Magnetic material sintering control method and system based on multi-temperature-zone monitoring
By using multi-temperature zone monitoring and adaptive decoupling gain correction, thermal coupling interference during the sintering process of magnetic materials is compensated in real time, solving the problem of distortion in the high-temperature range of the traditional static decoupling model and achieving consistency and production stability of magnetic material products.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SHANXI DONGMU MAGNETOELECTRIC CO LTD
- Filing Date
- 2026-04-10
- Publication Date
- 2026-05-12
Smart Images
Figure CN122015518A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of industrial control technology, and in particular to a method and system for controlling the sintering of magnetic materials based on multi-temperature zone monitoring. Background Technology
[0002] Magnetic materials, especially high-performance neodymium iron boron permanent magnets and ferrite magnets, are key fundamental materials in modern industry. Their magnetic properties and microstructure are highly dependent on the precision of temperature control during the sintering process. In industrial production, to meet the demands of large-scale continuous production, continuous tunnel kilns or pusher furnaces are typically used. These devices divide the furnace chamber into multiple continuous temperature zones, such as a debinding zone, a preheating zone, a high-temperature sintering zone, and a cooling zone. Each zone requires strict temperature control according to a specific process curve.
[0003] In actual operation, because adjacent temperature zones are physically connected and lack ideal thermal insulation, severe thermal coupling interference occurs. That is, power regulation in one temperature zone can significantly change the temperature of adjacent temperature zones through heat conduction, convection, and radiation. Currently, a feedforward decoupling control method based on a static model is commonly used. This method calculates a fixed decoupling matrix for compensation by pre-testing the transfer function under steady-state conditions.
[0004] However, in the traditional method based on the principle of linear superposition, as the furnace temperature rises during the sintering of magnetic materials, thermal radiation becomes the dominant heat transfer mechanism. According to the Stefan-Boltzmann law, radiative heat flux is proportional to the fourth power of temperature. This high nonlinearity causes the linear decoupling model calibrated based on a single operating condition to be severely distorted at high temperatures. At the same time, with long-term operation of the equipment, aging of heating elements, decline in the thermal insulation performance of the furnace lining, and fluctuations in the load will all cause the actual thermal coupling coefficient to drift. The fixed static model cannot detect these changes, resulting in compensation signals that are too strong or too weak, thus affecting the consistency of magnetic material products. Summary of the Invention
[0005] To address the problem that traditional static decoupling models cannot adapt to high-temperature nonlinearity and time-varying parameter drift, resulting in poor temperature control accuracy and affecting the consistency of magnetic material products, this invention provides a magnetic material sintering control method and system based on multi-temperature zone monitoring.
[0006] In a first aspect, the present invention provides a method for controlling the sintering of magnetic materials based on multi-temperature zone monitoring, which adopts the following technical solution: A magnetic material sintering control method based on multi-temperature zone monitoring includes: real-time acquisition of the power and temperature of the main control temperature zone, and the temperatures of all disturbed temperature zones within the main control temperature zone; determining the dynamic thermal coupling response residual for each disturbed temperature zone, representing the deviation between the actual temperature change rate of the disturbed temperature zone and the theoretical prediction value under the current operating condition, based on the temperature magnitude of the main control temperature zone; determining the time-varying characteristics of heat transfer from the main control temperature zone to each disturbed temperature zone, representing the drift of the physical characteristics of the thermal coupling channel, based on the dynamic thermal coupling response residual; determining the adaptive decoupling gain correction factor from the main control temperature zone to each disturbed temperature zone based on the time-varying characteristics of heat transfer and a set sensitivity adjustment coefficient; calculating the feedforward decoupling output signal for each disturbed temperature zone using the adaptive decoupling gain correction factor, a preset static coupling gain of the main control temperature zone to the controlled temperature zone, and the power change of the main control temperature zone; and superimposing the feedforward decoupling output signal into the control loop of the disturbed temperature zone to achieve dynamic compensation for thermal coupling interference and complete the magnetic material sintering control based on multi-temperature zone monitoring.
