Welding control method, system, program product, medium and apparatus

Abstract

The invention provides a welding control method, system, program product, medium and equipment, the welding control method is used for laser welding of a car roof and a car body side wall, and the welding control method comprises the following steps that the welding seam depth of at least one point in welding seams between the car roof and the car body side wall to be welded is collected; calculating a matching gap of the car roof and the side wall of the car body at the corresponding position of the at least one point according to the depth of the welding seam; the welding speed is determined according to the matching gap, and a welding execution mechanism is controlled to conduct welding at the at least one point at the corresponding welding speed; the welding control method can improve the welding quality of car roof laser welding and reduce the repair rate and the welding cost.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of vehicle welding, in particular to a welding control method, system, program product, medium and device. BACKGROUND

[0002] With the continuous development of the automobile industry and the deepening of the industrial 4.0 strategy, higher requirements are put forward for the stability and intelligentization of the body manufacturing process. As a key process in vehicle body manufacturing, roof laser welding has been widely used in major vehicle manufacturing enterprises. However, the quality of this process is still affected by many factors, especially the fluctuation of the matching gap of the weld, which involves the dimensional accuracy of multiple sub-assemblies such as side walls, lower vehicle bodies, roof covers, the stability of tooling fixtures, and the consistency of the welding process. The system has high complexity and long size chain, resulting in great difficulty in gap control.

[0003] At present, due to unstable matching gap, defects such as welding deviation, welding penetration, and broken welding occur frequently, and the industry average repair rate is about 10%. To deal with this problem, the production line usually sets up a special manual repair station to repair the roof parts after welding by the welding robot.

[0004] It should be noted that the information disclosed in the above background section is only used to strengthen the understanding of the background of the present disclosure, and therefore can include information that does not constitute prior art known to those skilled in the art. SUMMARY

[0005] One aspect of the present application aims to solve the technical problem of how to improve the welding quality of roof laser welding.

[0006] In addition, other aspects of the present application also aim to solve or alleviate other technical problems existing in the prior art.

[0007] The present application provides a welding control method, system, program product, medium and device. Specifically, according to one aspect of the present application, there is provided: A welding control method for laser welding of a roof and a body side wall, comprising the following steps: Collecting the weld depth at at least one point in the weld between the roof to be welded and the body side wall; Calculating the matching gap of the roof and the body side wall at the corresponding position of the at least one point according to the weld depth; Determining the welding speed according to the matching gap, and controlling the welding execution mechanism to weld at the at least one point at the corresponding welding speed.

[0008] Optionally, according to one embodiment of the present application, calculating the matching gap of the roof and the body side wall at the corresponding position of the at least one point according to the weld depth comprises the following steps: acquiring the weld seam depth at the corresponding point of the welded sample with standard weld seam and the matching gap at the corresponding position as the standard weld seam depth and the standard matching gap; calculating the depth difference of the weld seam depth of at least one point between the roof and the body side frame to be welded and the standard weld seam depth; calculating the corresponding matching gap difference according to the depth difference; calculating the matching gap of the roof and the body side frame at the corresponding position of the at least one point according to the standard matching gap and the matching gap difference.

[0009] Optionally, according to an embodiment of the present application, the geometric conversion relationship between the matching gap difference and the depth difference is determined based on the roof turn-up angle according to the following formula: ΔG = Δh * sinα; wherein ΔG is the matching gap difference, Δh is the depth difference, and α is the roof turn-up angle, which is the angle between the roof turn-up and the z-axis of the vehicle coordinate system.

[0010] Optionally, according to an embodiment of the present application, the acquisition of the weld seam depth at at least one point of the weld seam between the roof and the body side frame to be welded includes the following steps: controlling the welding execution mechanism to move so that the end of the welding wire contacts the bottom of the weld seam at the point; calculating the weld seam depth of the weld seam at the point in real time according to the coordinates of the point in the vehicle coordinate system.

[0011] Optionally, according to an embodiment of the present application, the welding speed is obtained from a relational database according to the matching gap, wherein the relational database includes the optimal relationship between the welding speed and the matching gap based on the fixed welding power and the wire feed speed by orthogonal experiment method.

