of a plurality of knitting needles (231) belonging to the needle
cylinder (23) with no remainder.
3. The circular knitting machine (20) for prompting a knitting machine status instantaneously
based on a cloth surface status of the fabric as claimed in claim 1 or 2, wherein
an amount of horizontal loop images (601) included in each of the image data (241)
is the same, and each horizontal loop images (601) corresponds to one of the plurality
of knitting needles (231) on the circular knitting machine (20).
4. The circular knitting machine (20) for prompting a knitting machine status instantaneously
based on a cloth surface status of the fabric as claimed in claim 3, wherein an amount
of longitudinal loop images (602) included in each of the image data (241) is the
same, and a total length of the longitudinal loop images (602) is proportional to
an amount of doffing in one revolution of the needle cylinder (23).
5. The circular knitting machine (20) for prompting a knitting machine status instantaneously
based on a cloth surface status of the fabric as claimed in claim 4, wherein the circular
knitting machine (20) comprises a mounting arm (26) provided for the camera lens (23)
being suspended within an area surrounded by the needle cylinder (23).
6. The circular knitting machine (20) for prompting a knitting machine status instantaneously
based on a cloth surface status of the fabric as claimed in claim 5, wherein the mounting
arm (26) is offset from a center of the area surrounded by the needle cylinder (23).
7. The circular knitting machine (20) for prompting a knitting machine status instantaneously
based on a cloth surface status of the fabric as claimed in claim 1, wherein the circular
knitting machine (20) comprises a mounting arm (26) provided for the camera lens (242)
being suspended within an area surrounded by the needle cylinder (23).
8. The circular knitting machine (20) for prompting a knitting machine status instantaneously
based on a cloth surface status of the fabric as claimed in claim 7, wherein the mounting
arm (26) is offset from a center of the area surrounded by the needle cylinder (23).
9. The circular knitting machine (20) for prompting a knitting machine status instantaneously
based on a cloth surface status of the fabric as claimed in claim 7 or 8, wherein
the information processing unit (25) compares chromogenic pixels between the plurality
image data (241).