Automatic welding seam tracking system based on laser vision

Abstract

The invention provides an automatic welding seam tracking system based on laser vision, 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, a deflection index calculation module, a sweep degree judgment module and a welding gun position correction value calculation module, by calculating the misalignment index of the welding track, the deviation of the welding track is found in time, it is ensured that a welding gun conducts welding along a preset path, and welding defects are reduced; the accuracy of the welding track is continuously monitored, feedback is provided, welding parameters can be adjusted in time, and the welding quality is guaranteed; according to the welding track misalignment index, the state of the welding track is judged, welding parameters are optimized, and the welding efficiency and quality are improved; the position of the welding gun can be accurately controlled by calculating the deflection index of the welding gun according to the welding track state signal, and the welding quality problem caused by deflection of the welding gun is reduced.

Description

Technical Field

[0001] The invention relates to an automatic welding seam tracking system based on laser vision, 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 weld automatic tracking systems is growing. Welding is a key process widely used in modern manufacturing, especially in the fields of automobiles, aviation, shipbuilding, pipelines, etc. However, the traditional welding process is often affected by the changes in the position, shape and angle of the weld, resulting in unstable welding quality, and even offset, missed welding or over-welding problems. In order to improve welding accuracy, automatic tracking of welds has become a research hotspot.

[0003] At present, most weld tracking systems use cameras or sensors to monitor the welding trajectory, but these systems are easily affected by temperature, smoke, and light factors in complex working environments and welding processes, resulting in reduced monitoring accuracy. 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.

[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 weak capabilities in identifying and handling problems that may arise during the welding process (such as welding gun deflection, welding trajectory inaccuracy, etc.), and often requires shutdown for 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 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 state judgment module judges whether the welding track meets the welding requirements according to the welding track misalignment index and generates a welding track state signal;

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

[0011] The welding gun position status judgment module judges whether the welding gun position is abnormal according to the welding gun deflection index and generates a welding gun position status signal;

[0012] The offset index calculation module calculates the offset index of the welding gun moving path curve and the welding trajectory curve according to the welding trajectory curve segment and the welding gun moving path curve segment;

[0013] The impact degree judgment module judges the connection between the welding gun moving path and the welding track according to the offset index, and generates an impact degree signal between the welding gun moving path and the welding track;

[0014] 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.

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

[0016] 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;

[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 cycle, dividing the welding path curve into several segments according to the distance the welding trajectory value moves within the detection cycle, 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 value is less than or equal to the welding error value δ, the welding trajectory curve segment is marked as a 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 of misaligned curve segments of the welding trajectory n i , the ratio of the number of welding trajectory misalignment curve segments to the total number of welding trajectory curve segments n is calculated to 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 indicates the welding trajectory misalignment ratio, G c It indicates 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 It is compared 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; the calculation process of the welding gun deflection index calculation module is:

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

[0040] The welding gun moving path curve is divided into several segments according to the moving distance of the welding trajectory value within the detection cycle, and the coordinate value of each welding gun moving path curve segment in the welding gun moving 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 curve segment of the welding gun moving path. 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 moving 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 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 moving path curve segment is marked as a welding gun moving path matching curve segment;

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

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

[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; through the formula:

[0050] Z p =Q s ×j w +Q z × 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 in the following manner:

[0053] Get the welding gun deflection index Z p , set the welding gun deflection index Z p comparing with a 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 that the welding gun deflection index Z p The smaller it is, the more normal the welding gun position state 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 moving 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 in the following manner:

[0063] Obtain a deviation index, and compare 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 signal of the degree of influence 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 value 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, which can timely detect the deviation of the welding trajectory by calculating the welding trajectory misalignment index, ensure that the welding gun welds along the predetermined path, and reduce welding defects; continuously monitor the accuracy of the welding trajectory and provide feedback, which helps to adjust the welding parameters in time and ensure the welding quality;

[0072] Welding track misalignment index, judge the state 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] The welding gun deflection index can monitor the welding gun position status to carry out preventive maintenance in advance and reduce the downtime caused by abnormal welding gun position;

[0075] The welding trajectory curve segment and the welding gun moving path curve segment are used to calculate the offset index between the welding gun moving path curve and the welding trajectory curve, and to evaluate the offset degree between the welding gun moving path and the welding trajectory;

[0076] The deviation index determines the connection between the welding gun moving path and the welding trajectory, and generates a signal of the degree of influence between the welding gun moving 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 It is a module block diagram of the laser vision-based weld seam automatic tracking system provided by the present invention;

[0079] Figure 2 It is a flow chart of the laser vision-based weld 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 present invention will be further described in detail below through embodiments and in conjunction with the accompanying drawings.

