Adaptive parameter adjusting method based on welding process database

Abstract

The invention discloses a parameter self-adaptive adjustment method based on a welding process database. The method comprises the steps that an initial process database containing pipe parameters, welding parameters and angle parameters is constructed; segmenting the circumferential weld according to the piecewise function; for the current segment, the angle parameter of the current segment is calculated, if the parameter exists in the database, the corresponding welding parameter is directly called, and otherwise, the parameter is obtained through interpolation calculation; welding is conducted according to the determined parameters, and meanwhile the new parameter pairs are stored in a database to achieve self-adaptive expansion; according to the method, the operation difficulty and the dependence on the skills of welders can be reduced, the bottleneck of manual welding in speed and endurance is broken through, the operation efficiency is remarkably improved, the final assembly period of ship construction is shortened, and the long-term manpower and quality cost is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of welding technology, and in particular to a parameter self-adaptive adjustment method based on a welding process database. BACKGROUND

[0002] In the heavy industry fields such as shipbuilding, chemical industry and energy, pipeline systems undertake the key task of conveying various media. The welding quality is directly related to the safety, sealing and long-term reliability of the entire system. At present, the technical path to realize pipeline welding automation mainly includes three types: automatic welding special machine, all-position welding equipment and industrial robot welding workstation.

[0003] The automatic welding special machine is suitable for large-batch straight pipe welding, has low cost, high welding precision and consistent weld quality, but is not suitable for complex post-assembly conditions.

[0004] The all-position welding equipment is suitable for complex conditions, but the molten pool shape and gravity influence of different positions are quite different, and the welding parameters need to be adjusted constantly during the welding process to ensure the weld formation. However, the welding parameter adjustment of the all-position welding equipment is not flexible and relies on the experience of on-site engineers.

[0005] The industrial robot welding workstation is commonly used for complex welds such as intersecting lines. For complex post-assembly conditions with simple welds (such as butt ring seams), the industrial robot workstation has no advantage in terms of economy and efficiency.

[0006] Since the above-mentioned equipment is not suitable for ship pipeline welding, complex pipeline welding is usually performed manually. Manual welding has the following problems: 1. Poor quality consistency and reliability: The welding quality is highly dependent on the skill level, working state and experience of the welder. Different welders or even the same welder at different times have different welding effects, making it difficult to achieve standardized and traceable quality control, which poses a safety hazard to the entire pipeline system.

[0007] 2. Low parameter control precision: Manual welding cannot accurately and stably control key parameters such as welding current, voltage, speed and welding torch angle. Especially in all-position welding with poor spatial position, it is difficult to effectively overcome the influence of gravity on the molten pool, which may result in undercut, incomplete penetration and welding bead defects.

[0008] 3. Efficiency and cost issues: Skilled welders require a long training period and increasing labor costs, and the welding environment is harsh, with high labor intensity, which may lead to fatigue work and further affect quality and efficiency. At the same time, manual welding is slow, which becomes one of the bottleneck links of the total assembly period of shipbuilding.

[0009] Therefore, the existing manual welding technology is difficult to simultaneously consider the efficiency and precision of the welding of the complex pipe system, thereby affecting the overall shipbuilding. SUMMARY

[0010] The present application provides a parameter adaptive adjustment method based on a welding process database to overcome the above technical problems.

[0011] To achieve the above-mentioned purpose, the technical scheme of the present application is: A parameter adaptive adjustment method based on a welding process database, comprising: S1: constructing an initial process database based on a welding process procedure, wherein the initial process database comprises one-to-one pipe material parameters, welding parameters and angle parameters; S2: defining a piecewise function, segmenting the annular weld according to the piecewise function, and obtaining the start angle and end angle of each segment; S3: for the current weld segment, calculating the angle parameter according to the start angle and end angle, if the angle parameter is in the initial process database, directly calling the welding parameter corresponding to the angle parameter, if the angle parameter is not in the initial process database, finding the first two angle parameters closest to the angle parameter in the initial process database, and calculating the corresponding welding parameter based on the two angle parameters; S4: generating a welding instruction according to the welding parameter determined in S3, controlling the welding machine to automatically weld the current weld segment according to the welding instruction, and saving the welding parameter and the corresponding angle parameter as a new record to the initial process database, to complete the adaptive expansion of the initial process database and realize the adaptive adjustment of the welding parameter; S5: repeating steps S3 to S4 until all weld segments are welded.

