A method and system for dynamic compensation of multi-pass drawing speed and tension of photovoltaic welding ribbon copper wire based on closed-loop feedback

Abstract

This invention discloses a method and system for dynamic compensation of multi-pass drawing speed and tension of copper wire for photovoltaic welding ribbon based on closed-loop feedback. The method includes: establishing a finite element model of the copper wire drawing process, simulating deformation data under different drawing operations, and determining the optimal drawing operation parameters; setting the working mode of the drawing mechanism according to the optimal parameters, and performing multi-pass continuous drawing; acquiring the copper wire traction speed and actual tension at each sampling moment within each control cycle, and calculating the transmission speed deviation and tension fluctuation deviation; at each control moment, the first set of PID controllers adjusts the speed of the traction wheel group according to the transmission speed deviation, and the second set of PID controllers adjusts the tension of the tension control device according to the tension fluctuation deviation. This invention also introduces feedforward compensation to improve the dynamic quality of tension control. This invention can reduce the trial-and-error cost of process parameters, suppress speed and tension fluctuations in real time, prevent wire breakage and dimensional deviations, and improve the yield of drawn wire.

Description

Technical Field

[0001] This invention relates to the field of wire drawing control technology, and in particular to a method and system for dynamic compensation of multi-pass wire drawing speed and tension of photovoltaic welding strip copper wire based on closed-loop feedback. Background Technology

[0002] Copper wire for photovoltaic soldering strips is typically produced using a multi-pass continuous drawing process. During the drawing process, the copper wire passes through multiple drawing dies sequentially, with a certain tensile force applied in each pass, gradually reducing the cross-sectional area of ​​the copper wire to the target size. This process requires the proper setting of two key factors: first, the number of drawing passes and the diameter reduction ratio of each pass (i.e., drawing process parameters); second, real-time control of the traction speed and copper wire tension during operation.

[0003] However, existing technologies have the following problems: The wire drawing process parameters rely heavily on manual experience, resulting in high trial-and-error costs: the optimal number of drawing passes and the diameter reduction ratio for each pass vary depending on the specifications of the copper wire (different initial diameters and material conditions). Currently, these parameters are mainly determined by the operator's experience or repeated trial drawing. Each time the batch or specification of copper wire is changed, multiple machine stops are required for adjustment, which is time-consuming and material-intensive, and it is difficult to guarantee the optimality of the parameters.

[0004] Speed ​​and tension fluctuations during wire drawing can easily lead to wire breakage or dimensional deviations: In continuous wire drawing operations, due to factors such as traction motor response fluctuations, uneven copper wire material, and die wear, the actual traction speed and tension of the copper wire will frequently deviate from the target value. When speed fluctuations are too large, the draw ratio of the copper wire becomes mismatched between passes, causing diameter deviations (such as excessive ellipticity or localized necking); when tension fluctuations are too large, the copper wire is prone to breakage at the die exit, leading to production interruption. Although traditional PID control is widely used, when faced with complex operating conditions involving multiple passes and varying loads, a single fixed control parameter is difficult to balance fast response and steady-state accuracy.

[0005] In summary, the technical problems that need to be solved are: how to scientifically determine the process parameters for multi-pass wire drawing to reduce trial and error, and how to suppress speed and tension fluctuations in real time during the wire drawing process to prevent wire breakage and dimensional deviations. Summary of the Invention

[0006] To address at least one of the aforementioned technical problems, this invention provides a method and system for dynamic compensation of multi-pass drawing speed and tension of photovoltaic solder ribbon copper wire based on closed-loop feedback.

[0007] This invention provides a method for dynamic compensation of multi-pass drawing speed and tension of photovoltaic solder ribbon copper wire based on closed-loop feedback, including: A finite element model of the copper wire drawing process is established to simulate the deformation data of the copper wire under several drawing operations; based on the deformation data, the optimal drawing operation parameters are determined. Based on the optimal wire drawing operation parameters, the working mode of the wire drawing mechanism is set to perform multiple continuous wire drawing operations on the copper wire. Within each control cycle, perform the following steps: At each sampling moment within the current control cycle, the copper wire traction line speed is acquired, and the transmission speed deviation at that sampling moment is determined based on the difference between the copper wire traction line speed and the target line speed; at each sampling moment within the current control cycle, the actual tension of the copper wire is acquired, and the tension fluctuation deviation at that sampling moment is determined based on the difference between the actual tension of the copper wire and the target tension. At a control moment within the current control cycle, the first set of PID controllers adjusts the speed of the traction wheel group of the wire drawing mechanism according to the conveying speed deviation; the second set of PID controllers adjusts the tension control device tension of the wire drawing mechanism according to the tension fluctuation deviation, thereby correcting the processing state of the copper wire; wherein, the control moment is located within the current control cycle and is later than the last sampling moment in the cycle.

[0008] In one embodiment, prior to establishing the finite element model of the copper wire drawing process, the following steps are included: Images of the copper wire drawing process and material property data of the copper wire are collected for each of several drawing passes; wherein, the drawing process images include three-dimensional images of the copper wire during the drawing process; the material property data include the elastic modulus, yield strength, and elongation mechanical property data of the copper wire during the drawing process; Identify the surface microstructure data and three-dimensional shape and size data of the copper wire during the drawing process from the three-dimensional image; Based on the time information during the wire drawing process, the mechanical property data, the surface microstructure data, and the three-dimensional shape and size data are timestamped and formatted to obtain a data set.

[0009] In one embodiment, establishing a finite element model of the copper wire drawing process to simulate the deformation data of the copper wire under several drawing operations includes: Numerical simulations were performed based on the aforementioned dataset to establish a finite element model of plastic deformation during the copper wire drawing process. Based on the working parameters of the wire drawing mechanism, model constraints are set; wherein, the working parameters include the range of the wire drawing mechanism's transmission speed and the range of the tensile force. Based on the model constraints, the finite element model is analyzed to simulate the deformation data of the copper wire under several drawing operations; wherein, the several drawing operations correspond one-to-one with several drawing operation parameters; the deformation data includes the cross-sectional deformation data and length deformation data of the copper wire during drawing.

[0010] In one embodiment, determining the optimal wire drawing operation parameters based on the deformation data includes: Based on the deformation data corresponding to each of the several wire drawing operations, the deformation data closest to the desired deformation state is determined; wherein, the desired deformation state includes the desired cross-sectional deformation and the desired length deformation within the dimensional tolerance range; The optimal wire drawing operation parameters are determined by the wire drawing passes and the reduction ratio of the diameter of each pass corresponding to the deformation data that is closest to the desired deformation state.

[0011] In one embodiment, setting the working mode of the wire drawing mechanism according to the optimal wire drawing operation parameters and performing multi-pass continuous wire drawing of the copper wire includes: Based on the optimal wire drawing operation parameters, the working mode corresponding to each wire drawing pass of the wire drawing mechanism is determined; wherein, the working mode includes the traction line speed, tensile force magnitude and duration of each wire drawing pass applied to the copper wire by the wire drawing mechanism. Based on the operating mode, a sequence of control commands is generated for the wire drawing mechanism to perform multiple continuous wire drawing operations on the copper wire.

