Same view multi-signal synchronous monitoring system and method

Abstract

This invention relates to a simultaneous multi-signal monitoring system and method from the same viewing angle. It addresses the technical problems of existing technologies for monitoring objects such as bubbles, arcs, and droplets in underwater wet welding / additive processes, which suffer from low stability and reliability when using high-speed cameras to acquire images. These problems include difficulty in accurately and stably distinguishing the slag-molten metal interface, difficulty in clearly characterizing the droplet transition process, and difficulty in synchronously analyzing droplet transition, molten pool interface changes, bubble behavior, and arc radiation status under a unified time reference and observation perspective. The system includes an X-ray observation module, an optical monitoring module, and a controller. X-ray images and high-speed optical images are acquired synchronously from the same viewing angle. Optical radiation entering the optical monitoring channel is transmitted to the high-speed camera in the target band to form a high-speed image, while non-target band radiation is reflected to the spectral acquisition probe and input into the spectrometer to form spectral information. This invention improves the spatial consistency, synchronicity, and completeness of monitoring underwater wet arc welding / additive processes and onshore arc welding / additive processes.

Description

Technical Field

[0001] This invention relates to the field of welding / additive manufacturing process monitoring technology, and more specifically, to a multi-signal synchronous monitoring system and method from the same viewing angle. Background Technology

[0002] With the continuous development of underwater welding technology, underwater welding has been widely used in marine engineering, ship repair, and deep-sea pipeline maintenance. Underwater wet welding technology has been widely adopted due to its advantages such as low cost, fewer restrictions on workpiece shape and joint type, and fewer supporting equipment requirements.

[0003] However, in underwater wet welding, the transition of bubbles, arcs, and droplets is unstable, which is detrimental to weld formation and joint reliability. Therefore, it is necessary to improve the instability of bubble, arc, and droplet transitions, and monitoring these transitions is a necessary means to achieve this improvement. Referring to the invention patent application with publication number CN109926693A, which discloses a technical solution for monitoring by acquiring images with a high-speed camera, although it can reflect the appearance of the arc and bubbles, it is easily affected by arc saturation, water scattering, and bubble obstruction, resulting in low stability and reliability. In addition, it is often difficult to accurately and stably distinguish details such as the interface between slag and molten metal, and it is difficult to clearly characterize the droplet transition process. Furthermore, it is difficult to simultaneously analyze droplet transition, molten pool interface changes, bubble behavior, and arc radiation state under a unified time reference and the same observation perspective. Summary of the Invention

[0004] This application aims to address the technical problems of existing technologies for monitoring bubble behavior, arc appearance, droplet transfer, and molten pool interface changes during underwater wet welding. These problems include low stability and reliability when using high-speed cameras to acquire images, difficulty in accurately and stably distinguishing the slag-molten metal interface, difficulty in clearly characterizing the droplet transfer process, and difficulty in simultaneously analyzing droplet transfer, molten pool interface changes, bubble behavior, and arc radiation state under a unified time reference and observation perspective. This application provides a multi-signal synchronous monitoring system and method that integrates X-ray, optical signals, and spectral information from the same perspective.

[0005] This application introduces a beam splitting structure into the main X-ray channel, separating and reversing the optical radiation of the welding area from the coaxial optical path and directing it into the optical monitoring channel without altering the X-ray imaging link. This achieves simultaneous acquisition of X-ray images and high-speed optical images from the same viewpoint. For the optical radiation entering the optical monitoring channel, the target wavelength is transmitted into the high-speed camera to form a high-contrast, high-speed image, while non-target wavelength radiation is reflected to the spectral acquisition probe and input into the spectrometer for synchronous diagnosis of arc radiation spectra. After multi-channel synchronous acquisition, the controller can perform time alignment of the X-ray image sequence, high-speed optical image sequence, and spectral sequence based on timestamps, and establish a spatial correspondence between the X-ray images and the optical images. Based on this, the controller can perform synchronous correspondence analysis and joint analysis of droplet transfer, molten pool interface changes, arc morphology, bubble behavior, molten pool surface morphology, weld bead or forming contour changes, and arc radiation changes, obtaining the temporal correspondence, spatial correspondence, and trends between different features. This application is applicable to a variety of environments and / or any observable object. It can be used for observing underwater wet arc welding processes, underwater wet arc additive manufacturing processes, and also for observing arc welding and arc additive manufacturing processes in non-underwater environments. Among these, underwater wet welding / additive manufacturing is one of the key application scenarios.

[0006] This application provides a multi-signal synchronous monitoring system with the same viewing angle, including an X-ray observation module, an optical monitoring module, and a controller; The X-ray observation module includes an X-ray source, a first optical path adjustment mechanism, an image receiver, and a first high-speed camera. The first high-speed camera is connected to the image receiver, which is located on one side of the first optical path adjustment mechanism. The optical monitoring module includes a background laser source, a background laser emitter, a spectrometer, a spectral acquisition probe, a second optical path adjustment mechanism, a second high-speed camera, and a bandpass filter, which is located in front of the second high-speed camera. The spectral acquisition probe and the spectrometer are connected and communicate with each other. The background laser emitter is connected to the background laser source. The first optical path adjustment mechanism is used to allow the X-rays emitted from the X-ray source and passing through the welding area to enter the image receiver, and at the same time deflect the optical radiation generated from the welding area irradiated by the laser output head to the second optical path adjustment mechanism. The No. 2 optical path adjustment mechanism is used to divide the optical radiation into two parts: target band light and non-target band light. The target band light is sent to the No. 2 high-speed camera through the bandpass filter, and the non-target band light is sent to the spectrum acquisition probe through the other path. The X-ray source, image receiver, high-speed camera No. 1, and high-speed camera No. 2 are respectively connected to the controller for communication; High-speed camera No. 1, high-speed camera No. 2, and spectrometer synchronously perform data acquisition under the control of the controller.

