Welding spot position layout optimization method for steel pipe welding

Abstract

The invention relates to the technical field of welding control, in particular to a welding spot position layout optimization method for steel pipe welding. According to the method, an active detection experiment is adopted, a group of excitation points and response points are set, a pipeline baseline resonance frequency set and a baseline resonance response amplitude total amount of a current pipeline are determined based on an experiment result, and under each group of preset welding point strategies, each welding point serves as a new excitation point; and determining a response amplitude sequence corresponding to the response point according to the response of the response point, quantizing a preferred index, and screening out welding point redundancy while meeting the pipeline regulation and control effect based on the preferred index. According to the method, the dynamic response characteristic of the steel pipe to welding is determined through the active detection experiment process, the optimal welding point strategy is determined by analyzing the response coupling relation between the welding points, the welding result is verified, and it can be guaranteed that the follow-up construction process is conducted smoothly while the optimal welding strategy is determined.

Description

Technical Field

[0001] This invention relates to the field of welding control technology, and specifically to a method for optimizing the layout of weld points in steel pipe welding. Background Technology

[0002] During their service life, steel pipelines experience internal pressure, temperature fluctuations, and external environmental loads, resulting in a complex, unmeasurable residual stress field within the pipe wall. When repairing local defects in such pipelines by welding, the localized high temperatures and intense thermal gradients introduced during the welding process become a strong disturbance source, disrupting the original stress balance and propagating and redistributing stress waves throughout the pipeline structure. Existing engineering practice has confirmed that this stress redistribution can adversely overlap with pre-existing high-stress zones at the far ends of the pipeline (e.g., near elbows, tees, or supporting structures). When the superimposed stress exceeds the material's critical value, it can induce delayed cracking in non-welded areas, posing a safety hazard.

[0003] To eliminate the aforementioned risks, existing technologies often rely on empirical or simple testing-based field methods. When considering the layout of pre-treated weld points, they frequently perform a simple linear superposition of the effects of multiple pre-treated weld points. This approach ignores a key characteristic of pipelines as continuous structures: the influence of weld points at different locations on the global dynamic response is coupled and not independent. If digital simulation optimization methods are used, they heavily depend on an accurate initial state model, which is not engineering feasible for existing pipelines with unknown historical stress fields. In summary, existing methods for setting welding point strategies do not consider the actual physical characteristics of the steel pipe, ignore the coupled responses between points, and cannot determine a suitable optimal strategy from among numerous welding strategies. Summary of the Invention

[0004] To address the technical problem that existing technologies fail to consider the coupling response between welding points and the actual physical characteristics of steel pipes during the optimization process of multiple preset welding point strategies, the present invention aims to provide a method for optimizing the layout of welding point positions in steel pipe welding. The specific technical solution adopted is as follows: This invention proposes a method for optimizing the layout of weld points in steel pipe welding, the method comprising: Excitation points and response points are set on the outer wall of the pipeline; the first response electrical data of the response point is collected under the simulated welding electrical data input at the excitation point; the set of pipeline baseline resonant frequencies and the total amplitude of the baseline resonant response generated by all pipeline baseline resonant frequencies are obtained based on the simulated welding electrical data and the first response electrical data. Each group of preset welding point strategies includes welding points as new excitation points to obtain second response electrical data of the response points; the response amplitude corresponding to the pipeline baseline resonant frequency is determined from the second response electrical data to obtain a response amplitude sequence; the optimization index is obtained based on the consistency between the response amplitude sequences; the optimal welding point strategy is determined among all preset welding point strategies based on the optimization index. Welding points are set on the pipeline based on the optimal welding point strategy. After welding is completed, the total amplitude of the verification resonance response is obtained based on the excitation point and the response point. The total amplitude of the verification resonance response is compared with the total amplitude of the baseline resonance response to evaluate the welding effect.

[0005] Furthermore, the simulated welding electrical data includes input current, input voltage, input thermal power signal obtained from the input current and input voltage, and self-power spectral density signal obtained by spectral analysis of the input thermal power signal.

[0006] Furthermore, the first response electrical data includes the output voltage signal detected by the sensor at the response point location, and the cross-power spectral density signal between the input thermal power signal and the output voltage signal.

