Multi-welding point synchronous positioning system and method for wax injection machine

Abstract

This application provides a multi-weld point synchronous positioning system and method for a wax injection machine. The system calculates the visual feature coordinates of each weld point to be positioned and extracts the temperature field distribution at different reference marker points. It determines the thermal deformation of each weld point's region, corrects the visual feature coordinates for thermal deformation, and obtains the thermal deformation calibration coordinates for each weld point. It also determines the displacement compensation of each welding actuator along the three-dimensional coordinate axes, drives the actuators to synchronously displace along the three-dimensional coordinate axes to align the nozzle center with the thermal deformation calibration coordinates of the weld point, and determines the positioning reliability of each weld point. When the positioning reliability of all weld points exceeds a preset position reliability threshold, a synchronous positioning completion signal is sent to the wax injection machine. Using this solution, multi-weld point synchronous positioning can be achieved even when the wax mold produced by the wax injection machine undergoes thermal expansion and deformation.

Description

Technical Field

[0001] This application relates to the field of multi-weld point synchronous positioning technology, and more specifically, to a multi-weld point synchronous positioning system and method for a wax injection machine. Background Technology

[0002] Multi-weld point synchronous positioning is a high-precision positioning method for complex assembly and processing scenarios. Its core idea is to identify and calibrate multiple weld points in parallel under the same coordinate reference. By integrating multi-source information such as visual inspection, laser measurement, and reference mark calibration, multi-weld point synchronous positioning technology can simultaneously acquire the spatial feature coordinates of multiple weld points. Based on coordinate mapping and error compensation models, it can achieve collaborative alignment between weld points. This technology typically includes steps such as image acquisition, weld point feature extraction, thermal error correction, and synchronous calculation. Its advantages are that it significantly shortens the positioning time, improves the automation level of welding or assembly, and can effectively adapt to dynamic changes under complex working conditions. It is widely used in aerospace, precision manufacturing, and intelligent equipment fields, providing reliable technical support for multi-weld point collaborative processing.

[0003] In the lost-wax casting process of precision casting, the wax injection machine is the core equipment for wax model forming. It injects wax material (such as paraffin-stearic acid system) at 40-70℃ into the mold. The accuracy of the produced wax model directly determines the quality of the subsequent casting. However, the wax material has a high coefficient of thermal expansion. Uneven cooling after demolding, changes in ambient temperature, or preheating during mold assembly can easily cause non-uniform thermal expansion deformation, leading to offset of the wax model's reference surface and local dimensional deviations. In the mold assembly process, simultaneous positioning of multiple welding points requires precise splicing of multiple individual wax models, with a welding point position deviation of ≤0.3mm. Traditional positioning relies on room temperature fixed tooling, which cannot adapt to the dynamic dimensional changes of the wax model after thermal deformation, easily resulting in welding point misalignment, module splicing errors, and ultimately, casting scrap. Therefore, how to achieve simultaneous positioning of multiple welding points under the condition of thermal expansion deformation of the wax model produced by the wax injection machine has become a challenge for the industry. Summary of the Invention

[0004] This application provides a multi-welding point synchronous positioning system and method for a wax injection machine, which can realize the synchronous positioning of multiple welding points under the condition that the wax mold produced by the wax injection machine undergoes thermal expansion and deformation.

[0005] In a first aspect, this application provides a method for synchronous positioning of multiple solder joints in a wax injection machine, comprising the following steps: Collect visual images of each weld point to be positioned and temperature change data at different reference markers within the area of ​​each weld point to be positioned; Based on the solder joint contour features in the visual image, calculate the visual feature coordinates of each solder joint to be located, and reconstruct the temperature field distribution of each solder joint area to be located based on all temperature change data. The thermal deformation amount of each weld point to be positioned is determined based on all temperature field distributions, and the visual feature coordinates of each weld point to be positioned are corrected for thermal deformation based on all thermal deformation amounts to obtain the thermal deformation calibration coordinates of each weld point to be positioned. The displacement compensation amount of each welding actuator in the three-dimensional coordinate axis direction is determined based on the spatial displacement deviation between the thermal deformation calibration coordinates and the reference coordinates of each weld point to be positioned. Based on all the displacement compensation amounts, each welding actuator is driven to move synchronously along the three-dimensional coordinate axis so that the center of the welding nozzle is aligned with the thermal deformation calibration coordinates of the corresponding weld point to be positioned. The positioning reliability of each welding point is determined based on the vertical distance deviation and horizontal offset error between the center of each welding nozzle and the surface of the corresponding welding point to be positioned. When the positioning reliability of all welding points to be positioned is higher than the preset positioning reliability threshold, a synchronous positioning completion signal is sent to the wax injection machine.

[0006] In some embodiments, calculating the visual feature coordinates of each solder joint to be located based on the solder joint contour features in the visual image specifically includes: The visual image is preprocessed to determine the solder joint contour features of the preprocessed visual image. The geometric center of the weld point contour of each weld point to be located is determined by the weld point contour features. Based on the pre-calibrated camera parameters and the coordinate system calibration parameters of the wax injection machine's worktable, the geometric center of the weld point contour of each weld point to be positioned is transformed from the image coordinate system to the world coordinate system, thus obtaining the visual feature coordinates of each weld point to be positioned.

[0007] In some embodiments, reconstructing the temperature field distribution of each weld point region to be located based on all temperature change data specifically includes: Select one solder joint to be positioned as the selected solder joint to be positioned. Based on the temperature change data and calibration coordinates at at least five different reference markers within the selected area to be located solder joint, the temperature values ​​at different locations within the selected area to be located solder joint are interpolated to obtain the temperature field distribution of the selected area to be located solder joint. The number of reference markers meets the spatial sampling density threshold to ensure reconstruction accuracy. Continue to determine the temperature field distribution in the remaining areas of the welding points to be positioned.

[0008] In some embodiments, determining the thermal deformation of each weld point region to be positioned based on all temperature field distributions specifically includes: Based on the spatial relationship between each weld point to be positioned and the reference mark, all weld points to be positioned are divided into different heat-affected zones. Select one solder joint to be positioned as the selected solder joint to be positioned. The thermal displacement of the selected weld point area in the horizontal direction is determined based on the temperature field distribution of the selected weld point area, the thermal expansion coefficient of the base material of the selected weld point area, the initial size and the constraint conditions. The thermal expansion coefficient is obtained from the material database and takes into account the temperature range variation. The constraint conditions are evaluated based on the wax mold fixing fixture. The thermal deformation of the selected weld point area is determined by the horizontal thermal displacement of the selected weld point area. Continue to determine the amount of thermal deformation in the remaining areas of the weld points to be positioned.

