U.S. patent application number 15/663830 was filed with the patent office on 2019-01-03 for image inspection device and method.
The applicant listed for this patent is NOPORVIS CO., LTD.. Invention is credited to Chun-Neng Chan, Kuo-Kai Hung, Pin-Cheng Kung.
Application Number | 20190005634 15/663830 |
Document ID | / |
Family ID | 63640326 |
Filed Date | 2019-01-03 |
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United States Patent
Application |
20190005634 |
Kind Code |
A1 |
Kung; Pin-Cheng ; et
al. |
January 3, 2019 |
IMAGE INSPECTION DEVICE AND METHOD
Abstract
An image inspection device includes a rotating platform
configured to carry a workpiece; a first image capturing device
configured to capture a top-view image of the workpiece; a second
image capturing device configured to capture a lateral-view image
of the workpiece; a storage unit configured to pre-store a
plurality of lateral-view images of a standard workpiece from
different angles; and a processing unit. The processing unit
controls the rotating platform to rotate the workpiece to a first
angle and a second angle according to the top-view image. The
processing unit is configured to generate a first comparison result
and a second comparison result by comparing the lateral-view images
of the workpiece with lateral-view images of the standard workpiece
from, respectively, the first angle and the second angle, and
determine whether the workpiece has a defect according to the first
comparison result and the second comparison result.
Inventors: |
Kung; Pin-Cheng; (Kaohsiung
City, TW) ; Hung; Kuo-Kai; (Tainan City, TW) ;
Chan; Chun-Neng; (Kaohsiung City, TW) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
NOPORVIS CO., LTD. |
KAOHSIUNG CITY |
|
TW |
|
|
Family ID: |
63640326 |
Appl. No.: |
15/663830 |
Filed: |
July 31, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G06T 2207/30164
20130101; G06T 7/001 20130101; G06T 2207/10016 20130101; H04N 5/247
20130101 |
International
Class: |
G06T 7/00 20060101
G06T007/00; H04N 5/247 20060101 H04N005/247 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 29, 2017 |
TW |
106121734 |
Claims
1. An image inspection device, comprising: a rotating platform
configured to carry a workpiece; a first image capturing device
configured to capture a top-view image of the workpiece; a second
image capturing device configured to capture a lateral-view image
of the workpiece; a storage unit configured to pre-store a
plurality of lateral-view images of a standard workpiece from
different angles; and a processing unit electrically connected to
the rotating platform, the first image capturing device, the second
image capturing device and the storage unit; wherein the processing
unit is configured to control the rotating platform to rotate the
workpiece to a first angle and to a second angle according to the
top-view image of the workpiece, such that the second image
capturing device is able to capture two lateral-view images of a
predetermined portion of the workpiece from, respectively, the
first angle and the second angle; wherein the processing unit is
further configured to generate a first comparison result by
comparing the lateral-view images of the predetermined portion of
the workpiece from the first angle with the lateral-view images of
the predetermined portion of the standard workpiece from the first
angle, and generate a second comparison result by comparing the
lateral-view images of the predetermined portion of the workpiece
from the second angle with the lateral-view images of the
predetermined portion of the standard workpiece from the second
angle; wherein the processing unit is further configured to
determine whether the workpiece has a defect according to the first
comparison result and the second comparison result.
2. The image inspection device of claim 1, wherein an angle between
an optical axis of the first image capturing device and the
horizontal plane is 90 degrees and an angle between an optical axis
of the second image capturing device and the horizontal plane is 30
degrees.
3. The image inspection device of claim 1, wherein the processing
unit is further configured to generate a first threshold value
according to a plurality of image similarities of the lateral-view
images of the predetermined portion of a plurality of predetermined
workpieces from the first angle and the lateral-view image of the
predetermined portion of the standard workpiece from the first
angle, and to generate a second threshold value according to a
plurality of image similarities of the lateral-view images of the
predetermined portion of a plurality of predetermined workpieces
from the second angle and the lateral-view image of the
predetermined portion of the standard workpiece from the second
angle.
