Welding gun action control method and related equipment

Abstract

The invention discloses a welding gun action control method and related equipment, and the method comprises the steps: determining a target welding gun motion state corresponding to each scanning time point in a process that a welding gun moves from a starting point position to a final point position by calling a preset welder action simulation algorithm, the preset welder action imitation algorithm is an algorithm for converting the welder welding action into weighted summation of a plurality of Gaussian primitive functions. And generating a corresponding welding gun control instruction according to the target motion path information obtained by summarizing the target welding gun motion state corresponding to each scanning time point, and sending the corresponding welding gun control instruction to the controller. According to the method, the welding action of the welder is converted into data in a data form for controlling the movement of the welding gun, so that the welding gun can reproduce the welding action of the welder, the welding requirements of operators are met, the method adapts to the groove welding state, and the flexibility is higher.

Description

Technical Field

[0001] The present application relates to the technical field of intelligent arc welding, and more specifically, to a welding gun motion control method and related equipment. Background Art

[0002] Welding is an important metal connection technology. During the welding process, it is necessary to adopt flexible and complex welding paths with swinging, such as crescent-shaped, oblique circle-shaped, triangular, and zigzag paths, according to the geometric shape of the workpiece and the thermal deformation during welding, in order to obtain high-quality welds. High-quality welds have shown significant benefits in improving overall structural strength, enhancing sealing and corrosion resistance, and improving aesthetics and process quality.

[0003] Currently, robots are used to automate welding and improve efficiency. Robotic welding primarily relies on taught-in programming or offline programming to create a path. However, these programmed paths are rigid and simple, making them unsuitable for welding complex workpieces, resulting in reduced weld quality. Summary of the Invention

[0004] In view of the above problems, this application provides a welding gun motion control method and related equipment to achieve the purpose of automatically controlling the welding gun for flexible and precise welding. The specific solution is as follows:

[0005] A first aspect of the present application provides a welding gun motion control method, which is applied to a processor of a welding gun motion control system, wherein the welding gun motion control system at least includes: a welding gun and a controller for controlling the welding gun, including:

[0006] Acquiring geometric feature information of the groove to be welded, the geometric feature information at least including: scanning the groove to be welded at a preset scanning speed, and obtaining the starting position and the ending position of the groove to be welded;

[0007] calling a preset welder motion simulation algorithm to determine a target welding gun motion state corresponding to each scanning time point during the movement of the welding gun from the starting position to the end position, wherein the preset welder motion simulation algorithm is an algorithm for converting the welder's welding motion into a weighted sum of multiple Gaussian basis functions, wherein the welder's welding motion is the welding gun motion of the welder during the process of welding a workpiece sample having a groove type consistent with the groove to be welded, and the Gaussian basis function is a state function simulating the welding gun motion;

[0008] Summarizing the target welding gun motion state corresponding to each scanning time point to generate target motion path information of the welding gun moving from the starting position to the end position;

[0009] A welding gun control instruction including the target motion path information is generated, and the welding gun control instruction is sent to the controller.

[0010] In a possible implementation, calling a preset welder motion simulation algorithm to determine the target welding gun motion state corresponding to each scanning time point during the process of the welding gun moving from the starting position to the end position includes:

[0011] Acquiring reference motion path information, the reference motion path information being a motion path of the welding gun under the welder's operation, collected in advance from a process in which the welder welds a workpiece sample, the workpiece sample being a groove of the same type as the groove to be welded, the reference motion path information including: a welding gun position and a relative posture of the welding gun corresponding to each welding time point of the workpiece sample, the welding time point being a time point when the workpiece sample is welded at a welding speed consistent with the scanning speed;

[0012] Based on the reference motion path information, data fitting is performed on the welding gun position and the relative posture of the welding gun to construct a dynamic system corresponding to the motion degrees of freedom, wherein the dynamic system includes a plurality of predefined Gaussian basis functions and their weight coefficients, and the Gaussian basis functions and their weight coefficients continuously act during the motion process;

[0013] Using each of the Gaussian basis functions and their weight coefficients, a weighted sum is performed on a plurality of the Gaussian basis functions to obtain a welding gun motion state between the starting position and the end position, including a target welding gun motion state corresponding to each of the scanning time points.

[0014] In a possible implementation, obtaining reference motion path information includes:

[0015] Acquiring workpiece information of the workpiece sample and motion path information of the welding gun captured by a motion capture device during a process in which a welder operates a welding gun to weld the workpiece sample, wherein the motion path information includes: the welding gun position and the welding gun initial posture at each welding time point, and the workpiece information includes: the workpiece position and the workpiece posture;

[0016] Based on the workpiece posture and the welding gun initial posture, a welding gun relative posture corresponding to the welding gun initial posture is determined, where the welding gun relative posture is a motion posture of the welding gun relative to the workpiece sample.

[0017] In a possible implementation, calling a preset welder motion simulation algorithm to determine the target welding gun motion state corresponding to each scanning time point during the process of the welding gun moving from the starting position to the end position includes:

[0018] Calling a preset welder motion simulation algorithm, based on the groove type, starting position, and end position of the groove to be welded, determining the welding gun position and welding gun relative posture corresponding to each scanning time point during the movement of the welding gun from the starting position to the end position, and counting them as the initial welding gun motion state;

[0019] According to the width and depth of the scanned position at each scanning time point in the geometric feature information, the initial welding gun motion state is adjusted respectively to obtain the target welding gun motion state corresponding to each scanning time point.

