Spot welding system and related method

Abstract

The application provides a spot welding system and a related method, which comprises the following steps: determining a first attribute parameter of an upper automobile workpiece and a second attribute parameter of a lower automobile workpiece corresponding to a spot welding position; determining a first working parameter of a pre-pressing stage, a second working parameter of a welding stage and a third working parameter of a pressure maintaining stage according to the first attribute parameter, the second attribute parameter and the spot welding position; performing an electrode pressing operation according to the spot welding position and the first working parameter, and recording a first pressure parameter in the electrode pressing operation; adjusting the second working parameter according to the first pressure parameter to obtain a target second working parameter, and determining a target third working parameter according to the target second working parameter and the third working parameter; and determining a fourth working parameter of a pressure releasing stage according to the target third working parameter, so that the spot welding quality stability and the spot welding effect can be ensured.

Description

Technical Field

[0001] This application relates to the field of intelligent manufacturing technology, specifically to a spot welding system and related methods. Background Technology

[0002] In automotive manufacturing, spot welding is widely used in the welding and assembly of major structural components such as the roof, doors, side panels, and floor. Typically, a car contains thousands of resistance spot welds. Inconsistent welding quality during spot welding directly impacts vehicle safety and manufacturing efficiency. Therefore, ensuring the stability and effectiveness of spot welding during automotive manufacturing is a crucial issue that needs to be addressed. Summary of the Invention

[0003] This application provides a spot welding system and related methods that can ensure the stability of spot welding quality and the effectiveness of spot welding during automobile processing.

[0004] In a first aspect, embodiments of this application provide a spot welding method, the method comprising: The upper-layer automotive workpiece is photographed to obtain a first image, and the weld point position is determined based on the first image; the upper-layer automotive workpiece is fixed by a first fixing module, and the lower-layer automotive workpiece is fixed by a second fixing module. Determine the first attribute parameter of the upper automotive workpiece and the second attribute parameter of the lower automotive workpiece corresponding to the weld point position; The first working parameters for the pre-pressing stage, the second working parameters for the welding stage, and the third working parameters for the pressure holding stage are determined based on the first attribute parameter, the second attribute parameter, and the weld point position. Perform electrode pressurization operation according to the solder joint position and the first working parameter, record the first pressure parameter during the electrode pressurization operation, adjust the second working parameter according to the first pressure parameter to obtain the target second working parameter, and determine the target third working parameter according to the target second working parameter and the third working parameter. Welding is performed at the weld joint location according to the target second working parameters, pressure holding is performed according to the target third working parameters, a fourth working parameter for the pressure relief stage is determined based on the target third working parameters, and a pressure relief operation is performed at the weld joint location according to the fourth working parameters.

[0005] Secondly, embodiments of this application provide a spot welding system, which includes: a vision module, a first fixing module, a second fixing module, a spot welding module, and a control module, wherein... The first fixing module is used to fix the upper automotive workpiece; The second fixing module is used to fix the lower automotive workpiece; The vision module is used to photograph the upper automotive workpiece to obtain a first image, and to determine the location of the weld point based on the first image. The control module is used to determine the first attribute parameters of the upper automotive workpiece and the second attribute parameters of the lower automotive workpiece corresponding to the weld point position; and to determine the first working parameters of the pre-pressing stage, the second working parameters of the welding stage, and the third working parameters of the pressure holding stage based on the first attribute parameters, the second attribute parameters, and the weld point position. The control module is further configured to: execute an electrode pressurization operation based on the weld point position and the first working parameters using the vision module and the spot welding module; record a first pressure parameter during the electrode pressurization operation; adjust the second working parameters based on the first pressure parameter to obtain a target second working parameter; determine a target third working parameter based on the target second working parameter and the third working parameter; execute a welding operation at the weld point position according to the target second working parameter using the spot welding module; execute a pressure holding operation at the weld point position according to the target third working parameter; determine a fourth working parameter for the pressure release stage based on the target third working parameter; and execute a pressure release operation at the weld point position according to the fourth working parameter using the spot welding module.

[0006] Implementing the embodiments of this application has the following beneficial effects: As can be seen, the spot welding system and related methods described in the embodiments of this application, firstly, automatically identify the weld point position through a vision module, and adaptively determine the initial working parameters for each stage of pre-pressing, welding, and holding pressure by combining the material, thickness, and other attribute parameters of the upper and lower automotive workpieces. This avoids weld point misalignment and parameter mismatch caused by manual parameter setting deviations, thereby improving the weld point positioning accuracy and welding parameter adaptability from the source. Secondly, pressure parameters are collected in real time during electrode pressurization, and the working parameters of the welding stage are dynamically adjusted based on these pressure parameters. This can compensate for the actual working condition differences caused by workpiece assembly gaps and contact resistance fluctuations, further ensuring the heat input stability of the welding process and reducing the generation of welding defects. Third, based on the adjusted working parameters of the welding stage and the initial working parameters of the holding pressure stage, the working parameters of the holding pressure stage are derived in conjunction with these parameters. Then, the working parameters of the depressurization stage are determined accordingly. This achieves the correlation optimization of working parameters in each stage of the entire welding process, avoiding the problem of mismatched weld nugget stress caused by independent setting of working parameters in each stage. This effectively reduces the risk of defects such as shrinkage cavities and cracks. Through the dynamic perception and correlation adjustment of working parameters in multiple stages, intelligent closed-loop control of spot welding of automotive parts is achieved. This not only improves the consistency of welding quality and yield, but also reduces manual debugging intervention. It helps to ensure the stability of spot welding quality and the spot welding effect in the automotive processing process, especially in the scenario of batch spot welding of automotive parts. Attached Figure Description

[0007] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0008] Figure 1 This is a schematic diagram of the structure of a spot welding system provided in an embodiment of this application; Figure 2 This is a schematic diagram of another spot welding system provided in the embodiments of this application; Figure 3 This is a schematic diagram illustrating a spot welding scenario provided in an embodiment of this application; Figure 4 This is a schematic flowchart of a spot welding method provided in an embodiment of this application; Figure 5 This is a schematic flowchart of another spot welding method provided in the embodiments of this application; Figure 6 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Detailed Implementation

[0009] The terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that comprises a series of steps or units is not limited to the listed steps or units, but in one possible example includes steps or units not listed, or in one possible example includes other steps or units inherent to these processes, methods, products, or apparatuses.

[0010] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0011] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present application.

[0012] In this embodiment, the robot may include robots used in automobile processing, such as intelligent robotic arms, intelligent machine tools, humanoid robots, automobile processing robots, etc., and is not limited thereto. Electronic devices may include the robot.

[0013] In this embodiment, spot welding can be understood as a resistance solid-state welding technology. It can apply pressure to overlapping metal plates and pass a large current through electrodes (welding electrodes). The metal is melted by the heat generated by the resistance of the contact surface, and then cooled and solidified under pressure to form a weld point, thus achieving a firm connection between the plates. Spot welding technology is widely used in automobile processing.

[0014] Please see Figure 1 , Figure 1 This is a schematic diagram of a spot welding system provided in an embodiment of this application. The spot welding system includes: a vision module, a first fixing module, a second fixing module, and a spot welding module.

[0015] The spot welding system can be configured in automotive processing environments, such as automotive production lines, automotive factories, automotive repair shops, and automotive modification sites. The vision module, the first fixing module, the second fixing module, and the spot welding module can be electrically connected and / or communicatively connected.

[0016] The vision module may include at least one of the following: laser sensor, camera, radar sensor, ultrasonic sensor, etc., without limitation. The vision module may also include a robot. The vision module may include a 3D vision system.

[0017] The spot welding module may include electrodes, namely welding electrodes.

[0018] The first fixing module is used to fix the upper automotive workpiece. It can work with the vision module to locate the weld points and provide a support reference for the upward pressure of the spot welding electrode. The first fixing module can include: pneumatic / electric grippers, vacuum adsorption fixtures, floating positioning fixtures, etc. Specifically, taking the pneumatic / electric gripper as an example, it can use a cylinder to drive the gripping arm to clamp the edge of the workpiece to adapt to automotive workpieces of different sizes; taking the vacuum adsorption fixture as an example, it can use negative pressure to adsorb the surface of the upper automotive workpiece to avoid damaging the appearance of the workpiece; taking the floating positioning fixture as an example, it can float slightly with the electrode pressure to compensate for the assembly gap of the workpiece.

