A distributed collaborative control method for multi-temperature-zone temperature field of hot air tunnel furnace

Abstract

This invention provides a distributed collaborative control method for the temperature field of multiple temperature zones in a hot blast tunnel furnace, relating to the field of automatic control technology for industrial heating equipment. The method includes the following steps: dividing the hot blast tunnel furnace into multiple independent control temperature zones and establishing an industrial Ethernet distributed communication network to obtain physical parameter data; identifying the step response of each independent control temperature zone based on the physical parameter data to obtain dynamic parameters and cross-coupling parameters, and obtaining temperature zone characteristic data; setting a virtual leader agent based on the temperature zone characteristic data, generating an S-shaped target trajectory and tuning the collaborative control parameters; and performing consistent collaborative adjustment based on the response phase according to the collaborative control parameters, so that the response phase of each independent control temperature zone synchronously approaches the S-shaped target trajectory, obtaining the collaborative control correction amount.

Description

Technical Field

[0001] This invention relates to the field of automatic control technology for industrial heating equipment, and more specifically, to a distributed collaborative control method for the temperature field of multiple temperature zones in a hot air tunnel furnace. Background Technology

[0002] As a core piece of equipment in continuous heat treatment processes, the quality of coordinated temperature field control across multiple temperature zones in a hot air tunnel oven directly determines the baking, drying, or curing quality of the product. Existing technologies divide the measured temperature at each measurement point by its corresponding final target temperature to obtain a normalized measured temperature value. The average of all normalized measured temperatures is then used as a reference benchmark. The correction gain for each temperature zone is determined by calculating the deviation between each normalized measured temperature and the reference benchmark, along with its differential value. Finally, the correction gain is used to revise the target temperature of each temperature zone to achieve synchronization of the response behavior of each zone.

[0003] The normalization deviation correction strategy takes the convergence of temperature values ​​in each temperature zone as the control objective. It fails to distinguish between two fundamentally different operating conditions: one where the temperature rises too slowly and requires increased energy injection, and the other where the temperature rises too quickly and requires suppression of overshoot risk. Its coordination logic is based on the quantitative analysis of the degree of temperature deviation at the current moment, rather than on the judgment of the position of each temperature zone in the entire heating process. Therefore, it is difficult to achieve dynamic synchronization of each temperature zone throughout the heating process.

[0004] The continuous entry of cold material at the inlet of a tunnel furnace generates a persistent thermal front disturbance that propagates along the material's direction of travel within the furnace. Current solutions lack explicit utilization of the thermal front propagation speed and attenuation characteristics; feedforward compensation for each temperature zone relies on a single input signal from the inlet sensor, failing to establish a proactive adjustment mechanism based on propagation characteristics. To address these issues, this invention integrates the control of the temperature field across multiple temperature zones of the hot blast tunnel furnace into a joint architecture of response phase synchronization and thermal front propagation timing compensation. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention is proposed. A first aspect of this invention provides a distributed collaborative control method for the temperature field of a multi-temperature zone in a hot blast tunnel furnace, comprising the following specific steps: The hot air tunnel furnace is divided into multiple independent temperature control zones and an industrial Ethernet distributed communication network is established to obtain physical parameter data. Based on physical parameter data, step response identification is performed on each independent control temperature zone to obtain dynamic parameters and cross-coupling parameters, and temperature zone characteristic data is obtained. Based on temperature zone characteristic data, a virtual leader intelligent agent is set up to generate an S-shaped target trajectory and adjust the collaborative control parameters. Based on the coordinated control parameters, consistent coordinated adjustment based on response phase is performed so that the response phase of each independent control temperature zone synchronously approaches the S-shaped target trajectory, thus obtaining the coordinated control correction amount; Based on the collaborative control correction amount and combined with the initial state information of the material, a time-series feedforward compensation based on the propagation of the thermal front is performed to obtain a comprehensive control command; The heating element, circulating fan and damper actuator are adjusted based on the integrated control command, and temperature data is collected to obtain feedback data. A two-dimensional temperature field is constructed based on the feedback data and the temperature field evaluation index is calculated to obtain the temperature field evaluation result. Based on the temperature field evaluation results, the weights of consistency coordination and timing feedforward compensation are adjusted, and the temperature zone characteristic data is corrected to obtain updated temperature zone characteristic data. The coordination control parameters are updated according to the updated temperature zone characteristic data for cyclic control, forming a closed-loop coordination control process for the multi-temperature zone temperature field of the hot blast tunnel furnace.

[0006] Preferably, the process of dividing the hot air tunnel furnace into multiple independent temperature control zones and establishing an industrial Ethernet distributed communication network to obtain physical parameter data includes: The furnace chamber of the hot air tunnel furnace is divided into N independent temperature control zones along the material travel direction. Each independent temperature control zone is equipped with a heating element, a circulating fan, a damper actuator, a temperature sensor array and a controller. Heat insulation partitions are installed between each adjacent independent temperature control zone. A material initial temperature detection device and a material category identification sensor are deployed at the entrance of the hot air tunnel furnace. Based on the division and configuration of each independent control temperature zone of the hot air tunnel furnace, the controllers of each independent control temperature zone are connected to the same industrial Ethernet to establish an industrial Ethernet distributed communication network. Based on the industrial Ethernet distributed communication network, the parameters of each mechanism configured in each independent control temperature zone are summarized to obtain physical parameter data.

[0007] Preferably, the step response identification of each independent control temperature zone based on physical parameter data, obtaining dynamic parameters and cross-coupling parameters, and obtaining temperature zone characteristic data includes: After the hot air tunnel furnace is run to a stable initial operating condition, a step increment is applied to the heating power of each independent control temperature zone, and the temperature response data of each temperature measuring point in the temperature sensor array inside each independent control temperature zone is recorded simultaneously until each independent control temperature zone re-enters a steady state, and the step response curve of each independent control temperature zone is obtained. Calculate the gain coefficient, time constant, and pure time delay of each independent control temperature zone based on the step response curve of each independent control temperature zone. During the process of applying a step increment to the heating power of each independent control temperature zone, the temperature fluctuation data of the independent control temperature zone adjacent to the independent control temperature zone are recorded simultaneously, and the cross-coupling gain coefficient between the adjacent independent control temperature zones is calculated based on the recorded temperature fluctuation data of the adjacent independent control temperature zones. The gain coefficient, time constant, and pure time delay of each independent control temperature zone, as well as the cross-coupling gain coefficient between adjacent independent control temperature zones, are summarized into temperature zone characteristic data.

[0008] Preferably, the step of setting up a virtual leader agent based on temperature zone characteristic data, generating an S-shaped target trajectory, and tuning collaborative control parameters includes: Based on the gain coefficient and pure lag time of each independent control temperature zone in the temperature zone characteristic data, an S-shaped dynamic curve of a virtual leader agent is set as the ideal temperature trajectory of the virtual leader agent according to the baking or drying process requirements. Based on the S-shaped dynamic curve of the virtual leader agent and the gain coefficient and pure lag time of each independent control temperature zone in the temperature zone characteristic data, the feedforward compensation coefficient and consistency feedback gain of each independent control temperature zone agent are tuned. The S-shaped dynamic curve of the virtual leader agent and the feedforward compensation coefficient and consistency feedback gain after tuning of each independent control temperature zone agent are summarized into cooperative control parameters.

[0009] Preferably, the consistent coordinated adjustment based on response phase performed according to the coordinated control parameters, so that the response phase of each independent control temperature zone synchronously approaches the S-shaped target trajectory, and the resulting coordinated control correction includes: Based on the collaborative control parameters, each independent temperature zone agent reads its current measured temperature value and the S-shaped target trajectory of the virtual leader agent in each control cycle, and calculates the current heating progress percentage of each independent temperature zone agent from the initial temperature to the target temperature. The current heating process percentage is mapped to a phase range of 0° to 180° to serve as the response phase state quantity for each independent temperature control agent; Based on the response phase state quantity of each independent temperature control agent, the response phase state quantity of each independent temperature control agent is compared with the response phase state quantity of the adjacent independent temperature control agents, so that the response phase state quantity of each independent temperature control agent synchronously approaches the S-shaped target trajectory of the virtual leader agent. During the process of synchronizing the response phase state of each independent control temperature zone agent with the S-shaped target trajectory of the virtual leader agent, the control adjustment amount generated by each independent control temperature zone agent is summarized as the cooperative control correction amount.