[0012] In one embodiment, a feedforward compensation step is also included: Within each control cycle, the last sampling time of that control cycle is used. Based on historical transmission speed deviations and current tension fluctuation deviations, the future [number]th [number] [unit] is predicted. The instantaneous transmission speed deviation after each sampling period is used as the feedforward compensation amount corresponding to the control moment of the current control cycle; where... The sampling period is This is the time interval from the last sampling moment in the current control cycle to the control moment within that cycle; take... That is, not less than The smallest integer, in the future... The instantaneous transmission speed deviation after each sampling period is used as... Approximate predicted value at time; The prediction of the future The instantaneous transmission speed deviation after one sampling period includes the following steps: Step A1: Based on the last sampling time and before Transmission speed deviation at each sampling time Calculate the weighted memory cumulative amount using the following formula. : ; in, This is the last sampling moment within the current control cycle; The sampling period; The serial numbers of the historical sampling points, from 0 to... , Corresponding to the last sampling time, Corresponding to the previous sampling time, and so on; The length of the history window, taken as a positive integer, ranging from 50 to 100; It is the memory decay factor; For the first The instantaneous transmission speed deviation at each historical sampling moment, where when hour, Measured directly by a speed sensor; This is the weighted cumulative memory amount; Step A2: Based on the actual tension of the copper wire at the last sampling time. The actual tension at the previous sampling time The difference, and the axial stiffness of the copper wire. The instantaneous transmission speed deviation estimated by the physical model is calculated using the following formula. : ; in, and These are the actual tensions of the copper wire at the last sampling moment and the previous sampling moment, respectively. The axial stiffness of the copper wire; The deviation of the instantaneous transmission speed estimated by the physical model; Step A3: Accumulate the weighted memory amount Compared with the physical model estimate By fusing according to the formula, we obtain the future number. Predicted instantaneous transmission speed deviation after one sampling period , will the As the feedforward compensation amount corresponding to the control moment within the current control cycle: ; in, For the future Predicted instantaneous transmission speed deviation after one sampling period; for The corresponding normalization coefficient; For smoothing parameters; As an index weighting factor, when Automatically adjust fusion weights when the value is large; Accordingly, during the control moment within the current control cycle, controlling the first group of PID controllers to adjust the speed of the traction wheel group of the wire drawing mechanism according to the conveying speed deviation includes: The result obtained in step A3 As a feedforward compensation quantity, at the control moment within the current control cycle, the feedforward compensation quantity is added to the output calculated by the first group of PID controllers based on the transmission speed deviation at the last sampling moment within the current control cycle. The sum is used as the target speed command for the traction wheel set, and the traction wheel set is controlled to run according to the target speed command.

[0013] In one embodiment, the second set of PID controllers adjusts the tension control device tension of the wire drawing mechanism according to the tension fluctuation deviation, including: Step B1, the last sampling time in each control cycle Obtain the tension fluctuation deviation at that moment. and its rate of change in, This represents the tension fluctuation deviation at the previous sampling time. Step B2: Based on the absolute value of the tension fluctuation deviation at the last sampling time... The nonlinear correction coefficient of the proportional gain is calculated using the following formula. : ; in, To correct the strength coefficient; This serves as the reference threshold for tension fluctuation deviation; It is the hyperbolic tangent function; Step B3: Based on the rate of change of tension fluctuation deviation at the last sampling time. The nonlinear correction coefficient for the integral gain is calculated using the following formula. : in, This is the attenuation coefficient, expressed in seconds. Step B4: Adjust the nonlinear correction coefficient of the proportional gain. The base proportional gain of the second group of PID controllers The product of these two values ​​serves as the dynamic proportional gain of the second set of PID controllers at the control moment within the current control cycle. The nonlinear correction coefficient of the integral gain Base integral gain of the second group of PID controllers The product of these two values ​​serves as the dynamic integral gain of the second set of PID controllers at the control moment within the current control cycle. ; Step B5: During the control time of the second group of PID controllers within the current control cycle, the dynamic proportional gain is used. and According to the tension fluctuation deviation Calculate the output control quantity, and adjust the tension of the tension control device accordingly.

[0014] Corresponding to the aforementioned method, this embodiment of the invention also provides a dynamic compensation system for multi-pass wire drawing speed and tension of photovoltaic solder ribbon copper wire based on closed-loop feedback, comprising: The model processing module is used to establish a finite element model of the copper wire drawing process, thereby simulating the deformation data of the copper wire under several drawing operations; based on the deformation data, the optimal drawing operation parameters are determined. The wire drawing module is used to set the working mode of the wire drawing mechanism according to the optimal wire drawing operation parameters, and to perform multiple continuous wire drawing of copper wire. The control processing module is used to perform the following steps in each control cycle: At each sampling moment within the current control cycle, the copper wire traction line speed is acquired, and the transmission speed deviation at that sampling moment is determined based on the difference between the copper wire traction line speed and the target line speed; at each sampling moment within the current control cycle, the actual tension of the copper wire is acquired, and the tension fluctuation deviation at that sampling moment is determined based on the difference between the actual tension of the copper wire and the target tension. At a control moment within the current control cycle, the first set of PID controllers adjusts the speed of the traction wheel group of the wire drawing mechanism according to the conveying speed deviation; the second set of PID controllers adjusts the tension control device tension of the wire drawing mechanism according to the tension fluctuation deviation, thereby correcting the processing state of the copper wire; wherein, the control moment is located within the current control cycle and is later than the last sampling moment in the cycle.

[0015] In one embodiment, a feedforward compensation module is further included, for: Within each control cycle, the last sampling time of that control cycle is used. Based on historical transmission speed deviations and current tension fluctuation deviations, the future [number]th [number] [unit] is predicted. The instantaneous transmission speed deviation after each sampling period is used as the feedforward compensation amount corresponding to the control moment of the current control cycle; where... The sampling period is This is the time interval from the last sampling moment in the current control cycle to the control moment within that cycle; take... That is, not less than The smallest integer, in the future... The instantaneous transmission speed deviation after each sampling period is used as... Approximate predicted value at time; The prediction of the future The instantaneous transmission speed deviation after one sampling period includes the following steps: Step A1: Based on the last sampling time and before Transmission speed deviation at each sampling time Calculate the weighted memory cumulative amount using the following formula. : ; in, This is the last sampling moment within the current control cycle; The sampling period; The serial numbers of the historical sampling points, from 0 to... , Corresponding to the last sampling time, Corresponding to the previous sampling time, and so on; The length of the history window, taken as a positive integer, ranging from 50 to 100; It is the memory decay factor; For the first The instantaneous transmission speed deviation at each historical sampling moment, where when hour, Measured directly by a speed sensor; This is the weighted cumulative memory amount; Step A2: Based on the actual tension of the copper wire at the last sampling time. The actual tension at the previous sampling time The difference, and the axial stiffness of the copper wire. The instantaneous transmission speed deviation estimated by the physical model is calculated using the following formula. : ; in, and These are the actual tensions of the copper wire at the last sampling moment and the previous sampling moment, respectively. The axial stiffness of the copper wire; The deviation of the instantaneous transmission speed estimated by the physical model; Step A3: Accumulate the weighted memory amount Compared with the physical model estimate By fusing according to the formula, we obtain the future number. Predicted instantaneous transmission speed deviation after one sampling period , will the As the feedforward compensation amount corresponding to the control moment within the current control cycle: ; in, For the future Predicted instantaneous transmission speed deviation after one sampling period; for The corresponding normalization coefficient; For smoothing parameters; As an index weighting factor, when Automatically adjust fusion weights when the value is large; Accordingly, during the control moment within the current control cycle, controlling the first group of PID controllers to adjust the speed of the traction wheel group of the wire drawing mechanism according to the conveying speed deviation includes: The result obtained in step A3 As a feedforward compensation quantity, at the control moment within the current control cycle, the feedforward compensation quantity is added to the output calculated by the first group of PID controllers based on the transmission speed deviation at the last sampling moment within the current control cycle. The sum is used as the target speed command for the traction wheel set, and the traction wheel set is controlled to run according to the target speed command.

