A welding swing trajectory construction method, a robot, and a storage medium

Abstract

The application discloses a kind of welding swing trajectory construction methods, comprising the following steps: receiving the welding task point position input by host computer, the task point position includes movement type, swing type and movement parameter;According to movement type, swing type and switching continuity, the task point position with same movement parameter, same swing type and front and rear end point connection is divided into the same group, forms at least one task point position group;For each task point position group, generate basic movement section based on the movement type of task point position in group, and insert switching section at the connection of adjacent basic movement section, form continuous combined trajectory;Based on the periodic characteristics of swing type, periodic offset calculation is carried out along the advancing direction of combined trajectory, and the discrete point position after offset is converted into movement instruction executable by robot, and welding swing trajectory is realized by the combination of the movement instruction.

Description

Technical Field

[0001] This invention relates to the field of robotics, and more specifically, to a method for constructing welding oscillation trajectories, a robot, and a storage medium. Background Technology

[0002] In welding operations, oscillating motion is a key element in improving welding quality, aiming to optimize the fusion of the weld pool and ensure uniform distribution of the solder. Currently, collaborative robots typically only possess basic functions such as linear motion (MoveL) and circular motion (MoveC), while complex oscillating trajectories such as zigzag and trapezoidal oscillations required for welding often necessitate the development of dedicated motion commands or modifications to the robot's underlying control system.

[0003] Current technologies suffer from the following problems: directly adding swing commands to the robot's lower-level machine leads to control system redundancy and increased maintenance costs; some solutions rely on real-time offset compensation algorithms, requiring strict matching of the robot's interpolation cycle, which places high demands on developers; swing trajectories designed for specific weldments (such as combinations of curved and planar surfaces) are difficult to adapt to other scenarios. CN114985868B, a swing arc welding method and welding robot, proposes a swing welding trajectory planning method based on spatial vector superposition. This method generates a composite motion trajectory in a dynamic local coordinate system by superimposing the main motion vector and the component motion vectors, based on the principle of spatial vector superposition. However, this solution relies on the interpolation algorithm of the robot control system and does not achieve decoupling between trajectory calculation and the robot body, still resulting in high system coupling. Furthermore, existing technologies mostly focus on single swing modes, with limited attention to mode switching, and are difficult to meet the requirements of complex welds. Summary of the Invention

[0004] To address the aforementioned problems, this invention provides a method for constructing welding oscillation trajectories, solving the issues of existing technologies where welding oscillation trajectory planning relies on robot underlying development, resulting in high system complexity and poor scalability. The method includes the following steps:

[0005] S1. Receive the welding task point input from the host computer, wherein the task point includes motion type, swing type and motion parameters;

[0006] S2. Based on the motion type, swing type and transition continuity, the task points with the same motion parameters, the same swing type and the connection between the front and rear endpoints are divided into the same group to form at least one task point group.

[0007] S3. For each task point group, generate basic motion segments based on the motion type of the task points within the group, and insert transition segments at the junctions of adjacent basic motion segments to form a continuous combined trajectory.

[0008] S4. Based on the periodic characteristics of the swing type, perform periodic offset calculations along the forward direction of the combined trajectory, convert the offset discrete points into motion commands that the robot can execute, and realize the welding swing trajectory through the combination of the motion commands.

[0009] As a preferred technical solution, the motion type is a straight line or a circular arc, the swing type is at least one of a Z-shaped pendulum, a trapezoidal pendulum, a crescent pendulum, or a circular pendulum, and the motion parameters include speed, transition radius, and task point ID.

[0010] As a preferred technical solution, the basic motion segment is a straight line or a circular arc trajectory, and the transition segment is a circular arc or a Bézier curve trajectory.

[0011] As a preferred technical solution, the method for generating the transition segment includes:

[0012] When adjacent basic motion segments are both straight lines corresponding to task points, the transition segment is a circular arc trajectory.

[0013] When adjacent basic motion segments are respectively the trajectories corresponding to straight task points and circular task points, or both are the trajectories corresponding to circular task points, the transition segment is a Bézier curve trajectory.

