A method and system for operating and regulating a vacuum medium frequency furnace for gas atomized powder production

Abstract

The present application relates to the technical field of control system, and especially relates to a vacuum medium frequency furnace operation regulation and control method and system for gas atomization powder production. The method comprises the following steps: acquiring the furnace body inclination angle, the actual residual mass of the metal liquid in the crucible and the actual flow rate of the crucible in the gas atomization pouring process of the vacuum medium frequency furnace in real time; determining the crucible erosion index at the current time; determining the fluid sensitivity factor at the current time; determining the dynamic scaling coefficient for adjusting the fuzzy PID controller output gain at the current time; and performing the operation regulation and control of the vacuum medium frequency furnace based on the improved fuzzy PID controller. By constructing the crucible erosion index and the fluid sensitivity factor, the present application dynamically optimizes the fuzzy PID control gain, matches the crucible state change in real time, solves the problem of poor adaptability of the fixed rule, improves the regulation and control precision and stability of the vacuum medium frequency furnace, and ensures the stable operation of the gas atomization powder production process.

Description

Technical Field

[0001] This invention relates to the field of control system technology, and in particular to a method and system for controlling the operation of a vacuum intermediate frequency furnace used in gas atomization powder production. Background Technology

[0002] Gas atomization powder production technology is the core process for preparing high-performance spherical metal powders, such as high-temperature alloys and titanium alloy powders. In gas atomization powder production technology, the vacuum intermediate frequency furnace not only undertakes the melting task, but also needs to pour the molten metal into the tundish or guide tube through the tilting mechanism. In order to ensure the consistency of powder particle size distribution (D50) and sphericity, the process strictly requires that the flow rate of molten metal in the crucible must be kept highly constant, that is, to maintain a constant gas-liquid ratio.

[0003] Existing technologies typically employ cylindrical or irregularly shaped crucibles. When tilted at a constant angular velocity, the outflow of liquid changes nonlinearly. To address this, conventional methods use a fuzzy adaptive proportional-integral-derivative (PID) control strategy, employing a pre-defined rule base to handle the nonlinearity of the tilting process.

[0004] However, the rule base and membership functions of existing fuzzy PID controllers are usually designed offline based on the geometric parameters of standard new crucibles. In actual long-term operation, the inner wall of the crucible will become thinner due to high-temperature melting and erosion, or the volume shape will change due to slag adhesion. The time-varying nature of the crucible's geometric parameters causes the actual flow-angle relationship, i.e., the process gain, to undergo physical drift. Fixed fuzzy rules cannot perceive this physical structural change, resulting in a mismatch between control parameters and actual operating conditions. For example, if the crucible wall becomes thinner and the outflow accelerates, the original control parameters may be adjusted too drastically, which will cause fluctuations in the molten metal flow rate, affecting the accuracy of the operation and control of the vacuum induction furnace, and ultimately leading to unstable powder quality. Summary of the Invention

[0005] To address the problem that the time-varying geometric parameters of the crucible lead to a decrease in the control accuracy of traditional fuzzy PID controllers, which affects the accuracy of operation and regulation of vacuum intermediate frequency furnaces and consequently the stability of powder quality, this invention provides a method and system for operation and regulation of vacuum intermediate frequency furnaces used in gas atomization powder production.

[0006] In a first aspect, the present invention provides a method for controlling the operation of a vacuum intermediate frequency furnace for gas atomization powder production, employing the following technical solution:

[0007] A method for controlling the operation of a vacuum intermediate frequency furnace for gas atomization powder production includes: real-time acquisition of the furnace body tilt angle, the actual remaining mass of molten metal in the crucible, and the actual flow rate of the crucible during the gas atomization casting process; recording the ratio of the actual flow rate of the crucible to the furnace body tilt angle at the current moment as the actual mass change rate at the current moment; determining the crucible erosion index at the current moment based on the weighted integral of the difference between the actual mass change rate and the theoretical mass change rate of a standard new crucible at the corresponding furnace body tilt angle; and determining the crucible erosion index based on the crucible erosion index, the actual remaining mass, and the initial loading mass of molten metal in the crucible. Determine the fluid sensitivity factor at the current moment; based on the difference between the fluid sensitivity factor and the set sensitivity threshold, determine the dynamic scaling factor for adjusting the output gain of the fuzzy PID controller at the current moment; input the deviation between the actual flow rate and the target flow rate of the crucible into the fuzzy PID controller to obtain the control output at the current moment; use the dynamic scaling factor to adjust the control output; and combine it with the speed command value of the tilting motor of the vacuum intermediate frequency furnace when the standard new crucible reaches the target flow rate to obtain the real-time speed command of the tilting motor of the vacuum intermediate frequency furnace at the current moment, so as to realize the operation control of the vacuum intermediate frequency furnace.