[0010] Preferably, the comprehensive control command obtained by performing time-series feedforward compensation based on thermal front propagation, combined with the initial state information of the material and the collaborative control correction amount, includes: Based on the collaborative control correction amount, the initial material temperature value is obtained through the material initial temperature detection device deployed at the inlet of the hot air tunnel furnace; Material category information is obtained by a material category identification sensor deployed at the entrance of the hot air tunnel furnace, and the initial temperature value and material category information of the material are summarized into the initial state information of the material. Based on the initial state information of the material and the collaborative control correction amount, the heat compensation amount required for each independent control temperature zone is determined according to the initial temperature value of the material and the material category information, and used as the timing feedforward compensation amount. The collaborative control correction amount and the timing feedforward compensation amount are combined to obtain the comprehensive control command for each independent control temperature zone.

[0011] Preferably, the step of adjusting the heating element, circulating fan, and damper actuator based on integrated control commands, and collecting temperature data to obtain feedback data includes: Based on the integrated control command, the heating power adjustment, circulating fan speed adjustment, and damper opening adjustment in the integrated control command are sent to the heating element, circulating fan, and damper actuator respectively through the industrial Ethernet distributed communication network; Based on the heating power adjustment amount, circulating fan speed adjustment amount, and damper opening adjustment amount issued to the heating element, circulating fan, and damper actuator, the heating element, circulating fan, and damper actuator respectively perform heating power adjustment action, circulating fan speed adjustment action, and damper opening adjustment action; After performing actions such as adjusting heating power, regulating circulating fan speed, and adjusting damper opening, temperature data for each independent control temperature zone is collected through a temperature sensor array and used as feedback data.

[0012] Preferably, the step of constructing a two-dimensional temperature field using feedback data and calculating temperature field evaluation indicators to obtain temperature field evaluation results includes: Based on the temperature values ​​of each temperature measuring point in the temperature sensor array within each independent control temperature zone in the feedback data, the temperature values ​​of each temperature measuring point in the temperature sensor array within each independent control temperature zone are spatially interpolated according to the installation position coordinates of each temperature measuring point in the temperature sensor array within each independent control temperature zone to obtain a two-dimensional temperature field distribution map of the hot air tunnel furnace. Based on the two-dimensional temperature field distribution map of the hot air tunnel furnace, the temperature difference between each temperature measuring point in the temperature sensor array within each independent control temperature zone is taken as the transverse temperature difference within each independent control temperature zone, the temperature difference between each temperature measuring point at the adjacent boundary of adjacent independent control temperature zones is taken as the longitudinal temperature difference between adjacent independent control temperature zones, and the variance of the temperature values ​​at all locations in the two-dimensional temperature field distribution map of the hot air tunnel furnace is taken as the overall uniformity coefficient of the temperature field. The lateral temperature difference within each independent control temperature zone, the longitudinal temperature difference between adjacent independent control temperature zones, and the overall uniformity coefficient of the temperature field are summarized as the temperature field evaluation results.

[0013] Preferably, the step of adjusting the weights of consistency coordination and time-series feedforward compensation based on the temperature field evaluation results, and correcting the temperature region characteristic data to obtain updated temperature region characteristic data includes: Based on the transverse temperature difference within each independent control temperature zone, the longitudinal temperature difference between adjacent independent control temperature zones, and the overall uniformity coefficient of the temperature field in the temperature field evaluation results; The transverse temperature difference within each independent control temperature zone, the longitudinal temperature difference between adjacent independent control temperature zones, and the overall uniformity coefficient of the temperature field are compared with their respective preset thresholds. Based on the comparison results, the weights of consistency coordination adjustment and timing feedforward compensation are adjusted. Based on the transverse temperature difference within each independent control temperature zone and the longitudinal temperature difference between adjacent independent control temperature zones in the temperature field evaluation results, the gain coefficient, time constant, and pure lag time in the temperature zone characteristic data of the independent control temperature zones whose transverse temperature difference within each independent control temperature zone and the longitudinal temperature difference between adjacent independent control temperature zones exceed their respective preset thresholds are corrected. The gain coefficient, time constant, and pure time delay in the corrected individual control temperature zone characteristic data, as well as the gain coefficient, time constant, and pure time delay in the uncorrected individual control temperature zone characteristic data, are combined to form the updated temperature zone characteristic data.

[0014] Preferably, the step of updating the collaborative control parameters based on the updated temperature zone characteristic data and performing cyclic control to form a closed-loop collaborative control process for the multi-temperature zone temperature field of the hot blast tunnel furnace includes: Based on the gain coefficient, time constant, and pure time delay of each independent control temperature zone in the updated temperature zone characteristic data, the feedforward compensation coefficient and consistency feedback gain of each independent control temperature zone agent are readjusted to obtain the updated cooperative control parameters. Based on the updated collaborative control parameters, the operation of consistent collaborative adjustment based on the response phase is returned to perform based on the collaborative control parameters, forming a closed-loop collaborative control process for the temperature field of the multi-temperature zone of the hot blast tunnel furnace.

[0015] Compared with existing technologies, the distributed collaborative control method for the multi-temperature zone temperature field of a hot blast tunnel furnace provided by this invention uses the response phase rather than the temperature deviation amplitude as the basis for consistent collaborative adjustment, so that the control decision of each temperature zone is directly related to its position in the entire heating process. This fundamentally overcomes the problem of misjudgment of operating conditions caused by the normalized deviation correction strategy using the same gain allocation logic in the initial heating and deceleration stages. By combining the initial state information of the material with the heat compensation amount predicted by each temperature zone based on model parameters, and by using the propagation characteristics of the hot front along the furnace length to establish a forward-looking time-series feedforward compensation mechanism for the downstream temperature zone, the generation of comprehensive control commands carries the phase information of the arrival time of the hot front wavefront. This breaks through the limitation of existing schemes that rely on a single inlet sensor signal for a posteriori compensation. By constructing a two-dimensional temperature field through feedback data and calculating the temperature field evaluation index, the consistent collaborative adjustment weight and the time-series feedforward compensation weight are adjusted simultaneously based on the evaluation results, and the temperature zone characteristic data are corrected. This makes the entire control process form a closed-loop collaborative control architecture with parameter self-correction capability in both the synchronous heating process and the hot front propagation compensation dimensions. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. In the drawings: Figure 1 This is a flowchart of a distributed collaborative control method for the temperature field of a multi-temperature zone in a hot blast tunnel furnace according to an embodiment of the present invention. Detailed Implementation

[0017] Hereinafter, exemplary embodiments according to the present invention will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of the present invention, and not all embodiments of the present invention. It should be understood that the present invention is not limited to the exemplary embodiments described herein.

[0018] As mentioned in the background section, the normalization deviation correction strategy takes the convergence of temperature values ​​in each temperature zone as the control objective. It fails to distinguish between two fundamentally different operating conditions: one where the temperature rises too slowly and requires increased energy injection, and the other where the temperature rises too quickly and requires suppression of overshoot risk. Its coordination logic is based on the quantitative analysis of the degree of temperature deviation at the current moment, rather than on the judgment of the position of each temperature zone in the entire heating process. Therefore, it is difficult to achieve dynamic synchronization of each temperature zone throughout the heating process.

[0019] Figure 1A flowchart of a distributed collaborative control method for the temperature field of a multi-temperature zone in a hot blast tunnel furnace according to an embodiment of the present invention is shown, including the following specific steps: S1: Divide the hot air tunnel furnace into multiple independent temperature control zones and establish an industrial Ethernet distributed communication network to obtain physical parameter data.

[0020] In step S1, the furnace chamber of the hot air tunnel furnace is divided into N independent temperature control zones along the material travel direction. Each independent temperature control zone is equipped with a heating element, a circulating fan, a damper actuator, a temperature sensor array, and a controller. Heat insulation partitions are installed between adjacent independent temperature control zones. An initial material temperature detection device and a material category identification sensor are deployed at the entrance of the hot air tunnel furnace.

