Workpiece surfacing control method capable of automatic avoidance

Abstract

The present application relates to the technical field of automatic surfacing control, and discloses a workpiece surfacing control method capable of automatic avoidance, aiming at solving the problems of the existing annular workpiece surfacing that cannot automatically avoid the center rectangular non-welding area, frequent manual intervention and poor avoidance precision. First, workpiece parameters and welding process parameters are acquired, a workpiece center coordinate system is established, a rotary table shaft and a radial shaft zero point are calibrated, a critical avoidance radius of the rectangular non-welding area and each vertex angle threshold are calculated, a current position of the radial shaft and a current angle of the rotary table shaft are collected in real time during the welding process, when the radial position is less than or equal to the critical avoidance radius, the actual arc stopping and starting angles of each side of the rectangle under the current number of circles are dynamically calculated based on trigonometric functions, the welding start and stop and the welding gun lifting are automatically controlled, the workpiece is fed by a set radial feed amount after each circle of surfacing is completed and the cycle is repeated until the surfacing termination radius is reached. The present application can realize full-automatic precise avoidance, improve surfacing quality and processing efficiency, and is suitable for batch production of meniscus workpieces.

Description

Technical Field

[0001] This invention relates to the field of automatic welding control technology, and in particular to a workpiece welding control method that can automatically avoid obstacles. Background Technology

[0002] In the field of wear-resistant mechanical parts processing, annular semi-meniscus-type workpieces need to have a wear-resistant layer welded on the annular area of ​​the surface, while strictly avoiding the rectangular assembly weld-free area in the center. This places high demands on both welding avoidance precision and production efficiency.

[0003] Currently, the industry mainly uses two processing methods. The first is purely manual welding, which relies entirely on the operator's visual judgment of the relative position of the welding torch and the rectangular boundary, manually controlling the start and stop of the arc. This method has a large subjective error, easily producing defects such as overflow and missed welding, resulting in poor workpiece quality consistency. Furthermore, each welding cycle requires multiple manual interventions, leading to high labor intensity. A single person can only operate one machine, making it difficult to meet the needs of mass production. The second method is semi-automatic preset program welding. The equipment can automatically run a circular welding trajectory according to preset parameters, but it lacks the ability to identify and automatically avoid rectangular weld-free areas. Operators still need to monitor in real time and manually trigger the start and stop of the arc. Because the rotation angle corresponding to the rectangular boundary changes dynamically after radial feed, manual judgment is difficult and prone to errors, failing to fundamentally solve the problems of overflow and missed welding. The degree of automation is limited, making it difficult to achieve a highly efficient production mode of one person operating multiple machines.

[0004] In addition, both of these methods require subsequent machining to remove excess solder after overflow occurs, which not only wastes solder materials but also increases secondary processing costs and lowers overall production efficiency. Summary of the Invention

[0005] The purpose of this invention is to provide a workpiece welding control method with automatic obstacle avoidance, comprising the following steps: Obtain workpiece parameters and welding process parameters. The workpiece parameters include the outer radius of the workpiece, the side length of the rectangular weld-free area in the radial direction and the side length in the tangential direction. The welding process parameters include the weld overlay start radius, weld overlay end radius, radial feed amount and angle compensation value. Establish a coordinate system with the workpiece center as the origin, calibrate the zero point position of the turntable axis and the zero point position of the radial axis, and calculate the critical avoidance radius based on the side length of the rectangular weld-free area in the radial direction and the side length in the tangential direction. The angle thresholds of each vertex of the rectangular solderless area relative to the origin of the coordinate system are calculated based on the side lengths of the rectangular solderless area in the radial direction and the side lengths in the tangential direction, and the current position of the radial axis and the current angle of the turntable axis are obtained in real time during the welding process. When it is determined that the current position of the radial axis is less than or equal to the critical avoidance radius, the actual arc-stopping angle and the actual arc-starting angle corresponding to each side of the rectangle under the current number of welding circles are calculated based on the current position of the radial axis, the side length of the rectangular solderless area along the radial direction, the side length of the rectangular solderless area along the tangential direction, and the angle compensation value. Based on the actual arc-stopping angle and the actual arc-starting angle, an arc-stopping operation is performed when the current angle of the turntable axis reaches the actual arc-stopping angle, and an arc-starting operation is performed when the current angle of the turntable axis reaches the actual arc-starting angle. When the turntable shaft completes a full rotation, the radial axis is controlled to perform a radial feed according to the radial feed amount, and the above steps are repeated until the current position of the radial axis reaches the welding termination radius.

[0006] Furthermore, the present invention also discloses an automatic obstacle avoidance workpiece welding control system, comprising: The acquisition module is used to acquire workpiece parameters and welding process parameters. The workpiece parameters include the outer radius of the workpiece, the side length of the rectangular weld-free area in the radial direction and the side length in the tangential direction. The welding process parameters include the weld overlay start radius, weld overlay end radius, radial feed amount and angle compensation value. The module is used to establish a coordinate system with the workpiece center as the origin, calibrate the zero point position of the turntable axis and the radial axis, and calculate the critical avoidance radius based on the side length of the rectangular weld-free area in the radial direction and the side length in the tangential direction. The calculation module is used to calculate the angle threshold of each vertex of the rectangular solderless area relative to the origin of the coordinate system based on the side length of the rectangular solderless area in the radial direction and the side length in the tangential direction, and to obtain the current position of the radial axis and the current angle of the turntable axis in real time during the welding process. The judgment module is used to calculate the actual arc-stopping angle and actual arc-starting angle of each side of the rectangle under the current number of welding circles when the current position of the radial axis is determined to be less than or equal to the critical avoidance radius, based on the current position of the radial axis, the side length of the rectangular solderless area along the radial direction, the side length of the rectangular solderless area along the tangential direction, and the angle compensation value. The processing module is used to perform an arc-stopping operation when the current angle of the turntable axis reaches the actual arc-stopping angle, and to perform an arc-starting operation when the current angle of the turntable axis reaches the actual arc-starting angle, based on the actual arc-stopping angle and the actual arc-starting angle. The control module is used to control the radial axis to perform a radial feed according to the radial feed amount when it is detected that the turntable axis has completed a full rotation, and repeat the above steps until the current position of the radial axis reaches the welding termination radius.

[0007] The beneficial effects of this application are as follows: Firstly, this invention enables fully automated obstacle avoidance in rectangular weld-free areas, completely eliminating manual intervention and significantly improving production efficiency. By establishing a mathematical mapping model between workpiece geometric parameters and welding torch movement positions, a programmable logic controller (PLC) collects real-time position data of the turntable axis and radial axis, automatically calculates the arc-stopping and arc-starting angles for each revolution, and autonomously completes the complete obstacle avoidance process of arc-stopping, idling, and arc-starting. The entire welding process, from arc-starting to arc-ending, is fully automated, requiring no manual control of arc-starting and stopping by operators, greatly reducing labor intensity. It can support one operator simultaneously managing multiple devices, effectively improving unit manpower output and batch production efficiency.