[0014] When inserting a transition segment, a dual constraint check is performed on the transition radius of the current task point. If either constraint condition is not met, a dynamic adjustment mechanism is activated.

[0015] As a preferred technical solution, the dual constraint test includes both geometric constraint testing and dynamic constraint testing.

[0016] The geometric constraints are expressed as follows:

[0017] in, For the transition radius, The length of an adjacent straight line or the chord length of a circular arc;

[0018] The dynamic constraints are expressed as follows:

[0019] in, For speed, This is the maximum permissible normal acceleration.

[0020] As a preferred technical solution, step S4 includes:

[0021] Based on the periodic characteristics of the oscillation type, points are selected along the forward direction of the combined trajectory at preset step lengths;

[0022] The sampling points are periodically offset, and the offset direction is determined by the forward direction of the combined trajectory and the direction of the tool axis.

[0023] The offset discrete points are connected by linear or circular motion and returned to the host computer to be converted into motion commands that the robot can execute.

[0024] As a preferred technical solution, in step S4, when the welding oscillation trajectory involves different oscillation types, cross-oscillation type planning motion is performed for adjacent task points.

[0025] As a preferred technical solution, the cross-swing type planning motion includes the following steps:

[0026] Based on the motion parameters of the current swing type task point and the periodic characteristics of the forward and backward swing types, the length of the transition zone for switching is planned;

[0027] Within the transition zone, interpolation calculations are performed on the amplitude, frequency, and dwell ratio parameters of the forward and backward swing types to achieve gradual parameter changes;

[0028] Based on the end phase of the current swing type, set the initial phase of the target swing type to achieve continuity of the forward and backward swing trajectories in terms of position and velocity;

[0029] Based on the transition radius of the current swing type task point, the amplitude value of the current swing type is limited;

[0030] When a motion command is executed, calculate whether the sum of the centripetal acceleration of the main trajectory and the lateral acceleration of the swing exceeds a threshold. If it exceeds the threshold, reduce the amplitude or frequency of the swing type.

[0031] As a preferred technical solution, the present invention also provides a robot that includes the above-described method for constructing welding oscillation trajectories.

[0032] As a preferred technical solution, the present invention also provides a computer-readable storage medium having a computer program stored thereon, characterized in that the computer program implements the above-described method when executed by a processor.

[0033] Compared with the prior art, the beneficial effects of this invention are:

[0034] 1. By receiving and classifying task points from the host computer, a combined trajectory containing basic motion segments and transition segments is generated. The offset points are then determined based on the periodic characteristics of the oscillation type, ultimately converting the trajectory into basic robot motion commands. This invention eliminates the need to modify the robot's underlying architecture, achieving complex oscillations through combinations of basic motions. This improves the stability of the welding system, reduces the development difficulty of welding-related functions, and ensures functional integrity.

[0035] 2. The transition radius of the transition section is subject to dual constraint testing to improve the overall reliability of welding trajectory planning, process quality adaptability and equipment control safety.

[0036] 3. Introducing cross-oscillation type planning motion at the oscillation type switching point significantly improves the trajectory smoothness, process adaptability, and overall welding quality of weld seams when the welding oscillation trajectory involves different oscillation types. Attached Figure Description

[0037] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0038] Figure 1 This is a flowchart illustrating the welding oscillation trajectory construction method of the present invention;

[0039] Figure 2 A state diagram of the workpiece after welding using the welding oscillation trajectory construction method of the present invention;

[0040] Figure 3 This is a schematic diagram of the periodic offset of the Z-shaped oscillation in the welding oscillation trajectory construction method of the present invention;

[0041] Figure 4 This is a schematic diagram of the Z-shaped oscillation in the welding oscillation trajectory construction method of the present invention;

[0042] Figure 5 This is a schematic diagram of the Z-shaped swing trajectory effect in the welding swing trajectory construction method of the present invention;

[0043] Figure 6 This is a schematic diagram of the trapezoidal oscillation periodic offset in the welding oscillation trajectory construction method of the present invention;

[0044] Figure 7 This is a schematic diagram of the trapezoidal oscillation in the welding oscillation trajectory construction method of the present invention;