4. The image inspection device of claim 3, wherein the first
threshold value is a multiple value of a standard deviation value
of the plurality of the image similarities of the lateral-view
images of the predetermined portion of the plurality of
predetermined workpieces from the first angle and the lateral-view
image of the predetermined portion of the standard workpiece from
the first angle, and the second threshold value is a multiple value
of a standard deviation value of the plurality of the image
similarities of the lateral-view images of the predetermined
portion of the plurality of predetermined workpieces from the
second angle and the lateral-view image of the predetermined
portion of the standard workpiece from the second angle.
5. The image inspection device of claim 3, wherein the processing
unit is further configured to determine whether the workpiece has a
defect by comparing the first comparison result with the first
threshold value and comparing the second comparison result with the
second threshold value.
6. The image inspection device of claim 1, wherein the storage unit
is further configured to pre-store a top-view image of a standard
workpiece, and the processing unit is further configured to
generate a third comparison result by comparing the top-view images
of the workpiece with the top-view images of the standard
workpiece, and determines whether the workpiece has a defect
according to the first comparison result, the second comparison
result and the third comparison result.
7. An image inspection method, comprising: storing a plurality of
lateral-view images of a standard workpiece taken from different
angles; placing a workpiece on a rotating platform; capturing a
top-view image of the workpiece; controlling the rotating platform
to rotate the workpiece to a first angle and to a second angle
according to the top-view image of the workpiece, such that a
second image capturing device is able to capture two lateral-view
images of a predetermined portion of the workpiece from,
respectively, the first angle and the second angle; generating a
first comparison result by comparing the lateral-view images of the
predetermined portion of the workpiece from the first angle with
the lateral-view images of the predetermined portion of the
standard workpiece from the first angle; generating a second
comparison result by comparing the lateral-view images of the
predetermined portion of the workpiece from the second angle with
the lateral-view images of the predetermined portion of the
standard workpiece from the second angle; and determining whether
the workpiece has a defect according to the first comparison result
and the second comparison result.
8. The image inspection method of claim 7, wherein an angle between
an optical axis of the first image capturing device and the
horizontal plane is 90 degrees and an angle between an optical axis
of the second image capturing device and the horizontal plane is 30
degrees.
9. The image inspection method of claim 7, further comprising:
generating a first threshold value according to a plurality of
image similarities of the lateral-view images of the predetermined
portion of a plurality of predetermined workpieces from the first
angle and the lateral-view image of the predetermined portion of
the standard workpiece from the first angle; generating a second
threshold value according to a plurality of image similarities of
the lateral-view images of the predetermined portion of a plurality
of predetermined workpieces from the second angle and the
lateral-view image of the predetermined portion of the standard
workpiece from the second angle.
10. The image inspection method of claim 9, wherein the first
threshold value is a multiple value of a standard deviation value
of the plurality of the image similarities of the lateral-view
images of the predetermined portion of the plurality of
predetermined workpieces from the first angle and the lateral-view
image of the predetermined portion of the standard workpiece from
the first angle, and the second threshold value is a multiple value
of a standard deviation value of the plurality of the image
similarities of the lateral-view images of the predetermined
portion of the plurality of predetermined workpieces from the
second angle and the lateral-view image of the predetermined
portion of the standard workpiece from the second angle.
11. The image inspection method of claim 9, wherein the processing
unit determines whether the workpiece has a defect by comparing the
first comparison result with the first threshold value and
comparing the second comparison result with the second threshold
value.
12. The image inspection method of claim 7, comprising: storing
top-view images of a standard workpiece; generating a third
comparison result by comparing the top-view images of the workpiece
with the top-view images of the standard workpiece; and determining
whether the workpiece has a defect according to the first
comparison result, the second comparison result and the third
comparison result.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
[0001] The present invention relates to an image inspection device
and method, and more particularly, to an image inspection device
and method for inspecting a workpiece having complex contours.