[0007] Furthermore, the method for obtaining the set of resonant frequencies of the pipeline baseline includes: The baseline transfer function is obtained by taking the signal value on the cross power spectral density signal as the numerator and the signal value on the auto-power spectral density signal as the denominator. Peak detection is performed on the baseline transfer function, and the frequency corresponding to the detected peak is the baseline resonance frequency, which constitutes the set of baseline resonance frequencies.

[0008] Furthermore, the method for obtaining the total amplitude of the baseline resonance response includes: The absolute values ​​of the amplitudes corresponding to all the baseline resonant frequencies on the baseline transfer function are summed to obtain the total amplitude of the baseline resonant response.

[0009] Furthermore, the method for obtaining the preference index includes: For each set of preset welding point strategies, the response amplitude sequences of all welding points are combined into a response amplitude matrix. Singular value decomposition is performed on the response amplitude matrix, and the ratio of the maximum singular value to the minimum non-zero singular value is used as the optimization index.

[0010] Furthermore, the method for evaluating the welding effect includes: The total amplitude of the baseline resonance response is attenuated according to a preset safety factor to obtain a resonance response amplitude threshold. If the total amplitude of the verified resonance response is less than the resonance response amplitude threshold, it is judged as a valid weld; if the total amplitude of the verified resonance response is not less than the resonance response amplitude threshold, it is judged as an invalid weld.

[0011] Furthermore, the preset welding point strategy with the smallest optimization index among the preset welding point strategies is selected as the optimal welding point strategy.

[0012] Furthermore, the method for selecting the optimal welding point strategy also includes: All preset welding point strategies are categorized according to the number of welding points; Starting with the category with the fewest welding points, iteratively analyze the categories in order of increasing number of welding points. The preset welding point strategy corresponding to the minimum optimization index within the category is used as the reference strategy within the corresponding category. If the optimization index of the reference strategy is less than or equal to the preset index threshold, the iteration stops; otherwise, analyze the next category until all categories have been analyzed, and then stop the iteration. The reference strategy obtained from the last analysis is taken as the optimal welding point strategy.

[0013] Furthermore, the preset safety factor is set to 0.3, and the product of the preset safety factor and the total amplitude of the baseline resonance response is used as the resonance response amplitude threshold.

[0014] The present invention has the following beneficial effects: To determine the real-time stress response characteristics of the steel pipe to be welded, this invention first employs an active detection experiment, setting a set of excitation and response points. Based on the experimental results, the set of baseline resonant frequencies and the total amplitude of the baseline resonant response are determined. These two features are used to assess the dynamic response characteristics of the current pipeline. Then, under each preset welding point strategy, each welding point is used as a new excitation point. The response amplitude sequence of each response point is determined based on its response. The response amplitude sequences of all welding points reflect the response coupling relationship between them. In an ideal welding strategy, the stress regulation effect of the welding points on the pipeline should be balanced and approximately decoupled, and the overall resonance suppression effect should be insensitive to construction errors. That is, the response amplitude sequences should maintain a certain consistency. Therefore, this invention quantifies an optimization index. Based on this index, welding points that meet the pipeline regulation effect can be selected while avoiding redundant welding points. After determining the optimal welding point strategy, this invention also performs a verification process on the welding results. By comparing the total amplitude of the resonant response with the total amplitude of the baseline resonant response, the quality of the current pipeline welding results can be further evaluated, providing a reference for subsequent construction processes and improving construction efficiency. This invention utilizes an active detection experiment to determine the dynamic response characteristics of steel pipes to welding, analyzes the response coupling relationship between welding points to determine the optimal welding point strategy, and verifies the welding results. This allows for the determination of the optimal welding strategy while ensuring the smooth progress of subsequent construction processes. Attached Figure Description

[0015] To more clearly illustrate the technical solutions and advantages in the embodiments of the present invention 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 the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a flowchart illustrating a method for optimizing the layout of weld points in steel pipe welding, as provided in one embodiment of the present invention. Detailed Implementation

[0017] To further illustrate the technical means and effects adopted by the present invention to achieve its intended purpose, the following, in conjunction with the accompanying drawings and preferred embodiments, details the specific implementation, structure, features, and effects of a method for optimizing the weld point layout of steel pipe welding according to the present invention. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics in one or more embodiments can be combined in any suitable form.

