A method and system for real-time monitoring and control of welding distortion of a metal component

Abstract

The present application relates to the technical field of welding deformation monitoring, in particular to a metal component welding deformation real-time monitoring control method and system. By obtaining three-dimensional displacement vector and Euler angle in the welding process, the bending curvature is calculated by the angle difference of adjacent monitoring points, the unit length torsion angle is calculated by the angle difference of symmetrical monitoring points, and the out-of-plane warping displacement is extracted by rigid body registration and local area, the complex deformation is decomposed into bending, torsion and warping three modes, the corresponding strain energy is calculated to construct the deformation state quantity, and the decoupling of multi-mode coupled deformation is realized. The unit length heat input is constructed by introducing welding voltage, current and speed, and the deformation prediction model of next time is established combined with the deformation state quantity, which can reflect the accumulation and dynamic evolution of welding deformation. According to the deviation between the predicted deformation and the target threshold, the welding current adjustment amount and the welding speed adjustment amount are generated respectively, the welding parameters are optimized, and the monitoring precision of welding deformation is improved.

Description

Technical Field

[0001] This invention relates to the field of welding deformation monitoring technology, specifically to a method and system for real-time monitoring and control of welding deformation of metal components. Background Technology

[0002] During the welding of metal components, complex thermo-elastic-plastic deformations, including bending, torsion, and localized warping, are easily triggered due to localized high-temperature heat input and its uneven distribution. These deformations not only affect the dimensional accuracy of the components but may also lead to residual stress concentration and even service failure. Current welding deformation control methods are mainly based on displacement or strain index analysis, failing to effectively distinguish the coupling effects between different deformation modes, resulting in insufficient accuracy in deformation characterization. Furthermore, a quantitative relationship between welding process parameters and structural deformation has not yet been established, and the intrinsic mechanism analysis between heat input and deformation evolution is lacking. This leads to control strategies that are highly dependent on experience and uncertain, making it difficult to achieve stable and precise control of welding deformation. Summary of the Invention

[0003] To address the aforementioned shortcomings of existing technologies, this invention provides a method and system for real-time monitoring and control of welding deformation in metal components. This method effectively solves the problem in existing technologies that lack analysis of bending deformation, torsional deformation, and warping deformation during welding, making it difficult to achieve stable and precise control of welding deformation.

[0004] To achieve the above objectives, the present invention provides the following technical solution: This invention provides a method and system for real-time monitoring and control of welding deformation of metal components, comprising at least: Acquire reference position data of metal components in unwelded state, and set up monitoring points along the weld path to collect displacement data and corresponding angle data relative to the reference position data, as well as welding voltage, welding current and welding speed. Based on the displacement and angle data, the deformation modes of the metal component are decomposed, and the bending modal strain energy, torsional modal strain energy, and warping modal strain energy are calculated respectively to obtain deformation state quantities characterizing the overall deformation degree, wherein: The bending modal strain energy is determined by the angle difference between adjacent monitoring points about the axis perpendicular to the weld direction and the spacing to determine the degree of bending, and the bending deformation energy of each structural section is accumulated. Torsional modal strain energy is determined based on the angular difference between each monitoring point and the axis of the component, combined with the lateral distance, to determine the degree of torsion, and to accumulate the torsional deformation energy of each monitoring point pair; The warping modal strain energy is based on the ideal plane fitted by the monitoring points, and the out-of-plane displacement of each monitoring point relative to the ideal plane is calculated to characterize the energy of local warping deformation. Based on the deformation state quantity and the welding voltage, welding current and welding speed in the welding process state data, a deformation prediction model is constructed to obtain the deformation prediction quantity at the next moment. Based on the deviation between the predicted deformation and the preset threshold, welding current adjustment and welding speed adjustment are generated to control the welding process.

