Welding seam tracking system for tailor-welded blank welding

Abstract

The invention belongs to the technical field of plate tailor-welding, and particularly relates to a welding seam tracking system for tailor-welded blank welding, which comprises a welding line and a welding seam tracking system, the welding line comprises a manipulator, a feeding mechanism, a six-axis welding part and a plate placing part, the six-axis welding part comprises a Z axis, a laser welding head and a welding seam tracking sensor, the plate placing part comprises a base and a fixing mechanism, and the base is placed on a welding line; the fixing mechanism comprises four fixing parts and a driving cavity, each fixing part comprises a cavity, a sliding plate, a push-pull rod and a push-pull plate and is evenly arranged on the periphery of the upper portion of the base, and the welding seam tracking system comprises a laser scanning visual sensing module, an image processing module and a feedback control module. The system solves the problems that the production efficiency and the welding quality are reduced due to the fact that welding seam tracking accuracy and real-time performance cannot be achieved during current plate tailor-welding, and plates are loosened due to the fact that the plates cannot be stabilized during welding.

Description

Technical Field

[0001] The invention belongs to the technical field of plate tailor-welding, and in particular relates to a weld tracking system for tailor-welded plates. Background Art

[0002] Laser welding uses laser energy to automatically join and weld several steels, stainless steels, aluminum alloys, etc. of different materials, thicknesses, and coatings to form an integral plate, profile, sandwich panel, etc. to meet the different material performance requirements of parts and components. The welding of several plates is usually done by robots instead of manual labor to improve efficiency. Therefore, robot tracking of welds is a key technology. The welding speed of weld tracking on the market cannot be automatically adjusted, resulting in low welding efficiency. In addition, after several plates are spliced ​​together, the weld needs to be fixed. Otherwise, the weld will be too large and the welding will be unstable. This phenomenon has become a problem that needs to be urgently solved by people in this field. Summary of the invention

[0003] The object of the present invention is to provide a weld tracking system for tailor-welded blanks to solve the problems raised in the above-mentioned background technology.

[0004] In order to solve the above technical problems, the present invention provides the following technical solutions: a weld tracking system for tailor-welded plate welding, comprising a welding line and a weld tracking system, the welding line comprising a manipulator, a feeding mechanism, a six-axis welding part and a plate placement part, the six-axis welding part comprising a Z-axis, a laser welding head and a weld tracking sensor, the plate placement part comprising a base and a fixing mechanism, the base being placed on the welding line; the fixing mechanism comprising four fixing parts and a driving cavity, the four fixing parts each comprising a chamber, a slide plate, a push-pull rod and a push-pull plate, and being evenly arranged around the top of the base, the weld tracking system comprising a laser scanning visual sensing module, an image processing module and a feedback control module, the laser scanning visual sensing module being used to track the weld The tracking sensor captures the real-time image of the weld and calibrates it using the triangulation principle to obtain the shape and position information of the weld. The image processing module is used to identify the position and shape of the weld through image processing technology, edge detection and template matching algorithm, so as to calculate the height and Y-direction deviation to determine the specific position and shape deviation of the weld. The feedback control module is used to generate a control signal according to the identified weld position, and adjust the motion trajectory of the Z axis in real time to maintain the accuracy of the weld. The weld tracking sensor is used to calculate the movement route of the laser welding head through the laser triangulation method, wherein the laser triangulation method calculates the distance by measuring the angle change of the laser pulse after it is reflected on the target object; the tracking algorithm of the laser triangulation method is: Where D is the distance between the weld and the laser and receiver, i.e. the depth to be measured, F is the focal length of the receiving lens, L is the offset between the optical axis of the transmitting light path and the main optical axis of the receiving lens, i.e. the baseline distance, and d is the position offset above the receiving CCD detector.

