Positioning cold stamping process and its positioning cold stamping system implemented on a metal sheet

Abstract

This invention discloses a positioning cold-stamping process and system for metal sheets. Through a two-stage positioning and offset calculation, a photoelectric sensor first detects black and white stripes for coarse positioning. Then, a laser sensor detects a notch, measures the actual duration of the laser signal, and calculates the current offset. Based on the current offset, an adaptive predictive feedforward control algorithm, including trend prediction and compensation calculation, is run by a controller. Adjustment commands are sent to the servo motor system driving the transfer film, adjusting its relative position in real time with a response time of no more than 10 milliseconds. The advantages of this invention are: it effectively overcomes the challenges of the high rigidity and strong reflectivity of metal sheets, achieving high-precision positioning, possessing adaptive capabilities and a complete process closed loop, and meeting the requirements of high-end metal products for cold-stamping positioning accuracy, production efficiency, and multi-material compatibility.

Description

Technical Field

[0001] This invention relates to the field of cold stamping technology, and more particularly to a positioning cold stamping process for metal sheets. Background Technology

[0002] Cold foil stamping, as a highly efficient and environmentally friendly surface decoration process, involves applying an electroplated aluminum film (transfer film) with a metallic texture to the surface of a substrate under pressure at room temperature. It is widely used in packaging, printing, and other fields. However, traditional cold foil stamping processes face significant challenges when the substrate is a metal sheet.

[0003] First, metal sheets possess physical properties such as high rigidity, smooth surface, and strong reflectivity. During high-speed conveying, metal sheets are prone to slight warping or lateral shifts due to factors such as uneven thickness and changes in roller pressure, leading to unstable conveying posture. This instability makes it difficult for traditional positioning methods to ensure precise alignment between the pattern on the transfer film and the predetermined position on the metal sheet.

[0004] Secondly, existing positioning technologies mainly rely on setting color marks on the edges of materials and using photoelectric sensors for detection. For example, a metal printing cold foil lamination machine disclosed in prior patent CN118650971A achieves a certain degree of positioning by setting black and white stripes on the edges of the transfer film and the substrate and using photoelectric sensors for detection. However, this method has the following defects: (1) It is sensitive to interference such as strong reflection and surface scratches of metal sheets, which can easily lead to false signal triggering or missed detection, resulting in unstable positioning accuracy; (2) Its control logic is mainly based on fixed equipment structure and parameters, without considering the differences in thickness, hardness and reflectivity of metal sheets of different batches and different materials (such as iron, aluminum, stainless steel and copper), resulting in poor process versatility; (3) It lacks active control of the conveying posture of metal sheets and online quality feedback loop of processing results, and cannot achieve continuous optimization of process accuracy and rapid response to abnormal situations.

[0005] Therefore, existing technologies cannot meet the requirements of high-end metal products for cold hot stamping positioning accuracy (usually requiring better than ±0.2mm), production efficiency, and multi-material compatibility. There is an urgent need for a high-precision positioning cold hot stamping process that can overcome the challenges of the physical properties of metal sheets, has self-adaptive capabilities, and a complete process closed loop. Summary of the Invention

[0006] The purpose of this invention is to provide a control method that can intelligently adapt to the characteristics of different metal sheets, achieve low cost, high control precision, and fundamentally solve the problem of metal sheet positioning.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: a positioning cold-stamping process on metal sheets, comprising the following steps:

[0008] a) Preparation steps: On the transfer film and the metal sheet used as the printing substrate, black and white stripes for preliminary positioning are made (by fiber laser engraving and surface coated with wear-resistant ceramic coating), and detection notches for precise positioning are made (by precision wire cutting). The edge roughness Ra of the black and white stripes is ≤0.1mm, and the edge straightness of the detection notches is ≤0.1mm.