[0012] Optionally, according to an embodiment of the present application, the welding speed of the welding execution mechanism is dynamically adjusted according to the real-time point position of the weld seam.

[0013] Optionally, according to an embodiment of the present application, the method includes the following steps: judging whether the depth difference exceeds a preset difference threshold value; in response to the depth difference exceeding the preset difference threshold value, using the welding speed corresponding to the standard matching gap to weld at the corresponding point and recording the position; after the welding is completed, the position point is re-welded.

[0014] According to a second aspect of the present application, the present application provides a welding control system for laser welding of a roof and a body side frame, which includes: a collection module configured to collect a weld joint depth at at least one point in a weld joint between a roof and a side wall of a vehicle body to be welded; a calculation module configured to calculate a matching gap of the roof and the side wall at a corresponding position of the at least one point according to the weld joint depth; a control module configured to determine a welding speed according to the matching gap and control a welding execution mechanism to weld at the at least one point at the corresponding welding speed; a welding execution mechanism configured to receive a control signal from the control module and weld at the corresponding welding speed according to the control signal.

[0015] Optionally, according to an embodiment of another aspect of the present application, the welding execution mechanism is configured as a welding robot or a mechanical arm, and the collection module is integrally integrated with the welding execution mechanism and includes a welding wire arranged on the welding robot or the mechanical arm.

[0016] Optionally, according to an embodiment of another aspect of the present application, a relationship database of the matching gap and the welding speed is stored in the control module, which includes an optimal relationship of the welding speed and the matching gap based on a fixed welding power and a wire feeding speed by an orthogonal experiment method.

[0017] Optionally, according to an embodiment of another aspect of the present application, the welding control system further includes a learning optimization module configured to collect weld joint quality data in an actual welding process and used to optimize and update the relationship database.

[0018] According to a third aspect of the present application, the present application provides a computer program product including a computer program, which, when executed, implements the above-mentioned welding control method.

[0019] According to a fourth aspect of the present application, the present application provides a computer readable storage medium, which stores a computer program, which, when executed by a processor, implements the above-mentioned welding control method.

[0020] According to a fifth aspect of the present application, the present application provides a computer device including a memory, a processor, and a computer program stored on the memory and executable on the processor, wherein the processor, when executing the computer program, implements the above-mentioned welding control method.

[0021] The advantages of the present application include: 1. The welding control method according to one embodiment of the present application calculates the matching gap between the roof and the side wall of the vehicle body by the weld depth, and selects the appropriate welding speed for the roof according to the matching gap, so as to greatly improve the welding quality of the roof laser welding, and reduce the repair rate and welding cost; 2. The welding control method according to one embodiment of the present application processes the weld depth and the matching gap data of the welding piece based on the standard weld depth and the standard matching gap of the sample piece, and calculates the welding speed based on the optimal relationship between the welding speed and the matching gap under the fixed laser power and the wire feeding speed obtained by the orthogonal test, so as to more accurately and adaptively match the welding speed at each part of the weld. 3. The welding control method according to one embodiment of the present application can directly use the welding wire to measure the weld depth, without the need of additional depth measuring tools, and can also continuously learn and optimize the corresponding relationship between the matching gap and the welding speed during the welding process, so as to further improve the welding precision and the welding quality. BRIEF DESCRIPTION OF DRAWINGS

[0022] The above and other features of the present application will become apparent from the following description of the embodiments thereof, taken in conjunction with the accompanying drawings, which are given by way of illustration and are not intended to be limiting of the present application. In the drawings: Figure 1 Fig. 1 shows a flow diagram of the welding control method according to one embodiment of the present application; Figure 2 Fig. 2 shows a schematic diagram of the geometric relationship between the depth difference and the matching gap difference; Figure 3 Fig. 3 shows a schematic diagram of the module of the welding control system according to one embodiment of the present application. DETAILED DESCRIPTION

[0023] It is to be understood that the technical solution according to the present application can be implemented in many different ways, and any changes or modifications made by those skilled in the art without departing from the spirit of the present application shall fall within the scope of the present application. Therefore, the following detailed description and the accompanying drawings are merely illustrative of the technical solution of the present application, and should not be regarded as the whole or as limiting the technical solution of the present application.