[0020] In a possible implementation, adjusting the initial welding gun motion state according to the width and depth of the scanned position at the scanning time point to obtain the target welding gun motion state corresponding to each scanning time point includes:

[0021] Determining a time scaling factor corresponding to the scanning time point based on the width at the scanning time point, the time scaling factor representing a scaling degree of the swing amplitude of the welding gun at the width;

[0022] Determining, based on the depth at the scanning time point, a scale scaling factor corresponding to the scanning time point, wherein the scale scaling factor represents a scaling degree of a moving speed of the welding gun at the depth;

[0023] According to the time scaling factor and the scale scaling factor corresponding to the scanning time point, the welding gun swing amplitude and the welding gun movement speed of the initial welding gun motion state are corrected to obtain the target welding gun motion state corresponding to the scanning time point.

[0024] In a possible implementation, generating a welding gun control instruction including the target motion path information includes:

[0025] identifying a welding gun type of the welding gun;

[0026] Acquire a mechanical structure corresponding to the welding gun type, where the mechanical structure is a structure for manipulating the movement of the welding gun;

[0027] According to an inverse kinematics solution algorithm, the target motion path information is converted into a control instruction suitable for the mechanical structure.

[0028] In a possible implementation, the target welding gun motion state includes at least: welding gun position, welding gun posture, welding gun moving speed, and welding gun swing amplitude.

[0029] A second aspect of the present application provides a computer program product, comprising computer-readable instructions. When the computer-readable instructions are executed on an electronic device, the electronic device implements the welding gun motion control method of the first aspect or any implementation of the first aspect.

[0030] A third aspect of the present application provides a welding gun motion control system, comprising: a welding gun, a processor, and a controller for controlling the welding gun;

[0031] The processor is used to implement the welding gun motion control method of the first aspect or any implementation of the first aspect;

[0032] The controller is used to receive the welding gun control instruction sent by the processor and control the operation of the welding gun according to the welding gun control instruction.

[0033] In a fourth aspect, the present application provides a computer storage medium carrying one or more computer programs. When the one or more computer programs are executed by a processor of a welding gun motion control system, the welding gun motion control system can implement the welding gun motion control method of the first aspect or any implementation of the first aspect.

[0034] As can be seen from the above technical solutions, the welding gun motion control method provided in the embodiments of the present application uses a preset welder motion simulation algorithm to digitize the welding gun motion of a welder of the same groove type as the groove to be welded. The result of the weighted summation of multiple Gaussian basis functions is used as the welding gun motion state. Based on this, the initial welding gun motion state corresponding to each scanning time point during the process of the welding gun simulating the welder's movement from the starting position to the end position of the groove to be welded is determined.

[0035] Compared with the existing technology that controls the movement of the welding gun based on solidified code, this application converts the welder's welding action into data form to control the movement of the welding gun, and controls the welding gun based on the data in this data form, so that the welding gun can reproduce the welder's welding action, better meet the operator's welding needs, and achieve better welding results. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without any creative work.

[0037] Figure 1 A flow chart of a method for controlling the movement of a welding gun according to an embodiment of the present application;

[0038] Figure 2 An example diagram of a workpiece sample provided in an embodiment of the present application;

[0039] Figure 3 A schematic structural diagram of a six-degree-of-freedom swinging integrated welding gun device provided in an embodiment of the present application;

[0040] Figure 4 Schematic diagram of the coordinate system of the six-degree-of-freedom swinging integrated welding device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0041] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0042] The welding effect of welding guns operated by programming is not as good as that of manual welding. This is because the welding action of the welding gun under programming operation is fixed. However, excellent welders observe the shape of the groove during the welding process, constantly adjust the position and posture of the welding gun, and flexibly change the gun movement technique to obtain high-quality welds. Based on this, the embodiments of the present application provide a welding gun motion control method to solve the problem of inflexible and precise control of the welding gun during automated welding, which leads to poor welding results.

[0043] The welding gun motion control method is applied to a processor of a welding gun motion control system, which includes at least a welding gun and a controller for controlling the welding gun. Alternatively, the welding gun motion control system may be automated welding equipment, a welding robot, or the like, wherein the functional element for storing or processing welding gun motion data may employ the welding gun motion control method.

[0044] Specifically, refer to Figure 1 The embodiment of the present application provides a flow chart of a method for controlling the motion of a welding gun, which describes in detail the method for controlling the motion of a welding gun applied to a processor. The flow of the method may include the following steps:

[0045] Step S110, obtaining geometric feature information of the groove to be welded.

[0046] The geometric feature information includes at least: the starting position and the end position of the groove to be welded obtained by scanning the groove to be welded at a preset scanning speed, and the width and depth of the scanned position at each scanning time point during the process of scanning from the starting position to the end position.