[0008] Secondly, this invention significantly improves avoidance accuracy and welding consistency, eliminating over-welding and under-welding defects at their source. Based on the trigonometric relationships of right triangles, and combined with the dynamic calculation of the start and stop arc angles corresponding to each side of the rectangle at the current radial position, the calculation accuracy of the avoidance boundary can reach the millimeter level, far exceeding the accuracy level of manual visual judgment. Furthermore, after each radial feed, the system automatically updates the start and stop arc angle parameters according to the new radial position, ensuring that the avoidance accuracy remains consistent throughout the entire radial range from the weld start radius to the weld end radius. This control method is unaffected by the operator's experience and condition, resulting in highly uniform weld quality across different workpieces and batches, effectively reducing welding material waste and the cost of subsequent secondary grinding.

[0009] Thirdly, the control logic of this invention is hierarchically optimized, adapting to the operating characteristics of industrial controllers and exhibiting strong real-time response. By introducing a critical avoidance radius as a hierarchical judgment threshold, when the welding torch is in the outer ring area and has not entered the critical range, the system only performs conventional welding control without needing to perform complex trigonometric function calculations. Only when the radial position enters the critical avoidance radius is a refined avoidance angle calculation initiated. Simultaneously, the system pre-calculates all start and stop arc angles for the current revolution and generates a lookup table. During welding, control actions are triggered simply by real-time angle comparison, effectively reducing the computational load on the programmable logic controller and improving the real-time performance and operational stability of the control response. Attached Figure Description

[0010] Figure 1 This is a schematic diagram of a method flow proposed in an embodiment of this application.

[0011] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0012] It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0013] This invention provides an automatic obstacle avoidance control method for workpiece surfacing welding. This method is applied to a ring-shaped workpiece surfacing welding device, which mainly consists of a programmable logic controller (PLC), a human-machine interface (HMI), a turntable axis, a radial axis, a vertical lifting axis, a welding power source, and a welding torch mechanism. The turntable axis carries the workpiece to be processed and drives it to rotate, forming the main motion mechanism for ring surfacing welding. The radial axis drives the welding torch to move precisely along the radial direction of the workpiece, achieving radial feed operations with different numbers of surfacing revolutions. The vertical lifting axis drives the welding torch to rise and fall perpendicular to the workpiece surface, precisely adjusting the distance between the welding torch and the workpiece surface. The PLC is the core control unit of the device, responsible for parameter storage, position signal acquisition, mathematical logic operations, and control signal output. The HMI is used for manual parameter input, mode selection, and real-time display of welding status. The welding power source receives control commands, precisely executes arc initiation and arc cessation operations, and provides welding current for the surfacing operation. This invention achieves fully automatic and precise avoidance of rectangular weld-free areas during the welding process of annular workpieces through precise geometric calculations and closed-loop linkage control. It also supports two operation modes: conventional corner welding and center welding, and is suitable for batch processing of meniscus-type workpieces.

[0014] like Figure 1 As shown, the present invention provides a workpiece welding control method with automatic obstacle avoidance, comprising the following steps: S1: Obtain workpiece parameters and welding process parameters; The workpiece parameters include the outer radius R of the workpiece, the radial side length a and the tangential side length b of the rectangular weld-free area, and the welding process parameters include the weld overlay starting radius. weld termination radius Radial feed rate and angle compensation value .

[0015] In this embodiment, the workpiece parameters are the core parameters characterizing the geometric dimensions of the ring-shaped workpiece to be processed. Specifically, the outer radius R of the workpiece is the maximum radius value of the outer contour of the ring-shaped workpiece; the rectangular weld-free area is the rectangular empty area at the center of the workpiece that does not require welding; the radial side length 'a' of the rectangular weld-free area is the side length of the rectangular area parallel to the radial axis of movement; and the tangential side length 'b' of the rectangular weld-free area is the side length of the rectangular area parallel to the tangent of the turntable axis rotation and perpendicular to the radial axis of movement. The welding process parameters are key parameters determining the welding trajectory, processing accuracy, and welding quality, including the welding start radius. The radial radius of the workpiece corresponding to the initial position of the welding process, and the welding termination radius. The radial radius of the workpiece corresponding to the termination position of the welding process, and the radial feed rate. The angle compensation value is the fixed distance the welding torch moves radially along the workpiece after each complete weld bead revolution. The positive angle offset, pre-calibrated based on actual process factors such as the welding arc's range of action, servo system response delay, and welding torch motion inertia, is used to correct the theoretical start and stop arc angles and adapt to actual welding conditions.

[0016] The step S1 of obtaining workpiece parameters and welding process parameters specifically includes the following steps: S11: Receive the first set of input parameters through the human-machine interface. The first set of parameters includes the outer radius R of the workpiece, the side length a along the radial direction of the rectangular solderless area and the side length b along the tangential direction, and store the first set of parameters in the data storage area of ​​the programmable logic controller.

[0017] In this embodiment, the human-machine interface adopts an industrial touch screen display, allowing operators to manually input all geometric parameters of the workpiece to be processed. After the parameters are input and confirmed, the human-machine interface transmits the first parameter set to the programmable logic controller (PLC) in real time via the industrial Ethernet communication protocol. The PLC writes this set of parameters into its internal power-off retention data storage area, ensuring that the parameters are not lost after the equipment is powered off and can be directly used for subsequent geometric calculations, logical judgments, and control processes.

[0018] S12: Receive a second set of input parameters through the human-machine interface, the second set of parameters including the weld overlay initiation radius. weld termination radius Radial feed rate Rotary speed v and angle compensation value of the turntable shaft The second parameter set is stored in the data storage area of ​​the programmable logic controller, wherein the weld overlay starting radius is... Smaller than the weld termination radius The radial feed rate It is a positive value.

[0019] In this embodiment, the welding operation of the present invention adopts a radial feed processing method from the inside to the outside, therefore the starting radius of the welding is... The radius of the weld termination point near the center of the workpiece Near the outer edge of the workpiece, ensure that the weld overlay layer is stacked layer by layer from the inside out. Radial feed rate. Setting it to a positive value restricts the radial axis to feed only towards the outer diameter of the workpiece, preventing machining failures caused by incorrect feed direction. The rotary axis rotation speed *v* is the angular velocity at which the rotary axis drives the workpiece to rotate at a constant speed, directly determining the processing rate and weld formation effect of the welding operation. After the operator inputs and confirms the second parameter set, the parameters are synchronously transmitted and stored in the data storage area of ​​the programmable logic controller, and used in conjunction with the first parameter set.

[0020] S13: Read the first parameter set and the second parameter set from the data storage area of ​​the programmable logic controller, and perform a validity check on the first parameter set and the second parameter set. The validity check includes: determining whether the outer radius R of the workpiece is greater than the critical avoidance radius. Determine the starting radius of the weld overlay. Is it greater than or equal to the critical avoidance radius? And determine the radial feed amount Is it greater than 0 and less than the weld termination radius? With the aforementioned weld overlay starting radius difference.

