A laser vision-based automatic seam tracking system

Abstract

The application provides a laser vision-based automatic weld tracking system, which comprises a welding track misalignment index calculation module, a welding state judgment module, a welding gun deflection index calculation module, a welding gun position state judgment module, an offset index calculation module, a wave spread degree judgment module and a welding gun position correction value calculation module, calculates the welding track misalignment index, discovers the deviation of the welding track in time, ensures that the welding gun welds along the predetermined path, and reduces welding defects; continuously monitors the accuracy of the welding track and provides feedback, which helps to timely adjust the welding parameters and ensure the welding quality; the welding track misalignment index judges the state of the welding track, optimizes the welding parameters, and improves the welding efficiency and quality; the welding track state signal calculates the welding gun deflection index, which can accurately control the position of the welding gun and reduce the welding quality problems caused by the deflection of the welding gun.

Description

Technical Field

[0001] The invention relates to a laser vision-based weld automatic tracking system, in particular to the technical field of welding. Background Art

[0002] With the rapid development of industrial production and the continuous improvement of safety awareness, the demand for efficient and reliable automatic weld tracking systems is growing. Welding is a key process widely used in modern manufacturing, especially in the automotive, aviation, shipbuilding, pipeline and other fields. However, the traditional welding process is often affected by the changes in weld position, shape and angle, resulting in unstable weld quality and even offset, missed welds or over-welding problems. To improve welding accuracy, automatic weld tracking has become a research hotspot.

[0003] Currently, most seam tracking systems use cameras or sensors to monitor the weld trajectory. However, these systems are susceptible to temperature, smoke, and light factors in complex working environments and during the welding process, resulting in reduced monitoring accuracy. In traditional welding processes, the inability to accurately monitor weld information leads to deviations in the weld trajectory, affecting weld quality and accuracy.

[0004] Currently, many welding systems still rely on manual operation or simple automated equipment, lack intelligent weld tracking and adjustment mechanisms, and cannot respond to problems that arise during the welding process in a timely manner.

[0005] The welding system has a weak ability to identify and handle problems that may arise during the welding process (such as welding gun deflection, welding trajectory inaccuracy, etc.), and often requires shutdown inspection, which increases production costs. Therefore, there is an urgent need for a system that can improve the accuracy of automatic weld tracking. Summary of the Invention

[0006] Purpose of the invention: To propose a laser vision-based weld seam automatic tracking system to solve the above-mentioned problems existing in the prior art.

[0007] Technical solution: A laser vision-based weld seam automatic tracking system, including:

[0008] A welding trajectory misalignment index calculation module is used to obtain weld information data during the welding process and calculate the welding trajectory misalignment index, wherein the weld information data includes a welding trajectory value and a weld path value;

[0009] The welding status judgment module determines whether the welding trajectory meets the welding requirements based on the welding trajectory misalignment index and generates a welding trajectory status signal;

[0010] The welding gun deflection index calculation module obtains the welding gun position data according to the welding trajectory status signal and calculates the welding gun deflection index;

[0011] The welding gun position status judgment module determines whether the welding gun position is abnormal based on the welding gun deflection index and generates a welding gun position status signal;

[0012] An offset index calculation module calculates an offset index between a welding gun moving path curve and a welding trajectory curve according to the welding trajectory curve segment and the welding gun moving path curve segment;

[0013] The spread degree judgment module judges the connection between the welding gun movement path and the welding trajectory according to the offset index, and generates a spread degree signal between the welding gun movement path and the welding trajectory;

[0014] The welding gun position correction value calculation module calculates the welding gun position correction value based on the current relative distance value and the input and output values.

[0015] In a further embodiment, the calculation process of the welding trajectory misalignment index calculation module is:

[0016] First, establish a coordinate system with the length of the welding object as the X axis and the width of the welding object as the Y axis;

[0017] Obtain the welding trajectory value during the welding process, substitute the welding trajectory value into the coordinate system, and generate a welding trajectory curve;

[0018] Substitute the weld path value into the coordinate system to generate the weld path curve;

[0019] Setting a detection period, dividing the welding path curve into several segments according to the distance the welding trajectory value moves within the detection period, and obtaining the coordinate value of each welding path curve segment in the welding path curve;

[0020] By formula:

[0021]

[0022] Calculate the relative distance L between the welding trajectory curve segment and the corresponding weld path curve segment X ;

[0023] Among them, X n It represents the X-axis coordinate value of the coordinate in the welding trajectory curve segment. i It represents the X-axis coordinate value of the coordinate in the weld path curve segment, n It represents the Y-axis coordinate value of the coordinate in the welding trajectory curve segment. i It represents the Y-axis coordinate value of the coordinate in the weld path curve segment, n represents the number of weld trajectory curve segments, and i represents the number of weld path curve segments;

[0024] All relative distance values ​​L X Perform mean calculation to obtain the relative distance mean;

[0025] Then the ratio of the relative distance mean to the welding error value δ is calculated to obtain the welding trajectory misalignment value G c .