[0009] b) Conveying and Attitude Stabilization Steps: During the conveying of the metal sheet, its conveying attitude is actively controlled and the lateral position of the metal sheet is constrained through a guiding mechanism (specifically a rolling guiding mechanism) with a lateral clearance of no more than 0.05 mm and a pressure compensation mechanism (pneumatic automatic clearance compensation component); pressure compensation is implemented through segmented pressure rollers, and the pressure compensation mechanism is based on the formula... The pressure P of the pressure roller is dynamically set to prevent sheet warping or plastic deformation.

[0010] Where k is the pressure reference coefficient, d is the thickness of the metal sheet (collected in real time by a thickness sensor), and h is the hardness correction coefficient of the metal sheet (set according to HV classification).

[0011] c) Two-stage positioning and offset calculation steps: First, use a photoelectric sensor to detect the black and white stripes to complete coarse positioning.

[0012] Then, a laser sensor with a polarized laser and a narrowband filter is used to detect the detection gap, measure the actual duration t of the laser signal, and apply the offset distance formula. Calculate the current offset.

[0013] Where L is the length of the detection gap and v is the conveying speed;

[0014] d) Trend prediction and compensation calculation steps: Based on the current offset Δm, the adaptive predictive feedforward control algorithm is run by the controller, including:

[0015] i. Trend Forecasting: Based on the most recent N historical offset data (N=5~15, N=5-10 when production speed is 30-50m / min, N=10-15 when production speed is <30m / min), the predicted offset is calculated using a weighted moving average algorithm. ,in Let be the weighting coefficient, satisfying ;

[0016] ii. Compensation Calculation: According to the formula Calculate the total compensation A, where Kp is the proportional gain and Kf is the feedforward gain;

[0017] e) Dynamic adjustment step: Send adjustment commands to the servo motor system driving the transfer film to adjust its relative position in real time with a response time of no more than 10 milliseconds;

[0018] f) Lamination step: Press and laminate the dynamically compensated and precisely aligned transfer film and metal sheet together;

[0019] g) Quality inspection and feedback steps: Online detection of the alignment accuracy of the composite product. When the accuracy continuously exceeds the preset tolerance, the control parameters are adjusted in reverse or an alarm is triggered.

[0020] Preferably, the pressure reference coefficient k is determined based on the material of the metal sheet;

[0021] The hardness correction factor h is determined based on the Vickers hardness HV value: when HV≤100, h=1.0-1.2; when HV=100-200, h=1.5-1.8; when HV≥200, h=1.8-2.0.

[0022] Preferably, in the offset calculation step c), the offset distance formula is... The applicable conditions are ,when If the measurement is abnormal (e.g., the marker is obscured), the measurement data is discarded.

[0023] Preferably, in the trend prediction step i), before performing the weighted moving average calculation, abnormal offset data caused by sensor interference is filtered out by using a 3-standard-deviation threshold method. The threshold is set to 3 standard deviations to eliminate abnormal offset data caused by sensor interference (such as reflection, dust) and ensure the purity of the input data.

[0024] Preferably, the proportional gain Kp and feedforward gain Kf are dynamically adjusted based on the thickness d and hardness h parameters of the metal sheet, either by looking up a preset table or by calculation through a fuzzy logic controller. The value range of Kp is 0.6-1.2, and the value range of Kf is 0.3-0.7.

[0025] Preferably, the adjustment command in the dynamic adjustment step e) coordinates the speed and torque of the servo motor to maintain the tension fluctuation of the transfer film within ±5% range through a tension closed loop while adjusting the position.

[0026] Preferably, the encoder sampling frequency of the servo motor system is not less than 20kHz, and its controller is equipped with a backlash compensation parameter to compensate for the mechanical backlash of the transmission mechanism.