[0012] Further, the piecewise function is defined, the weld is segmented according to the piecewise function, and the start angle and end angle of each segment are obtained, comprising: S21, defining a piecewise function, as shown in formula (1), (1) Wherein, is the number of entries recorded in the initial process database; S22, segmenting the annular weld based on the value of to obtain the start angle and end angle of each segment.

[0013] Further, the angle parameter is calculated according to the start angle and end angle, comprising: The angle parameter is calculated according to the start angle and end angle, as shown in formula (2), (2) wherein, represents the start angle, represents the end angle.

[0014] Further, if the M value is not in the initial process database, the angle parameters in the initial process database are sorted from large to small, the difference between all angle parameters and the M value is calculated, and one of the angle parameters with the smallest difference is selected in the angle parameter larger than the M value and the angle parameter smaller than the M value, and is set as b1 and b2.

[0015] Further, the corresponding welding parameters are calculated based on the two angle parameters, including: The weights are calculated based on b1 and b2, as shown in formulas (3) and (4), (3) (4) wherein, is the first weight, is the second weight; The welding parameters corresponding to the M value are calculated according to the first weight and the second weight, as shown in formula (5), (5) wherein, represents each data in the welding parameters corresponding to b1, represents each data in the welding parameters corresponding to b2.

[0016] Further, the welding instruction is generated according to the welding parameters determined in S3, the welding machine is controlled to automatically weld the current weld segment according to the welding instruction, if the welded weld segment passes the non-destructive testing, the angle parameter and the welding parameter corresponding to the weld segment are saved to the initial process database, if the welded weld segment does not pass the non-destructive testing, the welding current, the welding voltage and the welding speed in the welding parameters corresponding to the angle parameter are analyzed according to the heat input empirical formula, as shown in formula (6), (6) The welding current, the welding voltage and the welding speed after each adjustment are used for actual weld welding test until the weld passes the non-destructive testing, and the welding current, the welding voltage and the welding speed passing the non-destructive testing are saved to the initial process database for subsequent welding of the weld segment.

[0017] Beneficial effects: the present application provides a parameter self-adaptive adjustment method based on a welding process database, which has the following beneficial effects: 1. The welding quality is standardized and highly consistent, and the reliability is significantly improved: by building an initial process database and expanding the process database, the selection and development of welding process parameters are changed from relying on individual experience to relying on objective and standard database systems; The entire welding process is automated, ensuring that the process parameters are highly consistent when the same specification product is welded by different equipment at different times, and achieving standardization of welding quality and traceability of results; 2. Precise and intelligent control of key parameters for all-position welding is achieved: by defining a segmented function of the circular weld and calculating welding parameters based on angle parameters, the optimal welding parameters can be quickly matched or calculated for each spatial position of the weld, solving the problem of low parameter control accuracy in manual welding in harsh spatial positions; 3. It has self-learning and continuous optimization capability, and the welding precision is continuously improved with use: save the new parameter pairs (angle parameter-welding parameter) that are calculated and successfully applied during welding, realize dynamic expansion of the process database, and continuously accumulate "compliant data". With the growth of database data, the segmented data points are more dense and closer to reality, and the generated welding parameters are more accurate, and the welding precision is higher.

[0018] In summary, the present application greatly reduces the operation difficulty and the dependence on the skill of the welder, breaks the bottleneck of manual welding in speed and endurance, significantly improves the work efficiency, shortens the total assembly cycle of shipbuilding, and reduces the long-term labor and quality cost. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor.

