Multi-mode heat input coordinated control equipment for argon arc welding machines based on sheet metal processing

Abstract

The present application relates to the field of intelligent welding technology, and specifically to a multi-mode heat input coordinated control device for an argon arc welding machine based on sheet metal processing. The device includes: a sheet metal welding quality assessment module: obtaining a welding quality score for each sheet metal; a welding heat input range limitation module: dividing all positions of the same thickness in a sheet metal into one category, and determining the appropriate heat input range corresponding to each working mode in each category; a welding heat input optimization module: constructing an objective function based on the heat input difference between adjacent welding positions of the current sheet metal, and determining the optimal heat input for each welding position under each working mode during the current sheet metal welding; a welding arc voltage control module: determining the welding speed characteristic factor for each position in each category and the interference coefficient for each working mode in each category; obtaining the control coefficient for each working mode, and real-time controlling the arc voltage at each moment under each working mode during the current sheet metal welding. The present application improves the welding quality of sheet metal parts.

Description

Technical Field

[0001] The present application relates to the field of intelligent welding technology, and specifically to a multi-mode heat input coordinated control device for an argon arc welding machine based on sheet metal processing. Background Art

[0002] Argon arc welding machines are a common type of welding equipment. They primarily utilize argon as a shielding gas and a tungsten electrode to generate an arc. The high temperature of the arc heats and melts the metal workpiece, ultimately completing the weld. Argon arc welding machines offer smooth welding results and beautiful welds, making them particularly suitable for high-quality, high-precision welding. Sheet metal processing often requires joining dissimilar metal sheets through welding, and argon arc welding machines are often used for this purpose due to their precise control and excellent welding performance.

[0003] Traditional argon arc welding machines utilize a single heat input mode for sheet metal welding, making it difficult to balance deformation control for thin plate welding with the required penetration depth for thick plate welding. Excessive heat input can lead to metal grain coarsening, embrittlement of the heat-affected zone, and workpiece deformation; while too low a heat input can result in insufficient penetration, lack of fusion, or insufficient weld strength. Furthermore, while existing equipment can adjust heat input through independent parameters such as current and voltage, it lacks a dynamic coordination mechanism for parameters such as welding speed and arc voltage, resulting in unstable welding quality. Summary of the Invention

[0004] In order to solve the above technical problems, the present application provides a multi-mode heat input coordinated control device for an argon arc welding machine based on sheet metal processing to solve the existing problems.

[0005] The multi-mode heat input coordinated control device of the argon arc welding machine based on sheet metal processing in this application adopts the following technical solutions:

[0006] One embodiment of the present application provides a multi-mode heat input coordinated control device for an argon arc welding machine based on sheet metal processing, the device comprising:

[0007] Sheet metal welding quality assessment module: obtains each sheet metal part welded by the argon arc welding machine in history, evaluates the welding quality of each sheet metal part, and obtains the welding quality score of each sheet metal part;

[0008] Welding heat input range limitation module: All locations of the same thickness in sheet metal parts are divided into one category. Based on the welding quality score of the sheet metal parts corresponding to each location in each category, each reference location in each category is determined. The working mode of the sheet metal parts during welding corresponding to each reference location in each category, as well as the heat input of the sheet metal parts, is used to determine the appropriate heat input range for each working mode in each category.

[0009] Welding heat input optimization module: Before welding the current sheet metal part, the heat input optimum range is used as the heat input value range for each welding position of the current sheet metal part. The heat input difference between adjacent welding positions of the current sheet metal part is combined with the corresponding heat input optimum range to construct an objective function. The optimization algorithm is used to determine the optimal heat input for each welding position under each working mode when welding the current sheet metal part.