[0026] In a further embodiment, the relative distance value L X Compared with the welding error value δ, if the relative distance value L X If the error is less than or equal to the welding error value δ, the welding trajectory curve segment is marked as the welding trajectory matching curve segment;

[0027] If the relative distance value L X If the error is greater than the welding error value δ, the welding trajectory curve segment is marked as a welding trajectory misalignment curve segment;

[0028] Get the number n of misaligned curve segments of the welding trajectory i , calculate the ratio of the number of welding trajectory misalignment curve segments to the total number of welding trajectory curve segments n, and obtain the welding trajectory misalignment ratio value G s ;

[0029] The welding trajectory misalignment ratio G s Misalignment value with welding trajectory G c Perform weighted averaging to calculate the welding trajectory misalignment index Z s ;

[0030] By formula:

[0031]

[0032] Calculate the welding trajectory misalignment index Z s ;

[0033] Among them, G s It represents the welding trajectory misalignment ratio value, G c It represents the degree of welding trajectory misalignment, k c 、c t are weight coefficients, and k c +c t =1.

[0034] In a further embodiment, the welding trajectory state signal includes a welding trajectory coincidence signal and a welding trajectory misalignment signal; the judgment process of the welding state judgment module is:

[0035] Get the welding trajectory misalignment index Z s , the welding trajectory misalignment index Z s Compare with the welding trajectory misalignment warning ring number, the welding trajectory misalignment warning ring number is a preset value, and its calculation method is the same as the welding trajectory misalignment index Z sThe calculation is the same as that of X and the number ni of misaligned curve segments of the welding trajectory;

[0036] If the welding trajectory misalignment index Z s Less than or equal to the welding trajectory misalignment warning ring number, indicating the welding trajectory misalignment index Z s The smaller it is, the less abnormal the welding trajectory is, and the more it meets the welding requirements, and a welding trajectory matching signal is generated;

[0037] If the welding trajectory misalignment index Z s If the value is greater than the welding trajectory misalignment warning ring, the larger the welding trajectory misalignment index Z is, the greater the degree of abnormality of the welding trajectory is, and the less it meets the welding requirements, then a welding trajectory misalignment signal is generated.

[0038] In a further embodiment, the welding gun position data includes a welding gun movement path value; and the calculation process of the welding gun deflection index calculation module is:

[0039] Obtain the welding gun movement path value, substitute the welding gun movement path value into the coordinate system, and generate the welding gun movement path curve;

[0040] The welding gun movement path curve is divided into several segments according to the distance the welding trajectory value moves within the detection cycle, and the coordinate value of each welding gun movement path curve segment in the welding gun movement path curve is obtained; through the formula:

[0041]

[0042] Calculate the difference L between the welding gun moving path curve segment and the corresponding weld path curve segment Q ;

[0043] Among them, X m It represents the X-axis coordinate value of the coordinate in the welding gun moving path curve segment. i It represents the X-axis coordinate value of the coordinate in the weld path curve segment, m It represents the Y-axis coordinate value of the coordinate in the curve segment of the welding gun movement path. i It represents the Y-axis coordinate value of the coordinate in the weld path curve segment;

[0044] All the input and output values ​​L Q Perform mean calculation to obtain the input and output mean ΔL Q ;

[0045] Then the input and output mean ΔL Q The ratio is calculated with the entry and exit threshold to obtain the welding gun entry and exit status value.

