Method for detecting poor welding in welding and related device

Abstract

To provide, in the field of laser machining, a method for detecting poor welding in welding and a related device.SOLUTION: An industrial personal computer (IPC) obtains an electrical signal corresponding to an infrared light signal generated by a target weld in a first period. A start moment of the first period is not earlier than a moment at which the complete target weld is formed. The IPC determines whether the target weld has poor welding according to the electrical signal corresponding to the infrared light signal, and in particular can detect whether a weld generated during sheet welding has poor welding is determined.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present application relates to the field of laser processing technology, and in particular to a method and an associated device for detecting poor penetration in welding. [Background technology]

[0002] In the computer, communication and consumer electronics (3C) sector, laser welding of metal sheets is the main method for connecting positive and negative materials in button batteries, mobile phone batteries, laptop batteries, etc. In order to ensure the quality of the welding, the results of laser welding need to be analyzed and inspected. The analysis of the welds includes the identification of welding defects.

[0003] Identifying laser welding defects in the 3C field is a big challenge. Currently, welds are often inspected only by visual inspection in the top view, which usually cannot identify the presence or absence of poor welding. If poor penetration exists in the electrode material, continuous and stable electrical contact of the battery during operation cannot be ensured, which is a big challenge. Therefore, the detection of poor penetration during laser welding of thin plates is very important. Summary of the Invention

[0004] The present application provides a method and related apparatus for detecting poor penetration in welding. The present application can be used to determine whether poor penetration exists in a weld produced during welding of thin plates.

[0005] The present application is realized using the following technical solutions.

[0006] In a first aspect, an embodiment of the present application provides a method for detecting incomplete penetration in welding, the method including: an industrial personal computer (IPC) acquires an electrical signal corresponding to an infrared light signal generated by a target weld during a first time period; a start time of the first time period is not earlier than a time when a complete target weld is formed; and the IPC determines whether incomplete penetration exists in the target weld based on the electrical signal corresponding to the infrared light signal; the target weld is formed by laser machining a sheet material.

[0007] Additionally, the IPC is configured to display an electrical signal corresponding to the infrared light signal produced by the target weld during the first period of time.

[0008] A thin material is a material having a thickness less than a preset thickness. In one example, a thin material is a material having a thickness less than 0.5 mm.

[0009] After welding of thin plate material is completed, the energy of infrared light radiated by a welded portion having a penetration defect differs from the energy of infrared light radiated by a welded portion having no penetration defect. Therefore, by detecting the infrared light signal radiated by the welded portion after welding is completed, it is possible to determine whether or not the welded portion has a penetration defect.

[0010] In combination with the first aspect, in one possible embodiment, the IPC determining whether a penetration defect exists in the target weld based on an electrical signal corresponding to the infrared light signal specifically includes determining whether a penetration defect exists in the target weld based on an electrical signal curve corresponding to the infrared light signal.

[0011] In combination with the first aspect, in one possible embodiment, the IPC determining whether there is a penetration defect in the target weld based on the electrical signal curve corresponding to the infrared light signal includes: The IPC obtains an average offset of the infrared light signal based on the electrical signal curve corresponding to the infrared light signal and a reference middle line of the infrared light signal; The IPC determines whether there is a penetration defect in the target weld based on the average offset of the infrared light signal; If the amplitude of the electrical signal curve corresponding to the infrared light signal is greater than the amplitude of the reference upper edge line of the infrared light signal and the average offset of the infrared light signal exceeds a preset offset range, it is determined that there is a penetration defect in the target weld.

[0012] The average offset of the infrared optical signal can be considered as the offset of the electrical signal corresponding to the infrared optical signal relative to a reference middle line of the infrared optical signal.

[0013] In combination with the first aspect, in one possible embodiment, the electrical signal curve corresponding to the infrared light signal includes a plurality of first points, and the reference middle line includes a plurality of second points, where the plurality of first points correspond in time to the plurality of second points. The IPC obtaining an average offset of the infrared light signal based on the electrical signal curve corresponding to the infrared light signal and the reference middle line of the infrared light signal includes the following: The IPC obtains a plurality of absolute difference values ​​by calculating an absolute value of a difference between an amplitude represented by each of the plurality of first points and an amplitude represented by a second point corresponding in time to each of the first points. The IPC obtains an average offset of the infrared light signal by summing the obtained absolute values ​​of the plurality of differences and averaging the sum result.

[0014] In combination with the first aspect, in one possible embodiment, the preset offset range is [-μ-4σ, μ+4σ], where μ is the average value of the average offsets of the electrical signals corresponding to the infrared light signals generated during the second time period by a plurality of complete welds without penetration defects obtained during historical laser processing, and σ is the standard deviation of the average offsets of the electrical signals corresponding to the infrared light signals generated during the second time period by a plurality of complete welds without penetration defects obtained during historical laser processing. The start time of the second time period is not earlier than the time when the complete welds without penetration defects are formed.

[0015] A preset offset range is determined based on the average value and standard deviation of the average offset of the electrical signal corresponding to the infrared light signal generated in a second time period by a plurality of complete welds without penetration defects obtained during historical laser processing, and the preset offset range is further used to judge whether there is a penetration defect, so that an accurate judgment result can be obtained.

[0016] In combination with the first aspect, in one possible embodiment, the IPC determining whether a penetration defect exists in the target weld based on the electrical signal curve corresponding to the infrared light signal includes: The IPC obtains an upper limit value of the infrared light signal based on the electrical signal curve corresponding to the infrared light signal and a reference upper edge line of the infrared light signal; The IPC determines whether a penetration defect exists in the target weld based on the upper limit value of the infrared light signal; If the amplitude of the electrical signal curve corresponding to the infrared light signal is greater than the amplitude of the reference upper edge line of the infrared light signal and the upper limit value of the infrared light signal is greater than an upper threshold, the IPC determines that a penetration defect exists in the target weld.

[0017] In combination with the first aspect, in one possible embodiment, the electrical signal curve corresponding to the infrared light signal includes a plurality of first points, and the reference upper edge line includes a plurality of third points, and the plurality of first points correspond in time to the plurality of third points. The IPC obtaining the upper limit value of the infrared light signal based on the electrical signal curve corresponding to the infrared light signal and the reference upper edge line of the infrared light signal includes the following: The IPC obtains a plurality of differences by calculating a difference between an amplitude represented by each of the plurality of first points and an amplitude represented by a third point corresponding in time to the first point. The IPC determines a maximum value of the plurality of differences as the upper limit value of the infrared light signal.

[0018] In combination with the first aspect, in one possible embodiment, the reference middle line of the infrared light signal includes a plurality of second points, and the reference upper edge line includes a plurality of third points, and the plurality of second points correspond in time to the plurality of third points. The method of this embodiment further includes: The IPC obtains a plurality of differences by calculating a difference between an amplitude represented by each of the plurality of third points and an amplitude represented by a second point corresponding in time to the third point; The IPC determines a maximum value of the plurality of differences as an upper threshold.

[0019] After a complete weld is formed, the energy of the infrared light generated by the weld with the penetration defect is higher than the energy of the infrared light generated by the weld without the penetration defect. Accordingly, the upper limit value of the infrared light signal generated by the weld with the penetration defect is higher than the upper limit value of the infrared light signal generated by the weld without the penetration defect. Therefore, after a complete target weld is formed, the upper limit value of the infrared light signal generated by the target weld is compared with the upper limit threshold to determine whether the energy of the infrared light generated by the target weld is higher than the energy of the infrared light generated by the weld without the penetration defect, thereby determining whether the target weld has a penetration defect. In addition, the determination result obtained by this determination method is highly accurate.

[0020] In combination with the first aspect, in one possible embodiment, the IPC determining whether a penetration defect exists in the target weld based on the electrical signal curve corresponding to the infrared light signal includes the following: The IPC obtains an upper local area of ​​the infrared light signal based on the electrical signal curve corresponding to the infrared light signal and a reference upper edge line of the infrared light signal. The upper local area of ​​the infrared light signal is an area between a portion in the electrical signal curve corresponding to the infrared light signal whose amplitude is greater than the amplitude of the reference upper edge line and the reference upper edge line. The IPC determines whether a penetration defect exists in the target weld based on the upper local area of ​​the infrared light signal. If the amplitude of the electrical signal curve corresponding to the infrared light signal is greater than the amplitude of the reference upper edge line of the infrared light signal and the upper local area of ​​the infrared light signal is greater than an upper local area threshold, the IPC determines that a penetration defect exists in the target weld.

[0021] In combination with the first aspect, in one possible embodiment, the IPC obtaining the upper local area of ​​the infrared light signal based on the electrical signal curve corresponding to the infrared light signal and the reference upper edge line of the infrared light signal includes the following: The IPC determines a first time and a second time. The first time is a start time of a first time period, and the second time is a time when the electrical signal curve corresponding to the infrared light signal intersects with the reference upper edge line. The IPC calculates a first integral area under the electrical signal curve corresponding to the infrared light signal between the first time and the second time, and calculates a second integral area under the reference upper edge line between the first time and the second time. The IPC determines a difference between the first integral area and the second integral area as the upper local area of ​​the infrared light signal.

[0022] In combination with the first aspect, in one possible embodiment, the reference upper edge line of the infrared light signal includes a plurality of third points, and the reference middle line of the infrared light signal includes a plurality of second points, and the plurality of third points correspond in time to the plurality of second points. The method of this embodiment further includes the following content: The IPC determines a start third point and an end third point from the reference upper edge line of the infrared light signal. The start third point is a third point corresponding in time to the start second point, the end third point is a third point whose represented amplitude is the same as the amplitude represented by the second point corresponding in time, and the start second point is a second point that is the first in time among the plurality of second points included in the reference middle line corresponding to the infrared light signal. The IPC calculates a third integral area under a portion between the start third point and the end third point in the reference upper edge line of the infrared light signal, and calculates a fourth integral area under a portion between the second point corresponding in time to the start third point and the second point corresponding in time to the end third point in the reference middle line of the infrared light signal. The IPC establishes half the difference between the third and fourth integrated areas as the upper local area threshold.

[0023] After a complete weld is formed, the energy of the infrared light generated by the weld with the penetration defect is higher than the energy of the infrared light generated by the weld without the penetration defect. Correspondingly, the upper local area of ​​the infrared light signal generated by the weld with the penetration defect is larger than the upper local area of ​​the infrared light signal generated by the weld without the penetration defect. Therefore, after a complete target weld is formed, the upper local area of ​​the infrared light signal generated by the target weld is compared with the upper local area threshold to determine whether the energy of the infrared light generated by the target weld is higher than the energy of the infrared light generated by the weld without the penetration defect, thereby determining whether the target weld has a penetration defect. In addition, the determination result obtained by this determination method is highly accurate.