[0045] Figure 8 This is a schematic diagram of the trapezoidal swing trajectory effect in the welding swing trajectory construction method of the present invention;

[0046] Figure 9 This is a schematic diagram of the periodic offset of the crescent-shaped oscillation in the welding oscillation trajectory construction method of the present invention;

[0047] Figure 10 This is a schematic diagram of the crescent-shaped oscillation in the welding oscillation trajectory construction method of the present invention;

[0048] Figure 11 This is a schematic diagram of the crescent-shaped oscillation trajectory effect in the welding oscillation trajectory construction method of the present invention;

[0049] Figure 12 This is a schematic diagram of the periodic offset of the circular oscillation in the welding oscillation trajectory construction method of the present invention;

[0050] Figure 13 This is a schematic diagram of the circular oscillation in the welding oscillation trajectory construction method of the present invention;

[0051] Figure 14 This is a schematic diagram of the circular oscillation trajectory effect in the welding oscillation trajectory construction method of the present invention. Detailed Implementation

[0052] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0053] It should be noted that the terms "first" and "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0054] Figure 1 This is a flowchart of a welding oscillation trajectory construction method provided by an embodiment of the present invention. The method is executed by a collaborative robot, such as... Figure 1 As shown, it includes the following steps:

[0055] S1. Receive the welding task point input from the host computer, wherein the task point includes motion type, swing type and motion parameters;

[0056] S2. Based on the motion type, swing type and transition continuity, the task points with the same motion parameters, the same swing type and the connection between the front and rear endpoints are divided into the same group to form at least one task point group.

[0057] S3. For each task point group, generate basic motion segments based on the motion type of the task points within the group, and insert transition segments at the junctions of adjacent basic motion segments to form a continuous combined trajectory.

[0058] S4. Based on the periodic characteristics of the swing type, perform periodic offset calculations along the forward direction of the combined trajectory, convert the offset discrete points into motion commands that the robot can execute, and realize the welding swing trajectory through the combination of the motion commands.

[0059] In a preferred embodiment, the motion type is a straight line or an arc, the oscillation type is at least one of a Z-shaped pendulum, a trapezoidal pendulum, a crescent pendulum, or a circular pendulum, and the motion parameters include speed, transition radius, and task point ID. Figure 2 These are workpiece state diagrams after welding using the welding oscillation trajectory construction method of this invention, showing trapezoidal oscillation, Z-shaped oscillation, circular oscillation, and crescent oscillation in sequence. The task point ID is key identification data stored in the task point, its main function being to provide the traceability basis for the motion segment to which the discrete point belongs; that is, the task point ID is used to uniquely identify each task point and maintain association among discrete points.

[0060] In a preferred embodiment, the basic motion segment is a straight line or a circular arc trajectory, and the transition segment is a circular arc or a Bézier curve trajectory.

[0061] In a preferred embodiment, the transition segment is generated in the following manner:

[0062] When adjacent basic motion segments are both straight lines corresponding to task points, the transition segment is a circular arc trajectory.

[0063] When adjacent basic motion segments are respectively the trajectories corresponding to straight task points and circular task points, or both are the trajectories corresponding to circular task points, the transition segment is a Bézier curve trajectory.

[0064] When inserting a transition segment, a dual constraint check is performed on the transition radius of the current task point. If either constraint condition is not met, a dynamic adjustment mechanism is activated.

[0065] In a preferred embodiment, the dual constraint check includes a geometric constraint check and a dynamic constraint check.

[0066] The geometric constraints are expressed as follows:

[0067] in, For the transition radius, The length of an adjacent straight line or the chord length of a circular arc;

[0068] The dynamic constraints are expressed as follows:

[0069] in, For speed, This is the maximum permissible normal acceleration.

[0070] In a preferred embodiment, the dynamic adjustment mechanism refers to:

[0071] When geometric constraints are not met, the transition radius is reduced to the maximum value allowed by the geometric constraints; when dynamic constraints are not met, the motion speed is first reduced, and if it still cannot be met, the transition radius is increased to the minimum value allowed by the dynamic constraints.