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

[0084] The welding trajectory misalignment index calculation module is used to obtain the weld information data during the welding process and calculate the welding trajectory misalignment index. The weld information data includes a welding trajectory value and a weld path value. The calculation process of the welding trajectory misalignment index calculation module is as follows:

[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] Obtain the welding trajectory value during the welding process (the welding trajectory value is the coordinate data of the laser moving trajectory on the weld during the welding process), substitute the welding trajectory value into the coordinate system, and generate a welding trajectory curve;

[0087] Substitute the weld path value (the weld path value is the path coordinate data required for welding the welding object) into the coordinate system to generate a weld path curve;

[0088] A detection cycle is set, and the welding 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 path curve segment in the welding path curve is obtained (the coordinate value of the welding trajectory curve segment represents the coordinate value of the midpoint of the welding trajectory curve segment);

[0089] By formula:

[0090]

[0091] Calculate the relative distance L between the welding trajectory curve segment and the corresponding weld path curve segment X Relative distance value L X The coordinate value of the welding trajectory curve segment selected by the calculation formula and the coordinate value of the weld path curve segment are within the same detection cycle, that is, the two need to be in a corresponding relationship. If the weld path curve segment has no corresponding welding trajectory curve segment, the calculation is considered to be completed until there is a new welding trajectory curve segment coordinate value);

[0092] 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;

[0093] All relative distance values ​​L X Perform mean calculation to obtain the relative distance mean;

[0094] Then the relative distance mean and 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) are calculated to obtain the welding trajectory misalignment value G c .

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

[0096] 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;

[0097] Get the number of misaligned curve segments of the welding trajectory n i , the ratio of the number of welding trajectory misalignment curve segments to the total number of welding trajectory curve segments n is calculated to obtain the welding trajectory misalignment ratio value G s ;

[0098] 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 ;

[0099] By formula:

[0100]

[0101] Calculate the welding trajectory misalignment index Z s ;

[0102] Among them, G s It indicates the welding trajectory misalignment ratio, G c It indicates the degree of welding trajectory misalignment, k c 、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 requirements according to the welding trajectory misalignment index and generates a welding trajectory state signal; 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 as follows:

[0104] Get the welding trajectory misalignment index Z s , the welding trajectory misalignment index Z s It is compared 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;

[0105] 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;

[0106] If the welding trajectory misalignment index Z s If it is greater than the welding trajectory misalignment warning ring number, it means the welding trajectory misalignment index Z s The larger the value, the more abnormal the welding trajectory is, and the less it meets the welding requirements, thus generating a welding trajectory misalignment signal.

[0107] The welding gun deflection index calculation module obtains the welding gun position data according to the welding trajectory state signal and calculates the welding gun deflection index; the welding gun position data includes the welding gun movement path value; the calculation process of the welding gun deflection index calculation module is:

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

[0109] The welding gun moving path curve is divided into several segments according to the distance moved by the welding trajectory value within the detection period, and the coordinate value of each welding gun moving path curve segment in the welding gun moving path curve is obtained (the coordinate value of the welding gun moving path curve segment represents the coordinate value of the midpoint of the welding gun moving path curve segment); through the formula:

[0110]

[0111] Calculate the difference L between the welding gun moving path curve segment and the corresponding weld path curve segment Q (Input and output value L Q The coordinates of the welding gun moving path curve segment and the weld path curve segment selected by the calculation formula should be in the same detection cycle, that is, the two need to be in a corresponding relationship. If the weld path curve segment does not have a corresponding welding gun moving path curve segment, the calculation is considered to be completed until there is a new welding gun moving path curve segment coordinate value);

[0112] Among them, X m It represents the X-axis coordinate value of the coordinate in the curve segment of the welding gun moving path. 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 moving 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 entry and exit state value is obtained by calculating the ratio with the entry and exit threshold (the entry and exit threshold 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 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 moving path curve segment is marked as a welding gun moving path matching curve segment;

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

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

[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; through the formula:

[0119] Z p =Q s ×j w +Q z × 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 state judgment module judges whether the position of the welding gun is abnormal according to the welding gun deflection index and generates a welding gun position state signal; the welding gun position state signal includes a welding gun position normal signal and a welding gun position abnormal signal; the judgment method of the welding gun position state judgment module is:

[0122] Get the welding gun deflection index Z p , set the welding gun deflection index Z p The welding gun deflection index threshold (the method of obtaining the welding gun deflection index threshold 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 moving path from the curve segment is set, and then the welding gun deflection index Z 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 paper) for comparison;

[0123] If the welding gun deflection index Z p Less than or equal to the welding gun deflection index threshold, indicating that the welding gun deflection index Z p The smaller it is, the more normal the welding gun position state 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 of the welding gun moving path curve and the welding trajectory curve according to the welding trajectory curve segment and the welding gun moving 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 moving 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 calculated by ratioing the offset error value (the offset error value refers to the offset value generated by the welding gun position during the welding process and the actual path after welding) to obtain the offset index.

[0131] The impact degree judgment module judges the connection between the moving path of the welding gun and the welding track according to the offset index, and generates an impact degree signal between the moving path of the welding gun and the welding track; the impact degree signal includes a strong impact degree signal and a weak impact degree signal; the judgment method of the impact degree judgment module is:

[0132] Obtain a deviation index, and compare 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 signal of the degree of influence 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:

[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 value of all detection cycles, and α represents the influence coefficient between the welding gun movement path curve and the welding trajectory curve.

[0140] When receiving the welding gun position correction value L 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 state judgment module judges whether the welding track meets the welding requirements according to the welding track misalignment index and generates a welding track state signal; The welding gun deflection index calculation module obtains the welding gun position data according to the welding trajectory state signal and calculates the welding gun deflection index; The welding gun position status judgment module judges whether the welding gun position is abnormal according to the welding gun deflection index and generates a welding gun position status signal; The offset index calculation module calculates the offset index of the welding gun moving path curve and the welding trajectory curve according to the welding trajectory curve segment and the welding gun moving path curve segment; The impact degree judgment module judges the connection between the welding gun moving path and the welding track according to the offset index, and generates an impact degree signal between the welding gun moving path and the welding track; 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.

2. The laser vision-based weld seam automatic tracking system according to claim 1 is characterized in that: The calculation process of the welding trajectory misalignment index calculation module is as follows: 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; 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 cycle, dividing the welding path curve into several segments according to the distance the welding trajectory value moves within the detection cycle, 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 is 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 value is less than or equal to the welding error value δ, the welding trajectory curve segment is marked as a 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 , the ratio of the number of welding trajectory misalignment curve segments to the total number of welding trajectory curve segments n is calculated to 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 indicates the welding trajectory misalignment ratio, G c It indicates 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 is characterized in that: The welding track state signal includes a welding track coincidence signal and a welding track misalignment signal; the judgment process of the welding state judgment module is as follows: Get the welding trajectory misalignment index Z s , the welding trajectory misalignment index Z s It is compared 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 it is greater than the welding trajectory misalignment warning ring number, it means the welding trajectory misalignment index Z s The larger the value, the more abnormal the welding trajectory is, and the less it meets the welding requirements, thus generating a welding trajectory misalignment signal.

5. The laser vision-based weld seam automatic tracking system according to claim 1 is characterized in that: The welding gun position data includes the welding gun moving path value; the calculation process of the welding gun deflection index calculation module is: Obtain the welding gun moving path value, substitute the welding gun moving path value into the coordinate system, and generate the welding gun moving path curve; The welding gun moving path curve is divided into several segments according to the moving distance of the welding trajectory value within the detection cycle, and the coordinate value of each welding gun moving path curve segment in the welding gun moving 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 curve segment of the welding gun moving path. 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 moving path. 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 is characterized in that: The input 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 moving path curve segment is marked as a welding gun moving path matching curve segment; If the input value L q If the value is greater than the threshold, the welding gun moving path curve segment is marked as a welding gun moving path deviation curve segment; Obtain the number of curve segments that the welding gun moving path deviates from, calculate the ratio of the number of curve segments that the welding gun moving path deviates from to the total number of curve segments of the welding gun moving path, and obtain a deviation ratio value of the welding gun moving path; 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; through the formula: 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 is 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 welding gun position status in the following manner: Get the welding gun deflection index Z p , set the welding gun deflection index Z p comparing with a 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 that the welding gun deflection index Z p The smaller it is, the more normal the welding gun position state 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 is characterized in that: The calculation process of the offset index calculation module is: Get the welding trajectory curve segment and the welding gun moving 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: Obtain a deviation index, and compare 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 signal of the degree of influence 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 value 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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