[0021] In this embodiment, parameter validity verification is a pre-test logic implemented before the equipment starts processing. This effectively avoids equipment idling, mis-welding, mechanical interference, and other malfunctions caused by manual parameter input errors or abnormal parameter matching, ensuring processing stability. Specifically, the workpiece outer radius R is greater than the critical clearance radius. This ensures that the rectangular weld-free area is completely contained within the outer contour of the workpiece, preventing the weld-free area from exceeding the workpiece's machining range; the starting radius of the weld overlay... Greater than or equal to the critical avoidance radius This ensures that the first weld bead position is outside the circumcircle of the rectangular weld-free area, allowing the first weld bead to be completed continuously without needing to activate avoidance logic; radial feed rate Greater than 0 and less than the weld termination radius With weld overlay starting radius The difference ensures that the feed direction is compliant and the feed step size is reasonable, enabling all welding operations to be completed within the set radial range without blind spots or overtravel risks. If the parameter verification fails, the programmable logic controller immediately pushes a parameter anomaly prompt to the human-machine interface, locks the machining program, and the welding operation can only be started after the operator corrects the parameters and completes a second verification.

[0022] S2: Establish a coordinate system with the workpiece center as the origin, calibrate the zero point position of the turntable axis and the zero point position of the radial axis, and calculate the circumcircle radius of the rectangular solderless area as the critical avoidance radius based on the side length of the rectangular solderless area in the radial direction and the side length in the tangential direction.

[0023] In this embodiment, a unified coordinate system serves as the benchmark for all subsequent position acquisition, angle calculation, and arc start / stop control, enabling precise correlation between workpiece geometric parameters, axis motion positions, and welding control logic. Dual-axis zero-point calibration provides a unified physical reference benchmark for servo motion, ensuring a one-to-one correspondence between the axis positions and angle values ​​read by the programmable logic controller and the actual physical positions of the workpiece, guaranteeing avoidance control accuracy from the outset. The critical avoidance radius is the core trigger threshold for the automatic avoidance logic, used for graded adjustment of the control logic. Rectangular weld-free area avoidance calculations and control are initiated only when the radial position of the welding torch enters this radius range. The outer ring welding requires no complex calculations, balancing processing accuracy and control efficiency.

[0024] Step S2, which involves establishing a coordinate system with the workpiece center as the origin and calibrating the zero point, specifically includes the following steps: S21: Establish a planar polar coordinate system with the workpiece center as the origin, the welding torch radial movement direction as the positive X-axis, and the turntable rotation direction as the T-axis. The geometric center of the rectangular weld-free area coincides with the origin, and each side of the rectangular weld-free area is parallel to or perpendicular to the X-axis.

[0025] In this embodiment, the establishment of the planar polar coordinate system is highly compatible with the device motion pattern of rotary table axis rotation and radial axis linear feed, which simplifies the calculation logic of polar radius and polar angle. The layout design, in which the geometric center of the rectangular solderless area coincides with the coordinate origin and each side is parallel or perpendicular to the coordinate axis, can make full use of the geometric symmetry of the rectangle, greatly reduce the amount of trigonometric function calculation, reduce the computational load of the programmable logic controller, and improve the control response speed.

[0026] S22: Send a first origin return command to the first servo driver of the turntable axis to control the turntable axis to rotate to the first preset origin position. The first preset origin position is the intersection of the vertical bisector of any side of the rectangular solderless area and the solder surfacing trajectory. When the turntable axis reaches the first preset origin position, clear the first counter of the programmable logic controller to complete the zero-point calibration of the turntable axis.

[0027] In this embodiment, the first servo driver is a dedicated drive control unit for the turntable axis, communicating with the programmable logic controller (PLC) via an industrial bus. It can accurately receive and execute motion commands. After the origin return command is triggered, the turntable axis rotates smoothly at a preset low speed, precisely stopping at the first preset origin position in conjunction with the equipment positioning structure. Selecting the perpendicular bisector of the edge of the rectangular solderless area as the zero-point reference ensures that the two opposite sides of the rectangle are symmetrically distributed relative to the zero point. Subsequent angle thresholds and start / stop arc angles can be quickly derived through this symmetry, simplifying the calculation process. The first counter inside the PLC records the turntable axis rotation angle in real time. After the zero point is cleared, the real-time counter value is the actual rotation angle of the turntable axis relative to the reference zero point.

[0028] S23: Send a second origin return command to the second servo driver of the radial axis to control the radial axis to move to the second preset origin position, the second preset origin position being the radial position corresponding to the coordinate origin, and when the radial axis reaches the second preset origin position, clear the second counter of the programmable logic controller to complete the radial axis zero point calibration.

[0029] In this embodiment, the second servo driver is a dedicated drive control unit for the radial axis, which can precisely control the linear displacement of the radial axis. The second preset origin position corresponds to the radial zero position of the workpiece center, representing the initial radial reference position of the welding torch. After the radial axis completes the origin return and the second counter is cleared, the real-time value of the counter is the radial distance from the current position of the welding torch to the center of the workpiece, which is the current position of the radial axis, providing accurate data support for subsequent radial position judgment and angle calculation.

[0030] S24: Based on the radial and tangential side lengths of the rectangular solderless area, calculate the circumcircle radius of the rectangular solderless area as the critical clearance radius. The specific calculation method is as follows: square half of the radial side length and half of the tangential side length of the rectangular solderless area respectively, sum them, and then perform a square root operation on the sum.

[0031] The formula for calculating the critical avoidance radius is as follows: ; Where a is the radial side length of the rectangular solderless area, and b is the tangential side length of the rectangular solderless area. The critical avoidance radius.

[0032] In this embodiment, the critical avoidance radius is physically defined as the maximum distance from the four vertices of the rectangular weld-free area to the origin of the coordinate system, i.e., the radius of the circumcircle of the rectangle. When the current position of the radial axis is greater than the critical avoidance radius, the welding torch's circular welding trajectory completely leaves the rectangular weld-free area, with no risk of interference, and continuous welding can be performed without avoidance. When the current position of the radial axis is less than or equal to the critical avoidance radius, the welding torch trajectory intersects with the rectangular weld-free area, and the automatic avoidance logic must be activated to complete the weld-free operation through precise arc start and stop.

[0033] S3: Calculate the angle threshold of each vertex of the rectangular solderless area relative to the origin of the coordinate system based on the side length of the rectangular solderless area in the radial direction and the side length in the tangential direction, and obtain the current position of the radial axis and the current angle of the turntable axis in real time during the welding process.

[0034] In this embodiment, the angle thresholds corresponding to the four vertices serve as the boundary benchmarks for the angle intervals of the four sides of the rectangle. This divides the 360° rotation range of the turntable axis into four independent angle intervals, each corresponding to one of the four sides of the rectangular weld-free area. This is the core basis for determining the real-time orientation of the welding torch and matching the corresponding start and stop arc angles. During the welding process, the axis position and angle data are collected in real time to form a closed-loop real-time control, ensuring that the avoidance logic for each round of welding is accurately adapted to the real-time working conditions.

[0035] Step S3, which calculates the angle thresholds of each vertex of the rectangular solderless area relative to the origin of the coordinate system, specifically includes the following steps: S31: Based on the side lengths of the rectangular solderless area along the radial direction and the tangential direction, calculate the first angle threshold of the first vertex of the rectangular solderless area relative to the positive X-axis direction. Specifically, the calculation method is as follows: divide the side length along the tangential direction by the side length along the radial direction to obtain a first ratio, and then perform an arctangent operation on the first ratio to obtain the first angle threshold.

[0036] The formula for calculating the first angle threshold is as follows: ; Where a is the radial side length of the rectangular solderless area, and b is the tangential side length of the rectangular solderless area. This is the first angle threshold.