[0008] The beneficial effects are as follows: By analyzing the difference between the actual mass change rate and the theoretical mass change rate, an evaluation model for the crucible erosion index is constructed, which can assess the degree of change of crucible geometric parameters in real time, providing a reliable basis for adaptive adjustment of control parameters; by combining the crucible erosion index, actual remaining mass, and initial loading mass, a fluid sensitivity factor is constructed, realizing a comprehensive assessment of the fluid control sensitivity under the current operating conditions, which can more accurately reflect the impact of crucible state changes on control performance; based on the fluid sensitivity factor, the output gain of the fuzzy PID controller is dynamically adjusted, realizing adaptive optimization of control parameters, which can adjust the control intensity in real time according to the degree of crucible erosion, ensuring that the control performance matches the actual operating conditions; this invention effectively solves the problem that fixed fuzzy rules cannot adapt to the time-varying nature of crucible geometric parameters, improves the accuracy and stability of vacuum intermediate frequency furnace operation control, and provides a reliable technical guarantee for the stable control of the gas atomization powder production process.

[0009] Furthermore, the real-time acquisition of the furnace body tilt angle, the actual remaining mass of the molten metal in the crucible, and the actual flow rate of the crucible during the gas atomization casting process of the vacuum intermediate frequency furnace includes: using a weighing sensor to collect the remaining mass of the molten metal in the crucible of the vacuum intermediate frequency furnace in real time; using an absolute encoder to collect the tilt angle data of the furnace body in real time; filtering and denoising the remaining mass and the tilt angle data to obtain the furnace body tilt angle and the actual remaining mass of the molten metal in the crucible during the gas atomization casting process of the vacuum intermediate frequency furnace; and performing differential processing on the actual remaining mass to obtain the actual flow rate of the crucible.

[0010] Furthermore, the filtering and denoising process employs the Kalman filtering algorithm.

[0011] Furthermore, the crucible erosion index satisfies:

[0012] In the formula, For the current moment The crucible erosion index, The length of the sliding time window. For the current moment, Let be the integral variable at time . The differential symbol, For a moment The actual flow rate of the crucible, For a moment The furnace body tilt angle, For the standard new crucible at time The theoretical rate of mass change under the furnace body tilt angle, It is a natural exponential function. A time forgetting factor used to increase the weight of recent data. For the minimum normalization function, It is the absolute value symbol.

[0013] The beneficial effects are as follows: by calculating the weighted integral of the difference between the actual mass change rate and the theoretical mass change rate, an evaluation model for the crucible erosion index is constructed. The time forgetting factor ensures that recent data receives greater weight, and the sliding time window avoids the excessive accumulation of historical data, thus more accurately reflecting the dynamic changes in crucible erosion.

[0014] Furthermore, the fluid sensitivity factor satisfies:

[0015] In the formula, For the current moment Fluid sensitivity factor, For the current moment The crucible erosion index, These are weighting coefficients used to balance the numerical scales of geometric wear characteristics and physical state characteristics. For the current moment The actual remaining mass of the molten metal in the crucible. The initial mass of molten metal charged into the crucible; For the current moment The furnace body tilt angle, This is the geometric phase angle correction value for the crucible outlet used to compensate for the influence of the outlet position on the relationship between the tilt angle and the flow rate. It is a sine function.

[0016] The beneficial effects are as follows: by constructing a square root model that includes the crucible erosion index and the physical state term, a comprehensive evaluation of the fluid sensitivity factor is achieved. The influence of crucible geometric wear and current physical state is considered at the same time. The weighting coefficient ensures a reasonable balance between the two characteristics, and the geometric phase angle correction value compensates for the influence of the outlet position, thereby improving the accuracy of sensitivity evaluation.

[0017] Furthermore, the geometric phase angle correction value satisfies:

[0018] In the formula, This refers to the center height of the liquid outlet of the crucible in the vacuum intermediate frequency furnace. Let be the radius of the crucible in the vacuum intermediate frequency furnace. This refers to the initial furnace body tilt angle during the gas atomization casting process of the vacuum intermediate frequency furnace. It is the arctangent function.