[0016] In one embodiment, the second set of PID controllers adjusts the tension control device tension of the wire drawing mechanism according to the tension fluctuation deviation, including: Step B1, the last sampling time in each control cycle Obtain the tension fluctuation deviation at that moment. and its rate of change in, This represents the tension fluctuation deviation at the previous sampling time. Step B2: Based on the absolute value of the tension fluctuation deviation at the last sampling time... The nonlinear correction coefficient of the proportional gain is calculated using the following formula. : ; in, To correct the strength coefficient; This serves as the reference threshold for tension fluctuation deviation; It is the hyperbolic tangent function; Step B3: Based on the rate of change of tension fluctuation deviation at the last sampling time. The nonlinear correction coefficient for the integral gain is calculated using the following formula. : in, This is the attenuation coefficient, expressed in seconds. Step B4: Adjust the nonlinear correction coefficient of the proportional gain. The base proportional gain of the second group of PID controllers The product of these two values ​​serves as the dynamic proportional gain of the second set of PID controllers at the control moment within the current control cycle. The nonlinear correction coefficient of the integral gain Base integral gain of the second group of PID controllers The product of these two values ​​serves as the dynamic integral gain of the second set of PID controllers at the control moment within the current control cycle. ; Step B5: During the control time of the second group of PID controllers within the current control cycle, the dynamic proportional gain is used. and According to the tension fluctuation deviation Calculate the output control quantity, and adjust the tension of the tension control device accordingly.

[0017] The beneficial effects of the above-mentioned technical solutions provided in the embodiments of the present invention include at least the following: Compared with existing technologies, the method and system for dynamic compensation of multi-pass drawing speed and tension of photovoltaic welding ribbon copper wire provided by this invention based on closed-loop feedback has the following comprehensive effects: The optimal number of drawing passes and diameter reduction ratio are pre-determined through a finite element model, significantly reducing the trial-and-error cost of process parameters; a closed-loop architecture of sampling, prediction, compensation, and control is adopted, real-time acquisition of speed and tension deviations in each control cycle, with the first set of PID controllers correcting the traction speed and the second set of PID controllers adjusting the tension, effectively suppressing speed mismatch and tension fluctuations in multi-pass drawing, reducing the risk of wire breakage and dimensional deviations; furthermore, the weighted memory accumulation of historical speed deviations is adaptively fused with a physical model based on tension changes to generate feedforward compensation, preemptively offsetting dynamic errors caused by feedback delays; simultaneously, the tension PID controller uses nonlinear gain correction, dynamically adjusting the proportional and integral gains according to the deviation amplitude and rate of change, avoiding integral saturation and accelerating the response to large deviations. The overall solution achieves scientific setting of drawing process parameters and precise dynamic compensation during operation, improving the yield and production stability of copper wire drawing.

[0018] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description and the accompanying drawings.

[0019] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0020] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic flowchart of a method for dynamic compensation of multi-pass drawing speed and tension of photovoltaic welding strip copper wire based on closed-loop feedback, provided in an embodiment of the present invention. Detailed Implementation

[0021] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0022] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," "outer," "far," "near," "front," and "rear," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0023] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0024] This invention provides a method for dynamic compensation of multi-pass drawing speed and tension of photovoltaic solder ribbon copper wire based on closed-loop feedback, such as... Figure 1 As shown, it includes the following steps: A finite element model of the copper wire drawing process is established to simulate the deformation data of the copper wire under several drawing operations; based on the deformation data, the optimal drawing operation parameters are determined. Based on the optimal wire drawing operation parameters, the working mode of the wire drawing mechanism is set to perform multiple continuous wire drawing operations on the copper wire. Within each control cycle, perform the following steps: At each sampling moment within the current control cycle, the copper wire traction line speed is acquired, and the transmission speed deviation at that sampling moment is determined based on the difference between the copper wire traction line speed and the target line speed; at each sampling moment within the current control cycle, the actual tension of the copper wire is acquired, and the tension fluctuation deviation at that sampling moment is determined based on the difference between the actual tension of the copper wire and the target tension; where tension fluctuation deviation refers to the difference between the actual tension and the target tension. At a control moment within the current control cycle, the first set of PID controllers adjusts the speed of the traction wheel group of the wire drawing mechanism according to the conveying speed deviation; the second set of PID controllers adjusts the tension control device tension of the wire drawing mechanism according to the tension fluctuation deviation, thereby correcting the processing state of the copper wire; wherein, the control moment is located within the current control cycle and is later than the last sampling moment in the cycle.

[0025] It should be noted that speed control and tension control operate in parallel through two independent PID controllers. The output of the speed loop directly regulates the rotational speed of the traction wheel assembly, while the output of the tension loop changes the tension on the copper wire by adjusting the tension control device (such as a magnetic powder clutch or servo motor). The coupling between the two is naturally decoupled by the elastic deformation of the copper wire itself: speed deviation mainly affects the stretch ratio between adjacent passes, while tension deviation mainly reflects the instantaneous fluctuation of the tension on the copper wire. When the sampling frequency is sufficiently high (typically above 100 Hz), the dynamic responses of speed and tension can be considered approximately independent; therefore, using independent PID control is a feasible and effective method in engineering.

[0026] Compared with existing technologies, the aforementioned method for dynamic compensation of multi-pass drawing speed and tension of photovoltaic solder ribbon copper wire based on closed-loop feedback has at least the following beneficial effects: Reduce the trial and error cost of setting process parameters: By establishing a finite element model of the copper wire drawing process, the deformation data under different drawing operations are simulated, and the optimal drawing operation parameters (number of drawing passes and diameter reduction ratio of each pass) that are closest to the desired deformation state are automatically determined. This eliminates the need to rely on repeated trial and error based on human experience, thus improving the scientific nature and efficiency of parameter setting.

[0027] Real-time suppression of speed and tension fluctuations reduces the risk of wire breakage and dimensional deviations: In each control cycle, the traction line speed and actual tension are obtained through high-frequency sampling. The transmission speed deviation and tension fluctuation deviation are calculated respectively. Two independent PID controllers are used to adjust the speed of the traction wheel group and the tension of the tension control device in real time, so that the actual values ​​of speed and tension are always controlled within the allowable deviation range near the target value. This effectively avoids diameter deviations caused by speed mismatch and copper wire breakage caused by excessive tension.