[0024] In combination with the first aspect, in one possible embodiment, the IPC determining whether a penetration defect exists in the target weld based on the electrical signal curve corresponding to the infrared light signal includes: the IPC determining a slope of the infrared light signal based on the electrical signal curve corresponding to the infrared light signal; the IPC determining whether a penetration defect exists in the target weld based on the slope of the infrared light signal; and if the slope of the infrared light signal is greater than a slope threshold, it is determined that a penetration defect exists in the target weld.

[0025] Optionally, the electrical signal curve corresponding to the infrared light signal includes a plurality of first points. The IPC determining a slope of the infrared light signal based on the electrical signal curve corresponding to the infrared light signal includes the following: the IPC determines a start first point and an end first point from the plurality of first points. The amplitude represented by the start first point is collected at a start time of a first time period. The end first point is a first point whose represented amplitude is 0. The IPC determines a collection time of the start first point and a collection time of the end first point. The IPC calculates a first difference between the amplitude represented by the start first point and the amplitude represented by the end first point, calculates a second difference between the collection time of the start first point and the collection time of the end first point, calculates a ratio of the first difference to the second difference, and determines the ratio as a slope of the infrared light signal.

[0026] Optionally, the reference middle line of the infrared light signal includes a plurality of second points, and the plurality of first points correspond in time to the plurality of second points. The method of this embodiment further includes the following content: The IPC determines a start second point and an end second point from the plurality of second points. The start second point is a second point in the reference middle line of the infrared light signal that corresponds in time to the start first point, and the end second point is a second point in the reference middle line of the infrared light signal that corresponds in time to the end first point. The IPC calculates a third difference between the amplitude represented by the start second point and the amplitude represented by the end second point, calculates a ratio of the third difference to the second difference, and determines twice the absolute value of the ratio as the slope threshold value.

[0027] After a complete weld is formed, the energy of the infrared light generated by the weld with the penetration defect is higher than the energy of the infrared light generated by the weld without the penetration defect. Accordingly, the absolute value of the slope of the infrared light signal generated by the weld with the penetration defect is higher than the absolute value of the slope of the infrared light signal generated by the weld without the penetration defect. Therefore, after a complete target weld is formed, the absolute value of the slope of the infrared light signal generated by the target weld is compared with a slope threshold value to determine whether the energy of the infrared light generated by the target weld is higher than the energy of the infrared light generated by the weld without the penetration defect, thereby determining whether the target weld has a penetration defect. In addition, the determination result obtained by this determination method is highly accurate.

[0028] In combination with the first aspect, in one possible embodiment, the electrical signal curve corresponding to the infrared light signal includes a plurality of first points. The IPC determining whether a penetration defect exists in the target weld based on the electrical signal curve corresponding to the infrared light signal includes: the IPC calculates an average value of the amplitude of the infrared light signal based on the plurality of first points; the average value of the amplitude of the infrared light signal is an average value of the amplitudes represented by the plurality of first points; the IPC determines whether a penetration defect exists in the target weld based on the average value of the amplitude of the infrared light signal; if the average value of the amplitude of the infrared light signal is greater than an average value threshold, the IPC determines that a penetration defect exists in the target weld.

[0029] Optionally, the reference middle line of the infrared light signal includes a plurality of second points, and the average value threshold is twice the average value of the amplitudes represented by the plurality of second points.

[0030] After a complete weld is formed, the energy of the infrared light generated by the weld with the penetration defect is higher than the energy of the infrared light generated by the weld without the penetration defect. Accordingly, the average value of the amplitude of the infrared light signal generated by the weld with the penetration defect is higher than the average value of the amplitude of the infrared light signal generated by the weld without the penetration defect. Therefore, after a complete target weld is formed, the average value of the amplitude of the infrared light signal generated by the target weld is compared with the average value threshold value to determine whether the energy of the infrared light generated by the target weld is higher than the energy of the infrared light generated by the weld without the penetration defect, thereby determining whether the target weld has a penetration defect. In addition, the determination result obtained by this determination method is highly accurate.

[0031] In combination with the first aspect, in one possible embodiment, the method of the present embodiment further includes: when it is determined that there is a penetration defect in the target weld, the IPC obtains position information of the target weld; the IPC transmits the position information of the target weld to the laser welding system, and causes the laser welding system to rework the target weld based on the position information of the target weld.

[0032] If it is determined that there is a penetration defect in the target weld, the laser welding system can rework the target weld, thereby reducing the occurrence of a penetration defect in the target weld and ensuring the quality of the target weld.

[0033] In combination with the first aspect, in one possible embodiment, the method of this embodiment further includes: after a complete target weld is formed, displaying a diagram of an electrical signal curve corresponding to the infrared light signal generated by the target weld, and displaying the result of whether there is a penetration defect in the target weld.

[0034] By displaying a graph of the electrical signal curve corresponding to the infrared light signal generated by the target weld, and displaying the result of whether there is a penetration defect in the target weld, the operator can be informed of the processing quality during processing.

[0035] In a second aspect, an embodiment of the present application provides an IPC, comprising an acquisition unit, a determination unit, a transceiver unit, and a display unit, the acquisition unit, the determination unit, the transceiver unit, and the display unit configured to implement a method according to any of the first aspects.

[0036] In a third aspect, an embodiment of the present application provides an IPC comprising a processor connected to a memory, the memory configured to store a computer program, the processor executing the computer program stored in the memory to cause the IPC to perform a method according to any of the first aspects.

[0037] In a fourth aspect, an embodiment of the present application provides a laser processing control system, the laser processing control system including a laser welding system, a multi-optical sensor module, a signal processing module, and an IPC, the IPC configured to perform a method according to any of the first aspects.

[0038] In a fifth aspect, an embodiment of the present application provides a computer readable storage medium having stored thereon a computer program causing a computer to perform a method according to any of the first aspects.

[0039] In a sixth aspect, an embodiment of the present application provides a computer program product, the computer program product including a non-transitory computer readable storage medium storing a computer program, the computer operable to execute a method according to the first aspect.

[0040] As can be understood, any of the IPC described in the second aspect, the IPC described in the third aspect, the laser processing control system described in the fourth aspect, the computer readable storage medium described in the fifth aspect, or the computer program product described in the sixth aspect can be used to realize any of the methods according to the first aspect, and therefore, for advantageous effects that can be achieved by them, reference can be made to the advantageous effects of the corresponding methods, which will not be repeated here. [Brief description of the drawings]

[0041] In order to more clearly describe the embodiments of the present invention or the technical solutions in the existing technology, the following briefly introduces the drawings necessary for the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention, and those skilled in the art can obtain other drawings by these drawings without creative efforts. [Figure 1] FIG. 1 is a schematic diagram illustrating the architecture of a system for detecting poor penetration in laser welding according to an embodiment of the present application. [Diagram 2] FIG. 2 is a flowchart showing a method for detecting poor penetration in welding according to an embodiment of the present application. [Figure 3a] FIG. 3a is a time sequence diagram of detection after welding. [Figure 3b] FIG. 3b is a schematic diagram showing the welding process. [Figure 4a] FIG. 4a is a schematic diagram illustrating the calculation result of the average offset according to an embodiment of the present application. [Figure 4b] FIG. 4b is a schematic diagram showing a top local area of ​​an infrared light signal according to an embodiment of the present application. [Figure 4c] FIG. 4c is a schematic diagram showing a slope of an infrared light signal according to an embodiment of the present application. [Figure 4d] FIG. 4d is a schematic diagram showing the detection result according to an embodiment of the present application. [Diagram 5] FIG. 5 is a schematic diagram showing the structure of an industrial personal computer (IPC) according to an embodiment of the present application. [Figure 6]FIG. 6 is a schematic diagram showing the structure of another IPC according to an embodiment of the present application. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0042] Hereinafter, the technical solutions of the embodiments of the present application will be described clearly and comprehensively with reference to the drawings of the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments that a person skilled in the art can obtain without creative efforts are all within the protection scope of the present invention.

[0043] The terms used in the embodiments of this application are not intended to limit the present invention, but are used only for the purpose of describing a particular embodiment. The singular forms "a", "one" and "the" used in the embodiments, drawings and claims of this application are intended to include the plural form unless the context clearly indicates otherwise. The term "and / or" used in this specification merely describes the related relationship of related objects and indicates that there are three types of relationships. For example, A and / or B indicates three situations: only A exists, A and B exist simultaneously, and only B exists. In this specification, the sign " / " generally indicates that the related objects before and after are in an "or" relationship. The terms "first", "second", and the like used in the embodiments of this application are used only to distinguish different parts, and do not represent any order, quantity, or importance. Similarly, the terms "one" and "one" do not represent a limitation on the number, but represent the presence of at least one. In the embodiments of this application, "plurality" means two or more.

[0044] Referring to Fig. 1, it is a schematic diagram showing the architecture of a system for detecting poor penetration in laser welding according to an embodiment of the present application. As shown in Fig. 1, the system includes a laser welding system, a multi-optical sensor module 4, a signal processing module 6, and an industrial personal computer (IPC) 8.

[0045] The laser welding system includes a laser 1, an optical fiber 2, and a laser processing head 3. The laser 1 is connected to the laser processing head 3 via the optical fiber 2. A multi-optical sensor module 4 is coaxially mounted on the laser processing head 3. The multi-optical sensor module 4 is connected to a signal processing module 6 via a first signal line 5, the signal processing module 6 is connected to an IPC 8 via a second signal line 7, and the IPC 8 is connected to the laser welding system via a third signal line 12.

[0046] In this embodiment, the laser light generated by the laser 1 is transmitted to the laser processing head 3 via the optical fiber 2, and then incident on the upper plate material 10, which is a metal material waiting to be processed, via the laser processing head 3. After absorbing the laser light, the upper plate material 10 melts and solidifies to form a welded portion 9. The infrared light emitted by the welded portion 9 after welding is transmitted to the multi-optical sensor module 4 via the laser processing head 3. The multi-optical sensor module 4 can receive the infrared light emitted by the welded portion 9 after welding and convert the infrared light signal into an electrical signal. The electrical signal is transmitted to the signal processing module 6 via the first signal line 5. After the signal is processed, the processed signal is transmitted to the IPC 8 via the second signal line 7. The IPC 8 processes and identifies the received signal to determine whether or not there is a penetration defect in the welded portion 9.

[0047] Optionally, if it is determined that poor penetration exists in the welded portion 9, the position information of the welded portion 9 is determined, the position information of the welded portion 9 is transmitted to the laser welding system via the third signal line 12, and the laser welding system is controlled to perform repair welding on the welded portion 9.