[0019] The beneficial effects are as follows: by constructing an arctangent function that includes the geometric parameters of the outlet, a more accurate calculation of the geometric phase angle correction value is achieved, which effectively compensates for the influence of the outlet position on the relationship between the tilt angle and the flow rate. The removal of the initial tilt angle ensures the relativity of the correction and improves the accuracy of the fluid sensitivity factor calculation.

[0020] Furthermore, the dynamic scaling factor satisfies:

[0021] In the formula, For the current moment The dynamic scaling factor used to adjust the output gain of the fuzzy PID controller. and These are the upper and lower limits of the set scaling factor, respectively. For adjustment Follow Shape parameters that vary in steepness. For the current moment Fluid sensitivity factor, For the set sensitivity threshold, It is a natural exponential function.

[0022] The beneficial effect is that: through The model curve function constructs a dynamic scaling coefficient, which realizes smooth adjustment of the output gain of the fuzzy PID controller. When the fluid sensitivity factor exceeds the threshold, the scaling coefficient converges to the minimum value, reducing the control strength. When the sensitivity factor is below the threshold, the scaling coefficient converges to the maximum value, enhancing the control response and ensuring dynamic matching between the control parameters and the actual working conditions.

[0023] Furthermore, the real-time speed command is obtained by multiplying the dynamic scaling factor with the control output at the current moment, and then adding the product result to the speed command value of the tilting motor of the vacuum intermediate frequency furnace when the standard new crucible reaches the target flow rate, so as to obtain the real-time speed command of the tilting motor of the vacuum intermediate frequency furnace at the current moment.

[0024] Furthermore, the following anomaly handling is also included: In response to the absolute value of the instantaneous rate of change of the actual remaining mass being greater than a set mass threshold, the weighing data is determined to be abnormal, the speed command of the tilting motor of the vacuum induction furnace is fixed to the average value of the previous 5 control cycles, and the flow rate sensor is enabled for cross-calibration; In response to the absolute value of the deviation between the actual flow rate and the target flow rate of the crucible being greater than a set flow rate threshold, the flow rate deviation is determined to be excessive, and the dynamic scaling factor is forcibly set to the upper limit of the scaling factor; In response to the absolute value of the deviation between the angular velocity of the furnace body tilt angle and the real-time speed command being greater than a set speed threshold, the tilting motor of the vacuum induction furnace is determined to be abnormal, the real-time speed command is reduced, and an alarm is triggered.

[0025] Secondly, the present invention provides a vacuum intermediate frequency furnace operation control system for gas atomization powder production, which adopts the following technical solution:

[0026] A vacuum intermediate frequency furnace operation control system for gas atomization powder production includes a processor and a memory. The memory stores computer program instructions, and when the computer program instructions are executed by the processor, the above-mentioned vacuum intermediate frequency furnace operation control method for gas atomization powder production is implemented.

[0027] By adopting the above technical solution, a computer program for the operation and control method of a vacuum intermediate frequency furnace for gas atomization powder production is generated and stored in a memory so that it can be loaded and executed by a processor. A terminal device can then be made based on the memory and processor for convenient use.

[0028] The present invention has the following technical effects:

[0029] (1) By weighted integral of the difference between the actual mass change rate calculated in real time and the theoretical mass change rate of the standard new crucible, the crucible erosion index is constructed. This can more accurately assess the time-varying geometric parameters of the crucible caused by high-temperature melting and slag adhesion, such as thinning of the wall and change of volume and shape. This breaks the limitation of the traditional fuzzy PID controller's offline fixed rules being unable to perceive changes in physical structure, enabling the control system to capture the physical drift of process gain in real time and avoid control deviations caused by mismatch between fixed rules and actual working conditions.

[0030] (2) The fluid sensitivity factor is determined based on the crucible erosion index, the actual remaining mass and the initial charging mass. The dynamic scaling factor is generated by the difference between the fluid sensitivity factor and the sensitivity threshold. The output gain of the fuzzy PID controller is adjusted in real time. For example, when the crucible wall becomes thinner and the outflow speeds up, the fluid sensitivity factor increases and the dynamic scaling factor weakens the control output to avoid excessive adjustment of the original control parameters. When the slag layer adheres and the outflow slows down, the scaling factor strengthens the control output to ensure that the adjustment intensity matches the actual flow rate characteristics, effectively suppresses the fluctuation of the molten metal flow rate, and ensures accurate matching between the control parameters and the real-time operating conditions.