[0007] Preferably, the first optical path adjustment mechanism includes a beam splitter and a beam splitter positioning device, with the beam splitter connected to the beam splitter positioning device.

[0008] Preferably, the second optical path adjustment mechanism includes a dichroic mirror and a dichroic mirror positioning device, wherein the dichroic mirror is connected to the dichroic mirror positioning device.

[0009] Preferably, the beam splitter is arranged at a -45° tilt angle, and the dichroic mirror is arranged at a +45° tilt angle.

[0010] Preferably, the beam splitter positioning device includes an X-axis linear module, a Y-axis linear module, a Z-axis linear module, a support plate, a lens rotation drive motor, a harmonic reducer, and a lens clamp. The Y-axis linear module is connected to the X-axis linear module, the Z-axis linear module is connected to the Y-axis linear module, and the support plate is connected to the Z-axis linear module. The lens rotation drive motor, the harmonic reducer, the lens clamp, and the clamp support are all connected to the support plate. The lens clamp is rotatably connected to the clamp support. The output shaft of the lens rotation drive motor is connected to the input end of the harmonic reducer. The output end of the harmonic reducer is connected to one end of the lens clamp, and the rotation of the output end of the harmonic reducer drives the lens clamp to rotate. The beam splitter is connected to the lens clamp.

[0011] Preferably, the multi-signal synchronous monitoring system with the same viewing angle is configured to monitor the underwater wet arc welding process, the underwater wet arc additive manufacturing process, the onshore arc welding process, or the onshore arc additive manufacturing process.

[0012] Preferably, the same-view multi-signal synchronous monitoring system further includes a lead room, where the X-ray source, the first optical path adjustment mechanism, the image receiver, the first high-speed camera, the second optical path adjustment mechanism, the second high-speed camera, the bandpass filter, the background laser emitter, and the spectral acquisition probe are all located inside the lead room; the controller, the spectrometer, and the background laser source are located outside the lead room; the background laser source is connected to the background laser emitter via a first optical fiber, which passes through the lead room; the spectral acquisition probe is connected to the spectrometer via a second optical fiber, which also passes through the lead room; the X-ray source, the image receiver, the first high-speed camera, and the second high-speed camera are each connected to the controller via cables, which also pass through the lead room.

[0013] Preferably, the same-view multi-signal synchronous monitoring system further includes a lead room, where the X-ray source, the first optical path adjustment mechanism, the image receiver, the first high-speed camera, the second optical path adjustment mechanism, the background laser emitter, and the spectral acquisition probe are all located inside the lead room; the controller, the spectrometer, and the background laser source are located outside the lead room; the background laser source is connected to the background laser emitter via a first optical fiber, which passes through the lead room; the spectral acquisition probe is connected to the spectrometer via a second optical fiber, which also passes through the lead room. The X-ray source, image receiver, and high-speed camera No. 1 are connected to the controller via cables, which pass through the lead room. The second high-speed camera and bandpass filter are located outside the lead room. The lead room is equipped with an observation window that matches the second high-speed camera. The second high-speed camera is connected to the controller via a cable.

[0014] Preferably, the beam splitter includes an incident-side functional protective layer, an optical reflective layer, an X-ray transmission substrate layer, and an exit-side functional protective layer.

[0015] Preferably, the thickness of the X-ray transmission substrate is 0.25 mm, the thickness of the optical reflection layer is 100 nm, and the thickness of the emission-side functional protective layer is 80-150 nm.

[0016] This application also provides a monitoring method using a multi-signal synchronous monitoring system with the same viewing angle. The controller analyzes the data collected by the first high-speed camera, the second high-speed camera, and the spectrometer to evaluate the monitored object.

[0017] Preferably, the controller evaluates one or more of the following characteristics of the monitored object: droplet transfer behavior, molten pool interface changes, arc appearance, weld bead profile, forming profile, bubble behavior under specific conditions, and arc radiation characteristics, based on data collected by the No. 1 high-speed camera, the No. 2 high-speed camera, and the spectrometer.

[0018] The beneficial effects of this application are: (1) Acquire information from multiple sources simultaneously from the same perspective to improve spatial consistency and relevance.

[0019] It enables the simultaneous acquisition of X-ray high-speed imaging, optical high-speed imaging, and spectral information from the same viewpoint, and the controller aligns them based on timestamps. This reduces parallax and registration errors caused by multi-camera, multi-directional arrangement, and allows droplet transition, molten pool behavior, arc appearance changes, and bubble evolution under specific conditions to be analyzed within the same field of view.

[0020] (2) Complementary observation capabilities that take into account both the internal processes of the molten pool and the evolution of the bubble interface.