[0010] Welding arc voltage control module: Analyzes the distribution of welding speed at each position in each category and determines the welding speed characteristic factor at each position in each category; determines the interference coefficient of each working mode in each category based on the relationship between the welding quality score of the sheet metal parts at each position in each category and the change of the welding speed characteristic factor;

[0011] The control coefficient of each working mode is determined by combining the interference coefficient of all classes under each working mode with the change rate of the change relationship. Based on the optimal heat input, the welding speed at each moment under each working mode during the current sheet metal welding is determined. Combined with the control coefficient and the arc voltage at each moment during the current sheet metal welding, the arc voltage at the next moment under each working mode during the current sheet metal welding is controlled.

[0012] In one embodiment, the reference features for evaluating the welding quality of each sheet metal part include the weld formation coefficient, dimensional accuracy, and welding uniformity of the sheet metal part; and the value range of the welding quality score is [0, 1].

[0013] In one embodiment, the reference position is a position corresponding to a welding quality score of each type of sheet metal part being greater than a preset threshold.

[0014] In one embodiment, determining the appropriate heat input range corresponding to each operating mode in each category includes:

[0015] The working modes during sheet metal welding include direct current mode and pulse mode. The minimum and maximum values ​​of the heat input of the sheet metal corresponding to all reference positions belonging to the direct current mode in each category are obtained, and the numerical range formed by the minimum and maximum values ​​is used as the appropriate heat input range corresponding to the direct current mode in each category.

[0016] Accordingly, the suitable heat input range corresponding to each type of pulse mode is obtained.

[0017] In one embodiment, the objective function is expressed as:

[0018] ; Where f is the objective function, is the difference in heat input between the i-th position and the i+1-th position during the welding of the current sheet metal part. is the difference between the heat input at the i-th position during the welding of the current sheet metal and the middle value of the corresponding heat input suitable range, and D is the number of welding positions of the current sheet metal.

[0019] In one embodiment, the welding speed characteristic factor is the product of the inverse of the discrete degree of the welding speed of the sheet metal parts corresponding to each position in each category during welding and the average level.

[0020] In one embodiment, determining the interference coefficient of each operating mode in each category includes:

[0021] For each working mode in each category, the welding speed characteristic factor at each position is used as the horizontal coordinate, and the welding quality score of the sheet metal parts at each position is used as the vertical coordinate. The fitting curve of the welding quality score of the sheet metal parts at all positions under each working mode in each category with respect to the welding speed characteristic factor is obtained.

[0022] The difference between the welding quality scores of each welding position on the fitting curve and its adjacent previous position is calculated and recorded as the first difference. The ratio of the sum of all the first differences corresponding to the fitting curve to the sum of the absolute values ​​of all the first differences is calculated as the interference coefficient of the working mode corresponding to the fitting curve in each category.

[0023] In one embodiment, determining the control coefficient of each working mode includes:

[0024] Calculate the mean of the slopes of all welding positions on the fitting curve, calculate the product of the mean and the interference coefficient of the working mode corresponding to the fitting curve in each category, record it as the first product, and take the mean of the first product in all categories under each working mode as the control coefficient of each working mode.

[0025] In one embodiment, determining the welding speed at each moment in each working mode during the current sheet metal welding includes:

[0026] The calculation formula of welding heat input is used, and the optimal heat input of each welding position under each working mode during the current sheet metal welding is taken as a known quantity. Combined with the arc voltage and current at each welding position at the corresponding moment during welding, the welding speed at each moment under each working mode during the current sheet metal welding is obtained.

[0027] In one embodiment, the step of adjusting the arc voltage at the next moment in each working mode during the current sheet metal welding includes:

[0028] Calculate the product of the welding speed at each moment in each working mode during the current sheet metal welding and the control coefficient of each working mode, and record it as the second product. The sum of the arc voltage at each moment in each working mode during the current sheet metal welding and the second product is used as the arc voltage at the next moment in each working mode during the current sheet metal welding.