[0021] Furthermore, along the material travel direction, the hot blast tunnel furnace is divided into N independently controlled temperature zones according to the arrangement of heating elements on the top and side walls of the furnace and the spatial distribution of hot blast circulation components in each section of the furnace. The value of N is determined based on the total length of the hot blast tunnel furnace and the number of heating element groups. Each independently controlled temperature zone occupies a continuous interval along the length of the furnace. Each independently controlled temperature zone is equipped with an independent heating element as the heat supply actuator for that temperature zone, an independent circulating fan as the power actuator for hot blast circulation within that temperature zone, and an independent damper actuator as the air supply direction and air supply mechanism for that temperature zone. The quantity adjustment actuator is configured with a temperature sensor array containing multiple temperature measurement points as the acquisition mechanism for multi-point temperature signals in this temperature zone. An independent controller is configured as the calculation and issuance mechanism for control commands in this temperature zone. Insulation baffles are installed at the furnace partition walls between adjacent independent control temperature zones to reduce the amount of uncontrolled heat exchange between adjacent independent control temperature zones through furnace wall conduction and thermal radiation. An initial material temperature detection device is deployed at the entrance of the hot air tunnel furnace to obtain the initial temperature value of the material entering the furnace. A material category identification sensor is deployed at the entrance of the hot air tunnel furnace to obtain the type and specification information of the material entering the furnace.

[0022] Based on the division and configuration of each independent control temperature zone of the hot air tunnel furnace, the controllers of each independent control temperature zone are connected to the same industrial Ethernet to establish an industrial Ethernet distributed communication network. Based on the industrial Ethernet distributed communication network, the parameters of each mechanism configured in each independent control temperature zone are summarized to obtain physical parameter data.

[0023] Furthermore, based on the division and configuration results of each independent control temperature zone of the hot blast tunnel furnace, the controllers configured in each independent control temperature zone are connected to the same industrial Ethernet network through an industrial Ethernet communication interface. An industrial Ethernet communication protocol stack is configured in each controller so that each controller can send and receive data packets with each other through the industrial Ethernet network, thereby establishing an industrial Ethernet distributed communication network covering all controllers in the independent control temperature zones. After the industrial Ethernet distributed communication network is established, the rated power and rated voltage values ​​of the heating elements configured in each independent control temperature zone, the rated speed and rated air volume values ​​of the circulating fans configured in each independent control temperature zone, the opening stroke range and response time values ​​of the damper actuators configured in each independent control temperature zone, the total number of temperature measuring points of the temperature sensor array configured in each independent control temperature zone and the specific installation coordinates of each temperature measuring point inside the furnace, the temperature detection range and detection accuracy values ​​of the initial material temperature detection device, and the list of material categories that the material category identification sensor can identify are summarized into physical parameter data.

[0024] S2: Based on the physical parameter data, perform step response identification on each independent control temperature zone, obtain dynamic parameters and cross-coupling parameters, and obtain temperature zone characteristic data.

[0025] In step S2, after the hot air tunnel furnace is run to a stable initial operating condition, a step increment is applied to the heating power of each independent control temperature zone, and the temperature response data of each temperature measuring point in the temperature sensor array inside each independent control temperature zone is recorded simultaneously until each independent control temperature zone re-enters a steady state, and the step response curve of each independent control temperature zone is obtained.

[0026] Furthermore, all heating elements and circulating fans of the hot blast tunnel furnace are put into operation to stabilize the temperature of each independent control temperature zone inside the furnace for a preset duration to establish a stable initial operating condition. After the stable initial operating condition is established, the first independent control temperature zone is selected as the current test temperature zone. A step increment is applied to the heating power of the current test temperature zone and kept constant. At the same time as applying the step increment, the temperature data recording operation of all temperature measurement points in the temperature sensor array inside the current test temperature zone is started. The temperature data of each temperature measurement point is continuously recorded until the temperature value of each temperature measurement point inside the current test temperature zone re-enters a stable state and no longer changes beyond the preset fluctuation range. After confirming that the current test temperature zone has re-entered a steady state, the temperature data recording operation is stopped, and the temperature change data of each temperature measurement point over time recorded throughout the process is summarized into the step response curve of the current test temperature zone. The above operation is performed sequentially for each independent control temperature zone to apply the step increment and record the temperature data until all independent control temperature zones have been tested, and the step response curve of each independent control temperature zone is obtained.

[0027] The gain coefficient, time constant, and pure time delay of each independent control temperature zone are calculated based on the step response curve of each independent control temperature zone.

[0028] Furthermore, the steady-state temperature change of each independent control temperature zone is obtained by subtracting the initial temperature value from the steady-state temperature value. Based on the step response curve of each independent control temperature zone, the moment when the temperature response value of each independent control temperature zone first deviates from the initial temperature value from the moment the step increment is applied is determined, and the time length between this moment and the moment the step increment is applied is taken as the pure lag time of each independent control temperature zone. Based on the step response curve of each independent control temperature zone, the time value corresponding to the temperature response value of each independent control temperature zone reaching 63.2% of the steady-state temperature change from the moment the step increment is applied is determined, and the time length obtained by subtracting the pure lag time from this time value is taken as the time constant of each independent control temperature zone. The gain coefficient of each independent control temperature zone is obtained by dividing the steady-state temperature change of each independent control temperature zone by the amplitude of the step increment of the heating power applied to that independent control temperature zone.

[0029] Gain coefficient calculation formula: ; in, For the first Gain coefficient for each independently controlled temperature zone For the first The difference between the steady-state temperature of each independently controlled temperature zone after re-entering steady state in the step response test and the initial temperature before the step response test. For the first The magnitude of the step increment of heating power applied to each independently controlled temperature zone.

[0030] During the process of applying a step increment to the heating power of each independent control temperature zone, the temperature fluctuation data of the independent control temperature zone adjacent to the independent control temperature zone are recorded simultaneously, and the cross-coupling gain coefficient between the adjacent independent control temperature zones is calculated based on the recorded temperature fluctuation data of the adjacent independent control temperature zones. Furthermore, during the application of a step increment to the heating power of the current test temperature zone, the temperature fluctuation data recording operation of all temperature measurement points in the temperature sensor array within the independent control temperature zone adjacent to the current test temperature zone is simultaneously initiated. The temperature fluctuation data of each temperature measurement point in the adjacent independent control temperature zones is continuously recorded until the current test temperature zone re-enters a steady state. After recording stops, the maximum and minimum values ​​of the temperature fluctuations are extracted from the recorded temperature fluctuation data of the adjacent independent control temperature zones. The maximum temperature change of the adjacent independent control temperature zone is obtained by subtracting the minimum temperature change from the maximum value. The cross-coupling gain coefficient between the current test temperature zone and the adjacent independent control temperature zone is obtained by dividing the maximum temperature change of the adjacent independent control temperature zone by the amplitude of the step increment applied to the heating power of the current test temperature zone. Following the above operation, during the application of the step increment to each independent control temperature zone in sequence, the temperature fluctuation data of all adjacent independent control temperature zones of each independent control temperature zone are simultaneously recorded, and the cross-coupling gain coefficient between each independent control temperature zone and all its adjacent independent control temperature zones is calculated.

[0031] Formula for the cross-coupling gain coefficient between adjacent independent control temperature zones: ; in, For the first Each independent temperature control zone and the first Cross-coupling gain coefficient between independent control temperature zones For the first The independently controlled temperature zone is in the first The maximum temperature change recorded in the temperature fluctuation data during a step increment of heating power applied to an independent temperature control zone. For the first The magnitude of the step increment of heating power applied to each independently controlled temperature zone.

[0032] ; in, For the first Each independent temperature control zone and the first Cross-coupling gain coefficient between independent control temperature zones For the first The independently controlled temperature zone is in the first The maximum temperature change recorded in the temperature fluctuation data during a step increment of heating power applied to an independent temperature control zone. For the first The magnitude of the step increment of heating power applied to each independently controlled temperature zone.

[0033] The gain coefficient, time constant, and pure time delay of each independent control temperature zone, as well as the cross-coupling gain coefficient between adjacent independent control temperature zones, are summarized into temperature zone characteristic data.

[0034] Furthermore, the gain coefficient of each independent control temperature zone, the time constant of each independent control temperature zone, the pure time delay of each independent control temperature zone, and the cross-coupling gain coefficient between each independent control temperature zone and all its adjacent independent control temperature zones are summarized into temperature zone characteristic data.

[0035] S3: Based on temperature zone characteristic data, set up a virtual leader intelligent agent, generate an S-shaped target trajectory, and adjust the collaborative control parameters.

[0036] In step S3, based on the gain coefficient and pure lag time of each independent control temperature zone in the temperature zone characteristic data, an S-shaped dynamic curve of a virtual leader agent is set as the ideal temperature trajectory of the virtual leader agent according to the baking or drying process requirements.