[0007] The beneficial effects are as follows: By collecting multi-dimensional data from the main control temperature zone and the disturbed temperature zone in real time, an evaluation model for the dynamic thermal coupling response residual was constructed, which accurately reflects the deviation between the actual temperature change rate and the theoretical prediction value, providing a reliable data foundation for the identification of time-varying characteristics of heat transfer; by calculating the time-varying characteristics of heat transfer, dynamic perception of the drift of physical characteristics of the thermal coupling channel was realized, effectively capturing the influence of factors such as heating element aging and furnace lining insulation performance degradation on thermal coupling; by calculating the adaptive decoupling gain correction factor, dynamic compensation for static coupling gain was realized, and the decoupling strength was adjusted according to real-time operating conditions, improving the decoupling control accuracy under high-temperature nonlinear conditions; based on the dynamic compensation of the feedforward decoupling output signal, thermal coupling interference in multiple temperature zones was effectively suppressed, improving the temperature control accuracy and product consistency of the magnetic material sintering process.
[0008] Furthermore, the dynamic thermal coupling response residual satisfies: In the formula, Disturbed temperature zone exist The dynamic thermal coupling response residual at time t, Main temperature control zone exist Temperature at any moment The set high temperature threshold, Disturbed temperature zone exist The rate of temperature change at any given time Main temperature control zone To the disturbed temperature zone Thermal response time constant, Main temperature control zone To the disturbed temperature zone The heat transfer delay time, For the set main control temperature zone For controlled temperature zone Static coupling gain, Main temperature control zone exist Power at any moment It is a natural constant. and Main temperature control zone With the disturbed temperature zone exist Temperature at any moment for The ambient temperature at any given time It is the Stefan constant. The main temperature control zone obtained based on the radiative heat transfer formula With the disturbed temperature zone The radiative heat exchange coefficient.
[0009] The beneficial effects are as follows: by constructing a piecewise function model, the accurate calculation of the dynamic thermal coupling response residuals in different temperature ranges is realized. The low temperature range uses an exponential decay model to reflect the conduction and convection characteristics, while the high temperature range uses a fourth-power radiation model to accurately describe nonlinear radiation heat transfer. This enables accurate evaluation of the real-time state changes of the thermal coupling channel and provides a reliable residual basis for time-varying feature identification.
[0010] Furthermore, the thermal response time constant and the heat transfer delay time are obtained as follows: During the system initialization phase, a power step is applied to the main control temperature zone, and the temperature response curve of the disturbed temperature zone is measured. After the disturbed temperature zone begins to respond, the dynamic rate parameter of the temperature transitioning from the initial state to the new steady state is obtained by fitting the temperature response curve of the step test with a first-order inertial element. The lag time at which the temperature response of the disturbed temperature zone begins to respond after the power change in the main control temperature zone is transmitted to the disturbed temperature zone is used as the heat transfer delay time. The difference between the moment when the power is applied and the moment when the temperature of the disturbed temperature zone first changes significantly during the step test is used as the heat transfer delay time.
[0011] Furthermore, the time-varying characteristics of heat transfer satisfy: In the formula, Main temperature control zone To the disturbed temperature zone exist Time-varying characteristics of heat transfer at any given moment Disturbed temperature zone exist The dynamic thermal coupling response residual at time t, Disturbed temperature zone The equivalent heat capacity of the furnace body is used to characterize the heat storage capacity of the furnace body. is the Stefan constant in thermodynamics. The main temperature control zone obtained based on the radiative heat transfer formula With the disturbed temperature zone The radiative heat exchange coefficient, and Main temperature control zone With the disturbed temperature zone exist Temperature at any moment This is a hyperparameter used to prevent the denominator from being zero.
[0012] The beneficial effects are as follows: by constructing a fractional function that includes the dynamic thermal coupling response residual and the radiation heat exchange term, a scientific evaluation of the time-varying characteristics of heat transfer is realized, which accurately reflects the relative deviation between actual thermal coupling and theoretical radiation heat transfer, effectively captures the influence of factors such as heating element aging and furnace lining insulation performance on heat transfer characteristics, and provides a reliable physical characteristic evaluation basis for adaptive decoupling gain correction.