[0048] In addition, in thin plate welding, when the phenomenon of poor penetration occurs, the volume of the exposed part of the molten pool of the weld does not change significantly, and the infrared light signal emitted from the molten pool of the weld during welding (i.e., during the welding process) does not change significantly, so the defect of poor penetration cannot be identified based on the infrared light signal emitted from the molten pool of the weld during welding. In other words, the molten pool of the weld does not completely penetrate the upper plate during welding, and the heat of the weld transferred to the lower plate 11 during welding is small. After welding (after the welding process is completed), the initial accumulated heat of the weld of the upper plate 10 increases significantly. Therefore, in the technical solution of the present application, whether or not there is poor penetration in the weld 9 is determined based on the infrared light signal emitted by the weld 9 after welding. In other words, the infrared light signal emitted after welding is used as the characteristic of poor penetration to determine whether or not there is a defect of poor penetration in the weld 9.

[0049] In addition, the thin plate material in this application is a material whose thickness is smaller than a preset thickness. The thin plate material is a material whose thickness is smaller than a preset thickness, and the thickness can be 0.01 mm to 0.6 mm. In one example, the thin plate material can refer to a material whose thickness is smaller than 0.5 mm. During thin plate welding, the upper plate material 10 is a thin plate material. During laser processing, a laser is first irradiated to the thin plate material, and the thin plate material and the lower welding material are melted and then welded together.

[0050] The preset thicknesses corresponding to different material sheets may be different. For example, the preset thickness corresponding to a sheet material with good heat dissipation performance is greater than the preset thickness corresponding to a sheet material with poor heat dissipation performance. For example, a copper sheet may correspond to a preset thickness in the range of 0.15mm-0.6mm, with a preferred thickness of 0.25mm. An aluminum sheet may correspond to a preset thickness in the range of 0.15mm-0.6mm, with a preferred thickness of 0.2mm. A stainless steel sheet may correspond to a preset thickness in the range of 0.1mm-0.5mm, with a preferred thickness of 0.15mm.

[0051] During laser additive machining, the topmost sheet material can be the upper cladding layer. In order to detect the penetration defects formed due to insufficient melting during additive machining, the corresponding preset thickness of the sheet material is 0.01mm-0.2mm. Similarly, the preferred preset thicknesses corresponding to the upper cladding layers of different materials are different.

[0052] Before introducing the technical solution of this application, the relevant terms of this application will be explained.

[0053] The envelope of the infrared light signal is the envelope of an electrical signal curve corresponding to the infrared light signal generated after a weld with no penetration defects or a passable weld is formed, where a passable weld has a certain difference compared to a weld with no penetration defects but is acceptable.

[0054] The infrared signal reference line is the amplitude range of the infrared signal generated after a weld with no penetration defects or a passable weld is formed, where a passable weld has a certain difference compared to a weld with no penetration defects but is acceptable.

[0055] The upper base edge-line of the infrared light signal is the upper edge line of the envelope of the infrared light signal. The upper base edge-line of the infrared light signal includes a plurality of third points, or the upper base edge-line of the infrared light signal consists of a plurality of third points. The upper base edge-line of the envelope can also be understood as the upper boundary of the amplitude range of the infrared light signal generated by welds without penetration defects or pass-through welds formed at corresponding positions on a plurality of workpieces at one welding time.

[0056] The lower base edge-line of the infrared light signal is the lower edge line of the envelope of the infrared light signal. The lower edge line of the envelope can also be understood as the lower boundary of the amplitude range of the infrared light signal generated by a weld without penetration defects or a pass weld formed at corresponding positions on multiple workpieces at one welding time.

[0057] The base midline of the infrared light signal is a midline between the reference upper edge line of the infrared light signal and the reference lower edge line of the infrared light signal. The base midline of the infrared light signal includes a plurality of second points, or the reference midline of the infrared light signal consists of a plurality of second points. Optionally, the base midline of the infrared light signal can also be obtained according to the following manner:

[0058] The amplitudes at different delay times of a plurality of welds without poor penetration or a plurality of pass welds in a plurality of historical welding processes are statistically collected, and average amplitude values ​​corresponding to the same plurality of delay times are calculated, and a reference middle line of the infrared light signal is obtained based on the average amplitude values ​​corresponding to the different delay times.

[0059] The average offset of the infrared light signal refers to the offset of the infrared light signal during welding relative to a reference middle line of the infrared light signal. It can be understood as follows: the electrical signal curve corresponding to the infrared light signal includes a plurality of first points, the reference middle line includes a plurality of second points, and the plurality of first points correspond in time to the plurality of second points. Obtaining the average offset of the infrared light signal based on the electrical signal curve corresponding to the infrared light signal and the reference middle line of the infrared light signal includes the following content: Calculating the absolute value of the difference between the amplitude represented by each of the plurality of first points and the amplitude represented by a second point corresponding in time to each of the first points, thereby obtaining the absolute values ​​of the plurality of differences; Summing up the absolute values ​​of the obtained plurality of differences and averaging the sum result, thereby obtaining the average offset of the infrared light signal.

[0060] In the application of laser processing, the infrared radiation signal corresponds to an infrared radiation signal having a wavelength in the range of 1250nm to 1700nm. The visible light radiation signal corresponds to a visible light radiation signal having a wavelength in the range of 400nm to 700nm. The laser processing reflection signal corresponds to a processing laser reflection signal during actual laser processing, for example, the processing laser has a wavelength of 915nm, 1064nm, 1080nm, etc. The wavelength of the processing laser light is related to the wavelength of the laser actually used. In some application environments, the appropriate range of the wavelength of the infrared radiation signal can be extended outside the range of 1250nm to 1700nm. In some application environments, the appropriate range of the wavelength of the visible light radiation signal can be extended outside the range of 400nm to 700nm.

[0061] The following provides a detailed description of specific embodiments of the technical solution of the present application.

[0062] Referring to Fig. 2, Fig. 2 is a flow chart illustrating a method for detecting poor penetration in welding according to an embodiment of the present application. As shown in Fig. 2, the method includes the following contents:

[0063] S201: The IPC obtains an electrical signal corresponding to an infrared light signal generated by a target weld during a first time period.

[0064] The first time period begins at a time not earlier than a time when a complete target weld is formed. The target weld is formed by laser machining the sheet material.

[0065] It should be noted that a perfect target weld in this application does not mean that there are no penetration defects in the target weld, but rather that the weld is formed after one processing run.

[0066] As shown in FIG. 3a, time t1 is the time when a welding defect detection (WDD) system starts to operate, t2 is the time when the WDD system stops operating, t3 is the time when a laser starts to emit laser light, and t4 is the time when the laser stops emitting laser light. The target weld is formed by the laser operating on the workpieces (e.g., upper plate 10 and lower plate 11) to be processed during the time period from t3 to t4. Time t5 is the time when the light intensity of the infrared light emitted by the target weld starts to become smaller than a light intensity threshold, which may be 0. The time when the complete target weld is formed is time t4. Optionally, the first time period is included in the time period from t4 to t5.

[0067] It should be understood that laser processing is a continuous process. The emission of laser light by the laser is discontinuous, during one time period the laser emits laser light, and during the next time period the laser does not emit laser light. The emission and non-emission of laser light by the laser is controlled by the laser light emission signal. As shown in Figure 3b, weld 1, weld 2, weld 3, and weld 4 are generated by the laser processing the thin plate four times. The time period from time T1 to time T2 is the time period during which the laser emits laser light, during this time period the weld 1 is generated, and the time when the complete weld 1 is formed is time T2. The time period from time T3 to time T4 is the time period during which the laser emits laser light, during this time period the weld 2 is generated, and the time when the complete weld 2 is formed is time T4. The time period from time T5 to time T6 is the time period during which the laser emits laser light, during this time period the weld 3 is generated, and the time when the complete weld 3 is formed is time T6. The time period from time T7 to time T8 is the time period during which the laser emits laser light, and the welded portion 4 is generated during this time period, with the time when the complete welded portion 4 is formed being time T8.

[0068] During welding, the infrared light signal emitted by the weld is received by the multi-optical sensor module and converted into an electrical signal, which is then transmitted to the IPC. Optionally, before the multi-optical sensor module transmits the electrical signal to the IPC, i.e., before the IPC uses the electrical signal to determine whether there is a weld insufficiency, the multi-optical sensor module processes the electrical signal, including but not limited to filtering, so as to increase the amplitude of the electrical signal and reduce noise in the electrical signal.

[0069] Optionally, the IPC may process the received electrical signal, including but not limited to filtering, before utilizing the received electrical signal to determine whether a penetration defect exists in the weld. The IPC then utilizes the processed electrical signal to determine whether a penetration defect exists in the weld.

[0070] S202: The IPC determines whether there is a penetration defect in the target weld based on the electrical signal corresponding to the infrared light signal.

[0071] In one possible embodiment, the IPC determining whether there is a penetration defect in the target weld based on the electrical signal corresponding to the infrared light signal includes: obtaining an average offset of the infrared light signal based on the electrical signal curve corresponding to the infrared light signal and a reference middle line of the infrared light signal; determining whether there is a penetration defect in the target weld based on the average offset of the infrared light signal; if the amplitude of the electrical signal curve corresponding to the infrared light signal is greater than the amplitude of the reference upper edge line of the infrared light signal and the average offset of the infrared light signal exceeds a preset offset range, it is determined that there is a penetration defect in the target weld.

[0072] The reference middle line of the infrared light signal is the middle line between the reference upper edge line of the infrared light signal and the reference lower edge line of the infrared light signal. The middle line between the reference upper edge line of the infrared light signal and the reference lower edge line of the infrared light signal is the envelope of an electrical signal corresponding to an infrared light signal generated after welding by a plurality of welds without penetration defects obtained during a plurality of historical laser processing operations. The plurality of welds without penetration defects are generated by performing laser processing on the same processing material using the same processing step.

[0073] In addition, since the electrical signal corresponding to the infrared light signal is composed of a plurality of points, the reference upper edge line and the reference lower edge line corresponding to the infrared light signal can also be considered to be composed of a plurality of points. The first point in the reference upper edge line corresponding to the infrared light signal and the first point in the reference lower edge line corresponding to the infrared light signal can be considered to be collected at the time when a complete weld was formed during multiple historical laser processing. The reference middle line corresponding to the infrared light signal can also be considered to be composed of a plurality of points. The amplitude corresponding to each point in the reference middle line corresponding to the infrared light signal is the average value of the amplitude corresponding to the point in time in the reference upper edge line corresponding to the infrared light signal and the amplitude corresponding to the point in time in the reference lower edge line corresponding to the infrared light signal.