[0021] The X-ray channel utilizes the attenuation differences caused by variations in material density and thickness to create grayscale contrast, providing a stronger ability to distinguish the interface between molten metal and slag. It also allows observation of the penetration process, such as the movement and merging of molten droplets within the slag. The optical imaging channel is more sensitive to changes in arc morphology and bubble contours, enabling the acquisition of information on interface evolution, including bubble formation, expansion, contraction, and rupture. The two channels complement each other, allowing for the simultaneous acquisition of information that a single channel might struggle to capture.

[0022] (3) Introduce spectral diagnostics to improve the ability to distinguish process states.

[0023] By synchronously acquiring arc radiation characteristics through the spectral acquisition channel, it can serve as an indicator of welding stability, arc zone energy input fluctuations, and process anomalies. Combined with high-speed optical imaging information, it can simultaneously obtain target band imaging information and arc radiation spectral information from the same perspective and time reference, reducing the interference of background light on spectral measurements and improving the imaging signal-to-noise ratio and the effectiveness of spectral diagnosis. This is beneficial for improving the ability to identify and interpret changes in process state.

[0024] (4) Reduce the dependence on imaging conditions and improve the stability and applicability of monitoring.

[0025] By entrusting key characterization tasks such as distinguishing the internal processes and interfaces of the molten pool to the X-ray channel, while retaining the advantages of the optical imaging channel for bubble interfaces, the dependence on a single imaging condition is reduced at the system level, thereby improving the monitoring stability in complex underwater environments.

[0026] (5) Facilitates modular integration and maintenance expansion.

[0027] By using a split-path and modular arrangement, different sensor channels can be integrated relatively independently into the same observation system without changing the geometric axis of the X-ray imaging link. This makes it easy to add / replace high-speed cameras or spectral acquisition units without affecting the main imaging link.

[0028] (6) An optical path adjustment mechanism is adopted to make the spatial position and attitude of the beam splitter and the dichroic mirror adjustable. The optical path alignment and stability can be completed during the installation and debugging stage, which meets the system requirements of splitting the same view and synchronous acquisition.

[0029] Further features and aspects of the present invention will be clearly described in the following detailed description with reference to the accompanying drawings. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of a multi-signal synchronous monitoring system with the same viewing angle used in underwater wet welding processes; Figure 2 This is a schematic diagram of the welding device; Figure 3This is a schematic diagram of the X-ray source observation module; Figure 4 This is a structural diagram of the optical monitoring module and a diagram showing its positional relationship with the X-ray source observation module; Figure 5 This is a structural diagram of the No. 1 optical path adjustment mechanism; Figure 6 This is a schematic diagram of the beam splitter.

[0031] Explanation of symbols in the diagram: 1. Welding torch, 2. Motion actuator, 3. Welding machine, 4. Controller, 5. X-ray source, 6. First optical path adjustment mechanism, 7. Image receiver, 8. First high-speed camera, 9. Background laser source, 10. Spectrometer, 11. Background laser output head, 12. Spectrum acquisition probe, 13. Second optical path adjustment mechanism, 13-1. Dichroic mirror, 14. Second high-speed camera, 15. Bandpass filter, 16. Lead room, 17. X-axis linear module, 18. Y-axis linear module, 19. Z-axis linear module, 20. Support plate, 21. Lens rotation drive motor, 22. Harmonic reducer, 23. Lens clamp, 23-1. Clamp bracket, 24. Beam splitter. Detailed Implementation

[0032] The specific embodiments described below are merely preferred embodiments of this application, and the scope of protection of this application is not limited thereto. Those skilled in the art can make modifications or variations based on the principles, concepts, and spirit of this application, and the resulting technical solutions should all be covered within the scope of protection of this application.

[0033] Example 1

[0034] like Figure 1-5 As shown, the multi-signal synchronous monitoring system for underwater wet welding process includes an X-ray observation module and an optical monitoring module. The optical monitoring module and the X-ray observation module are combined to monitor the underwater wet welding process.

[0035] The X-ray observation module includes an X-ray source 5, a primary optical path adjustment mechanism 6, an image receiver 7, and a primary high-speed camera 8. The optical monitoring module includes a background laser source 9, a spectrometer 10, a background laser output head 11, a spectral acquisition probe 12, a secondary optical path adjustment mechanism 13, a secondary high-speed camera 14, and a bandpass filter 15. The bandpass filter 15 is located in front of the lens of the secondary high-speed camera 14.

[0036] The welding device includes a welding torch 1, a motion actuator 2, a welding machine 3, and a controller 4.

[0037] The lead room 16 is a protective structure for shielding X-rays. The area to be welded, the X-ray source 5, the image receiver 7, and the first optical path adjustment mechanism 6 and the second optical path adjustment mechanism 13 are all located inside the lead room 16. The welding machine 3, the controller 4, the spectrometer 10, and the background laser source 9 are located outside the lead room 16. The welding machine 3 is connected to the welding torch 1 and the motion actuator 2 via cables that pass through the lead room 16. The background laser source 9 is connected to the background laser output head 11 via optical fiber. Fiber optic wall-penetrating interfaces are provided on the lead room 16, and the optical fibers are connected to each other via these interfaces. The spectral acquisition probe 12 is connected to the spectrometer 10 via an optical fiber passing through the lead room 16. Fiber optic wall-penetrating interfaces for connecting this optical fiber are provided on the lead room 16. The controller 4 is connected to the X-ray source 5, the motion actuator 2, the first optical path adjustment mechanism 6, the image receiver 7, and the first high-speed camera 8 via cables that pass through the lead room 16.