2. Description of the Prior Art
[0002] An inspection method of a blade wheel of a turbocharger
manually observes whether the blade wheel has any defects. Since a
standard blade wheel has multiple blades with complex contours, it
is difficult to observe all possible defects of the blade wheel
from one angle. Manually observing the blade wheel from different
angles, however, takes a lot of time and is both inefficient and
unreliable. In short, the manual inspection method is not able to
inspect a blade wheel quickly and efficiently.
SUMMARY OF THE INVENTION
[0003] The present invention provides an image inspection device
and method in order to solve the problems of the prior art.
[0004] According to an embodiment of the present invention, an
image inspection device comprises a rotating platform, a first
image capturing device, a second image capturing device, a storage
unit and a processing unit. The rotating platform is configured to
carry a workpiece. The first image capturing device is configured
to capture a top-view image of the workpiece. The second image
capturing device is configured to capture a lateral-view image of
the workpiece. The storage unit is configured to pre-store a
plurality of lateral-view images of a standard workpiece taken from
different angles. The processing unit is electrically connected to
the rotating platform, the first image capturing device, the second
image capturing device and the storage unit. The processing unit is
configured to control the rotating platform to rotate the workpiece
by a first angle and by a second angle according to the top-view
image of the workpiece, such that the second image capturing device
is able to capture two lateral-view images of a predetermined
portion of the workpiece at the first angle and at the second
angle, respectively. The processing unit is further configured to
generate a first comparison result by comparing the lateral-view
images of the predetermined portion of the workpiece at the first
angle with the lateral-view images of the predetermined portion of
the standard workpiece at the first angle, and generates a second
comparison result by comparing the lateral-view images of the
predetermined portion of the workpiece at the second angle with the
lateral-view images of the predetermined portion of the standard
workpiece at the second angle. The processing unit is further
configured to determine whether the workpiece has a defect
according to the first comparison result and the second comparison
result.
[0005] According to another embodiment of the present invention, an
image inspection method comprises: storing a plurality of
lateral-view images of a standard workpiece taken from different
angles; placing a workpiece on a rotating platform; capturing a
top-view image of the workpiece; controlling the rotating platform
to rotate the workpiece to a first angle and to a second angle
according to the top-view image of the workpiece, such that a
second image capturing device is able to capture two lateral-view
images of a predetermined portion of the workpiece at the first
angle and at the second angle, respectively; generating a first
comparison result by comparing the lateral-view images of the
predetermined portion of the workpiece at the first angle with the
lateral-view images of the predetermined portion of the standard
workpiece at the first angle; generating a second comparison result
by comparing the lateral-view images of the predetermined portion
of the workpiece at the second angle with the lateral-view images
of the predetermined portion of the standard workpiece at the
second angle; and determining whether the workpiece has a defect
according to the first comparison result and the second comparison
result.
[0006] In contrast to the prior art, the image inspection device
and method of the present invention are capable of rotating the
workpiece to a specific angle according to the top-view image of
the workpiece, and capable of comparing lateral-view images of the
workpiece from different angles with a lateral-view image of the
standard workpiece. As a result, the image inspection device and
method of the present invention are capable of inspecting a
workpiece having complex contours both quickly and efficiently.
[0007] These and other objectives of the present invention will no
doubt become obvious to those of ordinary skill in the art after
reading the following detailed description of the preferred
embodiment that is illustrated in the various figures and
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a diagram showing an image inspection device of
the present invention.
[0009] FIG. 2 is a top-view image of a standard workpiece captured
by the image inspection device of the present invention.
[0010] FIG. 3 is a lateral-view image of the standard workpiece
captured by the image inspection device of the present
invention.
[0011] FIG. 4 is a top-view image of a workpiece with defects
captured by the image inspection device of the present
invention.