[0018] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0019] The following describes in detail, with reference to the accompanying drawings, a specific scheme for optimizing the weld point layout of steel pipe welding provided by the present invention.

[0020] Please see Figure 1 The diagram illustrates a flowchart of a method for optimizing the weld point layout in steel pipe welding according to an embodiment of the present invention. The method includes: Step S1: Set excitation points and response points on the outer wall of the pipeline; collect the first response electrical data of the response point under the simulated welding electrical data input by the excitation point; obtain the set of pipeline baseline resonant frequencies and the total amplitude of the baseline resonant response generated by all pipeline baseline resonant frequencies based on the simulated welding electrical data and the first response electrical data.

[0021] In order to obtain the real-time dynamic response of the steel pipe to be welded in its current state to welding, an active detection experiment was first conducted before welding. An excitation point and a response point were set on the outer wall of the pipe, wherein the excitation point was used to input a set of simulated welding electrical data into the pipe, and the response point was used to detect the first response electrical data of the response point position to the simulated welding electrical data.

[0022] This set of excitation-response data allows for further analysis. This embodiment of the invention analyzes the relationship between excitation and response in the frequency domain, determines the set of pipeline baseline resonant frequencies, and further quantifies the total amplitude of the baseline resonant response generated by all pipeline baseline resonant frequencies. These two features characterize the current dynamic response characteristics of the pipeline. Each baseline resonant frequency can be considered a resonant mode, while the total amplitude of the baseline resonant response characterizes the overall degree of response of the steel pipe under the current defective state.

[0023] This active detection experiment enables the objective and quantitative acquisition of the dynamic response characteristics of currently in-service pipelines without causing any damage, and allows the extraction of a series of baseline parameters characterizing their resonance modes. These parameters can be applied to subsequent weld point analysis without the analytical errors caused by improper prior model settings in existing technologies.

[0024] In this embodiment of the invention, the excitation point is located near the main defect area to be repaired, i.e., near the area to be welded. The response point can be set according to the pipeline design drawings or existing inspection experience, in the distant structural discontinuity area where historical stress concentration is most likely to exist, such as near the bend or tee joint of the pipeline. At the excitation point location, a programmable welding power supply is deployed. The tungsten electrode of its welding torch maintains a fixed distance from the outer wall of the pipeline, which does not produce arc melting, for example, 3 mm, to ensure that heat is applied to the pipeline non-contactly through plasma. At the response point location, a broadband piezoelectric acoustic emission sensor is tightly attached to the outer wall of the pipeline using an acoustic coupling agent to receive stress wave signals. The current and voltage monitoring signal output terminals of the programmable welding power supply and the signal output terminal of the acoustic emission sensor are both connected to a high-speed data acquisition card with multi-channel synchronous acquisition function. This enables the acquisition and transmission of excitation-response data.

[0025] It should be noted that, since the repair welding itself is a high-energy thermomechanical disturbance with energy distributed over a wide frequency range, in order to comprehensively detect the pipeline's response tendency to disturbances at different frequencies, the input current at the excitation point in this embodiment of the invention should be a weak broadband excitation with controllable energy and a known spectrum. In this embodiment, the input current is set as a linear frequency-sweeping sinusoidal signal, the signal form of which is: ;in, For input current signal, As the DC bias base current, the embodiments of the present invention are set as follows: It is 5A; The amplitude is set to 2A in this embodiment of the invention; is the frequency sweep rate, where , This is the frequency to terminate the sweep. This is the start frequency for the frequency sweep. The total sweep duration is set to 1kHz for the sweep start frequency and 100kHz for the sweep end frequency. The time is represented by ; sin is the sine function. The form of this linear sweep sine signal is well-known to those skilled in the art and will not be elaborated upon here.

[0026] Preferably, in this embodiment of the invention, the simulated welding electrical data includes input current, input voltage, input thermal power signal obtained from the input current and input voltage, and self-power spectral density signal obtained by spectral analysis of the input thermal power signal.

[0027] Both the input current and input voltage can be acquired using a high-speed data acquisition card at a sampling frequency that satisfies the Nyquist sampling theorem (250kHz in this embodiment). The input thermal power signal is the product of the input current signal, the input voltage signal, and the known arc thermal efficiency coefficient under the welding process, expressed by the following formula: ; For input thermal power signal, For input current signal, The input voltage signal. The arc thermal efficiency coefficient is a known prior art data point, which can be obtained by consulting existing literature. This invention does not limit or elaborate on this specific data.