[0047] Optionally, a sensor or camera mounted on a welding gun, robot, or robotic arm is used to scan the groove to be welded and obtain geometric feature information of the groove. In one possible implementation, the robotic arm is controlled so that a laser line scan sensor, carried at the end of the robotic arm, scans above the groove to be welded. The image captured by the CCD camera, including the laser line projected on the groove to be welded, is processed to accurately identify and extract the centerline and intersection of the laser line in the image, as well as feature point information such as the bend point generated at the edge of the groove. The geometric feature information of the groove to be welded, such as the starting and ending positions of the weld, and the width and depth of each part of the groove, is obtained through a related algorithm.

[0048] In the embodiment of the present application, the groove to be welded is scanned at a preset scanning speed. Therefore, each scanning time point corresponds to a welding point on the groove to be welded. The groove width, depth, and position corresponding to the scanning time point are all the width, depth, and position of the welding point. Based on this, the embodiment of the present application can locate each welding point on the groove to be welded at the scanning time point. In addition, the preset scanning speed can refer to the welding speed during manual welding and the welding speed during the groove to be welded. The welding point corresponding to each scanning time point is exactly the same as the welding point corresponding to each welding time point during the manual welding process, which facilitates point-to-point matching between the welder's welding process and the current welding process.

[0049] Step S120 , calling a preset welder motion simulation algorithm to determine a target welding gun motion state corresponding to each scanning time point in the process of the welding gun moving from the starting position to the end position.

[0050] Among them, the target welding gun motion state includes at least: welding gun position, welding gun posture, welding gun moving speed and welding gun swing amplitude; the preset welder action imitation algorithm is an algorithm that converts the welder's welding action into a weighted sum of multiple Gaussian basis function, the welder's welding action is the welding gun action during the welder welding a workpiece sample with the same groove type as the groove to be welded, and the Gaussian basis function is a state function that simulates the welding gun action.

[0051] The preset welder motion simulation algorithm in the embodiments of the present application can be understood as pre-collecting the welding gun motion of a welder operating a welding gun while welding a sample workpiece with the same groove type as the groove to be welded, and using this as the basis for generating the simulated welder's welding motion. The welding gun motion corresponding to each weld point can be considered as a complete motion composed of multiple different motion elements. For example, a continuous welding trajectory can be decomposed into a superposition of multiple Gaussian motion primitives (Gaussian basis functions), each representing a local motion mode, and the weight coefficient quantifying the contribution of each mode to the overall motion. This structure can not only accurately reproduce the taught trajectory but also adapt to different groove geometries in real time by adjusting target parameters. It is essentially a motion generation framework based on a dynamic system, combining biomimetic properties with mathematical interpretability.

[0052] Based on this, the present embodiment converts the welder's welding motion at each moment into a state function that is a weighted sum of multiple Gaussian basis functions. The Gaussian basis functions simulate the state of the welding gun and correspond to the motion elements in a complete motion. By weighting each Gaussian basis function, the contribution of each motion element in the welding motion is distinguished. Furthermore, the weighted sum of each Gaussian basis function yields the digitized welder's welding motion.

[0053] According to the above algorithm, the digitized welding actions of the welder of the same type of welding groove are transferred to the welding groove to be welded, and the welding gun state corresponding to each scanning time point in the process of the welding gun moving from the starting position to the end position of the welding groove to be welded is obtained.

[0054] In a possible implementation process, the process of executing step S120 may include: obtaining reference motion path information, the reference motion path information is the motion path of the welding gun under the operation of the welder, which is collected in advance from the process of the welder welding the workpiece sample, the workpiece sample is a groove consistent with the groove type of the groove to be welded, and the reference motion path information includes: the welding gun position and the relative posture of the welding gun corresponding to each welding time point of the workpiece sample, and the welding time point is the time point when the workpiece sample is welded at a welding speed consistent with the scanning speed; based on the reference motion path information, data fitting is performed on the welding gun position and the relative posture of the welding gun to construct a dynamic system corresponding to the degree of freedom of motion, the dynamic system includes multiple predefined Gaussian basis functions and their weight coefficients, and the Gaussian basis functions and their weight coefficients continue to act during the motion process; using each Gaussian basis function and its weight coefficient, a weighted summation is performed on the multiple Gaussian basis functions to obtain the welding gun motion state between the starting point and the end point, including the target welding gun motion state corresponding to each scanning time point.

[0055] A pre-stored reference motion path of the same groove type as the one to be welded is obtained locally. The reference motion path is pre-collected data on the welding motion process when the welder welds a workpiece sample of this groove type. This reference motion path can include: a position path, which includes the welding gun position at each welding point / time point in the entire welding process; and a posture path, which includes the welding gun posture at each welding point / time point in the entire welding process. This path is used as the basis for simulating the welder's welding movements and generating welding gun motion data corresponding to the groove to be welded.

[0056] Optionally, the embodiment of the present application takes the groove type of base welding or single-sided welding and double-sided forming of tubular and plate-shaped workpieces with large wall thickness and wide gap as an example of the groove type to be welded, and captures the welder's welding process through a motion capture device of the welder's manual arc welding process to obtain reference motion path information.

[0057] In one possible implementation, the motion capture device may include 6-10 motion capture cameras, a workpiece sample, and a manual welding system. The workpiece sample includes a groove of the aforementioned type. The manual welding system includes a manual welding gun, a welding machine, and a shielding gas cylinder. The manual welding gun and the workpiece sample are each affixed with at least three reflective marker targets for positioning. The motion capture camera captures each reflective marker target to record the groove pattern of the workpiece sample and the welder's movement path while using the manual welding gun on the workpiece sample.