[0012] FIG. 5 is a lateral-view image of the workpiece with defects
at a first angle captured by the image inspection device of the
present invention.
[0013] FIG. 6 is a top-view image of a workpiece with defects
captured by the image inspection device of the present
invention.
[0014] FIG. 7 is a lateral-view image of the workpiece with defects
at a second angle captured by the image inspection device of the
present invention.
[0015] FIG. 8 is a flowchart showing the image inspection method of
the present invention.
DETAILED DESCRIPTION
[0016] Please refer to FIG. 1, which is a diagram showing an image
inspection device 100 of the present invention. The image
inspection device 100 comprises a rotating platform 110, a first
image capturing device 120, a second image capturing device 130, a
storage unit 140 and a processing unit 150. The rotating platform
110 is configured to carry and rotate a work piece 300. The first
image capturing device 120 is arranged above the work piece 300 and
configured to capture a top-view image of the work piece 300. The
second image capturing device 130 is arranged on a lateral side of
the work piece 300 and configured to capture a lateral-view image
of the work piece 300. In the present embodiment, an angle between
an optical axis of the first image capturing device 120 and the
horizontal plane is 90 degrees, and an angle between an optical
axis of the second image capturing device 130 and the horizontal
plane is 30 degrees, but the present invention is not limited
thereto. The processing unit 150 is electrically connected to the
rotating platform 110, the first image capturing device 120, the
second image capturing device 130 and the storage unit 140. The
processing unit 150 is configured to control the rotating platform
110 to rotate the work piece 300, such that the second image
capturing device 130 is able to capture lateral-view images of a
predetermined portion of the workpiece 300 at different angles.
[0017] Refer to FIG. 2 and FIG. 3 in conjunction with FIG. 1. FIG.
2 is a top-view image of a standard workpiece captured by the image
inspection device of the present invention. FIG. 3 is a
lateral-view image of the standard workpiece captured by the image
inspection device of the present invention. In the present
embodiment, the standard workpiece is a blade wheel 310, comprising
six large blades 311 and six small blades 312. The processing unit
150 is configured to position the blade wheel 310 according to the
top-view image of the blade wheel 310 captured by the first image
capturing device 120. The blade wheel 310 may be located on the
rotating platform 110 at any angle. The processing unit 150 is
configured to determine characteristics of the blades (such as the
ridgeline 313 of the large blade 311) according to the top-view
image of the blade wheel 310, in order to control the rotating
platform 110 to rotate the blade wheel 310 to different angles
(such as angles A to F). The angles A to F are the angles of the
ridgeline 313 of the large blade 311 relative to the second image
capturing device 130. In the present embodiment, since the blade
wheel 310 comprises six large blades 311, the rotating platform 110
rotates the blade wheel 310 to six angles (from angle A to angle
F), wherein the difference between one of the angles A to F and the
next angle is 60 degrees, but the present invention is not limited
thereto. As shown in FIG. 3, the lateral-view image of the blade
wheel 310 captured by the second image capturing device 130 only
shows some blades, and only shows portions of the blades. For
example, FIG. 3 only shows a left portion of the large blade 311
(the marked large blade). Therefore, the image inspection device
100 of the present invention is able to rotate the blade wheel 310
by the rotating platform 110, in order to allow the second image
capturing device 130 to capture lateral-view images of the large
blade 311 of the blade wheel 310 from different angles. The storage
unit 140 is able to store the lateral-view images of the standard
workpiece at different angles. The processing unit 150 is
configured to determine whether the workpiece has a defect
according to a comparison of the lateral-view images of the
workpiece and the lateral-view images of the standard workpiece
from different angles.
