Temperature closed-loop automatic control method and system suitable for laminated glass autoclave

Abstract

The application provides a temperature closed-loop automatic control method and system suitable for laminated glass autoclaves, which comprises the following steps: S1, selecting the working mode of the autoclave, setting the working parameters of the autoclave and generating a temperature control curve; S2, starting the autoclave; S3, calculating the temperature deviation between the actual temperature of different heating zones and the preset temperature target value; S4, inputting the temperature deviation calculated in S3 into the PID control algorithm; S5, changing the output power of the infrared heating tube, so that the actual temperature in the autoclave is consistent with the preset temperature target value. The application adopts a brand-new temperature closed-loop automatic control method, sets the production process temperature rising curve in the autoclave, calculates the temperature deviation between the actual temperature of each heating zone and the set temperature rising temperature in real time, adjusts the temperature deviation according to the PID control algorithm, then adjusts and changes the heating energy of the infrared heating tube, and further realizes the closed-loop control of the temperature of different heating zones in the autoclave.

Description

Technical Field

[0001] This invention relates to the field of electrical automatic control technology for laminated glass autoclaves, and in particular to a closed-loop automatic temperature control method and system suitable for laminated glass autoclaves. Background Technology

[0002] The autoclave is the final piece of equipment in the laminated glass production process, ensuring a tight bond between the glass and the interlayer film. By setting process parameters, including temperature and pressure, the interlayer film melts and presses into place, followed by rapid cooling and depressurization, ultimately producing laminated glass. The accuracy of temperature control significantly impacts the softening and shaping of the interlayer film in laminated glass. Traditional autoclaves regulate temperature by controlling the on / off state of solid-state relays, with infrared heating tubes operating at full load and zero load. This on / off control method suffers from complex control logic, high energy consumption, and poor adaptability to various operating conditions, reducing the yield of laminated glass. To address the temperature control problem, a closed-loop automatic temperature control method and system suitable for laminated glass autoclaves needs to be developed to effectively improve temperature control accuracy within the autoclave, increase the yield of laminated glass, reduce energy consumption, and increase production capacity. Summary of the Invention

[0003] To address the problems existing in the prior art, this invention provides a closed-loop automatic temperature control method and system suitable for laminated glass autoclaves, which solves the problems of complex control logic, high energy consumption, and poor adaptability to operating conditions in traditional autoclave on / off temperature control methods.

[0004] Specifically, on the one hand, the present invention provides a closed-loop automatic temperature control method suitable for laminated glass autoclaves, which includes the following steps:

[0005] S1. Close the autoclave door, select the autoclave's working mode as fully automatic control mode, set the autoclave's working parameters, and generate a temperature control curve;

[0006] S2. Press the start button, and the autoclave will start working, heating different heating areas inside the autoclave;

[0007] S3. Monitor the temperature of each heating zone in the autoclave in real time and calculate the temperature deviation between the actual temperature of different heating zones and the preset temperature target value.

[0008] S4. Input the temperature deviation calculated in step S3 into the PID control algorithm. The specific steps are as follows:

[0009] S41. Establish the transfer function model for the temperature control of the autoclave, and its expression is:

[0010] ;

[0011] In the formula, Indicates the switching gain; The time constant represents the first-order inertial element; Indicates the delay time; Represents the Laplace operator; Represents an exponential function;

[0012] S42. Set the output power of the power regulator to full power output so that the temperature inside the autoclave gradually rises until it remains stable, and record the temperature change data during the heating process of the autoclave.

[0013] S43. Using the recorded temperature change data, perform data fitting based on the high-pressure vessel temperature control transfer function model in step S41 to obtain the parameter values ​​of switching gain, first-order inertial element time constant, and delay time in the transfer function model.

[0014] S44. Treating each heating zone in the autoclave as an independent temperature control loop, establish a programmable controller transfer function model, the expression of which is:

[0015] ;

[0016] In the formula, This represents the proportional control coefficient. This represents the proportional control coefficient. Represents the differential control coefficient;

[0017] S45. The transfer function optimizes the parameters of the programmable controller. The specific expression is as follows:

[0018] ;

[0019] S46. The control signal for the power regulator used to control the infrared heating tube is automatically calculated by the programmable controller;

[0020] S5. Adjust the voltage applied to the infrared heating tube by the power regulator based on the control signal, change the output power of the infrared heating tube, and make the actual temperature inside the autoclave consistent with the preset temperature target value.