[0005] Furthermore, the method for determining the bending modal strain energy is as follows: Select adjacent monitoring points sequentially along the weld direction, and take the distance between any two adjacent monitoring points as the length of a structural section. For each structural segment, calculate the angular difference between the monitoring points at both ends of the segment about the axis perpendicular to the weld direction, and use the ratio of this angular difference to the length of the corresponding structural segment to obtain the curvature of the segment, which reflects the degree of bending. The curvature corresponds to the length of the structural segment, and the bending equivalent stiffness is weighted and summed for all structural segments to obtain the overall bending modal strain energy.

[0006] Furthermore, the method for determining the torsional modal strain energy is as follows: Select monitoring point pairs that are symmetrically arranged along the transverse direction of the weld, and use the initial transverse distance between each pair of monitoring points as the reference length; For each pair of monitoring points, calculate the angular difference around the axis of the component, and use the ratio of this angular difference to the corresponding initial lateral distance to obtain the torsion angle per unit length. The torsion angle per unit length and the initial lateral distance are used in the calculation, along with the equivalent torsional stiffness. By summing the results from all monitoring points, the torsional modal strain energy is obtained. Furthermore, the method for determining the warping modal strain energy is specifically as follows: The real-time coordinates of all monitoring points are rigidly registered, minimizing the overall deviation between the coordinates of all monitoring points at the current moment and their initial coordinates under the reference pose data, thus eliminating the effects of overall translation and overall rotation. The metal component is divided into multiple local sub-regions. No less than a preset number of monitoring points are selected in each local sub-region. Based on the initial coordinates of the selected monitoring points under the reference pose data, the ideal plane is obtained by fitting through the principle of minimum error. For each monitoring point within a local sub-region, the current coordinates after rigid body registration are substituted into the ideal plane to calculate the vertical deviation of the monitoring point relative to the ideal plane, which is then used as the out-of-plane displacement. The warping intensity of the local sub-region is obtained by performing root mean square processing on the out-of-plane displacement of all monitoring points within the same local sub-region. The warping modal strain energy is obtained based on the warping strength and the warping equivalent stiffness.

[0007] Furthermore, the method for determining the equivalent bending stiffness is as follows: If the cross-sectional shape of the metal component along the weld direction is regular: The bending equivalent stiffness is calculated based on the product of the elastic modulus of the metallic component material and the moment of inertia of the cross section about the bending axis, where: For a rectangular cross-section, the moment of inertia is determined based on the width and height of the cross-section. If the cross-sectional shape is irregular: Before welding, a region is selected on the metal component that avoids the weld location. A known bending moment is applied, and the angle difference is measured using monitoring points and the curvature is calculated. The bending equivalent stiffness is calculated based on the ratio of the known bending moment to the curvature.

[0008] The method for determining the torsional equivalent stiffness is as follows: If the cross-sectional shape of the metal component along the weld direction is regular: calculate the torsional equivalent stiffness based on Poisson's ratio, elastic modulus, and torsional constant of the cross-section; When the cross-sectional shape is irregular, a known torque is applied to a metal component or a specimen of the same material, the angle of torsion per unit length is measured, and the torsional equivalent stiffness is obtained based on the ratio of the known torque to the angle of torsion per unit length.

[0009] Furthermore, the method for determining the warping equivalent stiffness also includes: A local sub-region is selected in the non-welded area of ​​the metal component, a known concentrated force is applied, and the warping displacement of the center point of the region is measured. The warping equivalent stiffness is obtained by the ratio of the known concentrated force to the warping displacement.

[0010] The technical solution provided by this invention has the following advantages compared with the known prior art: By acquiring three-dimensional displacement vectors and Euler angles during welding, the bending curvature is calculated based on the rotational angle difference between adjacent monitoring points, and the torsional angle per unit length is calculated based on the angular difference between symmetrical monitoring points. Combined with rigid body registration and extraction of out-of-plane warping displacement in local areas, complex deformation is decomposed into three modes: bending, torsion, and warping. The corresponding strain energy is calculated to construct deformation state variables, thus decoupling multimodal coupled deformation. Welding voltage, current, and velocity are introduced to construct the heat input per unit length, and a deformation prediction model for the next moment is established based on the deformation state variables. This model reflects the cumulative nature and dynamic evolution of welding deformation. Based on the deviation between the predicted deformation and the target threshold, welding current and welding speed adjustment amounts are generated, optimizing welding parameters and improving the accuracy of welding deformation monitoring. Attached Figure Description

[0011] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.