[0028] In another embodiment, before establishing a finite element model of the copper wire drawing process, the following steps are included: Images of the copper wire drawing process and material property data of the copper wire were collected for each of several drawing passes. The drawing process images included three-dimensional images of the copper wire during the drawing process. The material property data included mechanical property data of the copper wire during the drawing process, such as elastic modulus, yield strength, and elongation. Identify surface microstructure data and three-dimensional shape and size data of copper wire during wire drawing from three-dimensional images; Based on the time information during the wire drawing process, the mechanical property data, surface microstructure data, and three-dimensional shape and size data are timestamped and formatted to obtain a dataset.

[0029] Copper wire drawing involves repeatedly applying tensile force along the length of the copper wire. During this process, the cross-sectional area of ​​the copper wire decreases while its length increases, thus stretching it to form a wire that meets predetermined cross-sectional shape and length requirements. It's understandable that the copper wire continuously thins and lengthens during stretching, and corresponding microstructures form on its surface, including but not limited to cracks. Insufficient tensile force cannot effectively lengthen the wire, while excessive force can exceed the wire's tensile strength, leading to breakage. Therefore, the deformation of copper wire during drawing varies depending on its size, surface microstructure, and tensile strength. To accurately determine the optimal drawing operation for the current copper wire, finite element modeling is necessary to precisely determine the deformation of different parts of the wire during the drawing process.

[0030] Images are captured of the copper wire drawing operation performed in each drawing pass to obtain drawn wire processing images. These images can be, but are not limited to, binocular imaging, and can be, but are not limited to, three-dimensional images of the drawn wire. Simultaneously, mechanical property data of the copper wire during drawing are acquired, including but not limited to the copper wire's elastic modulus, yield strength, and elongation. The drawn wire processing images are then analyzed to obtain surface microstructure data and three-dimensional shape and size data of the copper wire during drawing. The surface microstructure data may include, but is not limited to, surface crack size and location, and surface roughness. The three-dimensional shape and size data may include, but is not limited to, the cross-sectional shape and size of the copper wire, and the length of the copper wire. Considering that the aforementioned mechanical property data, surface microstructure data, and three-dimensional shape and size data are all generated during the wire drawing process, meaning that each time point during the wire drawing process corresponds to one set of mechanical property data, one set of surface microstructure data, and one set of three-dimensional shape and size data, in order to accurately correlate these three types of data in the time domain, based on the time information during the wire drawing process, the mechanical property data, surface microstructure data, and three-dimensional shape and size data are time-stamp aligned and processed into a unified format to obtain a data set. Among them, the aforementioned time-stamp alignment process refers to integrating the mechanical property data, surface microstructure data, and three-dimensional shape and size data corresponding to the same time stamp into the same data subset, and processing all data within the aforementioned data subset into a unified format.

[0031] In another embodiment, a finite element model of the copper wire drawing process is established to simulate the deformation data of the copper wire under several drawing operations, including: Numerical simulations were performed based on the dataset to establish a finite element model of plastic deformation during the copper wire drawing process. Based on the working parameters of the wire drawing mechanism, model constraints are set; among which, the working parameters include the range of the wire drawing mechanism's transmission speed and the range of the tensile force. Based on the model constraints, the finite element model is analyzed to simulate the deformation data of the copper wire under several drawing operations. Each drawing operation corresponds to a different drawing operation parameter. The deformation data includes the cross-sectional deformation data and length deformation data of the copper wire during the drawing process.

[0032] As discussed above, copper wire exhibits different drawing deformation states depending on its surface microstructure, three-dimensional shape and size, and mechanical properties. To accurately and comprehensively characterize the deformation during copper wire drawing, numerical simulations are performed on the aforementioned dataset to establish a finite element model of plastic deformation in the copper wire drawing process. Then, based on the allowable range of transmission speed and tensile force applied to the copper wire by the drawing mechanism during the drawing process, model constraints are generated. These constraints may include, but are not limited to, the numerical ranges of transmission speed and tensile force applied to the finite element model. Combining these constraints with the finite element model, cross-sectional deformation data (such as cross-sectional area change data and cross-sectional shape change data) and length deformation data of the copper wire are simulated under several drawing operations, providing a basis for subsequently determining the optimal drawing operation parameters for the copper wire.

[0033] In another embodiment, determining the optimal wire drawing operation parameters based on deformation data includes: Based on the deformation data corresponding to several wire drawing operations, determine the deformation data that is closest to the desired deformation state; wherein, the desired deformation state includes the desired cross-sectional deformation and the desired length deformation within the dimensional tolerance range. The optimal wire drawing operation parameters are determined by the wire drawing passes and the diameter reduction ratio of each pass corresponding to the deformation data that best approximates the desired deformation state.

[0034] It is understandable that a number of wire drawing operations can correspond to a number of copper wire deformations. In actual operation, only copper wires that meet the preset cross-sectional deformation and length deformation conditions can be applied to photovoltaic welding strip scenarios. To ensure that the copper wires obtained from the actual wire drawing operations can meet the material requirements of photovoltaic welding strips, the deformation data corresponding to each of the several wire drawing operations are compared with the expected cross-sectional deformation and expected length deformation to determine the deformation data that is closest to the expected deformation state. Then, the wire drawing passes and the diameter of each pass corresponding to the deformation data that is closest to the expected deformation state are reduced by a certain percentage to determine the optimal wire drawing operation parameters, providing a basis for subsequent actual control of the wire drawing mechanism.

[0035] In another embodiment, the working mode of the wire drawing mechanism is set according to the optimal wire drawing operation parameters, and multi-pass continuous wire drawing of the copper wire is performed, including: Based on the optimal wire drawing operation parameters, determine the working mode corresponding to each wire drawing pass of the wire drawing mechanism; wherein, the working mode includes the traction line speed, tensile force magnitude and duration of each pass applied to the copper wire by the wire drawing mechanism in each wire drawing pass; Based on the working mode, a sequence of control commands is generated for the wire drawing mechanism to execute multiple continuous wire drawing operations on the copper wire.

[0036] Specifically, based on the optimal wire drawing operation parameters, the working mode corresponding to each wire drawing pass of the wire drawing mechanism is determined, and the traction speed, tensile force, and duration of each pass are clearly defined. Furthermore, based on the above working mode, a control command sequence for the wire drawing mechanism is generated. This allows for accurate control of the copper wire transmission and stretching in each pass within the wire drawing mechanism, thereby performing multi-pass continuous wire drawing and ensuring the accuracy of multi-pass wire drawing operations.

[0037] In another embodiment, a sequence of control commands for the wire drawing mechanism is generated according to the operating mode to perform multi-pass continuous wire drawing of the copper wire, including: Based on the magnitude and duration of the tensile force applied to the copper wire in each drawing pass, the operating status of the traction wheel group and tension control device of the drawing mechanism during each drawing pass is determined. Based on the operating status, a sequence of control commands is generated for the traction wheel assembly and the tension control device, so that the traction wheel assembly and the tension control device can work together to perform multiple continuous wire drawing operations on the copper wire.

[0038] In practice, copper wire drawing mainly involves applying tension to the copper wire during its transmission at a corresponding speed, thereby elongating and thinning the wire. To achieve this, the drawing mechanism primarily includes a traction wheel assembly and a tension control device. The traction wheel assembly is used to transmit the copper wire at a corresponding speed, while the tension control device applies tension to the wire. To ensure precise wire drawing through the coordinated operation of the traction wheel assembly and the tension control device, the operating status of these components during each drawing pass is determined based on the magnitude and duration of the tensile force applied to the wire. This generates a sequence of control commands for the traction wheel assembly and the tension control device, enabling them to perform multiple consecutive wire drawing passes.