[0019] In practice, the first fixed module can be installed on a movable mechanism (such as a robotic arm or a slide table), and its position can be adjusted in conjunction with the vision module to adapt to the welding requirements of different weld points.

[0020] The second fixing module is used to fix the lower automotive workpiece, serving as a reference support platform for welding to ensure that the lower automotive workpiece does not shift or deform during the welding process. The second fixing module may include: a worktable positioning fixture, an electromagnetic chuck, a hydraulic clamping mold, etc. Specifically, taking the worktable positioning fixture as an example, it can fix the position of the lower automotive workpiece using positioning pins and stops, combined with hydraulic clamping; taking the electromagnetic chuck as an example, it can magnetically attract the lower automotive workpiece, providing stable clamping force without mechanical damage; taking the hydraulic clamping mold as an example, it can provide large clamping force to prevent deformation of thick plates or high-strength steel workpieces.

[0021] In practice, the second fixing module can be fixed on the welding worktable or machine tool, and its position is stable, so as to serve as a reference for the welding coordinate system.

[0022] In practice, the second fixing module first fixes the lower automotive workpiece to establish a welding reference coordinate system, and then the first fixing module clamps the upper automotive workpiece. During the welding process, the relative positions of the upper and lower automotive workpieces can be calibrated by the vision module to determine the final weld point position. During welding, the welding electrode of the spot welding module can apply pressure from top to bottom. The first fixing module can provide reverse support, and the second fixing module can provide bottom support. Together, they ensure stable transmission of welding pressure.

[0023] Among them, spot welding scenarios in the automotive manufacturing process can include at least one of the following: inner door panel and outer door panel, roof panel and side pillar, inner hood panel and outer hood panel, floor longitudinal beam and reinforcing plate, door reinforcing rib and inner door panel, battery housing upper cover and lower battery housing, bumper reinforcing plate and front longitudinal beam of the vehicle body, seat frame plate and connecting bracket, etc. In specific implementation, when the inner door panel is the upper automotive workpiece, the outer door panel can be the lower automotive workpiece.

[0024] In specific implementations, for example, taking the welding of thin plate covering parts as an example, the first fixing module can be a vacuum adsorption fixture, and the second fixing module can be an electromagnetic chuck; taking the welding of thick plate structural parts as an example, the first fixing module can be a vacuum adsorption fixture, and the second fixing module can be a hydraulic clamping mold; taking the welding of irregular-shaped parts as an example, the first fixing module can be a floating positioning fixture, and the second fixing module can be a customized positioning pin fixture.

[0025] The spot welding module may include a spot welding robot, which is mainly used to perform welding functions. For example, the spot welding robot can select appropriate welding materials and equipment, and can select welding rods, welding wires, shielding gases, etc. according to the material type (e.g., low carbon steel, aluminum alloy, etc.) and thickness to ensure welding quality. The welding module may include a robot.

[0026] Among them, such as Figure 2 As shown, the spot welding system may also include a control module, a temperature detection module, an environmental sensor, etc. The control module, temperature detection module, environmental sensor, vision module, first fixing module, second fixing module, and spot welding module are communicatively connected and / or electrically connected. The control module may include a robot, processor, control platform, etc., which is equivalent to the "brain" of the "spot welding system". It can be used to instruct the vision module and spot welding module to complete the corresponding spot welding functions, adjust the fixing effect of the first fixing module and the second fixing module, and collect the data fed back by the temperature detection module and environmental sensor, and perform the next operation based on the data.

[0027] The temperature detection module can be used to acquire the temperature of the melt nugget. For example, it can acquire the temperature at a preset sampling frequency, which can be pre-set or set by the system default. The temperature detection module may include an infrared thermal imager or a miniature temperature sensor. For example, a miniature temperature sensor can be placed on the contact surface between the electrode and the workpiece to measure the temperature of the melt nugget.

[0028] Among them, environmental sensors can collect environmental parameters, which may include at least one of the following: temperature, humidity, magnetic field interference intensity, atmospheric pressure, etc.

[0029] In specific implementation, such as Figure 3 As shown, in a specific implementation, during the spot welding process, the electrodes of the spot welding module can include an upper electrode and a lower electrode. The upper electrode corresponds to the upper layer of the automotive workpiece, and the lower electrode corresponds to the lower layer of the automotive workpiece. The upper electrode and the lower electrode work together spot weld the weld point, and a weld nugget can be formed during the spot welding process.

[0030] based on Figure 1 or Figure 2 The spot welding system shown can perform the following functions: The first fixing module is used to fix the upper automotive workpiece; The second fixing module is used to fix the lower automotive workpiece; The vision module is used to photograph the upper automotive workpiece to obtain a first image, and to determine the location of the weld point based on the first image. The control module is used to determine the first attribute parameters of the upper automotive workpiece and the second attribute parameters of the lower automotive workpiece corresponding to the weld point position; and to determine the first working parameters of the pre-pressing stage, the second working parameters of the welding stage, and the third working parameters of the pressure holding stage based on the first attribute parameters, the second attribute parameters, and the weld point position. The control module is further configured to: execute an electrode pressurization operation based on the weld point position and the first working parameters using the vision module and the spot welding module; record a first pressure parameter during the electrode pressurization operation; adjust the second working parameters based on the first pressure parameter to obtain a target second working parameter; determine a target third working parameter based on the target second working parameter and the third working parameter; execute a welding operation at the weld point position according to the target second working parameter using the spot welding module; execute a pressure holding operation at the weld point position according to the target third working parameter; determine a fourth working parameter for the pressure release stage based on the target third working parameter; and execute a pressure release operation at the weld point position according to the fourth working parameter using the spot welding module.

[0031] Optionally, the first pressure parameter includes the pressure change curve during the pre-compression stage; regarding the adjustment of the second operating parameter based on the first pressure parameter to obtain the target second operating parameter, the control module is specifically used for: Obtain the standard pressure change curve for the pre-compression stage; the standard pressure change curve includes a first part of the standard pressure change curve for the initial contact period, a second part of the standard pressure change curve for the pressure rise period, and a standard pressure change straight line for the stable holding period; the standard pressure change straight line corresponds to the reference pressure. Determine the target pressure fluctuation parameters based on the pressure change curve; The pre-pressure deviation value is determined based on the standard pressure change line and the pressure change curve. The target second operating parameter is determined based on the target pressure fluctuation parameter, the preset pressure deviation value, and the second operating parameter.

[0032] Please see Figure 4 , Figure 4 This is a schematic flowchart of a spot welding method provided in an embodiment of this application, applied to... Figure 1 or Figure 2 The spot welding system shown includes the following spot welding method: S401. Take a picture of the upper-layer automotive workpiece to obtain a first image, and determine the position of the weld point based on the first image; the upper-layer automotive workpiece is fixed by a first fixing module, and the lower-layer automotive workpiece is fixed by a second fixing module.

[0033] The fixed parameters of the first fixed module can be preset or set by the system default. The fixed parameters of the second fixed module can also be preset or set by the system default.

[0034] In specific implementation, two automotive workpieces to be welded can be stacked and fixed according to design requirements using a first fixing module and a second fixing module. This ensures precise positioning and no displacement of the workpieces, while also guaranteeing that the distance between the weld point and the workpiece edge, as well as the spacing between adjacent weld points, meets process requirements. The second fixing module first fixes the lower automotive workpiece to establish a welding reference coordinate system. Specifically, the vision module first identifies the lower automotive workpiece to obtain its relevant second attribute information. This second attribute information can include at least one of the following: the name of the lower automotive workpiece, its dimensions, the welding purpose, its second material parameters (e.g., material density, material type), thickness parameters (e.g., plate thickness), yield strength, tensile strength, electrical conductivity, thermal conductivity, melting point, coefficient of thermal expansion, surface roughness, coating type, coating thickness, surface cleanliness, surface hardness, etc. Since the spot welding system may have previously spot welded lower automotive workpieces corresponding to this second attribute information in batches, the corresponding fixing parameters (e.g., fixing position, fixing force, etc.) can be obtained, and the lower automotive workpiece can be fixed based on these fixing parameters.

