A PID-based hot-pressing temperature uniformity control device, method, and system

Abstract

This invention relates to the field of hot pressing molding technology and automatic control of polymer materials, and particularly to a PID-based hot pressing temperature uniformity control device, method, and system. The device's temperature field monitoring module generates a two-dimensional temperature field matrix by filtering and reconstructing sensor signals. A zone control module identifies high-temperature and low-temperature zones based on matrix region analysis, instantiates an independent PID controller for each zone, and generates differentiated power adjustment commands according to preset PID parameters. A process coupling module calculates the root mean square value of the temperature deviation of all zones as a uniformity index, triggering a pressing command only when the index is below a threshold and the temperature meets the target. This invention effectively overcomes the problem of uneven temperature distribution during hot pressing through zone control and coordinated temperature and pressure control, improving the bonding strength and density uniformity of the product, and preventing edge glue overflow defects.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of polymer material hot pressing forming process and automatic control, and particularly relates to a hot pressing temperature uniform control device, method and system based on PID. BACKGROUND

[0002] In the multi-layer adhesive hot sealing and pressing technology of polymer materials, the temperature uniform control of the hot pressing process is directly related to the quality of the adhesive interface. The controller can finely adjust the heating unit, dynamically adjust the heating power based on real-time temperature feedback, quickly respond to the deviation of the proportional element, eliminate the accumulated error of the integral element, and suppress the overshoot of the differential element, thereby improving the stability of the temperature distribution.

[0003] The existing multi-layer adhesive hot sealing and pressing technology of polymer materials has the following technical problems. In the hot pressing process, the multi-physical field coupling effect of heat conduction, convection and radiation interacts with environmental temperature fluctuations, different material layer heat absorption characteristics and other system disturbance factors, resulting in uneven temperature distribution in the hot pressing area. For example, in the hot sealing process of polymer material devices with complex laminated structure and fine micro-channels, uneven temperature will cause different heating of each layer of material, and local areas may have excessive adhesive flow due to excessive temperature, while areas with insufficient temperature may have weak adhesive interface strength and delamination due to insufficient activation of the adhesive, ultimately causing product layer density differences and flow channel size deformation. SUMMARY

[0004] To solve the technical problems of the prior art, the present application provides a hot pressing temperature uniform control device, method and system based on PID, which solves the problem of uneven temperature distribution caused by multi-physical field coupling and system disturbance in the hot pressing process, and the quality defects of insufficient adhesive strength, uneven density and edge overflow of the multi-layer adhesive hot sealing and pressing product of polymer materials.

[0005] To solve the above technical problems, the specific content of the present application is as follows:

[0006] In a first aspect, the present application provides a hot pressing temperature uniform control device based on PID, which comprises a physical execution unit and a control unit.

[0007] The physical execution unit comprises a hot pressing module, a vacuum servo press, a multi-hole pressing mold jig with partitioned independent heating plates and heat dissipation structures, and a temperature sensor array arranged on the mold jig and the surface of the workpiece.

[0008] The control unit is in communication connection with the physical execution unit and is used for controlling the physical execution unit. The control unit comprises:

[0009] The temperature field monitoring module is configured to receive the synchronous acquisition signal from the temperature sensor array, and after filtering and reconstruction processing, output a two-dimensional temperature field matrix characterizing the temperature distribution of the hot-pressed plane.

[0010] The zone control module is configured to receive a two-dimensional temperature field matrix from the temperature field monitoring module and perform regional analysis on the matrix to identify high-temperature and low-temperature zones; and to instantiate an independent PID controller for each zone. Each PID controller generates a differentiated power adjustment command to drive the heating plate of the corresponding zone based on the deviation between the real-time temperature and the set temperature of its corresponding zone and according to preset PID parameters.

[0011] The process coupling module is configured to calculate the root mean square value of the deviation between the real-time temperature and the set temperature of all zones as a temperature uniformity index, and only issue a pressing permission command to the vacuum servo press when the temperature uniformity index is lower than the set temperature uniformity threshold and the temperature of all zones is within the set value range.

[0012] Furthermore, in the PID-based hot-pressing temperature uniformity control device of the present invention, the temperature field monitoring module is configured as follows:

[0013] The synchronously acquired signal is smoothed using a hardware filter, and then the Kalman filter algorithm is used to eliminate random noise from the smoothed signal, outputting the pre-processed discrete temperature point data.

[0014] The generation of the two-dimensional temperature field matrix specifically involves inputting the preprocessed discrete temperature point data into a temperature field reconstruction algorithm based on a radial basis function neural network. The temperature field reconstruction algorithm takes the sensor physical coordinates corresponding to the discrete temperature point data as input and outputs the two-dimensional temperature field matrix.

[0015] Furthermore, in the PID-based hot-pressing temperature uniformity control device of the present invention, the partition control module is configured as follows:

[0016] The two-dimensional temperature field matrix is ​​subjected to region segmentation and cluster analysis to identify high-temperature and low-temperature regions, and the identification results are obtained.