[0013] Furthermore, the adaptive decoupling gain correction factor satisfies: In the formula, Main temperature control zone For the disturbed temperature region exist The adaptive decoupling gain correction factor at time step. for The set sensitivity adjustment coefficient, The length of the sliding window. As an index to historical moments, Main temperature control zone To the disturbed temperature zone exist Time-varying characteristics of heat transfer at any given moment It is a natural constant.
[0014] The beneficial effects are as follows: by constructing a linear correction model that includes a weighted average of historical time-varying features, a comprehensive evaluation of the adaptive decoupling gain correction factor is achieved. The exponential weighted average ensures a higher weight for recent time-varying features, and the sliding window mechanism balances response speed and stability. Thus, the decoupling strength can be adjusted according to the real-time drift state of the thermally coupled channel, thereby improving the decoupling control accuracy under high-temperature nonlinear conditions.
[0015] Furthermore, the determination of the adaptive decoupling gain correction factor from the main control temperature zone to each disturbed temperature zone also includes noise suppression processing: when the absolute value of the time-varying heat transfer characteristic is less than a preset noise threshold, the adaptive decoupling gain correction factor of the previous moment remains unchanged.
[0016] Furthermore, the feedforward decoupling output signal satisfies: In the formula, From the main temperature control zone For the disturbed temperature region exist The feedforward decoupling output signal at time 1. Main temperature control zone For the disturbed temperature region exist The adaptive decoupling gain correction factor at time step. For the set main control temperature zone For controlled temperature zone Static coupling gain, Main temperature control zone exist The change in power between time 1 and the previous time. Disturbed temperature zone The influence coefficient of its own temperature change on the relationship with power.
[0017] The beneficial effects are as follows: by constructing a product term that includes an adaptive correction factor and a power change, a scientific evaluation of the feedforward decoupling output signal is achieved, ensuring that the amplitude of the decoupling signal can be dynamically adjusted according to the real-time state of the thermal coupling channel. When the heat transfer characteristics drift, the correction factor automatically adjusts the decoupling strength, effectively improving the adaptability and stability of multi-temperature zone decoupling control.
[0018] Furthermore, when multiple main control temperature zones simultaneously generate thermal coupling interference to the same disturbed temperature zone, the algebraic sum of the feedforward decoupling output signals from each main control temperature zone to the disturbed temperature zone is used as the final feedforward decoupling output signal of the disturbed temperature zone.
[0019] Furthermore, the static coupling gain is obtained as follows: during the system initialization phase, a power step is applied to the main control temperature zone, and the temperature response curve of the disturbed temperature zone is measured; the ratio of the steady-state temperature rise of the temperature response curve to the power step is taken as the static coupling gain of the main control temperature zone to the controlled temperature zone.
[0020] Secondly, the present invention provides a magnetic material sintering control system based on multi-temperature zone monitoring, which adopts the following technical solution: A magnetic material sintering control system based on multi-temperature zone monitoring includes a processor and a memory. The memory stores computer program instructions, which, when executed by the processor, implement the aforementioned magnetic material sintering control method based on multi-temperature zone monitoring.
[0021] By adopting the above technical solution, a computer program is generated from the above-mentioned magnetic material sintering control method based on multi-temperature zone monitoring, and stored in the memory so that it can be loaded and executed by the processor. In this way, a terminal device can be made based on the memory and the processor for convenient use.
[0022] The present invention has the following technical effects: (1) In view of the problem that traditional static decoupling models cannot cope with the nonlinearity of radiation heat transfer in high-temperature section and the drift of thermal coupling coefficient caused by equipment aging, furnace lining performance degradation and load fluctuation, this invention collects power and temperature data of the main control temperature zone and the disturbed temperature zone in real time, calculates the thermal coupling response residual based on the temperature of the main control temperature zone, accurately captures the physical characteristic drift of the thermal coupling channel, and generates an adaptive decoupling gain correction factor in combination with the sensitivity adjustment coefficient, thereby adjusting the feedforward decoupling output signal in real time, automatically adapting to the strong nonlinearity of radiation heat transfer in high-temperature section, and dynamically compensating for thermal coupling coefficient drift during equipment operation, effectively solving the problems of distortion and excessively strong or weak compensation signal in high-temperature section of traditional linear static models, and realizing dynamic and accurate cancellation of thermal coupling interference.