[0035] Next, the first fixing module can clamp the upper-layer automotive workpiece, and the vision module can identify the upper-layer automotive workpiece to obtain its relevant first attribute information. The first attribute information may include at least one of the following: the name of the upper-layer automotive workpiece, the size of the upper-layer automotive workpiece, the welding purpose of the upper-layer automotive workpiece, the first material parameters of the upper-layer automotive workpiece (e.g., material density, material type), thickness parameters (e.g., plate thickness), yield strength, tensile strength, electrical conductivity, thermal conductivity, melting point, coefficient of thermal expansion, surface roughness, coating type, coating thickness, surface cleanliness, surface hardness, etc. Since the spot welding system may have previously spot welded upper-layer automotive workpieces corresponding to this first attribute information in batches, the corresponding fixing parameters (e.g., fixing position, fixing force, etc.) can be obtained, and the upper-layer automotive workpiece can be fixed based on these fixing parameters. During the specific welding process, the relative position of the upper and lower automotive workpieces can also be calibrated by the vision module to determine the final weld point position.

[0036] Specifically, the vision module then takes a picture of the upper-layer automotive workpiece to obtain a first image. Based on the first image, the location of the weld points is determined. For example, the weld points of the upper-layer automotive workpiece in the first image can be identified and located. Since both the upper-layer and lower-layer automotive workpieces are known, as well as their placement and fixation, their corresponding welding positions can be pre-marked (for example, using big data analysis). The weld point locations can be marked in the first image. Especially in the batch processing of automotive workpieces, the required weld point locations can be accurately located based on specific processing scenarios and processing requirements.

[0037] S402. Determine the first attribute parameter of the upper automotive workpiece and the second attribute parameter of the lower automotive workpiece corresponding to the weld point position.

[0038] The first attribute parameter may include the first material parameter and thickness parameter of the upper automotive workpiece; the second attribute parameter may include the second material parameter of the lower automotive workpiece.

[0039] In a specific implementation, a pre-stored mapping relationship between a preset position and the attribute parameters of the upper-level automotive workpiece can be used. Based on this mapping relationship, the first attribute parameter of the upper-level automotive workpiece corresponding to the weld point position can be determined. Alternatively, an image of the upper-level automotive workpiece at the weld point position can be obtained, and the first attribute parameter of the upper-level automotive workpiece can be identified based on the image.

[0040] The system can pre-store a mapping relationship between preset positions and attribute parameters of the lower-level automotive workpiece. Based on this mapping relationship, the second attribute parameter of the lower-level automotive workpiece corresponding to the weld point position can be determined. Alternatively, an image of the lower-level automotive workpiece corresponding to the weld point position can be obtained, and the second attribute parameter of the lower-level automotive workpiece can be identified based on the image.

[0041] S403. Determine the first working parameters for the pre-pressure stage, the second working parameters for the welding stage, and the third working parameters for the pressure holding stage based on the first attribute parameter, the second attribute parameter, and the weld point position.

[0042] The spot welding process can be divided into four stages: pre-pressurization stage, welding stage, pressure holding stage, and pressure release stage. In the pre-pressurization stage, pressure is applied using electrodes; in the welding stage, a large current is output, and the contact surface of the plates at the weld point generates heat due to resistance, forming a weld nugget; in the pressure holding stage, pressure and current are maintained to ensure that the weld nugget fully solidifies; in the pressure release stage, the power is cut off and the electrodes are raised to complete the single-point welding.

[0043] The first operating parameters of the spot welding module during the pre-pressurization stage may include: standard pressure change linearity, pressurization time, etc. The second operating parameters during the welding stage may include: pressurization pressure, operating current, time, etc. The third operating parameters during the pressure holding stage may include: pressurization pressure, operating current, time, etc. The fourth operating parameter during the depressurization stage may include: time, etc.

[0044] The standard pressure change curve can include a first part of the standard pressure change curve during the initial contact period, a second part of the standard pressure change curve during the pressure rise period, and a straight line of standard pressure change during the stable holding period; the straight line of standard pressure change corresponds to the reference pressure. The pressure change characteristics during the initial contact period can be: from the start of electrode contact to the automotive workpiece pressure rapidly rising to approximately 30%~50% of the reference pressure, with a duration of 10~50 ms. The pressure change characteristics during the pressure rise period can be: the pressure continuously rising to the reference pressure, with a duration of 20~100 ms. The pressure change characteristics during the stable holding period can be: the pressure remaining within a certain range (plus or minus 5%) of the reference pressure, with a duration of 50~300 ms.

[0045] In practice, since the first attribute parameter, the second attribute parameter, and the weld point position are fixed, big data technology can be used to obtain the first working parameters of the pre-pressure stage, the second working parameters of the welding stage, and the third working parameters of the pressure holding stage of the spot welding module.

[0046] In practice, the pre-pressure stage can last from 0.05 to 0.2 seconds. During this stage, the electrodes are closed, and pressure is applied to the automotive workpiece to ensure close contact between the workpiece and the electrodes. Power is only supplied after the pressure reaches the set value (reference pressure) to prevent incomplete welds. The welding stage can last from 0.1 to 0.5 seconds. It primarily utilizes a large current passing through the contact surface of the automotive workpiece to generate hot Joules, melting the metal to form a weld nugget. The pressure is maintained at the set value during this stage. The holding pressure stage typically lasts 10% to 30% of the welding stage. It mainly involves current switching, i.e., stopping welding, while the electrodes continue to maintain the pressure corresponding to the set value, allowing the weld nugget to cool and solidify under pressure. The depressurization stage can be set according to the production cycle time; for example, it can last from 0.1 to 0.5 seconds, primarily involving electrode depressurization and separation.

[0047] Optionally, step S403 above, which determines the first working parameters of the pre-pressure stage, the second working parameters of the welding stage, and the third working parameters of the pressure holding stage of the spot welding module based on the first attribute parameter, the second attribute parameter, and the weld point position, can be implemented in the following manner: Obtain the first environmental parameters; Based on the first attribute parameter, the second attribute parameter, and the weld point position, corresponding welding records are obtained from the preset spot welding database to obtain a welding records. Each welding record includes a welding quality evaluation value, welding parameters, and reference environmental parameters; a is a positive integer; each welding parameter includes the working parameters of the pre-pressure stage, the working parameters of the welding stage, and the working parameters of the pressure holding stage. Obtain the a environmental parameters corresponding to the a welding records; The a environmental parameters are matched with the first environmental parameter to obtain a matching values; Select the matching values ​​that are greater than a preset matching value from the a matching values ​​to obtain b matching values; b is a positive integer less than or equal to a. Obtain b welding quality evaluation values ​​corresponding to the b matching values, and select the maximum value among the b welding quality evaluation values; Obtain the welding parameters corresponding to the maximum value to obtain the first working parameter, the second working parameter, and the third working parameter.

[0048] The first environmental parameter may include at least one of the following: temperature, humidity, magnetic field interference intensity, atmospheric pressure, etc.

[0049] The reference environmental parameters may include at least one of the following: temperature, humidity, magnetic field interference intensity, atmospheric pressure, etc.

[0050] The preset spot welding database can be pre-set or set by system default. It can include multiple welding records, each corresponding to a spot weld point, a spot weld position, attribute information of an upper-layer automotive workpiece, attribute information of a lower-layer automotive workpiece, a welding quality evaluation value, welding parameters, and reference environmental parameters. Each welding parameter includes working parameters for the pre-pressure stage, the welding stage, and the pressure holding stage.

[0051] Each solder joint position can correspond to a solder joint position identifier, which can be composed of a first attribute information, a second attribute information, and the coordinates of the solder joint position.

[0052] The preset matching value can be set in advance or set by the system default. For example, the preset matching value is 60%.

