JP2022153154A - Welding visualization system and welding mask with welding visualization system - Google Patents

Abstract

To provide a welding visualization system that can respond to various types of welding.SOLUTION: A welding visualization system includes a camera unit including a plurality of bandpass filters that transmit light in different wavelength bands, and an imaging device that captures images for each different wavelength band of the plurality of bandpass filters, an image processing unit that synthesizes images captured in different wavelength bands, and a display unit that displays the images synthesized by the image processing unit. The plurality of bandpass filters may include a first bandpass filter that transmits light in the ultraviolet band, a second bandpass filter that transmits light in the visible light band, and a third bandpass filter that transmits light in the infrared band.SELECTED DRAWING: Figure 1

Description

One embodiment of the present invention relates to a system for photographing and visualizing the state of welding and a welding mask having the system.

Welding includes arc welding in which arc discharge is generated between the base material and welding rod (wire), and gas welding in which combustible gas such as acetylene and oxygen are burned and the flame melts the base material. . These welds emit rays of radiant heat, so the welds cannot be viewed directly. Normally, the worker applies a welding mask to the face and performs welding while observing the welded part through light-shielding glass. However, visibility through light-shielding glass is poor, making it difficult to see the state of welding, and the actual situation is that the judgment of the quality of welding depends on the experience of the operator.

On the other hand, a system has been disclosed in which the welded part is visualized in real time by photographing the welded part using a camera, instead of having the operator observe the welded part through the light-shielding glass (see Patent Document 1).

JP 2020-189332 A

Arcs and gas flames generated during welding have a high brightness, so if you try to shoot them with a normal camera, the dynamic range is insufficient and the video signal becomes saturated, which is a problem. The welding visualization system disclosed in Patent Literature 1 performs imaging using a neutral density filter in order to deal with this problem. However, since the emission spectrum of the welded part changes depending on the material to be welded and the type of arc welding or gas welding, there is a possibility that the visibility will change if the light is simply dimmed. As a result, there is a problem that an appropriate image cannot be obtained and the welding quality cannot be sufficiently controlled.

In view of such problems, an object of one embodiment of the present invention is to provide a welding visualization system that can respond to various types of welding. It is also an object of the present invention to provide a weld mask with such a weld visualization system.

A welding visualization system according to an embodiment of the present invention includes a camera unit that includes a plurality of bandpass filters that transmit light in different wavelength bands, and an imaging element that captures images for each different wavelength band of the plurality of bandpass filters. , an image processing unit for synthesizing images captured in different wavelength bands, and a display unit for displaying the image synthesized by the image processing unit.

The plurality of bandpass filters include a first bandpass filter that transmits light in the ultraviolet band, a second bandpass filter that transmits light in the visible band, and a third bandpass filter that transmits light in the infrared band. and may include The camera unit has a wavelength conversion unit that converts light in the ultraviolet band into light in the visible light band, the wavelength conversion unit converts light transmitted through the first bandpass filter into visible light, and the imaging device captures can be configured to do so. A filter control unit may be included for sequentially switching between multiple filter units.

A welding visualization system according to an embodiment of the present invention includes a plurality of camera units each including a bandpass filter and an imaging element corresponding to each of the bandpass filters, and image processing for synthesizing the images captured by the plurality of camera units. and a display unit for displaying the image synthesized by the image processing unit.

The plurality of camera units includes: a first camera unit including a first bandpass filter that transmits light in the ultraviolet band; a first imaging device; a second bandpass filter that transmits light in the visible light band; a second camera unit including two imaging elements; a third camera unit including a third bandpass filter that transmits light in the infrared band; and a third imaging element. The first camera unit has a wavelength conversion unit that converts light in the ultraviolet band into light in the visible light band, the wavelength conversion unit converts light transmitted through the first bandpass filter into visible light, and the first imaging element It can be configured to take pictures.

The weld visualization system may be configured such that the image processing unit binarizes the image with a predetermined threshold and weights the data values of the binarized pixels.

The weld visualization system can be attached to the weld mask.