[0021] Furthermore, the operating modes of the high-pressure reactor in step S1 also include manual control mode and semi-automatic control mode.

[0022] Preferably, the temperature control curve in step S1 is generated during the operation of the autoclave based on the heating slope and the timing period. The heating slope is calculated from the initial temperature, the target temperature and the heating time, and the heating slope is limited to the heating capacity range of the infrared heating tube.

[0023] Preferably, in step S4, the temperature control of each different heating zone operates independently, and the power regulator control signal output by the PID control algorithm in each heating zone is simultaneously input to the two power regulators of the corresponding heating zone to achieve synchronous control of the infrared heating tube in that heating zone.

[0024] Furthermore, step S2 specifically involves the following steps:

[0025] S21. Press the start button on the industrial touch screen to start the fan cooling water pump in sequence under the control of the programmable controller.

[0026] S22. After the cooling water pump of the blower is started, start the stirring blowers of different heating zones in the high-pressure vessel in sequence at intervals.

[0027] S23. After the stirring fan has started, start the power regulators used to control the infrared heating tubes in different heating zones inside the autoclave in turn at intervals.

[0028] S24. Start the air inlet valve on the high pressure vessel. At this time, the high pressure vessel starts to run and heats different heating areas inside the high pressure vessel.

[0029] Furthermore, regarding the operation mode of the autoclave, if manual control mode is adopted, the specific steps are as follows:

[0030] S1. Close the autoclave door, select the autoclave working mode as manual control working mode, and set the working parameters of the autoclave, including target temperature, target pressure and heat preservation and pressure holding time;

[0031] S2. Press the start button to sequentially start the fan, cooling water pump, stirring fan and power regulator of different heating zones in the autoclave, and start the air inlet valve. The autoclave will then start working.

[0032] S3. Monitor the temperature of each heating zone in the autoclave in real time and determine whether the actual temperature of each heating zone is lower than the preset target temperature. If the actual temperature of each heating zone is lower than the preset target temperature, proceed to step S4. If the actual temperature of each heating zone is higher than the preset target temperature, the infrared heating tube of the corresponding heating zone stops heating and proceed to step S5.

[0033] S4. Restart the power regulator of the corresponding heating zone to control the infrared heating tube of the heating zone to continue heating;

[0034] S5. When the pressure inside the autoclave reaches the set value, close the air inlet valve and enter the heat preservation and pressure holding stage. Repeat step S3 during the heat preservation and pressure holding stage until the heat preservation and pressure holding time is reached to complete the preparation of laminated glass.

[0035] Furthermore, regarding the operation mode of the autoclave, if a semi-automatic control mode is adopted, the specific steps are as follows:

[0036] S1. Close the autoclave door, select the autoclave's operating mode as semi-automatic control mode, and set the autoclave's operating parameters;

[0037] S2. Press the start button to sequentially start the fan, cooling water pump, stirring fan and power regulator of different heating zones in the autoclave, and start the air inlet valve. The autoclave will then start working.

[0038] S3. Monitor the temperature of each heating zone in the autoclave in real time and determine whether the actual temperature of each heating zone is lower than the preset target temperature. If the actual temperature of each heating zone is lower than the preset target temperature, proceed to step S4. If the actual temperature of each heating zone is higher than the preset target temperature, the infrared heating tube of the corresponding heating zone stops heating and proceed to step S5.

[0039] S4. Control the power regulator to output full power so that the infrared heating tube in this heating zone continues to heat;

[0040] S5. The temperature control of the heating zone enters the steady-state control stage. At this time, the power regulator controls the infrared heating tube to heat according to the set steady-state temperature.

[0041] S6. When any heating zone in the different heating zones of the autoclave enters steady-state temperature control, the temperature rise trend of that heating zone is predicted according to the set steady-state temperature control cycle. When the steady-state temperature control cycle is reached, it is determined whether the temperature value of the current steady-state temperature control cycle is greater than the recorded value of the previous steady-state temperature control cycle. If the temperature value of the current steady-state temperature control cycle is greater than the recorded value of the previous steady-state temperature control cycle, the infrared heating tube stops heating; if the temperature value of the current steady-state temperature control cycle is less than the recorded value of the previous steady-state temperature control cycle, then step S7 is executed.