[0012] Figure 1 This is a schematic diagram of the overall method of the present invention. Detailed Implementation

[0013] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0014] The present invention will be further described below with reference to embodiments.

[0015] Example 1 (see Figure 1 A method for real-time monitoring and control of welding deformation of metal components, comprising at least: Step S1: Perform three-dimensional geometric measurements on the unwelded metal component to obtain its initial spatial pose (the component's position and orientation in three-dimensional space, including the coordinates of each point; whether the component is tilted or rotated, i.e., its orientation), which serves as the reference pose data for all subsequent displacement data. Based on this, multiple monitoring points are deployed along the weld path and the heat-affected zones on both sides, forming a monitoring point set. The spatial position of each monitoring point is described by three-dimensional coordinates, i.e., the i-th monitoring point is represented as... , This indicates the initial coordinates of the monitoring point under the reference pose data.

[0016] Step S2: During the welding process, each monitoring point is measured in real time to obtain its displacement data relative to the reference pose data at the current time t. and the angle data corresponding to the attitude change Among them, displacement data Indicates the current position and initial position of the monitoring point Offset and angle data between This represents the rotational change of the local attitude at that point relative to its initial state. Simultaneously, process parameters during the welding process are collected, including welding voltage. Welding current and welding speed All the above data will be combined to form welding process status data. In this embodiment, the displacement data is a three-dimensional displacement vector. The angle data are three-dimensional Euler angles. .

[0017] Step S3: Further, based on the welding process state data S(t) obtained in Step 2, using the angle and displacement data of the monitoring points, modal decomposition of the structural deformation is performed, and the strain energy corresponding to bending, torsion, and warping is calculated respectively, including: 1) Calculation of bending modal strain energy: Along the weld direction, adjacent monitoring points are selected, and the structural segment formed by the adjacent monitoring points is defined as segment s. Segment s consists of the i-th monitoring point and the (i+1)-th monitoring point. The calculation is based on the rotation angle of the adjacent monitoring points around the y-axis (perpendicular to the weld plane; the bending deformation caused by welding is mainly manifested as the metal component rotating around an axis perpendicular to the weld, i.e., the y-axis, causing the component to warp vertically in the xy plane). Calculate the curvature of this segment: in, Let represent the curvature of segment s at time t. This curvature reflects the rate of change of angle per unit length, i.e., the bending strength. s represents the structural segment index. This represents the length of the s-th segment and the spatial distance (measured before welding) between the ith monitoring point and the (i+1)th monitoring point. This represents the rotation angle of the i-th monitoring point around the y-axis at time t, which is the change relative to the initial state; Furthermore, the length of the combined segment after squaring the curvature is calculated. Equivalent stiffness to bending (Used to characterize the ability of a metal component to resist bending deformation), the bending strain energy of this segment is obtained. Summing over all segments yields the total bending modal strain energy. : For bending equivalent stiffness If the cross-sectional shape of the metal component along the weld direction is regular, such as rectangular or I-shaped: E represents the elastic modulus of the metal component material, and I represents the moment of inertia of the cross-section of the metal component about the bending axis (i.e., the y-axis perpendicular to the weld). For a rectangular cross-section, 'b' represents the width of the metal component cross-section, and 'h' represents the height of the metal component cross-section. If the cross-sectional shape is irregular: Before welding, select a region on the metal component that avoids the weld seam, apply a known bending moment M, which can be done by suspending weights or using a hydraulic actuator. Measure the angle difference using monitoring points and calculate the curvature (as described above). The calculation process involves calculating the equivalent bending stiffness based on the ratio of the known bending moment M1 to the curvature. During welding, due to the non-uniform heat input along the weld direction, the component undergoes continuous curvature changes along its length. Currently, evaluation is typically based on single-point displacement or overall deformation, which fails to reflect the cumulative effect of local curvature distribution on overall deformation, making it difficult to accurately quantify bending deformation. This embodiment constructs the relationship between the angle change and initial spacing between adjacent monitoring points, calculates the curvature, and converts it into bending modal strain energy based on the material's bending stiffness, thus achieving an energy-based characterization of bending deformation.