[0017] Based on the identification results, a set of PID parameters is configured for the PID controller corresponding to the high-temperature zone, and another set of PID parameters is configured for the PID controller corresponding to the low-temperature zone. Among them, the proportional gain in the PID parameters configured for the high-temperature zone is less than the proportional gain in the PID parameters configured for the low-temperature zone; the integral time in the PID parameters configured for the high-temperature zone is greater than the integral time in the PID parameters configured for the low-temperature zone.

[0018] All configured PID controllers run in parallel to generate differentiated power adjustment commands to drive the corresponding zone heating plates.

[0019] Furthermore, in the PID-based hot-pressing temperature uniformity control device of the present invention, the process coupling module is configured as follows:

[0020] The root mean square value of the temperature deviation between all zones and the set temperature is calculated as an index of temperature uniformity.

[0021] During the pressing and holding operation of the vacuum servo press, the process coupling module continuously compares the temperature uniformity index with the temperature uniformity set threshold. When the temperature uniformity index exceeds the temperature uniformity set threshold due to the pressing pressure, the process coupling module triggers the vacuum servo press to perform pressure adjustment or stop the holding operation.

[0022] Furthermore, the PID-based hot-pressing temperature uniformity control device of the present invention further includes:

[0023] The differentiated power adjustment command generated by the partition control module drives the heating plate of the corresponding partition to work, thereby adjusting the temperature distribution in the hot pressing area;

[0024] The temperature field monitoring module acquires the updated temperature sensor array signal in real time, and outputs the updated two-dimensional temperature field matrix to the partition control module after filtering and reconstruction.

[0025] The partition control module re-segments and clusters the regions based on the updated two-dimensional temperature field matrix, identifies the current high-temperature and low-temperature regions, and generates new differentiated power adjustment commands, thereby forming a closed-loop control system.

[0026] Secondly, the present invention provides a PID-based hot-pressing temperature uniformity control method, applied to the PID-based hot-pressing temperature uniformity control device as described above, comprising:

[0027] Step S1: Receive the synchronous acquisition signal from the temperature sensor array arranged on the surface of the mold fixture and the workpiece, filter and reconstruct the synchronous acquisition signal, and output a two-dimensional temperature field matrix characterizing the temperature distribution of the hot-pressed plane.

[0028] Step S2: Receive the two-dimensional temperature field matrix from step S1, and perform regional analysis on the two-dimensional temperature field matrix to identify high-temperature and low-temperature regions;

[0029] Step S3: Receive the identified high temperature zone and low temperature zone information from step S2, instantiate an independent PID controller for each zone, and generate differentiated power adjustment commands to drive the heating plate of the corresponding zone based on the deviation between the real-time temperature and the set temperature of the corresponding zone and the preset PID parameters.

[0030] Step S4: Calculate the root mean square value of the deviation between the real-time temperature and the set temperature of all zones as the temperature uniformity index, and only issue a pressing permission command to the vacuum servo press when the temperature uniformity index is lower than the temperature uniformity set threshold and the temperature of all zones is within the set value range.

[0031] Furthermore, in the PID-based hot-pressing temperature uniform control method of the present invention, step S2 includes: calculating the average temperature of each partition in the two-dimensional temperature field matrix, comparing the average temperature of each partition with the overall average temperature; when the average temperature of each partition is higher than a first set percentage of the overall average temperature, it is marked as a high-temperature zone; when the average temperature of each partition is lower than a second set percentage of the overall average temperature, it is marked as a low-temperature zone.

[0032] Furthermore, in the PID-based hot-pressing temperature uniform control method of the present invention, step S3 includes:

[0033] Configure the first set of PID parameters for the PID controller corresponding to the high-temperature zone;

[0034] Configure a second set of PID parameters for the PID controller corresponding to the low-temperature region;

[0035] Among them, the proportional gain in the first group of PID parameters is less than the proportional gain in the second group of PID parameters;

[0036] The integral time in the first set of PID parameters is greater than the integral time in the second set of PID parameters.

[0037] Furthermore, in the PID-based hot-pressing temperature uniform control method of the present invention, step S4 further includes:

[0038] During the pressing and holding operation of the vacuum servo press, the process coupling module continuously compares the temperature uniformity index with the temperature uniformity set threshold. When the temperature uniformity index exceeds the temperature uniformity set threshold due to the pressing pressure, the process coupling module triggers the vacuum servo press to perform pressure adjustment or stop the holding operation.

[0039] Thirdly, the present invention provides a PID-based hot-pressing temperature uniformity control system, comprising:

[0040] The physical execution unit includes a hot pressing module, a vacuum servo press, a multi-cavity pressing mold fixture with built-in partitioned independent heating plates and heat dissipation structures, and a temperature sensor array arranged on the surface of the mold fixture and the workpiece.

[0041] The control unit is communicatively connected to the physical execution unit and is used to execute the PID-based hot-pressing temperature uniform control method as described above.