[0009] In some embodiments, thermal deformation correction is performed on the visual feature coordinates of each weld point to be positioned based on all thermal deformation amounts to obtain the thermal deformation calibration coordinates of each weld point to be positioned, specifically including: The displacement synchronous calibration value of the visual feature coordinates of each weld point to be positioned is determined based on the thermal deformation of each weld point area. By synchronously correcting the visual feature coordinates of each weld point to be located using all displacement synchronous calibration values, the thermal deformation calibration coordinates of each weld point to be located are obtained.

[0010] In some embodiments, determining the displacement compensation amount of each welding actuator in the three-dimensional coordinate axis direction based on the spatial displacement deviation between the thermal deformation calibration coordinates and the reference coordinates of each weld point to be positioned specifically includes: Obtain the reference coordinates of each weld point to be positioned; Determine the spatial displacement deviation between the thermal deformation calibration coordinates and the reference coordinates of each weld point to be positioned; The driving displacement of each welding actuator is determined based on the spatial displacement deviation between the thermal deformation calibration coordinates and the reference coordinates of each weld point to be positioned, the kinematic mapping relationship between each welding actuator and its corresponding weld point to be positioned, and the differences in the dynamic characteristics of the actuators. The differences in dynamic characteristics include load and response time. Inverse kinematics calculations are performed on the driving displacement of each welding actuator to obtain the displacement compensation of each welding actuator in the three-dimensional coordinate axis direction.

[0011] In some embodiments, driving each welding actuator to move synchronously along the three-dimensional coordinate axis according to all displacement compensation amounts to align the welding nozzle center with the thermal deformation calibration coordinates of the corresponding weld point to be positioned specifically includes: The displacement compensation of each welding actuator in the three-dimensional coordinate axis direction is sent to the multi-axis motion controller; A multi-axis motion controller generates coordinated motion commands to control all welding actuators to move synchronously according to a unified clock beat and a planned motion trajectory. The coordinated motion commands use electronic gears to compensate for differences in the dynamic response of the actuators to ensure synchronization. Control each welding actuator to move synchronously according to the planned motion trajectory, and provide real-time feedback on the center position coordinates of the welding nozzle; During the movement, the displacement of each axis is dynamically and collaboratively adjusted until the error between the center coordinate of the welding nozzle and the thermal deformation calibration coordinate of the corresponding welding point to be positioned by the welding actuator is less than the tolerance threshold.

[0012] In some embodiments, determining the positioning reliability of each weld point based on the vertical distance deviation and horizontal offset error between the center of each welding nozzle and the surface of the corresponding weld point to be positioned specifically includes: Measure the vertical distance deviation between the center of each welding nozzle and the normal direction of the surface of the welding point to be positioned; Simultaneously detect the horizontal offset error of the center of all welding nozzles within the tangential plane of their respective welding points; The positioning error of each weld point to be positioned is determined based on all vertical distance deviations and all horizontal offset errors. The positioning reliability of each weld point to be positioned is determined by the positioning error of each weld point to be positioned, the preset error weight parameters, and the statistical error characteristics of the measuring equipment. The statistical error characteristics include the standard deviation and confidence interval to quantify the reliability.

[0013] In some embodiments, when the positioning confidence of all weld points to be positioned is higher than a preset positioning confidence threshold, sending a synchronous positioning completion signal to the wax injection machine specifically includes: Obtain the preset location confidence threshold; Poll and check whether the positioning reliability of all weld points to be positioned is higher than the positioning reliability threshold; If there is a weld point to be located that is below the position confidence threshold, the welding actuator corresponding to the weld point to be located will be driven to perform a secondary correction. If the positioning confidence of all the weld points to be positioned is higher than the positioning confidence threshold, then a synchronous positioning completion signal is sent to the wax injection machine.

[0014] Secondly, this application provides a multi-welding point synchronous positioning system for a wax injection machine, comprising: The acquisition module is used to acquire visual images of each weld point to be located and temperature change data at different reference markers within the area of ​​each weld point to be located; The processing module is used to calculate the visual feature coordinates of each solder joint to be located based on the solder joint contour features in the visual image, and to reconstruct the temperature field distribution of each solder joint area to be located based on all temperature change data. The processing module is also used to determine the thermal deformation amount of each weld point area to be positioned based on all temperature field distributions, and to perform thermal deformation correction on the visual feature coordinates of each weld point to be positioned based on all thermal deformation amounts, so as to obtain the thermal deformation calibration coordinates of each weld point to be positioned. The processing module is also used to determine the displacement compensation amount of each welding actuator in the three-dimensional coordinate axis direction based on the spatial displacement deviation between the thermal deformation calibration coordinates and the reference coordinates of each weld point to be positioned, and drive each welding actuator to move synchronously along the three-dimensional coordinate axis according to all the displacement compensation amounts so that the center of the welding nozzle is aligned with the thermal deformation calibration coordinates of the corresponding weld point to be positioned. The execution module is used to determine the positioning reliability of each welding point based on the vertical distance deviation and horizontal offset error between the center of each welding nozzle and the surface of the corresponding welding point to be positioned. When the positioning reliability of all welding points to be positioned is higher than the preset positioning reliability threshold, a synchronous positioning completion signal is sent to the wax injection machine.

[0015] The technical solutions provided by the embodiments disclosed in this application have the following beneficial effects: The multi-solder point synchronous positioning system and method for wax injection machine provided in this application involves acquiring visual images of each solder point to be positioned and temperature change data at different reference marker points within the area of ​​each solder point to be positioned; calculating the visual feature coordinates of each solder point to be positioned based on the solder point contour features in the visual images; reconstructing the temperature field distribution of the area of ​​each solder point to be positioned based on all temperature change data; determining the thermal deformation amount of the area of ​​each solder point to be positioned based on all temperature field distributions; and performing thermal deformation correction on the visual feature coordinates of each solder point to be positioned based on all thermal deformation amounts to obtain the thermal deformation calibration coordinates of each solder point to be positioned. The displacement compensation amount of each welding actuator in the three-dimensional coordinate axis direction is determined based on the spatial displacement deviation between the thermal deformation calibration coordinates and the reference coordinates of each weld point to be positioned. Based on all the displacement compensation amounts, each welding actuator is driven to move synchronously along the three-dimensional coordinate axis so that the center of the welding nozzle is aligned with the thermal deformation calibration coordinates of the corresponding weld point to be positioned. The positioning reliability of each weld point to be positioned is determined based on the vertical distance deviation and horizontal offset error between the center of each welding nozzle and the surface of the corresponding weld point to be positioned. When the positioning reliability of all weld points to be positioned is higher than the preset positioning reliability threshold, a synchronous positioning completion signal is sent to the wax injection machine.