[0031] (3) The combination of dynamic scaling coefficient and fuzzy PID control output enables the real-time speed command of the tilting motor to adapt to the crucible structure change, accurately control the furnace tilt angle to maintain the target flow rate, solve the problem of inaccurate control caused by the time-varying geometric parameters of the crucible in the traditional method, avoid the interference of flow rate fluctuation on the gas atomization powder production process, such as uneven particle size and substandard purity, ensure stable powder quality and improve batch consistency of powder. Attached Figure Description

[0032] Figure 1 This is a flowchart of a method for controlling the operation of a vacuum intermediate frequency furnace for gas atomization powder production according to an embodiment of the present invention.

[0033] Figure 2 This is a schematic diagram illustrating the relationship between sensitivity and dynamic scaling factor in a vacuum intermediate frequency furnace operation control method for gas atomization powder production according to an embodiment of the present invention. Detailed Implementation

[0034] 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.

[0035] This invention discloses a method for controlling the operation of a vacuum intermediate frequency furnace used in gas atomization powder production, referring to... Figure 1 This includes steps S001-S005:

[0036] S001: Real-time acquisition of the furnace body tilt angle, the actual remaining mass of molten metal in the crucible, and the actual flow rate of the crucible during the gas atomization casting process of the vacuum intermediate frequency furnace.

[0037] Specifically, a high-precision sensing environment is established using a high-precision weighing sensor mounted on a furnace support in a vacuum, with the preferred accuracy being... The weighing sensor collects the remaining mass data of the molten metal in the crucible in real time, for example, at a sampling frequency of 5 times per second; simultaneously, an absolute encoder mounted on a tilting shaft in a vacuum, with a preferred resolution, is used. The encoder acquires the furnace body tilt angle. To eliminate high-frequency noise, the acquired time-series data is processed using Kalman filtering. Preferably, the filtering coefficient is preset according to the different materials of the molten metal; for example, for high-temperature alloy materials, the filtering coefficient is set to [value missing]. For titanium alloy materials, the filter coefficient is set to... .

[0038] To obtain an accurate instantaneous flow rate, the weight differential method is used to calculate the real-time actual flow rate of the crucible:

[0039] ;

[0040] In the formula, For the current moment The actual flow rate of the crucible; the negative sign is used to characterize the physical fact that the mass decreases over time. For the current moment The actual remaining mass of the molten metal in the crucible. The differential symbol, This refers to the current moment.

[0041] S002: Determine the crucible erosion index at the current moment.

[0042] It should be noted that this step is to address the difficulty in assessing the time-varying nature of crucible geometry. Since wear on the inner wall of the crucible can cause a physical shift in the relationship between flow rate and angle, this step constructs a crucible erosion index to assess the degree of deviation between the current actual operating conditions and the standard new crucible model.

[0043] The ratio of the actual flow rate of the crucible to the furnace tilt angle at the current moment is recorded as the actual mass change rate at the current moment. The crucible erosion index at the current moment is determined by the weighted integral of the difference between the actual mass change rate and the theoretical mass change rate of a standard new crucible at the corresponding furnace tilt angle.

[0044] Specifically, the crucible erosion index satisfies:

[0045] ;

[0046] In the formula, For the current moment The crucible erosion index directly reflects the severity of crucible geometric drift; the larger the value, the more severe the drift. The length of the sliding time window needs to be determined according to the smelting rhythm, and is usually taken as 1 / 10 of the single-furnace tilting time. For example, if the single-furnace tilting time is 20s, then... Take 2 seconds to ensure that the window contains at least 5 tilt angle sampling points to guarantee the stability of the integration results; The current moment; The integral variable at time step is used for iteration. Historical moments within the interval, covering recent key operating condition data; The differential symbol, For a moment The actual flow rate of the crucible, For a moment The furnace body tilt angle, This represents the actual rate of change in mass under the current operating conditions. For the standard new crucible at time The theoretical mass change rate under the furnace body tilt angle was obtained through fitting the factory test to ensure the consistency between theory and reality. Forgotten items over time, represented as The closer to the current moment This means that the newer the data, the closer the value of this item is to 1, and the higher the weight, thereby reducing the interference of outdated historical data on the judgment of the current geometric state; To increase the weight of recent data, a time forgetting factor was used. Its value was calibrated through offline experiments. Three groups of crucibles with different wear levels (0.2 mm, 0.5 mm, and 0.8 mm) were selected, and flow rate data were collected at the same tilt angle. The data was then fitted using the least squares method. The error in identifying the amount of wear is less than 5%, and the final determination is made. The range of values ​​is ; For the minimum normalization function, It represents the absolute value; through integration, it can capture in real time the geometric characteristic drift caused by the thinning of the wall, which leads to faster outflow, or the adhesion of the slag layer, which leads to slower outflow.