[0024] The orientation terms mentioned or possibly mentioned in the present specification, such as up, down, left, right, front, back, front side, back side, top, bottom, etc., are defined with respect to the structure shown in the drawings, and are relative concepts, so they can change accordingly according to different positions and different use states. Therefore, these or other orientation terms should not be interpreted as restrictive terms. In addition, the terms "first", "second", "third" or similar expressions are only used for description and differentiation purposes, and cannot be understood as indicating or implying the relative importance of the corresponding components or the sequence or assembly sequence of the components.

[0025] Reference Figure 1 which shows a flowchart of a welding control method according to an embodiment of the present application. The welding control method of the present application can calculate the matching gap of the roof and the side wall of the vehicle body according to the weld depth, and match the appropriate welding speed according to the calculated matching gap, so as to improve the welding quality of the roof laser welding, which includes the following steps: Collecting the weld depth at at least one point in the weld between the roof to be welded and the side wall of the vehicle body; Calculating the matching gap of the roof and the side wall of the vehicle body at the corresponding position of the at least one point according to the weld depth; Determining the welding speed according to the matching gap, and controlling the welding execution mechanism to weld at the at least one point at the corresponding welding speed.

[0026] It should be understood that the collection of weld depth is not limited to a specific point. In this welding control method, the weld depth of a specific point in the weld can be collected, such as measuring at a key position point set in the weld or at multiple points uniformly distributed in the weld, or the depth of the weld can be collected along the weld in real time and continuously. In the latter case, the welding speed of the welding execution mechanism is continuously and dynamically adjusted according to the real-time point of the weld, which can better adjust the welding speed in real time to improve the welding quality, and these cases should be included in the protection scope of the present application.

[0027] In an embodiment of the present application, calculating the matching gap of the roof and the side wall of the vehicle body at the corresponding position of the at least one point according to the weld depth includes the following steps: Obtaining the weld depth at the corresponding point and the matching gap at the corresponding position of the welded sample with standard weld as standard weld depth and standard matching gap; Calculating the depth difference between the weld depth of at least one point in the weld between the roof to be welded and the side wall of the vehicle body and the standard weld depth; Calculating the corresponding matching gap difference according to the depth difference; The matching gap of the roof and the body side frame at the corresponding position of the at least one point is calculated according to the standard matching gap and the matching gap difference value.

[0028] In this embodiment, when the matching gap is calculated by the weld depth, first, a sample is taken as a reference. The sample can be another welded roof of the same type or another welded vehicle with the same type of roof, and the sample has a relatively perfect weld in the weld quality evaluation system, which at least does not have any welding deviation, welding through, welding breakage and other problems, and does not need to be repaired, and the weld as a whole has a relatively small matching gap, which is referred to as a standard weld in this application. The weld depth and the matching gap of the standard weld are used as the standard weld depth and the standard matching gap to measure the weld depth and the matching gap of the weld between the roof to be welded and the body side frame.

[0029] In this embodiment, after the weld depth at the above-mentioned point is measured, first, the difference between the weld depth and the standard weld depth is obtained to obtain the matching gap difference value by the depth difference value. Referring to Figure 2 which shows the geometric relationship between the depth difference value and the matching gap difference value. Figure 2 The part shown by the dashed line in the middle is the roof part 10 of the sample, and the part shown by the solid line is the roof 101 to be welded and the body side frame 102. From Figure 2 It can be seen from the geometric relationship between the depth difference value and the matching gap difference value at the corresponding point, which is schematically shown in the form of a triangle in the lower right corner of the picture. Among them, α is the roof turn-up angle, that is, the angle between the roof turn-up and the z-axis of the vehicle coordinate system, h1 is the weld height of a point in the roof part 10 of the sample, h2 is the weld height of the corresponding point of the roof 101 to be welded, G1 is the matching gap of the roof part 10 of the sample at the current position, and G2 is the matching gap of the roof 101 to be welded at the corresponding position. Δh is the difference between h2 and h1, and ΔG is the difference between G2 and G1. From the geometric relationship in the figure, it can be deduced that the geometric conversion relationship between the matching gap difference value and the depth difference value based on the roof turn-up angle is: ΔG = Δh * sinα; Where ΔG is the matching gap difference value, Δh is the depth difference value, and α is the roof turn-up angle, which is the angle between the roof turn-up and the z-axis of the vehicle coordinate system.

