TWI855329B - Detection system - Google Patents

Abstract

The present disclosure provides a detection system including a first detection module, a sensing module, and a control module. The first detection module includes a first photographing device and a first light source. The first photographing device is used to capture an image of a product to be tested, and the first light source is an area light source, which is used to illuminate the product when the first photographing device captures the image of the product. The sensing module is used to generate a sensing signal when sensing the product. The control module connects the first photographing device, the first light source, and the sensing module, which is used to control the first light source emitting light and the first photographing device capturing the image when receiving the sensing signal. The control module is also used to analyze the image to determine whether the product is qualified.

Description

Detection system

This application involves the field of product testing technology, and in particular, a testing system.

The production of a complete product often requires multiple production processes. After each production process is completed, the product usually needs to be quality inspected to evaluate whether the product obtained by the previous production process is qualified. A detection device for detecting whether a product is qualified obtains information such as the shape and structure of the product by taking an image of the product, thereby evaluating whether the product is qualified. The detection device illuminates the product with an annular light source and takes an image of the product. Since the illumination range of the annular light source is small, different positions of the product are bright and dark when it is illuminated on the product. When the shooting angle changes, the distribution of light and dark in the captured image will also change. In the process of analyzing the image, the highlight part of the image is captured. Therefore, when the shooting angle changes, the highlight part captured subsequently will be offset. It can be seen that when using this kind of detection device using a ring light source to detect product quality, the shooting angle requirement is relatively high. That is, only images of products shot at a specific angle can be used to obtain information such as the shape and structure of the product. If the shooting angle is offset, the image taken will be unusable and the product information cannot be effectively obtained.

The present application embodiment provides a detection system, comprising: a first detection module, including a first camera and a first light source, the first camera is used to capture an image of a product to be detected, the first light source is a surface light source, used to emit light to illuminate the product to be detected when the first camera captures the image of the product to be detected; a sensing module, used to generate a sensing signal when sensing the product to be detected; and a control module, respectively connected to the first camera, the first light source and the sensing module, used to control the first light source to emit light and control the first camera to capture an image when receiving the sensing signal, and the control module is also used to analyze the image to determine whether the product to be detected is qualified.

The above detection system includes a first detection module, which includes a first camera and a first light source, wherein the first light source is a surface light source. During the shooting process of the first camera, since the first light source is a surface light source, the light emitted by the first light source can maintain uniform brightness in a large area where the product to be tested is located. Even if the shooting angle is offset (that is, the first camera is not shooting completely facing the product to be tested), a clear image of the product to be tested can be captured.

1: Detection system

10: First detection module

11: First shooting device

12: The first light source

121: Luminous board

1211: Substrate

1212: Light-emitting element

122: Reflector

1221: Reflective part

S: Reflective surface

1222:Connection part

1223, 221: through hole

1224: Hollow Space

13: Light baffle

20: Second detection module

21: Second camera device

22: Second light source

30:Sensor module

31: First sensor

32: Second sensor

40: Control module

50: Main frame

2: Transmission device

Figure 1 is a schematic diagram of the module structure of the detection system in the embodiment of this application.

Figure 2 is a schematic diagram of the structure of the detection system in the embodiment of this application.

Figure 3 is a schematic diagram of the three-dimensional structure of the first detection module in Figure 2.

Figure 4 is a schematic diagram of the disassembly of the first light source in Figure 3.

Figure 5 is a schematic diagram of the structure of the light-emitting panel in Figure 4.

Figure 6 is another structural schematic diagram of the detection system in the embodiment of this application.

Figure 7 is another schematic diagram of the structure of the detection system in the embodiment of this application.

Figure 8 is another structural schematic diagram of the detection system in the embodiment of this application.

Figure 9 shows an image of the product to be tested taken when the shooting device is facing the product to be tested in a comparative example.

Figure 10 shows an image of the product to be tested taken by the shooting device when the shooting angle is offset in a comparative example.