[0072] If the above adjustments still fail to meet the operational requirements, the transfer radius of the current task location will be set to zero, causing it to degenerate into a normal location and continue operating.

[0073] More specifically, the dynamic adjustment mechanism includes:

[0074] If the transition radius exceeds the upper limit of the geometric constraint, it is reduced to the maximum value allowed by the geometric constraint; if the transition radius is lower than the lower limit of the dynamic constraint, it is increased to the minimum value that meets the dynamic requirements.

[0075] Among these, geometric constraints have higher priority than dynamic constraints. When geometric constraints are not met, the transition radius should be reduced first; when only dynamic constraints are not met, the movement speed should be reduced first, rather than directly increasing the radius, to avoid the transition arc exceeding the weld range.

[0076] If the above adjustments still fail to meet the operating conditions, the transfer radius of the current point will be set to zero, causing it to degenerate into a normal point and continue to operate, ensuring that the system can still operate stably under extreme conditions.

[0077] It should be noted that under geometric constraints, if the transition radius is greater than half the length of the adjacent straight line or the chord length of the arc, the transition segment of the arc or Bézier curve trajectory cannot be added to the motion trajectory, and it will likely overlap with adjacent points or even exceed the predetermined motion trajectory. In particular, when the angle between adjacent path segments is close to 180° (approximately a straight line), an excessively large transition radius will cause the arc to extend beyond the weld area, thus affecting the welding quality. In this case, the transition radius should be set to zero, and the current point should be treated as a normal point to maintain the continuity of the motion trajectory and the stability of the process.

[0078] In dynamic constraints, if the constraint is not met, the robot may exceed its load capacity when turning, affecting its motion stability.

[0079] This invention performs dual constraint checks on the transition radius of the transition section and sets clear priority rules and automatic scaling strategies, so that the dynamic adjustment of the transition radius can ensure that the welding trajectory does not cross the boundary or overlap, while taking into account the stability of robot motion and load safety. Its anomaly handling mechanism further enhances the robustness of the system, ensuring that it can still maintain continuous operation under extreme path conditions, thereby improving the overall reliability of welding trajectory planning, process quality adaptability and equipment control safety.

[0080] In a preferred embodiment, step S4 includes:

[0081] Based on the periodic characteristics of the oscillation type, points are selected along the forward direction of the combined trajectory at preset step lengths;

[0082] The sampling points are periodically offset, and the offset direction is determined by the forward direction of the combined trajectory and the direction of the tool axis.

[0083] The offset discrete points are connected by linear or circular motion and returned to the host computer to be converted into motion commands that the robot can execute.

[0084] In a preferred embodiment, the step of selecting points along the forward direction of the combined trajectory at preset step lengths according to the periodic characteristics of the oscillation type; periodically offsetting the selected points, the offset direction being jointly determined by the forward direction of the combined trajectory and the tool axis direction; and connecting the offset discrete points in a linear or circular motion manner, specifically including:

[0085] Figure 3 This is a schematic diagram of the periodic offset of the Z-shaped oscillation in the welding oscillation trajectory construction method of the present invention, as shown below. Figure 3As shown, for the Z-shaped oscillation: the trajectory is divided into four equal-length steps according to the period, and the amplitude value is successively offset to zero, negative amplitude value, and zero along the vertical axis of the motion direction, forming a "Z"-shaped linear motion combination. Specifically: for the Z-shaped oscillation, one period can be divided into four steps, each step length is s. Points are taken and offset according to the step length along the planned curve trajectory. The starting point of the trajectory is obtained at the beginning and marked as point 0. Then, according to the step length, the points on the curve are offset sequentially. The offset direction is determined by the y-axis direction of the coordinate system, which is jointly determined by the forward direction and the tool z-axis direction. Specifically, the first step offsets h to obtain point 1, the second step offsets 0 to obtain point 2, the third step offsets -h to obtain point 3, the fourth step offsets 0 to obtain point 4, and so on until the end of the trajectory. The points are connected by linear motion to obtain the discrete offset points of the Z-shaped oscillation. Between points, 0-1 represents linear motion; 1-2 represents linear motion; 2-3 represents linear motion; 3-4 represents linear motion, and so on until the last offset point. This transforms the Z-shaped oscillation into a series of linear movements. In other words, adjacent points in the Z-shaped oscillation are connected by linear motion commands. Through the periodic action of "bias-align-reverse bias-align," the complex Z-shaped oscillation trajectory is transformed into a basic combination of linear motions that the robot can execute. The corresponding Z-shaped oscillations in the two linear task points and the two circular task points are as follows: Figure 4 As shown. The offset discrete points are converted into motion commands executable by the robot. The welding oscillation trajectory is achieved by combining these motion commands, such as... Figure 5 As shown.