[0020] Figure 1 A method flowchart of a parameter self-adaptive adjustment method based on a welding process database provided by the present application; Figure 2 A schematic diagram of a collaborative robot; Figure 3 An example diagram of a piece of data in the initial process database. DETAILED DESCRIPTION

[0021] In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0022] The embodiment provides a parameter adaptive adjustment method based on a welding process database, as shown in Figure 1 The embodiment provides a parameter adaptive adjustment method based on a welding process database, as shown in S1: constructing an initial process database based on a welding process procedure, the initial process database comprising one-to-one pipe material parameters, welding parameters and angle parameters; S2: defining a piecewise function, segmenting the annular weld according to the piecewise function to obtain a start angle and an end angle of each segment; S3: for the current weld segment, calculating the angle parameter according to the start angle and the end angle, if the angle parameter is in the initial process database, directly calling the welding parameter corresponding to the angle parameter, if the angle parameter is not in the initial process database, finding the two closest angle parameters in the initial process database, and calculating the corresponding welding parameter based on the two angle parameters; S4: generating a welding instruction according to the welding parameter determined in S3, controlling the welding machine to automatically weld the current weld segment according to the welding instruction, and saving the welding parameter and the corresponding angle parameter as a new record to the initial process database, to complete adaptive expansion of the initial process database and realize adaptive adjustment of the welding parameter; S5: repeating steps S3 to S4 until all weld segments are welded.

[0023] Specifically, the present application is carried on the upper computer, cooperates with the collaborative robot and the laser sensor, and cooperates with each other to, welds the collaborative robot as Figure 2 The embodiment provides a parameter adaptive adjustment method based on a welding process database, as shown in Secondly, the geometric features and spatial positions of the welds to be welded are determined by a laser sensor, the ring-shaped weld is identified by the upper computer, a piecewise function is defined, the ring-shaped weld is segmented according to the piecewise function, the start angle and the end angle of each segment are obtained, for each segment of the weld, the angle parameter is calculated according to the start angle and the end angle, if the angle parameter is in the initial process database, the welding parameter corresponding to the angle parameter is directly called, if the angle parameter is not in the initial process database, the two closest angle parameters to the angle parameter are found in the initial process database, the corresponding welding parameters are calculated based on the two angle parameters, the selection and development of the welding process parameters are changed from relying on the personal experience of the welder to relying on the objective and standard database system, and the welding precision is improved. Finally, the welding parameters determined in S3 are used to generate welding instructions, the welding program is generated according to the welding instructions, the upper computer is used to control the collaborative robot to automatically weld each segment of the weld according to the welding program, and the welding process is saved as a new record in the initial process database, so that the initial process database is adaptively expanded, the adaptive adjustment of the welding parameters is realized, and the welding process is completed.

[0024] In specific embodiments, the initial process database is constructed based on a welding process specification, and the scheme of one-to-one correspondence of the pipe material parameters, the welding parameters and the angle parameters is as follows: The initial process database is built based on the welding process specification, and the welding process specification gives the parameters required in the welding process, such as Figure 3 As shown in the table, the table includes process number, base material type, single / multi-pass, welding material diameter, welding current, welding voltage, welding speed. The data acquisition and data storage of the initial process database are as follows: 1) Data acquisition: through the man-machine interface, the management personnel enter the welding process related parameters according to the welding process specification: pipe material parameters (material, pipe diameter, wall thickness), welding parameters (welding position and direction, welding current, voltage, welding speed, gas flow) and other information; Considering the influence of gravity on the welding quality, the angle parameter is added to the welding parameters; the value of the angle parameter is the included angle between the welding torch and the horizontal plane, and the angle parameters in the initial process database are obtained according to the actual experience and welding test; 2) Data storage: a structured database is established, and the collected data is stored in categories; data record entries are created according to the process number in the welding process specification, which can be indexed by welding method, base material type and welding material diameter, so as to facilitate quick data retrieval and calling.