[0037] Furthermore, based on the gain coefficient and pure lag time of each independent control temperature zone in the temperature zone characteristic data, an S-shaped dynamic curve is set as the ideal temperature trajectory of the virtual leader agent according to the target temperature value and heating time requirements in the baking or drying process. The starting point temperature value of the S-shaped dynamic curve is equal to the initial temperature value of each independent control temperature zone before the hot air tunnel oven starts heating, and the ending temperature value of the S-shaped dynamic curve is equal to the target temperature value in the baking or drying process requirements. The rising segment of the S-shaped dynamic curve consists of the first heating rate in the initial stage and the second heating rate when approaching the ending temperature, with the first heating rate being greater than the second heating rate.

[0038] Based on the S-shaped dynamic curve of the virtual leader agent and the gain coefficient and pure lag time of each independent control temperature zone in the temperature zone characteristic data, the feedforward compensation coefficient and consistency feedback gain of each independent control temperature zone agent are tuned.

[0039] Furthermore, based on the S-shaped dynamic curve of the virtual leader agent and the gain coefficient and pure lag time of each independent control temperature zone in the temperature zone characteristic data, the gain coefficient and pure lag time of each independent control temperature zone are substituted into the tuning rules of the feedforward compensation coefficient to determine the feedforward compensation coefficient of each independent control temperature zone agent. The gain coefficient and pure lag time of each independent control temperature zone are substituted into the tuning rules of the consistency feedback gain to determine the consistency feedback gain of each independent control temperature zone agent. The tuning rule of the feedforward compensation coefficient is that the feedforward compensation coefficient is inversely proportional to the gain coefficient and directly proportional to the pure lag time. The tuning rule of the consistency feedback gain is that the consistency feedback gain is inversely proportional to the gain coefficient and inversely proportional to the pure lag time.

[0040] The S-shaped dynamic curve of the virtual leader agent and the feedforward compensation coefficient and consistency feedback gain after tuning of each independent control temperature zone agent are summarized into cooperative control parameters.

[0041] Furthermore, the temperature values ​​corresponding to each moment in the S-shaped dynamic curve of the virtual leader agent are summarized into the S-shaped target trajectory data sequence of the virtual leader agent. The feedforward compensation coefficients after tuning of each independent control temperature zone agent and the consistency feedback gain after tuning of each independent control temperature zone agent are summarized together with the S-shaped target trajectory data sequence of the virtual leader agent into cooperative control parameters.

[0042] S4: Based on the cooperative control parameters, perform consistent cooperative adjustment based on the response phase, so that the response phase of each independent control temperature zone synchronously approaches the S-shaped target trajectory, and obtain the cooperative control correction amount.

[0043] In step S4, based on the collaborative control parameters, each independent temperature zone agent reads its current measured temperature value and the S-shaped target trajectory of the virtual leader agent in each control cycle, and calculates the current heating progress percentage of each independent temperature zone agent from the initial temperature to the target temperature.

[0044] The expression for calculating the current percentage of temperature rise from the initial temperature to the target temperature for each independent temperature-controlled agent is as follows: ; in, For the first An independent temperature control agent at the control time The current percentage of warming progress, For the first An independent temperature control agent at the control time Read its own current measured temperature value. For the first The starting temperature of each independently controlled temperature zone intelligent agent. For the first The target temperature of an independently controlled temperature zone intelligent agent.

[0045] The current heating process percentage is mapped to a phase range of 0° to 180° to serve as the response phase state quantity for each independent temperature control agent.

[0046] Furthermore, the response phase state quantity of each independent temperature control zone agent is obtained by dividing the current heating process percentage by 100 and then multiplying by 180. The response phase state quantity is set to zero when the current heating process percentage of each independent temperature control zone agent is zero, and to 180 when the current heating process percentage of each independent temperature control zone agent is 100%. Based on the response phase state quantity of each independent temperature control agent, the response phase state quantity of each independent temperature control agent is compared with the response phase state quantity of the adjacent independent temperature control agents, so that the response phase state quantity of each independent temperature control agent synchronously approaches the S-shaped target trajectory of the virtual leader agent.

[0047] Furthermore, based on the response phase state quantity of each independent temperature control zone intelligent agent, the response phase state quantities of adjacent independent temperature control zone intelligent agents are obtained through an industrial Ethernet distributed communication network. The difference between the response phase state quantity of each independent temperature control zone intelligent agent and the response phase state quantity of each adjacent independent temperature control zone intelligent agent is compared. At the same time, the difference between the response phase state quantity of each independent temperature control zone intelligent agent and the response phase reference value corresponding to the current control cycle time in the S-shaped target trajectory of the virtual leader intelligent agent read from the cooperative control parameters is compared. Based on the results of the above two difference comparisons, the control output quantity of each independent temperature control zone intelligent agent is increased or decreased to continuously reduce the difference between the response phase state quantity of each independent temperature control zone intelligent agent and the response phase reference value corresponding to the current control cycle time in the S-shaped target trajectory of the virtual leader intelligent agent.

[0048] During the process of synchronizing the response phase state of each independent control temperature zone agent with the S-shaped target trajectory of the virtual leader agent, the control adjustment amount generated by each independent control temperature zone agent is summarized as the cooperative control correction amount.

[0049] Furthermore, the change in the control output of each independent temperature zone agent relative to the control output of the previous control cycle is recorded based on the difference between its own response phase state and the response phase reference value corresponding to the S-shaped target trajectory of the virtual leader agent in each control cycle. All changes in the control output recorded by each independent temperature zone agent in all control cycles are summarized into a cooperative control correction quantity.

[0050] S5: Based on the collaborative control correction amount and combined with the initial state information of the material, perform time-series feedforward compensation based on thermal front propagation to obtain comprehensive control commands.

[0051] In step S5, the initial temperature value of the material is obtained by a material initial temperature detection device deployed at the inlet of the hot air tunnel furnace, based on the collaborative control correction amount.

[0052] Furthermore, the initial material temperature detection device deployed at the entrance of the hot air tunnel furnace starts the temperature measurement operation. The initial material temperature detection device performs non-contact measurement of the surface temperature of the material about to enter the furnace chamber of the hot air tunnel furnace. The initial material temperature detection device converts the measured temperature value into an electrical signal output. The controller connected to the initial material temperature detection device receives the electrical signal and reads the temperature value from it, and uses the temperature value as the initial material temperature value.

[0053] Material category information is obtained by material category identification sensors deployed at the entrance of the hot air tunnel furnace, and the initial temperature value and material category information of the material are summarized into the initial state information of the material.

[0054] Furthermore, the identification operation is initiated by a material category identification sensor deployed at the entrance of the hot blast tunnel furnace. The material category identification sensor collects the appearance or identification features of the material about to enter the furnace chamber of the hot blast tunnel furnace. The material category identification sensor compares the collected feature signals with the category templates stored internally to determine the category of the current material. The category information of the current material is used as the material category information. The initial temperature value of the material and the material category information are summarized into the initial state information of the material.

[0055] Based on the initial state information of the material and the collaborative control correction amount, the heat compensation amount required for each independent control temperature zone is determined according to the initial temperature value of the material and the material category information, and used as the timing feedforward compensation amount. The collaborative control correction amount and the timing feedforward compensation amount are combined to obtain the comprehensive control command for each independent control temperature zone.

[0056] Furthermore, based on the initial state information of the material and the collaborative control correction amount, the temperature difference between the target temperature of each independent control temperature zone and the material's own temperature when it arrives at the independent control temperature zone is determined according to the initial temperature value of the material. Based on this temperature difference, the required heat compensation amount for each independent control temperature zone is determined. Based on the material category information, the correction factor of the heat compensation coefficient for each independent control temperature zone is determined. Based on this correction factor, the required heat compensation amount for each independent control temperature zone is adjusted. The adjusted required heat compensation amount for each independent control temperature zone is used as the timing feedforward compensation amount for each independent control temperature zone. The change in the control output of each independent control temperature zone in the collaborative control correction amount is added to the timing feedforward compensation amount for each independent control temperature zone to obtain the comprehensive control command for each independent control temperature zone.

[0057] S6: Adjust the heating element, circulating fan and damper actuator based on the integrated control command, collect temperature data, obtain feedback data, construct a two-dimensional temperature field through the feedback data, calculate the temperature field evaluation index, and obtain the temperature field evaluation result.

[0058] In step S6, based on the integrated control command, the heating power adjustment, circulating fan speed adjustment, and damper opening adjustment in the integrated control command are sent to the heating element, circulating fan, and damper actuator respectively through the industrial Ethernet distributed communication network.