[0005] The present invention further illustrates that the Z-axis is installed on the welding line, the laser welding head and the weld tracking sensor are fixedly installed on the Z-axis; the chamber is fixedly installed above the base, the slide is slidably connected to the inner wall of the chamber, the push-pull plate is fixedly connected to the slide through a push-pull rod, an annular tube is connected between the outer ends of the four chambers, a driving part is provided inside the driving chamber, and an air pipe is connected between the driving part and the annular tube; the welding steps of the welding machine include: step S1, the manipulator grabs the plate and puts several plates between the push-pull plates through the feeding mechanism, and splices them together, and then produces a Generate gas pressure, and the gas enters the annular tube through the gas pipe and finally enters the chamber to fix the plate and limit the plate; step S2, the Z axis runs, driving the laser welding head and the weld tracking sensor to move synchronously, the weld tracking sensor is aligned with the weld, and the real-time image of the weld is captured by the weld tracking sensor to obtain the shape and position information of the weld, and then determine the specific position and shape deviation of the weld, and finally adjust the movement trajectory of the Z axis in real time according to the identified weld position, and weld the weld; step S3, during the welding process, adjust the weld tracking speed, so as to track the welding in real time and complete the welding of several plates.

[0006] The present invention further illustrates that in step S3, the welding seam tracking speed is adjusted as follows: Among them, V is the weld tracking speed, L is the weld length, D is the wire diameter, R is the welding current, and Q is the welding coefficient, which depends on the specific welding process and equipment and is usually between 0.8 and 0.9.

[0007] The present invention further illustrates that the driving part includes a motor, a connecting shaft, a shaft rod, a gear and a pneumatic chamber; the motor is fixedly installed on the front side of the inner wall of the driving chamber, the connecting shaft is fixedly connected to the output end of the motor, the gear is connected to the bearing on the rear side of the inner wall of the driving chamber, and is connected to the connecting shaft through the shaft rod, the inner wall of the pneumatic chamber is slidably connected with a pneumatic plate, a tooth plate is fixedly installed on the left side of the pneumatic plate, and the tooth plate and the lower part of the gear are meshed with each other, and the pneumatic chamber is connected to the trachea pipeline; the weld tracking system also includes a plate quantity identification module and an intelligent control module, the quantity identification module is arranged inside the weld tracking sensor, and is electrically connected to the intelligent control module, the intelligent control module is electrically connected to the motor, the plate quantity identification module is used to identify the number of plates through the weld tracking sensor, and the intelligent control module is used to control the torque of the motor according to the number of plates.

[0008] The present invention further illustrates that a hollow cavity is fixedly installed at the bottom of the inner wall of the driving cavity, a cylinder is fixedly installed at the bottom of the inner wall of the hollow cavity, a reciprocating rod is fixedly connected to the output end of the cylinder, and a strong magnet is fixedly installed on the upper end of the reciprocating rod; a notch is provided at the rear end of the connecting shaft, a plurality of slots are provided in the inner circle of the notch, a boss is provided at the front end of the shaft rod, and the boss is inserted into the notch, a block is connected to a side axis of the boss, a spring is connected between the block and the outer surface of the boss, the block is clamped in the slot, and is located directly above the strong magnet, the block is magnetic, and the magnetic pole is the same as the strong magnet.

[0009] The present invention further describes that an undulating plate is fixedly installed on the outer side of the reciprocating rod, and the undulating plate is slidably connected to the inner wall of the hollow cavity, and the upper part of the hollow cavity is connected to the right pipe of the air pressure cavity.

[0010] The present invention further illustrates that a sliding hole is arranged above the hollow cavity, and a limit rod is slidably connected to the inner wall of the sliding block, a limit block is fixed on the outer side of the limit rod, and an elastic spring is arranged between the limit block and the outer wall above the hollow cavity; a telescopic joint is fixedly installed below the left end of the tooth plate, the telescopic joint is connected to the left hose of the air pressure chamber, and a pressure valve is arranged in the hose, the left side of the air pressure chamber is connected to the external pipeline, and a one-way valve is arranged in the pipeline, the left side of the telescopic joint is connected to the external control valve hose, the upper end of the limit rod and the lower end of the telescopic joint are both spherical and aligned with each other.

[0011] Compared with the prior art, the beneficial effects achieved by the present invention are: the present invention realizes the accuracy and real-time performance of weld tracking through the operation of the weld tracking system, and can more scientifically and accurately plan the use time of the robot during welding, automatically control the welding speed, thereby improving production efficiency and welding quality;

[0012] During welding, several spliced ​​plates are squeezed to reduce the weld seam and improve the welding quality. At the same time, the motor torque is controlled according to the number of plates. If there are many plates and weld seams, the motor torque is controlled to be reduced to ensure the reduction of the weld seam while avoiding excessive squeezing force on the plates, which may cause the plates in the middle to bulge and affect the welding quality. If there are few plates, the squeezing force on the plates is relatively increased to fully reduce the weld seam and make the welded plates stronger.