[0027] A positioning cold stamping system for metal sheets, comprising:

[0028] a) A conveying and attitude stabilization unit, including a guiding mechanism for constraining the lateral position of the metal sheet and a pressure compensation mechanism for compensating for changes in the thickness of the metal sheet;

[0029] b) A dual-stage positioning unit, comprising a photoelectric sensor for detecting black and white stripes and a laser sensor for detecting a detection notch;

[0030] c) A drive unit, including a servo motor system for driving the transfer film;

[0031] d) A controller, electrically connected to the dual-stage positioning unit and the drive unit, which internally stores and executes a program for implementing the positioning cold-stamping process on the metal sheet as described in any of the preceding claims.

[0032] Preferably, the controller is further configured to dynamically adjust its control gain Kp and Kf based on the thickness or hardness parameters of the processed metal sheet by querying a preset lookup table or by calculating through a fuzzy logic controller.

[0033] Preferably, it includes an online quality inspection unit, located downstream of the composite workstation, for detecting the accuracy of the finished product and feeding back data to the controller.

[0034] The beneficial effects of this invention are as follows: By using a dual-stage positioning and offset calculation, combined with an adaptive predictive feedforward control algorithm, the challenges of physical characteristics such as high rigidity and strong reflectivity of metal sheets can be effectively overcome, achieving high-precision positioning (better than ±0.2mm), possessing adaptive capabilities and a complete process closed loop, and meeting the requirements of high-end metal products for cold hot stamping positioning accuracy, production efficiency, and multi-material compatibility. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0036] Figure 1 This is a schematic diagram of the metal sheet positioning and cold ironing system of the present invention.

[0037] Figure 2 yes Figure 1 A magnified schematic diagram of the black and white stripes and the detection notch on the metal sheet at point A.

[0038] Figure 3 This is a schematic diagram of the overall structure of the metal sheet positioning and cold ironing system of the present invention.

[0039] Figure 4 This is a schematic diagram of the anti-reflective detection principle of the laser sensor of the present invention.

[0040] Figure 5These are comparison images of the cold-stamping effect of the metal sheet according to the present invention.

[0041] Figure 6 This is a schematic diagram of the operation of the line quality inspection unit of the present invention.

[0042] Among them: 10 black and white stripes; 20 detection gaps. Detailed Implementation

[0043] Existing metal sheet positioning systems often suffer from instability and insufficient accuracy when handling highly reflective and rigid metal sheets. The root cause lies in the mismatch between the physical properties of the metal sheet and traditional positioning techniques. First, the high rigidity, smooth surface, and strong reflectivity of metal sheets make them prone to instability during high-speed transport. Second, traditional photoelectric sensor positioning methods are sensitive to interference from strong reflections and scratches on the metal surface, easily leading to false triggering or missed detections.

[0044] Positioning instability typically occurs in the following situations: when the thickness of the metal sheet is uneven or the roller pressure changes, slight warping or lateral shifts may occur; when the sensor detects a strong reflective signal, signal saturation or false triggering may occur; when metal sheets of different materials (such as iron, aluminum, stainless steel, and copper) differ in thickness, hardness, and reflectivity, fixed control parameters may not be suitable.

[0045] like Figures 1-4 As shown, the positioning cold stamping system mainly includes a conveying and attitude stabilization unit, a two-stage positioning unit, a drive unit, a controller, and an online quality inspection unit. Specifically, the metal sheet is conveyed through the conveying and attitude stabilization unit, which includes a guiding mechanism and a pressure compensation mechanism; the two-stage positioning unit includes photoelectric sensors and laser sensors, used for coarse positioning and precise positioning, respectively; the drive unit includes a servo motor system for driving the transfer film; the controller is responsible for the coordinated control of the entire system; and the online quality inspection unit is used to detect the accuracy of the finished product and provide data feedback.

[0046] This invention implements a positioning cold hot stamping process on metal sheets, comprising the following steps:

[0047] a) Preparation steps: On the transfer film and the metal sheet used as the substrate, structures for preliminary positioning are made respectively: black and white stripes are formed by engraving with fiber laser and coating with wear-resistant ceramic coating, and detection notches for precise positioning are formed. The detection notches are made by precision wire cutting. The edge roughness Ra of the black and white stripes is ≤0.1mm and the edge straightness of the detection notches is ≤0.1mm.