According to one embodiment of the present invention, it is possible to provide a welding visualization system that can respond to various welding conditions by photographing a welded portion by combining a plurality of optical filters that transmit light in a specific wavelength band. .

1 is a block diagram showing the configuration of a welding visualization system according to one embodiment of the present invention; FIG. It is a figure which shows the structure of the camera unit of the welding visualization system which concerns on one Embodiment of this invention. It is a block diagram showing the configuration of the image processing unit of the welding visualization system according to one embodiment of the present invention. FIG. 4 is a diagram schematically showing an emission spectrum of a welded portion and explaining a wavelength band within the spectrum captured by a camera unit; It is a figure explaining the content of the image processing which the image processing unit of the welding visualization system which concerns on one Embodiment of this invention performs. 1 is a block diagram showing the configuration of a welding visualization system according to one embodiment of the present invention; FIG. It is a figure explaining composition of a welding mask which has a welding visualization system concerning one embodiment of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the present invention can be implemented in many different aspects and should not be construed as being limited to the description of the embodiments exemplified below. In order to make the description clearer, the drawings may schematically show the width, thickness, shape, etc. of each part compared to the actual embodiment, but this is only an example and limits the interpretation of the present invention. not a thing In addition, in this specification and each figure, the same reference numerals may be given to the same elements as those described above with respect to the existing figures, and detailed description thereof may be omitted as appropriate. Further, the letters "first" and "second" for each element are convenient labels used to distinguish each element and have no further meaning unless otherwise specified.

[First Embodiment]
FIG. 1 shows a block diagram illustrating the configuration of a welding visualization system 100a according to one embodiment of the present invention. Weld visualization system 100 a includes camera unit 102 , image processing unit 104 , display unit 106 , filter control unit 108 and data storage unit 110 . Camera unit 102 includes image sensor 112 , filter unit 118 , wavelength conversion unit 116 , and lens unit 114 . Filter unit 118 further includes a bandpass filter 1181 . The filter unit 118 may also include an ND filter (neutral density filter) 1182 .

In the welding visualization system 100a, the camera unit 102 photographs the welded portion 200, the image processing unit 104 processes the photographed data, and the display unit 106 displays the image. Camera unit 102 can capture both moving and still images of weld 200 . Display unit 106 includes a display for displaying images captured by camera unit 102 . The display may be a normal direct-view display or a VR (Virtual Reality) display (head-mounted display). The image processing unit 104 also has the function of storing image data in the data storage unit 110 . The filter control unit 108 performs control to appropriately switch between the bandpass filter 1181 and the ND filter 1182 when the camera unit 102 takes an image. The filter control unit 108 performs control to switch between the insertion/non-insertion operation of the wavelength conversion unit in synchronization with the switching operation of the bandpass filter 1181 .

The imaging device 112 used in the camera unit 102 is, for example, a CMOS image sensor. The lens unit 114 preferably has an optical system for projecting an image onto the imaging surface of the imaging device 112, and preferably has a zoom optical system for enlarging and photographing the welded portion 200. FIG. Since the camera unit 102 captures the arc of welding, the combination of the image sensor 112 and the lens unit 114 alone results in saturation of the image. Since the bandpass filter 1181 transmits light in a specific band, the light emitted from the weld 200 is attenuated. An ND filter 1182 may be used to further reduce the light incident on the imaging device 112 .

The camera unit 102 does not simply capture an image of the weld 200, but captures an image of a specific wavelength band. Arcs or gas flames generated in welding are known to have a broad spectrum from the ultraviolet band to the visible and infrared bands. The welding visualization system 100 not only visualizes the welding state but also enables the welding state to be observed in more detail by capturing an image of a specific wavelength band using the band-pass filter 1181 .

The filter unit 118 includes a bandpass filter 1181 that can select multiple wavelength bands. The bandpass filter 1181 includes, for example, a first bandpass filter 1181a that transmits a specific band in the ultraviolet band (wavelength of 380 nm or less), and a second bandpass filter that transmits a specific band in the visible light band (approximately 380 nm to 780 nm). It includes two bandpass filters 1181b and a third bandpass filter 1181c that transmits a specific band in the infrared light band (780 nm or more). The bandpass filter 1181 is not limited to this example, and may include a plurality of bandpass filters having different transmission wavelength bands in each band.