[0074] In one possible embodiment, the electrical signal curve corresponding to the infrared light signal includes a plurality of first points, and the reference middle line includes a plurality of second points, where the plurality of first points correspond in time to the plurality of second points. The IPC obtaining an average offset of the infrared light signal based on the electrical signal curve corresponding to the infrared light signal and the reference middle line of the infrared light signal includes: the IPC obtains a plurality of absolute difference values ​​by calculating an absolute value of a difference between an amplitude represented by each of the plurality of first points and an amplitude represented by a second point corresponding in time to each of the first points; the IPC sums the obtained absolute values ​​of the differences and averages the summing result to obtain an average offset of the infrared light signal.

[0075] In one example, as shown in FIG. 4a, assume that the electrical signal curve corresponding to the infrared light signal includes eight first points, namely a1, a2, a3, a4, a5, a6, a7, and a8, and the reference middle line corresponding to the infrared light signal includes eight second points, namely b1, b2, b3, b4, b5, b6, b7, and b8. The eight first points and the eight second points correspond one by one in time. The IPC calculates the absolute value of the difference between the amplitude represented by each of the eight first points and the amplitude represented by each of the eight second points corresponding in time to the eight first points to obtain eight absolute values, and then sums up the eight absolute values ​​and averages the summed result, and the obtained result is the average offset of the infrared light signal.

[0076] After obtaining the average offset of the infrared light signal, the IPC determines whether the average offset of the infrared light signal exceeds a preset offset range. If the average offset of the infrared light signal exceeds the preset offset range, the IPC determines that a penetration defect exists in the target weld. If the average offset of the infrared light signal does not exceed the preset offset range, the IPC determines that a penetration defect does not exist in the target weld.

[0077] In another possible embodiment, the electrical signal curve corresponding to the infrared light signal includes a plurality of first points, and the reference middle line includes a plurality of second points, and the plurality of first points correspond in time to the plurality of second points. The IPC calculates a difference between an amplitude represented by each of the plurality of first points and an amplitude represented by a second point corresponding in time to each of the first points. The IPC obtains a difference greater than 0 from the calculated differences, sums the differences greater than 0, and averages the summed results to obtain an upper average offset of the infrared light signal. The IPC determines whether the upper average offset of the infrared light signal exceeds a preset offset range. If the upper average offset of the infrared light signal exceeds the preset offset range, the IPC determines that there is a penetration defect in the target weld. If the upper average offset of the infrared light signal does not exceed the preset offset range, the IPC determines that there is no penetration defect in the target weld. Note that the determination of whether the upper average offset of the infrared light signal exceeds the preset offset range specifically means the determination of whether the upper average offset of the infrared light signal is greater than an upper limit of the preset offset range. If the upper average offset of the infrared light signal is greater than the upper limit of the preset offset range, it is determined that poor penetration exists in the target weld.

[0078] Since the amount of heat radiated by a weld with poor penetration after welding is greater than the amount of heat radiated by a weld without poor penetration after welding, the difference greater than 0 can better represent the amount of heat radiated by a weld after welding. Therefore, when determining whether poor penetration exists in a weld based on the difference greater than 0, a more accurate result can be obtained.

[0079] In another possible embodiment, the electrical signal curve corresponding to the infrared light signal includes a plurality of first points, and the reference middle line includes a plurality of second points, and the plurality of first points correspond in time to the plurality of second points. The IPC calculates a difference between an amplitude represented by each of the plurality of first points and an amplitude represented by a second point corresponding in time to each of the first points. The IPC obtains a difference smaller than 0 from the calculated differences, sums the differences smaller than 0, and averages the summed results to obtain a lower average offset of the infrared light signal. The IPC determines whether the lower average offset of the infrared light signal exceeds a preset offset range. If the lower average offset of the infrared light signal exceeds the preset offset range, the IPC determines that there is a penetration defect in the target weld. If the lower average offset of the infrared light signal does not exceed the preset offset range, the IPC determines that there is no penetration defect in the target weld. Note that the determination of whether the lower average offset of the infrared light signal exceeds the preset offset range specifically means the determination of whether the lower average offset of the infrared light signal is smaller than a lower limit of the preset offset range. If the lower average offset of the infrared light signal is less than the lower limit of the preset offset range, it is determined that poor penetration exists in the target weld.

[0080] In one alternative embodiment, the preset offset range is [-μ-4σ, μ+4σ], where μ is a mean value of average offsets of electrical signals corresponding to infrared light signals generated during the second time period by a plurality of perfect welds without penetration defects obtained during historical laser processing, and σ is a standard deviation of average offsets of electrical signals corresponding to infrared light signals generated during the second time period by a plurality of perfect welds without penetration defects obtained during historical laser processing. The start time of the second time period is not earlier than the time when the perfect welds without penetration defects are formed.

[0081] The time when a complete weld is formed during the hysteretic laser processing is the time when the laser stops working during one processing. The start time of the second time period is not earlier than the time when the laser stops working. In other words, the IPC acquires electrical signals corresponding to infrared light signals emitted after welding by a plurality of welds without penetration defects formed during the hysteretic laser processing, and calculates the average value μ and standard deviation σ of the average offset of the electrical signals corresponding to infrared light signals emitted after welding by a plurality of welds without penetration defects.

[0082] Optionally, a difference between a start time of the first time slot and a time when the complete target weld is formed is greater than or equal to a difference between a start time of the second time slot and a time when the complete weld is formed during historical laser processing.

[0083] The reason for setting the difference between the start time of the first time period and the time when a complete target weld is formed larger than the difference between the start time of the second time period and the time when a complete weld is formed during hysteretic laser processing is as follows. After a complete weld is formed, the amount of heat radiated by the weld gradually decreases. After a complete weld is formed, for two welds without penetration defects, the amount of heat radiated by one weld without penetration defects and the amount of heat radiated by the other weld without penetration defects at the same time are the same, or the difference between the two is small. For one weld with penetration defects and one weld without penetration defects, the amount of heat radiated by the weld with penetration defects at the same time is higher than the amount of heat radiated by the weld without penetration defects. In addition, there are also the following situations. After a complete weld is formed, the amount of heat radiated by the weld with penetration defects at the third time is higher than the amount of heat radiated by the weld without penetration defects at the fourth time, and the third time is later than the fourth time. In other words, for a single weld A, if the amount of heat radiated by weld A at a third time is higher than the amount of heat radiated at a fourth time by a weld that does not have poor penetration, it indicates that poor penetration exists in weld A.

[0084] Therefore, when detecting whether or not there is a penetration defect in the target weld, an electrical signal corresponding to the infrared light signal generated by the target weld in a first time period is obtained, and the electrical signal corresponding to the infrared light signal generated in the first time period is compared with the expectation and variance of the electrical signals corresponding to the infrared light signals generated in a second time period by a plurality of welds formed during historical laser processing that do not have a penetration defect, thereby determining whether or not there is a penetration defect in the target weld, thereby improving the accuracy of detecting the penetration defect.

[0085] In addition, since the amount of heat radiated by the weld gradually decreases after a complete weld is formed, the amplitude of the acquired electrical signal corresponding to the infrared light signal generated by the target weld in the first time period is smaller than the amplitude of the electrical signal corresponding to the infrared light signal generated by the target weld before the first time period. Therefore, the IPC has a smaller amplitude to process and a relatively faster processing speed, which can improve the efficiency of poor penetration detection.

[0086] In one possible embodiment, the IPC can also determine whether there is a penetration gap in the target weld based on the following method.

[0087] In Method 1, the IPC obtains an upper limit value of the infrared light signal based on the electrical signal curve corresponding to the infrared light signal and a reference upper edge line of the infrared light signal. The IPC determines whether there is a penetration defect in the target weld based on the upper limit value of the infrared light signal. If the amplitude of the electrical signal curve corresponding to the infrared light signal is greater than the amplitude of the reference upper edge line of the infrared light signal and the upper limit value of the infrared light signal is greater than an upper limit-threshold, the IPC determines there is a penetration defect in the target weld.

[0088] The reference upper edge line of the infrared light signal is the upper edge line of the envelope obtained based on the electrical signal corresponding to the infrared light signal generated after a complete weld without any penetration defects is formed during historical welding.

[0089] In one example, the upper limit of the infrared light signal is obtained as follows.

[0090] The electrical signal curve corresponding to the infrared light signal includes a plurality of first points, or the electrical signal curve corresponding to the infrared light signal consists of a plurality of first points. The reference upper edge line of the infrared light signal includes a plurality of third points, or the reference upper edge line of the infrared light signal consists of a plurality of third points. The plurality of first points correspond in time to the plurality of third points. The IPC calculates a difference between an amplitude represented by each of the plurality of first points and an amplitude represented by a third point corresponding in time to the first point. In this way, the IPC obtains a plurality of differences, and determines the maximum of the plurality of differences as the upper limit value of the infrared light signal.

[0091] In one example, the upper threshold is obtained as follows:

[0092] The reference middle line of the infrared light signal includes a plurality of second points or consists of a plurality of second points. The plurality of second points correspond in time to a plurality of third points. The IPC calculates a difference between an amplitude represented by each of the plurality of third points and an amplitude represented by a second point corresponding in time to the third point. In this manner, the IPC obtains a plurality of differences and determines a maximum value of the plurality of differences as an upper threshold of the infrared light signal.

[0093] After a complete weld is formed, the energy of the infrared light generated by the weld with the penetration defect is higher than the energy of the infrared light generated by the weld without the penetration defect. Correspondingly, the upper limit value of the infrared light signal generated by the weld with the penetration defect is higher than the upper limit value of the infrared light signal generated by the weld without the penetration defect. Thus, after a complete target weld is formed, the upper limit value of the infrared light signal generated by the target weld is compared with an upper limit threshold value to determine whether the energy of the infrared light generated by the target weld is higher than the energy of the infrared light generated by the weld without the penetration defect, thereby determining whether the target weld has a penetration defect.

[0094] In the second method, the IPC obtains an upper local-area of ​​the infrared light signal based on the electrical signal curve corresponding to the infrared light signal and the reference upper edge line of the infrared light signal. The upper local-area of ​​the infrared light signal is the area of ​​a region between a part in the electrical signal curve corresponding to the infrared light signal whose amplitude is greater than the amplitude of the reference upper edge line of the infrared light signal and the reference upper edge line of the infrared light signal. The IPC determines whether there is a penetration defect in the target weld based on the upper local-area of ​​the infrared light signal. If the amplitude of the electrical signal curve corresponding to the infrared light signal is greater than the amplitude of the reference upper edge line of the infrared light signal and the upper local-area of ​​the infrared light signal is greater than an upper local-area threshold, the IPC determines there is a penetration defect in the target weld.