[0058] Specifically, refer to Figure 2 , an example diagram of a workpiece sample provided in an embodiment of the present application, wherein each workpiece sample is affixed with at least three reflective marking target balls, target ball 1 and target ball 2 are placed on one side of the groove, and target ball 3 is placed on the other side of the groove, the line connecting target balls 1 and 2 is parallel to the groove weld, the line connecting target balls 1 and target balls 3 is perpendicular to the weld, and target balls 1 and target balls 3 are symmetrical about the weld axis, and the line connecting target balls 1 and 2 is perpendicular to the line connecting target balls 1 and 3. Based on this, a workpiece coordinate system can be established according to the position of the target balls, as follows: target ball 1 is used as the origin of the workpiece coordinate system, the line connecting target balls 1 and target balls 2 is used as the X-axis of the workpiece coordinate system, and the line connecting target balls 1 and target balls 3 is used as the Y-axis. At the same time, a groove weld coordinate system can also be established based on the workpiece coordinate system, but the origin positions of the two coordinate systems are different, such as Figure 2 As shown, the origin of the groove weld coordinate system is the midpoint of the weld located on the straight line between the target spheres 1 and 3. Based on this, the position of the groove weld coordinate system can be calculated according to the distance between the target spheres 1 and 3 and the position of the workpiece coordinate system.

[0059] As a welder operates a manual welding torch on a workpiece sample, the LED array on the motion capture camera emits 800nm infrared light, which is reflected by a target ball and captured by a backup camera. The motion capture device then performs detection, image processing, and data analysis, transmitting the three-dimensional coordinates of each target ball in a coordinate system (such as the workpiece coordinate system, weld coordinate system, and world coordinate system) to a computer or processor. The computer uses the three-dimensional coordinates of at least three target balls to calculate the six-dimensional pose of the workpiece sample and welding torch, namely the X, Y, and Z coordinates and three Euler angles (pose).

[0060] Furthermore, based on the six-dimensional posture of the workpiece sample and the welding gun, the reference motion path information of the welding gun is determined, which can specifically include: obtaining the workpiece information of the workpiece sample and the motion path information of the welding gun captured by the motion capture device during the process of the welder operating the welding gun to weld the workpiece sample, the motion path information including: the welding gun position and the initial posture of the welding gun at each welding time point, and the workpiece information including: the workpiece position and the workpiece posture; based on the workpiece posture and the initial posture of the welding gun, determining the relative posture of the welding gun corresponding to the initial posture of the welding gun, the relative posture of the welding gun being the motion posture of the welding gun relative to the workpiece sample.

[0061] In an embodiment of the present application, the dynamic three-dimensional coordinates of the reflective marker target ball captured by the motion capture device are first obtained. Based on this, the initial posture Twg(t) of the welding gun and the workpiece posture Twp(t) during the welding process of the welder are restored, where t represents the welding time point. Based on the workpiece coordinate system and the welding gun coordinate system established above, the relative posture wgTWP(t) of the welding gun coordinate system relative to the workpiece coordinate system is calculated. Based on this relative posture, the welding gun posture Twg(t) is converted to obtain the relative posture of the welding gun as the component information of the welding gun posture path. According to the above posture calculation method, the XYZ coordinates of the position point of the welding gun can also be converted into relative coordinates as the component information of the welding gun position path. Based on the welding gun posture path and the welding gun position path, the reference motion path information of the welding gun in the sample representing the welder's welding of the workpiece is determined.

[0062] Furthermore, using the dynamic motion primitive method, the reference motion path of the welding gun is treated as a superposition of dynamic motion elements with different weights. Through data training and fitting, the Gaussian basis functions representing each dynamic motion element in the motion path are calculated, along with the weights assigned to each Gaussian basis function. Based on these weights, the weighted summation of the Gaussian basis functions is used to represent the corresponding welding gun motion state. The welding gun motion states corresponding to all welding time points are connected together according to the time sequence, forming the digitized motion path information that simulates the welding action of the welder.

[0063] Specifically, the process of converting the coordinates and postures in the reference motion path information into the welding gun motion state in the form of a function can be referred to the following description. First, the dynamic motion primitive method is used to perform data fitting on the reference motion path information (position path and posture path) of manual welding. A second-order dynamic system is used to fit the reference motion path information. The fitting result is as follows (1):

[0064] (1)

[0065] Among them, y is the motion state of the welding gun, which can represent any coordinate among X, Y, and Z, or any of the three Euler angles of the welding gun posture; 、 are the first-order and second-order derivatives of the motion state; g is the end point position of the welding gun motion path; α and β are proportional factors, which are parameters set before training.

[0066] Since the welding motion state y can represent the xyz coordinate state and posture state, and the posture, coordinate position, etc., can determine the position, moving speed (welding speed), moving angle, swing amplitude and other information of the welding gun in the current state.

[0067] The welding gun motion state generated according to formula (1) will converge to the end position g of the motion path. According to the time sequence of the generated motion state y corresponding to the time t, all motion states y are integrated to obtain a complete motion path.