[0038] The No. 1 high-speed camera 8 is installed inside the lead room 16. The No. 1 high-speed camera 8 is located on the signal output side of the image receiver 7 and is used to collect the X-ray image signal output by the image receiver 7 to ensure the spatial continuity and signal coupling stability of the X-ray imaging link.

[0039] The second high-speed camera 14 is installed inside the lead room 16. It is best to take radiation protection measures for the second high-speed camera 14, including but not limited to installing a local shielding cover on its outside, using radiation-resistant material to protect the housing, adding a lead glass observation window, or using a replaceable protective cover, so as to reduce the impact of scattered rays on camera imaging and device lifespan.

[0040] The first optical path adjustment mechanism 6 is used to achieve adjustable spatial position and orientation of the optical components. Figure 5As shown in the example, the optical path adjustment mechanism includes: an X-axis linear module 17, a Y-axis linear module 18, a Z-axis linear module 19, a carrier plate 20, a lens rotation drive motor 21, a harmonic reducer 22, and a lens clamp 23. The Y-axis linear module 18 is connected to the slider of the X-axis linear module 17, the Z-axis linear module 19 is connected to the slider of the Y-axis linear module 18, and the carrier plate 20 is connected to the slider of the Z-axis linear module 19. The X-axis linear module 17 and the Y-axis linear module 18 enable two-dimensional translation of the beam splitter 24 in the horizontal plane, while the Z-axis linear module 19 enables vertical adjustment of the beam splitter 24. The lens rotation drive motor 21, harmonic reducer 22, lens clamp 23, and clamp bracket 23-1 are all mounted on the support plate 20. The lens clamp 23 is rotatably connected to the clamp bracket 23-1 (one end of the lens clamp 23 is rotatably connected to the clamp bracket 23-1, and the other end of the lens clamp 23 is rotatably connected to the clamp bracket 23-1). The output shaft of the lens rotation drive motor 21 is connected to the input end of the harmonic reducer 22, and the output end of the harmonic reducer 22 is connected to one end of the lens clamp 23 to drive the lens clamp 23 to rotate (the rotation of the output end of the harmonic reducer 22 drives the lens clamp 23 to rotate). The beam splitter 24 is connected to the lens clamp 23, and the rotation of the lens clamp 23 drives the beam splitter 24 to achieve tilt adjustment around a predetermined axis. The motor, in conjunction with a harmonic reducer, drives the lens clamp to achieve high-precision setting and stable holding of micro-angles.

[0041] The first optical path adjustment mechanism 6 is used to clamp and precisely position the beam splitter 24. Without changing the geometric axis of the X-ray main channel, the beam splitter 24 separates the light emitting the optical radiation signal from the welding area from the main optical path and deflects it by 90° into the optical monitoring channel, while allowing the X-ray to pass through along the original direction, thereby providing the same viewing angle and time reference for X-ray imaging and optical imaging.

[0042] The structure of the second optical path adjustment mechanism 13 is basically the same as that of the first optical path adjustment mechanism 6. The difference is that the second optical path adjustment mechanism 13 is used to position the dichroic mirror 13-1, and the lens clamp in the second optical path adjustment mechanism 13 holds the dichroic mirror 13-1. The positioning dichroic mirror 13-1 in the second optical path adjustment mechanism 13 is used to perform secondary splitting of the beam after being refracted by the beam splitter 24 without changing the imaging angle and time reference of the second high-speed camera 14, so as to realize the function of transmission imaging of the target band and acquisition of reflection spectrum of other bands. Specifically, the dichroic mirror 13-1 is positioned near the principal optical axis of the second high-speed camera 14 at a +45° tilt angle, so that the composite radiation from the welding area first enters the dichroic mirror 13-1. The dichroic mirror 13-1 has high transmission characteristics for the target wavelength band light of 808nm. The transmitted light enters the bandpass filter 15 along the original direction. The bandpass filter 15 allows the light of 808nm wavelength to pass through. After passing through the bandpass filter 15, the light of 808nm wavelength finally reaches the second high-speed camera 14, thereby ensuring that the second high-speed camera 14 obtains a high-contrast high-speed image with the 808nm target wavelength band as the main component. At the same time, the dichroic mirror 13-1 has high reflectivity characteristics for non-target wavelength band light, so that the non-target wavelength band light can be guided to the spectral acquisition probe 12 by a 90° deflection, and then enter the spectrometer 10 through optical fiber or optical path connection to realize synchronous acquisition of radiation spectrum. The spectral acquisition probe 12 is equipped with an acquisition optical system, and an aperture is set at its image plane or equivalent image plane to define the sampling area, thereby achieving local spectral acquisition of arc radiation and suppressing background stray light. The second optical path adjustment mechanism 13, through its translation and attitude adjustment capabilities, enables the precise setting and maintenance of the dichroic mirror 13-1 in spatial position, incident angle, and reflection / emission direction. This ensures that the imaging optical path of the second high-speed camera and the spectral acquisition optical path do not obstruct or interfere with each other, and forms a system-level optical path matching relationship with the first optical path adjustment mechanism 6 below, enabling simultaneous observation from the same viewing angle and through multiple channels. Furthermore, the design of the second optical path adjustment mechanism 13 allows for rapid adaptation when switching between different target wavelengths by simply replacing the corresponding dichroic mirror and bandpass filter, thus ensuring effective imaging and spectral acquisition of the system in different wavelengths.