The imaging device 112 is provided with a filter for capturing a color image, and normally has a specification that cannot directly capture ultraviolet light. Therefore, when the first bandpass filter 1181 a described above is selected as the bandpass filter 1181 , the camera unit 102 has a mechanism in which a wavelength conversion unit is inserted between the camera unit 102 and the imaging element 112 . The wavelength conversion unit 116 is configured using a scintillator or phosphor. The operation of the filter unit 118 and the wavelength conversion unit 116 is controlled by the filter control unit 108, and when the first bandpass filter 1181a is selected, the wavelength conversion unit 116 is inserted in front of the image sensor 112 in synchronization with it. be.

FIG. 2 schematically shows the configuration of the camera unit 102. As shown in FIG. The camera unit 102 has a configuration in which a filter unit 118, a wavelength conversion unit 116, a lens unit, and an imaging device 112 are arranged from the light incident side.

Filter unit 118 includes a plurality of bandpass filters 1181 . FIG. 2 shows that the plurality of bandpass filters 1181 includes a first bandpass filter 1181a, a second bandpass filter 1181b, and a third bandpass filter 1181c. The plurality of bandpass filters 1181 have different transmission wavelength bands. For example, the first bandpass filter 1181a transmits light in the ultraviolet band, the second bandpass filter 1181b transmits light in the visible band, and the third bandpass filter 1181c transmits light in the infrared band. The filter unit 118 includes a driving mechanism such that the first bandpass filter 1181a, the second bandpass filter 1181b, and the third bandpass filter 1181c are alternately arranged on the optical path of incident light. Although FIG. 2 shows three bandpass filters with different transmission light bands, the filter unit 118 may include more types of bandpass filters without being limited to this example.

The wavelength conversion unit 116 includes a wavelength conversion element 1161 . The wavelength conversion element 1161 is configured using a scintillator or phosphor as described above. The wavelength conversion element 1161 has a characteristic of converting ultraviolet light into light in the visible light band and radiating the light. The wavelength conversion unit 116 includes a drive mechanism that allows the wavelength conversion element 1161 to be moved in and out of the optical path of incident light. When the first bandpass filter 1181a is placed on the optical path, the wavelength conversion unit 116 arranges the wavelength conversion element 1161 on the optical path in synchronization with this. Such switching of the bandpass filter 1181 and operation of the wavelength conversion unit 116 are controlled by the filter control unit 108 shown in FIG.

When the camera unit 102 takes an image of the welded part, if the first band-pass filter 1181 a is arranged on the optical path of the incident light, the light in the ultraviolet band is transmitted and enters the wavelength conversion element 1161 . The wavelength conversion element 1161 converts light in the ultraviolet band into light in the visible light band, and the converted light enters the imaging element 112 through the lens unit 114 . The camera unit: does not directly capture the ultraviolet component of the arc or gas flame generated during welding, but captures it after converting it into visible light. As a result, it is possible to visually recognize the state of welding, which could not be seen conventionally.

FIG. 3 shows the configuration of the image processing unit 104. As shown in FIG. The image processing unit 104 includes a processor 120 (first processor 120 a, second processor 120 b ), system memory 122 , cache memory 124 , input/output interface 126 and network interface 128 .

The system memory 122 is configured to store programs accessible by the first processor 120a. The program describes a set of instructions that demonstrate the functionality of the weld visualization system. The system memory 122 is composed of non-volatile memory. The first processor 120a reads programs from the system memory 122 and controls operations of the camera unit 102 and the filter unit 118 . The first processor 120a also processes image data output from the camera unit 102, as will be described later. The image processing unit 104 may be provided with a dedicated second processor (GPU) 120b to perform image processing at high speed. The cache memory 124 is used for temporary storage of image data.