[0042] S7. Control the infrared heating tube to continue heating until the actual temperature of each heating zone in the autoclave is equal to the preset target temperature;

[0043] S8. When the pressure inside the autoclave reaches the set value, close the air inlet valve and enter the heat preservation and pressure holding stage. Repeat step S6 during the heat preservation and pressure holding stage until the heat preservation and pressure holding time is reached to complete the preparation of laminated glass.

[0044] Preferably, the operating parameters of the autoclave in step S1 include target temperature, target pressure, heat preservation and pressure holding time, steady-state temperature control cycle, temperature value for entering steady-state temperature control, and power percentage of the heating tube for steady-state temperature control.

[0045] On the other hand, this invention provides a system for a closed-loop automatic temperature control method suitable for laminated glass autoclaves. The system includes an autoclave and a main loop control cabinet for controlling the internal temperature of the autoclave. The internal space of the autoclave is divided into six identical heating zones. Each heating zone is equipped with a stirring fan and a set of infrared heating tubes symmetrical about the central plane of the autoclave. Each infrared heating tube has a temperature sensor on one side, and each side of the infrared heating tube is equipped with a power regulator, enabling independent temperature control of the six heating zones within the autoclave. The main loop control cabinet includes an industrial touchscreen, a programmable controller, an analog input module, a first analog output module, and a second analog output module. The main loop control cabinet is equipped with an industrial touchscreen for setting the autoclave's operating mode, a programmable controller, an analog input module, a first analog output module, and a second analog output module. The analog output modules are all installed in the main circuit control cabinet, and the analog input modules are connected to the temperature sensors. The first and second analog output modules are connected to the power regulators, and the power regulators are connected to the infrared heating tubes. The working mode of the autoclave can be set through the industrial touch screen, and the production process temperature rise curve of the autoclave can be set. The programmable controller can start the stirring fans and infrared heating tubes of each heating zone in sequence according to the set automatic control program. The temperature of each heating zone in the autoclave is collected by the temperature sensor and compared with the set autoclave production process temperature rise curve. At this time, the PID control algorithm in the programmable controller calculates the temperature control quantity according to the temperature deviation and adjusts the output power of the corresponding power regulators of each infrared heating tube, thereby changing the heating energy of the infrared heating tubes and realizing closed-loop automatic control of the autoclave temperature.

[0046] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0047] 1. The temperature closed-loop automatic control method and system for laminated glass autoclaves provided by this invention adopts a novel temperature closed-loop automatic control scheme. The working mode is set via an industrial touchscreen, and the production process temperature rise curve is set. The programmable controller sequentially starts the stirring fan and infrared heating tube according to the designed automatic control program. Temperature sensors collect the temperature of each heating zone in the autoclave and compare it with the set temperature rise curve. The PID control algorithm within the programmable controller calculates the control quantity based on the temperature deviation, adjusts the output power of the power regulator, and thus changes the heating energy of the infrared heating tube, achieving temperature closed-loop control. This improves temperature control accuracy, reduces energy consumption, and increases the yield of laminated glass.

[0048] 2. The temperature closed-loop automatic control method and system for laminated glass autoclaves provided by this invention require no human intervention during operation, greatly reducing the reliance on manual adjustment experience in traditional on / off control methods and improving the adaptability and robustness of temperature control to different operating conditions and external environments. Simultaneously, the proposed method effectively improves the yield of laminated glass, reduces energy consumption, and increases equipment capacity. The proposed method is characterized by intelligence, full automation, and high efficiency, and has significant practical value in the field of electrical automatic control for laminated glass autoclaves. Attached Figure Description

[0049] Figure 1 This is a flowchart of the fully automatic control mode in the closed-loop automatic temperature control method for the autoclave of the present invention;

[0050] Figure 2 This is a flowchart illustrating the heating process for different heating zones within the autoclave in the fully automatic control mode of this invention.

[0051] Figure 3 This is a flowchart of the manual control working mode in the closed-loop automatic temperature control method for the autoclave of the present invention;

[0052] Figure 4 This is a flowchart of the semi-automatic control mode in the closed-loop automatic temperature control method for the autoclave of the present invention.

[0053] Figure 5 This is a schematic diagram of the heating zone of the laminated glass autoclave of the present invention;

[0054] Figure 6 This is a schematic diagram of the hardware composition of the automatic temperature control system for the laminated glass autoclave of the present invention;

[0055] Figure 7 This is a block diagram of the fully automatic control method for the autoclave temperature control of the present invention;

[0056] Figure 8 This is a temperature rise curve diagram of the automatic temperature control method for the autoclave of the present invention;

[0057] Figure 9 This is an enlarged view of the temperature rise error curve of the automatic temperature control method for the autoclave of the present invention.