[0043] The working process of the above-mentioned multi-signal synchronous monitoring system for underwater wet welding is described below: First, the workpiece to be welded is clamped and fixed on the motion actuator 2. The relative position of the welding torch 1 and the workpiece, the welding posture, and the welding gap are adjusted so that the area to be welded is in the predetermined welding position inside the lead room 16. Then, it is confirmed that the X-ray source 5, image receiver 7, first optical path adjustment mechanism 6, second optical path adjustment mechanism 13, and second high-speed camera 14 are all installed in the observation position inside the lead room 16. The welding machine 3, controller 4, background laser source 9, and spectrometer 10 are arranged outside the lead room 16 and reliably connected to the equipment inside the lead room 16 through cable / fiber optic wall interfaces. The first high-speed camera 8 is set inside the lead room 16 and located on the signal output side of the image receiver 7. It is optically coupled to the image receiver 7 through lens coupling or fiber optic cones, thereby forming a stable X-ray imaging link.

[0044] Before observation begins, the beam splitter 24 is precisely aligned using the first optical path adjustment mechanism 6: the beam splitter 24 is translated two-dimensionally in the horizontal plane using the X-axis linear module 17 and the Y-axis linear module 18, so that the beam splitter 24 is placed on the main optical path between the welding area and the image receiver 7; the height of the beam splitter 24 is adjusted using the Z-axis linear module 19, so that the radiation center of the welding area falls within the effective light-transmitting aperture of the lens (this is the preferred method); then the lens rotation drive motor 21 drives the lens clamp 23 through the harmonic reducer 22 to finely adjust the tilt angle of the beam splitter 24 and lock it at around -45°, so that the optical signal emitted from the welding area is deflected by the beam splitter 24 into the optical monitoring channel, while the X-rays are transmitted along the original direction into the image receiver 7. Subsequently, the second optical path adjustment mechanism 13 is aligned so that the dichroic mirror 13-1 is in the optical path of the refracting beam. Through translation and attitude adjustment, the dichroic mirror 13-1 is adjusted to a working angle of +45°, allowing light with a wavelength of 808nm to pass through the bandpass filter 15 and reach the second high-speed camera 14. Simultaneously, light of other wavelengths is reflected and guided to the spectral acquisition probe 12, and then input to the spectrometer 10 via optical fiber. After the alignment is completed, the background laser source 9 is turned on, and the background laser output head 11 emits a laser with a wavelength of 808nm. The 808nm laser irradiates the welding area, generating optical radiation. The output power and irradiation position are adjusted so that the second high-speed camera 14, under the action of the bandpass filter 15, obtains an image of light with a wavelength of 808nm. At the same time, the operating parameters of the spectrometer 10 are set to ensure effective acquisition of the arc radiation spectrum.

[0045] Upon entering the synchronous observation and welding stage, controller 4 first sets the high voltage and tube current of X-ray source 5, and sets the exposure / frame rate and trigger mode for image receiver 7 and its coupled high-speed camera 8; simultaneously, it sets the frame rate, exposure, and trigger mode for high-speed camera 14, and sets the sampling mode of spectrometer 10 to be synchronized with the cameras. Then, controller 4 sends a unified synchronous trigger signal, causing high-speed camera 8 to acquire the X-ray imaging sequence output by image receiver 7, high-speed camera 14 to acquire the image sequence of light with a wavelength of 808nm, and spectrometer 10 to simultaneously acquire radiation spectral data of other wavelengths, thus ensuring that multi-channel data correspond under the same time reference. After completing the synchronous trigger settings, welding machine 3 is started and the arc is ignited. The motion actuator 2 drives the welding process according to a preset trajectory or preset speed, and the welding area is continuously and synchronously observed under three channels: X-ray, target band optical high-speed imaging, and spectral analysis.

[0046] After welding, welding machine 3, background laser source 9 and X-ray source 5 are turned off in sequence, and the synchronization data of high-speed camera 8, high-speed camera 14 and spectrometer 10 are saved. Controller 4 aligns the three data streams according to the timestamp of the synchronization trigger signal to achieve joint analysis of multiple signals from the same perspective. This is used to extract key process information such as droplet transition behavior, bubble evolution, molten pool dynamics and arc plasma radiation characteristics, thereby providing data support for underwater wet welding process monitoring and process diagnosis.

[0047] The obtained X-ray images are used to extract the internal processes of the molten pool and the characteristics of the molten metal-slag interface. The molten metal region and the slag region can be segmented using methods such as grayscale thresholding, edge detection, or region growing, and information such as interface location, interface fluctuations, and droplet entry trajectory into the pool can be obtained. For the molten metal region and the slag region, the grayscale difference and noise level of the two regions are calculated to characterize the "clarity" of the interface in the image and its stable segmentation capability. The strength and stability of interface perturbation are evaluated based on the continuous interface locations in the X-ray image sequence. The slag region is segmented in the X-ray images, and the proportion of the slag area to the molten pool region is statistically analyzed to assess the degree of slag coverage. The relative positional relationship and morphological evolution of the droplets and the molten pool are identified in the X-ray image sequence, thereby achieving a quantitative assessment of the droplet transition behavior.