[0030] That is, the depth difference between the current to-be-welded roof weld and the corresponding point of the sample weld (the point at the same position on the roof) can be used to calculate the matching gap difference between the to-be-welded roof weld and the sample weld at the corresponding position of the point based on the roof turn-up angle, and finally the matching gap of the to-be-welded roof weld at the corresponding position of the point can be obtained by adding the standard matching gap and the matching gap difference. Therefore, the weld depth and the matching gap of the sample can be said to be intermediate quantities as standards, the roof turn-up angle of the sample is the same as that of the to-be-welded roof, on the one hand, the relationship between the depth difference and the matching gap difference can be determined through this geometric relationship, so that the matching gap of the to-be-welded roof weld can be obtained according to the weld depth and the known matching gap of the sample weld; on the other hand, the sample weld is the standard weld described above, which has a higher weld quality, and the welding speed matched with the sample weld is also a relatively good welding speed, so the welding speed of the to-be-welded roof can also be adjusted from the relatively good welding speed, which can further improve the welding quality and reduce the welding speed fluctuation.

[0031] In an embodiment of the present application, the weld depth at at least one point in the weld between the to-be-welded roof and the body side wall is collected by the following steps: controlling the welding execution mechanism to move so that the end of the welding wire contacts the bottom of the weld at the point; calculating the weld depth at the point in real time according to the coordinates of the point in the vehicle coordinate system.

[0032] In this embodiment, no additional weld depth measuring mechanism is needed, but the welding wire of the laser welding is used to collect the weld depth. The welding wire needs to contact the bottom of the weld during welding, and the position of the welding wire is collected in real time by the control unit in the form of coordinates in the vehicle coordinate system to monitor and adjust the current welding trajectory. In this case, the weld depth of the part contacted by the welding wire can be accurately calculated through the coordinates, which not only saves computing power, but also can obtain accurate weld depth data.

[0033] In an embodiment of the present application, the welding speed is obtained from a relational database according to the matching gap, and the relational database includes the optimal relationship between the welding speed and the matching gap based on the fixed laser power and the wire feed speed by the orthogonal experiment method.

[0034] The most critical and most directly affected parameters of laser welding include welding speed, wire feeding speed, welding power, lateral force, focal length, etc. The welding speed directly affects the wire filling amount and the heat input size of the laser welding wire, and also directly affects the quality of the weld, and its size can be adjusted by controlling the speed of the robot and has a fast response speed. The welding speed is adjusted by setting the parameters of the wire feeder. For the same weld, the wire feeding speed is generally constant, but if the weld gap is uniform and stable, the welding quality can be optimized by adjusting the wire feeding speed. However, this adjustment can only be set in advance, and if the adjustment is made during the welding process through PLC, the response speed will be delayed, so it is basically impossible to adjust the wire feeding speed during the welding process to optimize the welding quality. The welding power directly affects the heat input size of the weld, and excessive power can easily cause welding through, and insufficient power can easily cause incomplete fusion. For the same weld, the welding power generally does not change during the laser welding process if the wire diameter is determined. Even if the welding power is adjusted to optimize the welding quality, the entire control process will also have a delay, and it is impossible to adjust the power adaptively. Once the lateral force and focal length are adjusted, they remain basically unchanged during the process, otherwise they will have a greater impact on the quality of the weld. In summary, the adaptive adjustment of the welding speed to match different gaps is the most feasible welding adaptive adjustment method. Therefore, in this embodiment, the optimal welding power, wire feeding speed and welding speed are first obtained by orthogonal test method, then the welding power and wire feeding speed are kept constant due to their characteristics during the welding process, and the corresponding relationship between the matching gap and the welding speed is established according to the experimental data, and the optimal relationship between the matching gap and the welding speed is obtained by evaluating the welding quality. Through this optimal relationship, the optimal welding speed can be obtained through the calculated matching gap, thereby achieving better welding quality.

[0035] In an embodiment of the present application, the welding control method further comprises the following steps: determining whether the depth difference exceeds a preset difference threshold; in response to the depth difference exceeding the preset difference threshold, using the welding speed corresponding to the standard matching gap to weld at the corresponding point and recording the position thereof; after the welding is completed, the position is re-welded.