[0046] In a further embodiment, the input value L QCompare with the entry and exit thresholds. If the entry and exit values ​​L Q If the value is less than or equal to the threshold, the welding gun movement path curve segment is marked as a welding gun movement path matching curve segment;

[0047] If the input and output value L Q If the value is greater than the threshold, the welding gun movement path curve segment is marked as a welding gun movement path deviation curve segment;

[0048] Obtain the number of curve segments that the welding gun movement path deviates from, calculate the ratio of the number of curve segments that the welding gun movement path deviates from to the total number of curve segments of the welding gun movement path, and obtain a welding gun movement path deviation ratio;

[0049] The welding gun movement path deviation ratio value and the welding gun in and out state value are weighted and summed to calculate the welding gun deflection index; the formula is:

[0050] Z p =Q s ×j w +Q z ×w e

[0051] Calculate the welding gun deflection index Z p Among them, Q s It represents the deviation ratio of the welding gun moving path, Q z It indicates the welding gun in and out status value, j w 、w e are weight coefficients, and j w +w e =1.

[0052] In a further embodiment, the welding gun position status signal includes a welding gun position normal signal and a welding gun position abnormal signal; the welding gun position status judgment module judges the welding gun position status in the following manner:

[0053] Get the welding gun deflection index Z p , set the welding gun deflection index Z p comparing with the welding gun deflection index threshold;

[0054] If the welding gun deflection index Z p Less than or equal to the welding gun deflection index threshold, indicating the welding gun deflection index Z p The smaller it is, the more normal the welding gun position status is, and a normal welding gun position signal is generated;

[0055] If the welding gun deflection index Z p Greater than the welding gun deflection index threshold, indicating that the welding gun deflection index Z p The larger the value, the more abnormal the welding gun position state is, and a welding gun position abnormality signal is generated.

[0056] In a further embodiment, the calculation process of the offset index calculation module is:

[0057] Get the welding trajectory curve segment and the welding gun movement path curve segment; through the formula:

[0058]

[0059] Calculate the offset value X between the welding gun moving path curve segment and the welding trajectory curve segment S ;

[0060] Set all offset values ​​X S Perform mean calculation to obtain the offset mean;

[0061] Then the ratio of the offset mean value to the offset error value is calculated to obtain the offset index.

[0062] In a further embodiment, the impact degree signal includes a strong impact degree signal and a weak impact degree signal; the impact degree determination module determines the impact degree by:

[0063] Obtaining a deviation index, and comparing the deviation index with a deviation index threshold, wherein the deviation index threshold is set to 1;

[0064] If the offset index is less than or equal to 1, it means that the lower the offset index is, the higher the similarity between the welding gun movement path curve and the welding trajectory curve is, and a strong sweep signal is generated;

[0065] If the offset index is greater than 1, it means that the higher the offset index is, the lower the similarity between the welding gun movement path curve and the welding trajectory curve is, and a weak sweep signal is generated.

[0066] In a further embodiment, the calculation process of the welding gun position correction value calculation module is:

[0067] Get the current relative distance value L xi , through the formula:

[0068] L J =L xi -L h ×α

[0069] Calculate the welding gun position correction value L j ;

[0070] Among them, L xi Indicates the current relative distance value, L h It represents the average value of the relative distance values ​​of all detection cycles, and α represents the influence coefficient between the welding gun movement path curve and the welding trajectory curve.

[0071] Beneficial effects: The present invention proposes an automatic weld tracking system based on laser vision. By calculating the welding trajectory misalignment index, the system can promptly detect welding trajectory deviations, ensure that the welding gun welds along the predetermined path, and reduce welding defects. The system continuously monitors the accuracy of the welding trajectory and provides feedback, which helps to adjust welding parameters in a timely manner to ensure welding quality.

[0072] Welding track misalignment index, judge the status of welding track, optimize welding parameters, and improve welding efficiency and quality;

[0073] The welding trajectory status signal calculates the welding gun deflection index, which can accurately control the position of the welding gun and reduce welding quality problems caused by welding gun deflection;

[0074] Welding gun deflection index, by monitoring the welding gun position status, can be used for preventive maintenance in advance, reducing downtime caused by abnormal welding gun position;

[0075] Welding trajectory curve segment and welding gun movement path curve segment, calculate the offset index of welding gun movement path curve and welding trajectory curve, and evaluate the offset degree between welding gun movement path and welding trajectory;

[0076] The deviation index determines the connection between the welding gun movement path and the welding trajectory, and generates a confluence degree signal between the welding gun movement path and the welding trajectory;

[0077] According to the current relative distance value and the input and output values, the welding gun position correction value is calculated and the position of the welding gun is adjusted. By calculating the welding gun position correction value, the position of the welding gun can be dynamically adjusted to ensure that the welding gun is always in the optimal welding position. BRIEF DESCRIPTION OF THE DRAWINGS

[0078] Figure 1 This is a module block diagram of the laser vision-based weld automatic tracking system provided by the present invention;

[0079] Figure 2 This is a flow chart of the laser vision-based weld seam automatic tracking system provided by the present invention. DETAILED DESCRIPTION

[0080] The applicant believes that in the traditional welding process, due to the inability to accurately monitor weld information, the welding trajectory is prone to deviations, affecting the quality and accuracy of welding. Currently, many welding systems still rely on manual operation or simple automated equipment, lack intelligent weld tracking and adjustment mechanisms, and cannot respond to problems that arise during the welding process in a timely manner.