[0018] 2) Torsional modal strain energy calculation: For monitoring points symmetrically arranged laterally along the weld direction (composed of different monitoring sections), the torsional angle per unit length is calculated using the rotation angle about the x-axis (the axis of the metal component; torsional deformation is manifested as the relative rotation of the component about the weld axis, i.e., the x-axis). in, This represents the angle of twist per unit length at time t for the j-th pair of symmetrical monitoring points (each pair consists of a left monitoring point and a right monitoring point, with a total of m pairs of transverse monitoring points), describing the degree of twist about the axis of the metal component. This represents the angle data (i.e., rotation angle) of the j-th pair of left monitoring points around the x-axis at time t. The x-axis is the axis of the component. Assuming the weld is along the x-direction, this rotation angle is the change relative to the initial state. This represents the angle data of the j-th pair of right-side monitoring points around the x-axis at time t (similarly). This indicates the initial lateral distance between the symmetrical monitoring points (measured before welding). Calculation of torsional modal strain energy based on torsion angle: in, It represents the torsional equivalent stiffness, used to characterize a component's ability to resist torsional deformation. It represents the torsional modal strain energy at time t, describing the energy accumulated during torsional deformation of a metal component.

[0019] For torsional equivalent stiffness If the cross-sectional shape of the metal component along the weld direction is regular, such as rectangular or I-shaped: q represents Poisson's ratio, approximately 0.3 for metallic materials, and T represents the torsional constant of the cross-section (a fixed constant in existing technologies). When the cross-sectional shape is irregular, a known torque M2 is applied to the metallic component or a specimen of the same material, and the torsional angle per unit length is measured. The torsional equivalent stiffness is obtained based on the ratio of the known torque M2 to the torsional angle per unit length. Due to asymmetrical heat input distribution or non-uniform component cross-section, torsional deformation around the axis is easily generated. However, existing technologies often struggle to capture the relative rotational relationship between symmetrical points, resulting in the inability to effectively identify and quantify torsional deformation, creating a blind spot in the control process. Here, by selecting symmetrical monitoring point pairs, calculating their angular difference, and combining it with the torsional stiffness parameters of the material, it is converted into torsional modal strain energy, improving the response accuracy.

[0020] To eliminate the influence of overall translation and rotation of the metal component during welding on the measurement of local warping deformation, rigid body registration is performed on the coordinates of all monitoring points at the current moment before calculating the warping modal strain energy (so that the subsequent warping modal strain energy calculation only reflects local out-of-plane instability): Define the real-time coordinates of the current monitoring points. Coordinates of unwelded state monitoring points In a local sub-region R of the monitoring point set (the entire surface of the metal component is divided into several small areas according to spatial location, such as selecting a section at certain intervals along the weld direction, each section containing 2-3 monitoring points on each side of the weld, and each region containing at least nR non-collinear monitoring points, where nR is not less than 4), a rigid body transformation is performed (rigid body elimination uses all monitoring points M, and subsequent warping calculations are performed sequentially on the nR points within each sub-region). , Represents an orthogonal rotation matrix. Represent the translation vector and establish the optimization objective. Eliminate global coordinates after rigid body motion For each local sub-region R, an ideal plane is fitted using the initial coordinates of each monitoring point within it (e.g., k=1,2,...nR), and the ideal plane is fitted using the least squares method. ,coefficient , , The least squares method is used to minimize the sum of squared residuals. This process is a common procedure and will not be elaborated upon in this embodiment. The coordinates of each monitoring point within the sub-region after rigid body elimination are then taken. Calculate out-of-plane displacement , representing the displacement of the k-th monitoring point relative to the fitted ideal plane at time t, with positive values ​​indicating above the ideal plane (convexity) and negative values ​​indicating below the ideal plane (concavity), used to characterize the degree of local warping. Further, the root mean square of the warping displacement is defined. , Used to describe overall warpage strength, and calculated warpage modal strain energy based on warpage equivalent stiffness and root mean square (RMS) values. . The warping equivalent stiffness represents the structure's ability to resist warping deformation. In this embodiment, the curvature and torsional modes are calculated using the rotation angle difference between adjacent monitoring points. Rigid body rotation is approximately the same between adjacent points and can be eliminated after differentiation; therefore, only warping requires separate elimination of rigid body motion. If there are situations, such as the original measurement including rigid body rotation, the calculation of the bending and torsional mode strain energy is based on the global coordinates and derived angle data after eliminating rigid body motion, avoiding misjudging the overall translation or tilt of the component as bending deformation or the overall torsion as local torsional deformation.