[0068] Since the motion state generated by Equation (1) only considers the consistency of the starting point and the end point and cannot control the shape of the path, based on this, an external driving force f(x) is added after Equation (1), and the resulting welding gun motion state is as follows Equation (2). Based on this, in addition to controlling the starting point and end point of the generated path, the shape of the generated path can also be controlled to approach the welding gun path during the welding process.

[0069] (2)

[0070] Among them, f(x) represents the shape learner, which consists of several different weights Gaussian basis function The superposition is as follows (3):

[0071] (3)

[0072] Where N is the total number of Gaussian basis functions, and i represents the i-th Gaussian basis function. x is a normalized state variable, and its differential with respect to time t is 1, indicating that x is a variable that increases linearly with time, or a function of time t. x is a function of t, and is a function of x, that is, It can be understood as a function of t, then Represents the Gaussian basis function corresponding to the scanning time point or welding time point t, and then, The weighted summation is performed to obtain f(x), which controls the shape of the generated path. This makes the path of the second-order dynamic welding gun motion state y under the influence of the external driving force f(x) approach the shape of the welding gun motion path during the welding process.

[0073] Since the workpiece sample is consistent with the groove type of the groove to be welded, it is understandable that the movement of the welding gun will hardly be much different when welding the same type of groove. Therefore, based on the digitized motion path information, such as modifying the starting and ending positions of the groove, welding time, etc., the target welding gun motion state corresponding to each scanning time point (also regarded as a welding point) from the starting position to the end position of the groove to be welded can be adaptively generated.

[0074] In step S130 , target motion path information of the welding gun moving from the starting position to the ending position is generated according to the target welding gun motion state corresponding to each scanning time point.

[0075] Step S140: Generate a welding gun control instruction including target motion path information, and send the welding gun control instruction to the controller.

[0076] The target welding gun motion state corresponding to each scanning time point obtained in step S120 is summarized and the target welding gun motion states corresponding to each adjacent scanning time point are spliced together to obtain relatively smooth and natural welding gun motion during these adjacent scanning time points. Based on this, target motion path information for the welding gun moving from the starting position to the end position is generated.

[0077] It is understandable that the target motion path is still in the form of a function, and the controller of an automatic welding gun device, robot, or other device cannot parse the motion instructions to control the welding gun. Therefore, in the embodiment of the present application, the target motion path is converted into welding gun control instructions suitable for the device, and the welding gun control instructions are sent to the controller, so that the controller can directly control the welding gun.

[0078] Considering that different automation equipment or welding gun structures require different types of instructions, one possible implementation converts the target motion path into different instruction formats for different welding gun devices. Specifically, this includes: identifying the welding gun type; obtaining the mechanical structure corresponding to the welding gun type, which is used to control the movement of the welding gun; and converting the target motion path information into control instructions suitable for the mechanical structure based on an inverse kinematics solution algorithm.

[0079] The target motion path and posture path are used as inputs, and the inverse kinematics solution algorithm is called to solve the instruction data adapted to the mechanical structure of the welding gun. First, the type of welding gun needs to be identified. The embodiment of this application uses the identified six-degree-of-freedom swinging integrated welding gun device as an example for explanation. Figure 3, an embodiment of the present application provides a structural schematic diagram of a six-degree-of-freedom swinging integrated welding gun device, which includes: a welding gun head 1, a six-degree-of-freedom platform 2, a welding gun body 3, a transition device 4, an anti-collision mechanism 5, a transition mechanism 6, and an adapter plate 7. The six-degree-of-freedom platform includes a top plate 201, a bottom plate 202, six groups of connecting rods 203, a universal joint, a linear servo motor with a driver, etc. The six-degree-of-freedom swinging integrated welding gun device can achieve flexible swinging of the top plate and the welding gun head through the extension and retraction of the six connecting rods.

[0080] Among them, the six groups of connecting rods are mechanical structures used to control the movement of the welding gun. In the inverse kinematics solution algorithm, the motion structure of the six-degree-of-freedom swinging integrated welding gun device can be used to reversely infer step by step from the welding gun posture, and finally obtain the telescopic length of the six connecting rods.

[0081] Specifically, the six-degree-of-freedom swinging integrated welding gun device is composed of a welding gun head, a lower end ring, six connecting rods, an upper end ring, and the end of a robotic arm from bottom to top. The swinging integrated welding gun device is composed of a welding gun head, a lower end ring, six connecting rods, an upper end ring, and the end of a robotic arm from bottom to top. Due to the redundant degrees of freedom of the device, there are countless sets of inverse kinematic solutions. In order to obtain a single inverse solution, the inverse kinematics solution algorithm is first restricted. Figure 4 , as follows: Condition 1, the welding gun head is on the Z axis (central axis) of the lower end ring coordinate system and is perpendicular to the XY plane of the lower end ring. When performing path planning, the lower end ring can rotate around the central axis of the welding gun without affecting the welding effect; Condition 2, the position of the upper end ring changes with the movement of the robot end, but the posture remains unchanged; Condition 3, the origin of the lower end ring coordinate system is always on the Z axis (central axis) of the upper end ring coordinate system.