[0081] In order to solve the problems existing in the prior art, the present invention continuously monitors the accuracy of the welding trajectory through an automatic weld tracking system based on laser vision.

[0082] The application will be further described in detail below with reference to the embodiments and the accompanying drawings.

[0083] In this application, we propose a laser vision-based automatic weld tracking system, comprising:

[0084] A welding trajectory misalignment index calculation module is configured to obtain weld information data in the welding process, and calculate a welding trajectory misalignment index, wherein the weld information data comprises welding trajectory values and weld path values.

[0085] First, a coordinate system is established with the length of the welding object as the X-axis and the width of the welding object as the Y-axis.

[0086] Welding trajectory values (which are coordinate data of the welding trajectory of the laser on the weld during the welding process) are obtained, and the welding trajectory values are substituted into the coordinate system to generate a welding trajectory curve.

[0087] Weld path values (which are path coordinate data of the welding object to be welded) are substituted into the coordinate system to generate a weld path curve.

[0088] A detection period is set, and the welding path curve is divided into several segments according to the distance moved by the welding trajectory values within the detection period, and the coordinate values of each welding path curve segment in the welding path curve (which represent the coordinate values of the midpoint of the welding trajectory curve segment) are obtained.

[0089] The relative distance value L between the welding trajectory curve segment and the corresponding weld path curve segment is calculated by the formula:

[0090]

[0091] The relative distance value L between the welding trajectory curve segment and the corresponding weld path curve segment is calculated by the formula: X The relative distance value L between the welding trajectory curve segment and the corresponding weld path curve segment is calculated by the formula: X The coordinate values of the welding trajectory curve segment and the weld path curve segment are selected within the same detection period, i.e., they need to be in a corresponding relationship. If there is no corresponding welding trajectory curve segment for the weld path curve segment, the calculation is considered complete, and a new welding trajectory curve segment coordinate value is obtained.

[0092] Wherein, X n represents the X-axis coordinate value of the coordinate in the welding trajectory curve segment, X i represents the X-axis coordinate value of the coordinate in the weld path curve segment, Y n represents the Y-axis coordinate value of the coordinate in the welding trajectory curve segment, and Y i represents the Y-axis coordinate value of the coordinate in the weld path curve segment, n represents the number of welding trajectory curve segments, and i represents the number of weld path curve segments.

[0093] All the relative distance values L X The mean value is calculated to obtain the relative distance mean value;

[0094] The relative distance mean value is compared with the welding error value δ (the welding error value δ represents the maximum error distance that does not affect the welding quality during the welding process) to obtain the welding trajectory misalignment degree value G c .

[0095] The relative distance value L X is compared with the welding error value δ, if the relative distance value L X is less than or equal to the welding error value δ, the welding trajectory curve segment is marked as a welding trajectory fitting curve segment;

[0096] If the relative distance value L X is greater than the welding error value δ, the welding trajectory curve segment is marked as a welding trajectory misalignment curve segment;

[0097] The number n i of the welding trajectory misalignment curve segments is obtained, and the number of the welding trajectory misalignment curve segments is compared with the total number n of the welding trajectory curve segments to obtain the welding trajectory misalignment proportion value G s ;

[0098] The welding trajectory misalignment proportion value G s is compared with the welding trajectory misalignment degree value G c , and the weighted mean value is calculated to obtain the welding trajectory misalignment index Z s ;

[0099] The welding trajectory misalignment index Z s is calculated by the formula:

[0100]

[0101] The welding trajectory misalignment index Z s ;

[0102] Wherein, G s represents the welding trajectory misalignment proportion value, G c represents the welding trajectory misalignment degree value, k c and c t are weight coefficients, and k c +c t =1.