[0021] For warp equivalent stiffness For thin metal components with uniform thickness (e.g., less than 6 mm). hr represents the thickness of the metal component. The warping characteristic length dimension is usually taken as the width of a local sub-region. The formula is based on the thin plate elasticity theory and is an approximate expression of the out-of-plane bending stiffness of the plate under local concentrated force. Alternatively, it can be obtained through actual measurement. A local sub-region with the same dimensions as the sub-region mentioned above is selected in the non-welded area of ​​the metal component. A known concentrated force (e.g., 10N, 50N, etc.) is applied using a rigid indenter at the center point of this region. This concentrated force acts only on a small area contacted by the tip of the indenter, not distributed across the entire sub-region; the area of ​​action of the concentrated force can be ignored). The warping displacement at the center point of this region is measured. The ratio of the known concentrated force to the warping displacement yields the equivalent warping stiffness. (If the thickness is uneven, it will lead to asymmetrical local stiffness distribution. The warping displacement field generated under the concentrated force may not be a bulge, but may show tilting or local twisting. Multiple measurements at different locations can be taken and the average value taken.) It is important to note that during the experiment, it should be ensured that only local warping occurs in this region without causing overall bending or torsion. Bending modal strain energy and torsional modal strain energy correspond to deformation continuously distributed along the structural path. Their energy originates from the local contributions of each structural segment or monitoring point pair and needs to be characterized as a whole by accumulating segment by segment. The warping modal strain energy corresponds to the out-of-plane displacement distribution of the monitoring point in the local sub-region relative to the ideal plane. Its essence is the degree of spatial deviation of discrete points. In order to avoid the mutual cancellation of positive and negative displacements and to accurately reflect the overall warping intensity, the root mean square method of squaring, averaging and taking the square root of the out-of-plane displacement is used for characterization.

[0022] By summing the calculated bending modal strain energy, torsional modal strain energy, and warping modal strain energy, a deformation state quantity can be obtained. It is used to describe the overall deformation degree of metal components during the welding process.