[0086] Figure 6 This is a schematic diagram of the trapezoidal oscillation periodic offset in the welding oscillation trajectory construction method of the present invention, as shown below. Figure 6As shown, for trapezoidal oscillation: the trajectory is divided into 6 steps according to the period, with step lengths of s, l, s, s, l, s respectively. The amplitude is shifted sequentially along the vertical axis: offset by a value, maintained by a value, zero, negative amplitude, maintained negative amplitude, and zero, forming a trapezoidal linear motion combination. Specifically: for trapezoidal oscillation: one period can be divided into 6 steps, with step lengths of s, l, s, s, l, s respectively. Points are taken and offset along the planned curve trajectory according to the step length. The starting point of the trajectory is obtained at the initial moment and marked as point 0. Then, according to the step length, the points on the curve are offset sequentially. The offset direction is determined by the forward direction and the tool z-axis direction, which is the y-axis direction of the coordinate system. Specifically, the first step is a step length of s with an offset of h to obtain point 1. The second step is a step length of l with the offset still h to obtain point 2, forming the upper base of the trapezoid. The third step is a step length of s with the offset zeroed to obtain point 3, completing the transition from the upper base to the lower base. The fourth step is a step length of s with an offset of -h to obtain point 4. The fifth step is a step length of l with the offset -h to obtain point 5, forming the lower base of the trapezoid. The sixth step is a step length of s with the offset zeroed to obtain point 6, returning to the original trajectory. This completes one cycle, and then the next cycle begins. The cycle offsets are executed sequentially according to the pattern until the trajectory ends, resulting in discrete offset points for the trapezoidal oscillation. Between points, 0-1 represents linear motion; 1-2 represents linear motion; 2-3 represents linear motion; 3-4 represents linear motion; 4-5 represents linear motion; 5-6 represents linear motion; and so on until the last offset point. This transforms the trapezoidal oscillation into a series of linear motions. In other words, adjacent points of the trapezoidal oscillation are connected by linear motion commands. Through a periodic action of "bias-hold-return-anti-bias-hold-return," the trapezoidal oscillation is transformed into a basic linear motion combination that the robot can execute. In two linear task points and two circular task points, the corresponding trapezoidal oscillations are as follows: Figure 7 As shown. The offset discrete points are converted into motion commands executable by the robot. The welding oscillation trajectory is achieved by combining these motion commands, such as... Figure 8 As shown.

[0087] Figure 9 This is a schematic diagram of the periodic offset of the crescent-shaped oscillation in the welding oscillation trajectory construction method of the present invention, as shown below. Figure 9As shown, for the crescent-shaped oscillation: the trajectory is divided into four equal-length steps according to the period, and the amplitude value, secondary amplitude value, negative amplitude value, and negative secondary amplitude value are offset sequentially along the vertical axis. The offset points are connected by circular arc motion to form a crescent-shaped trajectory. Specifically: for the crescent-shaped oscillation, one period can be divided into four steps, each with a length of s. Points are taken and offset along the planned curve trajectory step by step. The starting point of the trajectory is obtained at the beginning and marked as point 0. At this time, point 0 needs to be offset by h. Then, according to the length of the step, the points on the curve are offset sequentially. The offset direction is the y-axis direction in the coordinate system determined by the forward direction and the tool z-axis direction. Specifically, the first step length of s offsets the point by h' to obtain point 1, the second step length of s offsets the point by -h to obtain point 2, the third step length of s offsets the point by -h' to obtain point 3, and the fourth step length of s offsets the point by h to obtain point 4. This completes one cycle, and the next cycle begins. The cycle offsets are executed sequentially according to a pattern until the trajectory ends at the point where the discrete offset points of the crescent oscillation are obtained. Between these points, 0-1-2 represents a circular motion, 2-3-4 represents a circular motion, and so on until the last offset point. This transforms the crescent oscillation into a series of circular motions. The corresponding crescent oscillations at the two linear task points and the two circular task points are as follows: Figure 10 As shown. The offset discrete points are converted into motion commands executable by the robot. The welding oscillation trajectory is achieved by combining these motion commands, such as... Figure 11 As shown.