[0103] The welding state judgment module judges whether the welding trajectory meets the welding requirement according to the welding trajectory misalignment index, and generates a welding trajectory state signal; the welding trajectory state signal includes a welding trajectory fitting signal and a welding trajectory misalignment signal; the judgment process of the welding state judgment module is:

[0104] acquire the welding trajectory misalignment index Z s , compare the welding trajectory misalignment index Z s with the welding trajectory misalignment warning index, and the welding trajectory misalignment warning index is a preset value, and the calculation method is the same as that of the welding trajectory misalignment index Z s , and only the values of the relative distance value L X and the number n i of the welding trajectory misalignment curve segments need to be set.

[0105] If the welding trajectory misalignment index Z s is less than or equal to the welding trajectory misalignment warning index, it indicates that the smaller the welding trajectory misalignment index Z s is, the smaller the welding trajectory abnormality degree is, and the more in line with the welding requirements, and then a welding trajectory fitting signal is generated.

[0106] If the welding trajectory misalignment index Z s is greater than the welding trajectory misalignment warning index, it indicates that the greater the welding trajectory misalignment index Z s is, the greater the welding trajectory abnormality degree is, and the more not in line with the welding requirements, and then a welding trajectory misalignment signal is generated.

[0107] The welding torch deflection index calculation module acquires welding torch position data according to the welding trajectory state signal, and calculates a welding torch deflection index; the welding torch position data includes a welding torch movement path value; the calculation process of the welding torch deflection index calculation module is as follows:

[0108] Acquire the welding torch movement path value (the welding torch movement path value represents the path information generated by the movement of the laser emitter, and the laser emitter is installed on the welding torch and moves synchronously with the welding torch, that is, the welding torch movement path is equal to the movement trajectory of the starting point of the laser point), and substitute the welding torch movement path value into the coordinate system to generate a welding torch movement path curve.

[0109] Divide the welding torch movement path curve into several segments according to the distance of the welding trajectory value movement in the detection period, and acquire the coordinate value of each welding torch movement path curve segment in the welding torch movement path curve (the coordinate value of the welding torch movement path curve segment represents the coordinate value of the midpoint of the welding torch movement path curve segment); calculate the welding torch movement path curve segment and the corresponding welding seam path curve segment according to the formula:

[0110]

[0111] to obtain the in-out value L Q between the welding torch movement path curve segment and the corresponding welding seam path curve segment (the calculation formula of the in-out value L Q should select the coordinates of the welding torch movement path curve segment and the coordinates of the welding seam path curve segment in the same detection period, that is, the two should be in a corresponding relationship, and if the welding seam path curve segment does not have a corresponding welding torch movement path curve segment, it is considered that the calculation is complete, and until there is a new welding torch movement path curve segment coordinate value.

[0112] Among them, X m It represents the X-axis coordinate value of the coordinate in the welding gun moving path curve segment. i It represents the X-axis coordinate value of the coordinate in the weld path curve segment, m It represents the Y-axis coordinate value of the coordinate in the curve segment of the welding gun movement path. i It represents the Y-axis coordinate value of the coordinate in the weld path curve segment;

[0113] All the input and output values ​​L Q Perform mean calculation to obtain the input and output mean ΔL Q ;

[0114] Then the input and output mean ΔL Q The welding gun in-and-out state value is obtained by calculating the ratio with the in-and-out threshold value (the in-and-out threshold value represents the maximum deviation value that can occur between the welding gun position and the weld path without affecting welding during the welding process).

[0115] The input and output value L Q Compare with the input and output thresholds. If the input and output value L Q If the value is less than or equal to the threshold, the welding gun movement path curve segment is marked as a welding gun movement path matching curve segment;

[0116] If the input and output value L Q If the value is greater than the threshold, the welding gun movement path curve segment is marked as a welding gun movement path deviation curve segment;

[0117] Obtain the number of curve segments that the welding gun movement path deviates from, calculate the ratio of the number of curve segments that the welding gun movement path deviates from to the total number of curve segments of the welding gun movement path, and obtain a welding gun movement path deviation ratio;

[0118] The welding gun movement path deviation ratio value and the welding gun in and out state value are weighted and summed to calculate the welding gun deflection index; the formula is:

[0119] Z p =Q s ×j w +Q z ×w e

[0120] Calculate the welding gun deflection index Z p Among them, Q s It represents the deviation ratio of the welding gun moving path, Q z It indicates the welding gun in and out status value, j w 、w e are weight coefficients, and j w +w e =1.