[0023] Step S4: Based on the deformation state quantities calculated above By analyzing the input features in the welding process state data S(t), the deformation trend of the metal component at the next moment can be predicted, and the deformation prediction amount can be obtained, specifically: Collect process parameters of the metal components during the welding process, including welding voltage. Welding current and welding speed Define the heat input per unit length Heat input per unit length is used to reflect the energy input per unit length during the welding process; Then, based on the heat input per unit length... and deformation state quantity Establish the deformation prediction of the metal component at the next moment. : in, , These are the corresponding deformation state continuation coefficients (welding deformation has a cumulative effect and inertia: the deformation that has already occurred will change the stiffness distribution and stress state of the component, thus affecting the deformation increment caused by subsequent heat input. Dimensionless, usually between 0 and 1. If it is 0, it means that the deformation has no continuity and is completely determined by the current heat input; if it is close to 1, it means that the deformation will continue to grow) and the equivalent length of heat input (unit: m, which can be understood as the amount of heat input per unit length). (The thermal energy within a length of meters is effectively converted into deformation energy). These two parameters are obtained through experimental calibration, such as setting up monitoring points on the metal component, conducting welding tests, and recording the deformation state in real time. Welding voltage Welding current and welding speed ,calculate A linear regression model can be established from the collected data sets, and then the solution can be obtained based on the least squares method. , Secondly, even without experimental calibration, these two parameters can currently be configured based on the properties of the metal component, such as the stiffness of the metal component, the yield strength of the material, or the welding sequence. scope: Thin plates (component thickness ≤ 6mm), low stiffness (below the preset standard), easily deformable materials (aluminum alloy), strong deformation continuity, and existing deformation will significantly affect subsequent deformation. Medium-thick plates (6-20mm), medium stiffness (normal stiffness standard), and moderate continuity. Thick plates (greater than 20mm) with high stiffness (exceeding the normal stiffness standard) exhibit deformation primarily dependent on current heat input, resulting in a weak cumulative effect. ; for The thermal diffusion characteristics of the component are related to its length, plate thickness, and the range of the heat source. For components with a thickness not exceeding 3 mm, the heat-affected zone is large, but the deformation energy concentration is low. Components with a thickness exceeding 3mm but less than 10mm are classified as medium-thickness plates. When the thickness of a component exceeds 10mm, it is classified as a thick plate, and heat input mainly causes localized deformation. .

[0024] Therefore, after calculating the predicted deformation of the aforementioned metal components... and deformation state quantity Combined with the target deformation threshold Calculate the deviation According to the deviation amount The control quantities for each component are generated, which are divided into welding current adjustment quantity and welding speed adjustment quantity: in, (Unit: A / J) (Units are (mm / s) / J) represent the corresponding control gain coefficients. , These represent the welding current adjustment amount and the welding speed adjustment amount, respectively. The welding voltage is not adjusted independently, but is automatically determined according to the current welding current based on the preset current-voltage characteristic curve. , , These represent the initial welding voltage reference value and welding current reference value (set at the start of welding), respectively. This indicates an empirically preset slope (e.g., 0.02–0.05 V / A; when the controller adjusts the welding current, the welding voltage automatically follows the preset slope to maintain arc stability). From this, the welding current and welding speed for the next moment can be obtained. Output updates to subsequent control parameters , Used for the welding process in the next moment, it changes the subsequently collected welding process status data, realizing automatic monitoring and safety control of welding deformation.

[0025] For control gain coefficient , This can usually be obtained through experimental calibration: Current step experiment: While keeping the welding voltage and welding speed constant, apply a small current step. For example, +10A, to avoid excessive current affecting welding quality, i.e., from the initial welding current... Step increase to Continue welding while maintaining the welding voltage and speed, and observe. After the change stabilizes, the deformation state quantity over a certain period of time is taken. The mean value is used as the deformation state quantity for the restabilization of the welding process. Before the applied current step, the welding process was also in the aforementioned steady state, and the deformation state value was also taken over a certain period of time. The mean value is used as the deformation state quantity before the step is applied. , The difference is obtained. ,but .

[0026] The same principle applies to the velocity step experiment: with constant welding current and welding voltage, a small velocity step (e.g., +1 mm / s) is applied, and subsequent measurements are performed in the same manner as described above. And based on applying a small velocity step and Definition of ratio The step direction should cause a significant change in deformation energy; for example, increasing the current will increase the heat input and thus the deformation energy. It is positive; increasing the speed will reduce the heat input and the deformation energy. When the value is negative, the gain is calculated. Take the absolute value.

[0027] In addition, a real-time monitoring and control system for welding deformation is also provided, including: The data acquisition unit acquires the reference position data of the metal component in the unwelded state, and sets up monitoring points along the weld path to collect displacement data, corresponding angle data, welding voltage, welding current and welding speed. The welding deformation monitoring unit, based on the displacement data and angle data, performs deformation mode decomposition on the metal component, calculates the bending mode strain energy, torsional mode strain energy and warping mode strain energy respectively, and obtains deformation state quantities characterizing the overall deformation degree. The deformation prediction unit constructs a deformation prediction model based on the deformation state quantity and the welding voltage, welding current and welding speed in the welding process state data, and obtains the deformation prediction quantity for the next moment. The welding control unit generates welding current and welding speed adjustments based on the deviation between the predicted deformation and a preset threshold to regulate the welding process. The method described above can be used as described.