[0058] Key reference numerals:

[0059] 11. High pressure vessel door; 12. High pressure vessel; 13. Infrared heating tube; 14. Temperature sensor; 15. Stirring fan; 21. Industrial touch screen; 22. Programmable controller; 23. Analog input module; 24. First analog output module; 25. Second analog output module; 26. Power regulator. Detailed Implementation

[0060] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0061] This invention provides a closed-loop automatic temperature control method for laminated glass autoclaves, such as... Figure 1 As shown, it includes the following steps:

[0062] S1. Close the autoclave door 11, set the autoclave 12 to fully automatic control mode via the industrial touch screen 21, and set the autoclave's working parameters, including the target temperature, target pressure and heat preservation and pressure holding time in the autoclave 12 at each stage, and generate a temperature control curve.

[0063] S2. Press the start button, and the pressure vessel 12 will start working, heating different heating areas inside the pressure vessel 12.

[0064] S3. Monitor the temperature of each heating zone inside the autoclave 12 in real time and calculate the temperature deviation between the actual temperature of different heating zones and the preset temperature target value.

[0065] S4. Input the temperature deviation calculated in step S3 into the PID control algorithm. The specific steps are as follows:

[0066] S41. Establish the transfer function model for the temperature control of the autoclave, and its expression is:

[0067] ;

[0068] In the formula, Indicates the switching gain; The time constant represents the first-order inertial element; Indicates the delay time; Represents the Laplace operator; This represents an exponential function.

[0069] S42. Set the output power of the power regulator 26 to full power output, so that the temperature inside the autoclave 12 gradually rises until it remains stable, and record the temperature change data during the heating process of the autoclave 12.

[0070] S43. Using the recorded temperature change data, perform data fitting based on the high-pressure autoclave temperature control transfer function model in step S41 to obtain the parameter values ​​of switching gain, first-order inertial element time constant, and delay time in the transfer function model.

[0071] S44. Treating each heating zone in the autoclave 12 as an independent temperature control loop, establish the transfer function model of the programmable controller 22, the expression of which is:

[0072] ;

[0073] In the formula, This represents the proportional control coefficient. This represents the proportional control coefficient. This represents the differential control coefficient.

[0074] S45. The transfer function optimizes the parameters of the programmable controller 22. The specific expression is as follows:

[0075] ;

[0076] S46. The programmable controller 22 automatically calculates the control signal for the power regulator 26 used to control the infrared heating tube 13.

[0077] S5. Adjust the voltage applied to the infrared heating tube 13 by the power regulator 26 based on the control signal, change the output power of the infrared heating tube 13, and make the actual temperature inside the autoclave 12 consistent with the preset temperature target value.

[0078] In a preferred embodiment, the temperature control curve in step S1 is generated during the operation of the autoclave 12 based on the heating slope and the timing period. The heating slope is calculated from the initial temperature, the target temperature, and the heating time, and the heating slope is limited to the heating capacity range of the infrared heating tube 13.

[0079] In a preferred embodiment, the temperature control of each different heating zone in step S4 operates independently, and the control signal of the power regulator 26 output by the PID control algorithm in each heating zone is simultaneously input to the two power regulators 26 of the corresponding heating zone to achieve synchronous control of the infrared heating tube 13 in that heating zone.

[0080] like Figure 2 As shown, the specific steps of step S2 are as follows:

[0081] S21. Press the start button on the industrial touch screen 21 to start the fan cooling water pump in sequence under the control of the programmable controller 22.

[0082] S22. After the cooling water pump of the blower is started, start the stirring blowers 15 of different heating zones in the high pressure vessel 12 in sequence at intervals.

[0083] S23. After the stirring fan 15 is started, the power regulators 26 used to control the infrared heating tubes 13 in different heating zones inside the high-pressure vessel 12 are started sequentially at intervals.

[0084] S24. Start the air inlet valve on the high pressure vessel 12. At this time, the high pressure vessel 12 starts to run and heats different heating areas inside the high pressure vessel 12.

[0085] In a preferred embodiment, the operating modes of the high-pressure reactor 12 in step S1 also include a manual control mode and a semi-automatic control mode.