[0121] The welding gun position status judgment module judges whether the welding gun position is abnormal based on the welding gun deflection index and generates a welding gun position status signal; the welding gun position status signal includes a welding gun position normal signal and a welding gun position abnormal signal; the welding gun position status judgment module judges the position of the welding gun in the following manner:

[0122] Get the welding gun deflection index Z p , set the welding gun deflection index Z p The welding gun deflection index threshold value (the method of obtaining the welding gun deflection index threshold value specifically includes: relevant personnel in this field adjust the input and output values ​​L according to welding requirements Q , the value of the number of deviations of the welding gun movement path from the curve segment is set, and then the welding gun deflection index Z is used p The calculation formula for the welding gun deflection index threshold is obtained, and the welding gun deflection index threshold is related to the welding gun deflection index Z p The calculation formula is consistent with that of the original data) for comparison;

[0123] If the welding gun deflection index Z p Less than or equal to the welding gun deflection index threshold, indicating the welding gun deflection index Z p The smaller it is, the more normal the welding gun position status is, and a normal welding gun position signal is generated;

[0124] If the welding gun deflection index Z p Greater than the welding gun deflection index threshold, indicating that the welding gun deflection index Z p The larger the value, the more abnormal the welding gun position state is, and a welding gun position abnormality signal is generated.

[0125] The offset index calculation module calculates the offset index between the welding gun movement path curve and the welding trajectory curve according to the welding trajectory curve segment and the welding gun movement path curve segment. The calculation process of the offset index calculation module is as follows:

[0126] Get the welding trajectory curve segment and the welding gun movement path curve segment; through the formula:

[0127]

[0128] Calculate the offset value X between the welding gun moving path curve segment and the welding trajectory curve segment S ;

[0129] Set all offset values ​​X S Perform mean calculation to obtain the offset mean;

[0130] The offset mean is then compared to the offset error (the offset error refers to the offset between the welding gun position and the actual welding path) to obtain the offset index.

[0131] The impact degree judgment module judges the connection between the welding gun movement path and the welding trajectory based on the offset index, and generates an impact degree signal between the welding gun movement path and the welding trajectory; the impact degree signal includes a strong impact degree signal and a weak impact degree signal; the impact degree judgment module judges the connection between the welding gun movement path and the welding trajectory based on the offset index, and generates an impact degree signal between the welding gun movement path and the welding trajectory; the impact degree judgment module judges the connection between the welding gun movement path and the welding trajectory based on the offset index ...

[0132] Obtaining a deviation index, and comparing the deviation index with a deviation index threshold, wherein the deviation index threshold is set to 1;

[0133] If the offset index is less than or equal to 1, it means that the lower the offset index is, the higher the similarity between the welding gun movement path curve and the welding trajectory curve is, and a strong sweep signal is generated;

[0134] If the offset index is greater than 1, it means that the higher the offset index is, the lower the similarity between the welding gun movement path curve and the welding trajectory curve is, and a weak sweep signal is generated.

[0135] The welding gun position correction value calculation module calculates the welding gun position correction value according to the current relative distance value and the input and output values. The calculation process of the welding gun position correction value calculation module is as follows:

[0136] Get the current relative distance value L xi , through the formula:

[0137] L J =L xi -L h ×α

[0138] Calculate the welding gun position correction value L j ;

[0139] Among them, L xi Indicates the current relative distance value, L h It represents the average value of the relative distance values ​​of all detection cycles, and α represents the influence coefficient between the welding gun movement path curve and the welding trajectory curve.

[0140] When the welding gun position correction value L is received J When the welding gun position correction value L J The control signal is sent to the control end of the welding device (the welding device performs welding according to the point position of the laser on the weld, that is, the welding trajectory is equal to the laser point motion trajectory), and the control end sends a control signal to the control end of the welding gun. The control end of the welding gun corrects the welding gun position according to the welding gun position correction value L. J Adjust the welding gun position.

[0141] As described above, although the present invention has been shown and described with reference to specific preferred embodiments, it should not be construed as limiting the present invention itself. Various changes may be made to it in form and detail without departing from the spirit and scope of the present invention as defined in the appended claims.