[0023] (2) By combining the adaptive decoupling gain correction factor with the static coupling gain, the calculated feedforward decoupling output signal can compensate for the thermal coupling effect of the main control temperature zone power adjustment on the disturbed temperature zone in real time and accurately. No matter how the main control temperature zone power is adjusted, the temperature of the disturbed temperature zone can stably track the preset process curve, avoiding temperature deviation caused by temperature zone crosstalk. This ensures that each temperature zone, such as the glue removal zone, preheating zone, and high-temperature sintering zone, strictly follows the process temperature requirements of magnetic material sintering. The magnetic properties and micro-grain structure of magnetic materials are highly dependent on the temperature control accuracy of the sintering process. Therefore, accurate temperature zone control can effectively reduce the performance differences between magnetic material products, improve the consistency of batch production, and effectively avoid product quality fluctuations caused by temperature zone interference in traditional methods.
[0024] (3) Dynamic and precise thermal coupling interference compensation avoids production interruptions caused by temperature deviations in the temperature zone, such as shutdown to adjust parameters and rework of unqualified products, ensuring that large-scale continuous production of continuous tunnel kilns or pusher furnaces is not affected; at the same time, the adaptive mechanism reduces model inaccuracies caused by equipment aging and operating condition fluctuations, eliminating the need for periodic shutdowns to recalibrate the decoupling matrix, reducing maintenance workload and downtime losses; in addition, improved product consistency reduces the generation of unqualified products, avoids waste of raw materials and increased production costs, and provides magnetic material manufacturers with a comprehensive solution for precise temperature control, efficient production and low-cost operation and maintenance. Attached Figure Description
[0025] Figure 1 This is a flowchart of a magnetic material sintering control method based on multi-temperature zone monitoring according to an embodiment of the present invention.
[0026] Figure 2 This is a schematic diagram of the distribution of feedforward decoupling compensation signal in a magnetic material sintering control method based on multi-temperature zone monitoring according to an embodiment of the present invention. Detailed Implementation
[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0028] This invention discloses a method for controlling the sintering of magnetic materials based on multi-temperature zone monitoring, referring to... Figure 1 This includes steps S001-S005: S001: Real-time acquisition of power and temperature in the main control temperature zone, as well as the temperature of all disturbed temperature zones in the main control temperature zone.
[0029] Specifically, high-precision thermocouples and power monitoring modules deployed in each temperature zone of the sintering furnace are used to collect the power and temperature of the main control temperature zone and the temperatures of all disturbed temperature zones within the main control temperature zone in real time. The temperature unit is converted from Celsius to Kelvin. During the system initialization phase, a power step is applied to the main control temperature zone, and the temperature response curves of each disturbed temperature zone are measured. The ratio of the steady-state temperature rise to the power step is used as the static coupling gain of the main control temperature zone to the controlled temperature zone. The thermal response time constant is calculated as the dynamic rate parameter of the temperature transition from the initial state to the new steady state after the disturbed temperature zone begins to respond. This parameter is obtained by fitting the temperature response curve of the step test to a first-order inertial element. The heat transfer delay time is calculated as the lag time after the power change in the main control temperature zone is transmitted to the disturbed temperature zone, after which the disturbed temperature zone begins to respond. This delay time is determined by the difference between the moment the power is applied and the moment when the temperature of the disturbed temperature zone first changes significantly during the step test.
[0030] S002: Based on the temperature magnitude of the main control temperature zone, determine the dynamic thermal coupling response residual for each disturbed temperature zone, which is used to characterize the deviation between the actual temperature change rate of the disturbed temperature zone and the theoretical prediction value of the current operating condition.