[0086] like Figure 3 As shown, the working mode of the autoclave, if the manual control mode is used, the specific steps are as follows:

[0087] S1. Close the autoclave door 11, and set the autoclave 12 to manual control mode via the industrial touch screen 21. Set the working parameters of the autoclave 12, including target temperature, target pressure and heat preservation and pressure holding time.

[0088] S2. Press the start button to sequentially start the fan cooling water pump, stirring fan 15 and power regulator 26 in different heating zones inside the high pressure vessel 12, and start the air inlet valve. The high pressure vessel 12 will then start working.

[0089] S3. Monitor the temperature of each heating zone in the high-pressure vessel 12 in real time and determine whether the actual temperature of different heating zones is less than the preset target temperature. If the actual temperature of different heating zones is less than the preset target temperature, proceed to step S4. If the actual temperature of different heating zones is greater than the preset target temperature, the infrared heating tube 13 of the corresponding heating zone stops heating and proceed to step S5.

[0090] S4. Restart the power regulator 26 of the corresponding heating zone to control the infrared heating tube 13 of the heating zone to continue heating.

[0091] S5. When the gas pressure inside the autoclave 12 reaches the set value, close the air inlet valve and enter the heat preservation and pressure holding stage. Repeat step S3 during the heat preservation and pressure holding stage until the heat preservation and pressure holding time is reached to complete the preparation of laminated glass.

[0092] like Figure 4 As shown, the working mode of the autoclave, if the semi-automatic control mode is adopted, the specific steps are as follows:

[0093] S1. Close the pressure vessel door 11, set the working mode of the pressure vessel 12 to semi-automatic control mode through the industrial touch screen 21, and set the working parameters of the pressure vessel.

[0094] S2. Press the start button to sequentially start the fan cooling water pump, stirring fan 15 and power regulator 26 in different heating zones inside the autoclave, and start the air inlet valve. The autoclave will then begin to work.

[0095] S3. Monitor the temperature of each heating zone in the high-pressure vessel 12 in real time and determine whether the actual temperature of different heating zones is less than the preset target temperature. If the actual temperature of different heating zones is less than the preset target temperature, proceed to step S4. If the actual temperature of different heating zones is greater than the preset target temperature, the infrared heating tube 13 of the corresponding heating zone stops heating and proceed to step S5.

[0096] S4. Control the power regulator 26 to output full power, so that the infrared heating tube 13 in the heating zone continues to heat.

[0097] S5. The temperature control of the heating zone enters the steady-state control stage. At this time, the power regulator controls the infrared heating tube 13 to heat according to the set steady-state temperature.

[0098] S6. When any heating zone in the different heating zones of the autoclave 12 enters steady-state temperature control, the temperature rise trend of that heating zone is predicted according to the set steady-state temperature control cycle. When the steady-state temperature control cycle is reached, it is determined whether the temperature value of the current steady-state temperature control cycle is greater than the recorded value of the previous steady-state temperature control cycle. If the temperature value of the current steady-state temperature control cycle is greater than the recorded value of the previous steady-state temperature control cycle, the infrared heating tube stops heating; if the temperature value of the current steady-state temperature control cycle is less than the recorded value of the previous steady-state temperature control cycle, step S7 is executed.

[0099] S7. Control the infrared heating tube 13 to continue heating until the actual temperature of each heating zone in the autoclave 12 is equal to the preset target temperature.

[0100] S8. When the gas pressure inside the autoclave 12 reaches the set value, close the air inlet valve and enter the heat preservation and pressure holding stage. Repeat step S6 during the heat preservation and pressure holding stage until the heat preservation and pressure holding time is reached to complete the preparation of laminated glass.

[0101] In a preferred embodiment, the operating parameters of the autoclave in step S1 include target temperature, target pressure, heat and pressure holding time, steady-state temperature control cycle, temperature value for entering steady-state temperature control, and percentage of heating tube power for steady-state temperature control.

[0102] On the other hand, the present invention provides a system suitable for a closed-loop automatic temperature control method for laminated glass autoclaves, such as... Figure 5 As shown, it includes a high-pressure vessel 12 and a main circuit control cabinet for controlling the internal temperature of the high-pressure vessel. The internal space of the high-pressure vessel 12 is divided into six identical heating zones. Each heating zone is equipped with a stirring fan 15 and a set of infrared heating tubes 13 symmetrical about the middle plane of the high-pressure vessel 12. Each infrared heating tube 13 is equipped with a temperature sensor 14 on one side, and each infrared heating tube 13 on each side is equipped with a power regulator, so that the temperature of each of the six heating zones in the high-pressure vessel 12 can be independently controlled.