[0029] This application has at least the following beneficial effects:

[0030] This application obtains each sheet metal part that has been welded by an argon arc welding machine in the past, and evaluates the welding quality of each sheet metal part to obtain a welding quality score for each sheet metal part; the determination of the welding quality score quantifies the welding quality of the sheet metal part, thereby improving the convenience of evaluating the welding quality of the sheet metal part; all positions of the same thickness in the sheet metal part are divided into one category, and based on the welding quality score of the sheet metal part corresponding to each position in each category, each reference position in each category is determined; using the working mode of the sheet metal part welding process corresponding to each reference position in each category, as well as the heat input of the sheet metal part, the appropriate heat input range corresponding to each working mode in each category is determined, and the heat input range of the sheet metal part is provided. The accuracy of heat input parameter adaptation is improved. Based on the welding mode and heat input data of the reference position of the same thickness, a dynamic heat input suitable range is established, which avoids insufficient penetration or burn-through defects caused by parameter deviation in traditional processes and solves the heat input mismatch problem caused by local thickness mutation. Before welding the current sheet metal part, the heat input suitable range is used as the value range of heat input of each welding position of the current sheet metal part. Through the heat input difference of adjacent welding positions of the current sheet metal part, combined with the corresponding heat input suitable range, an objective function is constructed, and the optimization algorithm is used to determine the heat input of each welding position under each working mode when welding the current sheet metal part. The optimal heat input of the position is set, which improves the accuracy and reliability of heat input determination in the sheet metal welding process and enhances the adaptability of heat input parameter determination in different scenarios; the distribution of welding speed at each position in each category during welding is analyzed, and the welding speed characteristic factor of each position in each category is determined. The quantitative analysis of the welding speed characteristic factor realizes the quantitative evaluation of the stability and efficiency of the welding process and avoids the insufficient adaptability of the traditional fixed speed strategy in variable working conditions; based on the relationship between the welding quality score of the sheet metal corresponding to each position in each category and each working mode and the change of the welding speed characteristic factor, the interference coefficient of each working mode in each category is determined; The control coefficient of each working mode is determined by combining the interference coefficient of all classes under each working mode with the change rate of the change relationship; based on the optimal heat input, the welding speed at each moment under each working mode during the current sheet metal welding is determined, and the arc voltage at each moment under each working mode during the current sheet metal welding is controlled in combination with the control coefficient and the arc voltage at each moment during the current sheet metal welding. The present application maintains the stability of the thermodynamic state of the molten pool through multi-parameter coupled closed-loop control, avoids the lag of single-parameter feedback control through collaborative control, improves the stability of sheet metal welding, and improves welding quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions and advantages of the embodiments of the present application or the prior art, the following is a brief introduction to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0032] Figure 1 A block diagram of a multi-mode heat input coordinated control device for an argon arc welding machine based on sheet metal processing provided in this application;

[0033] Figure 2 This is a flow chart for adjusting the welding arc voltage. DETAILED DESCRIPTION

[0034] In order to further illustrate the technical means and effects adopted by this application to achieve the predetermined invention purpose, the following, in combination with the accompanying drawings and preferred embodiments, describes in detail the specific implementation method, structure, features and effects of the multi-mode heat input coordinated control device of the argon arc welding machine based on sheet metal processing proposed in this application. In the following description, different "one embodiment" or "another embodiment" does not necessarily refer to the same embodiment. In addition, specific features, structures or characteristics in one or more embodiments may be combined in any suitable form.

[0035] Unless defined otherwise, 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 application belongs.

[0036] The specific scheme of the multi-mode heat input coordinated control equipment of the argon arc welding machine based on sheet metal processing provided by this application is described in detail below with reference to the accompanying drawings.

[0037] An embodiment of the present application provides a multi-mode heat input coordinated control device for an argon arc welding machine based on sheet metal processing. Specifically, the following block diagram of the multi-mode heat input coordinated control device for an argon arc welding machine based on sheet metal processing is provided. Figure 1 The equipment includes: sheet metal welding quality assessment module, welding heat input range limitation module, welding heat input optimization module, and welding arc voltage control module.