[0031] It should be noted that the heat transfer mechanisms differ across different temperature ranges. Low temperatures are primarily characterized by conduction and convection, while high temperatures are primarily characterized by radiation. A single model would lead to distortion in the residual calculations. Therefore, this step involves segmenting the model according to the temperature of the main control temperature zone to ensure that the residuals accurately reflect the actual thermal coupling deviations during the sintering process of the magnetic material.
[0032] Specifically, the dynamic thermal coupling response residual satisfies: ; In the formula, Disturbed temperature zone exist The dynamic thermal coupling response residual at time t, Main temperature control zone exist Temperature at any moment For setting a high temperature threshold, exemplified by 600°C, the Celsius needs to be converted to Kelvin for comparison. 600°C = , Disturbed temperature zone exist The rate of temperature change at any given time, through the disturbed temperature region exist Time and The temperature difference at any given time is obtained by dividing by the sampling period. For example, the sampling period is 5 seconds. Main temperature control zone To the disturbed temperature zone Thermal response time constant, Main temperature control zone To the disturbed temperature zone The heat transfer delay time, For the set main control temperature zone For controlled temperature zone Static coupling gain, Main temperature control zone exist Power at any moment It is a natural constant. and Main temperature control zone With the disturbed temperature zone exist Temperature at any moment In order to be in The ambient temperature at any given time Stefan's constant in thermodynamics, and is a physical constant. , The main temperature control zone obtained based on the radiative heat transfer formula With the disturbed temperature zone The radiative heat exchange coefficient is obtained through experimental calibration or theoretical estimation: experimental calibration is obtained by inversely solving the measured radiative heat exchange power in a vacuum environment, while theoretical estimation is obtained by multiplying the equivalent emissivity of the two temperature zones by the effective radiative area.
[0033] in, This indicates the disturbed temperature range. The actual heating rate is greater than the model prediction, indicating the presence of additional heat input or a decrease in thermal resistance; if This indicates that the temperature range is disturbed. The actual heating rate is less than the model prediction, possibly due to an increase in the system's equivalent heat capacity or a change in thermal resistance.
[0034] The above-mentioned relationships are strictly anchored to the fundamental laws of thermodynamic heat transfer and the dynamic response theory of control engineering. The core idea is to establish an accurate mapping residual between the actual temperature change in the disturbed temperature region and the predicted value from the theoretical physical model. Traditional calculations often employ a single linear mechanism, which violates the objective physical law that radiative heat transfer increases exponentially to the fourth power under high-temperature conditions, leading to distorted residual calculations. To ensure the model conforms to natural physical laws, this invention performs piecewise physical modeling based on the temperature of the main control temperature region: In the low-temperature range, following the physical mechanism dominated by conduction and convection, a first-order inertial decay term is introduced. Characterizing the dynamic hysteresis of heat transfer, in In the high-temperature range, the Stefan-Boltzmann law is strictly followed, and a natural constant is introduced. The fourth-order temperature difference term characterizes the strong nonlinear radiation features. Through the above modifications, the application of a single mathematical template is abandoned. By accurately fitting the real thermodynamic dominant mechanism of different temperature zones, the real thermal coupling residual caused by the physical aging of the equipment is precisely extracted.
[0035] The subtrahend terms on the right side of the above equation pass through the time constant. The conversions from static gain or radiation coefficient are all uniformly converted to a consistent temperature change rate dimension, i.e., temperature / time. Therefore, the overall... The dimensions are strictly uniform.
[0036] S003: Based on the dynamic thermal coupling response residual, determine the time-varying characteristics of heat transfer from the main control temperature zone to each disturbed temperature zone to characterize the drift of the physical properties of the thermal coupling channel.
[0037] It should be noted that the characteristics of the thermal coupling channel can drift due to equipment aging, deterioration of furnace lining performance, and fluctuations in magnetic material loading. Therefore, this step uses the correlation calculation between residuals and radiative heat flux to more accurately characterize the real-time changes in the heat transfer characteristics of the sintering furnace.