[0025] In specific embodiments, the piecewise function is defined, the ring-shaped weld is segmented according to the piecewise function, and the scheme of obtaining the start angle and the end angle of each segment is as follows: S21, define a segment function, as shown in formula (7), (7) wherein, is the number of entries recorded in the initial process database; S22, segment the circular weld based on the value of , for example, when the value of s is 4, is 90 degrees, and the circular weld is divided into 4 segments using 90 degrees, the starting angle of the first segment is 0 degrees, and the ending angle is 90 degrees, and so on, the starting angle of the last segment is 270 degrees, and the ending angle is 360 degrees.

[0026] Specifically, as shown in Figure 2 , the laser sensor is arranged on the collaborative robot, the geometric features and spatial position of the weld are identified by using the dragging function of the collaborative robot and the laser sensor, the weld recognition is performed by the upper computer, the weld data is determined, and then the weld is segmented by the segment function.

[0027] In this scheme, the continuous weld can be discretized, the complexity of parameter calculation is reduced, and each segment of welding parameters is matched with the local working condition to adapt to complex weld requirements.

[0028] In specific embodiments, for the current weld segment, the angle parameter is calculated according to the starting angle and the ending angle, if the angle parameter is in the initial process database, the welding parameter corresponding to the angle parameter is directly called, if the angle parameter is not in the initial process database, the two closest angle parameters in the initial process database are found, and the scheme for calculating the corresponding welding parameters based on the two angle parameters is: S31, calculate the angle parameter according to the starting angle and the ending angle, as shown in formula (8), (8) wherein, represents the starting angle, represents the ending angle; If the angle parameter is in the initial process database, the welding parameter corresponding to the angle parameter is directly called, if the value of M is not in the initial process database, the angle parameters in the initial process database are sorted from large to small, the difference between all angle parameters and the value of M is calculated, and one of the angle parameters with the smallest difference is selected in the angle parameter greater than the value of M and the angle parameter smaller than the value of M, and is set as b1 and b2. Calculate the weight based on b1 and b2, as shown in formulas (9) and (10), (9) (10) wherein, is a first weight, is a second weight; the welding parameters corresponding to the M value are calculated according to the first weight and the second weight, as shown in formula (11), (11) wherein, represents each data in the welding parameters corresponding to b1, represents each data in the welding parameters corresponding to b2, wherein the welding parameters include welding current, welding voltage and welding speed.

[0029] In this scheme, if there are corresponding welding parameters in the database, the existing parameters can be directly called to save time, especially for repetitive welds, while calculating the angle parameters of each position, solving the working conditions not covered by the database, and improving the generalization ability.

[0030] In a specific embodiment, a welding instruction is generated according to the welding parameters determined in S3, the collaborative robot is controlled to automatically weld the current weld segment according to the welding instruction, and the welding parameters and the corresponding angle parameters are saved as new records to the initial process database, so as to complete the adaptive expansion of the initial process database and realize the scheme of adaptive adjustment of the welding parameters: The host computer generates a welding instruction string according to the determined welding parameters, the welding instruction includes an arc striking instruction, a swing start instruction, a motion instruction, a swing end instruction and an arc collecting instruction, the welding instructions are combined into a multi-instruction sequence, and a welding program is obtained; The generated welding program is sent to the robot controller to control the collaborative robot to weld according to the welding program; After each segment welding is completed, non-destructive testing is performed, in this embodiment, the non-destructive testing uses ultrasonic flaw detection method, which is a conventional technical means in the art, and this embodiment does not describe and limit it; If the welded weld passes the non-destructive testing, the angle parameters and the welding parameters corresponding to the weld are saved to the initial process database, if the welded weld does not pass the non-destructive testing, the weld that does not pass the non-destructive testing is re-welded manually, and the welding current, welding voltage and welding speed in the welding parameters corresponding to the angle parameters are analyzed according to the heat input empirical formula, as shown in formula (12), (12) The heat input parameter range is determined with reference to the Welding Procedure Specification; in this embodiment, the Mechanical Manual is consulted to obtain the tungsten argon arc welding heat efficiency of 0.65-0.85, and the value is 0.8; In the case of ensuring heat input, the welding current, the welding voltage and the welding speed are artificially adjusted, and the welding test of the actual weld is carried out using the welding current, the welding voltage and the welding speed after each adjustment until the weld passes the nondestructive testing, the welding current, the welding voltage and the welding speed passing the nondestructive testing are saved in the initial process database for the welding of subsequent welds.