[0038] S1, sheet metal welding quality assessment module: obtains each sheet metal part welded by the argon arc welding machine in the past, evaluates the welding quality of each sheet metal part, and obtains the welding quality score of each sheet metal part.

[0039] Common argon arc welding machines typically include multiple operating modes. Since DC mode and pulse mode are the main operating modes for continuous welding processes, the operating modes of the argon arc welding machine analyzed in this embodiment include DC mode and pulse mode. The DC mode is based on the DC positive polarity connection method, with argon as the shielding gas. It melts the base material and filler wire through stable arc heating to form a continuous weld. The current is always constant, and the arc is highly stable, making it suitable for conventional thick plate welding. The pulse mode, based on DC argon arc welding, controls the formation of the molten pool by periodically switching the base current and peak current, forming a point-like superimposed weld.

[0040] When welding sheet metal parts of varying thicknesses, excessive heat input can lead to metal grain coarsening, embrittlement of the heat-affected zone, and workpiece deformation; while insufficient heat input can result in insufficient penetration, lack of fusion, or insufficient weld strength. To cope with sheet metal parts of varying thicknesses under varying working conditions, the heat input during welding must be properly controlled.

[0041] In this embodiment, any argon arc welder A is taken as an example. The sheet metal parts historically welded by the argon arc welder A are obtained and recorded as historical sheet metal parts. The weld seam forming coefficient, dimensional accuracy, presence of defects, and welding uniformity of each historical sheet metal part are comprehensively considered as reference factors. The welding quality of each historical sheet metal part is manually scored to determine the welding quality score of each historical sheet metal part. The welding quality score ranges from [0, 1]. The larger the welding quality score, the higher the welding quality of the historical sheet metal part.

[0042] S2, welding heat input range limitation module: All positions of the same thickness in the sheet metal parts are divided into one category, and based on the welding quality score of the sheet metal parts corresponding to each position in each category, each reference position in each category is determined; using the working mode of the sheet metal parts in the welding process corresponding to each reference position in each category, as well as the heat input of the sheet metal parts, the appropriate heat input range corresponding to each working mode in each category is determined.

[0043] For all historical sheet metal parts of the argon arc welding machine, positions with the same thickness are grouped together. For example, if there are historical sheet metal parts B1, B2, B3, and B4, and sheet metal part B1 has thicknesses b11, b12, and b13, sheet metal part B2 has thicknesses b21, b22, and b23, sheet metal part B3 has thicknesses b31, b32, and b33, and sheet metal part B4 has thicknesses b41, b42, and b43, where b11 = b22 = b33, then positions corresponding to b11, b22, and b33 are grouped together. If no positions have the same thickness, positions corresponding to a single thickness are grouped together.

[0044] It should be noted that the interval thickness of the sheet metal described in this embodiment is an interval range, for example, (0, 1mm] is a thickness, (1mm, 2mm] is a thickness, (2mm, 3mm] is a thickness, etc. One thickness corresponds to a position of the sheet metal.

[0045] Obtain the welding quality scores of the historical sheet metal parts corresponding to all positions in each category. If the welding quality score is greater than a preset threshold, the corresponding position is used as the reference position in each category. In this embodiment, the preset threshold is set to 0.9, and the implementer can set it according to actual circumstances. This embodiment does not impose any restrictions here.

[0046] For all reference positions in each category, the working modes corresponding to all reference positions in the sheet metal welding process are obtained, namely DC mode and pulse mode, and all reference positions of the same working mode in each category are divided into one group. Since the welding working modes analyzed in this embodiment include DC mode and pulse mode, all reference positions in each category are divided into two groups, one group is the reference positions belonging to the DC mode, and the other group is the reference positions belonging to the pulse mode.

[0047] It should be noted that if there is a reference position that does not belong to the DC mode or the pulse mode among all the reference positions in each category, it will not be grouped.