[0095] In one example, the top local area of ​​the infrared light signal is obtained as follows.

[0096] A first time and a second time are determined. The first time is a start time of a first time period, and the second time is a time when an electrical signal curve corresponding to the infrared light signal intersects with a reference upper edge line of the infrared light signal. The electrical signal curve corresponding to the infrared light signal includes a plurality of first points, or the electrical signal curve corresponding to the infrared light signal consists of a plurality of first points. The reference upper edge line of the infrared light signal includes a plurality of third points, or the reference upper edge line of the infrared light signal consists of a plurality of third points. The plurality of first points correspond in time to the plurality of third points. The second time is a time when an amplitude represented by the first points is the same as an amplitude represented by a third point corresponding in time to the first points. The IPC calculates a first integral area under the electrical signal curve corresponding to the infrared light signal between the first time and the second time, and calculates a second integral area under the reference upper edge line of the infrared light signal between the first time and the second time. As shown in FIG. 4b, the IPC determines the difference between the first and second integrated areas as the top local area of ​​the infrared light signal.

[0097] In one example, the upper local area threshold is obtained as follows:

[0098] The reference upper edge line of the infrared light signal includes a plurality of third points, or the reference upper edge line of the infrared light signal consists of a plurality of third points. The reference middle line of the infrared light signal includes a plurality of second points, or the reference middle line of the infrared light signal consists of a plurality of second points. The IPC determines a start third point and an end third point from the reference upper edge line of the infrared light signal. The start third point is a third point corresponding in time to the start second point. The end third point is a third point whose represented amplitude is the same as the represented amplitude by the second point corresponding in time. The start second point is a first second point in the reference middle line of the infrared light signal. The IPC calculates a third integral area under a portion between the start third point and the end third point in the reference upper edge line of the infrared light signal, and calculates a fourth integral area under a portion between the second point corresponding in time to the start third point and the second point corresponding in time to the end third point in the reference middle line of the infrared light signal. The IPC establishes half the difference between the third and fourth integrated areas as the upper local area threshold.

[0099] After a complete weld is formed, the energy of the infrared light generated by the weld with the penetration defect is higher than the energy of the infrared light generated by the weld without the penetration defect. Correspondingly, the upper local area of ​​the infrared light signal generated by the weld with the penetration defect is larger than the upper local area of ​​the infrared light signal generated by the weld without the penetration defect. Thus, after a complete target weld is formed, the upper local area of ​​the infrared light signal generated by the target weld is compared to an upper local area threshold to determine whether the energy of the infrared light generated by the target weld is higher than the energy of the infrared light generated by the weld without the penetration defect, thereby determining whether the target weld has a penetration defect.

[0100] In Method 3, the IPC determines a slope of the infrared light signal based on the electrical signal curve corresponding to the infrared light signal. Determine whether there is a penetration defect in the target weld based on the slope of the infrared light signal. If the slope of the infrared light signal is greater than a slope threshold, the IPC determines there is a penetration defect in the target weld.

[0101] Furthermore, if the amplitude of the electrical signal curve corresponding to the infrared light signal is greater than the amplitude of the reference upper edge line of the infrared light signal and the slope of the infrared light signal is greater than a slope threshold, the IPC determines that there is a poor penetration in the target weld.

[0102] In one example, the slope of the infrared light signal is obtained as follows:

[0103] The IPC determines a start first point and an end first point from the electrical signal curve corresponding to the infrared optical signal. The amplitude represented by the start first point is collected at the start time of a first time period. The end first point is the first point whose represented amplitude is zero. As shown in FIG. 4c, the IPC determines the collection time of the start first point and the collection time of the end first point. The IPC calculates a first difference between the amplitude represented by the start first point and the amplitude represented by the end first point, calculates a second difference between the collection time of the start first point and the collection time of the end first point, and calculates a ratio of the first difference to the second difference. The ratio is the slope of the infrared optical signal.

[0104] In addition, the amplitude being 0 means that the difference between the temperature of the target welding portion and the temperature of the working environment is smaller than a preset temperature value. For example, the amplitude being 0 means that the temperature of the target welding portion and the temperature of the working environment are the same.

[0105] In one example, the slope threshold is obtained as follows:

[0106] The IPC determines a second start point and a second end point from the reference middle line of the infrared light signal. The second start point is a second point in the reference middle line of the infrared light signal that corresponds in time to the first start point. The second end point is a second point in the reference middle line of the infrared light signal that corresponds in time to the first end point. The IPC calculates a third difference between the amplitude represented by the second start point and the amplitude represented by the second end point, and the IPC calculates a ratio of the third difference to the second difference and determines two times the absolute value of the ratio as a slope threshold.

[0107] After a complete weld is formed, the energy of the infrared light generated by the weld with the penetration defect is higher than the energy of the infrared light generated by the weld without the penetration defect. Correspondingly, the absolute value of the slope of the infrared light signal generated by the weld with the penetration defect is higher than the absolute value of the slope of the infrared light signal generated by the weld without the penetration defect. Thus, after a complete target weld is formed, the absolute value of the slope of the infrared light signal generated by the target weld is compared with a slope threshold value to determine whether the energy of the infrared light generated by the target weld is higher than the energy of the infrared light generated by the weld without the penetration defect, thereby determining whether the target weld has a penetration defect.

[0108] In Method 4, the IPC calculates an average value of the amplitude of the infrared light signal based on the electrical signal curve corresponding to the infrared light signal, and determines whether there is a penetration defect in the target weld based on the average value of the amplitude of the infrared light signal. If the average value of the amplitude of the infrared light signal is greater than the average value threshold, the IPC determines that there is a penetration defect in the target weld.

[0109] Furthermore, if the amplitude of the electrical signal curve corresponding to the infrared light signal is greater than the amplitude of the reference upper edge line of the infrared light signal, and the average value of the amplitude of the infrared light signal is greater than the average value threshold, the IPC determines that there is poor penetration in the target weld.

[0110] In one example, the average threshold is determined as follows:

[0111] The IPC calculates the average value of the amplitudes represented by a plurality of second points included in the reference middle line of the infrared light signal, and determines twice the average value as the average value threshold.

[0112] After a complete weld is formed, the energy of the infrared light generated by the weld with the poor penetration is higher than the energy of the infrared light generated by the weld without the poor penetration. Correspondingly, the average value of the amplitude of the infrared light signal generated by the weld with the poor penetration is higher than the average value of the amplitude of the infrared light signal generated by the weld without the poor penetration. Thus, after a complete target weld is formed, the average value of the amplitude of the infrared light signal generated by the target weld is compared to an average value threshold value to determine whether the energy of the infrared light generated by the target weld is higher than the energy of the infrared light generated by the weld without the poor penetration, thereby determining whether the target weld has poor penetration.

[0113] In one possible embodiment, the method of the present embodiment further includes: the IPC displays a diagram of an electrical signal curve corresponding to the infrared light signal generated by the target weld after the complete target weld is formed, and displays the result of whether there is a penetration defect in the target weld.

[0114] Fig. 4d is a schematic diagram showing a detection result according to an embodiment of the present application. As shown in Fig. 4d, the IPC displays an electrical signal corresponding to the infrared light signal generated by the target weld after welding and a reference middle line of the infrared light signal, and indicates whether there is a penetration defect in the target weld.

[0115] By displaying the diagram of the electrical signal curve corresponding to the infrared light signal generated by the target weld after welding, and the result of whether there is a penetration defect in the target weld, the operator can observe the result of the laser processing, i.e., whether there is a penetration defect in the weld after laser processing, in real time.

[0116] S203: If it is determined that there is a penetration defect in the target weld, the IPC obtains the position information of the target weld.

[0117] The location information of the target weld can be represented by a serial number of the target weld. Note that since laser processing is a continuous process and the resulting weld is also continuous, the location of the weld may be represented by a serial number of the weld.

[0118] After obtaining the position information of the target weld, the IPC transmits the position information of the target weld to the laser welding system, so that the laser welding system remachines the target weld based on the position information of the target weld to remove the incomplete weld.

[0119] In one possible embodiment, when determining that there is a penetration defect in the target weld, the IPC obtains from the laser welding system the distance between the laser processing head and the processing material (i.e., the upper plate material 10) when the target weld is generated during processing. The distance may be called the processing distance. The IPC compares the processing distance with a preset distance. If the processing distance is different from the preset distance, the change in the processing distance changes the amount of defocus, indicating that there is a penetration defect in the target weld, thus resulting in the occurrence of the penetration defect. The IPC sends instruction information to the laser welding system, instructing the laser welding system to adjust the distance between the laser processing head and the plate material. The adjusted distance is the same as the preset distance. The preset distance is the distance between the laser processing head and the processing material that is manually set so that there is no penetration defect in the weld generated during processing.

[0120] Optionally, if the processing distance is the same as the preset distance, it indicates that the cause of the poor penetration is not the defocus amount. The IPC acquires the temperature of the lens in the laser processing head during processing. In addition, if the lens is dirty, the temperature of the lens rises, so whether the lens is dirty is determined by determining whether the temperature of the lens is higher than the temperature of an uncontaminated lens. If it is determined that the temperature of the lens is higher than the temperature of an uncontaminated lens, the IPC sends warning information to the operator to warn him that the lens in the laser processing head is dirty.

[0121] Optionally, if the processing distance is equal to the preset distance, it indicates that the cause of the poor penetration is not the defocus amount, and the IPC sends instruction information to the laser welding system to instruct the laser welding system to increase the laser power.

[0122] After the above adjustment is completed, the IPC sends the position information of the target weld to the laser welding system, so that the laser welding system reworks the target weld to remove the incomplete penetration according to the position information of the target weld.

[0123] As can be seen from the above, in the solution of the present application, during laser processing, the multi-optical sensor module obtains the infrared light signal generated by the weld after welding. Then, based on the infrared light signal, it is determined whether there is a penetration defect in the weld. Compared with the existing technology, the solution of the present application has the characteristics of non-contact and real-time, and the solution of the present application can be used to perform 100% inspection during industrial production. In addition, the solution of the present application can be used to detect the defect of penetration defect. After obtaining the position information of the target weld, the position information of the target weld is transmitted to the laser welding system, so that the laser welding system can remachine the target weld and automatically perform repair welding.