[0048] b) Conveying and Attitude Stabilization Steps: During the conveying of the metal sheet, its conveying attitude is actively controlled and its lateral position is constrained through a guiding mechanism (specifically a rolling guiding mechanism) with a lateral clearance of no more than 0.05 mm and a pressure compensation mechanism (pneumatic automatic clearance compensation component). Pressure compensation is implemented through segmented pressure rollers, and the pressure compensation mechanism is based on the formula... The pressure of the pressure roller P is dynamically set to avoid warping or plastic deformation of the sheet. The pressure reference coefficient k is determined according to the material of different metal sheets: for example, k=100N / (mm·dimensionless) for iron sheet, k=150N / (mm·dimensionless) for stainless steel sheet, and k=120N / (mm·dimensionless) for copper sheet. The value of the pressure reference coefficient k can be determined based on the mechanical properties of different metal materials, such as elastic modulus and yield strength.

[0049] Where k is the pressure reference coefficient, d is the thickness of the metal sheet (collected in real time by a thickness sensor), and the hardness correction coefficient h is determined according to the Vickers hardness HV value of the metal sheet (set according to HV grading). For example, when HV≤100 (such as soft aluminum), h=1.0-1.2; when HV=100-200 (such as medium-hardness copper alloys and iron sheets), h=1.5-1.8; when HV≥200 (such as stainless steel), h=1.8-2.0. Through this grading setting, it is ensured that metal sheets of different materials can obtain appropriate pressure, ensuring stable conveying posture.

[0050] c) Two-stage positioning and offset calculation steps: First, use a photoelectric sensor to detect the black and white stripes to complete coarse positioning.

[0051] Then, a laser sensor with a polarized laser and a narrowband filter is used to detect the detection gap, measure the actual duration t of the laser signal, and apply the offset distance formula. Calculate the current offset.

[0052] Where L is the length of the detection gap and v is the conveying speed.

[0053] Specifically, the applicable conditions for the offset distance formula are as follows: ,when If the measurement is abnormal (e.g., the marker is obscured), the measurement data is discarded.

[0054] d) Trend prediction and compensation calculation steps: Based on the current offset Δm, the adaptive predictive feedforward control algorithm is run by the controller, including:

[0055] By using a threshold method with a standard deviation of 3, abnormal offset data caused by sensor interference is filtered out. The threshold is set to 3 standard deviations to eliminate abnormal offset data caused by sensor interference (such as reflection and dust) and ensure the purity of input data.

[0056] i. Trend prediction: Based on the most recent N historical offset data, the value of N is limited to 5-15, and the specific value is dynamically adjusted according to the production cycle: N=5-8 for high-speed production (>100 pieces / minute), N=8-12 for medium-speed production (50-100 pieces / minute), and N=12-15 for low-speed production (<50 pieces / minute).

[0057] The predicted offset is calculated using a weighted moving average algorithm. ,in Let be the weighting coefficient, satisfying .

[0058] In one embodiment, the weighting coefficient wi is allocated as follows: the total weight of the five most recent data points accounts for 70%, and the weight of the more recent data points accounts for 30%. Specifically, the allocation is as follows: the most recent data points w1=0.25, w2=0.20, w3=0.15, w4=0.06, w5=0.04; the weight of more recent data points decreases accordingly, ensuring... This weighting ensures sensitivity to recent trends while avoiding overreaction to transient fluctuations.

[0059] ii. Compensation Calculation: According to the formula Calculate the total compensation A, where Kp is the proportional gain and Kf is the feedforward gain.

[0060] In one embodiment, the proportional gain Kp and the feedforward gain Kf are dynamically adjusted based on the thickness d and hardness h parameters of the metal sheet, either by looking up a preset table or by calculation through a fuzzy logic controller. The value range of Kp is 0.6-1.2, and the value range of Kf is 0.3-0.7.