The input/output interface 126 has a function of transmitting or receiving data and transmitting control commands to/from the display unit 106, the camera unit 102, the filter control unit 108, and the data storage unit 110. FIG. For example, the input/output interface 126 receives image data from the camera unit 102 . The image data is temporarily stored in the cache memory 124 and processed by the second processor 120b. Image-processed image data is output to the display unit 106 via the input/output interface 126 . Also, image data that has undergone image processing is stored in the data storage unit 110 via the input/output interface 126 .

Image processing unit 104 may include network interface 128 . A network interface 128 is used for connection with a communication network (telecommunication line) such as the Internet. The image processing unit 104 has a function of transmitting image data to the terminal device 130 via the communication network. The image processing unit 104 can output the image captured by the camera unit 102 and processed by the second processor 120b to the terminal device 130 via the communication network. In other words, the terminal device 130 can view images captured by the camera unit 102 via the image processing unit 104 in real time. The image processing unit 104 also has a function of reading image data from the data storage unit 110 and transmitting the image data to the terminal device 130 via the communication network.

The terminal device 130 is a computer device capable of screen display, such as a personal computer, desktop computer, laptop computer, notebook computer, tablet terminal, and smart phone. The welding visualization system 100a can also transmit an instruction from such a terminal device 130 and take an image of the weld with the camera unit 102. FIG.

By the way, the emission spectrum of the weld differs depending on the type and conditions of welding. FIG. 4A shows a schematic example of an emission spectrum in arc welding (for example, MAG (Metal Active Gas) welding using active gas as a shield gas). In arc welding, a large emission spectrum is observed at a wavelength of 550 nm or less, and a particularly strong emission spectrum is observed in the ultraviolet band with a wavelength of 400 nm or less. On the other hand, FIG. 4B schematically shows the spectrum of argon-hydrogen mixed gas arc welding, and characteristic spectra are observed near 480 nm and near 660 nm.

The welding visualization system 100a of the present embodiment does not simply shoot the luminescence of the fusible portion having the spectrum as shown in FIGS. Image data is generated by selecting one or more bands and preferably combining images captured in multiple wavelength bands. For example, as shown in FIG. 4A, the camera unit 102 filters light (ultraviolet light) with a wavelength of 275 to 325 nm by the first bandpass filter 1181a, converts it into visible light by the wavelength conversion element 1161, and takes an image. The first image data captured, the second image data captured by filtering light (visible light) with a wavelength of 550 to 600 nm by the second band-pass filter 1181b, and the light with a wavelength of 775-825 nm by the third band-pass filter 1181c (Near-infrared light) is filtered to generate third image data. In this embodiment, since there is one camera unit 102, the band-pass filter 1181 is switched at high speed to sequentially capture each wavelength band.

Also, in the example shown in FIG. 4B, since the emission spectrum is concentrated in the visible light band, a plurality of bandpass filters are used in the visible light band. For example, in the camera unit 102, a band-pass filter that filters light in the wavelength band of 475-500 nm, a band-pass filter that filters light in the wavelength band of 560-575 nm, and a band-pass filter that filters light in the wavelength band of 650-675 nm. Shoot using a filter.

In this way, by capturing light in a specific wavelength band using a bandpass filter, it is possible to suppress the amount of light incident on the imaging device, and to solve the problem of insufficient dynamic range.

Note that FIGS. 4A and 4B are examples, and the band-pass filter 1181 selects a wavelength band and the number of wavelength bands to be selected is not limited, but a plurality of images can be captured in different wavelength bands. preferable.

5A and 5B show an overview of image processing performed by the image processing unit 104. FIG. The first image data 132 shown in FIG. 5A is image data captured with light in the ultraviolet band, the second image data 134 is image data captured with light in the visible band, and the third image data 136 is infrared light. This is image data taken with a band of light. The image processing unit 104 reads these image data and performs image processing (S201). Then, the three image data are synthesized (S202), and the image is displayed on the display unit (S203). Image data includes both still images and moving images. Although FIG. 5A exemplifies image data of three bands as image data, there is no limitation on the type and number of image data. For example, there may be a plurality of visible band image data, or the ultraviolet band image data may be omitted.