[0124] Referring to Fig. 5, Fig. 5 is a schematic diagram showing the structure of an industrial personal computer (IPC) according to an embodiment of the present application. As shown in Fig. 5, the IPC 500 includes an acquisition unit 501 and a determination unit 502. The acquisition unit 501 is configured to acquire an electrical signal corresponding to an infrared light signal generated by a target weld in a first time period, where the start time of the first time period is not earlier than the time when a complete target weld is formed, and the target weld is formed by laser processing a thin plate material. The determination unit 502 is configured to determine whether there is a penetration defect in the target weld based on the electrical signal corresponding to the infrared light signal.

[0125] In one possible embodiment, the determining unit 502 is configured to determine whether there is a penetration defect in the target weld based on the electrical signal curve corresponding to the infrared light signal.

[0126] In one possible embodiment, the determining unit 502 is configured to obtain an average offset of the infrared light signal according to the electrical signal curve corresponding to the infrared light signal and the reference middle line of the infrared light signal, and determine whether there is a penetration defect in the target weld according to the average offset of the infrared light signal. If the amplitude of the electrical signal curve corresponding to the infrared light signal is greater than the amplitude of the reference upper edge line of the infrared light signal and the average offset of the infrared light signal exceeds a preset offset range, it is determined that there is a penetration defect in the target weld.

[0127] In one possible embodiment, the electrical signal curve corresponding to the infrared light signal includes a plurality of first points, the reference middle line includes a plurality of second points, and the plurality of first points correspond in time to the plurality of second points. For obtaining an average offset of the infrared light signal based on the electrical signal curve corresponding to the infrared light signal and the reference middle line of the infrared light signal, the determining unit 502 is configured to: calculate an absolute value of a difference between an amplitude represented by each of the plurality of first points and an amplitude represented by a second point corresponding in time to each of the first points to obtain the absolute values ​​of the plurality of differences, and sum the absolute values ​​of the obtained differences to average the summing result to obtain the average offset of the infrared light signal.

[0128] In one possible embodiment, the preset offset range is [-μ-4σ, μ+4σ], where μ is the average value of the average offsets of the electrical signals corresponding to the infrared light signals generated during the second time period by a plurality of complete welds without penetration defects obtained during historical laser processing, and σ is the standard deviation of the average offsets of the electrical signals corresponding to the infrared light signals generated during the second time period by a plurality of complete welds without penetration defects obtained during historical laser processing. The start time of the second time period is not earlier than the time when the complete welds without penetration defects are formed.

[0129] In one possible embodiment, the determining unit 502 is specifically configured to obtain an upper limit value of the infrared light signal according to the electrical signal curve corresponding to the infrared light signal and a reference upper edge line of the infrared light signal, and determine whether there is a penetration defect in the target weld according to the upper limit value of the infrared light signal. If the amplitude of the electrical signal curve corresponding to the infrared light signal is greater than the amplitude of the reference upper edge line of the infrared light signal and the upper limit value of the infrared light signal is greater than an upper threshold, it is determined that there is a penetration defect in the target weld.

[0130] In one possible embodiment, the electrical signal curve corresponding to the infrared light signal includes a plurality of first points, the reference upper edge line includes a plurality of third points, and the plurality of first points correspond in time to the plurality of third points. Regarding obtaining the upper limit value of the infrared light signal based on the electrical signal curve corresponding to the infrared light signal and the reference upper edge line of the infrared light signal, the determining unit 502 is specifically configured to calculate a difference between an amplitude represented by each of the plurality of first points and an amplitude represented by a third point corresponding in time to the first point, thereby obtaining a plurality of differences, and determining a maximum value of the plurality of differences as the upper limit value of the infrared light signal.

[0131] In one possible embodiment, the reference middle line of the infrared light signal includes a plurality of second points, the reference upper edge line includes a plurality of third points, and the plurality of second points correspond in time to the plurality of third points. The determining unit 502 is further configured to obtain a plurality of differences by calculating a difference between an amplitude represented by each of the plurality of third points and an amplitude represented by a second point corresponding in time to the third point, and determine a maximum value of the plurality of differences as the upper threshold value.

[0132] In one possible embodiment, the determining unit 502 is configured to obtain an upper local area of ​​the infrared light signal based on the electrical signal curve corresponding to the infrared light signal and the reference upper edge line of the infrared light signal, and the upper local area of ​​the infrared light signal is an area between a part in the electrical signal curve corresponding to the infrared light signal whose amplitude is greater than the amplitude of the reference upper edge line and the reference upper edge line. The determining unit 502 is configured to determine whether there is a penetration defect in the target weld based on the upper local area of ​​the infrared light signal. If the amplitude of the electrical signal curve corresponding to the infrared light signal is greater than the amplitude of the reference upper edge line of the infrared light signal and the upper local area of ​​the infrared light signal is greater than an upper local area threshold, it is determined that there is a penetration defect in the target weld.

[0133] In one possible embodiment, obtaining an upper local area of ​​the infrared light signal based on an electrical signal curve corresponding to the infrared light signal and a reference upper edge line of the infrared light signal includes: The determining unit 502 is configured to determine a first time and a second time, where the first time is a start time of a first time period and the second time is a time when an electrical signal curve corresponding to the infrared light signal intersects with a reference upper edge line. The determining unit 502 is configured to calculate a first integral area under the electrical signal curve corresponding to the infrared light signal between the first time and the second time, calculate a second integral area under the reference upper edge line between the first time and the second time, and determine a difference between the first integral area and the second integral area as the upper local area of ​​the infrared light signal.

[0134] In one possible embodiment, the reference upper edge line of the infrared light signal includes a plurality of third points, and the reference middle line of the infrared light signal includes a plurality of second points, and the plurality of third points correspond in time to the plurality of second points. The determining unit 502 is further configured to determine a starting third point and an ending third point from the reference upper edge line of the infrared light signal, where the starting third point is a third point corresponding in time to the starting second point, the ending third point is a third point whose represented amplitude is the same as that represented by the time-corresponding second point, and the starting second point is a first second point in the reference middle line of the infrared light signal. The determination unit 502 is further configured to calculate a third integral area under a portion between a starting third point and an ending third point in a reference upper edge line of the infrared light signal, calculate a fourth integral area under a portion between a second point corresponding in time to the starting third point and a second point corresponding in time to the ending third point in a reference middle line of the infrared light signal, and determine half the difference between the third integral area and the fourth integral area as an upper local area threshold.

[0135] In one possible embodiment, the determining unit 502 is configured to determine a slope of the infrared light signal based on the electrical signal curve corresponding to the infrared light signal, and determine whether there is a penetration defect in the target weld based on the slope of the infrared light signal. If the slope of the infrared light signal is greater than a slope threshold, it is determined that there is a penetration defect in the target weld.

[0136] Optionally, the electrical signal curve corresponding to the infrared light signal includes a plurality of first points. Regarding determining a slope of the infrared light signal based on the electrical signal curve corresponding to the infrared light signal, the determining unit 502 is configured to determine a start first point and an end first point from the plurality of first points, where the amplitude represented by the start first point is collected at a start time of a first time period, and the end first point is a first point whose represented amplitude is 0. The determining unit 502 is configured to determine a collection time of the start first point and a collection time of the end first point, calculate a first difference between the amplitude represented by the start first point and the amplitude represented by the end first point, calculate a second difference between the collection time of the start first point and the collection time of the end first point, calculate a ratio of the first difference to the second difference, and determine the ratio as a slope of the infrared light signal.

[0137] Optionally, the reference middle line of the infrared light signal includes a plurality of second points, and the plurality of first points correspond in time to the plurality of second points. The determining unit 502 is further configured to determine a start second point and an end second point from the plurality of second points, where the start second point is a second point in the reference middle line of the infrared light signal that corresponds in time to the start first point, and the end second point is a second point in the reference middle line of the infrared light signal that corresponds in time to the end first point. The determining unit 502 is further configured to calculate a third difference between the amplitude represented by the start second point and the amplitude represented by the end second point, calculate a ratio of the third difference to the second difference, and determine twice the absolute value of the ratio as the slope threshold value.

[0138] In combination with the first aspect, in one possible embodiment, the electrical signal curve corresponding to the infrared light signal includes a plurality of first points. The determining unit 502 is configured to calculate an average value of the amplitude of the infrared light signal based on the plurality of first points, and the average value of the amplitude of the infrared light signal is an average value of the amplitudes represented by the plurality of first points. The determining unit 502 is configured to determine whether there is a penetration defect in the target weld based on the average value of the amplitude of the infrared light signal. If the average value of the amplitude of the infrared light signal is greater than the average value threshold, the determining unit 502 determines that there is a penetration defect in the target weld.

[0139] Optionally, the reference middle line of the infrared light signal includes a plurality of second points, and the average value threshold is twice the average value of the amplitudes represented by the plurality of second points.

[0140] In one possible embodiment, the acquisition unit 501 is configured to acquire position information of the target weld when it is determined that a penetration defect exists in the target weld.

[0141] IPC 500 further includes a transceiver unit 503. Transceiver unit 503 is configured to transmit the target weld position information to the laser welding system and cause the laser welding system to rework the target weld based on the target weld position information.

[0142] In one possible embodiment, the IPC 500 further comprises a display unit 504. The display unit 504 is configured to display a diagram of an electrical signal curve corresponding to the infrared light signal generated by the target weld after a complete target weld is formed, and display the result of whether there is a penetration defect in the target weld.

[0143] It should be noted that each of the above units (acquisition unit 501, determination unit 502, transceiver unit 503, and display unit 504) is used to perform the relevant steps of the above method. For example, the acquisition unit 501 is used to perform the relevant content of S201, the determination unit 502 is used to perform the relevant content of S202, and the transceiver unit 503 and display unit 504 are used to perform the relevant content of S203. Each or all of the units or modules in the IPC 500 may be integrated into one or several other units or modules, or some (several) of the units or modules may be further divided into several smaller units or modules in terms of function. Thereby, the same operation can be realized without affecting the realization of the technical effect of the embodiment of the present invention. The above units or modules are divided based on logic functions. In practical application, the function of one unit (or module) can be realized by several units (or modules), or the function of several units (or modules) can be realized by one unit (or module).

[0144] Based on the above description of the method and device embodiments, reference is made to Fig. 6, which is a schematic diagram illustrating the structure of another IPC 600 according to an embodiment of the present application. The IPC 600 shown in Fig. 6 (IPC 600 may specifically be a computer device) includes a memory 601, a processor 602, a communication interface 603, and a bus 604. The memory 601, the processor 602, and the communication interface 603 are communicatively connected to each other via the bus 604.

[0145] The memory 601 can be a read only memory (ROM), a static storage device, a dynamic storage device, or a random access memory (RAM).