[0039] In another embodiment, the above method may further include a feedforward compensation step: Within each control cycle, the last sampling time of that control cycle is used. Based on historical transmission speed deviations and current tension fluctuation deviations, the future [number]th [number] [unit] is predicted. The instantaneous transmission speed deviation after each sampling period is used as the feedforward compensation amount corresponding to the control moment of the current control cycle; where... The sampling period is This is the time interval from the last sampling moment in the current control cycle to the control moment within that cycle; take... That is, not less than The smallest integer, in the future... The instantaneous transmission speed deviation after each sampling period is used as... Approximate predicted value at time; The prediction of the future The instantaneous transmission speed deviation after one sampling period includes the following steps: Step A1: Based on the last sampling time and before Transmission speed deviation at each sampling time Calculate the weighted memory cumulative amount using the following formula. : ; in, This refers to the last sampling moment within the current control cycle, expressed in seconds. The sampling period, measured in seconds, is determined by the sampling frequency of the control system. The serial numbers of the historical sampling points, from 0 to... , Corresponding to the last sampling time, Corresponding to the previous sampling time, and so on; The length of the history window, taken as a positive integer, ranging from 50 to 100; The memory decay factor is dimensionless and has a range of values. This is used to control the rate at which historical data is forgotten, and is obtained by optimizing historical prediction errors through offline grid search. For the first The instantaneous transmission speed deviation at each historical sampling moment, where when hour, Measured directly by a speed sensor, in millimeters per second; This is the weighted cumulative memory, measured in millimeters per second, used to quantify the long-term trend of historical velocity deviation. Step A2: Based on the actual tension of the copper wire at the last sampling time. The actual tension at the previous sampling time The difference, and the axial stiffness of the copper wire. The instantaneous transmission speed deviation estimated by the physical model is calculated using the following formula. : ; in, and These are the actual tensions of the copper wire at the last sampling moment and the previous sampling moment, respectively, in Newtons, collected by a tension sensor. This represents the axial stiffness of the copper wire, measured in Newtons per millimeter. The instantaneous transmission speed deviation estimated by the physical model, in millimeters per second; Step A3: Accumulate the weighted memory amount Compared with the physical model estimate By fusing according to the formula, we obtain the future number. Predicted instantaneous transmission speed deviation after one sampling period , will the As the feedforward compensation amount corresponding to the control moment within the current control cycle: ; in, For the future Predicted instantaneous transmission speed deviation after one sampling period; for The corresponding normalization coefficient, in millimeters per second, is 1% to 10% of the target linear velocity or twice the standard deviation of the historical transmission speed (whichever is greater). This is a smoothing parameter, dimensionless, taking values ​​of positive real numbers, with a typical value of [value missing]. This is used to control the steepness of the fusion curve, and can be set based on experience or determined through offline optimization; As an index weighting factor, when When the value is large, the fusion weights are automatically adjusted.

[0040] The physical meaning of this formula is: when When it is positive and very large, Predicted value Approaching the physical model estimate ;when When it is negative and its absolute value is very large, The predicted value approaches the weighted memory accumulation. ;when hour, The predicted value is the arithmetic mean of the physical model estimate and the accumulated memory. Accordingly, during the control moment within the current control cycle, controlling the first group of PID controllers to adjust the speed of the traction wheel group of the wire drawing mechanism according to the conveying speed deviation includes: The result obtained in step A3 As a feedforward compensation quantity, at the control moment within the current control cycle, the feedforward compensation quantity is added to the output calculated by the first group of PID controllers based on the transmission speed deviation at the last sampling moment within the current control cycle (i.e., feedforward plus feedback), and the sum is used as the target speed command for the traction wheel set, and the traction wheel set is controlled to run according to the target speed command.

[0041] The above technical solution, by combining historical trends and physical models, predicts future speed deviations in advance and generates feedforward compensation in an adaptive fusion manner, thereby reducing dynamic errors caused by feedback delay, improving the response speed and stability of the wire drawing process, and reducing the risk of wire breakage.

[0042] In another embodiment, the second set of PID controllers adjusts the tension control device of the wire drawing mechanism according to the tension fluctuation deviation, which can be implemented as follows: Step B1, the last sampling time in each control cycle Obtain the tension fluctuation deviation at that moment. and its rate of change ;in, This represents the tension fluctuation deviation at the previous sampling time. Step B2: Based on the absolute value of the tension fluctuation deviation at the last sampling time... The nonlinear correction coefficient of the proportional gain is calculated using the following formula. : ; in, To correct the intensity coefficient, dimensionless, with a range of values. The preferred value is 0.5 to 0.8, which can be adjusted through simulation or experimentation. This serves as a reference threshold for tension fluctuation deviation, measured in Newtons, with a preferred value of 5% to 10% of the target tension. For the hyperbolic tangent function, map the absolute value of the deviation to , making In 1 to The variation between them. In this formula, The larger, The closer to 1, The larger the value, the higher the dynamic proportional gain and the faster the response; Step B3: Based on the rate of change of tension fluctuation deviation at the last sampling time. The nonlinear correction coefficient for the integral gain is calculated using the following formula. : ; in, The attenuation coefficient, in seconds, was determined experimentally. In specific implementation, it is possible to first... Set the value to 0 and observe the step response. If overshoot caused by integral saturation occurs, gradually increase the value. The overshoot continues until the requirement is met, preferably between 0.05 and 0.5 seconds. In this formula, The larger, The smaller the value, the lower the dynamic integral gain, and the weaker the integral effect, thus suppressing integral saturation; Step B4: Adjust the nonlinear correction coefficient of the proportional gain. The base proportional gain of the second group of PID controllers The product of these two values ​​serves as the dynamic proportional gain of the second set of PID controllers at the control moment within the current control cycle. The nonlinear correction coefficient of the integral gain Base integral gain of the second group of PID controllers The product of these two values ​​serves as the dynamic integral gain of the second set of PID controllers at the control moment within the current control cycle. ; Step B5: During the control time of the second group of PID controllers within the current control cycle, the dynamic proportional gain is used. and According to the tension fluctuation deviation Calculate the output control quantity, and adjust the tension of the tension control device accordingly.

[0043] To improve the dynamic quality of tension control, the second PID controller in the above technical solution employs a dynamic response enhancement method based on nonlinear gain. Without altering the basic structure of the PID controller, the proportional and integral gains in the controller are dynamically adjusted according to real-time operating conditions.

[0044] Specifically, the output control quantity (i.e., the tension correction quantity) of a standard PID controller consists of three terms: a proportional term (proportional to the current deviation), an integral term (proportional to the cumulative deviation), and a derivative term (proportional to the rate of change of the deviation), and its mathematical expression is: ; in, These are proportional gain, integral gain, and derivative gain, respectively. This represents the tension fluctuation deviation at the current sampling moment. This formula is the standard form in control theory, and its physical meaning is: the proportional term provides an immediate response to the current deviation, the integral term eliminates steady-state error, and the derivative term suppresses the trend of deviation change.