[0042] Beneficial effects of this invention;

[0043] This invention synchronously acquires signals from a temperature sensor array via a temperature field monitoring module, and then filters and reconstructs them to generate a two-dimensional temperature field matrix, comprehensively characterizing the temperature distribution of the hot-pressed plane. This solves the problem that existing point-based temperature measurement methods cannot fully capture the temperature distribution. The zone control module divides the area based on the two-dimensional temperature field matrix and identifies high-temperature and low-temperature zones. An independent PID controller is instantiated for each zone, and precise zone control is achieved through preset differentiated PID parameters. In the high-temperature zone, a parameter combination of decreasing proportional gain and increasing integral time is used to suppress temperature fluctuations; in the low-temperature zone, a parameter combination of increasing proportional gain and decreasing integral time is used to accelerate the temperature response. This effectively compensates for local temperature deviations caused by the coupling of multiple physical fields such as heat conduction, convection, and radiation, as well as differences in the heat absorption characteristics of the material layers. The process coupling module calculates the root mean square value of the temperature deviation between all zones and the set temperature as a temperature uniformity index. Only when the index is lower than the set temperature uniformity threshold and all zone temperatures are within the allowable range, a pressing command is issued to the vacuum servo press. During the pressure holding stage, the index changes are continuously monitored, and temperature uniformity is maintained by fine-tuning the pressure or interrupting the pressure holding, thus avoiding insufficient activation or excessive flow of the adhesive. The system drives the heating plate to cause temperature field changes through power adjustment commands. The temperature field monitoring module updates the two-dimensional temperature field matrix, and the zone control module re-identifies the temperature zone and adjusts the commands, forming a closed-loop control cycle to dynamically maintain the temperature uniformity during the hot pressing process. This improves the bonding strength and density uniformity of the multilayer polymer adhesive heat-sealed products and prevents edge overflow defects. Attached Figure Description

[0044] To more clearly illustrate the technical solution of the present invention, the drawings used in the embodiments will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on the drawings without creative effort.

[0045] Figure 1 This is a flowchart of a PID-based hot-pressing temperature uniformity control method provided in an embodiment of the present invention. Detailed Implementation

[0046] To make the technical solution of the present invention clearer, the present invention will be clearly and completely described below with reference to specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. The present invention provided by various embodiments will be described in detail below with reference to the accompanying drawings. To better understand the purpose of the present invention, the present invention will be described in further detail below.

[0047] In a first aspect, the present invention provides a PID-based hot-pressing temperature uniformity control device, comprising: the device including a physical execution unit and a control unit;

[0048] The physical execution unit includes a hot pressing module, a vacuum servo press, a multi-cavity pressing mold fixture with built-in partitioned independent heating plates and heat dissipation structures, and a temperature sensor array arranged on the surface of the mold fixture and the workpiece.

[0049] The control unit is communicatively connected to the physical execution unit and is used to control the physical execution unit. The control unit includes:

[0050] The temperature field monitoring module is configured to receive the synchronous acquisition signal from the temperature sensor array, and after filtering and reconstruction processing, output a two-dimensional temperature field matrix characterizing the temperature distribution of the hot-pressed plane.

[0051] The zone control module is configured to receive a two-dimensional temperature field matrix from the temperature field monitoring module and perform regional analysis on the matrix to identify high-temperature and low-temperature zones; and to instantiate an independent PID controller for each zone. Each PID controller generates a differentiated power adjustment command to drive the heating plate of the corresponding zone based on the deviation between the real-time temperature and the set temperature of its corresponding zone and according to preset PID parameters.

[0052] The process coupling module is configured to calculate the root mean square value of the deviation between the real-time temperature and the set temperature of all zones as a temperature uniformity index, and only issue a pressing permission command to the vacuum servo press when the temperature uniformity index is lower than the set temperature uniformity threshold and the temperature of all zones is within the set value range.

[0053] The temperature field monitoring module synchronously acquires temperature signals from multiple discrete points within the hot-pressing area using a temperature sensor array. This module first employs a hardware filter to smooth the raw signals and suppress high-frequency interference. Subsequently, a Kalman filter algorithm is applied to further eliminate random noise, resulting in pre-processed discrete temperature point data. This discrete temperature point data, along with their corresponding sensor physical coordinates, is input into a temperature field reconstruction algorithm based on a radial basis function neural network. Spatial interpolation is used to generate a continuously distributed two-dimensional temperature field matrix, thus comprehensively characterizing the temperature distribution of the hot-pressing plane.

[0054] After receiving the two-dimensional temperature field matrix output by the temperature field monitoring module, the zone control module performs zone processing on the matrix using region segmentation and cluster analysis methods. It identifies high-temperature and low-temperature zones by calculating the deviation between the average temperature of each sub-region and the overall average. For each identified temperature zone, the module instantiates an independent PID controller. Each zone's PID controller generates differentiated power adjustment commands based on the deviation between the real-time temperature and the set temperature of its corresponding zone, combined with preset PID parameters. Specifically, the PID controller for the high-temperature zone uses a parameter combination of decreasing proportional gain and increasing integral time to smoothly suppress temperature fluctuations; the PID controller for the low-temperature zone uses a parameter combination of increasing proportional gain and decreasing integral time to rapidly improve temperature response speed. All zone controllers operate in parallel, outputting independent PWM signals to drive the heating plates of their respective zones.