FIG. 5B shows an example of image processing in step S201. In the image processing, first, the image data is binarized using a predetermined threshold value, and the range of the welding area within the image is detected (S2011). Then, the data within the detection range is multiplied by the weighting factor (S2012). For example, image data obtained by photographing a weld having a spectrum as shown in FIG. The brightness of image data in the infrared band is reduced. Therefore, by increasing the brightness of the image data in the visible light band as weighting, it is possible to generate image data with a clear outline after synthesis.

In addition, as shown in FIGS. 4A and 4B, since the brightness varies depending on the wavelength band to be captured, the weighting is performed so that the image data with low brightness becomes bright so that the brightness is leveled. A weight may be applied to darken data with high . By making such adjustments, the condition of the weld can be continuously visualized through the camera unit even when no welding arc is generated.

The welding visualization system 100a according to the present embodiment selects light in a narrow wavelength band according to the emission spectrum of the weld by photographing the weld by combining a plurality of optical filters that transmit light in a specific wavelength band. By photographing, the state of welding can be visualized.

[Second embodiment]
This embodiment shows an example of a welding visualization system 100b in which the configuration of the camera unit 102 is different from that of the first embodiment. In the following explanation, the explanation will focus on the parts that are different from the first embodiment.

FIG. 6 shows the configuration of a welding visualization system 100b according to this embodiment. This welding visualization system 100b has a first camera unit 102a, a second camera unit 102b, and a third camera unit 102c. The first camera unit 102a includes a first imaging device 112a, a first lens unit 114a, a wavelength conversion unit 116, and a first filter unit 118a. The first filter unit 118a includes a first bandpass filter 1181a having a transmission wavelength band in the ultraviolet band. Also, the first filter unit 118a may include a first ND filter 1182a. The first imaging device 112a captures an image that is transmitted through the first bandpass filter 1181a and wavelength-converted into visible light by the wavelength conversion unit.

The second camera unit 102b includes a second imaging element 112b, a second lens unit 114b, and a second filter unit 118b. The second filter unit 118b includes a second bandpass filter 1181b having a transmission wavelength band in the visible light band. Also, the second filter unit 118b may include a second ND filter 1182b. The third camera unit 102c includes a third imaging element 112c, a third lens unit 114c, and a third filter unit 118c. The third filter unit 118c includes a third bandpass filter 1181c having a transmission wavelength band in the infrared band. Also, the third filter unit 118c may include a third ND filter 1182c.

Thus, the welding visualization system 100b according to the present embodiment has camera units that capture images in respective wavelength bands of the ultraviolet band, the visible light band, and the infrared band. This makes it possible to capture images of each wavelength band at the same time, so that images (still images and moving images) of the welded portion 200 can be obtained in a clearer state. Also, since the optical filters of the first camera unit 102a, the second camera unit 102b, and the third camera unit 102c are fixed, the filter switching unit can be omitted.

A welding visualization system 100b according to the present embodiment is the same as the welding visualization system 100a according to the first embodiment except for the configuration of the camera unit, and can obtain the same effects.

[Third Embodiment]
This embodiment shows an example of a weld mask 150 with a weld visualization system. As an example, this embodiment shows a welding mask 150 equipped with the welding visualization system 100b shown in the second embodiment.

FIG. 7A shows a welding mask 150 according to this embodiment. Weld mask 150 has weld visualization system 100b attached to protective surface 152 . Welding mask 150 has camera units 102 (first camera unit 102a, second camera unit 102b, and third camera unit 102c) attached at positions corresponding to eye level when worn on the face. Since the camera unit 102 can shoot moving images in real time, the worker can work with a normal line of sight.

FIG. 7B shows the configuration of the welding visualization system 100c attached to the welding mask 150. As shown in FIG. The welding visualization system 100b includes a first camera unit 102a, a second camera unit 102b, and a third camera unit 102c, which are arranged on the front side of the welding mask 150, from the head, back, sides, or chin of the welding mask 150. It includes an image processing unit 104 installed at a low position, and a display unit 106 installed at eye level inside the welding mask 150 . Since the display unit 106 is placed close to the face, it is preferably a goggle type display (VR display). The display unit 106 may be fixed inside the welding mask 150, or may be a head-mounted display that is separate from the welding mask 150 and directly worn by the operator.