[0059] Furthermore, based on the integrated control command, the heating power adjustment, circulating fan speed adjustment, and damper opening adjustment of each independent control temperature zone recorded in the integrated control command are grouped and packaged according to the controller address of each independent control temperature zone. The packaged data of each independent control temperature zone is sent to the controller of the corresponding independent control temperature zone through the industrial Ethernet distributed communication network. After receiving the packaged data, the controller of the corresponding independent control temperature zone parses the heating power adjustment, circulating fan speed adjustment, and damper opening adjustment from the packaged data. The controller of the corresponding independent control temperature zone sends the heating power adjustment to the power adjustment terminal of the heating element, sends the circulating fan speed adjustment to the inverter setpoint terminal of the circulating fan, and sends the damper opening adjustment to the opening control terminal of the damper actuator.

[0060] Based on the heating power adjustment amount, circulating fan speed adjustment amount, and damper opening adjustment amount issued to the heating element, circulating fan, and damper actuator, the heating element, circulating fan, and damper actuator respectively perform heating power adjustment action, circulating fan speed adjustment action, and damper opening adjustment action.

[0061] Furthermore, based on the heating power adjustment amount sent to the heating element, the power adjustment terminal of the heating element changes the conduction time ratio of the heating element according to the value of the heating power adjustment amount to perform the heating power adjustment action; based on the circulating fan speed adjustment amount sent to the circulating fan, the frequency converter setpoint terminal of the circulating fan changes the output frequency of the frequency converter according to the value of the circulating fan speed adjustment amount to perform the circulating fan speed adjustment action; based on the damper opening adjustment amount sent to the damper actuator, the opening control terminal of the damper actuator changes the rotation angle of the damper actuator according to the value of the damper opening adjustment amount to perform the damper opening adjustment action.

[0062] After performing actions such as adjusting heating power, regulating circulating fan speed, and adjusting damper opening, temperature data for each independent control temperature zone is collected through a temperature sensor array and used as feedback data.

[0063] Furthermore, after performing the heating power adjustment, circulating fan speed adjustment, and damper opening adjustment actions, each temperature measuring point in the temperature sensor array deployed within each independent control temperature zone initiates a temperature measurement operation. Each temperature measuring point converts the measured temperature value into an electrical signal and transmits it through a signal line to the analog input port of the controller of the corresponding independent control temperature zone. The controller of the corresponding independent control temperature zone reads the temperature value of each temperature measuring point from the analog input port and stores the temperature value of each temperature measuring point along with the installation position coordinates of each temperature measuring point. The temperature values ​​of all temperature measuring points in all independent control temperature zones and their corresponding installation position coordinates are summarized into feedback data.

[0064] Based on the temperature values ​​of each temperature measuring point in the temperature sensor array within each independent control temperature zone in the feedback data, the temperature values ​​of each temperature measuring point in the temperature sensor array within each independent control temperature zone are spatially interpolated according to the installation position coordinates of each temperature measuring point in the temperature sensor array within each independent control temperature zone to obtain a two-dimensional temperature field distribution map of the hot air tunnel furnace.

[0065] Furthermore, a planar coordinate system is established with the width of the hot air tunnel furnace as the horizontal axis and the length of the hot air tunnel furnace as the vertical axis. In this planar coordinate system, the coordinate positions of each temperature measuring point are marked according to the installation position coordinates of each temperature measuring point in the temperature sensor array within each independent control temperature zone. The temperature value of each temperature measuring point is assigned to its coordinate position to form discrete point temperature data. The blank positions in the planar coordinate system without temperature measuring points are calculated using the inverse distance weighted average method. Specifically, for any blank position, several temperature measuring points with assigned temperature values ​​are selected within a preset range around the blank position. The temperature values ​​of all temperature measuring points with assigned temperature values ​​are weighted and summed according to their respective weight coefficients, and the result of the weighted sum is used as the temperature value of the blank position. The temperature values ​​of all temperature measuring points and the temperature values ​​of all blank positions are arranged according to their respective positions in the planar coordinate system to form a two-dimensional temperature field distribution map of the hot air tunnel furnace.

[0066] Based on the two-dimensional temperature field distribution map of the hot air tunnel furnace, the temperature difference between each temperature measuring point in the temperature sensor array within each independent control temperature zone is taken as the lateral temperature difference within each independent control temperature zone, the temperature difference between each temperature measuring point at the adjacent boundary of adjacent independent control temperature zones is taken as the longitudinal temperature difference between adjacent independent control temperature zones, and the variance of the temperature values ​​at all locations in the two-dimensional temperature field distribution map of the hot air tunnel furnace is taken as the overall uniformity coefficient of the temperature field.

[0067] Furthermore, the difference between the maximum and minimum temperatures at all locations within each independent temperature control zone is taken as the lateral temperature difference within each independent temperature control zone. Temperature values ​​at all locations within preset ranges on both sides of the adjacent boundary of adjacent independent temperature control zones are extracted from the two-dimensional temperature field distribution map of the hot blast tunnel furnace. The difference between the maximum and minimum temperatures at all locations within preset ranges on both sides of the adjacent boundary of adjacent independent temperature control zones is taken as the longitudinal temperature difference between adjacent independent temperature control zones. Temperature values ​​at all locations are extracted from the two-dimensional temperature field distribution map of the hot blast tunnel furnace. The square of the difference between the temperature value at each location and the average value is taken. The sum of the squares of all locations and divided by the total number of locations is taken as the variance of the temperature values ​​at all locations in the two-dimensional temperature field distribution map of the hot blast tunnel furnace. This variance is used as the overall uniformity coefficient of the temperature field.

[0068] The lateral temperature difference within each independent control temperature zone, the longitudinal temperature difference between adjacent independent control temperature zones, and the overall uniformity coefficient of the temperature field are summarized as the temperature field evaluation results.

[0069] Furthermore, the transverse temperature difference within each independent control temperature zone is arranged into a transverse temperature difference sequence according to the numbering order of each independent control temperature zone, and the longitudinal temperature difference between adjacent independent control temperature zones is arranged into a longitudinal temperature difference sequence according to the arrangement order of adjacent independent control temperature zones along the length of the hot air tunnel furnace. The overall uniformity coefficient of the temperature field is used as a separate evaluation index, and the transverse temperature difference sequence, the longitudinal temperature difference sequence, and the overall uniformity coefficient of the temperature field are combined into a temperature field evaluation result dataset.

[0070] S7: Adjust the weights of consistency coordination and timing feedforward compensation based on the temperature field evaluation results, and correct the temperature zone characteristic data to obtain updated temperature zone characteristic data. Update the coordination control parameters based on the updated temperature zone characteristic data and perform cyclic control to form a closed-loop coordination control process for the multi-temperature zone temperature field of the hot blast tunnel furnace.

[0071] In step S7, the transverse temperature difference within each independent control temperature zone, the longitudinal temperature difference between adjacent independent control temperature zones, and the overall uniformity coefficient of the temperature field are evaluated based on the temperature field evaluation results.

[0072] Furthermore, based on the transverse temperature difference within each independent control temperature zone, the longitudinal temperature difference between adjacent independent control temperature zones, and the overall uniformity coefficient of the temperature field in the temperature field evaluation results, a first preset threshold is set for the transverse temperature difference within each independent control temperature zone, a second preset threshold is set for the longitudinal temperature difference between adjacent independent control temperature zones, and a third preset threshold is set for the overall uniformity coefficient of the temperature field. The transverse temperature difference within each independent control temperature zone in the temperature field evaluation results is compared with the first preset threshold, the longitudinal temperature difference between adjacent independent control temperature zones in the temperature field evaluation results is compared with the second preset threshold, and the overall uniformity coefficient of the temperature field in the temperature field evaluation results is compared with the third preset threshold.

[0073] The transverse temperature difference within each independent control temperature zone, the longitudinal temperature difference between adjacent independent control temperature zones, and the overall uniformity coefficient of the temperature field are compared with their respective preset thresholds. Based on the comparison results, the weights of consistency coordination adjustment and time-series feedforward compensation are adjusted.