[0037] In this embodiment, the first vertex is the upper right corner vertex of the first quadrant of the rectangular solderless area. The radial and tangential coordinates of this vertex correspond to half the length of the rectangle, respectively. The angle between this vertex and the positive X-axis can be accurately calculated using the arctangent function. This angle is the dividing point between the right and top sides of the rectangle.

[0038] S32: Based on the first angle threshold, and utilizing the geometric symmetry of the rectangular solderless area, calculate the second angle threshold of the second vertex relative to the positive X-axis, the third angle threshold of the third vertex relative to the positive X-axis, and the fourth angle threshold of the fourth vertex relative to the positive X-axis, respectively. The second angle threshold is equal to π minus the first angle threshold, the third angle threshold is equal to π plus the first angle threshold, and the fourth angle threshold is equal to 2π minus the first angle threshold.

[0039] The formulas for calculating the angle thresholds for each vertex are as follows: ; ; ; in, The second angle threshold, The third angle threshold, This is the threshold for the fourth angle.

[0040] In this embodiment, the second vertex is the top-left vertex of the second quadrant of the rectangle, the third vertex is the bottom-left vertex of the third quadrant of the rectangle, and the fourth vertex is the bottom-right vertex of the fourth quadrant of the rectangle. Based on the geometric characteristics of the rectangle's central and axial symmetry, only a single arctangent operation is needed to obtain the first angle threshold, which can quickly derive the angles of the other three vertices without repeating complex calculations, thus greatly improving the program's running efficiency.

[0041] S33: Store the first angle threshold, the second angle threshold, the third angle threshold, and the fourth angle threshold in the data storage area of ​​the programmable logic controller as the angle interval boundary value of the rectangular side region to which the current angle of the turntable axis belongs.

[0042] In this embodiment, four angle thresholds divide the complete angle range of 0~2π into four independent segments, corresponding to the right, top, left, and bottom edges of the rectangular solderless area, respectively. The programmable logic controller (PLC) stores the angle thresholds in a fixed format and directly calls them for comparison during the soldering process, eliminating the need for real-time calculations and improving control real-time performance.

[0043] S34: During the welding process, the current angle of the turntable axis is read in real time by the first counter of the programmable logic controller, and the current position of the radial axis is read in real time by the second counter of the programmable logic controller. The current angle of the turntable axis is compared with the first angle threshold, the second angle threshold, the third angle threshold and the fourth angle threshold to determine the rectangular side area to which the current angle of the turntable axis belongs.

[0044] In this embodiment, the programmable logic controller continuously collects axis parameters and completes interval comparison with a millisecond-level control cycle, accurately determining the rectangular side that the welding torch is currently facing, providing a precise basis for subsequent targeted calculation of the start and stop arc angles of the corresponding side, and eliminating the avoidance failure problem caused by mismatch of angle intervals.

[0045] S4: When it is determined that the current position of the radial axis is less than or equal to the critical avoidance radius, the actual arc-stopping angle and the actual arc-starting angle corresponding to each side of the rectangle under the current number of welding circles are calculated based on the current position of the radial axis, the current angle of the turntable axis, the side length of the rectangular solderless area along the radial direction, the side length of the rectangular solderless area along the tangential direction, and the angle compensation value.

[0046] In this embodiment, the refined angle calculation logic is activated only when the radial position of the welding torch enters the critical avoidance radius range. Based on the real-time radial position dynamic matching trigonometric function model, the theoretical start and stop arc angles of the four sides of the rectangle are calculated respectively, and then the process angle compensation value is superimposed to correct the process errors caused by servo response delay and arc diffusion. This ensures that the boundary of the weld-free area is regular and the welding area is continuous and defect-free under different radial processing positions, completely avoiding the problems of over-welding and missed welding.

[0047] In step S4, the arc-stopping angle and arc-starting angle corresponding to each side of the rectangle under the current number of weld overlays are calculated based on the current position of the radial axis. For the right side of the rectangular weld-free area, the specific steps include: S411: When it is determined that the current position of the radial axis is less than or equal to the critical avoidance radius and the current angle of the turntable axis is within the angle range corresponding to the right of the rectangular solderless area, the current position of the radial axis is obtained as the current radial distance.

[0048] In this embodiment, the right side of the rectangular solderless area corresponds to the angle range from the fourth angle threshold to the first angle threshold. The system only performs angle calculation on the corresponding side when both position and angle conditions match, avoiding invalid calculations and improving program efficiency. The current radial distance is the trajectory radius of the current weld bead ring and is the core variable for angle calculation.

[0049] S412: Based on the current radial distance and the side length of the rectangular solderless area along the radial direction, calculate the first theoretical arc-stopping angle corresponding to the right side of the rectangular solderless area. Specifically, the calculation method is as follows: divide half of the side length along the radial direction by the current radial distance to obtain a second ratio, and then perform an inverse cosine operation on the second ratio to obtain the first theoretical arc-stopping angle.

[0050] The formula for calculating the first theoretical stopping angle is as follows: ; in, is the current position of the radial axis, and 'a' is the side length of the rectangular solderless area along the radial direction. This is the first theoretical stopping angle.

[0051] In this embodiment, the formula is derived based on the geometric principle of right triangles. The intersection of the welding trajectory circle with the workpiece origin as the center and the current radial distance as the radius and the right side of the rectangle is the critical point for welding avoidance. The critical angle for the welding gun to enter the weld-free area is accurately solved by the inverse cosine function.

[0052] S413: Based on the first theoretical arc-stopping angle, determine the first theoretical arc-starting angle corresponding to the right side of the rectangular solderless area, wherein the first theoretical arc-starting angle is the opposite of the first theoretical arc-stopping angle.

[0053] In this embodiment, based on the geometric characteristic that the right side of the rectangle is symmetrical about the X-axis, the absolute value of the arc starting angle when the welding torch leaves the solderless area is equal to the absolute value of the arc stopping angle when it enters the solderless area, but with opposite signs, which simplifies the logic for solving the corresponding angle.

[0054] S414: Obtain the angle compensation value, subtract the angle compensation value from the first theoretical arc-stopping angle to obtain the first actual arc-stopping angle, and add the angle compensation value to the first theoretical arc-starting angle to obtain the first actual arc-starting angle, wherein the angle compensation value is a positive angle offset preset according to the welding process.

[0055] The actual start-stop arc angle calculation formula is as follows: ; ; in, This is the angle compensation value. This is the first actual stopping angle. This is the first actual arc initiation angle.

[0056] In this embodiment, the angle compensation value is used to adapt to the actual welding conditions, stop the arc in advance, delay the arc start, reserve a process safety margin, avoid boundary overflow caused by arc diffusion and equipment response delay, and ensure that the weld-free area is clean and free of solder residue.

[0057] Further, in step S4, the arc-stopping angle and arc-starting angle corresponding to each side of the rectangle for the current number of weld overlays are calculated based on the current position of the radial axis. For the left, top, and bottom sides of the rectangular weld-free area, the specific steps include: S421: For the left side of the rectangular solderless area, obtain the current position of the radial axis as the current radial distance. Based on the current radial distance and the side length of the rectangular solderless area along the radial direction, calculate the second theoretical arc-stopping angle and the second theoretical arc-starting angle corresponding to the left side of the rectangular solderless area. The specific calculation method is as follows: divide half of the side length along the radial direction by the current radial distance to obtain a third ratio. Perform an inverse cosine operation on the third ratio to obtain a first intermediate angle. The second theoretical arc-stopping angle is equal to π plus the first intermediate angle. The second theoretical arc-starting angle is equal to π minus the first intermediate angle. Subtract the angle compensation value from the second theoretical arc-stopping angle to obtain the second actual arc-stopping angle. Add the angle compensation value to the second theoretical arc-starting angle to obtain the second actual arc-starting angle.