[0016] Therefore, this application can determine the positioning reliability of each weld point based on the vertical distance deviation and horizontal offset error between the center of each welding nozzle and the surface of the corresponding weld point to be positioned. Firstly, by collecting visual images and temperature change data of each weld point area, a dual-modal information source of visual features and thermal field distribution is established. This ensures that positioning not only relies on static geometric features but also incorporates temperature field data reflecting the dynamic thermal behavior of the wax model, fundamentally solving the unpredictable dimensional deviations caused by uneven cooling or environmental temperature changes in the wax model. Secondly, by extracting the visual feature coordinates of the weld points to be positioned from the visual images and calculating the thermal deformation of the weld point area in conjunction with the temperature field distribution, thermal correction of the weld point coordinates is achieved. This allows the position of each weld point to be positioned to be adaptively calibrated according to the dynamic dimensions under actual thermal conditions, ensuring that subsequent positioning accuracy is no longer limited by the non-uniform expansion and contraction during wax model demolding or mold assembly. Furthermore, by calibrating the thermal deformation of the weld points to be positioned... By comparing the coordinates with the reference coordinates in space, the displacement compensation of each welding actuator in three dimensions is obtained, and all actuators are driven to adjust synchronously, realizing the coordinated alignment of multiple welding points. This avoids the overall misalignment problem caused by local thermal deformation differences, and significantly improves the spatial consistency and assembly reliability of the model assembly process. In addition, the vertical distance deviation and horizontal offset error between the welding nozzle center and the surface of the welding point to be positioned are introduced as evaluation indicators of positioning reliability. A positioning reliability threshold is set to determine whether synchronous positioning is completed. This not only gives the positioning process a quantitative self-checking and fault tolerance capability, but also effectively reduces the risk of welding point misalignment caused by the accumulation of small errors. It can be seen that this method can realize the synchronous positioning of multiple welding points of the wax model while dynamically compensating for the dimensional deviation caused by thermal deformation, thereby ensuring that the welding point positioning accuracy meets the process requirements. In summary, the solution of this application can realize the synchronous positioning of multiple welding points under the condition that the wax model produced by the wax injection machine undergoes thermal expansion deformation. Attached Figure Description

[0017] Figure 1 This is an exemplary flowchart of a multi-welding point synchronous positioning method for a wax injection machine according to some embodiments of this application; Figure 2 This is a schematic flowchart illustrating the determination of displacement compensation amount according to some embodiments of this application; Figure 3 This is a schematic flowchart illustrating the process of determining location reliability according to some embodiments of this application; Figure 4 This is a schematic diagram of the structure of a multi-welding point synchronous positioning system for a wax injection machine according to some embodiments of this application; Figure 5 This is a schematic diagram of the structure of a computer device for implementing a multi-welding point synchronous positioning method for a wax injection machine, according to some embodiments of this application. Detailed Implementation

[0018] To better understand the technical solution of this application, the technical solution of this application will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0019] refer to Figure 1 The figure is an exemplary flowchart of a multi-weld point synchronous positioning method for a wax injection machine according to some embodiments of this application. The multi-weld point synchronous positioning method for a wax injection machine mainly includes the following steps: In step 101, visual images of each solder joint to be located and temperature change data at different reference marker points within the area of ​​each solder joint to be located are collected.

[0020] In practice, an industrial camera is installed above the working area of ​​the wax injection machine. At the same time, multiple non-collinear reference markers are preset around each area to be positioned as a weld point. A non-contact infrared temperature sensor is used to collect temperature change data at each reference marker to avoid local softening of the wax mold. When the data collection is triggered, the industrial camera is simultaneously activated by the equipment arrival signal to capture a visual image of the weld point to be positioned and the infrared temperature sensor collects temperature change data at different reference markers within the area to be positioned as a weld point.

[0021] It should be noted that the temperature change data described in this application refers to temperature sequence data formed by continuously acquiring temperature values ​​at a preset frequency, with timestamps as the index and corresponding one-to-one with the acquisition time.

[0022] In step 102, the visual feature coordinates of each solder joint to be located are calculated based on the solder joint contour features in the visual image, and the temperature field distribution of each solder joint area to be located is reconstructed based on all temperature change data.

[0023] In some embodiments, calculating the visual feature coordinates of each solder joint to be located based on the solder joint contour features in the visual image can be achieved using the following steps: The visual image is preprocessed to determine the solder joint contour features of the preprocessed visual image. The geometric center of the weld point contour of each weld point to be located is determined by the weld point contour features. Based on the pre-calibrated camera parameters and the coordinate system calibration parameters of the wax injection machine worktable, the geometric center of the weld point contour of each weld point to be located is transformed from the image coordinate system to the world coordinate system to obtain the visual feature coordinates of each weld point to be located. The calibration parameters are obtained by hand-eye calibration method to ensure the uniformity of the coordinate system.

[0024] It should be noted that the visual feature coordinates described in this application represent the three-dimensional coordinates of the weld point to be positioned in the coordinate system of the wax injection machine worktable.

[0025] In specific implementation, firstly, in the preprocessing stage of the visual image, denoising, enhancement (e.g., improving the grayscale contrast between the solder joints and the background through histogram equalization), and edge detection are performed sequentially. Further, the edge contours of each solder joint to be located are extracted, for example, using a contour extraction algorithm (such as the findContours function in OpenCV). No specific limitation is made here, and the edge contours of each solder joint to be located are used as the solder joint contour features of the preprocessed visual image. Secondly, a centroid calculation method based on contour moments is used to calculate the edge contour features of each solder joint to be located. The center coordinates of the positioning solder joints are used as the geometric center of the solder joint outline of each solder joint to be positioned. Finally, the camera intrinsic parameter matrix (including focal length and principal point coordinates), distortion coefficients and extrinsic parameters (rotation matrix and translation vector of the camera and the wax injection machine stage) are obtained in advance through the Zhang Zhengyou calibration method, and the coordinate system calibration parameters of the wax injection machine stage are obtained. Then, the three-dimensional coordinates of the geometric center of the solder joint outline of each solder joint to be positioned in the world coordinate system are calculated, and the obtained three-dimensional coordinates are used as the visual feature coordinates of each solder joint to be positioned, so as to ensure that the visual coordinate system is aligned with the mechanical coordinate system of the wax injection machine.