[0028] It should be noted that the self-power spectral density signal is used for subsequent frequency domain analysis, and it represents a smooth and low-noise spectral estimate. In this embodiment of the invention, the Welch average periodogram method can be used to obtain it. In other implementations of this invention, known existing techniques such as the Blackman-Tuki method can also be used for spectral analysis, which will not be elaborated upon or limited here.

[0029] Furthermore, the first response electrical data in this embodiment of the invention includes the output voltage signal detected by the sensor at the response point location, and the cross-power spectral density signal between the input thermal power signal and the output voltage signal.

[0030] Similarly, the output voltage signal can also be obtained by acquiring data from the acoustic emission sensor at the response point location using a high-speed data acquisition card. The cross-power spectral density signal represents the energy of the coherent portion between the output voltage signal and the input thermal power signal at different frequencies. The cross-power spectral density signal can also be obtained using the Welch method, which is a technique well-known to those skilled in the art and will not be elaborated here.

[0031] Preferably, in this embodiment of the invention, after obtaining the self-power spectral density signal and the cross-power spectral density signal, since the dynamic response characteristics of the pipeline are inherent properties and should not change with the specific form of the test signal, the two signals are compared to obtain the baseline transfer function of the current pipeline, specifically including: cross power spectral density signal The signal value on the signal is used as the molecule, and the power spectral density signal is used as the molecule. Using the signal value as the denominator, the baseline transfer function is obtained. That is, the baseline transfer function. It is a complex sequence that varies with frequency, and the absolute value of its amplitude represents the amplification factor of the pipeline system's response to a unit input heat power at frequency f. It should be noted that if there is no corresponding amplitude or the corresponding amplitude is 0 on the power spectral density signal at a certain frequency, the data at that frequency will be left blank when obtaining the baseline transfer function.

[0032] Peak detection is performed on the baseline transfer function, and the frequencies corresponding to the detected peaks are the baseline resonant frequencies, forming the set of baseline resonant frequencies. It should be noted that peak detection is a technique well-known to those skilled in the art and will not be elaborated upon here.

[0033] Furthermore, in this embodiment of the invention, the method for obtaining the total amplitude of the baseline resonant response includes: The absolute values ​​of the amplitudes corresponding to all the baseline resonant frequencies on the baseline transfer function are summed to obtain the total amplitude of the baseline resonant response. The total amplitude of the baseline resonant response represents the current initial resonant response level of the pipeline.

[0034] Step S2: Obtain the second response electrical data of the welding points in each group of preset welding point strategies for the excitation point, determine the response amplitude corresponding to the pipeline baseline resonant frequency in the second response electrical data, and obtain the response amplitude sequence; obtain the optimization index based on the element consistency between the response amplitude sequences; determine the optimal welding point strategy among all preset welding point strategies based on the optimization index.

[0035] Existing technologies, when analyzing welding point strategies, often neglect the coupling effect between control points by simply superimposing the effects of individual points, leading to deviations from the expected final result. This invention considers a layout consisting of multiple pre-processed welding points, where the overall control effect is not a linear sum of the effects of each welding point, but rather a complex, mutually coupled system. Therefore, to construct such a system representing the coupling relationship, this invention re-excites each welding point within each set of preset welding point strategies as a new excitation point, and then statistically analyzes the response data of the response points again as the second response electrical data. Because the steel pipe is a continuous elastic body structure, the stress wave generated by the thermomechanical disturbance applied at any candidate welding point location will propagate along the entire pipe body and may simultaneously excite multiple resonance modes at the distal end. These resonance modes can be characterized by the pipe baseline resonance frequency. Therefore, it is necessary to further obtain the response amplitude corresponding to the pipe baseline resonance frequency using the same method, thereby obtaining the response amplitude sequence of each welding point. The response amplitude sequence of all welding points reflects the response characteristics of the welding points to all resonance modes, thus enabling further decoupling analysis. Because an ideal welding point strategy should be one where welding points are non-redundant and each welding point has balanced stress control, the consistency between the response amplitude sequences should also be greater. Therefore, an optimization index for each preset welding point strategy can be obtained based on this consistency, thereby selecting the optimal welding point strategy.