[0074] Furthermore, based on the comparison results of the transverse temperature difference within each independent control temperature zone with the first preset threshold and the comparison results of the overall temperature field uniformity coefficient with the third preset threshold, when the comparison results indicate that the transverse temperature difference within each independent control temperature zone exceeds the first preset threshold or the overall temperature field uniformity coefficient exceeds the third preset threshold, the weight of consistency coordination adjustment is increased by one step value; when the comparison results indicate that the transverse temperature difference within each independent control temperature zone is lower than the first preset threshold and the overall temperature field uniformity coefficient is lower than the third preset threshold, the weight of consistency coordination adjustment is decreased by one step value. Based on the comparison results of the longitudinal temperature difference between adjacent independent control temperature zones with the second preset threshold and the comparison results of the overall temperature field uniformity coefficient with the third preset threshold, when the comparison results indicate that the longitudinal temperature difference between adjacent independent control temperature zones exceeds the second preset threshold or the overall temperature field uniformity coefficient exceeds the third preset threshold, the weight of time-series feedforward compensation is increased by one step value; when the comparison results indicate that the longitudinal temperature difference between adjacent independent control temperature zones is lower than the second preset threshold and the overall temperature field uniformity coefficient is lower than the third preset threshold, the weight of time-series feedforward compensation is decreased by one step value.

[0075] Based on the transverse temperature difference within each independent control temperature zone and the longitudinal temperature difference between adjacent independent control temperature zones in the temperature field evaluation results, the gain coefficient, time constant, and pure lag time in the temperature zone characteristic data of independent control temperature zones that exceed their respective preset thresholds are corrected.

[0076] Furthermore, based on the transverse temperature difference within each independent control temperature zone and the longitudinal temperature difference between adjacent independent control temperature zones in the temperature field evaluation results, the transverse temperature difference within each independent control temperature zone is compared with a first preset threshold, and the longitudinal temperature difference between adjacent independent control temperature zones is compared with a second preset threshold. When the comparison result indicates that the transverse temperature difference within an independent control temperature zone exceeds the first preset threshold, the independent control temperature zone is marked as a temperature zone to be corrected. When the comparison result indicates that the longitudinal temperature difference between a pair of adjacent independent control temperature zones exceeds the second preset threshold, the downstream independent control temperature zone in this pair of adjacent independent control temperature zones is marked as a temperature zone to be corrected. Correction operations are performed on all independent control temperature zones marked as temperature zones to be corrected. Specifically, the correction operations are as follows: the gain coefficient in the temperature zone characteristic data of the independent control temperature zone is increased by one correction step value; the time constant in the temperature zone characteristic data of the independent control temperature zone is decreased by one correction step value; and the pure lag time in the temperature zone characteristic data of the independent control temperature zone is decreased by one correction step value.

[0077] In control theory, the time constant is defined as the ratio of system heat capacity to thermal conductivity. When a tunnel furnace is in an unloaded state and a fully loaded state, the total heat capacity inside the furnace undergoes a substantial change. The material itself constitutes part of the furnace's heat capacity, and the material moves continuously along the conveying direction within the furnace. This moving heat capacity causes the equivalent heat capacity of each temperature zone to change over time. The time constant identified based on the initial unloaded state can no longer accurately describe the thermal inertia characteristics under full-load conditions. Therefore, it is necessary to correct the identified parameters based on the temperature field uniformity evaluation results so that the model parameters approximate the equivalent values ​​under the current operating conditions.

[0078] The gain coefficient reflects the proportional relationship between the steady-state temperature change and the input power change. This proportional relationship depends not only on the heater power and furnace heat capacity, but also on the combined influence of the convective and radiative heat transfer coefficients inside the furnace. When the operating temperature range of the tunnel furnace changes, the radiative heat transfer coefficient changes with the fourth power of the temperature, and the convective heat transfer coefficient changes with the hot air velocity and temperature, causing a shift in the equivalent gain coefficient.

[0079] The gain coefficient, time constant, and pure time delay in the corrected individual control temperature zone characteristic data, as well as the gain coefficient, time constant, and pure time delay in the uncorrected individual control temperature zone characteristic data, are combined to form the updated temperature zone characteristic data.

[0080] Furthermore, the gain coefficient, time constant, and pure time delay in the characteristic data of each independent control temperature zone after the correction operation are taken as the gain coefficient, time constant, and pure time delay in the characteristic data of each independent control temperature zone after the correction operation. The gain coefficient, time constant, and pure time delay in the characteristic data of each independent control temperature zone that is not marked as a temperature zone to be corrected are taken as the gain coefficient, time constant, and pure time delay in the characteristic data of each independent control temperature zone after the correction operation. The gain coefficient, time constant, and pure time delay in the characteristic data of each independent control temperature zone and the gain coefficient, time constant, and pure time delay in the characteristic data of each independent control temperature zone after the correction operation are taken as the gain coefficient, time constant, and pure time delay in the characteristic data of each independent control temperature zone after the correction operation are taken as the gain coefficient, time constant, and pure time delay in the characteristic data of each independent control temperature zone after the correction operation are taken as the updated temperature zone characteristic data.

[0081] Based on the gain coefficient, time constant, and pure time delay of each independent control temperature zone in the updated temperature zone characteristic data, the feedforward compensation coefficient and consistency feedback gain of each independent control temperature zone agent are readjusted to obtain the updated cooperative control parameters.

[0082] Furthermore, based on the gain coefficient, time constant, and pure time delay of each independent control temperature zone in the updated temperature zone characteristic data, the gain coefficient and pure time delay of each independent control temperature zone in the updated temperature zone characteristic data are substituted into the retuning rule of the feedforward compensation coefficient to determine the updated feedforward compensation coefficient of each independent control temperature zone agent. The gain coefficient and pure time delay of each independent control temperature zone in the updated temperature zone characteristic data are substituted into the retuning rule of the consistency feedback gain to determine the updated consistency feedback gain of each independent control temperature zone agent. The retuning rule of the feedforward compensation coefficient is that the updated feedforward compensation coefficient is inversely proportional to the gain coefficient in the updated temperature zone characteristic data and directly proportional to the pure time delay in the updated temperature zone characteristic data. The retuning rule of the consistency feedback gain is that the updated consistency feedback gain is inversely proportional to the gain coefficient in the updated temperature zone characteristic data and inversely proportional to the pure time delay in the updated temperature zone characteristic data. The updated feedforward compensation coefficient and the updated consistency feedback gain of each independent control temperature zone agent are summarized into the updated cooperative control parameters.

[0083] The retuning formula for the feedforward compensation coefficient is as follows: ; in, For the first The update feedforward compensation coefficients of each independent temperature zone control agent. For the first The feedforward compensation coefficients of each independent temperature control agent before this readjustment. For the first The gain coefficient of each independent control temperature zone in updating the temperature zone characteristic data. For the first The gain coefficient of each independent control temperature zone in the temperature zone characteristic data before this readjustment. For the first The pure lag time of each independent control temperature zone in updating temperature zone characteristic data. For the first The pure lag time of each independent control temperature zone in the temperature zone characteristic data before this readjustment. This is the step size factor for correcting the gain bias against the feedforward compensation coefficients. This is the step size factor for correcting the feedforward compensation coefficient based on the pure time lag deviation. The retuning formula for the consistency feedback gain is as follows: ; in, For the first Update consistency feedback gain for each independent temperature zone control agent For the first Consistent feedback gain of each independent temperature zone control agent before this readjustment. For the first The gain coefficient of each independent control temperature zone in updating the temperature zone characteristic data. For the first The gain coefficient of each independent control temperature zone in the temperature zone characteristic data before this readjustment. For the first The pure lag time of each independent control temperature zone in updating temperature zone characteristic data. For the first The pure lag time of each independent control temperature zone in the temperature zone characteristic data before this readjustment. This is the step size factor for correcting the gain deviation on the consistency feedback gain. This is the step size factor for correcting the uniformity feedback gain based on the pure time lag deviation.

[0084] Based on the updated collaborative control parameters, the operation of consistent collaborative adjustment based on the response phase is returned to perform based on the collaborative control parameters, forming a closed-loop collaborative control process for the temperature field of the multi-temperature zone of the hot blast tunnel furnace.

[0085] Furthermore, based on the updated collaborative control parameters, the updated feedforward compensation coefficient and updated consistency feedback gain of each independent control temperature zone agent in the updated collaborative control parameters are replaced with the corresponding feedforward compensation coefficient and consistency feedback gain in the original collaborative control parameters. The updated collaborative control parameters are used as the new collaborative control parameters to return to the execution of the consistency collaborative adjustment operation based on the response phase. After each return execution, the subsequent steps are executed sequentially until the updated temperature zone characteristic data is obtained again. After each time the updated temperature zone characteristic data is obtained, the operation of updating the collaborative control parameters based on the updated temperature zone characteristic data is repeated to form a closed-loop collaborative control process for the multi-temperature zone temperature field of the hot blast tunnel furnace.