[0026] In some embodiments, reconstructing the temperature field distribution of each weld point region to be located based on all temperature change data can be achieved using the following steps: Select one solder joint to be positioned as the selected solder joint to be positioned. Based on the temperature change data and calibration coordinates at at least five different reference markers within the selected area to be located solder joint, the temperature values ​​at different locations within the selected area to be located solder joint are interpolated to obtain the temperature field distribution of the selected area to be located solder joint. The number of reference markers meets the spatial sampling density threshold to ensure reconstruction accuracy. Continue to determine the temperature field distribution in the remaining areas of the welding points to be positioned.

[0027] It should be noted that the calibration coordinates at the reference mark point in this application represent the fixed position of the reference mark point calibrated at room temperature, and the temperature field distribution represents the spatial distribution of temperature values ​​within the area of ​​the solder joint to be located.

[0028] In practice, the selected area of ​​the solder joint to be located is divided into a uniform grid (the grid size is set based on the area, for example, each grid has a side length of 1 mm). The grid division can be done using the finite element method or other grid division methods, which are not specifically limited here. Then, combined with the temperature change data and calibration coordinates at at least five reference points, spatial interpolation is performed on the temperature values ​​at different locations within the selected area of ​​the solder joint to be located. This ensures that the sampling points cover the edge and center of the area to meet the spatial sampling density threshold (for example, the minimum sampling density is 5 points per square centimeter). The spatial distribution of the temperature values ​​within the selected area of ​​the solder joint to be located is obtained, and the obtained spatial distribution is used as the temperature field distribution of the selected area of ​​the solder joint to be located. The spatial interpolation can use the Kriging interpolation algorithm or other interpolation algorithms, which are not specifically limited here.

[0029] In step 103, the thermal deformation amount of each weld point to be positioned is determined according to all temperature field distributions, and the visual feature coordinates of each weld point to be positioned are corrected for thermal deformation based on all thermal deformation amounts to obtain the thermal deformation calibration coordinates of each weld point to be positioned.

[0030] In some embodiments, determining the thermal deformation of each weld point region to be positioned based on all temperature field distributions can be achieved using the following steps: Based on the spatial relationship between each weld point to be positioned and the reference mark, all weld points to be positioned are divided into different heat-affected zones. Select one solder joint to be positioned as the selected solder joint to be positioned. The thermal displacement of the selected weld point area in the horizontal direction is determined based on the temperature field distribution of the selected weld point area, the thermal expansion coefficient of the base material of the selected weld point area, the initial size and the constraint conditions. The thermal expansion coefficient is obtained from the material database and takes into account the temperature range variation. The constraint conditions are evaluated based on the wax mold fixing fixture. The thermal deformation of the selected weld point area is determined by the horizontal thermal displacement of the selected weld point area. Continue to determine the amount of thermal deformation in the remaining areas of the weld points to be positioned.

[0031] It should be noted that the thermal displacement amount mentioned in this application represents the displacement increment of the area of ​​the solder joint to be positioned in the horizontal direction, and the thermal deformation amount represents the offset of the center of the solder joint in the area where the solder joint to be positioned is located relative to its initial position at room temperature.

[0032] In practice, firstly, based on the spatial relationship between each solder joint to be positioned and the reference marker (e.g., an Euclidean distance threshold of 5mm), all solder joints to be positioned are divided into different heat-affected zones (e.g., radial or gridded zones). Then, the average temperature of the selected solder joint area is extracted from the temperature field distribution. The temperature difference ΔT between the average temperature and the ambient reference temperature (e.g., 25℃) is calculated. Finally, the coefficient of thermal expansion of the base material of the selected solder joint area is retrieved from the material database (e.g., the coefficient of thermal expansion of wax takes into account temperature range variations, such as 100×10⁻⁶ in the 40-70℃ range). -6 / ℃), and evaluate the constraints (e.g., the stress suppression coefficient of 0.8 caused by the wax model being fixed on the tooling table), and then substitute them into the thermal expansion formula: the thermal displacement of the selected solder joint area in the X-axis direction ΔLx = α × L0 × ΔT × (1 - constraint suppression coefficient), where L0 is the initial size (which can be obtained from the design drawings), and α is the thermal expansion coefficient. Similarly, the thermal displacement of the selected solder joint area in the Y-axis direction can be obtained. Secondly, if the temperature field distribution of the selected solder joint area is uniform (i.e., the maximum temperature difference of the area is ≤3℃), the thermal displacement of the selected solder joint area in the X-axis direction is taken as the thermal deformation of the selected solder joint area. If the temperature field distribution of the selected solder joint area is not uniform, take a 5mm core area around the center of the selected solder joint, recalculate the thermal displacement ΔLx' on the X-axis and the thermal displacement ΔLy' on the Y-axis of the core area, and take the thermal displacement ΔLy' on the Y-axis as the thermal deformation of the selected solder joint area.

[0033] In some embodiments, the thermal deformation correction of the visual feature coordinates of each weld point to be positioned based on all thermal deformation amounts can be achieved by the following steps: The displacement synchronous calibration value of the visual feature coordinates of each weld point to be positioned is determined based on the thermal deformation of each weld point area. By synchronously correcting the visual feature coordinates of each weld point to be located using all displacement synchronous calibration values, the thermal deformation calibration coordinates of each weld point to be located are obtained. The correction process integrates the unified calibration of the visual coordinate system and the temperature field coordinate system to avoid coordinate deviation.

[0034] It should be noted that the displacement synchronization calibration value mentioned in this application represents the quantitative parameter of calibrating the displacement of visual feature coordinates under the same time reference; the thermal deformation calibration coordinate represents the calibration coordinate of the weld point to be positioned after eliminating the influence of thermal deformation of the wax injection machine.

[0035] In specific implementation, firstly, all thermal deformation quantities are linearly fitted, for example, using existing linear fitting algorithms (such as Gaussian process regression algorithm) to obtain thermal deformation curves. The values ​​on the thermal deformation curves are all used as thermal deformation fitted values, where each thermal deformation fitted value corresponds to a thermal deformation quantity. Then, the thermal deformation quantity of each solder joint area to be located is subtracted from the corresponding thermal deformation fitted value, and the subtraction result is used as the displacement synchronous calibration value of the visual feature coordinates of each solder joint to be located. Secondly, for each solder joint to be located, the displacement synchronous calibration value of the solder joint to be located is added to the visual feature coordinates of the solder joint to be located (i.e., initial X coordinate value + displacement synchronous calibration value, initial Y coordinate value + displacement synchronous calibration value, initial Z coordinate value + displacement synchronous calibration value). During the correction process, the unified calibration of the visual coordinate system and the temperature field coordinate system is integrated (coordinate alignment is ensured through pre-calibrated hand-eye calibration and sensor calibration) to avoid coordinate deviation. The coordinates obtained after adding the displacement synchronous calibration value are used as the thermal deformation calibration coordinates of the solder joint to be located, thus obtaining the thermal deformation calibration coordinates of each solder joint to be located.