[0013] During the welding process, the push-pull plate is intermittently loose and tight, which on the one hand ensures the reduction of the weld seam, and on the other hand fully avoids the bulge of the middle plate, which can protect the welding quality of the plate to the greatest extent. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0015] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0016] Figure 2 It is a schematic diagram of the structural position above the base of the present invention;

[0017] Figure 3 It is a schematic diagram of the internal structure of the chamber of the present invention;

[0018] Figure 4 It is a schematic diagram of the gear installation position of the present invention;

[0019] Figure 5 It is a schematic diagram of the internal structure of the driving chamber of the present invention;

[0020] Figure 6 is a plan view of the driving cavity of the present invention;

[0021] Figure 7 It is a schematic diagram of the internal structure of the hollow cavity and the air pressure cavity of the present invention;

[0022] Figure 8 It is a schematic diagram of the connection relationship between the connecting shaft and the shaft rod of the present invention;

[0023] Fig. 9 It is a schematic diagram of the installation position of the card block of the present invention;

[0024] Fig.10 It is a schematic diagram of the module connection relationship of the weld tracking system of the present invention;

[0025] In the figure: 1. base; 2. Z axis; 21. laser welding head; 3. chamber; 31. slide plate; 32. push-pull rod; 33. push-pull plate; 4. drive chamber; 41. motor; 42. connecting shaft; 421. notch; 422. slot; 43. shaft; 431. boss; 432. block; 433. spring; 44. gear; 45. air pressure chamber; 451. air pressure plate; 452. tooth plate; 46. hollow cavity; 461. cylinder; 462. reciprocating rod; 463. strong magnet; 464. undulating plate; 465. limit rod; 466. elastic spring; 467. limit block; 47. telescopic joint; 471. pressure valve; 5. ring pipe; 6. air pipe. DETAILED DESCRIPTION

[0026] The following is a further non-limiting detailed description of the technical solution of the present invention in conjunction with the preferred embodiments and the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] See also Figure 1-10 The present invention provides a technical solution: a weld tracking system for tailor-welded plate welding, comprising a welding line and a weld tracking system, the welding line comprising a manipulator, a feeding mechanism, a six-axis welding part and a plate placement part, the six-axis welding part comprising a Z axis 2, a laser welding head 21 and a weld tracking sensor, the plate placement part comprising a base 1 and a fixing mechanism, the base 1 being placed on the welding line;

[0028] The fixing mechanism includes four fixing parts and a driving cavity 4. The four fixing parts each include a chamber 3, a slide plate 31, a push-pull rod 32 and a push-pull plate 33, and are evenly arranged around the top of the base 1. The weld tracking system includes a laser scanning visual sensor module, an image processing module and a feedback control module. The laser scanning visual sensor module is used to capture the real-time image of the weld through the weld tracking sensor, and calibrate it using the triangulation principle to obtain the shape and position information of the weld. The image processing module is used to identify the position and shape of the weld through image processing technology, edge detection and template matching algorithm, so as to calculate the height and Y-direction deviation to determine the specific position and shape deviation of the weld. The feedback control module is used to generate a control signal according to the identified weld position, and adjust the motion trajectory of the Z axis 2 in real time to maintain the accuracy of the weld.

[0029] The seam tracking sensor is used to calculate the movement path of the laser welding head through laser triangulation, where the laser triangulation method calculates the distance by measuring the change in angle of the laser pulse after it is reflected from the target object;

[0030] The tracking algorithm of laser triangulation is: Where D is the distance between the weld and the laser and receiver, i.e. the depth to be measured, F is the focal length of the receiving lens, L is the offset between the optical axis of the transmitting light path and the main optical axis of the receiving lens, i.e. the baseline distance, and d is the position offset above the receiving CCD detector;

[0031] This formula uses triangulation and known geometric relationships to calculate the distance of the weld. Specifically, when the laser beam is irradiated onto the weld and reflected back, its reflected light will be received by the CCD detector. Based on the position of the reflected light on the CCD detector, the offset of the laser beam can be calculated. Then, the position of the weld can be calculated using the above formula, and weld tracking can be performed.