[0088] Figure 12 This is a schematic diagram of the periodic offset of the circular oscillation in the welding oscillation trajectory construction method of the present invention, as shown below. Figure 12As shown, for circular oscillation: the trajectory is divided into 8 steps according to the period, with step lengths of s, s, s, s, -s', -s', -s', -s', -s'. The amplitude values ​​are offset sequentially along the vertical axis: amplitude value, amplitude value, amplitude value, zero, negative amplitude value, negative amplitude value, negative amplitude value, zero. A circular trajectory is formed through the combination of multiple circular arc movements. Specifically: for circular oscillation, one period can be divided into 8 steps, each with a length of s, s, s, s, -s', -s', -s', -s'. Points are taken sequentially along the planned curve trajectory according to the step length. The starting point of the trajectory is obtained at the initial moment and marked as point 0. Then, according to the step length, the points on the curve are offset sequentially, with the offset direction being the y-axis direction in the coordinate system determined by the forward direction and the tool's z-axis direction. The first step, with a length of 's', offsets the point by 'h', resulting in point 1. The second step, also with a length of 's', offsets the point by 'h', resulting in point 2. The third step, with a length of 's', offsets the point by 'h', resulting in point 3. The fourth step, with a length of 's', offsets the point by '0', resulting in point 4. The fifth step, with a length of '-s', offsets the point by '-h', resulting in point 5. The sixth step, with a length of '-s', offsets the point by '-h', resulting in point 6. The seventh step, with a length of '-s', offsets the point by '-h', resulting in point 7. The eighth step, with a length of '-s', offsets the point by '0', resulting in point 8. This completes one cycle, and the next cycle begins. The offsets are executed sequentially according to this pattern until the trajectory ends at the desired discrete offset point, resulting in the crescent-shaped oscillation. Between points, 0-1-2 represents a circular motion; 2-3-4 represents a circular motion; 4-5-6 represents a circular motion; 6-7-8 represents a circular motion; and so on until the last offset point. This transforms the crescent-shaped oscillation into a series of circular motions. The corresponding circular oscillations between the two straight-line task points and the two circular task points are as follows: Figure 13 As shown. The offset discrete points are converted into motion commands executable by the robot. The welding oscillation trajectory is achieved by combining these motion commands, such as... Figure 14 As shown.

[0089] In a preferred embodiment, the discrete points are stored in a structure, which includes target points, auxiliary points, motion type, velocity, acceleration, and transition radius. This structure is transmitted back to the host computer via a communication protocol and encapsulated as robot motion commands. The structure is a standardized data structure used to store discrete welding oscillation point data; the communication protocol is XML-RPC.

[0090] In a preferred embodiment, in step S4, when the welding oscillation trajectory involves different oscillation types, cross-oscillation type planning motion is performed for adjacent task points.

[0091] In a preferred embodiment, the planning of the cross-oscillation type includes transition zone length calculation, amplitude and frequency gradient processing, phase continuity assurance, amplitude and radius linkage control, and synthetic acceleration constraint check.

[0092] In a preferred embodiment, the cross-swing type planning motion includes the following steps:

[0093] Based on the motion parameters of the current swing type task point and the periodic characteristics of the forward and backward swing types, the length of the transition zone for switching is planned;

[0094] Within the transition zone, interpolation calculations are performed on the amplitude, frequency, and dwell ratio parameters of the forward and backward swing types to achieve gradual parameter changes;

[0095] Based on the end phase of the current swing type, set the initial phase of the target swing type to achieve continuity of the forward and backward swing trajectories in terms of position and velocity;

[0096] Based on the transition radius of the current swing type task point, the amplitude value of the current swing type is limited;

[0097] When a motion command is executed, calculate whether the sum of the centripetal acceleration of the main trajectory and the lateral acceleration of the swing exceeds a threshold. If it exceeds the threshold, reduce the amplitude or frequency of the swing type.