[0038] Specifically, the time-varying characteristics of heat transfer satisfy: ; In the formula, Main temperature control zone To the disturbed temperature zone exist Time-varying characteristics of heat transfer at any given moment Disturbed temperature zone exist The dynamic thermal coupling response residual at time t, Disturbed temperature zone The equivalent heat capacity of the furnace body, used to characterize its heat storage capacity, is obtained by multiplying the furnace material density, the furnace material specific heat capacity, and the temperature zone volume. is the Stefan constant in thermodynamics. The main temperature control zone obtained based on the radiative heat transfer formula With the disturbed temperature zone The radiative heat exchange coefficient, and Main temperature control zone With the disturbed temperature zone exist Temperature at any moment To prevent overparameters with zero denominators, 10% of the radiative heat flux at 1000K is taken to ensure the calculation remains reasonable even in low-temperature regions.
[0039] The time-varying characteristic of heat transfer is essentially a ratio, representing the proportion of the actual deviated heat flow to the current theoretical radiative heat flow. When the time-varying characteristic of heat transfer is positive, it indicates that the conductivity of the thermal coupling channel is enhanced; when the time-varying characteristic of heat transfer is negative, it indicates that the conductivity is weakened.
[0040] S004: Based on the time-varying characteristics of heat transfer and the set sensitivity adjustment coefficient, determine the adaptive decoupling gain correction factor from the main control temperature zone to each disturbed temperature zone.
[0041] It should be noted that static decoupling gain cannot adapt to the time-varying drift of heat transfer characteristics, which can lead to decoupling failure at high temperatures or after long-term operation. Therefore, this step combines historical time-varying characteristics and sensitivity coefficients to generate a correction factor, enabling adaptive adjustment of the decoupling strength in magnetic material sintering scenarios.
[0042] Specifically, the adaptive decoupling gain correction factor satisfies: ; In the formula, Main temperature control zone For the disturbed temperature region exist The adaptive decoupling gain correction factor at time step. The sensitivity adjustment coefficient is set, for example. , The length of the sliding window, for example, , As an index to historical moments, Main temperature control zone To the disturbed temperature zone exist Time-varying characteristics of heat transfer at any given moment It is a natural constant.
[0043] Specifically, the determination of the adaptive decoupling gain correction factor from the main temperature control zone to each disturbed temperature zone also includes noise suppression processing: When the absolute value of the time-varying heat transfer characteristic is less than a preset noise threshold, the adaptive decoupling gain correction factor of the previous moment remains unchanged.
[0044] Specifically, when the time-varying characteristic of heat transfer is continuously positive, the adaptive decoupling gain correction factor is greater than 1, and the system automatically enhances the decoupling strength; when the time-varying characteristic of heat transfer is continuously negative, the adaptive decoupling gain correction factor is less than 1, and the system automatically weakens the decoupling strength, so that the decoupling strength can be dynamically adjusted with the change of furnace thermal characteristics.
[0045] S005: Using the adaptive decoupling gain correction factor, the preset static coupling gain of the main control temperature zone to the controlled temperature zone, and the power change of the main control temperature zone, calculate the feedforward decoupling output signal of each disturbed temperature zone, and superimpose the feedforward decoupling output signal into the control loop of the disturbed temperature zone to realize dynamic compensation for thermal coupling interference and complete the sintering control of magnetic materials for multi-temperature zone monitoring.
[0046] It should be noted that multi-temperature zone thermal coupling interference can cause the temperature of the disturbed zone to deviate from the sintering process curve, affecting the microstructure and magnetic properties of the magnetic material. Therefore, this step superimposes the dynamically corrected decoupling signal onto the control loop to cancel the interference in real time and ensure the process stability of each sintering temperature zone.
[0047] Specifically, the feedforward decoupling output signal satisfies: ; In the formula, From the main temperature control zone For the disturbed temperature region exist The feedforward decoupling output signal at time 1. Main temperature control zone For the disturbed temperature region exist The adaptive decoupling gain correction factor at time step. For the set main control temperature zone For controlled temperature zone Static coupling gain, Main temperature control zone exist The change in power between the current moment and the previous moment, i.e., the main control temperature zone. exist The difference in power between the current moment and the previous moment. Disturbed temperature zone The influence coefficient of its own temperature change on the relationship with power.