[0036] In step 104, the displacement compensation amount of each welding actuator in the three-dimensional coordinate axis direction is determined according to the spatial displacement deviation between the thermal deformation calibration coordinates and the reference coordinates of each weld point to be positioned. Based on all the displacement compensation amounts, each welding actuator is driven to move synchronously along the three-dimensional coordinate axis so that the center of the welding nozzle is aligned with the thermal deformation calibration coordinates of the corresponding weld point to be positioned.

[0037] In some embodiments, reference Figure 2 As shown in the figure, this is a flowchart illustrating the determination of displacement compensation in some embodiments of this application. In this embodiment, the displacement compensation of each welding actuator in the three-dimensional coordinate axis direction is determined based on the spatial displacement deviation between the thermal deformation calibration coordinates and the reference coordinates of each weld point to be positioned. This can be achieved by the following steps: Obtain the reference coordinates of each weld point to be positioned; Determine the spatial displacement deviation between the thermal deformation calibration coordinates and the reference coordinates of each weld point to be positioned; The driving displacement of each welding actuator is determined based on the spatial displacement deviation between the thermal deformation calibration coordinates and the reference coordinates of each weld point to be positioned, the kinematic mapping relationship between each welding actuator and its corresponding weld point to be positioned, and the differences in the dynamic characteristics of the actuators. The differences in dynamic characteristics include load and response time. Inverse kinematics calculations are performed on the driving displacement of each welding actuator to obtain the displacement compensation of each welding actuator in the three-dimensional coordinate axis direction.

[0038] It should be noted that the reference coordinates mentioned in this application represent the preset standard position coordinates of the weld point to be positioned; the spatial displacement deviation represents the deviation between the position of the weld point to be positioned and the standard position; the kinematic mapping relationship represents the coordinate transformation relationship between the welding actuator and its corresponding weld point to be positioned; the driving displacement represents the displacement amount required for the welding actuator to complete the spatial motion; and the displacement compensation represents the axial displacement parameter that the welding actuator needs to adjust in the three-dimensional coordinate system.

[0039] In specific implementation, firstly, the difference between the thermal deformation calibration coordinates and the reference coordinates of each weld point to be positioned is calculated (i.e., X-axis deviation ΔX = X in thermal deformation calibration coordinates - X in reference coordinates, Y-axis deviation ΔY = Y in thermal deformation calibration coordinates - Y in reference coordinates, Z-axis deviation ΔZ = Z in thermal deformation calibration coordinates - Z in reference coordinates)). The set of X-axis deviations, Y-axis deviations, and Z-axis deviations of the weld point to be positioned is taken as the spatial displacement deviation between the thermal deformation calibration coordinates and the reference coordinates of the weld point to be positioned, thus obtaining the spatial displacement deviation between the thermal deformation calibration coordinates and the reference coordinates of each weld point to be positioned. Secondly, the kinematic model of the welding actuator (e.g., a six-axis robotic arm) is called (established using the Denavit-Hartenberg parametric method and preset in the robot controller). The kinematic model includes... The kinematic mapping relationship between the welding actuator and the weld point to be positioned is established. The spatial displacement deviation between the thermal deformation calibration coordinates and the reference coordinates of each weld point to be positioned is substituted into the kinematic model for forward calculation. The dynamic characteristic differences of the actuators (e.g., response time delay of 0.1s due to load differences) are evaluated. The displacement is adjusted by a compensation algorithm (e.g., PID pre-adjustment) to obtain the displacement amount that each welding actuator needs to move to offset the deviation. The obtained displacement amount is used as the driving displacement amount of each welding actuator. Then, the Newton-Raphson iterative algorithm is used to perform inverse kinematic calculation on the driving displacement amount of each welding actuator. The driving displacement amount is decomposed into the movement value of the robotic arm in the X, Y, and Z axis directions. The obtained movement value is used as the displacement compensation amount, thereby obtaining the displacement compensation amount of each welding actuator in the three-dimensional coordinate axis directions.

[0040] In some embodiments, driving each welding actuator to move synchronously along the three-dimensional coordinate axis according to all displacement compensation amounts to align the welding nozzle center with the thermal deformation calibration coordinates of the corresponding weld point to be positioned can be achieved by the following steps: The displacement compensation of each welding actuator in the three-dimensional coordinate axis direction is sent to the multi-axis motion controller; A multi-axis motion controller generates coordinated motion commands to control all welding actuators to move synchronously according to a unified clock beat and a planned motion trajectory. The coordinated motion commands use electronic gears to compensate for differences in the dynamic response of the actuators to ensure synchronization. Control each welding actuator to move synchronously according to the planned motion trajectory, and provide real-time feedback on the center position coordinates of the welding nozzle; During the movement, the displacement of each axis is dynamically and collaboratively adjusted until the error between the center coordinate of the welding nozzle and the thermal deformation calibration coordinate of the corresponding welding point to be positioned by the welding actuator is less than the tolerance threshold.

[0041] It should be noted that the tolerance threshold mentioned in this application represents the maximum permissible positional deviation value, and the tolerance threshold can be directly obtained from the database of the wax injection machine.

[0042] In practice, firstly, the three-dimensional coordinate axis displacement compensation of each welding actuator is transmitted to a multi-axis motion controller (e.g., Beckhoff CX5140 or Siemens S7-1500T) via an EtherCAT high-speed industrial bus (communication cycle ≤1ms, synchronization error ≤100ns); then, the multi-axis motion controller calls the built-in PLCopen motion control function block, based on distributed clock synchronization technology (e.g., EtherCAT). The DC controller unifies the clock cycle of all welding actuators and uses an S-shaped acceleration / deceleration curve to plan the motion trajectory, generating a coordinated motion command that includes the position and speed setpoints of each welding actuator in each control cycle. Synchronization is ensured by compensating for differences in the dynamic response of the actuators through electronic gears (e.g., adjusting the gear ratio of the actuator with a large load to match the response time). Subsequently, the coordinated motion command is amplified by a servo driver (e.g., Delta ASDA-A3) and drives the welding actuators to move along the trajectory. Simultaneously, a high-precision feedback device (e.g., a 20-bit absolute encoder or grating ruler with a resolution ≤0.05μm) on the welding actuators collects the center position coordinates of the welding nozzle in real time and transmits them back to the controller via a bus. Finally, in each control cycle (typically ≤50μs), the controller calculates the difference between the feedback coordinates and the thermal deformation calibration coordinates of the weld point to be positioned. When the deviation exceeds a preset tolerance threshold, a PID dynamic adjustment algorithm is triggered to fine-tune the displacement of each axis, correcting the synchronization error, until the deviation between the center of all welding nozzles and the corresponding weld point calibration coordinates is less than the tolerance threshold.