[0036] It should be noted that, in this embodiment of the invention, all welding point positions included in all preset welding point strategies can be statistically analyzed to form a welding point position set. While ensuring the response point positions remain unchanged, the excitation source ensures that completely consistent excitation is applied to the welding points sequentially and precisely. Therefore, the response amplitude sequence obtained for each welding point can constitute a candidate point-resonance response matrix. The rows of this matrix represent the baseline resonant frequency, the columns represent the welding points, and the element values ​​are the response amplitudes. For each preset welding point strategy, the corresponding welding point positions can be selected from the candidate point-resonance response matrix to form a response amplitude matrix for coupled analysis.

[0037] It should be noted that the method for obtaining the second response electrical data is the same as the method for obtaining the first response electrical data. The response amplitude is also obtained in the same way as the response amplitude in step S1, which is the absolute value of the amplitude at the corresponding frequency on the transfer function. No further details or limitations will be provided.

[0038] Preferably, in this embodiment of the invention, the method for obtaining the preferred index through coupling analysis of the preset welding point strategy includes: For each set of preset welding point strategies, a response amplitude matrix is ​​formed from the response amplitude sequences of all welding points. Singular value decomposition (SVD) is then performed on this matrix, and the ratio of the maximum singular value to the minimum non-zero singular value is used as the optimization index. It should be noted that the ratio of the maximum singular value to the minimum non-zero singular value is the condition number in the SVD algorithm. It measures the "illness" of the linear transformation system represented by the matrix. In SVD, the singular values ​​of a matrix represent its "scaling factor" in different directions. The maximum singular value corresponds to the maximum amplification capability of the matrix in the dominant direction, while the minimum non-zero singular value corresponds to the minimum amplification capability in the weakest direction. Therefore, the condition number reflects the range of variation of the matrix's scaling factor: if the ratio is close to 1, it indicates that the scaling capability is uniform in all directions; if the ratio is much greater than 1, it indicates that the matrix is ​​very sensitive in some directions (strong amplification) and almost unresponsive in other directions (weak amplification).

[0039] Therefore, in this scenario, a low condition number indicates that the control effects between welding points are balanced and approximately decoupled, with no obvious redundancy or dependency. Physically, this layout is insensitive to construction errors (such as small changes in weld point position or strength) because all weld points independently contribute to the resonance suppression effect, resulting in strong overall system robustness.

[0040] If the condition number is high, it indicates that in the current welding point strategy, at least one welding point's control effect can be linearly approximated by the effects of other welding points, meaning there is control redundancy. Physically, this redundancy makes the overall layout highly sensitive to small changes in input parameters—construction errors may be amplified, leading to significant fluctuations in resonance suppression performance. For example, if the effect of one welding point can be almost completely replaced by other welding points, then the error of that welding point will significantly affect the system output.

[0041] Using condition number as a feature in coupling analysis allows for a global assessment of the overall linear correlation of response amplitude sequences, rather than just the similarity between pairs of sequences. This completely eliminates all forms of regulatory redundancy, facilitating the identification of more robust welding point strategies. Choosing a layout with a smaller condition number can improve manufacturing and construction tolerance and reduce quality control costs.

[0042] Therefore, in one embodiment of the present invention, the preset welding point strategy with the smallest preferred index can be directly selected as the optimal welding point strategy from among many preset welding point strategies.

[0043] Preferably, in another specific implementation of the present invention, in order to quickly find an optimal welding point strategy with fewer welding points and higher robustness, an iterative approach is adopted to calculate and evaluate the optimization index starting from the strategy with the fewest welding points. This allows the optimal welding point strategy to be found without having to calculate the optimization index of all strategies. Specifically, this includes: All preset welding point strategies are categorized according to the number of welding points; Starting with the category with the fewest welding points, iteratively analyze the categories in order of increasing number of welding points. The preset welding point strategy corresponding to the minimum optimization index within the category is used as the reference strategy within the corresponding category. If the optimization index of the reference strategy is less than or equal to the preset index threshold, the iteration stops; otherwise, analyze the next category until all categories have been analyzed, and then stop the iteration. The reference strategy obtained from the last analysis is taken as the optimal welding point strategy.

[0044] In this embodiment of the invention, the exponential threshold can be set to 10, meaning that strategies that exceed the exponential threshold are considered unreliable in engineering.