[0048] The images acquired by the second high-speed camera 14 are visible light images. The obtained 808nm wavelength light images are used to extract bubble interface and arc appearance features: information such as bubble contour, size, period and rupture event are obtained through imaging and contour segmentation, which serve as parameters for evaluating bubble behavior.

[0049] Radiation spectral information is used to extract arc radiation characteristics: characteristic bands or spectral lines are selected from the spectral data, and the stability and abnormal fluctuations of the arc are characterized based on the bands and spectral lines.

[0050] Under the same time reference, the "bubble, arc, and droplet transition" are correlated and analyzed for comprehensive evaluation and discrimination. Controller 4 aligns the three data streams according to the timestamp of the synchronous trigger signal, ensuring they correspond under the same time reference. Since the X-ray channel and optical channel share the same viewpoint, a spatial mapping relationship between the two images is established during the installation and commissioning phase, thereby mapping the molten pool / slag region in the X-ray image and the bubble / arc region in the optical image to the same reference coordinate system.

[0051] It should be noted that the installation position of the second high-speed camera 14 can also be set outside the lead room 16, and the corresponding bandpass filter 15 is also set outside the lead room 16. In this case, an observation window is set in the lead room 16, and the optical high-speed image of the welding area is obtained through the observation window on the lead room 16.

[0052] Regarding the beam splitter 24, please refer to... Figure 6 One specific structure of the beam splitter 24 is a multi-layered composite beam splitter window structure, which, from the incident side to the exit side, sequentially includes an incident-side functional protective layer 24-1, an optical reflective layer 24-2, an X-ray transmission substrate layer 24-3, and an exit-side functional protective layer 24-4. The X-ray transmission substrate layer 24-3, serving as the carrier layer for X-ray transmission, preferably has a thickness of 0.25 mm. The material of the X-ray transmission substrate layer 24-3 is preferably Be, to balance X-ray transmittance with the overall rigidity and assembly reliability of the lens under a 120 kV X-ray source. The optical reflective layer 24-2 can form stable high reflectivity for 808 nm light, and its thickness is much smaller than that of the Be substrate layer, preferably 100 nm, so the additional attenuation caused by X-ray transmission is negligible. The material of the optical reflective layer 24-2 is preferably Al. The thickness of the emission-side functional protective layer 24-4 is preferably 80–150 nm, and the material of the emission-side functional protective layer is preferably SiO2, which can provide barrier protection for the back side of the Be substrate and improve its resistance to moisture and heat and corrosion.

[0053] To enhance the target wavelength band λ0, the incident-side functional protective layer 24-1 is preferably made of SiO2. Besides protecting the Al optical reflective layer 24-2 from moisture and oxidation, the incident-side functional protective layer 24-1 also serves as an interference functional layer, with an approximate quarter-wavelength optical thickness. Considering that the beam splitter 24 operates at -45° and the refractive index of SiO2 is approximately 1.45, the internal refraction angle is approximately 29.2°. Therefore, the quarter-wavelength physical thickness can be calculated as t≈λ0 / (4n·cosθ). t ) calculate, where λ0 = 808 nm, n ≈ 1.45, cosθ t≈0.873. When λ0=808 nm, t≈160 nm is obtained. Therefore, the incident side functional protective layer 24-1 of SiO2 material is preferably about 160 nm thick, so that the 808 nm background light obtains about π / 2 phase delay in this layer and works together with the Al reflection phase to form superposition in the target band, thereby improving the effective reflection intensity of the 808 nm background light in the 14th channel of the second high-speed camera.

[0054] During installation, one side of the optical reflective layer 24-2 is oriented towards the direction of light from the welding area. The optical signal from the welding area is highly reflected after reaching the optical reflective layer 24-2 and is geometrically deflected by 90° before entering the optical observation channel. Since the additional attenuation of the optical reflective layer 24-2 and the two incident side functional protective layers 24-1 and the exit side functional protective layer 24-4 is small, the X-rays are mainly transmitted through the X-ray transmission substrate layer 24-3 to achieve high transmission. Therefore, they can basically be transmitted along the original main optical path into the image receiver 7 to complete the X-ray imaging, thereby realizing X-ray transmission.

[0055] This beam splitter structure can be fabricated using thin-film processing. A Be-based X-ray transmission substrate 24-3 is used as the support substrate. First, the substrate is cleaned and surface-activated. Then, an Al-based optical reflection layer 24-2 is formed on one side of the support substrate, and an incident-side functional protective layer 24-1 made of SiO2 is formed on the Al-based optical reflection layer 24-2. Simultaneously, an exit-side functional protective layer 24-4 made of SiO2 is formed on the other side of the support substrate. The formation of each thin film layer can be achieved using vacuum deposition, sputtering deposition, evaporation deposition, ion-assisted deposition, or a combination thereof.