[0053] Specifically, an environmental sensor can be used to acquire a first environmental parameter. Then, based on the first attribute parameter, the second attribute parameter, and the weld point location, a preset spot welding database is searched to obtain welding records that successfully match the first attribute parameter, the second attribute parameter, and the weld point location, resulting in 'a' welding records. Then, 'a' environmental parameters corresponding to the 'a' welding records are acquired. Each of the 'a' environmental parameters can be matched with the first environmental parameter to obtain 'a' matching values. For example, taking the i-th environmental parameter as an example, the i-th environmental parameter can include c environmental parameters, where c is a positive integer. Each environmental parameter corresponds to a parameter type (e.g., temperature type, humidity type, etc.). Then, the environmental parameter corresponding to each parameter type in the c environmental parameters is matched with the corresponding environmental parameter in the reference environmental parameters to obtain c matching values. Then, c weights corresponding to the c environmental parameters are acquired, with the sum of the c weights being 1. Each parameter type corresponds to a weight. The c matching values ​​and c weights are weighted and calculated to obtain the corresponding matching value.

[0054] Next, select a matching value that is greater than the preset matching value from the a matching values ​​to obtain b matching values, where b is a positive integer less than or equal to a. Then, obtain b welding quality evaluation values ​​corresponding to the b matching values, select the maximum value among the b welding quality evaluation values, and obtain the welding parameters corresponding to the maximum value to obtain the first working parameter, the second working parameter, and the third working parameter.

[0055] In this embodiment, the first environmental parameters of the current welding environment can be obtained in real time by environmental sensors. Combined with the relevant attribute parameters of the upper and lower automotive workpieces and the weld point position, a historical welding records are selected from a preset database to achieve a precise correlation between the welding scene and historical spot welding data. Then, b high-similarity historical spot welding records are selected by environmental parameter matching, and the welding parameters corresponding to the highest quality evaluation value are selected. In this way, the optimal historical spot welding parameters can be matched in real time by environmental parameters, relevant attribute parameters of automotive workpieces, and weld point position to achieve dynamic adaptive adjustment of spot welding parameters. This not only avoids the high cost and low efficiency of manual trial and error, but also ensures the consistency of weld point quality under different environments and different workpieces. Ultimately, it improves the stability, yield, and production efficiency of the spot welding process, and helps to ensure the stability and consistency of batch spot welding in automotive processing.

[0056] S404. Perform electrode pressurization operation according to the solder joint position and the first working parameter, and record the first pressure parameter during the electrode pressurization operation. Adjust the second working parameter according to the first pressure parameter to obtain the target second working parameter. Determine the target third working parameter according to the target second working parameter and the third working parameter.

[0057] In particular, considering that the pressure during the pre-pressing stage in the spot welding process may affect the electrode contact state, the initial deformation of the automotive workpiece, and the stability of the contact resistance, thereby affecting the current distribution, the quality of the weld nugget formation, and the final weld performance during the welding stage, in the specific implementation, during the pre-pressing stage, the vision module and the spot welding module can perform electrode pressurization operation according to the weld position and the first working parameters. During the electrode pressurization operation, the corresponding pressure parameters are collected and recorded to obtain the first pressure parameter. Based on the first pressure parameter, the second working parameter is adjusted to compensate for the impact of the pressure during the pre-pressing stage.

[0058] In practice, the current or duration in the second working parameter can be adjusted according to the first pressure parameter to obtain the target second working parameter. That is, the pressure parameter is collected in real time during the electrode pressurization process, and the working parameters of the welding stage are dynamically adjusted. This can compensate for the actual working condition differences caused by the workpiece assembly gap and contact resistance fluctuation, further ensure the heat input stability of the welding process, and reduce the generation of welding defects.

[0059] Among them, the working parameters of the pressure holding stage can be derived by linking the adjusted working parameters of the welding stage and the initial working parameters of the pressure holding stage, that is, the working parameters of the pressure holding stage can be derived by linking the adjusted working parameters of the welding stage.

[0060] S405. Perform welding operation at the weld joint position according to the target second working parameter, perform pressure holding operation according to the target third working parameter, determine the fourth working parameter for the pressure relief stage according to the target third working parameter, and perform pressure relief operation at the weld joint position according to the fourth working parameter.

[0061] The spot welding module can perform welding operations at the weld point according to the second target working parameters, generating heat by applying electricity to form a weld nugget. The spot welding module can also perform a pressure holding operation at the weld point according to the third target working parameters. After the welding current is cut off, the electrode can maintain pressure for a period of time to prevent shrinkage cavities or cracks from forming in the early stage of solidification of the weld nugget.

[0062] In specific implementation, the fourth working parameter of the pressure relief stage can be determined based on the third working parameter of the target. For example, after the molten core is completely solidified, the electrode is depressurized and separated, the spot welding process ends, and the workpiece is welded.

[0063] Next, the spot welding module can perform a pressure relief operation at the weld point position according to the fourth working parameter, the electrode is depressurized and separated, the spot welding process ends, and the workpiece is welded.

[0064] After spot welding is completed at the weld point, an image of that weld point can be acquired. The quality of the weld point is evaluated based on this image to obtain an evaluation value. Specifically, features can be extracted from the image of the weld point to obtain a first feature set. The first feature set can include at least one of the following: texture, feature vector, feature value, color feature, etc. The first feature set is input into a neural network model to obtain the evaluation value. The neural network model can be a model that has been trained and converged, and it can include lightweight models such as BP neural network, YOLO, EfficientDet, convolutional neural network model, etc. In specific implementation, the model can be trained with massive amounts of data so that the model can capture subtle defects in the weld point (such as 0.1mm level cracks, micro-shrinkage cavities, etc.).

[0065] Furthermore, the first attribute parameters of the upper automotive workpiece, the second attribute parameters of the lower automotive workpiece, the weld point position, the environmental parameters of the environmental sensor, the working parameters of the pre-pressing stage, the working parameters of the welding stage, and the working parameters of the holding pressure stage can be bound together to generate a welding record, which is then stored in a preset spot welding database.

[0066] In this embodiment, firstly, the weld point location is automatically identified by a vision module, and the initial working parameters for each stage of pre-pressing, welding, and holding pressure are adaptively determined based on the material, thickness, and other attribute parameters of the upper and lower automotive workpieces. This avoids weld point misalignment and parameter mismatch caused by manual parameter setting deviations, improving weld point positioning accuracy and welding parameter adaptability from the source. Secondly, pressure parameters are collected in real time during electrode pressurization, and the working parameters for the welding stage are dynamically adjusted based on these pressure parameters. This can compensate for the actual working condition differences caused by workpiece assembly gaps and contact resistance fluctuations, further ensuring the heat input stability of the welding process and reducing welding defects. Thirdly, based on the adjusted welding... The working parameters of each stage are linked with the initial working parameters of the holding stage to derive the working parameters of the holding stage. Then, the working parameters of the depressurization stage are determined based on these parameters. This achieves the correlation optimization of working parameters in each stage of the welding process, avoiding the problem of mismatch in weld nugget stress caused by independent setting of working parameters in each stage. This effectively reduces the risk of defects such as shrinkage cavities and cracks. Through the dynamic perception and correlation adjustment of working parameters in multiple stages, intelligent closed-loop control of spot welding of automotive parts is achieved. This not only improves the consistency of welding quality and yield, but also reduces manual debugging intervention. It helps to ensure the stability of spot welding quality and the spot welding effect in automotive processing, especially in the scenario of batch spot welding of automotive parts.

[0067] Optionally, the first pressure parameter includes the pressure change curve during the pre-compression stage; the above step, adjusting the second working parameter according to the first pressure parameter to obtain the target second working parameter, can be implemented in the following manner: Obtain the standard pressure change curve for the pre-compression stage; the standard pressure change curve includes a first part of the standard pressure change curve for the initial contact period, a second part of the standard pressure change curve for the pressure rise period, and a standard pressure change straight line for the stable holding period; the standard pressure change straight line corresponds to the reference pressure. Determine the target pressure fluctuation parameters based on the pressure change curve; The pre-pressure deviation value is determined based on the standard pressure change line and the pressure change curve. The target second operating parameter is determined based on the target pressure fluctuation parameter, the preset pressure deviation value, and the second operating parameter.