[0043] In step 105, the positioning reliability of each welding point is determined based on the vertical distance deviation and horizontal offset error between the center of each welding nozzle and the surface of the corresponding welding point to be positioned. When the positioning reliability of all welding points to be positioned is higher than the preset positioning reliability threshold, a synchronous positioning completion signal is sent to the wax injection machine.

[0044] In some embodiments, reference Figure 3 As shown in the figure, this is a flowchart illustrating the determination of positioning reliability in some embodiments of this application. In this embodiment, the determination of the positioning reliability of each weld point to be positioned based on the vertical distance deviation and horizontal offset error between the center of each welding nozzle and the surface of the corresponding weld point to be positioned can be achieved by the following steps: First, in step 1051, the vertical distance deviation between the center of each welding nozzle and the normal direction of the surface of the welding point to be positioned is measured; Secondly, in step 1052, the horizontal offset error of the center of all welding nozzles in the tangential plane of their respective welding points is detected simultaneously. Then, in step 1053, the positioning error of each weld point to be positioned is determined based on all vertical distance deviations and all horizontal offset errors; Finally, in step 1054, the positioning reliability of each weld point to be positioned is determined by the positioning error of each weld point to be positioned, the preset error weight parameters, and the statistical error characteristics of the measuring equipment. The statistical error characteristics include the standard deviation and confidence interval to quantify the reliability.

[0045] It should be noted that, in this application, the vertical distance deviation refers to the positioning depth deviation of the welding nozzle center in the direction of the normal to the weld point to be positioned; the horizontal offset error represents the degree of positional deviation of the welding nozzle center in the weld point plane; the error weight parameter represents the weight parameter for adjusting the error sensitivity in the three-dimensional coordinate direction. In this application, the error weight parameters are set to ωX=0.3, ωY=0.3, and ωZ=0.4, where ωX represents the error weight in the X-axis direction, ωY represents the error weight in the Y-axis direction, and ωZ represents the error weight in the Z-axis direction; the positioning reliability represents the reliability of the positioning accuracy of the weld point to be positioned.

[0046] In practice, firstly, after locating the welding nozzle center, the vertical distance deviation between the centers of all welding nozzles and the normal direction of the surface of their respective welding points is measured; secondly, the horizontal offset error of the centers of all welding nozzles in the tangent plane of their respective welding points is simultaneously detected; then, for each welding point to be located, the horizontal offset error (ΔX, ΔY) of the welding nozzle center in the tangent plane of the welding point to be located and the vertical distance deviation (ΔZ) between the welding nozzle center and the normal direction of the surface of the welding point to be located are integrated into a three-dimensional spatial vector (ΔX, ΔY, ΔZ), and the magnitude of the three-dimensional spatial vector (√(ΔX²+ΔY²+ΔZ²)) is calculated, and the obtained magnitude is used as the positioning error of the welding point to be located, thus obtaining the positioning error of each welding point to be located. Finally, for each weld point to be positioned, the horizontal offset error (ΔX, ΔY) of the nozzle center in the tangential plane of the weld point and the vertical distance deviation (ΔZ) between the nozzle center and the normal direction of the surface of the weld point are weighted and summed using preset error weighting parameters. The weighted sum is then used as the weighted error of the weld point to be positioned, i.e.: Weighted error = |ΔX|×ωX + |ΔY|×ωY + |ΔZ|×ωZ. The statistical error characteristics of the measuring equipment are then integrated (e.g., standard deviation of 0.02mm and confidence interval of the visual camera), and the positioning reliability of the weld point to be positioned is calculated using the following formula: Positioning reliability of the weld point to be positioned = 1 - (Weighted error of the weld point to be positioned + standard deviation) / (Positioning error of the weld point to be positioned × confidence interval factor). This yields the positioning reliability of each weld point to be positioned, thus quantifying its reliability.

[0047] In some embodiments, when the positioning confidence of all weld points to be positioned is higher than a preset positioning confidence threshold, sending a synchronous positioning completion signal to the wax injection machine can be achieved by the following steps: Obtain the preset location confidence threshold; Poll and check whether the positioning reliability of all weld points to be positioned is higher than the positioning reliability threshold; If there is a weld point to be located below the position confidence threshold, the welding actuator corresponding to the weld point to be located will be driven to perform a secondary correction. The secondary correction takes into account the heat-sensitive characteristics of the wax model to avoid local softening. If the positioning confidence of all the weld points to be positioned is higher than the positioning confidence threshold, then a synchronous positioning completion signal is sent to the wax injection machine.

[0048] It should be noted that the positional reliability threshold in this application represents the critical value for judging whether the positional reliability meets the standard, and the positional reliability threshold can be obtained through small-batch trial welding experiments.

[0049] In practice, a preset position reliability threshold is retrieved from the wax injection machine's database. The multi-axis motion controller polls and checks whether the position reliability of all weld points to be positioned is higher than the position reliability threshold. If the position reliability of any weld point to be positioned is lower than the position reliability threshold, the multi-axis motion controller sends a secondary correction command to the welding actuator corresponding to that weld point via the EtherCAT bus. This drives the actuator to perform small-amplitude displacement compensation along the three-dimensional coordinate axis (e.g., displacement step size of 0.05mm, and controlling the correction temperature below the melting point of the wax model to avoid local softening). After correction, the position reliability of the weld point to be positioned is recalculated and included in the polling again. If two consecutive rounds of polling confirm that the reliability of all weld points is higher than the position reliability threshold, the multi-axis motion controller sends a synchronous positioning completion signal to the main controller of the wax injection machine via the Modbus TCP industrial protocol.