[0032] The initial position and movement direction of the Z axis 2 are determined by moving the laser welding head 21 to the starting point, collecting data, and marking the middle point of the data as Calculated weld location points The direction of motion of the Z axis 2 is determined by the two-point method. The Z axis 2 moves to the next point, collects data, and recalculates the next weld feature point. according to Determine the next movement direction D0 of the weld tracking sensor and the origin of the weld tracking sensor coordinate system The origin δ is the scanning distance of the weld tracking sensor. The coordinate system of the current position of the weld tracking sensor and its origin position are obtained by calculation. The current position adjustment calculation of the weld tracking sensor includes position translation correction and position rotation correction. The middle point of the weld tracking sensor data is overlapped with the weld position point, and the weld tracking sensor is used to scan the data. From the C0 coordinate system calculate according to Determine T1 as the tangent direction of the weld and use it as the next movement direction; calculate Calculate the normal vector N1 and calculate the secondary tangent vector S1.

[0033] The Z axis 2 is installed on the welding line, and the laser welding head 21 and the weld tracking sensor are fixedly installed on the Z axis 2;

[0034] The chamber 3 is fixedly installed above the base 1, the slide plate 31 is slidably connected to the inner wall of the chamber 3, the push-pull plate 33 is fixedly connected to the slide plate 31 through the push-pull rod 32, the outer ends of the four chambers 3 are connected with an annular tube 5, the driving part is arranged inside the driving chamber 4, and the air pipe 6 is connected between the driving part and the annular tube 5;

[0035] The welding steps of the welding machine include:

[0036] Step S1, the manipulator grabs the plate and puts several plates between the push-pull plates 33 through the feeding mechanism, and splices them together. Then, the driving part generates air pressure, and the gas enters the ring tube 5 through the air pipe 6 and finally enters the chamber 3 to fix the plate and limit the plate;

[0037] Step S2, the Z axis 2 runs, driving the laser welding head 21 and the weld seam tracking sensor to move synchronously, the weld seam tracking sensor is aligned with the weld seam, and the real-time image of the weld seam is captured by the weld seam tracking sensor to obtain the shape and position information of the weld seam, and then determine the specific position and shape deviation of the weld seam, and finally adjust the motion trajectory of the Z axis 2 in real time according to the identified weld seam position, and weld the weld seam;

[0038] Step S3: During the welding process, the weld tracking speed is adjusted to track the welding in real time and complete the welding of several plates;

[0039] Through the operation of the weld tracking system, the accuracy and real-time performance of weld tracking are achieved.

[0040] In step S3, the welding seam tracking speed is adjusted as follows: Wherein, V is the weld tracking speed, L is the weld length, D is the wire diameter, R is the welding current, and Q is the welding coefficient, which is determined by the specific welding process and equipment, and is usually between 0.8 and 0.9;

[0041] When welding on the Z-axis 2, the robot's usage time can be planned more scientifically and accurately, and the welding speed can be automatically controlled, thereby improving production efficiency and welding quality.

[0042] The driving part includes a motor 41, a connecting shaft 42, a shaft 43, a gear 44 and a pneumatic chamber 45;

[0043] The motor 41 is fixedly mounted on the front side of the inner wall of the driving chamber 4, the connecting shaft 42 is fixedly connected to the output end of the motor 41, the gear 44 is connected to the bearing on the rear side of the inner wall of the driving chamber 4, and is connected to the connecting shaft 42 through the shaft 43, the inner wall of the air pressure chamber 45 is slidably connected with an air pressure plate 451, the left side of the air pressure plate 451 is fixedly mounted with a tooth plate 452, and the tooth plate 452 is meshed with the lower part of the gear 44, and the air pressure chamber 45 is connected to the air pipe 6;

[0044] The weld tracking system further includes a plate quantity recognition module and an intelligent control module. The quantity recognition module is arranged inside the weld tracking sensor and is electrically connected to the intelligent control module. The intelligent control module is electrically connected to the motor 41. The plate quantity recognition module is used to recognize the number of plates through the weld tracking sensor. The intelligent control module is used to control the torque of the motor 41 according to the number of plates.