[0045] Step S3: Set welding points on the pipeline based on the optimal welding point strategy. After welding is completed, obtain the total amplitude of the verification resonance response based on the excitation point and response point. Compare the total amplitude of the verification resonance response with the total amplitude of the baseline resonance response to evaluate the welding effect.

[0046] Based on the optimal welding point strategy, welding can be deployed and performed according to the welding point locations specified in the strategy. In this embodiment of the invention, operators or automated welding equipment can weld the welding points in the optimal welding point strategy one by one. Each welding point is an independent welding operation with low heat input. For example, a short weld bead with a length of 15-20 mm and a heat input controlled at 0.5-0.8 kJ / mm is deposited at each designated point. It should be noted that, in the specific welding process of this embodiment of the invention, in order to avoid introducing new and undesirable stress concentrations due to concentrated welding, the deployment method of these welding points includes: arbitrarily selecting one point from all welding points as the starting welding point; determining the next welding point from the remaining welding points as the point with the farthest geodesic distance from the previous set welding point on the pipe surface; if there are multiple farthest points, randomly selecting one as the next set welding point; repeating this process until all points are welded.

[0047] After welding is completed and the pipeline structure has been allowed to cool completely to ambient temperature, this embodiment of the invention further performs a verification process. This verification process is used to determine whether the current welding process can effectively control the pipeline stress. Based on the method for obtaining the total amplitude of the baseline resonance response in S1, the excitation experiment is repeated at the same excitation and response points to obtain the total amplitude of the verification resonance response. Comparing the total amplitude of the verification resonance response with the total amplitude of the baseline resonance response, if it is significantly reduced, it indicates that the welding quality is good and the welding process has successfully and effectively suppressed the original resonance mode of the pipeline. From the perspective of stress wave propagation, this means that the pre-treated weld point, acting as a "stress nail," effectively changes the local stiffness distribution of the pipeline, thereby changing the global dynamic response characteristics. This makes the pipeline structure "insensitive" to energy input at the baseline resonance frequency set, making it difficult to excite these resonance modes when broadband energy is introduced in the subsequent main repair weld. At this point, it can be determined that the risk of far-end cracking during the main repair weld construction has been effectively controlled, and it is safe to proceed to the conventional repair welding process for the main defect. Conversely, if no significant reduction is observed, it indicates that the pretreatment has not met the preset engineering safety requirements. In this case, the main repair welding should be suspended, and the pretreatment plan should be reviewed or adjusted.

[0048] Preferably, in this embodiment of the invention, the method for evaluating the welding effect includes: The total amplitude of the baseline resonance response is attenuated according to a preset safety factor to obtain a resonance response amplitude threshold. If the total amplitude of the verified resonance response is less than the resonance response amplitude threshold, it is judged as a valid weld; if the total amplitude of the verified resonance response is not less than the resonance response amplitude threshold, it is judged as an invalid weld.

[0049] In this embodiment of the invention, a preset safety factor is set to 0.3, and the product of the preset safety factor and the total baseline resonance response amplitude is used as the resonance response amplitude threshold. That is, it is considered that the total verification resonance response amplitude must be reduced to at least 70% of the total baseline resonance response amplitude for the welding to be considered valid, and the next step of the process can be performed.

[0050] In summary, this invention first employs an active detection experiment, setting a set of excitation and response points. Based on the experimental results, the set of pipeline baseline resonant frequencies and the total amplitude of the baseline resonant response are determined. Under each preset welding point strategy, each welding point is used as a new excitation point. The corresponding response amplitude sequence is determined based on the response of each response point, and an optimization index is quantified. Based on the optimization index, welding points that meet the pipeline control requirements can be selected while avoiding redundancy. This invention utilizes the active detection experiment process to determine the dynamic response characteristics of the steel pipe to welding, analyzes the response coupling relationship between welding points to determine the optimal welding point strategy, and verifies the welding results. This ensures the smooth progress of subsequent construction processes while determining the optimal welding strategy.