[0055] The process coupling module calculates the root mean square (RMS) value of the temperature deviation between all zones and the set temperature in real time, using it as a quantitative indicator to evaluate the overall temperature uniformity. This module continuously compares the temperature uniformity indicator with a preset threshold, issuing a pressing permission command to the vacuum servo press only when the indicator is below the threshold and all zone temperatures are within the set range. During the pressing and holding phase, the module continuously monitors changes in the temperature uniformity indicator. When the indicator deteriorates due to pressure and exceeds the threshold, it immediately triggers a pressure fine-tuning mechanism or interrupts the holding process, forming a coordinated temperature and pressure control system.

[0056] After the differentiated power adjustment commands generated by the zone control module drive the heating plate to work, they cause dynamic changes in the temperature field of the hot-pressing area. The temperature field monitoring module continuously collects new temperature signals and updates the two-dimensional temperature field matrix. Based on the updated matrix, the zone control module re-identifies the temperature distribution characteristics and adjusts the power adjustment commands, thus forming a closed-loop control system. This system achieves dynamic maintenance of temperature uniformity during the hot-pressing process through periodic signal acquisition, temperature field reconstruction, zone identification, and power adjustment.

[0057] The multi-cavity pressing mold fixture in the physical execution unit adopts a zoned independent heating plate design. Each heating plate corresponds to a specific area of ​​the hot pressing plane and can independently receive PWM signals from the zoned control module. A temperature sensor array is evenly distributed on the surface of the mold fixture in contact with the workpiece, and a synchronous acquisition mechanism ensures the temporal consistency of temperature data at each point. The vacuum servo press receives instructions from the process coupling module and executes the pressing operation; its pressure output is linked to the temperature control process.

[0058] Specifically, in the PID-based hot-pressing temperature uniformity control device of the present invention, the temperature field monitoring module is configured as follows:

[0059] The synchronously acquired signal is smoothed using a hardware filter, and then the Kalman filter algorithm is used to eliminate random noise from the smoothed signal, outputting the pre-processed discrete temperature point data.

[0060] The generation of the two-dimensional temperature field matrix specifically involves inputting the preprocessed discrete temperature point data into a temperature field reconstruction algorithm based on a radial basis function neural network. The temperature field reconstruction algorithm takes the sensor physical coordinates corresponding to the discrete temperature point data as input and outputs the two-dimensional temperature field matrix.

[0061] The temperature field monitoring module acquires synchronous signals through a temperature sensor array. The signals are first smoothed by a hardware filter to suppress high-frequency interference. The hardware filter uses a passive filter circuit based on a resistor-capacitor network or an active filter circuit composed of integrated operational amplifiers to perform low-pass filtering. The filtered signal is then sent to the microprocessor unit for secondary processing using a Kalman filter algorithm to further eliminate random noise and output preprocessed discrete temperature point data. The discrete temperature point data corresponds to the physical coordinates of the sensors on the mold surface, and a two-dimensional temperature field matrix is ​​generated through spatial interpolation. The row and column structure of the two-dimensional temperature field matrix corresponds to the spatial layout of the hot-pressing plane, and the matrix elements represent the temperature values ​​at the corresponding locations, thus comprehensively characterizing the temperature distribution.

[0062] Specifically, in the PID-based hot-pressing temperature uniformity control device of the present invention, the partition control module is configured as follows:

[0063] The two-dimensional temperature field matrix is ​​subjected to region segmentation and cluster analysis to identify high-temperature and low-temperature regions, and the identification results are obtained.

[0064] Based on the identification results, a set of PID parameters is configured for the PID controller corresponding to the high-temperature zone, and another set of PID parameters is configured for the PID controller corresponding to the low-temperature zone. Among them, the proportional gain in the PID parameters configured for the high-temperature zone is less than the proportional gain in the PID parameters configured for the low-temperature zone; the integral time in the PID parameters configured for the high-temperature zone is greater than the integral time in the PID parameters configured for the low-temperature zone.

[0065] All configured PID controllers run in parallel to generate differentiated power adjustment commands to drive the corresponding zone heating plates.

[0066] After receiving the two-dimensional temperature field matrix, the zone control module uses a grid partitioning method to uniformly divide the matrix into multiple sub-regions. Each sub-region calculates its average temperature and compares it with the overall average temperature, identifying high-temperature and low-temperature zones by setting percentage thresholds. High-temperature zones are those where the average temperature is a certain percentage higher than the overall average, and low-temperature zones are those where the average temperature is a certain percentage lower than the overall average. After identification, the module instantiates an independent PID controller for each zone. The PID controller for the high-temperature zone is configured with one set of parameters, including decreasing the proportional gain and increasing the integral time, to reduce response speed and prevent temperature overshoot; the PID controller for the low-temperature zone is configured with another set of parameters, including increasing the proportional gain and decreasing the integral time, to improve response speed and quickly reach the set temperature. All PID controllers run in parallel, generating independent pulse-width modulation signals based on the deviation between the real-time temperature and the set temperature of each zone, driving the heating plate of the corresponding zone.

[0067] Specifically, in the PID-based hot-pressing temperature uniformity control device of the present invention, the process coupling module is configured as follows:

[0068] The root mean square value of the temperature deviation between all zones and the set temperature is calculated as an index of temperature uniformity.