[0048] For all reference positions belonging to the DC mode in each category, the maximum and minimum values ​​of the heat input of the sheet metal corresponding to the reference position are obtained, and the numerical interval formed by the minimum and maximum values ​​is used as the suitable heat input interval corresponding to the DC mode in each category.

[0049] For all reference positions belonging to the pulse mode in each category, the maximum and minimum values ​​of the heat input of the sheet metal corresponding to the reference position are obtained, and the numerical interval formed by the minimum and maximum values ​​is used as the suitable heat input interval corresponding to the pulse mode in each category.

[0050] It should be noted that the calculation method of welding heat input is the existing well-known technology, and the specific expression is: ; Where Q is the welding heat input, is the thermal efficiency. For argon arc welding, the thermal efficiency is generally taken as 0.6~0.8, I is the welding current, U is the arc voltage, and v is the welding speed.

[0051] S3, welding heat input optimization module: before welding the current sheet metal part, the heat input suitable range is used as the value range of the heat input of each welding position of the current sheet metal part. The heat input difference between adjacent welding positions of the current sheet metal part is combined with the corresponding heat input suitable range to construct an objective function, and the optimization algorithm is used to determine the optimal heat input of each welding position under each working mode when welding the current sheet metal part.

[0052] Since the size of welding heat input directly affects the welding quality of sheet metal parts, this embodiment refers to the welding heat input of historical sheet metal parts to determine the optimal heat input of the current sheet metal part during welding, specifically:

[0053] Before welding the current sheet metal part, optimize the heat input of each welding position during the welding of the current sheet metal part. Use the heat input of each welding position during the welding of the current sheet metal part as the optimization variable to construct the objective function. The expression is:

[0054] ; Where f is the objective function, is the difference in heat input between the i-th position and the i+1-th position during the welding of the current sheet metal part. is the difference between the heat input at the i-th position during the welding of the current sheet metal and the middle value of the corresponding heat input suitable range, and D is the number of welding positions of the current sheet metal.

[0055] This embodiment utilizes a particle swarm optimization algorithm to solve the objective function and obtain the optimal heat input for each welding position on the current sheet metal part. The number of particles is set to 40, and the range of each particle dimension is the optimal heat input range corresponding to the thickness at the corresponding position in historical sheet metal parts. The number of particle dimensions is equal to the number of welding positions on the current sheet metal part. It should be understood that each welding position on the current sheet metal part corresponds to a thickness, and a class of the same thickness exists in historical sheet metal parts. Both operating modes within this class correspond to an optimal heat input range. In this embodiment, the individual learning factor of the particle swarm optimization algorithm is set to 1.5, the social learning factor is set to 2.0, and the maximum number of iterations is set to 30. These can be set by the implementer according to their specific circumstances and are not limited in this embodiment. The particle swarm optimization algorithm minimizes the objective function to obtain the optimal solution. The particle swarm optimization algorithm is a well-known technique, and the specific process is not described in detail here. The implementer can choose other feasible optimization algorithms and are not limited in this embodiment.

[0056] It should be noted that since there will be suitable heat input ranges for two working modes at each thickness position of the current sheet metal part in the corresponding class of historical sheet metal parts, this embodiment can obtain the optimal heat input for each welding position under the two working modes when welding the current sheet metal part.

[0057] S4, welding arc voltage control module: (1) Analyze the distribution of welding speed at each position in each category during welding, and determine the welding speed characteristic factor at each position in each category; determine the interference coefficient of each working mode in each category based on the relationship between the welding quality score of the sheet metal parts at each position in each category and the change of the welding speed characteristic factor.

[0058] Since the magnitude of heat input is positively correlated with voltage and current and negatively correlated with welding speed; when the welding working mode is in DC mode, the current is usually kept constant according to the equipment parameters of the argon arc welding machine. At this time, the heat input can be adjusted by adjusting the welding speed; specifically, according to the above steps, the optimal heat input for each welding position of the current sheet metal is known, so the welding speed can be directly converted.