[0082] Furthermore, in the target motion path information, the position T of the welding gun coordinate system at the scanning time point t is obtained. 焊枪 , as shown in formula (4):

[0083] (4)

[0084] Among them, R 焊枪 V is a rotation matrix that represents the posture of the welding gun and describes the pitch angle (Pitch), yaw angle (Yaw) and roll angle (Roll) of the welding gun; 焊枪 is the translation vector, which represents the position coordinate (x, y, z) of the origin of the welding gun coordinate system in the global coordinate system.

[0085] A coordinate system is established for the lower end ring so that the lower end ring coordinate system completely coincides with the welding gun coordinate system. However, due to condition 1, the welding gun rotates around its own central axis and does not affect the welding process. Only the pitch angle and yaw angle of the welding gun affect the welding process. Therefore, the lower end ring coordinate system can be rotated around the Z axis by an angle θ to obtain the lower end ring posture T.下 , as shown in formula (5):

[0086] (5)

[0087] In order to reduce the redundancy problem in the inverse solution process, the following settings can be made: the upper ring always maintains the same posture; the origin of the lower ring coordinate system is forced to be on the Z axis of the upper ring coordinate system, but the distance L between the origin of the lower ring coordinate system and the origin of the upper ring coordinate system is set to be adjustable, that is, their relationship can be referred to the following formula (6):

[0088] (6)

[0089] Set the coordinates of the six nodes of the upper ring (centers of the universal joint) in the upper ring coordinate system to: , i=1,……,6, the coordinates of the 6 nodes of the lower ring in the lower ring coordinate system are: , i=1,……,6. Based on this, the coordinates Pi of the six nodes of the upper ring in the workpiece coordinate system can be calculated as follows (7):

[0090] (7)

[0091] Coordinates Q of the six nodes of the lower ring in the workpiece coordinate system i , as shown in formula (8):

[0092] (8)

[0093] Based on this, at the scanning time point t, the length of the 6 connecting rods is d i (t), as shown in formula (9):

[0094] (9)

[0095] where |…| represents the Euclidean distance between two spatial points.

[0096] The above parameters L and θ are adjustable. In one possible implementation, an optimization index is added to determine the values of L and θ so that the length of the six connecting rods at time t changes as little as possible compared with that at time t-1, thereby improving the stability of the welding gun. Specifically, the optimization formula for L and θ can be referred to the following formula (10):

[0097] (10)

[0098] Based on the values of L and θ determined above, as well as the coordinate limitations of each mechanical structure, the target motion path information is inversely solved to obtain the control instructions for each connecting rod. The control instructions for each connecting rod are sent to the controller to control the welding gun and achieve high-quality welding.

[0099] In summary, the welding gun motion control method provided in the embodiments of the present application uses a preset welder motion simulation algorithm to digitize the welding gun motion of a welder of the same groove type as the groove to be welded. The result of the weighted summation of multiple Gaussian basis functions is used as the welding gun motion state. Based on this, the initial welding gun motion state corresponding to each scanning time point is determined during the process of the simulated welder welding from the starting position to the end position of the groove to be welded.

[0100] Compared with the existing technology that controls the movement of the welding gun based on solidified code, this application converts the welder's welding action into data form to control the movement of the welding gun, and controls the welding gun based on the data in this data form, so that the welding gun can reproduce the welder's welding action, better meet the operator's welding needs, and achieve better welding results.

[0101] Next, other possible implementations of a welding gun motion control method provided in an embodiment of the present application are described through the following embodiments.

[0102] In one possible implementation, the implementation method of step S120 may also include: calling a preset welder motion simulation algorithm, and determining the welding gun position and the welding gun relative posture corresponding to each scanning time point in the process of the welding gun moving from the starting position to the end position according to the groove type, starting position and end position of the groove to be welded, which are counted as the initial welding gun motion state; based on the width and depth of the scanned position at each scanning time point in the geometric feature information, the initial welding gun motion state is adjusted respectively to obtain the target welding gun motion state corresponding to each scanning time point.

[0103] Among them, the implementation of the step of "calling the preset welder action imitation algorithm, and determining the welding gun position and the welding gun relative posture corresponding to each scanning time point in the process of the welding gun moving from the starting position to the end position according to the groove type, starting position and end position of the groove to be welded, and counting them as the initial welding gun movement state" can refer to the description corresponding to the above-mentioned step S120, which will not be repeated here.

[0104] On this basis, considering that due to differences in welding workpieces and workpiece materials, even if the groove type or groove shape is the same, the actual geometric dimensions of the groove may not be exactly the same, if only the preset welder action simulation algorithm is used to simulate the welder's welding action based on the groove type, starting position, and end position to generate the welding path for the groove to be welded, it may not be fully adapted to the actual situation of the groove to be welded. Based on this, the embodiment of the present application corrects the initial welding gun motion state corresponding to each scanning time point obtained by the preset welder action simulation algorithm based on the width and depth of the groove to be welded at each scanning time point, so that the corrected target welding gun motion state is more adapted to the actual situation of the groove to be welded.

[0105] The width of the scanned position at each scanning time point is referenced to adjust the swing amplitude of the initial welding gun motion state corresponding to that scanning time point. For example, in wide grooves, the swing amplitude of the welding gun is increased to fully cover the area to be welded; in narrow grooves, the swing amplitude of the welding gun is reduced to prevent weld deposition outside the weld. The depth of the scanned position at each scanning time point is referenced to adjust the movement speed of the initial welding gun motion state corresponding to that scanning time point. For example, in deep grooves, the movement speed of the welding gun is reduced to ensure full penetration; in shallow grooves, the movement speed of the welding gun is increased to prevent weld leaks.