[0061] e) Dynamic adjustment step: Send adjustment commands to the servo motor system driving the transfer film, and adjust its relative position in real time with a response time of no more than 10 milliseconds.

[0062] In one embodiment, the adjustment command is used to coordinate the speed and torque of the servo motor to maintain the tension fluctuation of the transfer film within ±5% through a tension closed loop while adjusting the position.

[0063] Specifically, the encoder sampling frequency of the aforementioned servo motor system is no less than 20kHz, and its controller is equipped with backlash compensation parameters to compensate for the mechanical backlash of the transmission mechanism.

[0064] f) Lamination step: Press and laminate the dynamically compensated and precisely aligned transfer film and metal sheet together.

[0065] g) Quality inspection and feedback steps: Online detection of the alignment accuracy of the composite product. When the accuracy continuously exceeds the preset tolerance, the control parameters are adjusted in reverse or an alarm is triggered.

[0066] In one embodiment, the criterion for continuously exceeding the preset tolerance is: when the test results exceed the ±0.2mm tolerance range for 3 consecutive times, parameter adjustment or alarm is triggered.

[0067] Specifically, when the first deviation is detected, the system records it but takes no action; when the second deviation is detected, the system issues a warning and prepares to adjust the parameters; when the third consecutive deviation is detected, the system immediately performs parameter adjustment or triggers an alarm to ensure a rapid response to abnormal situations.

[0068] See Figure 5 The image includes a product comparison diagram. The left side shows the product with deviations, where there is a significant misalignment between the metal sheet and the composite layer, with an edge misalignment exceeding 0.2mm. Some areas show uneven overlap or excessive gaps, and the relative position of the hot stamping pattern and the substrate baseline deviates from the preset trajectory. The right side shows the good product, where the metal sheet and composite layer are precisely aligned, the edges are neatly fitted, the misalignment is controlled within ±0.1mm, the hot stamping pattern falls completely within the preset baseline area, and the overall composite effect is uniform and consistent, meeting quality standards.

[0069] The present invention also provides a positioning cold ironing system for metal sheets, specifically comprising:

[0070] a) A conveying and attitude stabilization unit, including a guide mechanism for constraining the lateral position of the metal sheet and a pressure compensation mechanism for compensating for changes in the thickness of the metal sheet.

[0071] The guiding mechanism adopts a rolling guiding method, including multiple sets of roller guiding devices, each equipped with an automatic clearance compensation function. The rollers use high-precision bearings (radial runout ≤0.05mm) and the surface is hardened (HRC≥58).

[0072] The automatic gap compensation function is achieved through pneumatic or hydraulic drive. It monitors the lateral position of the metal sheet in real time. When a deviation is detected, it automatically adjusts the position of the guide roller to ensure that the lateral gap is always kept within ≤0.1mm, so as to ensure the long-term stability of the device and avoid the decrease in accuracy due to equipment wear.

[0073] b) A dual-stage positioning unit, comprising a photoelectric sensor for detecting black and white stripes and a laser sensor for detecting a detection notch.

[0074] In one embodiment, to address the strong reflective properties of metal sheets, the present invention further employs a polarized laser + narrowband filter configuration: the laser beam emitted by the laser sensor is processed by a polarizer to form a laser with a specific polarization direction. When the laser irradiates the metal surface, the polarization state of the reflected light changes. The receiving end uses a polarization filter perpendicular to the transmitting end, which can effectively filter out directly reflected strong light and only receive scattered light signals. Simultaneously, the narrowband filter (bandwidth ≤ 10nm) further filters out ambient light interference.

[0075] Specifically, for highly reflective materials such as stainless steel (reflectivity ≥80%) and galvanized sheet (uneven surface coating reflectivity), the polarization degree of the polarized laser is ≥99%, the center wavelength of the narrowband filter matches the laser wavelength (e.g., 650nm±5nm), and the transmittance is ≥90%. This configuration ensures signal stability in highly reflective environments and avoids false triggering or missed detection.