[0056] Considering that water vapor, salt spray, and conductive ion media in the underwater wet welding environment may penetrate along the side of the lens and cause lateral corrosion or interlayer failure between the reflective layer and the substrate layer, a sealing and anti-corrosion treatment can be further applied to the side of the beam splitter 24 to form a continuous barrier on the interlayer end face of the lens and improve long-term stability. The sealing and anti-corrosion treatment can be achieved by encapsulation, coating, potting, edge sealing, or a combination thereof.

[0057] Example 2

[0058] The synchronous monitoring system with multiple signals from the same viewing angle described in Embodiment 1 is not limited to underwater wet welding processes; it can also be applied to onshore arc welding processes. In this embodiment, no water tank is required. The workpiece to be processed is clamped and fixed on the motion actuator 2, which drives the arc welding process according to a preset trajectory or speed. The onshore arc welding process also has characteristics such as arc interference, rapid process changes, and complex information coupling. Therefore, the arc-affected area can be continuously and synchronously observed through three channels: X-ray, target band optical high-speed imaging, and spectral imaging.

[0059] In this embodiment, X-ray images are mainly used to characterize the droplet transfer behavior and the changes in the molten pool profile or interface during the arc welding process. They can be used to obtain information on processes such as droplet formation, necking, shedding, transfer, and entry into the pool. High-speed optical images are mainly used to extract visible light image features such as arc morphology, molten pool surface morphology, and weld bead profile. Spectral information is mainly used to characterize arc radiation characteristics, plasma state, and process stability.

[0060] By synchronously collecting and aligning the above three types of information, it is possible to achieve comprehensive monitoring of droplet transfer, molten pool status, arc appearance and weld formation during the onshore arc welding process from the same perspective, thereby improving the spatial consistency, synchronicity and diagnostic completeness of process monitoring.

[0061] Example 3

[0062] The simultaneous multi-signal monitoring system with the same viewing angle described in Embodiment 1 is not limited to underwater wet welding processes, but can also be applied to arc additive manufacturing processes. In this embodiment, the additive substrate / formed part is clamped on the motion actuator 2, which drives the arc additive deposition process along a preset trajectory or at a preset speed. The arc additive process is characterized by arc light interference, rapid process changes, and complex information coupling. Therefore, the additive deposition area can be continuously and synchronously observed under three channels: X-ray, target band optical high-speed imaging, and spectral imaging.

[0063] In this embodiment, X-ray images are mainly used to characterize the droplet transfer behavior and molten pool contour or interface changes during the arc additive manufacturing process; high-speed optical images are mainly used to extract visible light image features such as arc morphology, molten pool surface morphology, forming contour, layer width, layer height, and contour deviation; spectral information is mainly used to characterize arc radiation characteristics, plasma state, and process stability. By simultaneously acquiring and comprehensively analyzing the three types of information, joint monitoring of droplet transfer, molten pool state, arc appearance, and forming consistency during the arc additive manufacturing process can be achieved.

[0064] In underwater arc additive manufacturing scenarios, a water tank can be set up in the area to be observed to create an underwater working environment. In addition to characterizing the appearance and forming contour of the arc, high-speed optical images can also be used to extract the bubble contour and its behavioral characteristics such as generation, expansion, contraction and rupture. X-ray images can be further used to characterize droplet transition and interface changes under specific process conditions.

[0065] In onshore arc additive manufacturing scenarios, there is no need to set up a water tank. High-speed optical images are mainly used to characterize information such as arc morphology, molten pool surface morphology, forming contour, layer width, layer height and contour deviation; X-ray images are mainly used to characterize droplet transition behavior and molten pool contour or interface changes.

[0066] Therefore, this embodiment can be applied to underwater or onshore arc additive manufacturing processes, and can realize the simultaneous acquisition and comprehensive analysis of multi-channel information from the same perspective during the additive deposition process.

[0067] The existing technology, as disclosed in invention patent CN110539054B, is a monitoring system for arc additive manufacturing. This system mainly introduces current and temperature sensors during the arc additive manufacturing process to collect data on the welding machine's output current and weld temperature. The data is then analyzed and processed by a host computer to adjust the welding torch position and cooling time for the next layer of additive manufacturing. The key focus is on process monitoring and feedback control based on current / temperature signals. While this system can achieve online monitoring of the arc additive manufacturing status, its monitoring signals are mainly process parameters and temperature information. It cannot characterize droplet transfer, the internal processes of the molten pool, or the morphology of the external arc zone, nor does it form a combined synchronous observation structure integrating X-ray, optical images, and spectral information.

Claims

1. A multi-signal synchronous monitoring system with the same viewing angle, characterized in that, Includes an X-ray observation module, an optical monitoring module, and a controller; The X-ray observation module includes an X-ray source, a first optical path adjustment mechanism, an image receiver, and a first high-speed camera. The first high-speed camera is connected to the image receiver, which is located on one side of the first optical path adjustment mechanism. The optical monitoring module includes a background laser source, a background laser emitter, a spectrometer, a spectral acquisition probe, a second optical path adjustment mechanism, a second high-speed camera, and a bandpass filter, with the bandpass filter located in front of the second high-speed camera; the spectral acquisition probe is connected to the spectrometer for communication, and the second high-speed camera is also connected to the spectrometer for communication; the background laser emitter is connected to the background laser source. The first optical path adjustment mechanism is used to allow X-rays emitted from the X-ray source and passing through the welding area to enter the image receiver, and at the same time deflect the optical radiation generated from the welding area irradiated by the laser output head to the second optical path adjustment mechanism. The second optical path adjustment mechanism is used to divide the optical radiation into two parts: target band light and non-target band light. The target band light is sent as one path to the second high-speed camera through a bandpass filter, and the non-target band light is sent as the other path to the spectral acquisition probe. The X-ray source, image receiver, high-speed camera No. 1, and high-speed camera No. 2 are respectively connected and communicate with the controller; The No. 1 high-speed camera, the No. 2 high-speed camera, and the spectrometer synchronously perform data acquisition under the control of the controller.