[0103] like Figure 6 and Figure 7 As shown, the main circuit control cabinet includes an industrial touch screen 21 for setting the working mode of the autoclave, a main circuit control cabinet for providing power to the power regulator 26 and the stirring fan 15, a programmable controller 22 for controlling the automatic operation of the autoclave 12, a power regulator 26 for adjusting the heating energy of the infrared heating tube 13, an infrared heating tube 13 for raising the temperature inside the autoclave 12, a stirring fan 15 for uniformizing the temperature inside the autoclave, a temperature sensor 14 for measuring the temperature inside the autoclave, and an analog input module 23, a first analog output module 24, and a second analog output module 25. The main circuit control cabinet is equipped with an industrial touch screen 21 for setting the working mode of the autoclave. The programmable controller 22, the analog input module 23, the first analog output module 24, and the second analog output module 25 are all installed inside the main circuit control cabinet, and the analog input module 23 is connected to the temperature sensor. The first analog output module 24 and the second analog output module 25 are connected to the power regulator 26, which is connected to the infrared heating tube 13. The working mode of the pressure vessel 12 can be set through the industrial touch screen 21, and the production process temperature rise curve of the pressure vessel 12 can be set. The programmable controller can program the controller 22 to start the stirring fan 15 and the infrared heating tube 13 of each heating zone in sequence according to the set automatic control program. The temperature sensor 14 is used to collect the temperature of each heating zone in the pressure vessel 12 and compare it with the set pressure vessel production process temperature rise curve. At this time, the PID control algorithm in the programmable controller 22 can calculate the temperature control quantity according to the temperature deviation and adjust the output power of the power regulator 26 corresponding to each infrared heating tube 14, thereby changing the heating energy of the infrared heating tube 14 and realizing the closed-loop automatic control of the pressure vessel 12 temperature.

[0104] In a preferred embodiment, the industrial touchscreen 21 includes a main screen, a process parameter setting screen, an alarm information screen, and a historical curve screen. The reactor's operating mode can be set to manual, semi-automatic, or fully automatic via the touchscreen, allowing real-time monitoring of the reactor's operating status. The main circuit control cabinet provides power to the agitator 15 and power regulator 26 during system operation. The programmable controller 22 controls the contactors to start and stop the agitator 15, while the power regulator 16's start and stop are determined by control signals output from the programmable controller 22 to its control terminals. The programmable controller 22 contains the complete control program for the operation of the high-pressure reactor 12. This program automatically analyzes and determines the control commands based on the instructions from the industrial touchscreen 21 and the sensor status feedback from the high-pressure reactor 12. The industrial touchscreen 21 and the programmable controller 22 communicate via a serial port for data sharing. The power regulator 26 receives the control signal from the programmable controller 22 and proportionally adjusts the control voltage applied to the infrared heating tube 13 to change the luminous intensity of the infrared heating tube, thereby changing the heating power.

[0105] Example:

[0106] This embodiment uses Figure 5 The high-pressure vessel shown is the controlled object, and its interior is divided into 6 heaters, designed as follows: Figure 6 and Figure 7 The control system shown was used to test the control effect of the fully automatic control method. A step signal was used as input, and the target temperature was set to 65℃. The fully automatic control method used a PID control algorithm to control the infrared heating tubes in six zones to heat the autoclave. The temperature rise curve for each zone is shown below. Figure 8 As shown. A magnified view of the steady-state error curve, as shown. Figure 9 As shown in the figure, under the control of the automatic control method, the steady-state error of each heating zone can be kept within ±1℃, which shows high temperature control accuracy.

[0107] This invention employs a novel closed-loop automatic temperature control scheme. The operating mode is set via an industrial touchscreen, and the production process temperature rise curve is defined. A programmable controller (PCC) sequentially activates the stirring fan and infrared heating tube according to the designed automatic control program. Temperature sensors collect the temperature of each heating zone within the autoclave and compare it with the set temperature rise curve. The PCC's PID control algorithm calculates the control quantity based on the temperature deviation, adjusts the power regulator output power, and thus changes the heating energy of the infrared heating tube, achieving closed-loop temperature control. This improves temperature control accuracy, reduces energy consumption, and increases the yield of laminated glass. The proposed method requires no human intervention during operation, significantly reducing the reliance on manual adjustment experience in traditional on / off control methods. It also improves the adaptability of the control method to different operating conditions and external environments, and enhances the robustness of temperature control. The proposed method effectively improves the yield of laminated glass, reduces energy consumption, and increases equipment capacity, demonstrating significant practical value in the field of automatic electrical control for laminated glass autoclaves.