[0036] If the matching gap at a certain position is too large, for example, exceeds the preset difference threshold, then matching the corresponding optimal welding speed according to the matching gap may cause too large welding speed change and produce jitter or unstable working condition. At this time, the welding speed corresponding to the standard matching gap can be directly used for welding, and the position of the point is recorded, and after the overall welding of the roof is completed, the point is supplemented, so as to improve the welding quality at the point.

[0037] In summary, the welding control method of the present application calculates the matching gap between the roof and the side wall of the vehicle body through the weld depth, and selects the appropriate welding speed for welding the roof through the matching gap, which can realize the adaptive adjustment of the matching gap for the roof laser welding, greatly improve the welding quality of the roof laser welding, reduce the difficulty of perfect welding, and reduce the repair rate and welding cost.

[0038] Reference Figure 3 which shows a module schematic diagram of a welding control system 100 according to one embodiment of the present application. The second aspect of the present application proposes a welding control system 100 for laser welding of the roof and the side wall of the vehicle body, which comprises: The acquisition module 1 acquires the weld depth at at least one point in the weld between the roof to be welded and the side wall of the vehicle body; The calculation module 2 calculates the matching gap of the roof and the side wall of the vehicle body at the corresponding position of the at least one point according to the weld depth; The control module 3 determines the welding speed according to the matching gap, and controls the welding execution mechanism 4 to weld at the at least one point at the corresponding welding speed; The welding execution mechanism 4 receives the control signal from the control module 3, and welds at the corresponding welding speed according to the control signal.

[0039] In one embodiment of the present application, the welding execution mechanism 4 is set as a welding robot or a mechanical arm, the acquisition module 1 is integrally integrated with the welding execution mechanism 4 and includes a welding wire arranged on the welding robot or the mechanical arm.

[0040] In one embodiment of the present application, the relationship database of the matching gap and the welding speed is stored in the control module 3, which includes the optimal relationship between the welding speed and the matching gap based on the fixed welding power and the wire feeding speed through the orthogonal experiment method.

[0041] In one embodiment of the present application, the welding control system 100 further comprises a learning optimization module configured to collect the weld quality data during actual welding process and to optimize and update the relational database. In this embodiment, the learning optimization module is particularly capable of evaluating the weld quality corresponding to different matching gaps and corresponding welding speeds and optimizing the correspondence between the matching gaps and the welding speeds according to the weld quality, for example, corresponding to the improvement of the weld quality at a certain point, the welding speed matching to the matching gap at this point can be updated accordingly, so as to optimize the correspondence between the matching gaps and the welding speeds as a whole.

[0042] The third aspect of the present application provides a computer program product comprising a computer program which, when executed, implements the welding control method described above.

[0043] It can be understood that the computer program product has all the technical effects of the welding control method described above, which will not be repeated here.

[0044] The fourth aspect of the present application provides a computer readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the welding control method described above.

[0045] It can be understood that the computer readable storage medium has all the technical effects of the welding control method described above, which will not be repeated here.

[0046] The fourth aspect of the present application provides a computer device comprising a memory and a processor, the memory being adapted to store a plurality of program codes, the program codes being adapted to be loaded and run by the processor to execute the welding control method described above.

[0047] It can be understood that the computer device has all the technical effects of the welding control method described above, which will not be repeated here. The computer device can include a control device formed by various electronic devices.

[0048] Those skilled in the art can understand that the computer program can be stored in a computer readable storage medium, and the computer program can realize the steps of the above-mentioned method embodiments when the computer program is executed by a processor. The computer program includes computer program code, and the program code includes but is not limited to the program code of the above-mentioned welding control method. For the convenience of description, only the parts related to the present application are shown. The computer program code can be in the form of source code, object code, executable file or some intermediate form. The computer readable storage medium can include any entity or device, medium, U disk, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory, random access memory, electrical carrier signal, telecommunication signal and software distribution medium, etc. that can carry the computer program code. It should be noted that the contents included in the computer readable storage medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction, for example, in some jurisdictions, according to legislation and patent practice, the computer readable storage medium does not include electrical carrier signals and telecommunication signals.