[0146] The memory 601 can store a program. When the program stored in the memory 601 is executed by the processor 602, the processor 602 and the communication interface 603 are used to execute various steps of the method for detecting poor penetration in welding according to an embodiment of the present application.

[0147] The processor 602 may be a general-purpose central processing unit (CPU), a microprocessor, an application specific integrated circuit (ASIC), a graphics processing unit (GPU), or one or more integrated circuits. The processor 602 is used to execute associated programs to realize the functions performed by the units in the IPC 600 according to the embodiments of the present application, or to perform the method for detecting poor penetration in welding according to the method embodiments of the present application.

[0148] The processor 602 can be an integrated circuit chip having signal processing capabilities. In the implementation process, each step of the method for detecting poor penetration in welding of the present application can be completed by an integrated logic circuit in the form of hardware or an instruction in the form of software in the processor 602. The processor 602 can be a general-purpose processor, a digital signal processor (DSP), an ASIC, a field programmable gate array (FPGA) or other programmable logic device, a discrete gate or transistor logic device, a discrete hardware component. The processor 602 can realize or execute various methods, steps and logic block diagrams disclosed in the embodiments of the present application. The general-purpose processor can be a microprocessor or any ordinary processor, etc. The steps of the methods disclosed in the embodiments of the present application can be directly performed and completed by a hardware decoding processor, or can be performed and completed by a combination of hardware and software modules in the decoding processor. The software module can be located in a storage medium well known in the art, such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory, or an electrically erasable programmable memory, a register, etc. The storage medium is located in the memory 601. The processor 602 reads information in the memory 601 and, together with its hardware, realizes the functions performed by the units in the IPC 500 according to the embodiments of the present application, or performs the method for detecting poor penetration in welding according to the method embodiments of the present application.

[0149] The communication interface 603 may be, but is not limited to, a transceiver device such as a walkie-talkie. The communication interface 603 allows communication between the IPC 600 and other devices or communication networks. For example, data may be obtained via the communication interface 603.

[0150] The bus 604 may include a connection path used to transfer information between each component of the IPC 600 (eg, the memory 601, the processor 602, the communication interface 603).

[0151] It should be noted that the IPC 600 shown in FIG. 6 only illustrates a memory, a processor, and a communication interface, but in a specific embodiment, a person skilled in the art should understand that the IPC 600 also includes other components necessary for normal operation. At the same time, a person skilled in the art should understand that the IPC 600 may also include other hardware components to achieve other additional functions according to specific needs. In addition, a person skilled in the art should understand that the IPC 600 may include only the components necessary to implement the embodiment of the present application, and does not need to include all of the components shown in FIG. 6.

[0152] An embodiment of the present application further provides a chip, the chip including a processor and a data interface, the processor reading instructions stored in the memory through the data interface to execute the method for detecting poor penetration in a weld.

[0153] Optionally, in one embodiment, the chip may further include a memory having instructions stored therein, and a processor adapted to execute the instructions stored in the memory, and when the instructions are executed, the processor adapted to execute a method for detecting poor penetration in a weld.

[0154] An embodiment of the present application further provides a computer-readable storage medium having instructions stored thereon that, when executed by a computer or processor, cause the computer or processor to perform one or more steps of any of the methods described above.

[0155] An embodiment of the present application further provides a computer program product comprising instructions which, when executed on a computer or processor, cause the computer or processor to perform one or more steps of any of the methods described above.

[0156] It can be appreciated by those skilled in the art that the functions described in conjunction with the various exemplary logical block diagrams, modules, and algorithm steps described in the disclosure herein can be implemented by hardware, software, firmware, or any combination thereof. When implemented by software, the functions described in the various exemplary logical block diagrams, modules, and steps can be stored on or transmitted via a computer-readable medium as one or more instructions or codes and executed by a hardware-based processing unit. Computer-readable media includes computer-readable storage media. Computer-readable media corresponds to tangible media, examples of which include data storage media or communication media including any medium that facilitates the transfer of a computer program from one place to another (e.g., based on a communication protocol). Thus, computer-readable media may generally correspond to (1) a non-transitory tangible computer-readable storage medium, or (2) a communication medium such as a signal or carrier. Data storage media may be any available medium that can be accessed by one or more computers or one or more processors to retrieve instructions, codes, and / or data structures for implementing the techniques described in this application. The computer program product may include a computer-readable medium.

[0157] By way of non-limiting example, such computer readable storage media may include RAM, ROM, electrically erasable programmable read only memory (EEPROM), compact disk ROM (CD-ROM) or other optical disk storage, magnetic disk storage or other magnetic storage, flash memory, or any other medium that stores desired program code in the form of instructions or data structures and that can be accessed by a computer. Also, any connection may be properly referred to as a computer readable medium. By way of example, if instructions are transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, microwave, etc., the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, microwave, etc., are included in the definition of media. However, computer readable storage media and data storage media do not include connections, carriers, signals, or other transitory media, and indeed cover non-transitory tangible storage media. As used herein, magnetic disks and optical disks include compact disks (CDs), laser disks, optical disks, digital versatile discs (DVDs), and Blu-ray disks, where magnetic disks typically reproduce data magnetically and optical disks reproduce data optically using a laser. Combinations of the above should also be included within the scope of computer-readable media.

[0158] The instructions may be executed by one or more processors, such as, for example, one or more DSPs, general-purpose microprocessors, ASICs, FPGAs, or other equivalent integrated circuits or discrete logic circuits. Thus, the term "processor" as used herein may refer to any one of the above structures, or any other structure suitable for implementing the techniques described herein. Furthermore, in some aspects, the functionality described in the various exemplary logic block diagrams, modules, and steps described herein may be provided in dedicated hardware and / or software modules configured for use in encoding and decoding, or may be incorporated into an integrated encoder-decoder. Additionally, the techniques may be fully implemented in one or more circuits or logic elements.

[0159] The techniques of the present application may be implemented in a variety of apparatuses or devices, including a wireless mobile phone, an integrated circuit (IC), or a set of ICs (e.g., a chipset). This application emphasizes the functionality of a device configured to perform the disclosed techniques using various components, modules, or units, not necessarily realized by different hardware units. Indeed, as described above, the various units may be combined with appropriate software and / or firmware in a hardware unit of a codec, or may be provided in an interoperable hardware unit (including one or more processors as described above).

[0160] Those skilled in the art may clearly understand that for convenience and conciseness of explanation, the specific operation processes of the above systems, devices, and units may refer to the specific descriptions of the processes of the corresponding steps in the above method embodiments, and will not be repeated in this specification.

[0161] In the description of this application, unless otherwise specified, the symbol " / " indicates that the related objects before and after are in an "or" relationship. For example, A / B indicates A or B, and A and B may be singular or plural. In the description of this application, unless otherwise specified, "plurality" means two or more. "At least one of the following" or a similar expression means any combination of these items, including any combination of single items or multiple items. For example, at least one of a, b, or c can indicate a, b, c, a and b, a and c, b and c, or a, b, and c. Each of a, b, and c may be singular or plural. In order to facilitate a clear description of the technical solutions of the embodiments of this application, the embodiments of this application use terms such as "first" and "second" to distinguish between identical or similar things having the same basic functions and roles. Those skilled in the art will understand that terms such as "first" and "second" do not limit the number or execution order, and terms such as "first" and "second" do not necessarily limit different. In addition, in the embodiments of the present application, terms such as "exemplary" or "for example" mean "as an example, illustration, explanation." In the embodiments of the present application, any embodiment or design described as "for example" or "exemplary" should not be construed as being superior to other embodiments or design. To be precise, the use of terms such as "exemplary" or "for example" is intended to present related concepts in a concrete manner for ease of understanding.

[0162] It should be understood that in some embodiments of the present application, the disclosed system, device, and method may be realized in other forms. For example, the division of units is merely a division of logical functions, and may have other division forms when actually realized. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not implemented. The couplings, direct couplings, and communication connections between the shown or discussed mutually may be indirect couplings or communication connections by some interfaces, devices, or units, and may be electrical, mechanical, or other forms.

[0163] The units described as separate components may or may not be physically separated. The components shown as units may or may not be physical units, i.e., they may be located in one place or may be arranged in multiple network units. Some or all of the units may be selected according to actual needs to achieve the objective of the technical solution of this embodiment.

[0164] All or part of the above embodiments can be realized by software, hardware, firmware, or any combination thereof. When realized by software, all or part of the above embodiments can be realized in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed by a computer, all or part of the processes or functions described in the embodiments of the present application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in or transmitted through a computer-readable storage medium. The computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center by wire (e.g., coaxial cable, fiber optic, DSL, etc.) or wireless (e.g., infrared, radio, microwave, etc.). The computer-readable storage medium can be any available medium that can be accessed by a computer, or can be a data storage device in which one or more available media are integrated, such as a server, a data center, etc. The available medium may be a ROM, a RAM, a magnetic medium (e.g., a floppy disk, a hard disk, a magnetic tape, a magnetic disk), an optical medium (e.g., a DVD), or a semiconductor medium (e.g., a solid state disk (SSD)).

[0165] The above is only a specific embodiment of the embodiment of the present application, and the protection scope of the embodiment of the present application is not limited thereto. Any modifications or replacements within the technical scope disclosed in the embodiment of the present application should be included in the protection scope of the embodiment of the present application. Therefore, the protection scope of the embodiment of the present application should be determined by the protection scope of the claims.

[0166] The above-mentioned device embodiments are merely illustrative, and the units and modules described as separate components may or may not be physically separated. In addition, some or all of the units and modules can be selected according to actual needs to achieve the objective of the technical solution of the present embodiment. Those skilled in the art can understand and implement it without any creative efforts.

[0167] The above are only specific embodiments of the present application, and those skilled in the art may make some improvements and modifications without departing from the principles of the present application, which should also fall within the scope of protection of the present application.

Claims

1. A method for detecting poor penetration in welding, comprising: acquiring an electrical signal corresponding to an infrared light signal generated by a target weld during a first time period, the first time period having a start time no earlier than a time when a complete target weld is formed, the target weld being formed by laser machining a sheet material; determining whether a penetration defect exists in the target weld based on an electrical signal corresponding to the infrared light signal; Including, A method for detecting poor penetration in welding, comprising:

2. determining whether a penetration defect exists in the target weld based on an electrical signal corresponding to the infrared light signal; determining whether there is a penetration defect in the target weld based on an electrical signal curve corresponding to the infrared light signal; 2. The method for detecting poor penetration in welding according to claim 1.