[0068] The first pressure parameter may include the pressure change curve during the pre-compression stage. This can be understood as the pressure change curve generated by real-time pressure acquisition during the actual pre-compression stage. In the preset stage, the corresponding pressure can be acquired according to the specified sampling frequency to obtain multiple pressures. Each pressure corresponds to a sampling time. Based on these multiple pressures and multiple sampling times, the pressure change curve during the pre-compression stage can be aggregated. During the aggregation process, it can be aggregated in stages. For example, the pressure change curve corresponding to the initial contact period, the pressure rise period, and the stable holding period can be aggregated in stages. For example, the spot welding module can integrate a pressure sensor to acquire the corresponding pressure according to the specified sampling frequency. The specified sampling frequency can be preset or defaulted to by the system. For example, the specified sampling frequency may include 1kHz to 10kHz.

[0069] In practice, the standard pressure change curve for the pre-compression stage can be obtained from the first operating parameters. This standard pressure change curve can be preset or set by system default. The standard pressure change curve may include a first part of the standard pressure change curve during the initial contact period, a second part of the standard pressure change curve during the pressure rise period, and a straight line of standard pressure change during the stable holding period. The straight line of standard pressure change corresponds to the reference pressure. The reference pressure can be understood as the preset maximum pressure value for the pre-compression stage.

[0070] In specific implementation, a portion of the pressure change curve corresponding to the stable holding period can be extracted from the pressure change curve, and multiple sampling points can be determined based on this portion of the pressure change curve. For example, a portion of the pressure change curve can be uniformly sampled to obtain multiple sampling points, each sampling point corresponding to a pressure and a sampling time. Based on these multiple sampling points, a fitting line is obtained, with the horizontal axis of the fitting line representing time and the vertical axis representing pressure. The slope of the fitting line is obtained to obtain a first slope. A preset mapping relationship between the slope and pressure fluctuation parameters can be stored in advance, and the target pressure fluctuation parameter corresponding to the first slope can be determined based on this mapping relationship. Alternatively, the mean square error can be calculated based on the pressure of multiple sampling points to obtain a first mean square error. A preset mapping relationship between the mean square error and pressure fluctuation parameters can be stored in advance, and the target pressure fluctuation parameter corresponding to the first mean square error can be determined based on this mapping relationship. Alternatively, the first slope and the second slope can be used as the basis for determining the target pressure fluctuation parameter. The target pressure fluctuation parameter is determined by the mean square deviation. For example, the first pressure fluctuation parameter corresponding to the first slope can be determined based on the preset mapping relationship between the slope and the pressure fluctuation parameter. Then, the second pressure fluctuation parameter corresponding to the first mean square deviation can be determined based on the preset mapping relationship between the mean square deviation and the pressure fluctuation parameter. The first pressure fluctuation parameter and the second pressure fluctuation parameter are weighted to obtain the target pressure fluctuation parameter. For example, the first pressure fluctuation parameter corresponds to the first weight, and the second pressure fluctuation parameter corresponds to the second weight. The sum of the first weight and the second weight is 1. The first weight and the second weight can be preset. For example, the first weight is 0.4 and the second weight is 0.6. The target pressure fluctuation parameter is obtained by weighting the first pressure fluctuation parameter, the second pressure fluctuation parameter, the first weight, and the second weight. That is, the first pressure fluctuation parameter × the first weight + the second pressure fluctuation parameter × the second weight = the target pressure fluctuation parameter.

[0071] The target pressure fluctuation parameter can be a positive value, such as 0~1, for example, the target pressure fluctuation parameter is 5%.

[0072] The main purpose of the stabilization period is to ensure a tight fit between the weldment and stable contact resistance, creating uniform conditions for the subsequent introduction of welding current and the formation of the weld nugget. The magnitude of the target pressure fluctuation parameter also affects ensuring a tight fit between the weldment and stable contact resistance.

[0073] In practice, since the standard pressure change line corresponds to a segment of the stable holding period, the two endpoints of the line can be determined. Based on these two endpoints, the duration of the stable holding period can be determined. Based on this duration, the area corresponding to the standard pressure change line can be determined, and the first area is obtained. The first area = duration of the stable holding period × reference pressure. Similarly, the time points corresponding to the two endpoints mentioned above can be intercepted from the pressure change curve to obtain a time period. Based on this time period, a portion of the pressure change curve is intercepted from the pressure change curve, and the area of ​​this portion of the pressure change curve is determined to obtain the second area. Based on the first area and the second area, the pre-pressure deviation value is determined. The pre-pressure deviation value = (second area - first area) / first area. The pre-pressure deviation value reflects the pressure state in the pre-pressure stage, such as insufficient pressure, appropriate pressure, or excessive pressure. Then, the target second working parameter is determined according to the target pressure fluctuation parameter, the preset pressure deviation value, and the second working parameter. The target pressure fluctuation parameter reflects the pressure stability. Among them, the pre-pressure deviation value has the main influence, and the target pressure fluctuation parameter has the secondary influence. That is, by combining the pressure state in the pre-pressure stage and the stability dynamic optimization of the second working parameter in the welding stage, the actual working condition differences caused by the workpiece assembly gap and contact resistance fluctuation can be compensated, further ensuring the heat input stability of the welding process and reducing the generation of welding defects.

[0074] Optionally, the second working parameter includes a reference welding current and a reference welding duration; the above steps, determining the target second working parameter based on the target pressure fluctuation parameter, the preset pressure deviation value, and the second working parameter, can be implemented in the following manner: When the pre-pressure deviation value is within a first preset range, the target second working parameter is determined according to the second working parameter; the first preset range includes an upper threshold and a lower threshold; When the pre-pressure deviation is less than the lower threshold, a first difference between the lower threshold and the pre-pressure deviation is determined, and the target second working parameter is determined based on the first difference, the target pressure fluctuation parameter, the reference welding current, and the reference welding time. When the pre-pressure deviation value is greater than the upper limit threshold, the difference between the upper limit threshold and the pre-pressure deviation value is determined to obtain a second difference value. The target second working parameter is determined based on the second difference value, the target pressure fluctuation parameter, the reference welding current, and the reference welding time.

[0075] The second operating parameter may include a reference welding current and a reference welding duration, both of which can be preset or set by system default. The first preset range may include an upper threshold and a lower threshold, with the lower threshold being less than the upper threshold.

[0076] When the pre-pressure deviation is within the first preset range, that is, when the pre-pressure deviation is greater than or equal to the lower threshold and less than or equal to the upper threshold, it indicates that the pressure is appropriate, and the second working parameter can be directly used as the target second working parameter.

[0077] When the pre-pressure deviation is less than the lower threshold, it indicates insufficient pressure, which leads to increased contact resistance and concentrated heat, making it prone to spatter, uneven welds, or even incomplete welds. Heat input can be controlled by adjusting the current (reducing) and duration (shortening) of the welding stage. The first difference between the lower threshold and the pre-pressure deviation can be determined: First difference = Lower threshold - Pre-pressure deviation. Based on the first difference, target pressure fluctuation parameters, reference welding current, and reference welding duration, the target second working parameters are determined. This means reducing the current and shortening the time in the second working parameters, and / or shortening the duration. By combining the pressure state and stability of the pre-pressure stage with dynamic optimization of the second working parameters of the welding stage, the actual working condition differences caused by workpiece assembly gaps and contact resistance fluctuations can be compensated, further ensuring the stability of heat input during the welding process and reducing welding defects.

[0078] When the pre-pressure deviation exceeds the upper limit threshold, it indicates excessive pressure, which leads to decreased contact resistance and accelerated heat dissipation. This can result in insufficient weld nugget size or inadequate weld strength. Heat loss can be compensated by adjusting the current (increase) and duration (extend) of the welding stage. The difference between the upper limit threshold and the pre-pressure deviation can be determined, yielding a second difference: second difference = pre-pressure deviation - upper limit threshold. Based on the second difference, target pressure fluctuation parameters, reference welding current, and reference welding duration, target second working parameters can be determined. This means increasing the current and extending the time in the second working parameters. By combining the pressure state and stability of the pre-pressure stage, the second working parameters of the welding stage can be dynamically optimized to compensate for the actual working condition differences caused by workpiece assembly gaps and contact resistance fluctuations, further ensuring the stability of heat input during the welding process and reducing welding defects.