[0058] The formula for calculating the start-stop arc angle on the left is as follows: ; ; ; ; in, This is the second theoretical stopping angle. This is the starting angle of the second theory. This is the second actual stopping angle. This is the second actual arc initiation angle.

[0059] In this embodiment, the left side of the rectangle is located on the negative X-axis side. The critical position is solved by combining the π angle with the middle angle. The compensation logic is completely consistent with that on the right side, ensuring the uniformity of the four-sided avoidance process.

[0060] S422: For the upper edge of the rectangular solderless area, obtain the current position of the radial axis as the current radial distance. Based on the current radial distance and the side length of the rectangular solderless area along the tangential direction, calculate the third theoretical arc-stopping angle and the third theoretical arc-starting angle corresponding to the upper edge of the rectangular solderless area. The specific calculation method is as follows: divide half of the side length along the tangential direction by the current radial distance to obtain a fourth ratio. Perform an arcsine operation on the fourth ratio to obtain a second intermediate angle. The third theoretical arc-stopping angle is equal to the second intermediate angle. The third theoretical arc-starting angle is equal to the opposite of the second intermediate angle. Subtract the angle compensation value from the third theoretical arc-stopping angle to obtain the third actual arc-stopping angle. Add the angle compensation value to the third theoretical arc-starting angle to obtain the third actual arc-starting angle.

[0061] The formula for calculating the start and stop arc angle is as follows: ; ; ; ; in, This is the third theoretical stopping angle. The starting angle of the arc in the third theory, This is the third actual stopping angle. This is the third actual arc initiation angle.

[0062] In this embodiment, the upper edge of the rectangle is arranged along the tangential direction, and the critical angle is solved using the arcsine function to adapt to the geometric layout characteristics of the upper edge and ensure the accuracy of the angle calculation.

[0063] S423: For the lower edge of the rectangular solderless area, obtain the current position of the radial axis as the current radial distance. Based on the current radial distance and the side length of the rectangular solderless area along the tangential direction, calculate the fourth theoretical arc-stopping angle and the fourth theoretical arc-starting angle corresponding to the lower edge of the rectangular solderless area. The specific calculation method is as follows: divide half of the side length along the tangential direction by the current radial distance to obtain a fifth ratio. Perform an arcsine operation on the fifth ratio to obtain a third intermediate angle. The fourth theoretical arc-stopping angle is equal to π minus the third intermediate angle. The fourth theoretical arc-starting angle is equal to π plus the third intermediate angle. Subtract the angle compensation value from the fourth theoretical arc-stopping angle to obtain the fourth actual arc-stopping angle. Add the angle compensation value to the fourth theoretical arc-starting angle to obtain the fourth actual arc-starting angle.

[0064] The formula for calculating the start and stop arc angle is as follows: ; ; ; ; in, This is the fourth theoretical stopping angle. For the fourth theory of arc starting angle, This is the fourth actual stopping angle. This is the fourth actual arc initiation angle.

[0065] In this embodiment, the calculation of the lower angle is derived based on the principle of symmetry of the upper side, and the angle compensation rules are unified, so as to achieve full coverage and high-precision matching of the rectangular four-sided avoidance logic.

[0066] S424: Store the first actual arc-stopping angle, the second actual arc-stopping angle, the third actual arc-stopping angle, the fourth actual arc-stopping angle, the first actual arc-starting angle, the second actual arc-starting angle, the third actual arc-starting angle, and the fourth actual arc-starting angle in the data storage area of ​​the programmable logic controller, as an arc-stopping angle lookup table and an arc-starting angle lookup table for the current number of welding circles.

[0067] In this embodiment, all start and stop arc angles are pre-calculated and a lookup table is generated before each round of welding. During the welding process, only angle comparison is required, without real-time calculation, which greatly reduces the computing pressure on the controller, improves the response speed and accuracy of start and stop arc actions, and ensures welding continuity.

[0068] S5: Based on the actual arc-stopping angle and the actual arc-starting angle, when the current angle of the turntable shaft reaches the actual arc-stopping angle, output an arc-stopping control signal to the welding power source to stop the welding process, and when the current angle of the turntable shaft reaches the actual arc-starting angle, output an arc-starting control signal to the welding power source to restart the arc.

[0069] In this embodiment, this step is the core execution link of automatic obstacle avoidance. The arc start and stop actions are precisely triggered by real-time angle comparison, and the vertical lifting axis is linked to complete the lifting and lowering of the welding torch. This realizes fully automatic closed-loop control of arc stop lifting to avoid obstacles and arc start and torch lowering for welding. This ensures that there is no wrong welding in the non-welding area and prevents the welding torch from running idle and scraping the workpiece, thus ensuring equipment safety and welding quality.

[0070] Step S5 involves performing arc-stopping control and arc-starting control based on the actual arc-stopping angle and the actual arc-starting angle, specifically including the following steps: S51: During the welding process, the current angle of the turntable shaft is obtained in real time through the first counter of the programmable logic controller, and the current angle of the turntable shaft is compared with the actual arc-stopping angle corresponding to the current number of welding circles.

[0071] In this embodiment, the programmable logic controller continuously and at high speed collects turntable axis angle data, matches the arc-stopping angle threshold of the current revolution in real time, dynamically monitors the welding trajectory throughout the process, and predicts the avoidance opportunity in advance.

[0072] S52: When it is determined that the current angle of the turntable axis is greater than or equal to the actual arc-stopping angle, the programmable logic controller outputs an arc-stopping control signal to the first control port of the welding power supply to control the welding power supply to cut off the welding current to stop the welding. At the same time, the programmable logic controller sends a first lifting command to the third servo driver of the vertical lifting axis to control the welding torch to be raised from the welding height to the preset safe height.

[0073] In this embodiment, the arc-stop signal and the torch-lifting action are executed synchronously, shortening the response delay. The safety height is a preset fixed value, higher than the maximum weld overlay height of the workpiece, ensuring that there is no mechanical interference when the welding torch crosses the weld-free area.

[0074] S53: When the welding torch is at the safe height, the programmable logic controller controls the turntable shaft to continue rotating, and obtains the current angle of the turntable shaft in real time through the first counter, and compares the current angle of the turntable shaft with the actual arc starting angle corresponding to the current number of welding circles.

[0075] In this embodiment, the turntable shaft maintains a constant speed during the avoidance process, eliminating the need to stop and decelerate, thus ensuring a continuous and stable welding cycle and improving overall processing efficiency.

[0076] S54: When it is determined that the current angle of the turntable axis is greater than or equal to the actual arc-starting angle, the programmable logic controller sends a second lifting command to the third servo driver of the vertical lifting axis to control the welding torch to descend from the safe height to the welding height, and after the welding torch reaches the welding height, it outputs an arc-starting control signal to the second control port of the welding power supply to control the welding power supply to turn on the welding current to restart the arc.