[0050] In another aspect, in some embodiments, this application provides a multi-welding point synchronous positioning system for a wax injection machine, as referenced. Figure 4 The figure is a schematic diagram of a multi-weld point synchronous positioning system for a wax injection machine according to some embodiments of this application. The multi-weld point synchronous positioning system 400 for a wax injection machine includes: a data acquisition module 401, a processing module 402, and an execution module 403, which are described below: The acquisition module 401 in this application is mainly used to acquire visual images of each weld point to be positioned and temperature change data at different reference marker points within the area of ​​each weld point to be positioned. Processing module 402, in this application, is used to calculate the visual feature coordinates of each solder joint to be located based on the solder joint contour features in the visual image, and to reconstruct the temperature field distribution of each solder joint area to be located based on all temperature change data. It should be noted that the processing module 402 described in this application is also used to determine the thermal deformation amount of each weld point area to be positioned based on all temperature field distributions, and to perform thermal deformation correction on the visual feature coordinates of each weld point to be positioned based on all thermal deformation amounts, so as to obtain the thermal deformation calibration coordinates of each weld point to be positioned. In addition, the processing module 402 described in this application is also used to determine the displacement compensation amount of each welding actuator in the three-dimensional coordinate axis direction based on the spatial displacement deviation between the thermal deformation calibration coordinates and the reference coordinates of each weld point to be positioned, and drive each welding actuator to move synchronously along the three-dimensional coordinate axis according to all the displacement compensation amounts so that the center of the welding nozzle is aligned with the thermal deformation calibration coordinates of the corresponding weld point to be positioned. The execution module 403 in this application is mainly used to determine the positioning reliability of each welding point based on the vertical distance deviation and horizontal offset error between the center of each welding nozzle and the surface of the corresponding welding point to be positioned. When the positioning reliability of all welding points to be positioned is higher than the preset positioning reliability threshold, a synchronous positioning completion signal is sent to the wax injection machine.

[0051] In addition, this application also provides a computer device, the computer device including a memory and a processor, the memory storing code, and the processor being configured to acquire the code and execute the above-described multi-welding point synchronous positioning method for a wax injection machine.

[0052] In some embodiments, reference Figure 5 The figure is a schematic diagram of the structure of a computer device for implementing a multi-solder point synchronous positioning method for a wax injection machine according to some embodiments of this application. The multi-solder point synchronous positioning method for a wax injection machine in the above embodiments can be achieved through... Figure 5 The computer device 500 shown is used to implement this, and the computer device 500 includes at least one processor 501, a communication bus 502, a memory 503, and at least one communication interface 504.

[0053] The processor 501 can be a general-purpose central processing unit (CPU), an application-specific integrated circuit (ASIC), or one or more devices used to control the execution of the multi-solder point synchronous positioning method of the wax injection machine in this application.

[0054] The communication bus 502 can be used to transmit information between the aforementioned components.

[0055] Memory 503 may be a read-only memory (ROM) or other type of static storage device capable of storing static information and instructions, random access memory (RAM) or other type of dynamic storage device capable of storing information and instructions, or electrically erasable programmable read-only memory (EEPROM), compact disc read-only memory (CDROM) or other optical disc storage, optical disc storage (including compressed optical discs, laser discs, optical discs, digital versatile optical discs, Blu-ray discs, etc.), magnetic disks or other magnetic storage devices, or any other medium capable of carrying or storing desired program code in the form of instructions or data structures and accessible by a computer, but not limited thereto. Memory 503 may exist independently and be connected to processor 501 via communication bus 502. Memory 503 may also be integrated with processor 501.

[0056] The memory 503 stores program code for executing the scheme of this application, and its execution is controlled by the processor 501. The processor 501 executes the program code stored in the memory 503. The program code may include one or more software modules. The method described in the above method embodiments can be implemented by the processor 501 and one or more software modules in the program code in the memory 503.

[0057] Communication interface 504 uses any transceiver-like device to communicate with other devices or communication networks, such as Ethernet, radio access network (RAN), wireless local area networks (WLAN), etc.

[0058] In a specific implementation, as one example, a computer device may include multiple processors, each of which may be a single-core (single CPU) processor or a multi-core (multi CPU) processor. Here, a processor may refer to one or more devices, circuits, and / or processing cores used to process data (e.g., computer program instructions).

[0059] The aforementioned computer device can be a general-purpose computer device or a special-purpose computer device. In specific implementations, the computer device can be a desktop computer, a portable computer, a network server, a handheld digital assistant (PDA), a mobile phone, a tablet computer, a wireless terminal device, a communication device, or an embedded device. This application does not limit the type of computer device.

[0060] In addition, this application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described method for synchronous positioning of multiple solder joints in a wax injection machine.

[0061] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

[0062] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A method for synchronous positioning of multiple welding points in a wax injection machine, characterized in that, Includes the following steps: Collect visual images of each weld point to be positioned and temperature change data at different reference markers within the area of ​​each weld point to be positioned; Based on the solder joint contour features in the visual image, calculate the visual feature coordinates of each solder joint to be located, and reconstruct the temperature field distribution of each solder joint area to be located based on all temperature change data. The thermal deformation amount of each weld point to be positioned is determined based on all temperature field distributions, and the visual feature coordinates of each weld point to be positioned are corrected for thermal deformation based on all thermal deformation amounts to obtain the thermal deformation calibration coordinates of each weld point to be positioned. The thermal deformation calibration coordinates represent the calibration coordinates of the weld point to be positioned after eliminating the influence of thermal deformation of the wax injection machine. The displacement compensation amount of each welding actuator in the three-dimensional coordinate axis direction is determined based on the spatial displacement deviation between the thermal deformation calibration coordinates and the reference coordinates of each weld point to be positioned. Based on all the displacement compensation amounts, each welding actuator is driven to move synchronously along the three-dimensional coordinate axis so that the center of the welding nozzle is aligned with the thermal deformation calibration coordinates of the corresponding weld point to be positioned. The positioning reliability of each welding point is determined based on the vertical distance deviation and horizontal offset error between the center of each welding nozzle and the surface of the corresponding welding point to be positioned. When the positioning reliability of all welding points to be positioned is higher than the preset positioning reliability threshold, a synchronous positioning completion signal is sent to the wax injection machine.

2. The method as described in claim 1, characterized in that, Calculating the visual feature coordinates of each solder joint to be located based on the solder joint contour features in the visual image specifically includes: The visual image is preprocessed to determine the solder joint contour features of the preprocessed visual image. The geometric center of the weld point contour of each weld point to be located is determined by the weld point contour features. Based on the pre-calibrated camera parameters and the coordinate system calibration parameters of the wax injection machine's worktable, the geometric center of the weld point contour of each weld point to be positioned is transformed from the image coordinate system to the world coordinate system, thus obtaining the visual feature coordinates of each weld point to be positioned.

3. The method as described in claim 1, characterized in that, Reconstructing the temperature field distribution of each weld point area based on all temperature change data specifically includes: Select one solder joint to be positioned as the selected solder joint to be positioned. Based on the temperature change data and calibration coordinates at at least five different reference markers within the selected area to be located solder joint, the temperature values ​​at different locations within the selected area to be located solder joint are interpolated to obtain the temperature field distribution of the selected area to be located solder joint. The number of reference markers meets the spatial sampling density threshold to ensure reconstruction accuracy. Continue to determine the temperature field distribution in the remaining areas of the welding points to be positioned.