[0098] In detail, the cross-swing type planning motion includes the following steps:

[0099] Based on the motion parameters of the current swing type task point and the periodic characteristics of the preceding and following swing types, the length of the transition zone used for switching is planned, expressed as:

[0100] in, This represents the speed of travel for that segment. The period is for the oscillation type. , For adjustment coefficients, This is the minimum transition band length set.

[0101] The above calculation of the transition zone length ensures that the switching process smoothly covers multiple oscillation cycles.

[0102] Within the transition zone, S-curve interpolation is performed on the amplitude A, frequency f, and dwell ratio D of the forward and backward oscillation types to achieve gradual parameter changes, as shown below:

[0103] in, , , This is a normalized arc length parameter along the trajectory direction, used to ensure that the amplitude and frequency do not change abruptly.

[0104] Based on the ending phase of the current swing type, the initial phase of the target swing type is set to achieve continuity in position and velocity of the forward and backward swing trajectories, as shown below:

[0105] , in, This represents the lateral offset function, where s represents the trajectory arc length. This indicates the switching point between the forward and backward swing types.

[0106] In other words, the phase of the target swing type Based on the current phase of the swing Adjustments can prevent the robot from experiencing motion shocks at switching points.

[0107] Based on the transition radius of the current swing type task point, the amplitude value of the current swing type is limited to ensure that the swing does not extend beyond the weld seam area, as shown below:

[0108] Where B is the allowable half-width of the workpiece. For safety margin, This is the proportionality coefficient. This is the transition radius.

[0109] When a motion command is executed, whether the sum of the centripetal acceleration of the main trajectory and the lateral acceleration of the swing exceeds a threshold is calculated as follows:

[0110] in, This is the maximum allowable synthetic acceleration of the system.

[0111] If the threshold is exceeded, reduce the amplitude or frequency of the swing type, and if necessary, reduce the travel speed to ensure motion stability.

[0112] This invention introduces cross-oscillation type planning motion at the oscillation type switching point. By automatically calculating the transition zone length, using S-curves to smoothly interpolate parameters such as amplitude and frequency, and strictly maintaining phase continuity, the amplitude value and acceleration are limited, thereby achieving a natural and shock-free switching between different oscillation types. This significantly improves the trajectory smoothness, process adaptability and overall welding quality of welds when the welding oscillation trajectory involves different oscillation types.

[0113] In a preferred embodiment, the method is implemented through a host computer plug-in independent of the robot control system, which only needs to support basic linear and circular motion commands.

[0114] The present invention also provides a robot that includes the above-described method for constructing welding oscillation trajectories.

[0115] The present invention also provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the above-described welding oscillation trajectory construction method.

[0116] It should be understood that the computer-readable storage medium is any data storage device capable of storing data or programs that can subsequently be read by a computer system. Examples of computer-readable storage media include read-only memory, random access memory, CD-ROM, HDD, DVD, magnetic tape, and optical data storage devices. Computer-readable storage media can also be distributed across network-coupled computer systems, enabling computer-readable code to be stored and executed in a distributed manner. The program code contained on the computer-readable storage medium can be transmitted using any suitable medium, including but not limited to: wireless, wired, optical fiber, radio frequency (RF), or any suitable combination thereof.

[0117] In some implementations, the computer-readable storage medium may be non-transitory.