[0059] When welding in pulse mode, the welding current is constantly changing. When calculating heat input, this embodiment converts the constantly changing welding current (i.e., dynamic current) into a static current. The static current is a constant current. The specific static current conversion method is: Static Current = Base Current × Base Duty Cycle + Peak Current × Peak Duty Cycle. In this case, the welding speed in pulse mode can be calculated based on the welding speed conversion method used in DC mode.

[0060] During the welding process of sheet metal parts, if the arc voltage remains constant as the welding speed increases, the arc length may be "stretched" or "compressed", resulting in incomplete fusion and a decrease in welding quality. Therefore, it is necessary to coordinate the welding speed and voltage.

[0061] It should be understood that the arc voltage and arc length have an approximately linear relationship. When the welding speed increases, the arc voltage needs to increase slightly synchronously to keep the arc length stable.

[0062] Therefore, this embodiment also performs analysis based on the historical classification of sheet metal parts, calculates the discrete degree and average level of the welding speed corresponding to the historical sheet metal parts at each position in each category, and multiplies the inverse of the discrete degree by the average level as the welding speed characteristic factor for each position in each category.

[0063] It should be noted that in this embodiment, the sampling time interval of the welding speed during the historical sheet metal welding is 0.1s, and the calculation method of the discrete degree is variance. The implementer can set the sampling time interval and the calculation method of the discrete degree according to the actual situation. For example, the discrete degree can be calculated using standard deviation, coefficient of variation, etc., and this embodiment does not limit this.

[0064] Furthermore, for each operating mode within each category, the welding speed characteristic factor at each position is used as the horizontal coordinate, and the welding quality score of the sheet metal part corresponding to each position is used as the vertical coordinate. The least squares method is used to perform curve fitting for all positions corresponding to each operating mode within each category, thereby obtaining a fitting curve of the welding quality score of the sheet metal part corresponding to each position within each category and each operating mode with respect to the welding speed characteristic factor. The least squares method is a well-known technique, and implementers may select other feasible fitting algorithms at their discretion, and this embodiment does not limit this.

[0065] For each working mode in each category, the difference between the welding quality scores of each welding position and its adjacent previous position on the fitting curve is calculated, recorded as the first difference, and the ratio of the sum of all the first differences corresponding to the fitting curve to the sum of the absolute values ​​of all the first differences is calculated as the interference coefficient of the working mode corresponding to the fitting curve in each category, that is, the interference coefficient of each working mode in each category.

[0066] It should be understood that the interference coefficient has a value range of [-1, 1]. The closer the value is to -1, the more realistic the theoretical relationship between the welding quality of the sheet metal and the welding speed is, and the higher the credibility of the obtained interference coefficient.

[0067] (2) The control coefficient of each working mode is determined by combining the interference coefficient of all classes under each working mode with the change rate of the change relationship. The welding speed at each moment under each working mode during the current sheet metal welding is determined based on the optimal heat input. The arc voltage at the next moment under each working mode during the current sheet metal welding is controlled by combining the control coefficient with the arc voltage at each moment during the current sheet metal welding.

[0068] For each working mode in each category, the mean of the slopes of all welding positions on the fitting curve is calculated, and the product of the mean and the interference coefficient of the working mode corresponding to the fitting curve in each category is calculated, which is recorded as the first product. For all categories divided by all thickness positions on historical sheet metal parts, the mean of the first products in all categories under each working mode during the historical welding of sheet metal parts is used as the control coefficient of each working mode.