[0051] It should be noted that the order of the above embodiments of the present invention is merely for descriptive purposes and does not represent the superiority or inferiority of the embodiments. The processes depicted in the accompanying drawings do not necessarily require a specific or sequential order to achieve the desired result. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0052] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

Claims

1. A method for optimizing the layout of weld points in steel pipe welding, characterized in that, The method includes: Excitation points and response points are set on the outer wall of the pipeline; the first response electrical data of the response point is collected under the simulated welding electrical data input at the excitation point; the set of pipeline baseline resonant frequencies and the total amplitude of the baseline resonant response generated by all pipeline baseline resonant frequencies are obtained based on the simulated welding electrical data and the first response electrical data. Each group of preset welding point strategies includes welding points as new excitation points to obtain second response electrical data of the response points; the response amplitude corresponding to the pipeline baseline resonant frequency is determined from the second response electrical data to obtain a response amplitude sequence; the optimization index is obtained based on the consistency between the response amplitude sequences; the optimal welding point strategy is determined among all preset welding point strategies based on the optimization index. Welding points are set on the pipeline based on the optimal welding point strategy. After welding is completed, the total amplitude of the verification resonance response is obtained based on the excitation point and the response point. The total amplitude of the verification resonance response is compared with the total amplitude of the baseline resonance response to evaluate the welding effect.

2. The method for optimizing the layout of weld points in steel pipe welding according to claim 1, characterized in that, The simulated welding electrical data includes input current, input voltage, input thermal power signal obtained from the input current and input voltage, and self-power spectral density signal obtained by spectral analysis of the input thermal power signal.

3. The method for optimizing the layout of weld points in steel pipe welding according to claim 2, characterized in that, The first response electrical data includes the output voltage signal detected by the sensor at the response point location, and the cross-power spectral density signal between the input thermal power signal and the output voltage signal.

4. The method for optimizing the layout of weld points in steel pipe welding according to claim 3, characterized in that, The method for obtaining the set of resonant frequencies of the pipeline baseline includes: The baseline transfer function is obtained by taking the signal value on the cross power spectral density signal as the numerator and the signal value on the auto-power spectral density signal as the denominator. Peak detection is performed on the baseline transfer function, and the frequency corresponding to the detected peak is the baseline resonance frequency, which constitutes the set of baseline resonance frequencies.

5. The method for optimizing the layout of weld points in steel pipe welding according to claim 4, characterized in that, The method for obtaining the total amplitude of the baseline resonance response includes: The absolute values ​​of the amplitudes corresponding to all the baseline resonant frequencies on the baseline transfer function are summed to obtain the total amplitude of the baseline resonant response.

6. The method for optimizing the layout of weld points in steel pipe welding according to claim 1, characterized in that, The method for obtaining the preferred index includes: For each set of preset welding point strategies, the response amplitude sequences of all welding points are combined into a response amplitude matrix. Singular value decomposition is performed on the response amplitude matrix, and the ratio of the maximum singular value to the minimum non-zero singular value is used as the optimization index.

7. The method for optimizing the layout of weld points in steel pipe welding according to claim 1, characterized in that, The method for evaluating welding effectiveness includes: The total amplitude of the baseline resonance response is attenuated according to a preset safety factor to obtain a resonance response amplitude threshold. If the total amplitude of the verified resonance response is less than the resonance response amplitude threshold, it is judged as a valid weld; if the total amplitude of the verified resonance response is not less than the resonance response amplitude threshold, it is judged as an invalid weld.

8. The method for optimizing the layout of weld points in steel pipe welding according to claim 6, characterized in that, The preset welding point strategy with the smallest optimization index among the preset welding point strategies is selected as the optimal welding point strategy.

9. The method for optimizing the layout of weld points in steel pipe welding according to claim 6, characterized in that, The method for selecting the optimal welding point strategy also includes: All preset welding point strategies are categorized according to the number of welding points; Starting with the category with the fewest welding points, iteratively analyze the categories in order of increasing number of welding points. The preset welding point strategy corresponding to the minimum optimization index within the category is used as the reference strategy within the corresponding category. If the optimization index of the reference strategy is less than or equal to the preset index threshold, the iteration stops; otherwise, analyze the next category until all categories have been analyzed, and then stop the iteration. The reference strategy obtained from the last analysis is taken as the optimal welding point strategy.

10. The method for optimizing the layout of weld points in steel pipe welding according to claim 1, characterized in that, The preset safety factor is set to 0.3, and the product of the preset safety factor and the total amplitude of the baseline resonance response is used as the resonance response amplitude threshold.

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