[0031] In the scheme, the new parameters are saved in real time, the database is dynamically updated, the artificial intervention is gradually reduced, the instructions are automatically generated to avoid the artificial operation error, and the weld quality stability can be improved.

[0032] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for adaptive adjustment of parameters based on a welding process database, characterized in that, Comprise: S1: Construct an initial process database based on a welding process specification, the initial process database comprising one-to-one pipe material parameters, welding parameters and angle parameters; S2: Define a segmentation function, segment the girth weld according to the segmentation function, and obtain the start angle and end angle of each segment; S3: For the current weld segment, calculate the angle parameter according to the start angle and end angle, if the angle parameter is in the initial process database, directly call the welding parameter corresponding to the angle parameter, if the angle parameter is not in the initial process database, find the two closest angle parameters in the initial process database, and calculate the corresponding welding parameter based on the two angle parameters; S4: Generate a welding instruction according to the welding parameter determined in S3, control the collaborative robot to automatically weld the current weld segment according to the welding instruction, and save the welding parameter and the corresponding angle parameter as a new record to the initial process database to complete the adaptive expansion of the initial process database and realize the adaptive adjustment of the welding parameter; S5: Repeat steps S3 to S4 until all weld segments are welded.

2. The method for parameter self-adaptive adjustment based on a welding process database according to claim 1, characterized in that, Define a segmentation function, segment the weld according to the segmentation function, and obtain the start angle and end angle of each segment, comprising: S21, define a segmentation function, as shown in formula (1), （1） wherein, is the number of entries recorded in the initial process database; S22、based on The value of the annular weld is segmented to obtain the starting angle and the ending angle of each segment.

3. The method for parameter self-adaptive adjustment based on welding process database according to claim 1, characterized in that, Calculate the angle parameter according to the start angle and end angle, comprising: Calculate the angle parameter according to the start angle and end angle, as shown in formula (2), （2） wherein denotes the start angle, denotes the end angle.

4. The method for parameter self-adaptive adjustment based on welding process database according to claim 3, characterized in that, If the M value is not in the initial process database, sort the angle parameters in the initial process database from large to small, calculate the difference between all angle parameters and M value, and select an angle parameter with the smallest difference in the angle parameter larger than M value and the angle parameter smaller than M value, respectively, and set as b1 and b2.

5. The method for parameter self-adaptive adjustment based on welding process database according to claim 4, characterized in that, Calculate the corresponding welding parameter based on the two angle parameters, comprising: Calculate the weight based on b1 and b2, as shown in formulas (3) and (4), （3） （4） wherein is a first weight, is a second weight; Calculate the welding parameter corresponding to M value according to the first weight and the second weight, as shown in formula (5), （5） wherein, represents each data in the welding parameters corresponding to b1, represents each data in the welding parameters corresponding to b2.

6. The method for parameter self-adaptive adjustment based on a welding process database according to claim 1, characterized in that, Generate a welding instruction according to the welding parameter determined in S3, control the collaborative robot to automatically weld the current weld segment according to the welding instruction, if the welded weld segment passes the nondestructive testing, save the angle parameter and the welding parameter corresponding to the weld segment to the initial process database, if the welded weld segment does not pass the nondestructive testing, analyze the welding current, welding voltage and welding speed in the welding parameter corresponding to the angle parameter according to the heat input empirical formula, as shown in formula (6), （6） Use the adjusted welding current, welding voltage and welding speed each time to test the actual weld, until the weld passes the nondestructive testing, save the welding current, welding voltage and welding speed that pass the nondestructive testing and the corresponding angle parameter to the initial process database for subsequent weld segment welding.

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