[0045] The above technical solution will have a fixed proportional gain. and integral gain Replace with a time-varying dynamic proportional gain and And differential gain It can remain fixed (because the derivative term is sensitive to noise and is usually not dynamically adjusted). The output of the replaced controller is: ; Among them, dynamic proportional gain and Calculate in real time according to steps B2 to B4: First, based on the absolute value of the current tension fluctuation deviation... Calculate the proportional gain correction factor According to the rate of change of deviation Calculate the integral gain correction factor Then these correction coefficients are compared with the pre-obtained base gain. Multiply to obtain the dynamic proportional gain. , .

[0046] In this way, the structure of the standard PID formula is completely preserved, only the fixed gain is replaced with a dynamic proportional gain that changes in real time, thus achieving adaptive adjustment of tension fluctuations without changing the basic working principle of the controller.

[0047] The dynamic proportional gain method described above can automatically adjust PID parameters according to real-time operating conditions. It increases the proportional gain to accelerate response when deviations are large, and reduces the integral gain to avoid overshoot and integral saturation when deviations change drastically. Compared to fixed-gain PID, this improves the dynamic quality and robustness of tension control, making it suitable for the frequent tension fluctuations that occur during wire drawing.

[0048] Additional explanation: In the second group of PID controllers, the derivative gain... Keep it constant and do not make dynamic adjustments to avoid excessive amplification of measurement noise.

[0049] Base gain The tuning steps are illustrated below: Initial parameters were obtained using the Ziegler-Nichols critical proportional method under no-load (no copper wire) or steady-state operation conditions of the wire drawing mechanism; under loaded conditions, the response curve was observed with the target tension as a step input, and fine adjustments were made. Ensure overshoot is less than 5% and settling time is less than 0.5 seconds; fix After that, take The initial value is , and then with The system's step response was observed by gradually increasing the step size. When the overshoot was less than 5%, the settling time was less than 0.5 seconds, and the response curve showed no sustained high-frequency oscillations, it was considered... Tuning complete. If noise amplification occurs, reduce the noise level appropriately. .final The typical range of values ​​is to .

[0050] Corresponding to the methods provided in any of the foregoing embodiments, this invention also provides a dynamic compensation system for multi-pass wire drawing speed and tension of photovoltaic solder ribbon copper wire based on closed-loop feedback, comprising: The model processing module is used to establish a finite element model of the copper wire drawing process, thereby simulating the deformation data of the copper wire under several drawing operations; based on the deformation data, the optimal drawing operation parameters are determined. The wire drawing module is used to set the working mode of the wire drawing mechanism according to the optimal wire drawing operation parameters, and to perform multiple continuous wire drawing of copper wire. The control processing module is used to perform the following steps in each control cycle: At each sampling moment within the current control cycle, the copper wire traction line speed is acquired, and the transmission speed deviation at that sampling moment is determined based on the difference between the copper wire traction line speed and the target line speed; at each sampling moment within the current control cycle, the actual tension of the copper wire is acquired, and the tension fluctuation deviation at that sampling moment is determined based on the difference between the actual tension of the copper wire and the target tension. At a control moment within the current control cycle, the first set of PID controllers adjusts the speed of the traction wheel group of the wire drawing mechanism according to the conveying speed deviation; the second set of PID controllers adjusts the tension control device tension of the wire drawing mechanism according to the tension fluctuation deviation, thereby correcting the processing state of the copper wire; wherein, the control moment is located within the current control cycle and is later than the last sampling moment in the cycle.

[0051] In one embodiment, a feedforward compensation module is further included, for: Within each control cycle, the last sampling time of that control cycle is used. Based on historical transmission speed deviations and current tension fluctuation deviations, the future [number]th [number] [unit] is predicted. The instantaneous transmission speed deviation after each sampling period is used as the feedforward compensation amount corresponding to the control moment of the current control cycle; where... The sampling period is This is the time interval from the last sampling moment in the current control cycle to the control moment within that cycle; take... That is, not less than The smallest integer, in the future... The instantaneous transmission speed deviation after each sampling period is used as... Approximate predicted value at time; The prediction of the future The instantaneous transmission speed deviation after one sampling period includes the following steps: Step A1: Based on the last sampling time and before Transmission speed deviation at each sampling time Calculate the weighted memory cumulative amount using the following formula. : ; in, This is the last sampling moment within the current control cycle; The sampling period; The serial numbers of the historical sampling points, from 0 to... , Corresponding to the last sampling time, Corresponding to the previous sampling time, and so on; The length of the history window, taken as a positive integer, ranging from 50 to 100; It is the memory decay factor; For the first The instantaneous transmission speed deviation at each historical sampling moment, where when hour, Measured directly by a speed sensor; This is the weighted cumulative memory amount; Step A2: Based on the actual tension of the copper wire at the last sampling time. The actual tension at the previous sampling time The difference, and the axial stiffness of the copper wire. The instantaneous transmission speed deviation estimated by the physical model is calculated using the following formula. : ; in, and These are the actual tensions of the copper wire at the last sampling moment and the previous sampling moment, respectively. The axial stiffness of the copper wire; The deviation of the instantaneous transmission speed estimated by the physical model; Step A3: Accumulate the weighted memory amount Compared with the physical model estimate By fusing according to the formula, we obtain the future number. Predicted instantaneous transmission speed deviation after one sampling period , will the As the feedforward compensation amount corresponding to the control moment within the current control cycle: ; in, For the future Predicted instantaneous transmission speed deviation after one sampling period; for The corresponding normalization coefficient; For smoothing parameters; As an index weighting factor, when Automatically adjust fusion weights when the value is large; Accordingly, during the control moment within the current control cycle, controlling the first group of PID controllers to adjust the speed of the traction wheel group of the wire drawing mechanism according to the conveying speed deviation includes: The result obtained in step A3 As a feedforward compensation quantity, at the control moment within the current control cycle, the feedforward compensation quantity is added to the output calculated by the first group of PID controllers based on the transmission speed deviation at the last sampling moment within the current control cycle. The sum is used as the target speed command for the traction wheel set, and the traction wheel set is controlled to run according to the target speed command.

[0052] In one embodiment, the second set of PID controllers adjusts the tension control device tension of the wire drawing mechanism according to the tension fluctuation deviation, including: Step B1, the last sampling time in each control cycle Obtain the tension fluctuation deviation at that moment. and its rate of change in, This represents the tension fluctuation deviation at the previous sampling time. Step B2: Based on the absolute value of the tension fluctuation deviation at the last sampling time... The nonlinear correction coefficient of the proportional gain is calculated using the following formula. : ; in, To correct the strength coefficient; This serves as the reference threshold for tension fluctuation deviation; It is the hyperbolic tangent function; Step B3: Based on the rate of change of tension fluctuation deviation at the last sampling time. The nonlinear correction coefficient for the integral gain is calculated using the following formula. : in, This is the attenuation coefficient, expressed in seconds. Step B4: Adjust the nonlinear correction coefficient of the proportional gain. The base proportional gain of the second group of PID controllers The product of these two values ​​serves as the dynamic proportional gain of the second set of PID controllers at the control moment within the current control cycle. The nonlinear correction coefficient of the integral gain Base integral gain of the second group of PID controllers The product of these two values ​​serves as the dynamic integral gain of the second set of PID controllers at the control moment within the current control cycle. ; Step B5: During the control time of the second group of PID controllers within the current control cycle, the dynamic proportional gain is used. and According to the tension fluctuation deviation Calculate the output control quantity, and adjust the tension of the tension control device accordingly.