[0047] S003: Determine the fluid sensitivity factor at the current moment.

[0048] It should be noted that in actual smelting processes, the same degree of crucible wear has different effects on flow rate fluctuations under different liquid levels. At high liquid levels, small changes in tilt angle are amplified into significant flow rate fluctuations, while at low liquid levels, the impact is smaller. Therefore, it is necessary to construct a fluid sensitivity factor based on the current liquid level to assess the system's sensitivity to tilt angle changes under the current wear condition and liquid level.

[0049] The fluid sensitivity factor at the current moment is determined based on the crucible erosion index, the actual remaining mass, and the initial charge mass of the molten metal in the crucible.

[0050] Specifically, the fluid sensitivity factor satisfies:

[0051] ;

[0052] In the formula, For the current moment The higher the value of the fluid sensitivity factor, the greater the sensitivity to changes in tilt angle under the current operating conditions, and the greater the operational risk. For the current moment The crucible erosion index; The weighting coefficients used to balance the numerical scales of geometric wear characteristics and physical state characteristics, ensuring comparability of the two indicators when superimposed, are determined through experimental fitting. For example, five groups of operating conditions with different liquid levels ranging from 10% to 90% full furnace are selected, and corresponding flow rate fluctuation data are collected and adjusted. make The correlation with the measured value of flow rate fluctuation is ≥0.9, ultimately... The value is 1.0; For the current moment The actual remaining mass of the molten metal in the crucible; The initial mass of molten metal charged into the crucible; This represents the mass percentage of the remaining molten metal, used to characterize the current liquid level in the crucible. The larger this value, the higher the liquid level. For the current moment The furnace body tilt angle; This is the geometric phase angle correction value for the crucible outlet used to compensate for the influence of the outlet position on the relationship between the tilt angle and the flow rate. , This refers to the center height of the liquid outlet of the crucible in the vacuum intermediate frequency furnace. Let be the radius of the crucible in the vacuum intermediate frequency furnace. The initial furnace body tilt angle during the gas atomization casting process of the vacuum intermediate frequency furnace can be adjusted according to the actual situation. It is the arctangent function; This value is used to characterize whether the current tilt angle is within the main outlet angle range. The larger the value, the higher the outlet efficiency of the molten metal at the current furnace tilt angle, and the stronger the system's sensitivity to changes in tilt angle.

[0053] In summary, when the system is at full capacity, that is... Furthermore, when the furnace body tilt angle is in the main liquid outlet zone, the value of the second term under the square root increases significantly. At this time, even Smaller, the final calculated It will also be at a high level, which means that the system has identified a highly sensitive operating condition with a high liquid level. At this time, even a small motor movement may cause flow rate oscillation, which provides a basis for subsequent compression control gain.

[0054] S004: Determine the dynamic scaling factor used to adjust the output gain of the fuzzy PID controller at the current moment.

[0055] It should be noted that, in order to effectively integrate the physical-level sensitivity analysis results into the fuzzy PID algorithm, this invention does not change the fuzzy membership function itself, i.e., it does not modify the universe of discourse. Instead, it adjusts the output gain of the fuzzy controller to achieve a conservative control in sensitive areas and a flexible control in insensitive areas. Therefore, this step constructs a dynamic scaling factor for the output gain of the fuzzy controller as a link between operating condition analysis and control execution.

[0056] Based on the difference between the fluid sensitivity factor and the set sensitivity threshold, the dynamic scaling factor used to adjust the output gain of the fuzzy PID controller at the current moment is determined, such as... Figure 2 As shown, when the fluid sensitivity factor is below the sensitivity threshold, the dynamic scaling factor is high to strongly adjust the response deviation; when the fluid sensitivity factor is above the sensitivity threshold, the coefficient decreases. Conservative control prevents vibration and achieves adaptive matching of operating conditions.