[0077] In this embodiment, a timing logic of first lowering the welding torch and then starting the arc is adopted to ensure that welding is started only after the welding torch is in place, thereby eliminating arc instability and weld formation defects caused by suspended arc starting, and improving the arc starting success rate and welding quality.

[0078] S55: After the arc is restarted, the programmable logic controller continues to perform real-time angle tracking and judgment during the welding process until the current number of weld overlays is completed.

[0079] In this embodiment, the avoidance actions of the four sides of the rectangle are completed sequentially during the single-circle welding process. The entire process is fully automatic closed-loop control without manual intervention until the turntable shaft completes a full circle of rotation, at which point the current circle of welding operation ends.

[0080] S6: When it is detected that the turntable shaft has completed a full rotation, control the radial axis to perform a radial feed according to the radial feed amount, and repeat steps S3 to S6 until the current position of the radial axis reaches the welding termination radius.

[0081] In this embodiment, this step realizes the cyclic control of multi-turn layer-by-layer welding. Radial full-coverage welding is achieved by radial feeding in turn, and the avoidance angle parameters are dynamically updated in each turn to adapt to the geometric features of different radial positions, ensuring consistent avoidance accuracy and uniform and regular weld layer throughout the entire processing range.

[0082] Step S6, which involves controlling the radial axis to perform a radial feed once according to the radial feed amount and repeating the process, specifically includes the following steps: S61: The rotation angle of the turntable shaft is monitored in real time by the first counter of the programmable logic controller. When the cumulative rotation angle of the turntable shaft reaches 360°, it is determined that the current number of welding turns is completed, and a turn completion interrupt signal is generated.

[0083] In this embodiment, the interrupt signal is used to determine the completion of the number of revolutions. This method has a fast response speed, no program scanning delay, and accurately locks the end node of each revolution of welding, ensuring that the feeding timing is accurate.

[0084] S62: In response to the completion interrupt signal of the number of revolutions, the programmable logic controller reads the current position of the radial axis and compares the current position of the radial axis with the weld overlay termination radius.

[0085] In this embodiment, after each round of processing is completed, a termination condition judgment is performed first to accurately determine whether all welding operations have been completed, thereby achieving automatic start-stop control.

[0086] S63: If the current position of the radial axis is less than the weld termination radius, the programmable logic controller sends a radial feed command to the second servo driver of the radial axis, controls the radial axis to move the radial feed amount in the radial direction to reach a new radial position, and updates the count value of the second counter of the programmable logic controller.

[0087] In this embodiment, the radial outward feeding method matches the inside-out welding process. The fixed feed amount ensures that the weld overlay layer overlaps evenly, without welding gaps or excessive weld overlay.

[0088] S64: After the radial axis completes the radial feed movement, the programmable logic controller increments the weld overlay count counter by 1, and recalculates the actual arc stop angle and actual arc start angle corresponding to each side of the rectangular weld-free area according to the new radial position, so as to update the arc stop angle lookup table and the arc start angle lookup table.

[0089] In this embodiment, after the radial position changes, the radius of the weld overlay trajectory changes synchronously, and the critical avoidance angle of the weld-free area changes accordingly. The angle lookup table is updated in real time to ensure that the avoidance logic of the next circle is accurately adapted to the new processing conditions.

[0090] S65: Repeat steps S3 to S6, and perform the next round of welding under the updated actual arc-stopping angle and actual arc-starting angle until the current position of the radial axis is greater than or equal to the welding termination radius. Then, the programmable logic controller outputs a welding end signal to the welding power supply, controls the welding power supply to cut off the welding current, and sends a reset command to each servo driver.

[0091] In this embodiment, the system automatically completes the welding operation in the entire range in a fully cyclical manner. After the processing is completed, the power is automatically cut off and the shaft is reset, returning the equipment to the standby state, thus realizing unattended automated processing.

[0092] S7: Center Welding Mode Operation Procedure The method of this invention also includes a center-mounted welding mode, which can adapt to the single-sided crescent-shaped welding requirements of meniscus-like workpieces. Based on the core geometric calculation framework, mode switching can be achieved simply by interchangeing the start and stop arc angle logic, without the need to modify hardware equipment, thus greatly expanding the scope of process applicability. Specifically, it includes the following steps: S71: Receive a mode selection instruction through the human-machine interface. When the mode selection instruction indicates the center welding mode, the programmable logic controller swaps the theoretical arc-stopping angle and the theoretical arc-starting angle corresponding to the target side in the rectangular solderless area, and superimposes the swapped angle with the angle compensation value to obtain the actual arc-starting angle and the actual arc-stopping angle under the center welding mode.

[0093] In this embodiment, the operator can select any side of the rectangle as the target welding boundary as needed. By exchanging the angle logic, the original welding avoidance start and stop logic is converted into fixed-side half-ring welding logic. The angle compensation rules are completely consistent with the conventional mode, ensuring process stability.

[0094] S72: In the center welding mode, the angle corresponding to one end point of the target side of the rectangular weld-free area is used as the center welding arc starting angle, and the angle corresponding to the other end point of the target side is used as the center welding arc stopping angle. The welding gun is controlled to start the arc from one side of the target side and weld along the circular trajectory to stop the arc on the other side of the target side, so as to form a crescent-shaped welding layer on one side of the rectangular weld-free area.

[0095] In this embodiment, the center welding mode forms a continuous semi-circular welding layer only on one side of the target edge. The boundary is precisely aligned with the rectangular weld-free area, and the welding layer has high regularity, perfectly meeting the forming requirements of the meniscus workpiece.

[0096] S73: After each crescent-shaped weld overlay is completed, the programmable logic controller controls the radial axis to perform a radial feed according to the radial feed amount, and repeats the arc initiation, weld overlay and arc cessation operations of the center weld overlay mode at the new radial position until the current position of the radial axis reaches the weld overlay termination radius.

[0097] In this embodiment, the radial feed, angle update, and loop control logic of the center welding mode are consistent with those of the conventional corner welding mode. By layering crescent-shaped welding layers, the single-sided full radial interval welding process is completed.

[0098] Overall technical advantages of the invention This invention, by establishing a standardized polar coordinate calculation model, a hierarchical avoidance judgment mechanism, and dual-mode welding logic, completely solves the industry pain points of existing ring-shaped workpiece cladding processes, such as the inability to accurately avoid rectangular weld-free areas, excessive manual intervention, poor processing consistency, material waste, and high secondary processing costs. The entire process is fully automated and controlled by a programmable logic controller (PLC), eliminating the need for real-time manual adjustment of arc start / stop actions, significantly reducing labor costs and improving processing efficiency. All avoidance positions and welding trajectories are precisely calculated using mathematical formulas, eliminating human judgment errors. The cladding boundaries are neat, without overflow or incomplete welding defects, requiring no subsequent grinding or repair. It is compatible with both conventional corner cladding and center crescent-shaped cladding processes, adapting to the mass production needs of most crescent-shaped workpieces. The process boasts strong versatility, a high degree of automation, and significantly superior processing accuracy and stability compared to traditional manual and semi-automatic cladding processes.