Figure 11 is an image of the product to be tested taken when the first shooting device in this embodiment is facing the product to be tested.

Figure 12 is an image of the product to be tested taken by the first shooting device in this embodiment when the shooting angle is offset.

The detection system provided in this application is used to detect whether the product to be tested is qualified. In this embodiment, the product to be tested is a plastic bottle with a label attached, and the detection system is used to detect whether the bottle mouth and label of the plastic bottle meet the requirements. In this embodiment, the detection system evaluates whether the bottle mouth and label meet the requirements by taking images of the bottle mouth and label of the plastic bottle respectively.

In order to mass produce products, a conveying device (such as a conveyor belt) is usually installed on the production line to sequentially convey multiple products to be tested from the first processing station to the second processing station. When the detection system of this embodiment is applied to the production line, it is fixed on the side of the conveying device. That is, during the operation of the production line, the conveying device continuously conveys the products to be tested, and the position of the detection system remains fixed, and the products to be tested passing through its position are detected sequentially.

Please refer to Figure 1. In this embodiment, the detection system 1 includes a first detection module 10, a second detection module 20, a sensing module 30 and a control module 40, wherein the control module 40 is connected and communicates with the first detection module 10, the second detection module 20 and the sensing module 30 respectively.

Please refer to FIG. 2 . In this embodiment, the detection system 1 further includes a main support 50 . The main support 50 is a rigid electrical insulating material, which is mainly used to support the first detection module 10 , the second detection module 20 , and the sensing module 30 , and to fix and maintain the relative positions of the first detection module 10 , the second detection module 20 , and the sensing module 30 .

Please refer to Figure 3. In this embodiment, the first detection module 10 includes a first camera 11 and a first light source 12. In this embodiment, the first camera 11 is an industrial camera, which is used to capture images of the part to be detected of the product to be detected (the bottle mouth in this embodiment). The first light source 12 is used to emit light when the first camera 11 is shooting, so as to enhance and even out the brightness of the shooting environment of the first camera 11. In this embodiment, when the bottle as the product to be tested is placed on the conveying device 2, its bottom directly contacts the conveying device 2. When the bottle passes through the first camera 11, the bottle mouth is away from the conveying device 2 and faces the first camera 11, so that the first camera 11 can shoot.

Please refer to FIG. 4. In this embodiment, the first light source 12 includes two light-emitting plates 121. Please refer to FIG. 5. Each light-emitting plate 121 includes a substrate 1211 and a plurality of light-emitting elements (such as light-emitting diodes) 1212 located on the same surface of the substrate 1211. The plurality of light-emitting elements 1212 are arranged in an array at intervals. Each light-emitting element 1212 emits light in the same direction, and the light brightness emitted by each light-emitting element 1212 is the same, so that each light-emitting plate 121 acts as a light source to emit a whole surface of uniform brightness.

The first light source 12 also includes a reflector 122. The reflector 122 includes two reflective portions 1221 and a connecting portion 1222 connected between the two reflective portions 1221. The two reflective portions 1221 and the connecting portion 1222 are integrally formed. Each reflective portion 1221 has a reflective surface S, and the reflective surface S is used to reflect the received light. In some embodiments, the reflective surface S of each reflective portion 1221 is also used to scatter the received light.

In this embodiment, each light-emitting plate 121 and each reflective portion 1221 are substantially rectangular sheet structures. The connecting portion 1222 is substantially a sheet structure with a through hole 1223, and is respectively connected to one edge of the two reflective portions 1221. The two light-emitting plates 121 are arranged in parallel with each other, and the surfaces of the two light-emitting plates 121 for emitting light are arranged opposite to each other. The two reflective portions 1221 are arranged in parallel with each other, and the reflection surfaces S of the two reflective portions 1221 are arranged opposite to each other. The two opposite edges of each light-emitting plate 121 are respectively connected to the two reflective portions 1221, and the two opposite edges of each reflective portion 1221 are respectively connected to the two light-emitting plates 121. That is, the two light-emitting plates 121 and the two reflective portions 1221 together form a cylindrical structure with a hollow space 1224.