[0079] Optionally, the above steps, in which the target second working parameter is determined based on the first difference, the target pressure fluctuation parameter, the reference welding current, and the reference welding time, can be implemented in the following manner: The first current adjustment parameter and the first duration adjustment parameter are determined based on the first difference; The first current fine-tuning parameter and the first duration fine-tuning parameter are determined based on the target pressure fluctuation parameter. The target second working parameter is determined based on the first current adjustment parameter, the first duration adjustment parameter, the first current fine-tuning parameter, the first duration fine-tuning parameter, the reference welding current, and the reference welding duration.

[0080] In specific implementation, a first mapping relationship between preset differences and current adjustment parameters can be stored in advance. Based on this first mapping relationship, a first current adjustment parameter corresponding to the first difference is determined. Similarly, a second mapping relationship between preset differences and duration adjustment parameters can be stored in advance. Based on this second mapping relationship, a first duration adjustment parameter corresponding to the first difference is determined. Both the current adjustment parameter and the duration adjustment parameter can be preset or set by system default. For example, the value range of the current adjustment parameter can be 0 to 1, or 0.1 for example, and the value range of the duration adjustment parameter can be 0 to 1, or 0.1 for example.

[0081] Specifically, a third mapping relationship between preset pressure fluctuation parameters and current fine-tuning parameters can be stored in advance. Based on this third mapping relationship, a first current fine-tuning parameter corresponding to the target pressure fluctuation parameter can be determined. A fourth mapping relationship between preset pressure fluctuation parameters and duration fine-tuning parameters can also be stored in advance. Based on this fourth mapping relationship, a first duration fine-tuning parameter corresponding to the target pressure fluctuation parameter can be determined. Both the current fine-tuning parameter and the duration fine-tuning parameter can be preset or set to system defaults. For example, the value range of the current fine-tuning parameter is 0~0.04, or 0.02. The value range of the duration fine-tuning parameter is 0~0.02, or 0.02.

[0082] Next, the target second working parameters can be determined based on the first current adjustment parameter, the first duration adjustment parameter, the first current fine-tuning parameter, the first duration fine-tuning parameter, the reference welding current, and the reference welding duration. Specifically, the target welding current = reference welding current × (1 - first current adjustment parameter) × (1 + first current fine-tuning parameter), and the target welding duration = reference welding duration × (1 - first current adjustment parameter) × (1 + first duration fine-tuning parameter). That is, the current can be reduced and the time shortened, i.e., the current in the second working parameters can be reduced, and / or the duration in the second working parameters can be shortened. In other words, by combining the pressure state of the pre-pressing stage and the stability dynamic optimization of the second working parameters of the welding stage, the actual working condition differences caused by the workpiece assembly gap and contact resistance fluctuations can be compensated, further ensuring the heat input stability of the welding process and reducing the generation of welding defects.

[0083] Optionally, the above steps, in which the target second working parameter is determined based on the second difference, the target pressure fluctuation parameter, the reference welding current, and the reference welding time, can be implemented in the following manner: The second current adjustment parameter and the second duration adjustment parameter are determined based on the second difference. The second current fine-tuning parameter and the second duration fine-tuning parameter are determined based on the target pressure fluctuation parameter. The target second working parameter is determined based on the second current adjustment parameter, the second duration adjustment parameter, the second current fine-tuning parameter, the second duration fine-tuning parameter, the reference welding current, and the reference welding duration.

[0084] In specific implementation, a fifth mapping relationship between preset differences and current adjustment parameters can be stored in advance. Based on this fifth mapping relationship, the second current adjustment parameter corresponding to the second difference is determined. Similarly, a sixth mapping relationship between preset differences and duration adjustment parameters can be stored in advance. Based on this sixth mapping relationship, the second duration adjustment parameter corresponding to the second difference is determined. Both the current adjustment parameter and the duration adjustment parameter can be preset or set by system default. For example, the value range of the current adjustment parameter can be 0~1, or 0.1; and the value range of the duration adjustment parameter can be 0~1, or 0.1.

[0085] The system can pre-store a seventh mapping relationship between preset pressure fluctuation parameters and current fine-tuning parameters. Based on this seventh mapping relationship, a second current fine-tuning parameter corresponding to the target pressure fluctuation parameter can be determined. It can also pre-store an eighth mapping relationship between preset pressure fluctuation parameters and duration fine-tuning parameters. Based on this eighth mapping relationship, a second duration fine-tuning parameter corresponding to the target pressure fluctuation parameter can be determined. Both the current fine-tuning parameter and the duration fine-tuning parameter can be preset or set to system defaults. For example, the value range of the current fine-tuning parameter is 0~0.04, or 0.02. The value range of the duration fine-tuning parameter is 0~0.02, or 0.02.

[0086] Next, the target second working parameters can be determined based on the second current adjustment parameter, the second duration adjustment parameter, the second current fine-tuning parameter, the second duration fine-tuning parameter, the reference welding current, and the reference welding duration. Specifically, the target welding current = reference welding current × (1 + second current adjustment parameter) × (1 + second current fine-tuning parameter), and the target welding duration = reference welding duration × (1 + second current adjustment parameter) × (1 + second duration fine-tuning parameter). That is, the current can be increased and the time extended, i.e., the current in the second working parameters can be increased, and / or the duration in the second working parameters can be extended. In other words, by combining the pressure state of the pre-pressing stage and the stability dynamic optimization of the second working parameters in the welding stage, the actual working condition differences caused by the workpiece assembly gap and contact resistance fluctuations can be compensated, further ensuring the heat input stability of the welding process and reducing the generation of welding defects.

[0087] Optionally, the target second working parameter includes: target welding time and target welding current; the third working parameter includes a first reference time; the above step of determining the target third working parameter based on the target second working parameter and the third working parameter can be implemented in the following manner: Based on a first deviation value between the target welding current and the reference welding current; Determine a second deviation value between the target welding time and the reference welding time; The first adjustment parameter is determined based on the first deviation value; The first fine-tuning parameter is determined based on the second deviation value; The first reference duration is adjusted according to the first adjustment parameter and the first fine-tuning parameter to obtain the target third working parameter.

[0088] In practice, increasing the current and duration during the welding stage significantly increases the heat of the weld nugget, leading to an increase in its volume and temperature. This necessitates a longer holding time to allow for heat dissipation and solidification; otherwise, problems such as incomplete solidification, insufficient weld strength, or electrode adhesion may occur. Conversely, decreasing the current and duration during the welding stage reduces the heat of the weld nugget, resulting in a lower temperature and smaller volume. This shortens the time required for cooling and solidification, allowing for a corresponding reduction in the holding time. Since the current during the welding stage has a far greater impact on the holding time than the duration of the welding stage, the current during the welding stage is the primary influence, while the duration is a secondary influence.

[0089] In practice, the first deviation value between the target welding current and the reference welding current can be determined, where the first deviation value is equal to (target welding current - reference welding current) / reference welding current. Then, the second deviation value between the target welding time and the reference welding time can be determined, where the second deviation value is equal to (target welding time - reference welding time) / reference welding time.

[0090] Next, a pre-stored mapping relationship between preset deviation values ​​and adjustment parameters can be established. Based on this mapping relationship, a first adjustment parameter corresponding to the first deviation value is determined. The range of the adjustment parameter can be preset or defaulted to by the system, and the range can be -0.3 to 0.3. Similarly, a pre-stored mapping relationship between preset deviation values ​​and fine-tuning parameters can be established. The range of the fine-tuning parameter can be preset or defaulted to by the system, and the range can be -0.05 to 0.05. Based on this mapping relationship, a first fine-tuning parameter corresponding to the second deviation value is determined. Then, the first reference duration is adjusted according to the first adjustment parameter and the first fine-tuning parameter to obtain the target third working parameter. The target third working parameter = (1 + first adjustment parameter) × (1 + first fine-tuning parameter) × first reference duration. Since the third working parameter is preset, and the working parameters of the welding stage are based on the pre-pressure stage... With the pre-stressing effect adjusted accordingly, the third working parameter can be dynamically adjusted based on this adjustment, realizing the correlation optimization of working parameters at each stage of the welding process. This avoids the problem of mismatched weld nugget stress caused by independent setting of working parameters at each stage, effectively reducing the risk of defects such as shrinkage cavities and cracks. Through the dynamic perception and correlation adjustment of working parameters at multiple stages, intelligent closed-loop control of spot welding of automotive parts can be achieved, which not only improves the consistency of welding quality and yield, but also reduces manual debugging intervention. This helps to ensure the stability of spot welding quality and the spot welding effect in the automotive processing process, especially in the scenario of batch spot welding of automotive parts.