Claims

1. A laser vision-based weld seam automatic tracking system, characterized in that: include: A welding trajectory misalignment index calculation module is used to obtain weld information data during the welding process and calculate the welding trajectory misalignment index, wherein the weld information data includes a welding trajectory value and a weld path value; The welding status judgment module determines whether the welding trajectory meets the welding requirements based on the welding trajectory misalignment index and generates a welding trajectory status signal; The welding gun deflection index calculation module obtains the welding gun position data according to the welding trajectory status signal and calculates the welding gun deflection index; The welding gun position status judgment module determines whether the welding gun position is abnormal based on the welding gun deflection index and generates a welding gun position status signal; An offset index calculation module calculates an offset index between a welding gun moving path curve and a welding trajectory curve according to the welding trajectory curve segment and the welding gun moving path curve segment; The spread degree judgment module judges the connection between the welding gun movement path and the welding trajectory according to the offset index and generates a spread degree signal between the welding gun movement path and the welding trajectory; The welding gun position correction value calculation module calculates the welding gun position correction value based on the current relative distance value and the input and output values.

2. The laser vision-based weld seam automatic tracking system according to claim 1, characterized in that: The calculation process of the welding trajectory misalignment index calculation module is as follows: First, establish a coordinate system with the length of the welding object as the X axis and the width of the welding object as the Y axis; Obtain the welding trajectory value during the welding process, substitute the welding trajectory value into the coordinate system, and generate a welding trajectory curve; Substitute the weld path value into the coordinate system to generate the weld path curve; Setting a detection period, dividing the welding path curve into several segments according to the distance the welding trajectory value moves within the detection period, and obtaining the coordinate value of each welding path curve segment in the welding path curve; By formula: Calculate the relative distance L between the welding trajectory curve segment and the corresponding weld path curve segment X ; Among them, X n It represents the X-axis coordinate value of the coordinate in the welding trajectory curve segment. i It represents the X-axis coordinate value of the coordinate in the weld path curve segment, n It represents the Y-axis coordinate value of the coordinate in the welding trajectory curve segment. i It represents the Y-axis coordinate value of the coordinate in the weld path curve segment, n represents the number of weld trajectory curve segments, and i represents the number of weld path curve segments; All relative distance values ​​L X Perform mean calculation to obtain the relative distance mean; Then, the ratio of the relative distance mean to the welding error value δ is calculated to obtain the welding trajectory misalignment value Gc.

3. The laser vision-based weld seam automatic tracking system according to claim 2, characterized in that: The relative distance value L X Compared with the welding error value δ, if the relative distance value L X If the error is less than or equal to the welding error value δ, the welding trajectory curve segment is marked as the welding trajectory matching curve segment; If the relative distance value L X If the error is greater than the welding error value δ, the welding trajectory curve segment is marked as a welding trajectory misalignment curve segment; Get the number n of misaligned curve segments of the welding trajectory i , calculate the ratio of the number of welding trajectory misalignment curve segments to the total number of welding trajectory curve segments n, and obtain the welding trajectory misalignment ratio value G s ; The welding trajectory misalignment ratio G s Misalignment value with welding trajectory G c Perform weighted averaging to calculate the welding trajectory misalignment index Z s ; By formula: Calculate the welding trajectory misalignment index Z s ; Among them, G s It represents the welding trajectory misalignment ratio value, G c It represents the degree of welding trajectory misalignment, k c 、c t are weight coefficients, and k c +c t =1.

4. The laser vision-based weld seam automatic tracking system according to claim 1, characterized in that: The welding trajectory status signal includes a welding trajectory coincidence signal and a welding trajectory misalignment signal; the judgment process of the welding status judgment module is as follows: Get the welding trajectory misalignment index Z s , the welding trajectory misalignment index Z s Compare with the welding trajectory misalignment warning ring number, the welding trajectory misalignment warning ring number is a preset value, and its calculation method is the same as the welding trajectory misalignment index Z s The calculation is the same as that of X and the number ni of misaligned curve segments of the welding trajectory; If the welding trajectory misalignment index Z s Less than or equal to the welding trajectory misalignment warning ring number, indicating the welding trajectory misalignment index Z s The smaller it is, the less abnormal the welding trajectory is, and the more it meets the welding requirements, and a welding trajectory matching signal is generated; If the welding trajectory misalignment index Z s If the value is greater than the welding trajectory misalignment warning ring number, it indicates the welding trajectory misalignment index Z s The larger the value, the greater the abnormality of the welding trajectory, and the less it meets the welding requirements, and a welding trajectory misalignment signal is generated.