By using the welding mask 150 according to this embodiment, the operator can visually confirm the welding state in real time. In addition, by capturing an image in real time with the camera unit 102 and displaying it on the display system, the worker can put on and take off the welding mask each time the welding work (the work of actually generating an arc to perform welding) is performed. Since it is not necessary, welding can be performed continuously, and workability can be improved.

Although this embodiment shows an example in which the welding visualization system 100b according to the second embodiment is attached to the welding mask 150, the welding visualization system 100a according to the first embodiment can be similarly applied. .

The welding visualization system 100a according to the first embodiment and the welding visualization system 100b according to the second embodiment can be applied to welding robots. That is, by analyzing the clear image captured by the camera unit 102, the welding robot can be precisely controlled. In addition, by equipping the welding robot with artificial intelligence and making it learn images of the welding performed by a skilled worker, the welding robot can take over the welding technique of the skilled worker.

100: welding visualization system, 102: camera unit, 102a: first camera unit, 102b: second camera unit, 102c: third camera unit, 104: image processing unit, 106: display unit, 108: filter control unit, 110 : data storage unit, 112: image sensor, 112a: first image sensor, 112b: second image sensor, 112c: third image sensor, 114: lens unit, 114a: first lens unit, 114b: second lens unit, 114c: third lens unit, 116: wavelength conversion unit, 1161: wavelength conversion element, 118: filter unit, 118a: first filter unit, 118b: second filter unit, 118c: third filter unit, 1181: bandpass filter , 1181a: first bandpass filter, 1181b: second bandpass filter, 1181c: third bandpass filter, 1182: ND filter, 1182a: first ND filter, 1182b: second ND filter, 1182c: third ND filter, 120: Processor, 122: System memory, 124: Cache memory, 126: Input/output interface, 128: Network interface, 130: Terminal device, 132: First image data, 134: Second image data, 136: Third image data, 150 : welding mask, 152: protective face, 200: welding part

Claims (10)

a camera unit that includes a plurality of bandpass filters that transmit light of different wavelength bands, and an imaging element that performs imaging for each different wavelength band of the plurality of bandpass filters;
an image processing unit that synthesizes the images captured for each of the different wavelength bands;
a display unit that displays an image synthesized by the image processing unit;
A welding visualization system comprising: The plurality of bandpass filters include a first bandpass filter that transmits light in the ultraviolet band, a second bandpass filter that transmits light in the visible band, and a third bandpass filter that transmits light in the infrared band. 3. The weld visualization system of claim 1, comprising a filter. The camera unit has a wavelength conversion unit that converts light in the ultraviolet band to light in the visible light band,
3. The welding visualization system according to claim 2, wherein said wavelength conversion unit converts light transmitted through said first band-pass filter into visible light, and said imaging device photographs. 4. The weld visualization system according to any one of claims 1 to 3, comprising a filter control unit for sequentially switching said plurality of filter units. a plurality of camera units each including a bandpass filter and an imaging element corresponding to each of the bandpass filters;
an image processing unit that synthesizes images captured by the plurality of camera units;
a display unit that displays an image synthesized by the image processing unit;
A welding visualization system comprising: The plurality of camera units are
a first camera unit including a first bandpass filter that transmits light in the ultraviolet band and a first imaging element;
a second camera unit including a second bandpass filter that transmits light in the visible light band and a second imaging element;
a third camera unit including a third bandpass filter that transmits light in the infrared band and a third imaging element;
6. The weld visualization system of claim 5, comprising: the first camera unit has a wavelength conversion unit that converts light in the ultraviolet band to light in the visible light band;
7. The welding visualization system according to claim 6, wherein said wavelength conversion unit converts light transmitted through said first band-pass filter into visible light, and said first imaging device photographs. 8. Welding visualization system according to any one of claims 5 to 7, wherein the display unit displays images in situ. 9. The weld visualization system of any one of claims 1 to 8, wherein the image processing unit binarizes the image with a predetermined threshold and weights the binarized pixel data values. A weld mask comprising a weld visualization system according to any one of claims 1-9.

Images