[0106] Optionally, the adjustment range of the swing amplitude and the moving speed can be pre-set. For example, if the width increases by 1 mm relative to the preset standard width, the swing amplitude increases by 50%; if the depth decreases by 0.5 mm relative to the preset standard depth, the moving speed increases by 20%.

[0107] In one possible implementation, the width and depth are converted into functions of the same type as the above equations (1), (2), and (3), so as to facilitate unified digital operations, simplify the state adjustment method, and improve the efficiency of path generation. Specifically, it can include: determining a time scaling factor corresponding to the scanning time point based on the width of the scanning time point, the time scaling factor representing the degree of scaling of the welding gun's swing amplitude under the width; determining a scale scaling factor corresponding to the scanning time point based on the depth of the scanning time point, the scale scaling factor representing the degree of scaling of the welding gun's movement speed under the depth; and correcting the welding gun swing amplitude and the welding gun movement speed of the initial welding gun motion state according to the time scaling factor and scale scaling factor corresponding to the scanning time point to obtain the target welding gun motion state corresponding to the scanning time point.

[0108] Get the groove width at each scanning time point of the laser scan and groove depth , when the welding gun moves to the scanning time point t j When the position corresponding to the moment is reached, the time scaling factor is calculated according to the groove depth. , k1 is a coefficient greater than 0, the time scaling factor is proportional to the groove depth; according to the groove width Calculate the scale factor , k2 is a coefficient greater than 0, and the scale scaling factor is proportional to the groove width.

[0109] Based on the time scaling factor and scale scaling factor corresponding to each scanning time point, the initial welding gun motion state at each scanning time point is corrected to obtain the second-order derivative of the welding gun motion state as follows (11):

[0110] (11)

[0111] Integrate equation (11) according to equation (12) to obtain the scanning time point t j The target welding gun motion state y(t j ), determine whether the target welding gun motion state corresponding to each time scan point has been determined. If so, stop all operations, summarize the target welding gun motion state corresponding to each time scan point, and execute step S140. Otherwise, return to calculate the time scaling factor and scale scaling factor of the next time scan point.

[0112] (12)

[0113] Based on this, the correction result of the initial welding gun motion state at each time scan point is obtained and used as the target welding gun operation state at each time scan point, thereby generating the target motion path in step S130. This application corrects the simulation results based on the width and depth of the groove, making the welding of the welding gun more adaptable to the current groove welding state and more flexible.

[0114] An embodiment of the present application also provides a computer program product including computer-readable instructions. When the computer-readable instructions are executed on an electronic device, the electronic device implements any one of the welding gun motion control methods provided in the embodiments of the present application.

[0115] A computer-readable storage medium is also provided in an embodiment of the present application. The storage medium carries one or more computer programs. When the one or more computer programs are executed by a processor of a welding gun motion control system, the welding gun motion control system can implement any one of the welding gun motion control methods provided in the embodiments of the present application.

[0116] Through the description of the above embodiments, those skilled in the art can clearly understand that the present application can be implemented by means of software plus necessary general hardware, and of course can also be implemented by special hardware including application-specific integrated circuits, special CPUs, special memories, special components, etc. In general, all functions performed by computer programs can be easily implemented with corresponding hardware, and the specific hardware structures used to implement the same function can also be diverse, such as analog circuits, digital circuits or special circuits, etc. However, for the present application, software program implementation is a better implementation method in most cases. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art can be embodied in the form of a software product, which is stored in a readable storage medium, such as a computer's floppy disk, USB flash drive, mobile hard disk, ROM, RAM, magnetic disk or optical disk, etc., and includes a number of instructions to enable a computer device (which can be a personal computer, training equipment, or network equipment, etc.) to execute the methods described in each embodiment of the present application.

[0117] In the above embodiments, all or part of the embodiments may be implemented by software, hardware, firmware, or any combination thereof. When implemented by software, all or part of the embodiments may be implemented in the form of a computer program product.

[0118] The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions can be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from a website, a computer, a training device or a data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) mode to another website, a computer, a training device or a data center. The computer-readable storage medium can be any available medium that a computer can store or a data storage device such as a training device, a data center, etc. that includes one or more available media integrations. The available medium can be a magnetic medium, (e.g., a floppy disk, a hard disk, a tape), an optical medium (e.g., a DVD), or a semiconductor medium (e.g., a solid-state drive (SSD)).

[0119] Finally, it should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article, or device comprising the element.