[0048] It should be noted that when multiple main temperature control zones simultaneously generate thermal coupling interference to the same disturbed temperature zone, the algebraic sum of the feedforward decoupling output signals from each main temperature control zone to the disturbed temperature zone is used as the final feedforward decoupling output signal of the disturbed temperature zone.
[0049] like Figure 2 As shown, the horizontal axis represents time in units of 1. The vertical axis represents the feedforward decoupling compensation signal, in units of... As can be seen from the figure, the curve reflects the adaptive adjustment characteristics of the compensation signal. When the power of the main control temperature zone changes or the thermal coupling characteristics drift, such as when the heating element ages or the furnace lining performance fluctuates, the compensation signal dynamically adjusts the amplitude and polarity in real time through the adaptive decoupling gain correction factor. For example, during the power step change stage in the main control temperature zone, the compensation signal responds quickly and outputs a corresponding amplitude cancellation signal to accurately cancel the thermal coupling interference generated by the main control temperature zone through heat conduction, radiation, etc., ensuring the temperature stability of the disturbed temperature zone. This reflects the effectiveness and real-time performance of the feedforward decoupling output signal.
[0050] This invention also discloses a magnetic material sintering control system based on multi-temperature zone monitoring, including a processor and a memory. The memory stores computer program instructions, and when the computer program instructions are executed by the processor, a magnetic material sintering control method based on multi-temperature zone monitoring according to the present invention is implemented.
[0051] The system also includes other components well known to those skilled in the art, such as communication buses and communication interfaces, the settings and functions of which are known in the art and will not be described in detail here.
[0052] The above are all preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made in accordance with the structure, shape and principle of the present invention should be covered within the scope of protection of the present invention.
Claims
1. A method for controlling the sintering of magnetic materials based on multi-temperature zone monitoring, characterized in that, include: Real-time acquisition of power and temperature in the main control temperature zone, as well as the temperature of all disturbed temperature zones in the main control temperature zone; Based on the temperature magnitude of the main control temperature zone, determine the dynamic thermal coupling response residual for each disturbed temperature zone, which characterizes the deviation between the actual temperature change rate of the disturbed temperature zone and the theoretical prediction value under the current operating conditions. Based on the dynamic thermal coupling response residual, the time-varying characteristics of heat transfer from the main control temperature zone to each disturbed temperature zone are determined to characterize the drift of the physical properties of the thermal coupling channel. Based on the time-varying characteristics of heat transfer and the set sensitivity adjustment coefficient, the adaptive decoupling gain correction factor from the main control temperature zone to each disturbed temperature zone is determined. By utilizing the adaptive decoupling gain correction factor, the preset static coupling gain of the main control temperature zone to the controlled temperature zone, and the power change of the main control temperature zone, the feedforward decoupling output signal of each disturbed temperature zone is calculated, and the feedforward decoupling output signal is superimposed on the control loop of the disturbed temperature zone to achieve dynamic compensation for thermal coupling interference and complete the sintering control of magnetic materials with multi-temperature zone monitoring.
2. The magnetic material sintering control method based on multi-temperature zone monitoring according to claim 1, characterized in that, The dynamic thermal coupling response residual satisfies: ； In the formula, Disturbed temperature zone exist The dynamic thermal coupling response residual at time t, Main temperature control zone exist Temperature at any moment The set high temperature threshold, Disturbed temperature zone exist The rate of temperature change at any given time Main temperature control zone To the disturbed temperature zone Thermal response time constant, Main temperature control zone To the disturbed temperature zone The heat transfer delay time, For the set main control temperature zone For controlled temperature zone Static coupling gain, Main temperature control zone exist Power at any moment It is a natural constant. and Main temperature control zone With the disturbed temperature zone exist Temperature at any moment for The ambient temperature at any given time It is the Stefan constant. The main temperature control zone obtained based on the radiative heat transfer formula With the disturbed temperature zone The radiative heat exchange coefficient.