[0108] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A temperature closed-loop automatic control method suitable for a laminated glass autoclave, characterized in that: It comprises the following steps: S1, close the autoclave door, select the working mode of the autoclave as full-automatic control mode, set the working parameters of the autoclave, and generate a temperature control curve; S2, press the start button, the autoclave starts to work, and different heating areas in the autoclave are heated; S3, the temperature of each heating area in the autoclave is monitored in real time, and the temperature deviation between the actual temperature and the preset temperature target value of different heating areas is calculated; S4, the temperature deviation calculated in step S3 is input into the PID control algorithm, and the specific steps are as follows: S41, a temperature control transfer function model of the autoclave is established, and its expression is: ； wherein denotes the switching gain; denotes the time constant of the first order inertial element; denotes the delay time; denotes the Laplace operator; denotes the exponential function; S42, set the output power of the power regulator to full power output, so that the temperature in the autoclave gradually rises until it stabilizes, and record the temperature change data during the heating process of the autoclave; S43, using the recorded temperature change data, according to the autoclave temperature control transfer function model in step S41, data fitting is performed to obtain the parameter values of the switching gain, the first-order inertia time constant and the delay time in the transfer function model; S44, each heating area in the autoclave is regarded as an independent temperature control loop, and a programmable controller transfer function model is established, and its expression is: ； wherein represents a proportional control coefficient, represents a proportional control coefficient, represents a differential control coefficient; S45, the transfer function optimizes the parameters of the programmable controller, and the specific expression is: ； S46, the programmable controller automatically calculates the control signal of the power regulator for controlling the infrared heating tube; S5, based on the control signal, adjust the voltage applied to the infrared heating tube by the power regulator, change the output power of the infrared heating tube, so that the actual temperature in the autoclave is consistent with the preset temperature target value.

2. The temperature closed-loop automatic control method suitable for the laminated glass autoclave according to claim 1, characterized in that: The working mode of the autoclave in step S1 also includes manual control mode and semi-automatic control mode.

3. The temperature closed-loop automatic control method suitable for the laminated glass autoclave according to claim 1, characterized in that: The temperature control curve in step S1 is generated during the operation of the autoclave according to the temperature rise slope and the timing period, the temperature rise slope is calculated from the initial temperature, the target temperature and the temperature rise time, and the temperature rise slope is limited within the heating capacity range of the infrared heating tube.

4. The temperature closed-loop automatic control method suitable for the laminated glass autoclave according to claim 1, characterized in that: In step S4, the temperature control of each different heating area is independently operated, and the power regulator control signal output by the PID control algorithm in each heating area is simultaneously input into the two power regulators of the corresponding heating area to realize synchronous control of the infrared heating tube in the heating area.

5. The temperature closed-loop automatic control method suitable for the laminated glass autoclave of claim 1, wherein: The specific steps of step S2 are as follows: S21, press the start button on the industrial touch screen, and start the fan and water pump under the control of the programmable controller; S22, after the fan and water pump are started, the stirring fans in different heating areas in the autoclave are started in sequence and at intervals; S23, after the stirring fans are started, the power regulators for controlling the infrared heating tubes in different heating areas in the autoclave are started in sequence and at intervals; S24, start the air inlet valve on the autoclave, at which time the autoclave starts to work and heats different heating areas in the autoclave.

6. The temperature closed-loop automatic control method suitable for the laminated glass autoclave of claim 2, wherein: If the manual control mode is adopted for the working mode of the autoclave, the specific steps are as follows: S1, close the autoclave door, select the working mode of the autoclave as a manual control mode, and set the working parameters of the autoclave, the working parameters including a target temperature, a target pressure and a holding time; S2, press the start button, and start the fan cooling water pump, the stirring fan and the power regulator of different heating zones in the autoclave in sequence, start the air inlet valve, and the autoclave starts to work; S3, monitor the temperature of each heating zone in the autoclave in real time, judge whether the actual temperature of different heating zones is less than the preset target temperature, if the actual temperature of different heating zones is less than the preset target temperature, execute step S4; if the actual temperature of different heating zones is greater than the preset target temperature, the infrared heating tube of the corresponding heating zone stops heating at this time, and step S5 is executed; S4, start the power regulator of the corresponding heating zone again to control the infrared heating tube of the heating zone to continue heating; S5, when the air pressure in the autoclave reaches the set value, the air inlet valve is closed, and the holding stage is entered, and step S3 is repeated in the holding stage until the holding time reaches, and the preparation of the laminated glass is completed.