[0099] This invention also discloses an automatic obstacle avoidance workpiece welding control system, comprising: The acquisition module is used to acquire workpiece parameters and welding process parameters. The workpiece parameters include the outer radius of the workpiece, the side length of the rectangular weld-free area in the radial direction and the side length in the tangential direction. The welding process parameters include the weld overlay start radius, weld overlay end radius, radial feed amount and angle compensation value. The module is used to establish a coordinate system with the workpiece center as the origin, calibrate the zero point position of the turntable axis and the radial axis, and calculate the critical avoidance radius based on the side length of the rectangular weld-free area in the radial direction and the side length in the tangential direction. The calculation module is used to calculate the angle threshold of each vertex of the rectangular solderless area relative to the origin of the coordinate system based on the side length of the rectangular solderless area in the radial direction and the side length in the tangential direction, and to obtain the current position of the radial axis and the current angle of the turntable axis in real time during the welding process. The judgment module is used to calculate the actual arc-stopping angle and actual arc-starting angle of each side of the rectangle under the current number of welding circles when the current position of the radial axis is determined to be less than or equal to the critical avoidance radius, based on the current position of the radial axis, the side length of the rectangular solderless area along the radial direction, the side length of the rectangular solderless area along the tangential direction, and the angle compensation value. The processing module is used to perform an arc-stopping operation when the current angle of the turntable axis reaches the actual arc-stopping angle, and to perform an arc-starting operation when the current angle of the turntable axis reaches the actual arc-starting angle, based on the actual arc-stopping angle and the actual arc-starting angle. The control module is used to control the radial axis to perform a radial feed according to the radial feed amount when it is detected that the turntable axis has completed a full rotation, and repeat the above steps until the current position of the radial axis reaches the welding termination radius.

[0100] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes of the embodiments of the above methods. Any references to memory, storage, databases, or other media used in this application and in the embodiments can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in a variety of forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), dual data rate SDRAM (SSRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), RAMbus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).

[0101] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, apparatus, article, or method that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, apparatus, article, or method. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, apparatus, article, or method that includes that element.

[0102] The above description is merely a preferred embodiment of the present invention and does not limit the scope of this application. Any equivalent results or equivalent process transformations made based on the content of the present invention's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the scope of protection of this application.

Claims

1. A method for controlling workpiece welding with automatic obstacle avoidance, characterized in that, Includes the following steps: Obtain workpiece parameters and welding process parameters. The workpiece parameters include the outer radius of the workpiece, the side length of the rectangular weld-free area in the radial direction and the side length in the tangential direction. The welding process parameters include the weld overlay start radius, weld overlay end radius, radial feed amount and angle compensation value. Establish a coordinate system with the workpiece center as the origin, calibrate the zero point position of the turntable axis and the zero point position of the radial axis, and calculate the critical avoidance radius based on the side length of the rectangular weld-free area in the radial direction and the side length in the tangential direction. The angle thresholds of each vertex of the rectangular solderless area relative to the origin of the coordinate system are calculated based on the side lengths of the rectangular solderless area in the radial direction and the side lengths in the tangential direction, and the current position of the radial axis and the current angle of the turntable axis are obtained in real time during the welding process. When it is determined that the current position of the radial axis is less than or equal to the critical avoidance radius, the actual arc-stopping angle and the actual arc-starting angle corresponding to each side of the rectangle under the current number of welding circles are calculated based on the current position of the radial axis, the side length of the rectangular solderless area along the radial direction, the side length of the rectangular solderless area along the tangential direction, and the angle compensation value. Based on the actual arc-stopping angle and the actual arc-starting angle, an arc-stopping operation is performed when the current angle of the turntable axis reaches the actual arc-stopping angle, and an arc-starting operation is performed when the current angle of the turntable axis reaches the actual arc-starting angle. When the turntable shaft completes a full rotation, the radial axis is controlled to perform a radial feed according to the radial feed amount, and the above steps are repeated until the current position of the radial axis reaches the welding termination radius.

2. The workpiece welding control method with automatic obstacle avoidance according to claim 1, characterized in that, The acquisition of workpiece parameters and welding process parameters specifically includes: The system receives a first set of parameters through a human-machine interface. The first set of parameters includes the outer radius of the workpiece, the side length of the rectangular weld-free area in the radial direction, and the side length in the tangential direction. The first set of parameters is then stored in the programmable logic controller. The second parameter set is received through the human-machine interface. The second parameter set includes the welding start radius, welding end radius, radial feed, turntable axis rotation speed and angle compensation value. The second parameter set is then stored in the programmable logic controller. The programmable logic controller reads the first parameter set and the second parameter set, and performs validity checks on the first parameter set and the second parameter set. The validity checks include: determining whether the outer radius of the workpiece is greater than the critical clearance radius, determining whether the welding start radius is greater than or equal to the critical clearance radius, and determining whether the radial feed is less than the difference between the welding end radius and the welding start radius.

3. The workpiece welding control method with automatic obstacle avoidance according to claim 1, characterized in that, The calibration of the turntable axis zero point position and radial axis zero point position, and the calculation of the critical clearance radius based on the radial and tangential side lengths of the rectangular solderless area, specifically includes: A planar polar coordinate system is established with the workpiece center as the origin, the radial movement direction of the welding gun as the positive axis, and the rotation direction of the turntable axis as the axial direction. The geometric center of the rectangular solderless area coincides with the origin, and each side of the rectangular solderless area is parallel to or perpendicular to the axial direction. Send a first origin return command to the turntable axis to control the turntable axis to rotate to the first preset origin position, and complete the turntable axis zero point calibration when the turntable axis reaches the first preset origin position; Send a second origin return command to the radial axis to control the radial axis to move to the second preset origin position, and complete the radial axis zero point calibration when the radial axis reaches the second preset origin position; The radius of the circumcircle of the rectangular solderless area is calculated as the critical clearance radius based on the radial and tangential side lengths of the rectangular solderless area.

4. The workpiece welding control method with automatic obstacle avoidance according to claim 1, characterized in that, The calculation of the angle thresholds of each vertex of the rectangular solderless region relative to the origin of the coordinate system specifically includes: Based on the side lengths of the rectangular solderless region in the radial direction and the tangential direction, calculate the first angle threshold of the first vertex of the rectangular solderless region relative to the positive axis direction; Based on the first angle threshold, and utilizing the geometric symmetry of the rectangular solderless region, the second angle threshold of the second vertex relative to the positive axis direction, the third angle threshold of the third vertex relative to the positive axis direction, and the fourth angle threshold of the fourth vertex relative to the positive axis direction are calculated respectively. The first angle threshold, the second angle threshold, the third angle threshold, and the fourth angle threshold are stored in the programmable logic controller as the angle interval boundary values ​​of the rectangular side region to which the current angle of the turntable axis belongs; During the welding process, the programmable logic controller reads the current angle of the turntable axis and the current position of the radial axis in real time, and compares the current angle of the turntable axis with each of the angle thresholds to determine the rectangular side region to which the current angle of the turntable axis belongs.