[0053] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. This disclosure is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this disclosure is limited only by the appended claims. Thus, if these modifications and variations of the invention fall within the scope of the claims of the invention and their equivalents, the invention is also intended to include these modifications and variations.

Claims

1. A method for dynamic compensation of multi-pass drawing speed and tension of copper wire for photovoltaic welding ribbon based on closed-loop feedback, characterized in that, include: A finite element model of the copper wire drawing process was established to simulate the deformation data of the copper wire under several drawing operations. Based on the deformation data, determine the optimal wire drawing operation parameters; Based on the optimal wire drawing operation parameters, the working mode of the wire drawing mechanism is set to perform multiple continuous wire drawing operations on the copper wire; and within each control cycle, the following steps are performed: At each sampling moment within the current control cycle, the copper wire traction line speed is acquired, and the transmission speed deviation at that sampling moment is determined based on the difference between the copper wire traction line speed and the target line speed; at each sampling moment within the current control cycle, the actual tension of the copper wire is acquired, and the tension fluctuation deviation at that sampling moment is determined based on the difference between the actual tension of the copper wire and the target tension. At the control moment within the current control cycle, the first set of PID controllers adjusts the speed of the traction wheel group of the wire drawing mechanism according to the conveying speed deviation; the second set of PID controllers adjusts the tension control device tension of the wire drawing mechanism according to the tension fluctuation deviation, thereby correcting the processing state of the copper wire; wherein, the control moment is within the current control cycle and is later than the last sampling moment in the cycle; It also includes a feedforward compensation step: Within each control cycle, the last sampling time of that control cycle is used. Based on historical transmission speed deviations and current tension fluctuation deviations, the future [number]th [number] [unit] is predicted. The instantaneous transmission speed deviation after each sampling period is used as the feedforward compensation amount corresponding to the control moment of the current control cycle; where... The sampling period is This is the time interval from the last sampling moment in the current control cycle to the control moment within that cycle; take... That is, not less than The smallest integer, in the future... The instantaneous transmission speed deviation after each sampling period is used as... Approximate predicted value at time; The prediction of the future The instantaneous transmission speed deviation after one sampling period includes the following steps: Step A1: Based on the last sampling time and before Transmission speed deviation at each sampling time Calculate the weighted memory cumulative amount using the following formula. : ； in, This is the last sampling moment within the current control cycle; The sampling period; The serial numbers of the historical sampling points, from 0 to... , Corresponding to the last sampling time, Corresponding to the previous sampling time, and so on; The length of the history window, taken as a positive integer, ranging from 50 to 100; It is the memory decay factor; For the first The instantaneous transmission speed deviation at each historical sampling moment, where when hour, Measured directly by a speed sensor; This is the weighted cumulative memory amount; Step A2: Based on the actual tension of the copper wire at the last sampling time. The actual tension at the previous sampling time The difference, and the axial stiffness of the copper wire. The instantaneous transmission speed deviation estimated by the physical model is calculated using the following formula. : ； in, and These are the actual tensions of the copper wire at the last sampling moment and the previous sampling moment, respectively. The axial stiffness of the copper wire; The deviation of the instantaneous transmission speed estimated by the physical model; Step A3: Accumulate the weighted memory amount Compared with the physical model estimate By fusing according to the formula, we obtain the future number. Predicted instantaneous transmission speed deviation after one sampling period , will the As the feedforward compensation amount corresponding to the control moment within the current control cycle: ； in, For the future Predicted instantaneous transmission speed deviation after one sampling period; for The corresponding normalization coefficient; For smoothing parameters; As an index weighting factor, when Automatically adjust fusion weights when the value is large; Accordingly, during the control moment within the current control cycle, controlling the first group of PID controllers to adjust the speed of the traction wheel group of the wire drawing mechanism according to the conveying speed deviation includes: The result obtained in step A3 As a feedforward compensation quantity, at the control moment within the current control cycle, the feedforward compensation quantity is added to the output calculated by the first group of PID controllers based on the transmission speed deviation at the last sampling moment within the current control cycle. The sum is used as the target speed command for the traction wheel set, and the traction wheel set is controlled to run according to the target speed command.

2. The method for dynamic compensation of multi-pass drawing speed and tension of photovoltaic welding strip copper wire based on closed-loop feedback as described in claim 1, characterized in that, Before establishing the finite element model of the copper wire drawing process, the following steps are included: Images of the copper wire drawing process and material property data of the copper wire are collected for each of several drawing passes; wherein, the drawing process images include three-dimensional images of the copper wire during the drawing process; the material property data include the elastic modulus, yield strength, and elongation mechanical property data of the copper wire during the drawing process; Identify the surface microstructure data and three-dimensional shape and size data of the copper wire during the drawing process from the three-dimensional image; Based on the time information during the wire drawing process, the mechanical property data, the surface microstructure data, and the three-dimensional shape and size data are timestamped and formatted to obtain a data set.

3. The method for dynamic compensation of multi-pass drawing speed and tension of photovoltaic welding strip copper wire based on closed-loop feedback as described in claim 2, characterized in that, The establishment of a finite element model of the copper wire drawing process is used to simulate the deformation data of the copper wire under several drawing operations, including: Numerical simulations were performed based on the aforementioned dataset to establish a finite element model of plastic deformation during the copper wire drawing process. Based on the working parameters of the wire drawing mechanism, model constraints are set; wherein, the working parameters include the range of the wire drawing mechanism's transmission speed and the range of the tensile force. Based on the model constraints, the finite element model is analyzed to simulate the deformation data of the copper wire under several drawing operations; wherein, the several drawing operations correspond one-to-one with several drawing operation parameters; the deformation data includes the cross-sectional deformation data and length deformation data of the copper wire during drawing.

4. The method for dynamic compensation of multi-pass drawing speed and tension of photovoltaic welding strip copper wire based on closed-loop feedback as described in claim 3, characterized in that, The step of determining the optimal wire drawing operation parameters based on the deformation data includes: Based on the deformation data corresponding to each of the several wire drawing operations, the deformation data closest to the desired deformation state is determined; wherein, the desired deformation state includes the desired cross-sectional deformation and the desired length deformation within the dimensional tolerance range; The optimal wire drawing operation parameters are determined by the wire drawing passes and the reduction ratio of the diameter of each pass corresponding to the deformation data that is closest to the desired deformation state.

5. The method for dynamic compensation of multi-pass drawing speed and tension of photovoltaic welding strip copper wire based on closed-loop feedback as described in claim 1, characterized in that, The step of setting the working mode of the wire drawing mechanism according to the optimal wire drawing operation parameters and performing multi-pass continuous wire drawing of copper wire includes: Based on the optimal wire drawing operation parameters, the working mode corresponding to each wire drawing pass of the wire drawing mechanism is determined; wherein, the working mode includes the traction line speed, tensile force magnitude and duration of each wire drawing pass applied to the copper wire by the wire drawing mechanism. Based on the operating mode, a sequence of control commands is generated for the wire drawing mechanism to perform multiple continuous wire drawing operations on the copper wire.