[0049] It should be understood that all the above preferred embodiments are exemplary but not limiting, and various modifications or variations of the above described specific embodiments made by those skilled in the art under the concept of the present application should be within the legal protection scope of the present application.

[0050] The related user personal information that may be involved in the embodiments of the present application is strictly in accordance with the requirements of laws and regulations, follows the principles of legality, legitimacy and necessity, is based on the reasonable purpose of business scene, and processes the personal information provided by the user in the process of using the product / service or generated due to the use of the product / service, and the personal information authorized by the user.

[0051] The user personal information processed by the applicant will be different due to specific product / service scenes, and the specific scenes of the user using the product / service should be used as the standard, which may involve the user's account information, device information, driving information, vehicle information or other related information. The applicant will treat the user's personal information and its processing with high diligence and obligation.

[0052] The applicant attaches great importance to the security of user personal information, and has taken security protection measures in accordance with industry standards, which are reasonable and feasible to protect the user's information and prevent unauthorized access, public disclosure, use, modification, damage or loss of personal information.

Claims

1. A welding control method characterized by, A laser welding method for a roof and a body side wall, comprising the steps of: acquiring a weld seam depth at at least one point of a weld seam between a roof and a body side wall to be welded; calculating a matching gap of the roof and the body side wall at a corresponding position of the at least one point according to the weld seam depth; determining a welding speed according to the matching gap, and controlling a welding execution mechanism to weld at the at least one point at the corresponding welding speed.

2. The welding control method of claim 1, wherein, The step of calculating a matching gap of the roof and the body side wall at a corresponding position of the at least one point according to the weld seam depth comprises the steps of: acquiring a weld seam depth at a corresponding point of a standard weld seam of a standard sample and a matching gap at a corresponding position of the standard weld seam as a standard weld seam depth and a standard matching gap; calculating a depth difference of the weld seam depth of the at least one point of the weld seam between the roof and the body side wall to be welded and the standard weld seam depth; calculating a corresponding matching gap difference according to the depth difference; calculating the matching gap of the roof and the body side wall at the corresponding position of the at least one point according to the standard matching gap and the matching gap difference.

3. The welding control method of claim 2, wherein, A geometric conversion relationship between the matching gap difference and the depth difference is determined according to a roof flanging angle by the following formula: ΔG = Δh * sinα; wherein ΔG is the matching gap difference, Δh is the depth difference, and α is the roof flanging angle, which is an angle between the roof flanging and a z-axis of a vehicle coordinate system.

4. The welding control method of claim 1, wherein, The step of acquiring a weld seam depth at at least one point of a weld seam between a roof and a body side wall to be welded comprises the steps of: controlling the welding execution mechanism to move so that a welding wire end contacts a weld seam bottom at the point; calculating the weld seam depth at the point in real time according to coordinates of the point in a vehicle coordinate system.

5. The welding control method of claim 1, wherein, The welding speed is obtained from a relational database according to the matching gap, wherein the relational database comprises an optimal relationship between the welding speed and the matching gap based on a fixed welding power and a wire feed speed by an orthogonal experiment method.

6. The welding control method of claim 1, wherein, The welding speed of the welding execution mechanism is dynamically adjusted according to a real-time point of the weld seam.

7. A welding control system characterized by, A laser welding method for a roof and a body side wall, comprising: an acquisition module that acquires a weld seam depth at at least one point of a weld seam between a roof and a body side wall to be welded; a calculation module that calculates a matching gap of the roof and the body side wall at a corresponding position of the at least one point according to the weld seam depth; a control module that determines a welding speed according to the matching gap, and controls a welding execution mechanism to weld at the at least one point at the corresponding welding speed; a welding execution mechanism that receives a control signal from the control module, and welds at the corresponding welding speed according to the control signal.

8. A computer program product comprising a computer program, characterized in that, The computer program, when executed, implements the welding control method according to any one of claims 1 to 6.

9. A computer-readable storage medium having stored thereon a computer program, characterized in that The computer program, when executed by a processor, implements the welding control method according to any one of claims 1 to 6.

10. A computer device comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that, The processor, when executing the computer program, implements the welding control method according to any one of claims 1 to 6.

Images