[0069] During the pressing and holding operation of the vacuum servo press, the process coupling module continuously compares the temperature uniformity index with the temperature uniformity set threshold. When the temperature uniformity index exceeds the temperature uniformity set threshold due to the pressing pressure, the process coupling module triggers the vacuum servo press to perform pressure adjustment or stop the holding operation.

[0070] The process coupling module calculates the root mean square (RMS) value of the temperature deviation between all zones and the set temperature in real time, serving as a temperature uniformity index. This index quantifies the uniformity of temperature distribution. During the pressing and holding phase, the module continuously compares the temperature uniformity index with a set threshold. When the index deteriorates due to pressure changes and exceeds the threshold, the module triggers a pressure fine-tuning mechanism, adjusting the pressing pressure via a vacuum servo press or interrupting the holding process. Pressure fine-tuning is based on pressure sensor feedback and employs a gradual adjustment strategy to progressively optimize the pressure value. When holding is interrupted, the system pauses the pressing operation until the temperature uniformity index recovers to within the threshold range before resuming.

[0071] Specifically, the PID-based hot-pressing temperature uniformity control device of the present invention further includes:

[0072] The differentiated power adjustment command generated by the partition control module drives the heating plate of the corresponding partition to work, thereby adjusting the temperature distribution in the hot pressing area;

[0073] The temperature field monitoring module acquires the updated temperature sensor array signal in real time, and outputs the updated two-dimensional temperature field matrix to the partition control module after filtering and reconstruction.

[0074] The partition control module re-segments and clusters the regions based on the updated two-dimensional temperature field matrix, identifies the current high-temperature and low-temperature regions, and generates new differentiated power adjustment commands, thereby forming a closed-loop control system.

[0075] The zone control module generates differentiated power adjustment commands to drive the heating plate, causing changes in the temperature field of the hot-pressing area. The temperature field monitoring module synchronously acquires new temperature signals through a temperature sensor array, filters and reconstructs them, and outputs an updated two-dimensional temperature field matrix. The zone control module receives the updated matrix, re-segments and clusters the regions, and identifies the current high-temperature and low-temperature zones. Based on the updated temperature distribution, the module adjusts the output of the PID controllers in each zone, generating new differentiated power adjustment commands. This process is repeated periodically, forming a closed-loop control system to dynamically maintain temperature uniformity.

[0076] Secondly, please refer to Figure 1 This invention provides a PID-based hot-pressing temperature uniformity control method, applied to the PID-based hot-pressing temperature uniformity control device as described above, comprising:

[0077] Step S1: Receive the synchronous acquisition signal from the temperature sensor array arranged on the surface of the mold fixture and the workpiece, filter and reconstruct the synchronous acquisition signal, and output a two-dimensional temperature field matrix characterizing the temperature distribution of the hot-pressed plane.

[0078] Step S2: Receive the two-dimensional temperature field matrix from step S1, and perform regional analysis on the two-dimensional temperature field matrix to identify high-temperature and low-temperature regions;

[0079] Step S3: Receive the identified high temperature zone and low temperature zone information from step S2, instantiate an independent PID controller for each zone, and generate differentiated power adjustment commands to drive the heating plate of the corresponding zone based on the deviation between the real-time temperature and the set temperature of the corresponding zone and the preset PID parameters.

[0080] Step S4: Calculate the root mean square value of the deviation between the real-time temperature and the set temperature of all zones as the temperature uniformity index, and only issue a pressing permission command to the vacuum servo press when the temperature uniformity index is lower than the temperature uniformity set threshold and the temperature of all zones is within the set value range.

[0081] A temperature sensor array synchronously acquires temperature signals from multiple discrete points on the surface of the mold fixture and the workpiece. The signals undergo preliminary smoothing via a hardware filter to suppress high-frequency interference, and are then converted into digital signals by an analog-to-digital converter. The digital signals are further filtered to eliminate random noise, outputting pre-processed discrete temperature point data. These discrete temperature point data correspond to the physical coordinates of the sensors, and a two-dimensional temperature field matrix is ​​generated through spatial interpolation. The row and column structure of the two-dimensional temperature field matrix maps to the spatial layout of the hot-pressing plane, and the numerical values ​​of the matrix elements represent the temperature values ​​at corresponding locations, thus comprehensively reflecting the temperature distribution.

[0082] After receiving the two-dimensional temperature field matrix, the system divides the matrix into multiple regular grid regions, calculating the average temperature for each region. The average temperature of each grid region is compared with the overall average temperature. Regions with an average temperature higher than the overall average temperature by a set percentage are marked as high-temperature regions, while those with an average temperature lower than the set percentage are marked as low-temperature regions. Region identification is based on a temperature deviation threshold to classify regions, providing a foundation for subsequent control.