In this way, when the two light-emitting plates 121 emit light, the light emitted by the light-emitting plates 121 is reflected multiple times by the two reflective parts 1221, and light with uniform brightness can be formed in the hollow space 1224 to illuminate the product to be tested. In this embodiment, the two light-emitting plates 121 are both surface light sources, which can form a shooting environment with uniform brightness in a larger space, which is conducive to improving the shooting quality.

In this embodiment, the reflection surface S of each reflective portion 1221 is perpendicular to the plane where the extension direction of the transmission device 2 is located, and the first camera 11 is located on one side of the connecting portion 1222 of the first light source 12, and is arranged opposite to the through hole 1223 of the connecting portion 1222. That is, the orthographic projection of the first camera 11 on the first light source 12 is located in the through hole 1223. In this way, the first camera 11 can capture the image of the product to be tested through the through hole 1223.

In this embodiment, the moving direction of the product to be tested on the conveying device 2 is the direction indicated by the dotted arrow in FIG. 2 or FIG. 8 , and the moving direction of the product to be tested is parallel to the two light-emitting plates 121 and perpendicular to the two reflective portions 1221. The product to be tested has a certain height, and in order to facilitate the passing of the product to be tested, the length of the side where the two reflective portions 1221 connect to the light-emitting plate 121 is shorter than the length of the side where the light-emitting plate 121 connects to the reflective portion 1221. That is, the two reflective portions 1221 are farther from the conveying device 2 than the two light-emitting plates 121. When the product to be tested is located directly below the first photographing device 11, the light emitted by the first light source 12 evenly illuminates the product to be tested, and the first photographing device 11 photographs the image of the bottle mouth of the product to be tested to obtain a clearer bottle mouth outline.

In this embodiment, the first detection module 10 further includes two light shielding plates 13. The two light shielding plates 13 are thin sheets formed of light-shielding materials. The two light shielding plates 13 are arranged in parallel and fixedly disposed on both sides of the conveying device 2. When the first light source 12 emits light, the two light shielding plates 13 are used to shield external light to prevent the product to be tested from being irradiated by external light. That is, in this embodiment, the two light shielding plates 13 make the area and brightness of the product to be tested to be determined by the first light source 12 as much as possible without being disturbed by external light. When the product to be tested is transmitted to the first camera 11, the product to be tested is located between the two light-blocking plates 13. The area between the two light-blocking plates 13 isolates the external light, so that the contrast between the bottle mouth of the product to be tested and other positions is increased, which is conducive to obtaining a clear outline of the bottle mouth. The above-mentioned external light is, for example, light emitted by other processing stations on the production line, or ambient light, or light from the second detection module 20 (when the first detection module 10 and the second detection module 20 are close to each other).

In other embodiments, the first light source 12 includes four light-emitting panels but no reflective panels, that is, the four light-emitting panels are connected in sequence to form a cylindrical structure with a hollow space. The cylindrical structure in this embodiment can be seen in Figure 2. In this embodiment, since all four sides are light-emitting panels, it is no longer necessary to obtain light with uniform brightness through multiple reflections. Compared with the embodiment shown in Figure 2, it is beneficial to improve the uniformity of light. However, the first light source 12 shown in Figure 2 includes fewer light-emitting panels, which is beneficial to control costs.

The second detection module 20 is used to capture the image of the label of the product to be tested. Please refer to Figure 6. In this embodiment, the second detection module 20 includes a second camera 21 and a second light source 22. In this embodiment, the second camera 21 is an industrial camera, which is used to capture the image of the label of the product to be tested. The product to be tested also has a bottle body connecting the bottle mouth and the bottle bottom, and the label is attached to the outer surface of the bottle body. When the product to be tested is placed on the conveying device 2, the label faces the second camera 21.