2. The same-view multi-signal synchronous monitoring system according to claim 1, characterized in that, The first optical path adjustment mechanism includes a beam splitter and a beam splitter positioning device, wherein the beam splitter is connected to the beam splitter positioning device.

3. The same-view multi-signal synchronous monitoring system according to claim 2, characterized in that, The second optical path adjustment mechanism includes a dichroic mirror and a dichroic mirror positioning device, wherein the dichroic mirror is connected to the dichroic mirror positioning device.

4. The same-view multi-signal synchronous monitoring system according to claim 3, characterized in that, The beam splitter is arranged at a -45° tilt angle, and the dichroic mirror is arranged at a +45° tilt angle.

5. The same-view multi-signal synchronous monitoring system according to claim 2, characterized in that, The beam-splitting lens positioning device includes an X-axis linear module, a Y-axis linear module, a Z-axis linear module, a support plate, a lens rotation drive motor, a harmonic reducer, and a lens clamp. The Y-axis linear module is connected to the X-axis linear module, the Z-axis linear module is connected to the Y-axis linear module, and the support plate is connected to the Z-axis linear module. The lens rotation drive motor, harmonic reducer, lens clamp, and clamp support are all connected to the support plate. The lens clamp is rotatably connected to the clamp support. The output shaft of the lens rotation drive motor is connected to the input end of the harmonic reducer. The output end of the harmonic reducer is connected to one end of the lens clamp, and the rotation of the output end of the harmonic reducer drives the lens clamp to rotate. The beam-splitting lens is connected to the lens clamp.

6. The same-view multi-signal synchronous monitoring system according to claim 1, 2, 3 or 4, characterized in that, The same-view multi-signal synchronous monitoring system is configured to monitor underwater wet arc welding process, underwater wet arc additive manufacturing process, onshore arc welding process, or onshore arc additive manufacturing process.

7. The same-view multi-signal synchronous monitoring system according to claim 1, 2, 3 or 4, characterized in that, The same-view multi-signal synchronous monitoring system also includes a lead room. The X-ray source, the first optical path adjustment mechanism, the image receiver, the first high-speed camera, the second optical path adjustment mechanism, the second high-speed camera, the bandpass filter, the background laser emitter, and the spectral acquisition probe are all located inside the lead room. The controller, the spectrometer, and the background laser source are located outside the lead room. The background laser source is connected to the background laser emitter via a first optical fiber, which passes through the lead room. The spectral acquisition probe is connected to the spectrometer via a second optical fiber, which also passes through the lead room. The X-ray source, the image receiver, the first high-speed camera, and the second high-speed camera are each connected to the controller via cables, which also pass through the lead room.

8. The same-view multi-signal synchronous monitoring system according to claim 1, 2, 3 or 4, characterized in that, The same-view multi-signal synchronous monitoring system also includes a lead room. The X-ray source, the first optical path adjustment mechanism, the image receiver, the first high-speed camera, the second optical path adjustment mechanism, the background laser emitter, and the spectral acquisition probe are all located inside the lead room. The controller, the spectrometer, and the background laser source are located outside the lead room. The background laser source is connected to the background laser emitter via a first optical fiber, which passes through the lead room. The spectral acquisition probe is connected to the spectrometer via a second optical fiber, which also passes through the lead room. The X-ray source, image receiver, and high-speed camera No. 1 are respectively connected to the controller via cables, which pass through the lead room; The second high-speed camera and bandpass filter are installed outside the lead room. The lead room is equipped with an observation window that matches the second high-speed camera. The second high-speed camera is connected to the controller via a cable.

9. The same-view multi-signal synchronous monitoring system according to claim 2 or 3, characterized in that, The beam splitter includes an incident-side functional protective layer, an optical reflective layer, an X-ray transmission substrate layer, and an exit-side functional protective layer.

10. The same-view multi-signal synchronous monitoring system according to claim 9, characterized in that, The thickness of the X-ray transmission substrate is 0.25 mm, the thickness of the optical reflection layer is 100 nm, and the thickness of the emission-side functional protection layer is 80–150 nm.

11. A monitoring method using the same-view multi-signal synchronous monitoring system as described in claim 1, characterized in that, The controller analyzes and evaluates the monitored object by combining data collected from the No. 1 high-speed camera, the No. 2 high-speed camera, and the spectrometer.

12. The monitoring method according to claim 11, characterized in that, The controller evaluates one or more of the following characteristics of the monitored object based on data collected by the No. 1 high-speed camera, the No. 2 high-speed camera, and the spectrometer: droplet transfer behavior, molten pool interface changes, arc appearance, weld bead profile, forming profile, bubble behavior under specific conditions, and arc radiation characteristics.

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