[0018] Please refer to FIG. 4 to FIG. 7. FIG. 4 and FIG. 6 are
top-view images of a workpiece with defects captured by the image
inspection device of the present invention. FIG. 5 and FIG. 7 are
lateral-view images of the workpiece with defects captured by the
image inspection device from, respectively, a first angle and a
second angle. In the present embodiment, the workpiece under
inspection is a blade wheel 320, and a defect G and a defect H are
formed on a large blade 321 (the marked large blade). As shown in
FIG. 4, the image inspection device 100 of the present invention is
configured to position the blade wheel 320 according to the
top-view image of the blade wheel 320 captured by the first image
capturing device 120. The processing unit 150 is configured to
determine the characteristics of the blades of the blade wheel 320
according to the top-view image of the blade wheel 320, in order to
control the rotating platform 110 to rotate the large blade 321 of
the blade wheel 320 to angle A. As shown in FIG. 5, the second
image capturing device 130 captures a lateral-view image of the
blade wheel 320 from the angle A. The processing unit 150 is
further configured to generate a first comparison result by
comparing the lateral-view image of the blade wheel 320 with the
lateral-view image of the standard workpiece at angle A. The first
comparison result is a value of image similarity percentage. If the
image similarity of the lateral-view image of the blade wheel 320
at angle A and the lateral-view image of the standard workpiece at
angle A is high, the value of the first comparison is high. The
processing unit 150 is further configured to determine whether the
blade wheel 320 has a defect by comparing the first comparison
result with a first threshold value. The first threshold value is a
predetermined value and configured to determine whether the
workpiece (such as the blade wheel 320) has a defect.
[0019] In FIG. 5, the defect G and the defect H of the large blade
321 are only partially shown in the lateral-view image of the blade
wheel 320 at the angle A. As shown in FIG. 6, after the second
image capturing device 130 captures the lateral-view image of the
blade wheel 320 at angle A, the processing unit 150 is configured
to control the rotating platform 110 to rotate the large blade 321
(the marked large blade) of the blade wheel 320 to an angle B
according to the top-view image of the blade wheel 320. As shown in
FIG. 7, the second image capturing device 130 captures a
lateral-view image of the blade wheel 320 from the angle B. The
lateral-view image of the blade wheel 320 from the angle B is able
to show the portions not shown in the lateral-view image from the
angle A. Similarly, the processing unit 150 is configured to
generate a second comparison result by comparing the lateral-view
image of the blade wheel 320 with the lateral-view image of the
standard workpiece at angle B, and the processing unit 150 is
further configured to determine whether the blade wheel 320 has a
defect by comparing the second comparison result with a second
threshold value. In the present embodiment, when the first
comparison result is smaller than the first threshold vale and the
second comparison result is smaller than the second threshold vale,
the processing unit 150 determines the blade wheel 320 has a
defect, but the present invention is not limited thereto.
[0020] In addition, the image inspection device 100 of the present
invention is able to compare a small blade 322 of the blade wheel
320 with the standard workpiece at different angles to determine
whether the small blade 322 of the blade wheel 320 has a defect
when comparing the large blade 321 of the blade wheel 320 with the
standard workpiece. The inspected portion can be arranged according
to different requirements. Moreover, after the processing unit 150
determines whether the large blade 321 (the marked large blade) of
the blade wheel 320 has a defect, the processing unit 150 controls
the rotating platform 110 to further rotate the blade wheel 320, in
order to allow the second image capturing device 130 to capture
lateral-view images of other large blades 321 and other small
blades 322 of the blade wheel 320 from different angles. The
processing unit 150 is thereby able to further compare the
lateral-view images of other large blades 321 and other small
blades 322 of the blade wheel 320 with lateral-view images of the
standard workpiece. According to the above arrangement, the image
inspection device 100 of the present invention is capable of
inspecting a workpiece from different angles to determine whether
the workpiece has a defect, and solve the prior art problem of lack
of inspection accuracy.