The second light source 22 is used to emit light when the second shooting device 21 shoots, so as to increase the brightness of the shooting environment of the second shooting device 21. The second light source 22 includes a plurality of light-emitting elements (not shown in the figure, such as light-emitting diodes), which are arranged in an array at intervals, each light-emitting element emits light in the same direction, and the brightness of the light emitted by each light-emitting element is the same, so that the second light source 22, as a light source, emits a whole surface of light with uniform brightness.

In this embodiment, the second light source 22 is in the shape of a flat plate, and is provided with a through hole 221. The second photographing device 21 is located on the light emitting side of the second light source 22, and is used to photograph the image of the product to be tested through the through hole 221.

In this embodiment, the second camera 21 and the first camera 11 are sequentially arranged along the extension direction of the conveying device 2 (i.e., the displacement direction of the conveyed product to be tested), so as to sequentially collect images of the label and the bottle mouth of the product to be tested. That is, during the conveying process, the product to be tested first passes through the second camera 21, and the second camera 21 obtains the image of the label, and then passes through the first camera 11, and the first camera 11 takes the image of the bottle mouth. In other embodiments, the position sequence of the first camera 11 and the second camera 21 may be different.

Please refer to Figure 7. Since the product to be tested may be attached with multiple labels, for example, when the product to be tested has a front label and a back label attached. In this embodiment, the detection system 1 includes two second detection modules 20, and the two second detection modules 20 are symmetrically arranged on both sides of the conveying device 2 to respectively obtain images of different labels on the product to be tested. In other embodiments, the detection system 1 may include only one second detection module 20.

Please refer to Figure 8. In this embodiment, the sensing module 30 includes a first sensor 31 and a second sensor 32. The first sensor 31 and the second sensor 32 may be infrared sensors, which are used to sense whether a product to be tested passes by at their location. The first sensor 31 and the second sensor 32 are used to emit infrared light. When a product to be tested passes by, the infrared light is irradiated on the product to be tested and reflected. When the first sensor 31 and the second sensor 32 receive the reflected infrared light, a sensing signal can be generated.

In this embodiment, the second detection module 20, the first sensor 31, the first detection module 10 and the second sensor 32 are sequentially arranged along the extension direction of the conveying device 2. That is, in this embodiment, the product to be tested first passes through the second detection module 20, then passes through the first sensor 31, then passes through the first detection module 10, and finally passes through the second sensor 32 during the conveying process.

The control module 40 is a computer, which can transmit data or signals with the first detection module 10, the second detection module 20, the first sensor 31 and the second sensor 32 by wired or wireless means. In this embodiment, the control module 40 is connected to the first detection module 10 and the second detection module 20 by wired means. The control module 40 is used to control the first shooting device 11 and the second shooting device 21 to take pictures, to control the first light source 12 and the second light source 22 to emit light and control the brightness of the light, to receive the sensing signals of the first sensor 31 and the second sensor 32, and to analyze the captured images to obtain information about the product to be tested.

The following describes the working process of the detection system 1 of this embodiment in conjunction with Figure 8.

When the conveying device 2 conveys the product to be tested, the product to be tested first reaches the second detection module 20. When the product to be tested just reaches the second detection module 20, the detection system 1 does not move. The product to be tested continues to move, and when the product to be tested reaches the first sensor 31, the first sensor 31 can generate a sensing signal. The control module 40 receives the sensing signal and can determine that the product to be tested is facing the second detection module 20 at this time, that is, it controls the second light source 22 to emit light, and controls the second shooting device 21 to shoot an image. The image captured at this time is an image of the label.