[0045] The motor 41 runs, driving the shaft 43 to rotate through the connecting shaft 42, thereby driving the gear 44 to rotate, the gear 44 meshes with the tooth plate 452 to drive the tooth plate 452 to move to the right, the tooth plate 452 drives the air pressure plate 451 to slide to the right along the inner wall of the air pressure chamber 45, the gas on the right side of the air pressure plate 451 is squeezed into the air pipe 6 through the pipeline, then into the annular pipe 5, and finally into the chamber 3, the air pressure pushes the slide plate 31 to move, the slide plate 31 drives the push-pull plate 33 to move through the push-pull rod 32, thereby squeezing a number of spliced ​​plates, so that the weld is reduced and the welding quality is improved;

[0046] At the same time, the torque change of the motor 41 is controlled according to the number of plates. If there are a large number of plates and a large number of welds, the torque of the motor 41 is controlled to be reduced. While ensuring the reduction of the weld, it avoids excessive squeezing pressure on the plates, which causes the middle plate to bulge and affects the welding quality. If there are a small number of plates, the squeezing pressure on the plates is relatively increased, thereby fully reducing the weld and making the welded plates stronger.

[0047] A hollow cavity 46 is fixedly installed at the bottom of the inner wall of the driving cavity 4, a cylinder 461 is fixedly installed at the bottom of the inner wall of the hollow cavity 46, a reciprocating rod 462 is fixedly connected to the output end of the cylinder 461, and a strong magnet 463 is fixedly installed at the upper end of the reciprocating rod 462;

[0048] A slot 421 is provided at the rear end of the connecting shaft 42, and a plurality of slots 422 are provided in the inner circle of the slot 421. A boss 431 is provided at the front end of the shaft 43, and the boss 431 is inserted into the slot 421. A clamping block 432 is connected to one side of the boss 431, and a spring 433 is connected between the clamping block 432 and the outer surface of the boss 431. The clamping block 432 is clamped in the slot 422 and is located directly above the strong magnet 463. The clamping block 432 is magnetic, and its magnetic pole is the same as that of the strong magnet 463.

[0049] Through the above steps, during the welding process, the cylinder 461 runs, driving the reciprocating rod 462 to move up and down, thereby driving the strong magnet 463 to move up and down. When the strong magnet 463 moves upward, the strong magnet 463 generates a magnetic repulsion force. At this time, when the shaft 43 rotates to rotate the block 432 downward, the strong magnet 463 generates a magnetic repulsion force on the block 432, pushing the block 432 to rotate around the axis, thereby breaking away from the contact with the slot 422. At the same time, the spring 433 is deformed. At this time, since the slot 422 is out of contact with the block 432, the connecting shaft 42 can no longer drive the shaft The rod 43 rotates, so that the gear 44 stops rotating, and the push-pull plate 33 keeps squeezing the plate with a relatively stable squeezing force. However, due to welding, the plates become loose. At this time, the reciprocating rod 462 moves downward to reset, and the strong magnet 463 moves away from the block 432. The spring 433 generates a reaction force to make the block 432 re-engage with the slot 422. This process makes the push-pull plate 33 intermittently loosen and tighten the plate, thereby ensuring the reduction of the weld on the one hand, and fully avoiding the bulge of the middle plate on the other hand, which can protect the plate welding quality to the greatest extent.

[0050] An undulating plate 464 is fixedly mounted on the outer side of the reciprocating rod 462, and the undulating plate 464 is slidably connected to the inner wall of the hollow cavity 46, and the upper side of the hollow cavity 46 is connected to the right side pipeline of the air pressure cavity 45;

[0051] Through the above steps, when the connecting shaft 42 cannot drive the shaft rod 43 to rotate, the reciprocating rod 462 moves upward, driving the undulating plate 464 to move upward, and the gas above the undulating plate 464 is squeezed and enters the left side of the air pressure plate 451 through the pipe, and the gas then enters the chamber 3 through the pipe, so that the push-pull plate 33 moves further inward, avoiding continuous loosening between the plates during welding, resulting in an increase in the weld, and relatively improving the clamping force on the plates. At the same time, because the shaft rod 43 is disconnected from the connecting shaft 42 at this moment, the air pressure plate 451 is affected by the air pressure in the hollow cavity 46 and moves to the left, which can both relatively improve the clamping force on the plates and avoid excessive clamping force, thereby fully protecting the welding quality of the plates.