[0021] Please refer to FIG. 1 again. In another embodiment of the
present invention, the storage unit 140 is further configured to
pre-store a top-view image of the standard workpiece. The
processing unit 150 is further configured to generate a third
comparison result by comparing the top-view image of the workpiece
300 with the top-view image of the standard workpiece, and
determine whether the workpiece 300 has a defect according to the
first comparison result, the second comparison result and the third
comparison result. The top-view image of the workpiece 300 captured
by the first image capturing device 120 is not only utilized as
positioning means by the processing unit 150, but also for
comparison with the top-view of the standard workpiece, such that
the workpiece 300 can be inspected by images captured at more
angles.
[0022] In the present invention, the above first threshold vale and
second threshold value can be generated according to statistical
values of a plurality of image similarities of the lateral-view
images of the predetermined portion of a plurality of predetermined
workpieces and the lateral-view image of the predetermined portion
of the standard workpiece. For example, the processing unit 150 is
configured to generate the first threshold value according to a
standard deviation value of the plurality of image similarities of
the lateral-view images of the predetermined portion of the
plurality of predetermined workpieces from the first angle and the
lateral-view image of the predetermined portion of the standard
workpiece from the first angle, and generates the second threshold
value according to a standard deviation value of the plurality of
the image similarities of the lateral-view images of the
predetermined portion of the plurality of predetermined workpieces
from the second angle and the lateral-view image of the
predetermined portion of the standard workpiece from the second
angle. The processing unit 150 is further configured to compare the
first comparison result with the first threshold value and compare
the second comparison result with the second threshold value, in
order to determine whether the workpiece has a defect. In the
present embodiment, the first threshold value and the second
threshold value are twice the standard deviation values, but the
present invention is not limited thereto. The multiple values of
the standard deviation value can be arranged according to different
requirements. When the top-view image is further configured to be
compared to generate a third comparison result, the processing unit
150 is further configured to generate the third threshold value
according to a standard deviation value of the plurality of the
image similarities of the top-view images of the plurality of
predetermined workpieces and the top-view image of the standard
workpiece, and compares the third comparison result with the third
threshold value to determine whether the workpiece has a
defect.
[0023] Please refer to FIG. 8, which is a flowchart 800 showing the
image inspection method of the present invention. The flowchart 800
comprises the following steps:
[0024] Step 810: store a plurality of lateral-view images of a
standard workpiece taken from different angles;
[0025] Step 820: place a workpiece on a rotating platform;
[0026] Step 830: capture a top-view image of the workpiece;
[0027] Step 840: control the rotating platform to rotate the
workpiece to a first angle and to a second angle according to the
top-view image of the workpiece, such that a second image capturing
device is able to capture two lateral-view images of a
predetermined portion of the workpiece from, respectively, the
first angle and the second angle;
[0028] Step 850: generate a first comparison result by comparing
the lateral-view images of the predetermined portion of the
workpiece from the first angle with the lateral-view images of the
predetermined portion of the standard workpiece from the first
angle;
[0029] Step 860: generate a second comparison result by comparing
the lateral-view images of the predetermined portion of the
workpiece from the second angle with the lateral-view images of the
predetermined portion of the standard workpiece from the second
angle; and
[0030] Step 870: determine whether the workpiece has a defect
according to the first comparison result and the second comparison
result.
[0031] The image inspection method of the present invention is not
limited to the above steps--other steps can be added to the image
inspection method, and the sequence of the steps is not limited to
the above.
[0032] In contrast to the prior art, the image inspection device
and method of the present invention are capable of rotating the
workpiece to a specific angle according to the top-view image of
the workpiece, and capable of comparing lateral-view images of the
workpiece from different angles with a lateral-view image of the
standard workpiece. As a result, the image inspection device and
method of the present invention are capable of inspecting a
workpiece having complex contours both quickly and efficiently.
[0033] Those skilled in the art will readily observe that numerous
modifications and alterations of the device and method may be made
while retaining the teachings of the invention. Accordingly, the
above disclosure should be construed as limited only by the metes
and bounds of the appended claims.
* * * * *