3. The magnetic material sintering control method based on multi-temperature zone monitoring according to claim 2, characterized in that, The thermal response time constant and the heat transfer delay time are obtained as follows: During the system initialization phase, a power step is applied to the main control temperature zone, and the temperature response curve of the disturbed temperature zone is measured. After the disturbed temperature zone starts to respond, the dynamic rate parameter of the temperature transitioning from the initial state to the new steady state is obtained by fitting the temperature response curve of the step test with a first-order inertial element. After the power change in the main control temperature zone is transmitted to the disturbed temperature zone, the disturbed temperature zone begins to show a lag time in temperature response. The difference between the moment when the power is applied and the moment when the temperature of the disturbed temperature zone first changes significantly during the step test is taken as the heat transfer delay time.
4. The magnetic material sintering control method based on multi-temperature zone monitoring according to claim 1, characterized in that, The time-varying characteristics of heat transfer satisfy: ； In the formula, Main temperature control zone To the disturbed temperature zone exist Time-varying characteristics of heat transfer at any given moment Disturbed temperature zone exist The dynamic thermal coupling response residual at time t, Disturbed temperature zone The equivalent heat capacity of the furnace body is used to characterize the heat storage capacity of the furnace body. is the Stefan constant in thermodynamics. The main temperature control zone obtained based on the radiative heat transfer formula With the disturbed temperature zone The radiative heat exchange coefficient, and Main temperature control zone With the disturbed temperature zone exist Temperature at any moment This is a hyperparameter used to prevent the denominator from being zero.
5. The magnetic material sintering control method based on multi-temperature zone monitoring according to claim 1, characterized in that, The adaptive decoupling gain correction factor satisfies: ； In the formula, Main temperature control zone For the disturbed temperature region exist The adaptive decoupling gain correction factor at time step. for Sensitivity adjustment coefficient, The length of the sliding window. As an index to historical moments, Main temperature control zone To the disturbed temperature zone exist Time-varying characteristics of heat transfer at any given moment It is a natural constant.
6. The magnetic material sintering control method based on multi-temperature zone monitoring according to claim 1, characterized in that, The determination of the adaptive decoupling gain correction factor from the main control temperature zone to each disturbed temperature zone also includes noise suppression processing: When the absolute value of the time-varying heat transfer characteristic is less than a preset noise threshold, the adaptive decoupling gain correction factor of the previous moment remains unchanged.
7. The magnetic material sintering control method based on multi-temperature zone monitoring according to claim 1, characterized in that, The feedforward decoupling output signal satisfies: ； In the formula, From the main temperature control zone For the disturbed temperature region exist The feedforward decoupling output signal at time 1. Main temperature control zone For the disturbed temperature region exist The adaptive decoupling gain correction factor at time step. For the set main control temperature zone For controlled temperature zone Static coupling gain, Main temperature control zone exist The change in power between time 1 and the previous time. Disturbed temperature zone The influence coefficient of its own temperature change on the relationship with power.
8. The magnetic material sintering control method based on multi-temperature zone monitoring according to claim 1, characterized in that, When multiple master temperature zones simultaneously generate thermal coupling interference to the same disturbed temperature zone, the algebraic sum of the feedforward decoupling output signals from each master temperature zone to the disturbed temperature zone is used as the final feedforward decoupling output signal of the disturbed temperature zone.
9. A method for controlling the sintering of magnetic materials based on multi-temperature zone monitoring according to claim 1, 2, or 8, characterized in that, The static coupling gain is obtained as follows: During the system initialization phase, a power step is applied to the main control temperature zone, and the temperature response curve of the disturbed temperature zone is measured. The ratio of the steady-state temperature rise to the power step in the temperature response curve is used as the static coupling gain of the master temperature control region to the controlled temperature region.
10. A magnetic material sintering control system based on multi-temperature zone monitoring, characterized in that, include: A processor and a memory, the memory storing computer program instructions that, when executed by the processor, implement a magnetic material sintering control method based on multi-temperature zone monitoring according to any one of claims 1-9.