[0052] A sliding hole is provided above the hollow cavity 46, and the inner wall of the slide block is slidably connected to a limit rod 465, a limit block 467 is fixed to the outer side of the limit rod 465, and an elastic spring 466 is provided between the limit block 467 and the outer wall above the hollow cavity 46;

[0053] A telescopic joint 47 is fixedly installed below the left end of the tooth plate 452, and the telescopic joint 47 is connected to the left hose of the air pressure chamber 45, and a pressure valve 471 is arranged in the hose. The left side of the air pressure chamber 45 is connected to an external pipeline, and a one-way valve is arranged in the pipeline. The left side of the telescopic joint 47 is connected to an external control valve hose. The upper end of the limit rod 465 and the lower end of the telescopic joint 47 are both spherical and aligned with each other.

[0054] The gear 44 rotates intermittently, so that the air pressure plate 451 continuously moves back and forth in a small range. The left side of the air pressure plate 451 draws gas from the outside through a pipeline and injects it into the hose until the air pressure in the hose reaches the pressure bearing limit of the pressure valve 471. The pressure valve 471 opens, and the gas enters the telescopic joint 47 to stretch it. When the tooth plate 452 moves left and right, the telescopic joint 47 is driven to move left and right. The lower end of the telescopic joint 47 contacts and squeezes the upper end of the limit rod 465. The limit rod 465 is stressed, and the elastic spring 466 is deformed. The limit rod 465 moves downward, so that the undulating plate 464 is limited. At this time, the plate is about to complete the welding work, thereby reducing the squeezing force on the plate. After the welding is completed, the operator can directly remove the plate without waiting for the push-pull plate 33 to reset, saving working time.

[0055] In the description of the present invention, it is necessary to understand that the terms "up", "down", "front", "back", "left", "right", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0056] Finally, it should be pointed out that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them. Although the present invention has been described in detail with reference to the above embodiments, a person skilled in the art should understand that the technical solutions described in the above embodiments can still be modified, or some of the technical features can be replaced by equivalents, and these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A weld tracking system for tailor-welded blanks, comprising a welding line and a weld tracking system, characterized in that: The welding line comprises a manipulator, a feeding mechanism, a six-axis welding part and a plate placement part, the six-axis welding part comprises a Z axis (2), a laser welding head (21) and a weld seam tracking sensor, the plate placement part comprises a base (1) and a fixing mechanism, and the base (1) is placed on the welding line; The fixing mechanism comprises four fixing parts and a driving cavity (4), the four fixing parts each comprising a chamber (3), a slide plate (31), a push-pull rod (32) and a push-pull plate (33), and are evenly arranged around the top of the base (1); the weld tracking system comprises a laser scanning visual sensing module, an image processing module and a feedback control module; the laser scanning visual sensing module is used to capture a real-time image of the weld through a weld tracking sensor, and calibrate using the triangulation principle to obtain the shape and position information of the weld; the image processing module is used to identify the position and shape of the weld through image processing technology, edge detection and template matching algorithm, thereby calculating the height and Y-direction deviation to determine the specific position and shape deviation of the weld; the feedback control module is used to generate a control signal according to the identified weld position, and to monitor the motion trajectory of the laser welding head (21) in real time to maintain the accuracy of the weld; The weld tracking sensor is used to calculate the movement path of the laser welding head by laser triangulation, wherein the laser triangulation calculates the distance by measuring the angle change of the laser pulse after it is reflected on the target object; The tracking algorithm of the laser triangulation method is: Where D is the distance between the weld and the laser and receiver, i.e. the depth to be measured, F is the focal length of the receiving lens, L is the offset between the optical axis of the transmitting light path and the main optical axis of the receiving lens, i.e. the baseline distance, and d is the position offset above the receiving CCD detector.

2. A weld tracking system for tailor-welded blanks according to claim 1, characterized in that: The Z axis (2) is installed on the welding line, and the laser welding head (21) and the weld seam tracking sensor are both fixedly installed on the Z axis (2); The chamber (3) is fixedly installed above the base (1); the slide plate (31) is slidably connected to the inner wall of the chamber (3); the push-pull plate (33) is fixedly connected to the slide plate (31) via a push-pull rod (32); an annular tube (5) is connected between the outer ends of the four chambers (3); a driving part is provided inside the driving chamber (4); and an air pipe (6) is connected between the driving part and the annular tube (5); The welding steps of the welding machine include: Step S1, the robot grabs the plate and puts several plates between the push-pull plates (33) through the feeding mechanism, and splices them together. Then, the driving part generates air pressure, and the gas enters the ring tube (5) through the air pipe (6) and finally enters the chamber (3) to fix the plate and limit the plate. Step S2, the Z axis (2) runs, driving the laser welding head (21) and the weld seam tracking sensor to move synchronously, the weld seam tracking sensor is aligned with the weld seam, and a real-time image of the weld seam is captured by the weld seam tracking sensor to obtain the shape and position information of the weld seam, and then determine the specific position and shape deviation of the weld seam, and finally weld the weld seam according to the identified weld seam position and the movement trajectory of the real-time laser welding head (21); Step S3: During the welding process, the weld tracking speed is adjusted to track the welding in real time and complete the welding of several plates.