[0118] Compared to existing technologies, the welding oscillation trajectory construction method provided by this invention receives and classifies task points from a host computer, generates a combined trajectory including basic motion segments and transition segments, offsets points based on the periodic characteristics of the oscillation type, and finally converts it into basic robot motion commands. This invention does not require modification of the robot's underlying architecture, achieves complex oscillations through combinations of basic motions, improves the stability of the welding system, reduces the development difficulty of welding-related functions, and ensures functional integrity. The transition radius of the transition segment undergoes dual constraint verification, comprehensively improving the reliability of welding trajectory planning, process quality adaptability, and equipment control safety. The introduction of cross-oscillation type planning motion at oscillation type switching points significantly improves the trajectory smoothness, process adaptability, and overall welding quality of welds when the welding oscillation trajectory involves different oscillation types.

[0119] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0120] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A method for constructing a welding oscillation trajectory, characterized in that, Includes the following steps: S1. Receive the welding task point input from the host computer, wherein the task point includes motion type, swing type and motion parameters; S2. Based on the motion type, swing type and transition continuity, the task points with the same motion parameters, the same swing type and the connection between the front and rear endpoints are divided into the same group to form at least one task point group. S3. For each task point group, generate basic motion segments based on the motion type of the task points within the group, and insert transition segments at the junctions of adjacent basic motion segments to form a continuous combined trajectory. S4. Based on the periodic characteristics of the swing type, perform periodic offset calculations along the forward direction of the combined trajectory, convert the offset discrete points into motion commands that can be executed by the robot, and realize the welding swing trajectory through the combination of the motion commands. The methods for generating the transition segment include: When adjacent basic motion segments are both straight lines corresponding to task points, the transition segment is a circular arc trajectory. When adjacent basic motion segments are respectively the trajectories corresponding to straight task points and circular task points, or both are the trajectories corresponding to circular task points, the transition segment is a Bézier curve trajectory. When inserting a transition segment, a dual constraint check is performed on the transition radius of the current task point. If either constraint condition is not met, a dynamic adjustment mechanism is activated. The dual constraint test includes both geometric constraint test and dynamic constraint test. The geometric constraints are expressed as follows: in, For the transition radius, The length of an adjacent straight line or the chord length of a circular arc; The dynamic constraints are expressed as follows: in, For speed, This is the maximum permissible normal acceleration.

2. The welding oscillation trajectory construction method according to claim 1, characterized in that, The motion type is a straight line or a circular arc, the swing type is at least one of a Z-shaped pendulum, a trapezoidal pendulum, a crescent pendulum, or a circular pendulum, and the motion parameters include speed, transition radius, and task point ID.

3. The welding oscillation trajectory construction method according to claim 2, characterized in that, The basic motion segment is a straight line or a circular arc trajectory, and the transition segment is a circular arc or a Bézier curve trajectory.

4. The welding oscillation trajectory construction method according to claim 2, characterized in that, Step S4 includes: Based on the periodic characteristics of the oscillation type, points are selected along the forward direction of the combined trajectory at preset step lengths; The points are periodically offset, and the offset direction is determined by the forward direction of the combined trajectory and the direction of the tool axis. The offset discrete points are connected by linear or circular motion and returned to the host computer to be converted into motion commands that the robot can execute.

5. The welding oscillation trajectory construction method according to any one of claims 1 or 3, characterized in that, In step S4, when the welding oscillation trajectory involves different oscillation types, cross-oscillation type planning motion is performed for adjacent task points.

6. The welding oscillation trajectory construction method according to claim 5, characterized in that, The cross-swing type planning motion includes the following steps: Based on the motion parameters of the current swing type task point and the periodic characteristics of the forward and backward swing types, the length of the transition zone for switching is planned; Within the transition zone, interpolation calculations are performed on the amplitude, frequency, and dwell ratio parameters of the forward and backward swing types to achieve gradual parameter changes; Based on the end phase of the current swing type, set the initial phase of the target swing type to achieve continuity of the forward and backward swing trajectories in terms of position and velocity; Based on the transition radius of the current swing type task point, the amplitude value of the current swing type is limited; When a motion command is executed, calculate whether the sum of the centripetal acceleration of the main trajectory and the lateral acceleration of the swing exceeds a threshold. If it exceeds the threshold, reduce the amplitude or frequency of the swing type.

7. A robot, characterized in that, It is capable of performing the welding oscillation trajectory construction method as described in any one of claims 1-6.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the welding oscillation trajectory construction method according to any one of claims 1-6.

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