[0086] Example 2

[0087] like Figure 1 As shown, this embodiment provides a distributed collaborative control method for the temperature field of multiple temperature zones in a hot blast tunnel furnace, including: To verify the effectiveness of the distributed collaborative control method for the multi-temperature zone temperature field of a hot blast tunnel furnace provided by this invention, a certain model of hot blast tunnel furnace was used as the test object. This hot blast tunnel furnace was divided into four independent control temperature zones along the material travel direction, and the following comparative test experiment was conducted. Using the traditional normalized deviation correction scheme, taking the first independent control temperature zone as an example, under the condition that the measured temperature value of the first independent control temperature zone is 160℃ and the target temperature is 200℃, the normalized temperature value calculation formula used in the traditional scheme is as follows: ; in For the first Normalized temperature values ​​for each independently controlled temperature zone For the first Measured temperature values ​​for each independently controlled temperature zone. For the first The target temperature value for each independently controlled temperature zone. The normalized temperature value calculated using this formula is 0.80. This normalized temperature value only reflects the degree of deviation of the current temperature and cannot determine whether the temperature zone is in the initial stage of heating or close to steady state. The correction gain calculated based on this uses the same gain allocation logic in the initial heating stage and the deceleration stage, resulting in a mismatch between the control action and the actual heating process of the temperature zone.

[0088] This invention employs a consistent collaborative regulation based on the response phase, and the phase angle calculation formula is as follows: ; in For the first An independent temperature control agent at the control time The response phase state quantity, For the first An independent temperature control agent at the control time Read its own current measured temperature value. For the first The starting temperature of each independently controlled temperature zone intelligent agent. For the first The target temperature of an agent in an independently controlled temperature zone. The initial temperature of the first independently controlled temperature zone is 80℃, the measured temperature is 160℃, and the target temperature is 200℃. Substituting these values ​​into the phase angle calculation formula, the response phase state variable is obtained as follows: ; The response phase state variable is in the high phase range of 90° to 180°, indicating that the first independent control temperature zone has entered the deceleration and heating phase. At this time, the control law actively applies reverse cooperative correction to prevent overshoot. Simultaneously, the measured temperature values ​​of the adjacent second independent control temperature zone are obtained. The initial temperature of the second independent control temperature zone is 75℃, the current measured temperature is 155℃, and the target temperature is 200℃. Substituting these values ​​into the phase angle calculation formula, the response phase state variable of the second independent control temperature zone is obtained as follows: ; The difference in response phase state between the first independent temperature control zone and the second independent temperature control zone is: The phase difference is less than the preset phase difference threshold of 15°, indicating that the heating process of the first independent control temperature zone and the second independent control temperature zone are synchronized. The consistent and coordinated adjustment effectively avoids the process mismatch problem between adjacent temperature zones.

[0089] In the time-series feedforward compensation verification, the initial material temperature was 35℃, obtained by a material initial temperature detection device deployed at the inlet of the hot air tunnel furnace. The material category identification sensor identified the current material category as Category A. The heat required for each unit mass of material in Category A to increase by 1℃ is 2.2 kJ / (kg・℃). The material temperature rise requirement set for the third independent control temperature zone is that the material needs to rise from its current temperature to 165℃ when entering the third independent control temperature zone, with a material mass flow rate of 0.8 kg / s. The formula for calculating the heat compensation required for time-series feedforward compensation is: ; in For the first The amount of heat compensation required for each independently controlled temperature zone For material mass flow rate, The specific heat capacity of the material. For the first The target temperature value for each independently controlled temperature zone. For materials to enter the first The temperature values ​​in the first two independently controlled temperature zones. The target temperature value for the third independently controlled temperature zone is 165℃. When the material enters the third independently controlled temperature zone, its temperature rises to 115℃ after being heated in the first two temperature zones. Substituting this into the heat compensation calculation formula, we get: ; The heat compensation amount is injected into the timing feedforward compensation amount before the material reaches the third independent control temperature zone, and the third independent control temperature zone adjusts the heating power in advance based on this heat compensation amount. Traditional solutions lack a forward-looking adjustment mechanism based on thermal front propagation, and only begin to respond after the material reaches the third independent control temperature zone, resulting in a lag in the actual output of the heat compensation amount compared to the solution of this invention.

[0090] In a comparative experiment on the uniformity of the steady-state temperature field, both the proposed method and the traditional normalized deviation correction method were run continuously for 120 minutes. The formula for calculating the overall uniformity coefficient of the temperature field is as follows: ; in, The coefficient representing the overall uniformity of the temperature field. This represents the total number of locations on the two-dimensional temperature field distribution map of the hot blast tunnel furnace. For the first Temperature values ​​at each location point This is the average temperature value at all locations. The overall temperature field uniformity coefficient using the scheme of this invention is... The overall uniformity coefficient of the temperature field using the traditional normalized deviation correction scheme is: The comparison results are as follows: % The overall temperature field uniformity coefficient of the present invention is reduced by 72.2% compared to the traditional method. The average value of the lateral temperature difference within each independently controlled temperature zone is obtained using the present invention. The traditional solution is adopted. The average longitudinal temperature difference between adjacent independent controlled temperature zones is calculated using the method described in this invention. The traditional solution is adopted. The above comparative data shows that the distributed collaborative control method for the multi-temperature zone temperature field of the hot blast tunnel furnace provided by this invention achieves better synchronization of the heating process and overall temperature field performance. In terms of uniformity, both solutions have achieved a quality improvement superior to traditional solutions.

[0091] It should be understood that the present invention is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.

Claims

1. A distributed collaborative control method for the temperature field of a multi-temperature zone in a hot blast tunnel furnace, characterized in that, The specific steps include the following: The hot air tunnel furnace is divided into multiple independent temperature control zones and an industrial Ethernet distributed communication network is established to obtain physical parameter data. Based on physical parameter data, step response identification is performed on each independent control temperature zone to obtain dynamic parameters and cross-coupling parameters, and temperature zone characteristic data is obtained. Based on temperature zone characteristic data, a virtual leader intelligent agent is set up to generate an S-shaped target trajectory and adjust the collaborative control parameters. Based on the coordinated control parameters, consistent coordinated adjustment based on response phase is performed so that the response phase of each independent control temperature zone synchronously approaches the S-shaped target trajectory, thus obtaining the coordinated control correction amount; Based on the collaborative control correction amount and combined with the initial state information of the material, a time-series feedforward compensation based on the propagation of the thermal front is performed to obtain a comprehensive control command; The heating element, circulating fan and damper actuator are adjusted based on the integrated control command, and temperature data is collected to obtain feedback data. A two-dimensional temperature field is constructed based on the feedback data and the temperature field evaluation index is calculated to obtain the temperature field evaluation result. Based on the temperature field evaluation results, the weights of consistency coordination and timing feedforward compensation are adjusted, and the temperature zone characteristic data is corrected to obtain updated temperature zone characteristic data. The coordination control parameters are updated according to the updated temperature zone characteristic data for cyclic control, forming a closed-loop coordination control process for the multi-temperature zone temperature field of the hot blast tunnel furnace.

2. The distributed collaborative control method for the temperature field of a multi-temperature zone in a hot blast tunnel furnace according to claim 1, characterized in that, The process of dividing the hot blast tunnel furnace into multiple independent temperature control zones and establishing an industrial Ethernet distributed communication network yields physical parameter data including: The furnace chamber of the hot air tunnel furnace is divided into N independent temperature control zones along the material travel direction. Each independent temperature control zone is equipped with a heating element, a circulating fan, a damper actuator, a temperature sensor array and a controller. Heat insulation partitions are installed between each adjacent independent temperature control zone. A material initial temperature detection device and a material category identification sensor are deployed at the entrance of the hot air tunnel furnace. Based on the division and configuration of each independent control temperature zone of the hot air tunnel furnace, the controllers of each independent control temperature zone are connected to the same industrial Ethernet to establish an industrial Ethernet distributed communication network. Based on the industrial Ethernet distributed communication network, the parameters of each mechanism configured in each independent control temperature zone are summarized to obtain physical parameter data.