[0083] Based on the identified high-temperature and low-temperature zones, the system instantiates an independent digital PID controller for each zone. Each PID controller receives the real-time temperature signal and set temperature value for its corresponding zone and calculates the temperature deviation. According to preset proportional gain, integral time, and derivative time parameters, the PID controller generates a control signal, which is converted into a pulse-width modulation (PWM) signal to drive the heating plate of the corresponding zone. The PID controller in the high-temperature zone uses a parameter combination of decreasing proportional gain and increasing integral time for smooth adjustment, while the PID controller in the low-temperature zone uses a parameter combination of increasing proportional gain and decreasing integral time for faster response.

[0084] The system calculates the root mean square (RMS) value of the deviation between the real-time temperature and the set temperature of all zones as a temperature uniformity index. This index is used to evaluate the overall temperature distribution uniformity. During the pressing process, the temperature uniformity index is continuously compared with the set threshold, while monitoring whether the temperature of each zone is within the set range. Only when the temperature uniformity index is below the threshold and the temperature of all zones is within the allowable range, the system issues a pressing permission command to the vacuum servo press. During the pressure holding phase, if the temperature uniformity index deteriorates due to pressure changes and exceeds the threshold, the system triggers a pressure fine-tuning mechanism or interrupts the pressure holding process to maintain temperature uniformity.

[0085] Specifically, in the PID-based hot-pressing temperature uniform control method of the present invention, step S2 includes: calculating the average temperature of each partition in the two-dimensional temperature field matrix, comparing the average temperature of each partition with the overall average temperature; when the average temperature of each partition is higher than a first set percentage of the overall average temperature, it is marked as a high-temperature zone; when the average temperature of each partition is lower than a second set percentage of the overall average temperature, it is marked as a low-temperature zone.

[0086] For the calculation of the average temperature of each zone in step S2, the system first divides the two-dimensional temperature field matrix into multiple regular grid regions, each grid region including several matrix elements. The system calculates the arithmetic mean of the temperature values ​​of all matrix elements in each grid region as the average temperature of that zone. Simultaneously, the system calculates the arithmetic mean of the temperature values ​​of all elements in the entire two-dimensional temperature field matrix as the overall average temperature. The comparison between the average temperature of the zones and the overall average temperature uses percentage deviation calculation. When the average temperature of a zone is higher than the overall average temperature by a first set percentage, the zone is marked as a high-temperature zone; when the average temperature of a zone is lower than the overall average temperature by a second set percentage, the zone is marked as a low-temperature zone. The zone marking results are used for subsequent control strategy selection.

[0087] Specifically, in the PID-based hot-pressing temperature uniform control method of the present invention, step S3 includes:

[0088] Configure the first set of PID parameters for the PID controller corresponding to the high-temperature zone;

[0089] Configure a second set of PID parameters for the PID controller corresponding to the low-temperature region;

[0090] Among them, the proportional gain in the first group of PID parameters is less than the proportional gain in the second group of PID parameters;

[0091] The integral time in the first set of PID parameters is greater than the integral time in the second set of PID parameters.

[0092] In step S3, the system instantiates an independent digital PID controller for each zone based on the zone marking results. For zones marked as high-temperature zones, the system calls a preset first set of PID parameters, which includes a relatively small proportional gain and a relatively large integral time. Decreasing the proportional gain helps reduce the response speed of the control system and avoid temperature overshoot; increasing the integral time helps slow down the integral action and smooth the temperature regulation process. For zones marked as low-temperature zones, the system calls a preset second set of PID parameters, which includes a relatively large proportional gain and a relatively small integral time. Increasing the proportional gain helps improve the response speed of the control system and quickly eliminate temperature deviations; decreasing the integral time helps accelerate the integral action and improve temperature regulation efficiency. After the parameters are configured, the PID controllers for each zone run in parallel to achieve differentiated control.

[0093] Specifically, in the PID-based hot-pressing temperature uniform control method of the present invention, step S4 further includes:

[0094] During the pressing and holding operation of the vacuum servo press, the process coupling module continuously compares the temperature uniformity index with the temperature uniformity set threshold. When the temperature uniformity index exceeds the temperature uniformity set threshold due to the pressing pressure, the process coupling module triggers the vacuum servo press to perform pressure adjustment or stop the holding operation.

[0095] Step S4 continues during the pressing and holding phase. The system synchronously acquires new temperature signals through a temperature sensor array. These signals are processed by hardware and digital filters to eliminate noise and generate updated discrete temperature point data. The discrete temperature point data is reconstructed into an updated two-dimensional temperature field matrix through spatial interpolation. Based on this updated matrix, the system recalculates the root mean square (RMS) values ​​of the temperature deviations of all zones from the set temperature, obtaining an updated temperature uniformity index. The temperature uniformity index is compared in real-time with a set threshold. When the index deteriorates due to pressure changes and exceeds the threshold, the system triggers a pressure fine-tuning mechanism or interrupts the holding process. The pressure fine-tuning mechanism adjusts the pressing pressure using a vacuum servo press, employing a gradual adjustment strategy. Interrupting the holding process pauses the pressing operation until the temperature uniformity index recovers before resuming.

[0096] Thirdly, the present invention provides a PID-based hot-pressing temperature uniformity control system, comprising:

[0097] The physical execution unit includes a hot pressing module, a vacuum servo press, a multi-cavity pressing mold fixture with built-in partitioned independent heating plates and heat dissipation structures, and a temperature sensor array arranged on the surface of the mold fixture and the workpiece.

