CN-122015518-A - Magnetic material sintering control method and system based on multi-temperature-zone monitoring

CN122015518ACN 122015518 ACN122015518 ACN 122015518ACN-122015518-A

Abstract

The invention relates to the technical field of industrial control, in particular to a magnetic material sintering control method and system based on multi-temperature zone monitoring. The method comprises the steps of collecting power and temperature of a main control temperature area and temperatures of all disturbed temperature areas in real time, calculating dynamic thermal coupling response residual errors of all disturbed temperature areas based on the temperatures of the main control temperature areas, determining heat transfer time-varying characteristics according to the dynamic thermal coupling response residual errors, solving self-adaptive decoupling gain correction factors by combining sensitivity adjustment coefficients, calculating feedforward decoupling output signals by utilizing the correction factors, static coupling gains and power variation of the main control temperature areas, and superposing the feedforward decoupling output signals on a control loop of the disturbed temperature areas. The invention effectively inhibits the thermal coupling interference of multiple temperature areas, dynamically senses the physical characteristic drift of the thermal coupling channel, improves the decoupling control precision under the high-temperature nonlinear working condition, and enhances the magnetic material sintering temperature control precision and the product consistency.

Inventors

GAO JINCHANG
CHANG ZHENJIANG
LingHu Ruomeng
CHENG HAIBO

Assignees

山西东睦磁电有限公司

Dates

Publication Date: 20260512
Application Date: 20260410

Claims (10)

1. The magnetic material sintering control method based on multi-temperature zone monitoring is characterized by comprising the following steps of: Collecting the power and the temperature of a main control temperature area in real time, and collecting the temperature of all disturbed temperature areas of the main control temperature area; Determining dynamic thermal coupling response residual errors of deviations between actual temperature change rates of the disturbed temperature areas and theoretical predicted values of current working conditions according to the temperature of the main control temperature areas; according to the dynamic thermal coupling response residual error, determining heat transfer time-varying characteristics from the main control temperature region to each disturbed temperature region for representing the physical characteristic drift of the thermal coupling channel; according to the heat transfer time-varying characteristics and the set sensitivity adjustment coefficients, determining self-adaptive decoupling gain correction factors from the main control temperature zone to each disturbed temperature zone; And calculating feedforward decoupling output signals of each disturbed temperature zone by using the self-adaptive decoupling gain correction factor, the static coupling gain of the preset main control temperature zone to the controlled temperature zone and the power variation of the main control temperature zone, and overlapping the feedforward decoupling output signals into a control loop of the disturbed temperature zone to realize dynamic compensation of thermal coupling interference and complete magnetic material sintering control of monitoring the multiple temperature zones.
2. The magnetic material sintering control method based on multi-temperature zone monitoring according to claim 1, wherein the dynamic thermal coupling response residual error satisfies: ; In the formula, As disturbed temperature zone At the position of The dynamic thermal coupling response residuals at the moment in time, Is the main control temperature zone At the position of The temperature at the moment of time is, In order to set the high temperature threshold value, As disturbed temperature zone At the position of The rate of change of temperature at the moment in time, Is the main control temperature zone To the disturbed temperature zone Is used for the thermal response time constant of (a), Is the main control temperature zone To the disturbed temperature zone Is used for the heat transfer delay time of the (c), Is a set main control temperature zone For controlled temperature zone Is used for the static coupling gain of (a), Is the main control temperature zone At the position of The power of the moment in time, Is a natural constant which is used for the production of the high-temperature-resistant ceramic material, And (3) with Respectively is a main control temperature zone And disturbed temperature zone At the position of The temperature at the moment of time is, Is that The ambient temperature at the moment in time, Is a constant of Stefan, Is a main control temperature zone obtained based on a radiation heat exchange formula And disturbed temperature zone Is used for the radiation heat exchange coefficient of the (a).
3. The method for controlling sintering of magnetic materials based on multi-temperature zone monitoring according to claim 2, wherein the thermal response time constant and the thermal transfer delay time are obtained by the following ways: in the system initialization stage, applying a power step to a main control temperature region, measuring a temperature response curve of a disturbed temperature region, and after the disturbed temperature region starts temperature response, transitioning the temperature from an initial state to a dynamic rate parameter of a new steady state, and fitting the temperature response curve through a first-order inertia link by using a step test to obtain the thermal response time constant; and after the power change of the main control temperature region is transferred to the disturbed temperature region, the disturbed temperature region starts to have a lag time of temperature response, and a difference value between the power application time in the step test and the first significant change time of the temperature of the disturbed temperature region is taken as the heat transfer delay time.
4. The method for controlling sintering of magnetic materials based on multi-temperature zone monitoring according to claim 1, wherein the heat transfer time-varying characteristics satisfy: ; In the formula, Is the main control temperature zone To the disturbed temperature zone At the position of The time-of-day heat transfer time-varying characteristics, As disturbed temperature zone At the position of The dynamic thermal coupling response residuals at the moment in time, As disturbed temperature zone A furnace body equivalent heat capacity for representing the heat storage capacity of the furnace body, Is a Stefan constant in thermodynamics, Is a main control temperature zone obtained based on a radiation heat exchange formula And disturbed temperature zone Is used for the radiation heat exchange coefficient of (a), And (3) with Respectively is a main control temperature zone And disturbed temperature zone At the position of The temperature at the moment of time is, Is a super parameter for preventing denominator from being zero.
5. The method for controlling sintering of magnetic materials based on multi-temperature zone monitoring according to claim 1, wherein the adaptive decoupling gain correction factor satisfies: ; In the formula, Is the main control temperature zone For disturbed temperature zone At the position of The adaptive decoupling gain correction factor for time of day, Is that Is used for the sensitivity adjustment coefficient of the (c), For the length of the sliding window, For the index of the time of the history, Is the main control temperature zone To the disturbed temperature zone At the position of The time-of-day heat transfer time-varying characteristics, Is a natural constant.
6. The method for controlling sintering of magnetic materials based on multi-temperature-zone monitoring according to claim 1, wherein the determining the adaptive decoupling gain correction factor from the main control temperature zone to each disturbed temperature zone further comprises a noise suppression process: And in response to the absolute value of the heat transfer time-varying characteristic being smaller than a preset noise threshold, keeping the adaptive decoupling gain correction factor unchanged at the last moment.
7. The method for controlling sintering of magnetic materials based on multi-temperature zone monitoring according to claim 1, wherein the feedforward decoupling output signal satisfies: ; In the formula, Is from the main control temperature zone For disturbed temperature zone At the position of The feed forward of time of day decouples the output signal, Is the main control temperature zone For disturbed temperature zone At the position of The adaptive decoupling gain correction factor for time of day, Is a set main control temperature zone For controlled temperature zone Is used for the static coupling gain of (a), Is the main control temperature zone At the position of The amount of power change from time to time and from the previous time, As disturbed temperature zone Influence coefficient of temperature change and power relation of the self.
8. The method of claim 1, wherein when there are a plurality of main control temperature areas and thermal coupling interference is generated on the same disturbed temperature area, the algebraic sum of feedforward decoupling output signals from each main control temperature area to the disturbed temperature area is used as the final feedforward decoupling output signal of the disturbed temperature area.
9. The method for controlling sintering of magnetic materials based on multi-temperature-zone monitoring according to claim 1, 2 or 8, wherein the static coupling gain is obtained by the following steps: In the system initialization stage, applying a power step to a main control temperature zone, and measuring a temperature response curve of a disturbed temperature zone; and taking the ratio of the steady-state temperature rise of the temperature response curve to the power step as the static coupling gain of the main control temperature zone to the controlled temperature zone.
10. A magnetic material sintering control system based on multi-temperature zone monitoring, comprising 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 of claims 1-9.