[0069] When welding the current sheet metal part, since the optimal heat input for each welding position of the current sheet metal part has been obtained in advance, the optimal heat input for each welding position under each operating mode during the welding of the current sheet metal part is used as a known quantity using the calculation formula for welding heat input. Combined with the arc voltage and current at the corresponding moment of each welding position during welding, the welding speed at each moment in each operating mode during the welding of the current sheet metal part is obtained. In this embodiment, the arc voltage of the argon arc welder is set to 12V at the initial moment when welding the current sheet metal part. The implementer can set it according to actual conditions, and this embodiment does not impose any restrictions on this.

[0070] Furthermore, according to the relationship between arc voltage and welding speed, combined with the control coefficients of each working mode of the argon arc welding machine, the arc voltage of the argon arc welding machine is adjusted in real time, specifically:

[0071] Calculate the product of the welding speed at each moment in each working mode during the current sheet metal welding and the control coefficient of each working mode, record it as the second product, and use the sum of the arc voltage at each moment in each working mode during the current sheet metal welding and the second product as the arc voltage at the next moment in each working mode during the current sheet metal welding, so as to complete the real-time adjustment of the arc voltage during sheet metal welding, thereby improving the welding quality of sheet metal parts. The welding arc voltage adjustment flow chart is as follows: Figure 2 shown.

[0072] It should be noted that since this embodiment analyzes the two working modes of the argon arc welding machine and can complete real-time adjustment of the arc voltage in both working modes, the implementer can choose the working mode of the argon arc welding machine according to actual conditions in actual operation, and this embodiment does not impose any restrictions here.

[0073] It should be noted that the order in which the embodiments of the present application are presented is for illustrative purposes only and does not necessarily represent the superiority or inferiority of the embodiments. Furthermore, the foregoing descriptions of specific embodiments of this specification are provided. Furthermore, the processes depicted in the accompanying drawings do not necessarily require the specific order or sequential sequence shown to achieve the desired results. In certain embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0074] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on the differences from other embodiments.

[0075] The above-described embodiments are only used to illustrate the technical solutions of the present application, and not to limit them. Modifications to the technical solutions described in the aforementioned embodiments, or equivalent replacements of some of the technical features therein, do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application, and should all be included in the scope of protection of the present application.

Claims

1. A multi-mode heat input coordinated control device for argon arc welding machines based on sheet metal processing, characterized in that: The device includes: Sheet metal welding quality assessment module: obtains each sheet metal part welded by the argon arc welding machine in history, evaluates the welding quality of each sheet metal part, and obtains the welding quality score of each sheet metal part; Welding heat input range limitation module: All locations of the same thickness in sheet metal parts are divided into one category. Based on the welding quality score of the sheet metal parts corresponding to each location in each category, each reference location in each category is determined. The working mode of the sheet metal parts during welding corresponding to each reference location in each category, as well as the heat input of the sheet metal parts, is used to determine the appropriate heat input range for each working mode in each category. Welding heat input optimization module: Before welding the current sheet metal part, the heat input optimum range is used as the heat input value range for each welding position of the current sheet metal part. The heat input difference between adjacent welding positions of the current sheet metal part is combined with the corresponding heat input optimum range to construct an objective function. The optimization algorithm is used to determine the optimal heat input for each welding position under each working mode when welding the current sheet metal part. Welding arc voltage control module: Analyzes the distribution of welding speed at each position in each category and determines the welding speed characteristic factor at each position in each category; determines the interference coefficient of each working mode in each category based on the relationship between the welding quality score of the sheet metal parts at each position in each category and the change of the welding speed characteristic factor; The control coefficient of each working mode is determined by combining the interference coefficient of all classes under each working mode with the change rate of the change relationship. Based on the optimal heat input, the welding speed at each moment under each working mode during the current sheet metal welding is determined. Combined with the control coefficient and the arc voltage at each moment during the current sheet metal welding, the arc voltage at the next moment under each working mode during the current sheet metal welding is controlled.