4. The method as described in claim 1, characterized in that, The thermal deformation of each weld point area to be positioned is determined based on all temperature field distributions, specifically including: Based on the spatial relationship between each weld point to be positioned and the reference mark, all weld points to be positioned are divided into different heat-affected zones. Select one solder joint to be positioned as the selected solder joint to be positioned. The thermal displacement of the selected weld point area in the horizontal direction is determined based on the temperature field distribution of the selected weld point area, the thermal expansion coefficient of the base material of the selected weld point area, the initial size and the constraint conditions. The thermal expansion coefficient is obtained from the material database and takes into account the temperature range variation. The constraint conditions are evaluated based on the wax mold fixing fixture. The thermal deformation of the selected weld point area is determined by the horizontal thermal displacement of the selected weld point area. Continue to determine the amount of thermal deformation in the remaining areas of the weld points to be positioned.

5. The method as described in claim 1, characterized in that, Based on all thermal deformation amounts, the visual feature coordinates of each weld point to be positioned are corrected for thermal deformation to obtain the thermal deformation calibration coordinates of each weld point to be positioned, specifically including: The displacement synchronous calibration value of the visual feature coordinates of each weld point to be positioned is determined based on the thermal deformation of each weld point area. By synchronously correcting the visual feature coordinates of each weld point to be located using all displacement synchronous calibration values, the thermal deformation calibration coordinates of each weld point to be located are obtained.

6. The method as described in claim 1, characterized in that, The displacement compensation amount of each welding actuator in the three-dimensional coordinate axis direction is determined based on the spatial displacement deviation between the thermal deformation calibration coordinates and the reference coordinates of each weld point to be positioned. Specifically, this includes: Obtain the reference coordinates of each weld point to be positioned; Determine the spatial displacement deviation between the thermal deformation calibration coordinates and the reference coordinates of each weld point to be positioned; The driving displacement of each welding actuator is determined based on the spatial displacement deviation between the thermal deformation calibration coordinates and the reference coordinates of each weld point to be positioned, the kinematic mapping relationship between each welding actuator and its corresponding weld point to be positioned, and the differences in the dynamic characteristics of the actuators. The differences in dynamic characteristics include load and response time. Inverse kinematics calculations are performed on the driving displacement of each welding actuator to obtain the displacement compensation of each welding actuator in the three-dimensional coordinate axis direction.

7. The method as described in claim 1, characterized in that, Based on all displacement compensation values, each welding actuator is driven to move synchronously along the three-dimensional coordinate axis to align the welding nozzle center with the thermal deformation calibration coordinates of the corresponding weld point to be positioned. Specifically, this includes: The displacement compensation of each welding actuator in the three-dimensional coordinate axis direction is sent to the multi-axis motion controller; A multi-axis motion controller generates coordinated motion commands to control all welding actuators to move synchronously according to a unified clock beat and a planned motion trajectory. The coordinated motion commands use electronic gears to compensate for differences in the dynamic response of the actuators to ensure synchronization. Control each welding actuator to move synchronously according to the planned motion trajectory, and provide real-time feedback on the center position coordinates of the welding nozzle; During the movement, the displacement of each axis is dynamically and collaboratively adjusted until the error between the center coordinate of the welding nozzle and the thermal deformation calibration coordinate of the corresponding welding point to be positioned by the welding actuator is less than the tolerance threshold.

8. The method as described in claim 1, characterized in that, The positioning reliability of each weld point is determined based on the vertical distance deviation and horizontal offset error between the center of each welding nozzle and the surface of the corresponding weld point to be positioned. This specifically includes: Measure the vertical distance deviation between the center of each welding nozzle and the normal direction of the surface of the welding point to be positioned; Simultaneously detect the horizontal offset error of the center of all welding nozzles within the tangential plane of their respective welding points; The positioning error of each weld point to be positioned is determined based on all vertical distance deviations and all horizontal offset errors. The positioning reliability of each weld point to be positioned is determined by the positioning error of each weld point to be positioned, the preset error weight parameters, and the statistical error characteristics of the measuring equipment. The statistical error characteristics include the standard deviation and confidence interval to quantify the reliability.

9. The method as described in claim 1, characterized in that, When the positioning confidence of all weld points to be positioned is higher than the preset positioning confidence threshold, a synchronous positioning completion signal is sent to the wax injection machine, specifically including: Obtain the preset location confidence threshold; Poll and check whether the positioning reliability of all weld points to be positioned is higher than the positioning reliability threshold; If there is a weld point to be located that is below the position confidence threshold, the welding actuator corresponding to the weld point to be located will be driven to perform a secondary correction. If the positioning confidence of all the weld points to be positioned is higher than the positioning confidence threshold, then a synchronous positioning completion signal is sent to the wax injection machine.

10. A multi-welding point synchronous positioning system for a wax injection machine, wherein the method described in any one of claims 1 to 9 is used for multi-welding point synchronous positioning in the wax injection machine, characterized in that, The system includes: The acquisition module is used to acquire visual images of each weld point to be located and temperature change data at different reference markers within the area of ​​each weld point to be located; The processing module is used to calculate the visual feature coordinates of each solder joint to be located based on the solder joint contour features in the visual image, and to reconstruct the temperature field distribution of each solder joint area to be located based on all temperature change data. The processing module is also used to determine the thermal deformation amount of each weld point area to be positioned based on all temperature field distributions, and to perform thermal deformation correction on the visual feature coordinates of each weld point to be positioned based on all thermal deformation amounts, so as to obtain the thermal deformation calibration coordinates of each weld point to be positioned. The processing module is also used to determine the displacement compensation amount of each welding actuator in the three-dimensional coordinate axis direction based on the spatial displacement deviation between the thermal deformation calibration coordinates and the reference coordinates of each weld point to be positioned, and drive each welding actuator to move synchronously along the three-dimensional coordinate axis according to all the displacement compensation amounts so that the center of the welding nozzle is aligned with the thermal deformation calibration coordinates of the corresponding weld point to be positioned. The execution module is used to determine the positioning reliability of each welding point based on the vertical distance deviation and horizontal offset error between the center of each welding nozzle and the surface of the corresponding welding point to be positioned. When the positioning reliability of all welding points to be positioned is higher than the preset positioning reliability threshold, a synchronous positioning completion signal is sent to the wax injection machine.

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