6. The method for dynamic compensation of multi-pass drawing speed and tension of photovoltaic welding strip copper wire based on closed-loop feedback as described in claim 1, characterized in that, The second set of PID controllers adjusts the tension control device of the wire drawing mechanism according to the tension fluctuation deviation, including: Step B1, the last sampling time in each control cycle Obtain the tension fluctuation deviation at that moment. and its rate of change: in, This represents the tension fluctuation deviation at the previous sampling time. Step B2: Based on the absolute value of the tension fluctuation deviation at the last sampling time... The nonlinear correction coefficient of the proportional gain is calculated using the following formula. : ； in, To correct the strength coefficient; This serves as the reference threshold for tension fluctuation deviation; It is the hyperbolic tangent function; Step B3: Based on the rate of change of tension fluctuation deviation at the last sampling time. The nonlinear correction coefficient for the integral gain is calculated using the following formula. : in, This is the attenuation coefficient, expressed in seconds. Step B4: Adjust the nonlinear correction coefficient of the proportional gain. The base proportional gain of the second group of PID controllers The product of these two values ​​serves as the dynamic proportional gain of the second set of PID controllers at the control moment within the current control cycle. The nonlinear correction coefficient of the integral gain Base integral gain of the second group of PID controllers The product of these two values ​​serves as the dynamic integral gain of the second set of PID controllers at the control moment within the current control cycle. ; Step B5: During the control time of the second group of PID controllers within the current control cycle, the dynamic proportional gain is used. and According to the tension fluctuation deviation Calculate the output control quantity, and adjust the tension of the tension control device accordingly.

7. A dynamic compensation system for multi-pass drawing speed and tension of photovoltaic welding ribbon copper wire based on closed-loop feedback, characterized in that, include: The model processing module is used to build a finite element model of the copper wire drawing process, thereby simulating the deformation data of the copper wire under several drawing operations. Based on the deformation data, determine the optimal wire drawing operation parameters; The wire drawing module is used to set the working mode of the wire drawing mechanism according to the optimal wire drawing operation parameters, and to perform multiple continuous wire drawing of copper wire. The control processing module is used to perform the following steps in each control cycle: At each sampling moment within the current control cycle, the copper wire traction line speed is acquired, and the transmission speed deviation at that sampling moment is determined based on the difference between the copper wire traction line speed and the target line speed; at each sampling moment within the current control cycle, the actual tension of the copper wire is acquired, and the tension fluctuation deviation at that sampling moment is determined based on the difference between the actual tension of the copper wire and the target tension. At the control moment within the current control cycle, the first set of PID controllers adjusts the speed of the traction wheel group of the wire drawing mechanism according to the conveying speed deviation; the second set of PID controllers adjusts the tension control device tension of the wire drawing mechanism according to the tension fluctuation deviation, thereby correcting the processing state of the copper wire; wherein, the control moment is within the current control cycle and is later than the last sampling moment in the cycle; It also includes a feedforward compensation module, used for: Within each control cycle, the last sampling time of that control cycle is used. Based on historical transmission speed deviations and current tension fluctuation deviations, the future [number]th [number] [unit] is predicted. The instantaneous transmission speed deviation after each sampling period is used as the feedforward compensation amount corresponding to the control moment of the current control cycle; where... The sampling period is This is the time interval from the last sampling moment in the current control cycle to the control moment within that cycle; take... That is, not less than The smallest integer, in the future... The instantaneous transmission speed deviation after each sampling period is used as... Approximate predicted value at time; The prediction of the future The instantaneous transmission speed deviation after one sampling period includes the following steps: Step A1: Based on the last sampling time and before Transmission speed deviation at each sampling time Calculate the weighted memory cumulative amount using the following formula. : ； in, This is the last sampling moment within the current control cycle; The sampling period; The serial numbers of the historical sampling points, from 0 to... , Corresponding to the last sampling time, Corresponding to the previous sampling time, and so on; The length of the history window, taken as a positive integer, ranging from 50 to 100; It is the memory decay factor; For the first The instantaneous transmission speed deviation at each historical sampling moment, where when hour, Measured directly by a speed sensor; This is the weighted cumulative memory amount; Step A2: Based on the actual tension of the copper wire at the last sampling time. The actual tension at the previous sampling time The difference, and the axial stiffness of the copper wire. The instantaneous transmission speed deviation estimated by the physical model is calculated using the following formula. : ； in, and These are the actual tensions of the copper wire at the last sampling moment and the previous sampling moment, respectively. The axial stiffness of the copper wire; The deviation of the instantaneous transmission speed estimated by the physical model; Step A3: Accumulate the weighted memory amount Compared with the physical model estimate By fusing according to the formula, we obtain the future number. Predicted instantaneous transmission speed deviation after one sampling period , will the As the feedforward compensation amount corresponding to the control moment within the current control cycle: ； in, For the future Predicted instantaneous transmission speed deviation after one sampling period; for The corresponding normalization coefficient; For smoothing parameters; As an index weighting factor, when Automatically adjust fusion weights when the value is large; Accordingly, during the control moment within the current control cycle, controlling the first group of PID controllers to adjust the speed of the traction wheel group of the wire drawing mechanism according to the conveying speed deviation includes: The result obtained in step A3 As a feedforward compensation quantity, at the control moment within the current control cycle, the feedforward compensation quantity is added to the output calculated by the first group of PID controllers based on the transmission speed deviation at the last sampling moment within the current control cycle. The sum is used as the target speed command for the traction wheel set, and the traction wheel set is controlled to run according to the target speed command.

8. The photovoltaic welding strip copper wire multi-pass wire drawing speed and tension dynamic compensation system based on closed-loop feedback as described in claim 7, characterized in that, The second set of PID controllers adjusts the tension control device of the wire drawing mechanism according to the tension fluctuation deviation, including: Step B1, the last sampling time in each control cycle Obtain the tension fluctuation deviation at that moment. and its rate of change: in, This represents the tension fluctuation deviation at the previous sampling time. Step B2: Based on the absolute value of the tension fluctuation deviation at the last sampling time... The nonlinear correction coefficient of the proportional gain is calculated using the following formula. : ； in, To correct the strength coefficient; This serves as the reference threshold for tension fluctuation deviation; It is the hyperbolic tangent function; Step B3: Based on the rate of change of tension fluctuation deviation at the last sampling time. The nonlinear correction coefficient for the integral gain is calculated using the following formula. : in, This is the attenuation coefficient, expressed in seconds. Step B4: Adjust the nonlinear correction coefficient of the proportional gain. The base proportional gain of the second group of PID controllers The product of these two values ​​serves as the dynamic proportional gain of the second set of PID controllers at the control moment within the current control cycle. The nonlinear correction coefficient of the integral gain Base integral gain of the second group of PID controllers The product of these two values ​​serves as the dynamic integral gain of the second set of PID controllers at the control moment within the current control cycle. ; Step B5: During the control time of the second group of PID controllers within the current control cycle, the dynamic proportional gain is used. and According to the tension fluctuation deviation Calculate the output control quantity, and adjust the tension of the tension control device accordingly.

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