3. determining whether there is a penetration defect in the target weld based on the electrical signal curve corresponding to the infrared light signal; Obtaining an upper limit value of the infrared light signal based on an electrical signal curve corresponding to the infrared light signal and a reference upper edge line of the infrared light signal; determining whether a penetration defect exists in the target weld based on an upper limit value of the infrared light signal; When the amplitude of the electrical signal curve corresponding to the infrared light signal is greater than the amplitude of the reference upper edge line of the infrared light signal, and the upper limit value of the infrared light signal is greater than an upper threshold value, it is determined that there is a poor penetration in the target weld.

3. The method for detecting poor penetration in welding according to claim 2.

4. the electrical signal curve corresponding to the infrared light signal includes a plurality of first points, the reference upper edge line includes a plurality of third points, the plurality of first points correspond in time to the plurality of third points, and obtaining an upper limit value of the infrared light signal based on the electrical signal curve corresponding to the infrared light signal and the reference upper edge line of the infrared light signal; calculating a difference between an amplitude represented by each of the plurality of first points and an amplitude represented by a third point corresponding in time to the first points to obtain a plurality of differences; determining a maximum value of the plurality of differences as an upper limit value of the infrared light signal; Including, 4. The method for detecting poor penetration in welding according to claim 3.

5. a reference middle line of the infrared light signal including a plurality of second points, and a reference upper edge line of the infrared light signal including a plurality of third points, the plurality of second points corresponding in time to the plurality of third points, and the method for detecting poor penetration in welding includes: calculating a difference between an amplitude represented by each of the plurality of third points and an amplitude represented by a second point corresponding in time to the third point to obtain a plurality of differences; determining a maximum value of the plurality of differences as the upper threshold value; Further comprising:

4. The method for detecting poor penetration in welding according to claim 3.

6. determining whether there is a penetration defect in the target weld based on the electrical signal curve corresponding to the infrared light signal; Obtaining an upper local area of ​​the infrared light signal based on an electrical signal curve corresponding to the infrared light signal and a reference upper edge line of the infrared light signal, the upper local area of ​​the infrared light signal being an area of ​​a region between a portion of the electrical signal curve corresponding to the infrared light signal, the portion having an amplitude greater than the amplitude of the reference upper edge line, and the reference upper edge line; determining whether a poor penetration exists in the target weld based on a top local area of ​​the infrared light signal; When the amplitude of the electrical signal curve corresponding to the infrared light signal is greater than the amplitude of the reference upper edge line of the infrared light signal, and the upper local area of ​​the infrared light signal is greater than an upper local area threshold, it is determined that there is a poor penetration in the target weld.

3. The method for detecting poor penetration in welding according to claim 2.

7. Obtaining an upper local area of ​​the infrared light signal based on an electrical signal curve corresponding to the infrared light signal and a reference upper edge line of the infrared light signal, determining a first time and a second time, the first time being a start time of the first time period and the second time being a time at which an electrical signal curve corresponding to the infrared light signal intersects with the reference upper edge line; calculating a first integrated area under a curve of an electrical signal corresponding to the infrared light signal between the first time and the second time, and calculating a second integrated area under the reference upper edge line between the first time and the second time; determining a difference between the first integrated area and the second integrated area as a top local area of ​​the infrared light signal.

7. The method for detecting poor penetration in welding according to claim 6.

8. a reference upper edge line of the infrared light signal includes a plurality of third points, a reference middle line of the infrared light signal includes a plurality of second points, the plurality of third points correspond in time to the plurality of second points, and the method for detecting poor penetration in welding includes: determining a third start point and a third end point from a reference upper edge line of the infrared light signal, the third start point being a third point corresponding in time to the second start point, the third end point being a third point whose represented amplitude is the same as the represented amplitude by the second point corresponding in time, and the second start point being a first second point within a reference middle line of the infrared light signal; calculating a third integrated area under a portion of a reference upper edge line of the infrared light signal between the third starting point and the third ending point, and calculating a fourth integrated area under a portion of a reference middle line of the infrared light signal between a second point corresponding in time to the third starting point and a second point corresponding in time to the third ending point; determining half the difference between the third integrated area and the fourth integrated area as the upper local area threshold; Further comprising:

7. The method for detecting poor penetration in welding according to claim 6.

9. determining whether there is a penetration defect in the target weld based on the electrical signal curve corresponding to the infrared light signal; determining a slope of the infrared light signal based on an electrical signal curve corresponding to the infrared light signal; determining whether a poor penetration exists in the target weld based on a slope of the infrared light signal; If the slope of the infrared light signal is greater than a slope threshold, it is determined that a poor penetration exists in the target weld.

3. The method for detecting poor penetration in welding according to claim 2.

10. The electrical signal curve corresponding to the infrared light signal includes a plurality of first points, and determining a slope of the infrared light signal based on the electrical signal curve corresponding to the infrared light signal includes: determining a start first point and an end first point from the plurality of first points, where the amplitude represented by the start first point is collected at the start time, and the end first point is a first point where the represented amplitude is zero; determining a collection time of the first starting point and a collection time of the first ending point; calculating a first difference between an amplitude represented by the starting first point and an amplitude represented by the ending first point, calculating a second difference between a collection time of the starting first point and a collection time of the ending first point, and calculating a ratio of the first difference to the second difference, the ratio being a slope of the infrared light signal. The method for detecting poor penetration in welding according to claim 9.

11. a reference middle line of the infrared light signal including a plurality of second points, the plurality of first points corresponding in time to the plurality of second points, and the method for detecting poor penetration in welding includes: determining a second start point and a second end point from the plurality of second points, the second start point being a second point in time corresponding to the first start point within a reference middle line of the infrared light signal, and the second end point being a second point in time corresponding to the first end point within a reference middle line of the infrared light signal; calculating a third difference between the amplitude represented by the starting second point and the amplitude represented by the ending second point, calculating a ratio of the third difference to the second difference, and determining twice the absolute value of the ratio as the slope threshold; Further comprising: The method for detecting poor penetration in welding according to claim 10.

12. The electrical signal curve corresponding to the infrared light signal includes a plurality of first points, and determining whether there is a penetration defect in the target weld based on the electrical signal curve corresponding to the infrared light signal is Calculating an average value of an amplitude of the infrared light signal based on the plurality of first points, the average value of the amplitude of the infrared light signal being an average value of amplitudes represented by the plurality of first points; determining whether a poor penetration exists in the target weld based on an average value of the amplitude of the infrared light signal; If the average value of the amplitude of the infrared light signal is greater than an average value threshold, it is determined that there is a poor penetration in the target weld.

3. The method for detecting poor penetration in welding according to claim 2.

13. The reference middle line of the infrared light signal includes a plurality of second points, and the method for detecting poor penetration in welding includes: calculating an average value of the amplitudes represented by the second plurality of points and determining twice the average value as the average value threshold. The method for detecting poor penetration in welding according to claim 12.

14. determining whether there is a penetration defect in the target weld based on the electrical signal curve corresponding to the infrared light signal; Obtaining an average offset of the infrared light signal based on an electrical signal curve corresponding to the infrared light signal and a reference middle line of the infrared light signal; determining whether a poor penetration exists in the target weld based on the average offset of the infrared light signal; When the amplitude of the electrical signal curve corresponding to the infrared light signal is greater than the amplitude of the reference upper edge line of the infrared light signal, and the average offset of the infrared light signal exceeds a preset offset range, it is determined that there is a poor penetration in the target weld.

3. The method for detecting poor penetration in welding according to claim 2.

15. the electrical signal curve corresponding to the infrared light signal includes a plurality of first points, the reference middle line includes a plurality of second points, the plurality of first points correspond in time to the plurality of second points, and obtaining an average offset of the infrared light signal based on the electrical signal curve corresponding to the infrared light signal and the reference middle line of the infrared light signal; calculating an absolute value of a difference between an amplitude represented by each of the plurality of first points and an amplitude represented by a second point corresponding in time to each of the plurality of first points to obtain a plurality of absolute difference values; summing the absolute values ​​of the obtained differences and averaging the summation result to obtain an average offset of the infrared light signal; Including, The method for detecting poor penetration in welding according to claim 14.

16. the preset offset range is [-μ-4σ, μ+4σ], μ is an average value of average offsets of electrical signals corresponding to infrared light signals generated during a second time period by a plurality of complete welds without penetration defects obtained during historical laser processing, σ is a standard deviation of average offsets of electrical signals corresponding to infrared light signals generated during a second time period by a plurality of complete welds without penetration defects obtained during historical laser processing, and a start time of the second time period is not earlier than a time when the complete welds without penetration defects are formed; The method for detecting poor penetration in welding according to claim 14.

17. The method for detecting poor penetration in welding comprises: When it is determined that the target weld portion has a penetration defect, acquiring position information of the target weld portion; transmitting position information of the target weld to a laser welding system, and causing the laser welding system to remachine the target weld based on the position information of the target weld; Further comprising:

2. The method for detecting poor penetration in welding according to claim 1.

18. The method for detecting poor penetration in welding comprises: After the target weld is completely formed, displaying a graph of an electrical signal curve corresponding to the infrared light signal generated by the target weld, and displaying a result of whether there is a penetration defect in the target weld.

2. The method for detecting poor penetration in welding according to claim 1.

19. The thickness of the sheet material is 0.01 mm to 0.6 mm; 2. The method for detecting poor penetration in welding according to claim 1.

20. An industrial personal computer (IPC) comprising an acquisition unit, a display unit, and a determination unit, the acquisition unit is configured to acquire an electrical signal corresponding to an infrared light signal generated by a target weld during a first time period, the start time of the first time period being no earlier than a time when a complete target weld is formed, the target weld being formed by laser machining a sheet material; the display unit is configured to display an electrical signal corresponding to an infrared light signal generated by the target weld during a first time period; The determining unit is configured to determine whether a penetration defect exists in the target weld based on an electrical signal corresponding to the infrared light signal.

1. An industrial personal computer comprising:

21. 1. An industrial personal computer (IPC), comprising: A processor is provided. The processor is connected to a memory, and the memory is configured to store a computer program, and the processor executes the computer program stored in the memory to cause the IPC to execute the method for detecting poor penetration in welding according to any one of claims 1 to 19.

1. An industrial personal computer comprising:

22. 1. A laser processing control system, comprising: The present invention includes a laser welding system, a multi-optical sensor module, a signal processing module, and an industrial personal computer (IPC), The IPC is configured to perform the method for detecting poor penetration in welding according to any one of claims 1 to 19. A laser processing control system comprising:

23. 1. A computer-readable storage medium, comprising: A computer program is stored in the computer-readable storage medium, and the method for detecting poor penetration in welding according to any one of claims 1 to 19 is performed by executing the computer program by a processor. A computer-readable storage medium comprising:

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