Description

Magnetic material sintering control method and system based on multi-temperature-zone monitoring Technical Field The invention relates to the technical field of industrial control, in particular to a magnetic material sintering control method and system based on multi-temperature zone monitoring. Background Magnetic materials, particularly high-performance neodymium iron boron permanent magnetic materials and ferrite magnetic materials, are key basic materials in the modern industry, and the magnetic performance and microscopic grain structure of the magnetic materials are highly dependent on the temperature control precision in the sintering process. In industrial production, in order to meet the requirement of large-scale continuous production, a continuous tunnel kiln or a push plate furnace is generally adopted, and such equipment spatially divides a hearth into a plurality of continuous temperature areas, such as a glue discharging area, a preheating area, a high-temperature sintering area and a cooling area, and each temperature area is required to strictly control the temperature according to a specific process curve. In actual operation, because adjacent temperature areas are physically communicated, ideal adiabatic isolation is lacked, so that serious thermal coupling interference phenomenon occurs, namely, the power adjustment of one temperature area can obviously change the temperature of the adjacent temperature area through heat conduction, convection, radiation and other modes. At present, a feedforward decoupling control method based on a static model is generally adopted, and a fixed decoupling matrix is calculated for compensation by testing a transfer function in a steady state in advance. However, when the traditional method based on the linear superposition principle is used for sintering magnetic materials, heat radiation becomes a dominant heat transfer mechanism along with the rise of furnace temperature, radiation heat flow is in direct proportion to the fourth power of temperature according to the Stefan-Boltzmann law, a linear decoupling model calibrated based on a single working condition is severely distorted at a high temperature section due to high nonlinearity, meanwhile, along with the long-term operation of equipment, the aging of a heating element, the reduction of the heat insulation performance of a furnace lining and the fluctuation of the loading capacity can all cause the drift of an actual heat coupling coefficient, a fixed static model cannot sense the change, and a compensation signal is excessively strong or weak, so that the consistency of magnetic material products is affected. Disclosure of Invention The invention provides a magnetic material sintering control method and system based on multi-temperature-zone monitoring, aiming at solving the problem that the traditional static decoupling model cannot adapt to high-temperature nonlinearity and parameter time-varying drift, so that the temperature control precision is poor and the consistency of magnetic material products is affected. In a first aspect, the present invention provides a magnetic material sintering control method based on multi-temperature area monitoring, which adopts the following technical scheme: A magnetic material sintering control method based on multi-temperature area monitoring comprises the steps of collecting power and temperature of a main control temperature area and temperatures of all disturbed temperature areas of the main control temperature area in real time, determining dynamic thermal coupling response residual errors of deviation between actual temperature change rates of the disturbed temperature areas and theoretical predicted values of current working conditions according to the temperatures of the main control temperature areas, determining heat transfer time-varying characteristics of the main control temperature areas to the disturbed temperature areas for representing physical characteristic drift of a thermal coupling channel according to the dynamic thermal coupling response residual errors, determining adaptive decoupling gain correction factors of the main control temperature areas to the disturbed temperature areas according to the heat transfer time-varying characteristics and set sensitivity adjustment coefficients, calculating feedforward decoupling output signals of the disturbed temperature areas according to the adaptive decoupling gain correction factors and static coupling gains of the main control temperature areas to controlled temperature areas, and power change amounts of the main control temperature areas, and adding the feedforward decoupling output signals to a control loop of the disturbed temperature areas to achieve dynamic compensation of the heat transfer time-varying characteristics to the heat transfer time-varying characteristics, and the multi-temperature monitoring material sintering control is completed. The method has the advantages that t