5. The workpiece welding control method with automatic obstacle avoidance according to claim 1, characterized in that, The calculation of the actual arc-stopping angle and actual arc-starting angle corresponding to each side of the rectangle under the current number of weld overlays specifically includes: When it is determined that the current position of the radial axis is less than or equal to the critical avoidance radius, the current position of the radial axis is obtained as the current radial distance, and the target rectangular side region to which the current angle of the turntable axis belongs is determined. Based on the current radial distance, the orientation of the target rectangular side region, and the side length parameters of the rectangular solderless region corresponding to the target rectangular side region, the theoretical arc-stopping angle corresponding to the target rectangular side region is calculated based on a preset geometric calculation model. Based on the theoretical stopping angle, the theoretical starting angle corresponding to the target rectangular side region is determined based on the geometric symmetry relationship of the target rectangular side region; The angle compensation value is obtained, and the theoretical arc-stopping angle is superimposed with the angle compensation value to obtain the actual arc-stopping angle. The theoretical arc-starting angle is superimposed with the angle compensation value to obtain the actual arc-starting angle.

6. The workpiece welding control method with automatic obstacle avoidance according to claim 5, characterized in that, The calculation of the theoretical stopping angle corresponding to the side region of the target rectangle based on the preset geometric calculation model specifically includes: For the right side of the rectangular solderless area, the theoretical arc-stopping angle corresponding to the right side is calculated based on the current radial distance and the side length of the rectangular solderless area in the radial direction, according to the side-angle relationship of a right triangle, and the theoretical arc-starting angle corresponding to the right side is determined according to the opposite of the theoretical arc-stopping angle. For the left side of the rectangular solderless area, based on the current radial distance and the side length of the rectangular solderless area in the radial direction, the theoretical arc-stopping angle and theoretical arc-starting angle corresponding to the left side are calculated based on the side-angle relationship of a right triangle and combined with the calculation of pi. For the upper edge of the rectangular solderless area, the theoretical arc-stopping angle and theoretical arc-starting angle corresponding to the upper edge are calculated based on the current radial distance and the side length of the rectangular solderless area along the tangential direction, according to the side-angle relationship of a right triangle. For the lower edge of the rectangular solderless area, based on the current radial distance and the side length of the rectangular solderless area along the tangential direction, the theoretical arc-stopping angle and theoretical arc-starting angle corresponding to the lower edge are calculated based on the side-angle relationship of a right triangle and combined with the calculation of pi.

7. The workpiece welding control method with automatic obstacle avoidance according to claim 1, characterized in that, The step of performing an arc-stopping operation when the current angle of the turntable axis reaches the actual arc-stopping angle, and performing an arc-initiating operation when the current angle of the turntable axis reaches the actual arc-initiating angle, specifically includes: During the welding process, the programmable logic controller acquires the current angle of the turntable axis in real time and compares the current angle of the turntable axis with the actual arc-stopping angle corresponding to the current number of welding circles. When it is determined that the current angle of the turntable axis is greater than or equal to the actual arc-stopping angle, the programmable logic controller controls the welding power supply to stop welding and simultaneously controls the welding torch to rise from the welding height to a preset safe height. When the welding torch is at the safe height, the programmable logic controller controls the turntable shaft to continue rotating and acquires the current angle of the turntable shaft in real time, and compares the current angle of the turntable shaft with the actual arc starting angle corresponding to the current number of welding circles. When it is determined that the current angle of the turntable axis is greater than or equal to the actual arc-starting angle, the programmable logic controller controls the welding torch to descend from the safe height to the welding height, and after the welding torch reaches the welding height, controls the welding power supply to restart the arc.

8. The workpiece welding control method with automatic obstacle avoidance according to claim 1, characterized in that, When the turntable shaft completes one full rotation, the radial axis is controlled to perform a radial feed according to the radial feed amount, and the above steps are repeated until the current position of the radial axis reaches the welding termination radius, specifically including: The programmable logic controller monitors the rotation angle of the turntable shaft in real time. When the cumulative rotation angle of the turntable shaft reaches a full circle, the current number of welding circles is determined to be completed. In response to the completion of the current number of weld overlays, the programmable logic controller reads the current position of the radial axis and compares the current position of the radial axis with the weld overlay termination radius; If the current position of the radial axis is less than the weld termination radius, the programmable logic controller controls the radial axis to move the radial feed amount in the radial direction to reach a new radial position; After the radial axis completes the radial feed movement, the programmable logic controller recalculates the actual arc-stopping angle and actual arc-starting angle corresponding to each side of the rectangular solderless area based on the new radial position. Repeat the above steps until the current position of the radial axis is greater than or equal to the weld termination radius, at which point the programmable logic controller controls the welding power supply to stop welding.

9. The workpiece welding control method with automatic obstacle avoidance according to claim 2, characterized in that, The method further includes a center welding mode, which specifically includes: The human-computer interaction interface receives a mode selection command. When the mode selection command indicates the center welding mode, the theoretical arc-stopping angle and the theoretical arc-starting angle corresponding to the target side in the rectangular weld-free area are interchanged, and the interchanged angle is superimposed with the angle compensation value to obtain the actual arc-starting angle and the actual arc-stopping angle under the center welding mode. In the center welding mode, the angle corresponding to one end point of the target side of the rectangular weld-free area is used as the center welding arc starting angle, and the angle corresponding to the other end point of the target side is used as the center welding arc stopping angle. The welding gun is controlled to start the arc from one side of the target side and weld along the circular trajectory to stop the arc on the other side of the target side, so as to form a crescent-shaped welding layer on one side of the rectangular weld-free area. After each crescent-shaped weld overlay is completed, the radial axis is controlled to perform a radial feed according to the radial feed amount, and the arc initiation, weld overlay and arc cessation operations of the center weld overlay mode are repeated at the new radial position until the current position of the radial axis reaches the weld overlay termination radius.

10. A workpiece welding control system with automatic obstacle avoidance, characterized in that, include: The acquisition module is used to acquire workpiece parameters and welding process parameters. The workpiece parameters include the outer radius of the workpiece, the side length of the rectangular weld-free area in the radial direction and the side length in the tangential direction. The welding process parameters include the weld overlay start radius, weld overlay end radius, radial feed amount and angle compensation value. The module is used to establish a coordinate system with the workpiece center as the origin, calibrate the zero point position of the turntable axis and the radial axis, and calculate the critical avoidance radius based on the side length of the rectangular weld-free area in the radial direction and the side length in the tangential direction. The calculation module is used to calculate the angle threshold of each vertex of the rectangular solderless area relative to the origin of the coordinate system based on the side length of the rectangular solderless area in the radial direction and the side length in the tangential direction, and to obtain the current position of the radial axis and the current angle of the turntable axis in real time during the welding process. The judgment module is used to calculate the actual arc-stopping angle and actual arc-starting angle of each side of the rectangle under the current number of welding circles when the current position of the radial axis is determined to be less than or equal to the critical avoidance radius, based on the current position of the radial axis, the side length of the rectangular solderless area along the radial direction, the side length of the rectangular solderless area along the tangential direction, and the angle compensation value. The processing module is used to perform an arc-stopping operation when the current angle of the turntable axis reaches the actual arc-stopping angle, and to perform an arc-starting operation when the current angle of the turntable axis reaches the actual arc-starting angle, based on the actual arc-stopping angle and the actual arc-starting angle. The control module is used to control the radial axis to perform a radial feed according to the radial feed amount when it is detected that the turntable axis has completed a full rotation, and repeat the above steps until the current position of the radial axis reaches the welding termination radius.

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