7. The temperature closed-loop automatic control method suitable for the laminated glass autoclave of claim 2, wherein: The working mode of the autoclave, if a semi-automatic control mode is adopted, the specific steps are as follows: S1, close the autoclave door, select the working mode of the autoclave as a semi-automatic control mode, and set the working parameters of the autoclave; S2, press the start button, and start the fan cooling water pump, the stirring fan and the power regulator of different heating zones in the autoclave in sequence, start the air inlet valve, and the autoclave starts to work; S3, monitor the temperature of each heating zone in the autoclave in real time, judge whether the actual temperature of different heating zones is less than the preset target temperature, if the actual temperature of different heating zones is less than the preset target temperature, execute step S4; if the actual temperature of different heating zones is greater than the preset target temperature, the infrared heating tube of the corresponding heating zone stops heating at this time, and step S5 is executed; S4, control the power regulator to output full power, so that the infrared heating tube of the heating zone continues to heat; S5, the temperature control of the heating zone enters a steady state control stage, at this time the power regulator controls the infrared heating tube to heat according to the set steady state temperature; S6, when any one of the different heating zones in the autoclave enters the steady state temperature control, the temperature rising trend of the heating zone is predicted according to the set steady state temperature control period, when the steady state temperature control period reaches, judge whether the temperature value of the current steady state temperature control period is greater than the record value of the last steady state temperature control period, if the temperature value of the current steady state temperature control period is greater than the record value of the last steady state temperature control period, the infrared heating tube stops heating; if the temperature value of the current steady state temperature control period is less than the record value of the last steady state temperature control period, step S7 is executed; S7, control the infrared heating tube to continue heating until the actual temperature of each heating zone in the autoclave is equal to the preset target temperature; S8, when the air pressure in the autoclave reaches the set value, the air inlet valve is closed, and the holding stage is entered, and step S6 is repeated in the holding stage until the holding time reaches, and the preparation of the laminated glass is completed.

8. The temperature closed-loop automatic control method suitable for the laminated glass autoclave according to claim 7, characterized in that: The working parameters of the autoclave in step S1 include a target temperature, a target pressure, a holding and pressure maintaining time, a steady state temperature control period, a temperature value entering the steady state temperature control, and a steady state temperature control heating tube power percentage.

9. A system for the automatic closed-loop temperature control method of claim 1 to 8, characterized in that it comprises: It comprises an autoclave and a main loop control cabinet for controlling the temperature inside the autoclave, The internal space of the autoclave is divided into six identical heating zones, each of which is provided with a stirring fan and a set of infrared heating pipes symmetric about the middle plane of the autoclave. Each infrared heating pipe is provided with a temperature sensor on one side, and each side of the infrared heating pipe is provided with a power regulator, so that the six heating zones in the autoclave can realize independent temperature control. The main loop control cabinet comprises an industrial touch screen, an editable controller, an analog input module, a first analog output module and a second analog output module. The industrial touch screen is provided on the main loop control cabinet for setting the working mode of the autoclave. The editable controller, the analog input module, the first analog output module and the second analog output module are installed in the main loop control cabinet, and the analog input module is connected with the temperature sensor, the first analog output module and the second analog output module are connected with the power regulator respectively, and the power regulator is connected with the infrared heating pipe. The working mode of the autoclave can be set through the industrial touch screen, and the production process temperature rising curve of the autoclave can be set. The programmable controller starts the stirring fan and the infrared heating pipe of each heating zone in turn according to the set automatic control program. The temperature of each heating zone in the autoclave is collected by the temperature sensor and compared with the set production process temperature rising curve of the autoclave. At this time, the PID control algorithm in the programmable controller calculates the temperature control amount according to the temperature deviation, and adjusts the output power of the corresponding power regulator of each infrared heating pipe, thereby changing the heating energy of the infrared heating pipe, realizing the closed loop automatic control of the temperature of the autoclave.

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