The product to be tested has a certain volume, so it takes a certain amount of time from the time when the product to be tested reaches the first sensor 31 to the time when the product to be tested completely leaves the first sensor 31. That is, starting from the moment when the product to be tested reaches the first sensor 31, in the next period of time, the first sensor 31 can continue to generate a sensing signal, and the control module 40 can also continue to receive the sensing signal. When the product to be tested completely leaves the first sensor 31, the first sensor 31 stops generating the sensing signal, and the control module 40 switches from the state of receiving the sensing signal to the state of not receiving the sensing signal. In other words, starting from the moment when the product to be tested reaches the first sensor 31, the first sensor 31 generates a trigger signal until the product to be tested completely leaves the first sensor 31, and the trigger signal stops. The control module 40 can judge that the product to be tested has reached the location of the first detection module 10 according to the switching of the above state, so the control module 40 controls the first light source 12 to emit light and controls the first shooting device 11 to shoot an image. The image captured at this time is an image of the bottle mouth.

The first camera 11 and the second camera 21 are also used to transmit the captured images back to the control module 40. The control module 40 is used to receive the image of the label captured by the second camera 21, and determine the language (e.g., Chinese, English) of the text on the label based on the outline of the text on the label, thereby determining whether the label is misplaced. The control module 40 is also used to receive the image of the bottle mouth captured by the first camera 11, capture the outline of the bottle mouth, and determine whether the shape of the bottle mouth is a preset shape (e.g., circular), whether there is any residual material on the bottle mouth that has not been cut off, whether the bottle mouth is blocked, etc.

When the control module 40 determines that the label is correctly attached, the bottle mouth shape is correct, there is no residual material in the bottle mouth, and the bottle mouth is not blocked, the product to be tested is judged to be qualified, otherwise it is judged that the product to be tested is unqualified.

During the process of the control module 40 analyzing the above-mentioned image, the product to be tested continues to move. The control module 40 can obtain the judgment result before the product to be tested reaches the second sensor 32. When the product to be tested reaches the second sensor 32, the second sensor 32 can generate a sensing signal. The control module 40 is used to receive the sensing signal, and according to the sensing signal, it can be judged that the product to be tested has left the first detection module 10.

If the control module 40 determines that the product to be tested is qualified, when receiving the sensing signal returned by the second sensor 32, no operation is performed on the product to be tested, and the product to be tested can continue to be transmitted to the next processing node by the conveying device 2. If the control module 40 determines that the product to be tested is unqualified, when receiving the sensing signal returned by the second sensor 32, the corresponding structure on the production line is controlled to remove the product to be tested on the conveying device 2 to prevent the unqualified product to be tested from being transmitted to the next processing node. For example, a blowing structure (not shown) is provided on the production line, and the control module 40 can be electrically connected to the blowing structure to control the blowing structure to blow the product to be tested out of the conveying device 2.

FIG9 is an image of the bottle mouth obtained when the camera is facing the product to be tested in a comparative example, and FIG10 is an image of the bottle mouth obtained when the camera is at an offset shooting angle. When the control module receives the image sent back by the camera, it will capture the highlight in the image and use it as the outline of the bottle mouth. Since a ring-shaped light source is used in this comparative example, its illumination range is relatively small. When the shooting angle is offset, the position found by the light on the product to be tested will change, causing the highlighted area in the image to shift away from the position of the bottle mouth. That is, when the shooting angle is offset, in the image obtained by shooting, the highlighted area no longer completely corresponds to the position of the bottle mouth, and the position where a part of the bottle body is located is also highlighted. At this time, the control module captures the highlight in the image as the outline of the bottle mouth, which will lead to a misjudgment of whether the product to be tested is qualified. Moreover, as shown in Figure 10, the inside of the product to be tested (i.e., the inside of the bottle) is also highlighted. At this time, if the highlighted part is captured as the bottle mouth contour, it will also be misjudged as a blocked bottle mouth.