5. The laser vision-based weld seam automatic tracking system according to claim 1, characterized in that: The welding gun position data includes the welding gun movement path value; the calculation process of the welding gun deflection index calculation module is: Obtain the welding gun movement path value, substitute the welding gun movement path value into the coordinate system, and generate the welding gun movement path curve; The welding gun movement path curve is divided into several segments according to the distance the welding trajectory value moves within the detection cycle, and the coordinate value of each welding gun movement path curve segment in the welding gun movement path curve is obtained; through the formula: Calculate the difference L between the welding gun moving path curve segment and the corresponding weld path curve segment q ; Among them, X m It represents the X-axis coordinate value of the coordinate in the welding gun moving path curve segment. i It represents the X-axis coordinate value of the coordinate in the weld path curve segment, m It represents the Y-axis coordinate value of the coordinate in the welding gun moving path curve segment. i It represents the Y-axis coordinate value of the coordinate in the weld path curve segment; All the input and output values ​​L Q Perform mean calculation to obtain the input and output mean ΔL Q ; Then the input and output mean ΔL Q The ratio is calculated with the entry and exit threshold to obtain the welding gun entry and exit status value.

6. The laser vision-based weld seam automatic tracking system according to claim 5, characterized in that: The input and output value L Q Compare with the input and output thresholds. If the input and output value L Q If the value is less than or equal to the threshold, the welding gun movement path curve segment is marked as a welding gun movement path matching curve segment; If the input and output value L q If the value is greater than the threshold, the welding gun movement path curve segment is marked as a welding gun movement path deviation curve segment; Obtain the number of curve segments that the welding gun movement path deviates from, calculate the ratio of the number of curve segments that the welding gun movement path deviates from to the total number of curve segments of the welding gun movement path, and obtain a welding gun movement path deviation ratio; The welding gun movement path deviation ratio value and the welding gun entry and exit state value are weighted and summed to calculate the welding gun deflection index; the formula is: Z p =Q s ×j w +Q z ×w e Calculate the welding gun deflection index Z p Among them, Q s It represents the deviation ratio of the welding gun moving path, Q z It indicates the welding gun in and out status value, j w 、w e are weight coefficients, and j w +w e =1.

7. The laser vision-based weld seam automatic tracking system according to claim 1, characterized in that: The welding gun position status signal includes a normal welding gun position signal and an abnormal welding gun position signal; the welding gun position status judgment module judges the position of the welding gun in the following manner: Get the welding gun deflection index Z p , set the welding gun deflection index Z p comparing with the welding gun deflection index threshold; If the welding gun deflection index Z p Less than or equal to the welding gun deflection index threshold, indicating the welding gun deflection index Z p The smaller it is, the more normal the welding gun position status is, and a normal welding gun position signal is generated; If the welding gun deflection index Z p Greater than the welding gun deflection index threshold, indicating that the welding gun deflection index Z p The larger the value, the more abnormal the welding gun position state is, and a welding gun position abnormality signal is generated.

8. The laser vision-based weld seam automatic tracking system according to claim 1, characterized in that: The calculation process of the offset index calculation module is as follows: Get the welding trajectory curve segment and the welding gun movement path curve segment; through the formula: Calculate the offset value X between the welding gun moving path curve segment and the welding trajectory curve segment S ; Set all offset values ​​X S Perform mean calculation to obtain the offset mean; Then the ratio of the offset mean value to the offset error value is calculated to obtain the offset index.

9. The laser vision-based weld seam automatic tracking system according to claim 1, characterized in that: The impact degree signal includes a strong impact degree signal and a weak impact degree signal; the impact degree judgment module judges the impact degree in the following manner: Obtaining a deviation index, and comparing the deviation index with a deviation index threshold, wherein the deviation index threshold is set to 1; If the offset index is less than or equal to 1, it means that the lower the offset index is, the higher the similarity between the welding gun movement path curve and the welding trajectory curve is, and a strong sweep signal is generated; If the offset index is greater than 1, it means that the higher the offset index is, the lower the similarity between the welding gun movement path curve and the welding trajectory curve is, and a weak sweep signal is generated.

10. The laser vision-based weld seam automatic tracking system according to claim 1, characterized in that: The calculation process of the welding gun position correction value calculation module is as follows: Get the current relative distance value L xi , through the formula: L J =L xi -L h ×α Calculate the welding gun position correction value L j ; Among them, L xi Indicates the current relative distance value, L h It represents the average value of the relative distance values ​​of all detection cycles, and α represents the influence coefficient between the welding gun movement path curve and the welding trajectory curve.

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