[0076] c) A drive unit, including a servo motor system for driving the transfer film.

[0077] d) A controller, electrically connected to the positioning unit and the drive unit, which internally stores and executes a program for implementing the positioning cold stamping process on the metal sheet as described above.

[0078] Furthermore, the controller is configured to dynamically adjust its control gains Kp and Kf based on the thickness or hardness parameters of the metal sheet being processed, either by querying a preset lookup table or by calculating using a fuzzy logic controller. To achieve adaptive control for different metal sheets, the controller incorporates a material parameter database and a fuzzy logic controller. When processing a new metal sheet, the system first identifies the material type (using parameters such as thickness and hardness), then queries the database for corresponding control parameters or calculates the optimal parameters using the fuzzy logic controller.

[0079] In one embodiment, such as Figure 6 As shown (the product being inspected in the figure is only an example), the positioning cold ironing system of the present invention also includes an online quality inspection unit, located downstream of the composite workstation, for inspecting the accuracy of the finished product and feeding back data to the controller. The online quality inspection unit adopts visual inspection technology, achieving an inspection accuracy of ±0.05mm. The system is equipped with a high-resolution industrial camera (resolution ≥5MP), coupled with a telecentric lens and a ring LED light source, to ensure the accuracy and stability of the inspection.

[0080] The visual inspection algorithm employs sub-pixel edge detection technology, using image processing algorithms to accurately measure the deviation between the transfer film pattern and the predetermined position on the metal sheet. The inspection data is fed back to the controller in real time for dynamic parameter adjustment and process optimization.

[0081] The specific control process of the positioning cold ironing system of this invention is as follows:

[0082] Step 1: The system identifies the basic parameters of the metal sheet through a thickness sensor and a hardness detection device, and sets the corresponding k and h values ​​according to the material type.

[0083] Step 2: The photoelectric sensor first detects the black and white stripes to complete the coarse positioning (accuracy of approximately ±0.5mm); then the laser sensor detects the notch to complete the precise positioning (accuracy of ±0.1mm).

[0084] Step 3: Calculate the current offset based on the duration of the laser signal, combine it with historical data to predict the trend, and calculate the predicted offset.

[0085] Step 4: Calculate the total compensation amount based on the current offset and the predicted offset, and send adjustment commands to the servo motor to achieve real-time position compensation.

[0086] Step 5: After completing the position compensation, the transfer film is laminated with the metal sheet, and then the precision of the finished product is checked by the online quality inspection unit.

[0087] Step 6: Based on the quality inspection results, adjust the control parameters in reverse to achieve continuous optimization of the process.

[0088] Of course, the above are only preferred embodiments of the present invention and are not intended to limit the scope of application of the present invention. Therefore, any equivalent changes made to the principle of the present invention should be included within the protection scope of the present invention.