FIG11 is an image of the bottle mouth obtained when the first shooting device 11 of this embodiment is facing the product to be tested, and FIG12 is an image of the bottle mouth obtained when the shooting angle of the first shooting device 11 is offset. It can be seen from FIG11 and FIG12 that since the first light source 12 is a surface light source, a large range of the area where the product to be tested is located is illuminated. Even when the shooting angle is offset, the highlighted part in the image still corresponds to the position of the bottle mouth, and the control module 40 can accurately obtain the outline of the bottle mouth. And according to FIG12, when the shooting angle is offset, only the bottle mouth part is highlighted, and the bottle mouth and the inner part of the bottle are clearly distinguished, so that the misjudgment of the bottle mouth being blocked can be avoided.

The detection system 1 of this embodiment includes a first detection module 10, which includes a first shooting device 11 and a first light source 12, wherein the first light source 12 is a surface light source. During the shooting process of the first shooting device 11, since the first light source 12 is a surface light source, its light emission can maintain uniform brightness in a large area where the product to be tested is located. Even if the shooting angle is offset (that is, the first shooting device 11 is not completely facing the product to be tested), a clear image of the product to be tested can be captured. Therefore, the detection system of this embodiment is conducive to improving the quality of the image of the bottle mouth captured by the first shooting device 11.

Ordinary technical personnel in this technical field should recognize that the above implementation methods are only used to illustrate the present invention, and are not used as limitations on the present invention. As long as they are within the spirit of the present invention, appropriate changes and modifications to the above implementation examples are within the scope of protection required by the present invention.

1: Detection system

10: First detection module

20: Second detection module

30:Sensor module

50: Main body bracket

2: Transmission device

Claims (10)

A detection system, which is improved in that it comprises: a first detection module, comprising a first camera and a first light source, wherein the first camera is used to capture an image of a product to be detected, the first light source is a surface light source, and is used to illuminate the product to be detected when the first camera captures the image of the product to be detected, the first light source comprises a reflector and two light-emitting plates, the reflector comprises two reflective parts, the two reflective parts and the two light-emitting plates are sequentially enclosed to form a cylindrical structure with a hollow space, the two reflective parts are The light part is used to reflect the light from the two light-emitting boards multiple times to maintain uniform brightness in the area where the product to be tested is located; the sensing module is used to generate a sensing signal when sensing the product to be tested; and the control module is respectively connected to the first shooting device, the light-emitting board and the sensing module, and is used to control the light-emitting board to emit light and control the first shooting device to shoot images when receiving the sensing signal. The control module is also used to analyze the image to determine whether the product to be tested is qualified. As described in claim 1, the detection system, wherein each of the light-emitting plates is a surface light source, the two light-emitting plates are arranged in parallel and the light-emitting surfaces of the two light-emitting plates are arranged opposite to each other. A detection system as described in claim 2, wherein the reflective plate is also used to scatter light from the two light-emitting plates. As described in claim 2, the detection system, wherein the two reflective parts are plate-shaped structures each having a reflective surface, the two reflective parts are arranged in parallel and the reflective surfaces are arranged opposite to each other. As described in claim 4, the reflector further includes a connecting portion connected between the two reflective portions, the connecting portion is provided with a through hole, and the first shooting device is located on one side of the connecting portion of the first light source, and is used to shoot the image of the product to be tested through the through hole. The detection system as described in claim 1, wherein the first detection module further includes a light blocking plate, and the light blocking plate is used to block external light. The detection system as described in claim 1, further comprising a second detection module connected to the control module, the second detection module is used to obtain an image of the product to be tested, the first detection module and the second detection module are used to take images of different positions of the product to be tested, and the control module is used to analyze the images obtained by the first detection module and the second detection module to determine whether the product to be tested is qualified. The detection system as described in claim 7, wherein the sensing module includes a first sensor, and when the first sensor senses the product to be tested, the control module controls the second detection module to obtain an image of the product to be tested. The detection system as described in claim 8, wherein when the first sensor senses that the product to be tested leaves the position of the first sensor, the control module controls the first detection module to obtain an image of the product to be tested. The detection system as described in claim 8, wherein the sensing module further includes a second sensor, and when the second sensor senses the product to be tested, the control module outputs a signal to control the removal of the product to be tested.

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