2. The multi-mode heat input coordinated control device for argon arc welding machine based on sheet metal processing according to claim 1 is characterized in that: The reference features for evaluating the welding quality of each sheet metal part include the weld formation coefficient, dimensional accuracy, and welding uniformity of the sheet metal part; the value range of the welding quality score is [0, 1].

3. The multi-mode heat input coordinated control device for argon arc welding machine based on sheet metal processing according to claim 1 is characterized in that: The reference position is the position corresponding to the welding quality score of each type of sheet metal part being greater than a preset threshold.

4. The multi-mode heat input coordinated control device for argon arc welding machine based on sheet metal processing according to claim 1, characterized in that: Determining the appropriate heat input range corresponding to each operating mode in each category includes: The working modes during sheet metal welding include direct current mode and pulse mode. The minimum and maximum values ​​of the heat input of the sheet metal corresponding to all reference positions belonging to the direct current mode in each category are obtained, and the numerical range formed by the minimum and maximum values ​​is used as the appropriate heat input range corresponding to the direct current mode in each category. Accordingly, the suitable heat input range corresponding to each type of pulse mode is obtained.

5. The multi-mode heat input coordinated control device for argon arc welding machine based on sheet metal processing according to claim 1, characterized in that: The expression of the objective function is: ; Where f is the objective function, is the difference in heat input between the i-th position and the i+1-th position during the welding of the current sheet metal part. is the difference between the heat input at the i-th position during the welding of the current sheet metal and the middle value of the corresponding heat input suitable range, and D is the number of welding positions of the current sheet metal.

6. The multi-mode heat input coordinated control device for argon arc welding machine based on sheet metal processing according to claim 1, characterized in that: The welding speed characteristic factor is the product of the inverse of the discrete degree of the welding speed of the sheet metal parts corresponding to each position in each category during welding and the average level.

7. The multi-mode heat input coordinated control device for argon arc welding machine based on sheet metal processing according to claim 1, characterized in that: Determining the interference coefficient of each working mode in each category includes: For each working mode in each category, the welding speed characteristic factor at each position is used as the horizontal coordinate, and the welding quality score of the sheet metal parts at each position is used as the vertical coordinate. The fitting curve of the welding quality score of the sheet metal parts at all positions under each working mode in each category with respect to the welding speed characteristic factor is obtained. The difference between the welding quality scores of each welding position on the fitting curve and its adjacent previous position is calculated and recorded as the first difference. The ratio of the sum of all the first differences corresponding to the fitting curve to the sum of the absolute values ​​of all the first differences is calculated as the interference coefficient of the working mode corresponding to the fitting curve in each category.

8. The multi-mode heat input coordinated control device for argon arc welding machine based on sheet metal processing according to claim 7, characterized in that: Determining the control coefficient of each working mode includes: Calculate the mean of the slopes of all welding positions on the fitting curve, calculate the product of the mean and the interference coefficient of the working mode corresponding to the fitting curve in each category, record it as the first product, and take the mean of the first product in all categories under each working mode as the control coefficient of each working mode.

9. The multi-mode heat input coordinated control device for argon arc welding machine based on sheet metal processing according to claim 1, characterized in that: The determining of the welding speed at each moment in each working mode during the current sheet metal welding includes: The calculation formula of welding heat input is used, and the optimal heat input of each welding position under each working mode during the current sheet metal welding is taken as a known quantity. Combined with the arc voltage and current at each welding position at the corresponding moment during welding, the welding speed at each moment under each working mode during the current sheet metal welding is obtained.

10. The multi-mode heat input coordinated control device for argon arc welding machine based on sheet metal processing according to claim 1, characterized in that: The method of regulating the arc voltage at the next moment in each working mode during the current sheet metal welding comprises: Calculate the product of the welding speed at each moment in each working mode during the current sheet metal welding and the control coefficient of each working mode, and record it as the second product. The sum of the arc voltage at each moment in each working mode during the current sheet metal welding and the second product is used as the arc voltage at the next moment in each working mode during the current sheet metal welding.

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