Claims

1. A process for the cold embossing of a metal sheet, characterized in that, Includes the following steps: a) Preparation steps: On the transfer film and the metal sheet used as the substrate, black and white stripes for preliminary positioning and detection notches for precise positioning are respectively made. The edge roughness Ra of the black and white stripes is ≤0.1mm and the edge straightness of the detection notches is ≤0.1mm. b) Conveying and attitude stabilization steps: When conveying the metal sheet, its conveying attitude is actively controlled by a guiding mechanism with a lateral gap of no more than 0.05 mm and a pressure compensation mechanism. The pressure compensation mechanism is based on the formula Dynamically set the pressure roller pressure P. Where k is the pressure reference coefficient, d is the thickness of the metal sheet, and h is the hardness correction coefficient of the metal sheet; c) Two-stage positioning and offset calculation steps: First, a photoelectric sensor is used to detect the black and white stripes to complete coarse positioning. Then, a laser sensor is used to detect the detection gap, the actual duration t of the laser signal is measured, and the offset distance formula is applied. Calculate the current offset. Where L is the length of the detection gap and v is the conveying speed; d) Trend prediction and compensation calculation steps: Based on the current offset Δm, the adaptive predictive feedforward control algorithm is run by the controller, including: i. Trend Prediction: Based on the most recent N historical offset data, the predicted offset is calculated using a weighted moving average algorithm. ,in For the weighting coefficients, satisfying ; ii. Compensation Calculation: According to the formula Calculate the total compensation A, where Kp is the proportional gain and Kf is the feedforward gain; e) Dynamic adjustment step: Send adjustment commands to the servo motor system driving the transfer film to adjust its relative position in real time with a response time of no more than 10 milliseconds; f) Lamination step: Press and laminate the dynamically compensated and precisely aligned transfer film and metal sheet together; g) Quality inspection and feedback steps: Online detection of the alignment accuracy of the composite product. When the accuracy continuously exceeds the preset tolerance, the control parameters are adjusted in reverse or an alarm is triggered.

2. The positioning cold-stamping process on metal sheets as described in claim 1, characterized in that, The pressure reference coefficient k is determined based on the material of the metal sheet; The hardness correction factor h is determined based on the Vickers hardness HV value: when HV≤100, h=1.0-1.2; when HV=100-200, h=1.5-1.8; when HV≥200, h=1.8-2.

0.

3. The positioning cold-stamping process on metal sheets as described in claim 1, characterized in that, In the offset calculation step c), the offset distance formula The applicable conditions are as follows ,when If the reading is abnormal, the measurement data is discarded.

4. The positioning cold-stamping process on metal sheets as described in claim 1, characterized in that, In the trend prediction step i), before performing the weighted moving average calculation, abnormal offset data caused by sensor interference is filtered out by a threshold method, and the threshold is set to 3 times the standard deviation.

5. The positioning cold-stamping process on metal sheets as described in claim 1, characterized in that, The proportional gain Kp and feedforward gain Kf are dynamically adjusted based on the thickness d and hardness h of the metal sheet, either by looking up a preset table or by calculation through a fuzzy logic controller. The value range of Kp is 0.6-1.2, and the value range of Kf is 0.3-0.

7.

6. The positioning cold-stamping process on metal sheets as described in claim 1, characterized in that, The adjustment command in the dynamic adjustment step e) coordinates the speed and torque of the servo motor to maintain the tension fluctuation of the transfer film within ±5% range through tension closed loop while adjusting the position.

7. The positioning cold-stamping process on metal sheets as described in claim 1, characterized in that, The encoder sampling frequency of the servo motor system is not less than 20kHz, and its controller is equipped with a backlash compensation parameter to compensate for the mechanical backlash of the transmission mechanism.

8. A positioning cold-ironing system for metal sheets, characterized in that, include: a) A conveying and attitude stabilization unit, including a guiding mechanism for constraining the lateral position of the metal sheet and a pressure compensation mechanism for compensating for changes in the thickness of the metal sheet; b) A dual-stage positioning unit, comprising a photoelectric sensor for detecting black and white stripes and a laser sensor for detecting a detection notch; c) A drive unit, including a servo motor system for driving the transfer film; d) A controller, electrically connected to the dual-stage positioning unit and the drive unit, which internally stores and executes a program for implementing the positioning cold-stamping process on a metal sheet as described in any one of claims 1 to 7.

9. The positioning cold ironing system for metal sheets as described in claim 8, characterized in that, The controller is further configured to dynamically adjust its control gains Kp and Kf based on the thickness or hardness parameters of the processed metal sheet by querying a preset lookup table or by calculating through a fuzzy logic controller.

10. The positioning cold ironing system for metal sheets as described in claim 8, characterized in that, It includes an online quality inspection unit, located downstream of the composite workstation, used to detect the accuracy of the finished product and feed data back to the controller.

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