3. A weld tracking system for tailor-welded blanks according to claim 2, characterized in that: In step S3, the welding seam tracking speed is adjusted as follows: Among them, V is the weld tracking speed, L is the weld length, D is the wire diameter, R is the welding current, and Q is the welding coefficient, which depends on the specific welding process and equipment and is usually between 0.8 and 0.

9.

4. A weld tracking system for tailor-welded blanks according to claim 3, characterized in that: The driving part comprises a motor (41), a connecting shaft (42), a shaft (43), a gear (44) and an air pressure chamber (45); The motor (41) is fixedly mounted on the front side of the inner wall of the driving chamber (4); the connecting shaft (42) is fixedly connected to the output end of the motor (41); the gear (44) is connected to the bearing on the rear side of the inner wall of the driving chamber (4) and is connected to the connecting shaft (42) via a shaft (43); the inner wall of the air pressure chamber (45) is slidably connected to a pneumatic plate (451); a tooth plate (452) is fixedly mounted on the left side of the pneumatic plate (451), and the tooth plate (452) and the lower part of the gear (44) are meshed with each other; the air pressure chamber (45) is connected to the air pipe (6); The weld tracking system further comprises a plate quantity identification module and an intelligent control module, wherein the quantity identification module is arranged inside the weld tracking sensor and is electrically connected to the intelligent control module, and the intelligent control module is electrically connected to the motor (41), the plate quantity identification module is used to identify the number of plates through the weld tracking sensor, and the intelligent control module is used to control the torque of the motor (41) according to the number of plates.

5. A weld tracking system for tailor-welded blanks according to claim 4, characterized in that: A hollow cavity (46) is fixedly mounted on the bottom of the inner wall of the driving cavity (4), a cylinder (461) is fixedly mounted on the bottom of the inner wall of the hollow cavity (46), a reciprocating rod (462) is fixedly connected to the output end of the cylinder (461), and a strong magnet (463) is fixedly mounted on the upper end of the reciprocating rod (462); The rear end of the connecting shaft (42) is provided with a slot (421), the inner ring of the slot (421) is provided with a plurality of slots (422), the front end of the shaft rod (43) is provided with a boss (431), and the boss (431) is inserted into the slot (421), a side axis of the boss (431) is connected with a block (432), a spring (433) is connected between the block (432) and the outer surface of the boss (431), the block (432) is engaged in the slot (422), and is located directly above the strong magnet (463), the block (432) is magnetic, and the magnetic pole is the same as that of the strong magnet (463).

6. A weld tracking system for tailor-welded blanks according to claim 5, characterized in that: An undulating plate (464) is fixedly mounted on the outer side of the reciprocating rod (462), and the undulating plate (464) is slidably connected to the inner wall of the hollow cavity (46), and the upper side of the hollow cavity (46) is connected to the right side pipeline of the air pressure cavity (45).

7. A weld tracking system for tailor-welded blanks according to claim 6, characterized in that: A sliding hole is provided above the hollow cavity (46), and the inner wall of the sliding block is slidably connected to a limit rod (465), a limit block (467) is fixed on the outer side of the limit rod (465), and an elastic spring (466) is provided between the limit block (467) and the outer wall above the hollow cavity (46); A telescopic joint (47) is fixedly installed below the left end of the tooth plate (452), the telescopic joint (47) is connected to the left hose of the air pressure chamber (45), and a pressure valve (471) is arranged in the hose, the left side of the air pressure chamber (45) is connected to an external pipeline, and a one-way valve is arranged in the pipeline, the left side of the telescopic joint (47) is connected to the external control valve hose, and the upper end of the limit rod (465) and the lower end of the telescopic joint (47) are both spherical and aligned with each other.

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