[0098] The control unit is communicatively connected to the physical execution unit and is used to execute the PID-based hot-pressing temperature uniform control method as described above.

[0099] This invention synchronously acquires temperature signals from multiple discrete points on the surface of the mold fixture and workpiece using a temperature sensor array. The signals are processed by hardware and digital filters to suppress high-frequency interference and random noise, outputting pre-processed discrete temperature point data. This discrete temperature point data is then used to generate a two-dimensional temperature field matrix through spatial interpolation. The row and column structure of this matrix corresponds to the spatial layout of the hot-pressing plane, and the matrix elements represent the temperature values ​​at their respective locations, thus comprehensively reflecting the temperature distribution within the hot-pressing region. This temperature field monitoring process solves the problem that existing point-based temperature measurements cannot fully capture the temperature distribution, providing a global temperature data foundation for subsequent control.

[0100] After receiving the two-dimensional temperature field matrix, the zoning control module divides the matrix into multiple regular grid regions, calculates the average temperature of each grid region, and compares it with the overall average temperature. A zone is marked as a high-temperature zone when its average temperature exceeds the overall average by a set percentage, and as a low-temperature zone when it falls below the set percentage. For each identified high-temperature and low-temperature zone, the module instantiates an independent digital PID controller. The PID controller for the high-temperature zone is configured with one set of parameters, including decreasing the proportional gain and increasing the integral time, to reduce response speed and avoid temperature overshoot; the PID controller for the low-temperature zone is configured with another set of parameters, including increasing the proportional gain and decreasing the integral time, to improve response speed and quickly eliminate deviations. All PID controllers run in parallel, generating independent pulse-width modulation signals to drive the heating plates in their respective zones. This zone-specific control strategy effectively compensates for local temperature differences caused by the coupling effects of multiple physical fields such as heat conduction, convection, and radiation, and overcomes system disturbances caused by uneven heat absorption characteristics of the material layers.

[0101] The process coupling module calculates the root mean square (RMS) value of the temperature deviation between all zone temperatures and the set temperature in real time as a temperature uniformity index, which quantifies the overall temperature distribution uniformity. The module continuously compares the temperature uniformity index with a set threshold, and only issues a pressing permission command to the vacuum servo press when the index is below the threshold and all zone temperatures are within the set range. During the pressing and holding pressure stage, the module continuously collects signals through a temperature sensor array and updates the two-dimensional temperature field matrix, recalculating the temperature uniformity index based on the updated matrix. If the index deteriorates due to pressure changes and exceeds the threshold, the module triggers a pressure fine-tuning mechanism to adjust the pressing pressure or interrupt the holding pressure process. This temperature and pressure coordinated control mechanism ensures that the hot pressing process is carried out only under uniform temperature conditions, avoiding insufficient adhesive activation or excessive flow caused by temperature unevenness, thereby preventing defects such as insufficient adhesive strength, interlayer density differences, and edge adhesive overflow in the product.

[0102] The system drives the heating plate through differentiated power adjustment commands generated by the zone control module, causing changes in the temperature field. The temperature field monitoring module continuously collects new signals and updates the two-dimensional temperature field matrix. Based on the updated matrix, the zone control module re-identifies the temperature zone and adjusts the control commands, forming a closed-loop control system. This cyclical process of periodic acquisition, reconstruction, identification, and adjustment dynamically maintains the temperature uniformity during the hot pressing process, improving the quality consistency of multilayer polymer adhesive heat-sealed products.

Claims

1. A PID-based hot-press temperature uniformity control device, characterized by, The device comprises a physical execution unit and a control unit. The physical execution unit comprises a hot-pressing mold group, a vacuum servo press, a multi-hole pressing mold jig with partitioned independent heating plates and heat dissipation structures built-in, and a temperature sensor array arranged on the mold jig and the surface of the workpiece. The control unit is in communication connection with the physical execution unit and is used for controlling the physical execution unit, and the control unit comprises: A temperature field monitoring module configured to receive synchronous acquisition signals of the temperature sensor array, and output a two-dimensional temperature field matrix representing the temperature distribution of the hot-pressing plane after filtering and reconstruction processing. A partition control module configured to receive the two-dimensional temperature field matrix from the temperature field monitoring module, and perform regional analysis on the matrix to identify high-temperature areas and low-temperature areas; instantiate an independent PID controller for each partition, and each PID controller generates a differentiated power adjustment instruction for driving the heating plate of the corresponding partition based on the deviation of the real-time temperature and the set temperature of the corresponding partition and according to the preset PID parameters. A process coupling module configured to calculate the root mean square value of the deviation of the real-time temperature and the set temperature of all partitions as a temperature uniformity index, and send a pressing instruction to the vacuum servo press when the temperature uniformity index is lower than a temperature uniformity set threshold and the temperature of all partitions enters the set value range. The partition control module is configured to: perform regional segmentation and clustering analysis on the two-dimensional temperature field matrix to identify high-temperature areas and low-temperature areas, and obtain an identification result; configure a set of PID parameters for the PID controller corresponding to the high-temperature area and another set of PID parameters for the PID controller corresponding to the low-temperature area according to the identification result; wherein the proportional gain in the PID parameters configured for the high-temperature area is less than the proportional gain in the PID parameters configured for the low-temperature area; and the integral time in the PID parameters configured for the high-temperature area is greater than the integral time in the PID parameters configured for the low-temperature area; all configured PID controllers run in parallel to generate differentiated power adjustment instructions for driving the heating plates of the corresponding partitions; The process coupling module is configured to: calculate the root mean square value of the deviation of the real-time temperature and the set temperature of all partitions as a temperature uniformity index; during the pressing and holding operation of the vacuum servo press, the process coupling module continuously compares the temperature uniformity index with the temperature uniformity set threshold, and when the temperature uniformity index is greater than the temperature uniformity set threshold due to the influence of the pressing pressure, the process coupling module triggers the vacuum servo press to perform pressure adjustment or stop the holding operation. The temperature field monitoring module is configured to:

2. The PID-based hot-press temperature uniformity control apparatus of claim 1, wherein, smooth the synchronous acquisition signals using a hardware filter, and eliminate random noise from the smoothed signals using a Kalman filtering algorithm to output preprocessed discrete temperature point data; the generation of the two-dimensional temperature field matrix comprises inputting the preprocessed discrete temperature point data into a temperature field reconstruction algorithm based on a radial basis function neural network, the temperature field reconstruction algorithm taking the physical coordinates of the sensors corresponding to the discrete temperature point data as input and outputting the two-dimensional temperature field matrix. Further comprising:

3. The PID-based hot bar temperature uniformity control device of claim 1, wherein, ​ The differential power adjustment instruction generated by the partition control module drives the operation of the heating plate corresponding to the partition, and adjusts the temperature distribution of the hot-pressing area; The temperature field monitoring module collects the updated temperature sensor array signal in real time, performs filtering and reconstruction processing, and outputs an updated two-dimensional temperature field matrix to the partition control module; The partition control module re-performs region segmentation and cluster analysis based on the updated two-dimensional temperature field matrix, identifies the current high-temperature area and low-temperature area, and generates a new differential power adjustment instruction, thereby forming a closed-loop control system.

4. A PID-based hot press temperature uniformity control method applied to the PID-based hot press temperature uniformity control apparatus according to any one of claims 1 to 3, characterized by, Comprising: Step S1: receiving the synchronous acquisition signal of the temperature sensor array arranged on the mold jig and the workpiece surface, filtering and reconstructing the synchronous acquisition signal, and outputting a two-dimensional temperature field matrix representing the temperature distribution of the hot-pressing plane; Step S2: receiving the two-dimensional temperature field matrix from step S1, and performing region analysis on the two-dimensional temperature field matrix to identify high-temperature areas and low-temperature areas; Step S3: receiving the identified high-temperature area and low-temperature area information from step S2, instantiating an independent PID controller for each partition, and generating a differential power adjustment instruction for driving the heating plate of the corresponding partition based on the deviation of the real-time temperature and the set temperature of the corresponding partition according to the preset PID parameters; Step S4: calculating the root mean square value of the deviation of the real-time temperature and the set temperature of all partitions as a temperature uniformity index, and only when the temperature uniformity index is lower than the temperature uniformity set threshold and the temperature of all partitions enters the set value range, issuing a pressing instruction to the vacuum servo press.

5. The PID-based hot bar temperature uniformity control method of claim 4, wherein, Step S2 includes: calculating the average temperature of each partition in the two-dimensional temperature field matrix, comparing the average temperature of each partition with the overall average temperature, marking a high-temperature area when the average temperature of each partition is higher than the overall average temperature by a first set percentage, and marking a low-temperature area when the average temperature of each partition is lower than the overall average temperature by a second set percentage.

6. The PID-based hot bar temperature uniformity control method of claim 5, wherein, Step S3 includes: configuring a first group of PID parameters for the PID controller corresponding to the high-temperature area; configuring a second group of PID parameters for the PID controller corresponding to the low-temperature area; wherein the proportional gain in the first group of PID parameters is less than the proportional gain in the second group of PID parameters; the integral time in the first group of PID parameters is greater than the integral time in the second group of PID parameters.

7. The PID-based hot bar temperature uniformity control method of claim 4, wherein, Step S4 further includes: During the pressing and holding operation of the vacuum servo press, the process coupling module continuously compares the temperature uniformity index with the temperature uniformity set threshold, and when the temperature uniformity index is greater than the temperature uniformity set threshold due to the influence of the pressing pressure, the process coupling module triggers the vacuum servo press to perform pressure adjustment or stop the holding operation.

8. A PID-based hot-press temperature uniformity control system, characterized by, Comprising: a physical execution unit, including a hot-pressing module, a vacuum servo press, a multi-hole pressing mold jig with partitioned independent heating plates and heat dissipation structures built-in, and a temperature sensor array arranged on the mold jig and the workpiece surface; a control unit, in communication connection with the physical execution unit, the control unit being configured to execute the PID-based hot-pressing temperature uniformity control method according to any one of claims 4 to 7.

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