[0091] Optionally, the target third operating parameter includes a second reference duration; the above steps, determining the fourth operating parameter for the depressurization stage based on the target third operating parameter, can be implemented as follows: Collect the melting nugget temperature values ​​during the pressure holding stage to obtain multiple melting nugget temperature values; The first fluctuation parameter is determined based on the multiple melting core temperature values; The fourth operating parameter is determined based on the first fluctuation parameter and the second reference duration.

[0092] In practice, the holding pressure stage is used to cool the weld nugget and complete solidification, while the depressurization stage is used to separate the electrodes and release stress. The depressurization time should be set based on the holding pressure time to ensure that the weld nugget is completely solidified before depressurization, thus avoiding weld defects. For example, the depressurization time is usually 10% to 30% of the holding pressure time.

[0093] In specific implementation, the spot welding system may also include a temperature detection module. The target third working parameter includes a second reference duration. During the pressure holding stage, the temperature detection module can collect the molten nugget temperature value during the pressure holding stage to obtain multiple molten nugget temperature values. Each molten nugget temperature value can correspond to a sampling time. Then, based on the multiple molten nugget temperature values, the first fluctuation parameter is determined. Specifically, the multiple molten nugget temperature values ​​and their corresponding sampling times can correspond to multiple coordinate points. Based on these multiple coordinate points, a temperature change line can be obtained. The horizontal axis of the corresponding coordinate system is time, and the vertical axis is temperature. The absolute value of the slope of the temperature change line is obtained to obtain the first absolute value. According to the preset mapping relationship between the absolute value and the fluctuation parameter, the first fluctuation parameter corresponding to the first absolute value can be determined based on this mapping relationship. The larger the first absolute value, the faster the molten nugget temperature decays; conversely, the smaller the first absolute value, the slower the molten nugget temperature decays.

[0094] Specifically, reference fluctuation parameters can be obtained. These parameters can be preset or defaulted to by the system. They reflect the normal decay of the melt core temperature. The reference fluctuation parameters can be related to the material of the automotive workpiece or the processing environment. A first fluctuation deviation value is determined based on the first fluctuation parameter and the reference fluctuation parameter: First fluctuation deviation value = (First fluctuation parameter - Reference fluctuation parameter) / Reference fluctuation parameter. A preset mapping relationship between fluctuation deviation values ​​and optimization parameters can be stored in advance. Based on this mapping relationship, the first optimization parameter corresponding to the first fluctuation deviation value is determined. Then, a fourth working parameter is determined based on the first optimization parameter and the second reference duration: Fourth working parameter = Second reference duration × a × (1 + First optimization parameter), where a is a constant, for example, a value of 0.1~0.3. The value range of the first optimization parameter can be preset or defaulted to by the system, for example, -0.1~0.1. On the one hand, the duration of the depressurization stage is deeply related to the duration of the holding stage; on the other hand, the depressurization duration is dynamically optimized by combining the melt core temperature decay law, thereby dynamically adjusting the depressurization duration to ensure complete solidification of the melt core while optimizing production efficiency.

[0095] For example, Figure 5As shown in the embodiment of this application, the entire spot welding process can be divided into four stages: pre-pressure stage, welding stage, pressure holding stage, and pressure release stage. The pre-pressure stage corresponds to the first working parameter, the welding stage corresponds to the second working parameter, and the pressure holding stage corresponds to the third working parameter. The first, second, and third working parameters can all be set using big data technology based on the welding position and the relevant attribute parameters of the upper and lower automotive workpieces. In the pre-pressure stage, the pressure change during the stable holding period is considered to evaluate the pre-pressure effect. Then, based on the influence of this pressure change, the second working parameter is dynamically adjusted to obtain a target second working parameter for the welding stage that is more suitable for the current pre-pressure condition. Since the second working parameter is adjusted... The process requires coordinated adjustment of the third working parameter to obtain the most suitable target third working parameter for the pressure holding stage. Finally, the fourth working parameter is determined based on the target third working parameter, realizing the correlation optimization of working parameters at each stage of the welding process. This avoids the problem of mismatched weld nugget stress caused by independent setting of working parameters at each stage, effectively reducing the risk of defects such as shrinkage cavities and cracks. Through the dynamic perception and correlation adjustment of working parameters at multiple stages, intelligent closed-loop control of spot welding of automotive parts is achieved. This not only improves the consistency of welding quality and yield, but also reduces manual debugging intervention, which helps to ensure the stability of spot welding quality and the spot welding effect in the automotive processing process, especially in the scenario of batch spot welding of automotive parts.

[0096] In specific implementation, based on the spot welding method and system described in the embodiments of this application, the corresponding spot welding operation can be completed for any spot welding point during the batch processing of automotive workpieces, ensuring the stability of spot welding quality and the spot welding effect.

[0097] Consistent with the above embodiments, please refer to Figure 6 , Figure 6 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. The electronic device includes a processor, a memory, a communication interface, and one or more programs. The one or more programs are stored in the memory and configured to be executed by the processor. In this embodiment, the programs include instructions for performing the following steps: The upper-layer automotive workpiece is photographed to obtain a first image, and the weld point position is determined based on the first image; the upper-layer automotive workpiece is fixed by a first fixing module, and the lower-layer automotive workpiece is fixed by a second fixing module. Determine the first attribute parameter of the upper automotive workpiece and the second attribute parameter of the lower automotive workpiece corresponding to the weld point position; The first working parameters for the pre-pressing stage, the second working parameters for the welding stage, and the third working parameters for the pressure holding stage are determined based on the first attribute parameter, the second attribute parameter, and the weld point position. Perform electrode pressurization operation according to the solder joint position and the first working parameter, record the first pressure parameter during the electrode pressurization operation, adjust the second working parameter according to the first pressure parameter to obtain the target second working parameter, and determine the target third working parameter according to the target second working parameter and the third working parameter. Welding is performed at the weld joint location according to the target second working parameters, pressure holding is performed according to the target third working parameters, a fourth working parameter for the pressure relief stage is determined based on the target third working parameters, and a pressure relief operation is performed at the weld joint location according to the fourth working parameters.

[0098] The electronic device can be applied to a spot welding system, which includes a vision module, a first fixing module, a second fixing module, a spot welding module, and a control module. The electronic device may include the control module. Alternatively, the electronic device may also comprise the spot welding system itself.

[0099] This application also provides a computer storage medium storing a computer program for electronic data interchange, which causes a computer to perform some or all of the steps of any of the methods described in the above method embodiments, wherein the computer includes an electronic device.

[0100] This application also provides a computer program product, which includes a non-transitory computer-readable storage medium storing a computer program operable to cause a computer to perform some or all of the steps of any of the methods described in the above method embodiments. The computer program product may be a software installation package, and the computer may include an electronic device.

[0101] It should be noted that, for the sake of simplicity, the foregoing method embodiments are all described as a series of actions. However, those skilled in the art should understand that this application is not limited to the described order of actions, as some steps may be performed in other orders or simultaneously according to this application. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions and modules involved are not necessarily essential to this application.

[0102] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0103] In the several embodiments provided in this application, it should be understood that the disclosed apparatus can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of the units described above is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between devices or units may be electrical or other forms.

[0104] The units described above as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0105] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0106] If the aforementioned integrated units are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage device (CMD). Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a memory and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned memory includes various media capable of storing program code, such as USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks.

[0107] Those skilled in the art will understand that all or part of the steps in the various methods of the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage device, which may include: a flash drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk, etc.