3. The distributed collaborative control method for the temperature field of a multi-temperature zone in a hot blast tunnel furnace according to claim 1, characterized in that, The step response identification of each independent control temperature zone based on physical parameter data, obtaining dynamic parameters and cross-coupling parameters, and obtaining temperature zone characteristic data include: After the hot air tunnel furnace is run to a stable initial operating condition, a step increment is applied to the heating power of each independent control temperature zone, and the temperature response data of each temperature measuring point in the temperature sensor array inside each independent control temperature zone is recorded simultaneously until each independent control temperature zone re-enters a steady state, and the step response curve of each independent control temperature zone is obtained. Calculate the gain coefficient, time constant, and pure time delay of each independent control temperature zone based on the step response curve of each independent control temperature zone. During the process of applying a step increment to the heating power of each independent control temperature zone, the temperature fluctuation data of the independent control temperature zone adjacent to the independent control temperature zone are recorded simultaneously, and the cross-coupling gain coefficient between the adjacent independent control temperature zones is calculated based on the recorded temperature fluctuation data of the adjacent independent control temperature zones. The gain coefficient, time constant, and pure time delay of each independent control temperature zone, as well as the cross-coupling gain coefficient between adjacent independent control temperature zones, are summarized into temperature zone characteristic data.

4. The distributed collaborative control method for the temperature field of a multi-temperature zone in a hot blast tunnel furnace according to claim 1, characterized in that, The step of setting up a virtual leader agent based on temperature zone characteristic data, generating an S-shaped target trajectory, and tuning cooperative control parameters includes: Based on the gain coefficient and pure lag time of each independent control temperature zone in the temperature zone characteristic data, an S-shaped dynamic curve of a virtual leader agent is set as the ideal temperature trajectory of the virtual leader agent according to the baking or drying process requirements. Based on the S-shaped dynamic curve of the virtual leader agent and the gain coefficient and pure lag time of each independent control temperature zone in the temperature zone characteristic data, the feedforward compensation coefficient and consistency feedback gain of each independent control temperature zone agent are tuned. The S-shaped dynamic curve of the virtual leader agent and the feedforward compensation coefficient and consistency feedback gain after tuning of each independent control temperature zone agent are summarized into cooperative control parameters.

5. The distributed collaborative control method for the temperature field of a multi-temperature zone in a hot blast tunnel furnace according to claim 1, characterized in that, The consistent coordinated adjustment based on response phase, performed according to the coordinated control parameters, synchronizes the response phases of each independent control temperature zone towards the S-shaped target trajectory, resulting in the following coordinated control correction amounts: Based on the collaborative control parameters, each independent temperature zone agent reads its current measured temperature value and the S-shaped target trajectory of the virtual leader agent in each control cycle, and calculates the current heating progress percentage of each independent temperature zone agent from the initial temperature to the target temperature. The current heating process percentage is mapped to a phase range of 0° to 180° to serve as the response phase state quantity for each independent temperature control agent; Based on the response phase state quantity of each independent temperature control agent, the response phase state quantity of each independent temperature control agent is compared with the response phase state quantity of the adjacent independent temperature control agents, so that the response phase state quantity of each independent temperature control agent synchronously approaches the S-shaped target trajectory of the virtual leader agent. During the process of synchronizing the response phase state of each independent control temperature zone agent with the S-shaped target trajectory of the virtual leader agent, the control adjustment amount generated by each independent control temperature zone agent is summarized as the cooperative control correction amount.

6. The distributed collaborative control method for the temperature field of a multi-temperature zone in a hot blast tunnel furnace according to claim 1, characterized in that, The comprehensive control commands obtained by performing time-series feedforward compensation based on thermal front propagation, combined with the initial state information of the material and the collaborative control correction amount, include: Based on the collaborative control correction amount, the initial material temperature value is obtained through the material initial temperature detection device deployed at the inlet of the hot air tunnel furnace; Material category information is obtained by material category identification sensors deployed at the entrance of the hot air tunnel furnace, and the initial temperature value and material category information of the material are summarized into the initial state information of the material. Based on the initial state information of the material and the collaborative control correction amount, the heat compensation amount required for each independent control temperature zone is determined according to the initial temperature value of the material and the material category information, and used as the timing feedforward compensation amount. The collaborative control correction amount and the timing feedforward compensation amount are combined to obtain the comprehensive control command for each independent control temperature zone.

7. The distributed collaborative control method for the temperature field of a multi-temperature zone in a hot blast tunnel furnace according to claim 1, characterized in that, The process involves adjusting the heating element, circulating fan, and damper actuator based on integrated control commands, and collecting temperature data to obtain feedback data, including: Based on the integrated control command, the heating power adjustment, circulating fan speed adjustment, and damper opening adjustment in the integrated control command are sent to the heating element, circulating fan, and damper actuator respectively through the industrial Ethernet distributed communication network; Based on the heating power adjustment amount, circulating fan speed adjustment amount, and damper opening adjustment amount issued to the heating element, circulating fan, and damper actuator, the heating element, circulating fan, and damper actuator respectively perform heating power adjustment action, circulating fan speed adjustment action, and damper opening adjustment action; After performing actions such as adjusting heating power, regulating circulating fan speed, and adjusting damper opening, temperature data for each independent control temperature zone is collected through a temperature sensor array and used as feedback data.

8. The distributed collaborative control method for the temperature field of a multi-temperature zone in a hot blast tunnel furnace according to claim 1, characterized in that, The process of constructing a two-dimensional temperature field using feedback data and calculating temperature field evaluation indices to obtain temperature field evaluation results includes: Based on the temperature values ​​of each temperature measuring point in the temperature sensor array within each independent control temperature zone in the feedback data, the temperature values ​​of each temperature measuring point in the temperature sensor array within each independent control temperature zone are spatially interpolated according to the installation position coordinates of each temperature measuring point in the temperature sensor array within each independent control temperature zone to obtain a two-dimensional temperature field distribution map of the hot air tunnel furnace. Based on the two-dimensional temperature field distribution map of the hot air tunnel furnace, the temperature difference between each temperature measuring point in the temperature sensor array within each independent control temperature zone is taken as the transverse temperature difference within each independent control temperature zone, the temperature difference between each temperature measuring point at the adjacent boundary of adjacent independent control temperature zones is taken as the longitudinal temperature difference between adjacent independent control temperature zones, and the variance of the temperature values ​​at all locations in the two-dimensional temperature field distribution map of the hot air tunnel furnace is taken as the overall uniformity coefficient of the temperature field. The lateral temperature difference within each independent control temperature zone, the longitudinal temperature difference between adjacent independent control temperature zones, and the overall uniformity coefficient of the temperature field are summarized as the temperature field evaluation results.

9. The distributed collaborative control method for the temperature field of a multi-temperature zone in a hot blast tunnel furnace according to claim 1, characterized in that, The process of adjusting the weights of consistency coordination and time-series feedforward compensation based on temperature field evaluation results, and correcting the temperature region characteristic data to obtain updated temperature region characteristic data includes: Based on the transverse temperature difference within each independent control temperature zone, the longitudinal temperature difference between adjacent independent control temperature zones, and the overall uniformity coefficient of the temperature field in the temperature field evaluation results; The transverse temperature difference within each independent control temperature zone, the longitudinal temperature difference between adjacent independent control temperature zones, and the overall uniformity coefficient of the temperature field are compared with their respective preset thresholds. Based on the comparison results, the weights of consistency coordination adjustment and timing feedforward compensation are adjusted. Based on the transverse temperature difference within each independent control temperature zone and the longitudinal temperature difference between adjacent independent control temperature zones in the temperature field evaluation results, the gain coefficient, time constant, and pure lag time in the temperature zone characteristic data of the independent control temperature zones whose transverse temperature difference within each independent control temperature zone and the longitudinal temperature difference between adjacent independent control temperature zones exceed their respective preset thresholds are corrected. The gain coefficient, time constant, and pure time delay in the corrected individual control temperature zone characteristic data, as well as the gain coefficient, time constant, and pure time delay in the uncorrected individual control temperature zone characteristic data, are combined to form the updated temperature zone characteristic data.

10. The distributed collaborative control method for the temperature field of a multi-temperature zone in a hot blast tunnel furnace according to claim 1, characterized in that, The process of updating collaborative control parameters based on updated temperature zone characteristic data to form a closed-loop collaborative control flow for the multi-temperature zone temperature field of the hot blast tunnel furnace includes: Based on the gain coefficient, time constant, and pure time delay of each independent control temperature zone in the updated temperature zone characteristic data, the feedforward compensation coefficient and consistency feedback gain of each independent control temperature zone agent are readjusted to obtain the updated cooperative control parameters. Based on the updated collaborative control parameters, the operation of consistent collaborative adjustment based on the response phase is returned to perform based on the collaborative control parameters, forming a closed-loop collaborative control process for the temperature field of the multi-temperature zone of the hot blast tunnel furnace.

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