[0120] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0121] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present application. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application is not limited to the embodiments shown herein, but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A welding gun motion control method, characterized in that: A processor for a welding gun motion control system, wherein the welding gun motion control system further comprises at least a welding gun and a controller for controlling the welding gun, including: Acquiring geometric feature information of the groove to be welded, the geometric feature information at least including: scanning the groove to be welded at a preset scanning speed, and obtaining the starting position and the ending position of the groove to be welded; calling a preset welder motion simulation algorithm to determine a target welding gun motion state corresponding to each scanning time point during the movement of the welding gun from the starting position to the end position, wherein the preset welder motion simulation algorithm is an algorithm for converting the welder's welding motion into a weighted sum of multiple Gaussian basis functions, wherein the welder's welding motion is the welding gun motion of the welder during the process of welding a workpiece sample having a groove type consistent with the groove to be welded, and the Gaussian basis function is a state function simulating the welding gun motion; Summarizing the target welding gun motion state corresponding to each scanning time point to generate target motion path information of the welding gun moving from the starting position to the end position; A welding gun control instruction including the target motion path information is generated, and the welding gun control instruction is sent to the controller.

2. The welding gun motion control method according to claim 1, characterized in that: The calling of a preset welder motion simulation algorithm to determine the target welding gun motion state corresponding to each scanning time point during the process of the welding gun moving from the starting position to the end position includes: Acquiring reference motion path information, the reference motion path information being a motion path of the welding gun under the welder's operation, collected in advance from a process in which the welder welds a workpiece sample, the workpiece sample being a groove of the same type as the groove to be welded, the reference motion path information including: a welding gun position and a relative posture of the welding gun corresponding to each welding time point of the workpiece sample, the welding time point being a time point when the workpiece sample is welded at a welding speed consistent with the scanning speed; Based on the reference motion path information, data fitting is performed on the welding gun position and the relative posture of the welding gun to construct a dynamic system corresponding to the motion degrees of freedom, wherein the dynamic system includes a plurality of predefined Gaussian basis functions and their weight coefficients, and the Gaussian basis functions and their weight coefficients continuously act during the motion process; Using each of the Gaussian basis functions and their weight coefficients, a weighted sum is performed on a plurality of the Gaussian basis functions to obtain a welding gun motion state between the starting position and the end position, including a target welding gun motion state corresponding to each of the scanning time points.

3. The welding gun motion control method according to claim 2, characterized in that: The obtaining of reference motion path information includes: Acquiring workpiece information of the workpiece sample and motion path information of the welding gun captured by a motion capture device during a process in which a welder operates a welding gun to weld the workpiece sample, wherein the motion path information includes: the welding gun position and the welding gun initial posture at each welding time point, and the workpiece information includes: the workpiece position and the workpiece posture; Based on the workpiece posture and the welding gun initial posture, a welding gun relative posture corresponding to the welding gun initial posture is determined, where the welding gun relative posture is a motion posture of the welding gun relative to the workpiece sample.

4. The welding gun motion control method according to claim 1, characterized in that: The calling of a preset welder motion simulation algorithm to determine the target welding gun motion state corresponding to each scanning time point during the process of the welding gun moving from the starting position to the end position includes: Calling a preset welder motion simulation algorithm, based on the groove type, starting position, and end position of the groove to be welded, determining the welding gun position and welding gun relative posture corresponding to each scanning time point during the movement of the welding gun from the starting position to the end position, and counting them as the initial welding gun motion state; According to the width and depth of the scanned position at each scanning time point in the geometric feature information, the initial welding gun motion state is adjusted respectively to obtain the target welding gun motion state corresponding to each scanning time point.

5. The welding gun motion control method according to claim 4, characterized in that: The initial welding gun motion state is adjusted according to the width and depth of the scanned position at the scanning time point to obtain the target welding gun motion state corresponding to each scanning time point, including: Determining a time scaling factor corresponding to the scanning time point based on the width at the scanning time point, the time scaling factor representing a scaling degree of the swing amplitude of the welding gun at the width; Determining, based on the depth at the scanning time point, a scale scaling factor corresponding to the scanning time point, wherein the scale scaling factor represents a scaling degree of a moving speed of the welding gun at the depth; According to the time scaling factor and the scale scaling factor corresponding to the scanning time point, the welding gun swing amplitude and the welding gun movement speed of the initial welding gun motion state are corrected to obtain the target welding gun motion state corresponding to the scanning time point.

6. The welding gun motion control method according to claim 1, characterized in that: The generating of the welding gun control instruction including the target motion path information includes: identifying a welding gun type of the welding gun; Acquire a mechanical structure corresponding to the welding gun type, where the mechanical structure is a structure for manipulating the movement of the welding gun; According to an inverse kinematics solution algorithm, the target motion path information is converted into a control instruction suitable for the mechanical structure.

7. The welding gun motion control method according to any one of claims 1 to 6, characterized in that: The target welding gun motion state includes at least: welding gun position, welding gun posture, welding gun moving speed and welding gun swing amplitude.

8. A computer program product, characterized in that The method comprises computer-readable instructions, which, when executed on an electronic device, enable the electronic device to implement the welding gun motion control method according to any one of claims 1 to 7.

9. A welding gun motion control system, characterized in that: include: A welding gun, a processor, and a controller for controlling said welding gun; The processor is used to implement any step of the welding gun motion control method according to any one of claims 1 to 7; The controller is used to receive the welding gun control instruction sent by the processor and control the operation of the welding gun according to the welding gun control instruction.

10. A computer storage medium, characterized in that The storage medium carries one or more computer programs. When the one or more computer programs are executed by a processor of a welding gun motion control system, the welding gun motion control system can implement the welding gun motion control method according to any one of claims 1 to 7.

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