[0108] The embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A spot welding method, characterized in that, The method includes: The upper-layer automotive workpiece is photographed to obtain a first image, and the weld point position is determined based on the first image; the upper-layer automotive workpiece is fixed by a first fixing module, and the lower-layer automotive workpiece is fixed by a second fixing module. Determine the first attribute parameter of the upper automotive workpiece and the second attribute parameter of the lower automotive workpiece corresponding to the weld point position; The first working parameters for the pre-pressing stage, the second working parameters for the welding stage, and the third working parameters for the pressure holding stage are determined based on the first attribute parameter, the second attribute parameter, and the weld point position. Perform electrode pressurization operation according to the solder joint position and the first working parameter, record the first pressure parameter during the electrode pressurization operation, adjust the second working parameter according to the first pressure parameter to obtain the target second working parameter, and determine the target third working parameter according to the target second working parameter and the third working parameter. Welding is performed at the weld joint location according to the target second working parameters, pressure holding is performed according to the target third working parameters, a fourth working parameter for the pressure relief stage is determined based on the target third working parameters, and a pressure relief operation is performed at the weld joint location according to the fourth working parameters.

2. The method as described in claim 1, characterized in that, The first pressure parameter includes the pressure change curve during the pre-compression stage; adjusting the second operating parameter based on the first pressure parameter to obtain the target second operating parameter includes: Obtain the standard pressure change curve for the pre-compression stage; the standard pressure change curve includes a first part of the standard pressure change curve for the initial contact period, a second part of the standard pressure change curve for the pressure rise period, and a standard pressure change straight line for the stable holding period; the standard pressure change straight line corresponds to the reference pressure. Determine the target pressure fluctuation parameters based on the pressure change curve; The pre-pressure deviation value is determined based on the standard pressure change line and the pressure change curve. The target second operating parameter is determined based on the target pressure fluctuation parameter, the preset pressure deviation value, and the second operating parameter.

3. The method as described in claim 2, characterized in that, The second operating parameters include a reference welding current and a reference welding duration; Determining the target second operating parameter based on the target pressure fluctuation parameter, the preset pressure deviation value, and the second operating parameter includes: When the pre-pressure deviation value is within a first preset range, the target second working parameter is determined according to the second working parameter; the first preset range includes an upper threshold and a lower threshold; When the pre-pressure deviation is less than the lower threshold, a first difference between the lower threshold and the pre-pressure deviation is determined, and the target second working parameter is determined based on the first difference, the target pressure fluctuation parameter, the reference welding current, and the reference welding time. When the pre-pressure deviation value is greater than the upper limit threshold, the difference between the upper limit threshold and the pre-pressure deviation value is determined to obtain a second difference value. The target second working parameter is determined based on the second difference value, the target pressure fluctuation parameter, the reference welding current, and the reference welding time.

4. The method as described in claim 3, characterized in that, The step of determining the target second working parameter based on the first difference, the target pressure fluctuation parameter, the reference welding current, and the reference welding duration includes: The first current adjustment parameter and the first duration adjustment parameter are determined based on the first difference; The first current fine-tuning parameter and the first duration fine-tuning parameter are determined based on the target pressure fluctuation parameter. The target second working parameter is determined based on the first current adjustment parameter, the first duration adjustment parameter, the first current fine-tuning parameter, the first duration fine-tuning parameter, the reference welding current, and the reference welding duration.

5. The method as described in claim 3, characterized in that, The step of determining the target second operating parameter based on the second difference, the target pressure fluctuation parameter, the reference welding current, and the reference welding duration includes: The second current adjustment parameter and the second duration adjustment parameter are determined based on the second difference. The second current fine-tuning parameter and the second duration fine-tuning parameter are determined based on the target pressure fluctuation parameter. The target second working parameter is determined based on the second current adjustment parameter, the second duration adjustment parameter, the second current fine-tuning parameter, the second duration fine-tuning parameter, the reference welding current, and the reference welding duration.

6. The method according to any one of claims 3-5, characterized in that, The target second working parameter includes: target welding time and target welding current; the third working parameter includes a first reference time; determining the target third working parameter based on the target second working parameter and the third working parameter includes: Based on a first deviation value between the target welding current and the reference welding current; Determine a second deviation value between the target welding time and the reference welding time; The first adjustment parameter is determined based on the first deviation value; The first fine-tuning parameter is determined based on the second deviation value; The first reference duration is adjusted according to the first adjustment parameter and the first fine-tuning parameter to obtain the target third working parameter.

7. The method according to any one of claims 1-5, characterized in that, The target third operating parameter includes a second reference duration; the determination of the fourth operating parameter for the depressurization stage based on the target third operating parameter includes: Collect the melting nugget temperature values ​​during the pressure holding stage to obtain multiple melting nugget temperature values; The first fluctuation parameter is determined based on the multiple melting core temperature values; The fourth operating parameter is determined based on the first fluctuation parameter and the second reference duration.

8. The method according to any one of claims 1-5, characterized in that, The step of determining the first working parameters for the pre-pressure stage, the second working parameters for the welding stage, and the third working parameters for the pressure holding stage based on the first attribute parameter, the second attribute parameter, and the weld point position includes: Obtain the first environmental parameters; Based on the first attribute parameter, the second attribute parameter, and the weld point position, corresponding welding records are obtained from the preset spot welding database to obtain a welding records. Each welding record includes a welding quality evaluation value, welding parameters, and reference environmental parameters; a is a positive integer; each welding parameter includes the working parameters of the pre-pressure stage, the working parameters of the welding stage, and the working parameters of the pressure holding stage. Obtain the a environmental parameters corresponding to the a welding records; The a environmental parameters are matched with the first environmental parameter to obtain a matching values; Select the matching values ​​that are greater than a preset matching value from the a matching values ​​to obtain b matching values; b is a positive integer less than or equal to a. Obtain b welding quality evaluation values ​​corresponding to the b matching values, and select the maximum value among the b welding quality evaluation values; Obtain the welding parameters corresponding to the maximum value to obtain the first working parameter, the second working parameter, and the third working parameter.

9. A spot welding system, characterized in that, The spot welding system includes: a vision module, a first fixing module, a second fixing module, a spot welding module, and a control module, wherein... The first fixing module is used to fix the upper automotive workpiece; The second fixing module is used to fix the lower automotive workpiece; The vision module is used to photograph the upper automotive workpiece to obtain a first image, and to determine the location of the weld point based on the first image. The control module is used to determine the first attribute parameters of the upper automotive workpiece and the second attribute parameters of the lower automotive workpiece corresponding to the weld point position; and to determine the first working parameters of the pre-pressing stage, the second working parameters of the welding stage, and the third working parameters of the pressure holding stage based on the first attribute parameters, the second attribute parameters, and the weld point position. The control module is further configured to: execute an electrode pressurization operation based on the weld point position and the first working parameters using the vision module and the spot welding module; record a first pressure parameter during the electrode pressurization operation; adjust the second working parameters based on the first pressure parameter to obtain a target second working parameter; determine a target third working parameter based on the target second working parameter and the third working parameter; execute a welding operation at the weld point position according to the target second working parameter using the spot welding module; execute a pressure holding operation at the weld point position according to the target third working parameter; determine a fourth working parameter for the pressure release stage based on the target third working parameter; and execute a pressure release operation at the weld point position according to the fourth working parameter using the spot welding module.

10. The system as described in claim 9, characterized in that, The first pressure parameter includes the pressure change curve during the pre-compression stage; regarding the adjustment of the second operating parameter based on the first pressure parameter to obtain the target second operating parameter, the control module is specifically used for: Obtain the standard pressure change curve for the pre-compression stage; the standard pressure change curve includes a first part of the standard pressure change curve for the initial contact period, a second part of the standard pressure change curve for the pressure rise period, and a standard pressure change straight line for the stable holding period; the standard pressure change straight line corresponds to the reference pressure. Determine the target pressure fluctuation parameters based on the pressure change curve; The pre-pressure deviation value is determined based on the standard pressure change line and the pressure change curve. The target second operating parameter is determined based on the target pressure fluctuation parameter, the preset pressure deviation value, and the second operating parameter.

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