[0028] Furthermore, if the aforementioned function is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium 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 the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0029] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-including system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device.

[0030] More specific examples of computer-readable media (a non-exhaustive list) include: electrical connections (electronic devices) having one or more wires, portable computer disk drives (magnetic devices), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Furthermore, computer-readable media can even be paper or other suitable media on which the program can be printed, because the program can be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in computer memory.

[0031] Furthermore, in order to provide a concise description of exemplary embodiments, not all features of actual embodiments (i.e., those features that are not relevant to the best mode of carrying out the invention as currently considered, or those features that are not relevant to implementing the invention) may be omitted.

[0032] It should be understood that numerous specific implementation decisions can be made during the development of any practical implementation, such as in any engineering or design project. Such development efforts may be complex and time-consuming, but for those skilled in the art who benefit from this disclosure, the development effort will be a routine work of design, manufacturing, and production without requiring much experimentation.

[0033] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions will not cause the essence of the corresponding technical solutions to deviate from the protection scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for real-time monitoring and control of welding deformation of metal components, characterized in that, include: Acquire reference position data of metal components in unwelded state, and set up monitoring points along the weld path to collect displacement data and corresponding angle data relative to the reference position data, as well as welding voltage, welding current and welding speed. Based on the displacement and angle data, the deformation modes of the metal component are decomposed, and the bending modal strain energy, torsional modal strain energy, and warping modal strain energy are calculated respectively to obtain deformation state quantities characterizing the overall deformation degree, wherein: The bending modal strain energy is determined by the angle difference between adjacent monitoring points about the axis perpendicular to the weld direction and the spacing to determine the degree of bending, and the bending deformation energy of each structural section is accumulated. Torsional modal strain energy is determined based on the angular difference between each monitoring point and the axis of the component, combined with the lateral distance, to determine the degree of torsion, and to accumulate the torsional deformation energy of each monitoring point pair; The warping modal strain energy is based on the ideal plane fitted by the monitoring points, and the out-of-plane displacement of each monitoring point relative to the ideal plane is calculated to characterize the energy of local warping deformation. Based on the deformation state quantity and the welding voltage, welding current and welding speed in the welding process state data, a deformation prediction model is constructed to obtain the deformation prediction quantity at the next moment. Based on the deviation between the predicted deformation and the preset threshold, welding current adjustment and welding speed adjustment are generated to control the welding process.

2. The method according to claim 1, characterized in that, The displacement data is obtained by comparing the spatial coordinates of each monitoring point at the current moment with its initial coordinates under the reference pose data. Specifically, the coordinate differences in the three spatial directions are calculated to obtain the displacement change of the monitoring point in each direction. The angle data is obtained by comparing the current attitude of each monitoring point with the initial attitude, and is represented as the amount of rotational change in each direction; The displacement data, angle data, welding voltage, welding current, and welding speed of all monitoring points are used to form welding process status data.

3. The method according to claim 1, characterized in that, The method for determining the bending modal strain energy is as follows: Select adjacent monitoring points sequentially along the weld direction, and take the distance between any two adjacent monitoring points as the length of a structural section. For each structural section, calculate the angular difference between the monitoring points at both ends of the section around the axis perpendicular to the weld direction, and use the ratio of this angular difference to the corresponding length of the structural section to obtain the curvature of the section, which reflects the degree of bending. The curvature corresponds to the length of the structural segment, and the bending equivalent stiffness is weighted and summed for all structural segments to obtain the overall bending modal strain energy.

4. The method according to claim 1, characterized in that, The method for determining the torsional modal strain energy is as follows: Select monitoring point pairs that are symmetrically arranged along the transverse direction of the weld, and use the initial transverse distance between each pair of monitoring points as the reference length; For each pair of monitoring points, calculate the angular difference around the axis of the component, and use the ratio of this angular difference to the corresponding initial lateral distance to obtain the torsion angle per unit length. The torsion angle per unit length and the initial lateral distance are used in the calculation, along with the equivalent torsional stiffness. By summing up the results from all monitoring points, the torsional modal strain energy is obtained.

5. The method according to claim 1, characterized in that, The method for determining the warping modal strain energy is as follows: The real-time coordinates of all monitoring points are rigidly registered, minimizing the overall deviation between the coordinates of all monitoring points at the current moment and their initial coordinates under the reference pose data, thus eliminating the effects of overall translation and overall rotation. The metal component is divided into multiple local sub-regions. No less than a preset number of monitoring points are selected in each local sub-region. Based on the initial coordinates of the selected monitoring points under the reference pose data, the ideal plane is obtained by fitting through the principle of minimum error. For each monitoring point within a local sub-region, the current coordinates after rigid body registration are substituted into the ideal plane to calculate the vertical deviation of the monitoring point relative to the ideal plane, which is then used as the out-of-plane displacement. The warping intensity of the local sub-region is obtained by performing root mean square processing on the out-of-plane displacement of all monitoring points within the same local sub-region. The warping modal strain energy is obtained based on the warping strength and the warping equivalent stiffness.

6. The method according to claim 3, characterized in that, The method for determining the bending equivalent stiffness is as follows: If the cross-sectional shape of the metal component along the weld direction is regular: The bending equivalent stiffness is calculated based on the product of the elastic modulus of the metallic component material and the moment of inertia of the cross section about the bending axis, where: For a rectangular cross-section, the moment of inertia is determined based on the width and height of the cross-section. If the cross-sectional shape is irregular: Before welding, a region is selected on the metal component that avoids the weld location. A known bending moment is applied, and the angle difference is measured using monitoring points and the curvature is calculated. The bending equivalent stiffness is calculated based on the ratio of the known bending moment to the curvature.

7. The method according to claim 4, characterized in that, The method for determining the torsional equivalent stiffness is as follows: If the cross-sectional shape of the metal component along the weld direction is regular: calculate the torsional equivalent stiffness based on Poisson's ratio, elastic modulus, and torsional constant of the cross-section; When the cross-sectional shape is irregular, a known torque is applied to a metal component or a specimen of the same material, the angle of torsion per unit length is measured, and the torsional equivalent stiffness is obtained based on the ratio of the known torque to the angle of torsion per unit length.

8. The method according to claim 5, characterized in that, The method for determining the equivalent warpage stiffness is as follows: The metal component is a thin plate with uniform thickness and less than 6 mm. The warping equivalent stiffness is calculated based on the thickness of the metal component, the warping characteristic length dimension, Poisson's ratio and elastic modulus.

9. The method according to claim 5, characterized in that, The method for determining the warping equivalent stiffness also includes: A local sub-region is selected in the non-welded area of ​​the metal component, a known concentrated force is applied, and the warping displacement of the center point of the region is measured. The warping equivalent stiffness is obtained by the ratio of the known concentrated force to the warping displacement.

10. A real-time monitoring and control system for welding deformation, applied to the method described in any one of claims 1-9, characterized in that, include: The data acquisition unit acquires the reference position data of the metal component in the unwelded state, and sets up monitoring points along the weld path to collect displacement data, corresponding angle data, welding voltage, welding current and welding speed. The welding deformation monitoring unit, based on the displacement data and angle data, performs deformation mode decomposition on the metal component, calculates the bending mode strain energy, torsional mode strain energy and warping mode strain energy respectively, and obtains deformation state quantities characterizing the overall deformation degree. The deformation prediction unit constructs a deformation prediction model based on the deformation state quantity and the welding voltage, welding current and welding speed in the welding process state data, and obtains the deformation prediction quantity for the next moment. The welding control unit generates welding current adjustment amount and welding speed adjustment amount to control the welding process based on the deviation between the predicted deformation amount and the preset threshold.

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