[0057] Specifically, the dynamic scaling factor satisfies:

[0058] ;

[0059] In the formula, For the current moment The dynamic scaling factor used to adjust the output gain of the fuzzy PID controller has a value range limited to [value range missing]. The range between these values ​​directly determines the adjustment range of the fuzzy control output increment; To and These are the upper and lower limits of the set scaling factor, respectively. This is used to address low-sensitivity operating conditions, ensuring rapid control response to quickly correct flow rate deviations. For example, The value is Ensure flow rate deviation under low-sensitivity operating conditions In this way, deviation correction can be completed within one control cycle. This is used to address highly sensitive operating conditions, limiting the motor's movement amplitude to avoid flow rate oscillations. For example, To ensure the single-time adjustment of motor speed under highly sensitive operating conditions. Effectively suppresses overshoot. For adjustment Follow The shape parameters for the steepness of the change were obtained experimentally and then adjusted. make Exceeding the sensitivity threshold hour, Able to start from within 0.1 seconds The value dropped from 1.2 to The value is 0.3, to quickly adapt to highly sensitive working conditions, therefore... The value is 10; For the current moment The fluid sensitivity factor; The set sensitivity threshold is the key boundary between high-sensitivity and low-sensitivity operating conditions. Its value is obtained based on statistical analysis of multiple furnace experiments, taking into account flow rate fluctuations exceeding allowable values, such as ±0.03 kg / s. The minimum value, for example, The value is 0.4; The natural exponential function is used to construct... The nonlinear mapping relationship in reciprocal form ensures The changes are smooth and continuous, avoiding abrupt changes in control commands.

[0060] In summary, the dynamic scaling factor constructs a system based on... The nonlinear mapping relationship of the function, when In highly sensitive operating conditions, such as a full furnace or severe wear, the exponential term increases rapidly, the denominator becomes larger, and the fractional value approaches the mean. ,final near This achieves the effect of automatic conservative control during high-risk moments; conversely, when That is, under low-sensitivity operating conditions, Quickly recover to This ensures the sensitivity of the control.

[0061] S005: Operation control of vacuum intermediate frequency furnace based on improved fuzzy PID controller.

[0062] It should be noted that the deviation between the real-time flow rate and the target flow rate, as well as the rate of change of the deviation, are input into the fuzzy inference engine to obtain the standardized control increment. Then, the final tilting motor speed command is calculated by combining the dynamic scaling factor. At the same time, in order to cope with sudden abnormal scenarios in actual operation, emergency handling logic for abnormal operating conditions is added to ensure the robustness and stability of the control system.

[0063] The deviation between the actual flow rate and the target flow rate of the crucible is input into the fuzzy PID controller to obtain the control output at the current moment. The control output is adjusted using the dynamic scaling coefficient and combined with the speed command value of the tilting motor of the vacuum intermediate frequency furnace when the standard new crucible reaches the target flow rate to obtain the real-time speed command of the tilting motor of the vacuum intermediate frequency furnace at the current moment, so as to realize the operation control of the vacuum intermediate frequency furnace.

[0064] Specifically, the method for obtaining the real-time speed command is as follows:

[0065] Multiply the dynamic scaling factor by the control output at the current moment, and then add the product to the speed command value of the tilting motor of the vacuum intermediate frequency furnace when the standard new crucible reaches the target flow rate, to obtain the real-time speed command of the tilting motor of the vacuum intermediate frequency furnace at the current moment.

[0066] Specifically, it also includes the following exception handling:

[0067] In response to the actual remaining mass The absolute value of the instantaneous rate of change is greater than the set quality threshold, for example, If the weighing data is found to be abnormal, the speed command of the tilting motor of the vacuum intermediate frequency furnace is fixed to the average value of the previous 5 control cycles and the flow rate sensor is activated for cross-correction.

[0068] In response to the actual flow rate of the crucible With target flow rate The absolute value of the deviation is greater than the set flow rate threshold, for example, If the flow rate deviation is determined to be excessive, the dynamic scaling factor is forcibly set to the upper limit of the scaling factor.

[0069] Response to the furnace body tilt angle angular velocity and the real-time velocity command When the absolute value of the deviation is greater than the set speed threshold, for example, If the tilting motor of the vacuum intermediate frequency furnace is found to be abnormal, the real-time speed command is gradually reduced to 80% of the current value, and an alarm is triggered.

[0070] This invention also discloses a vacuum intermediate frequency furnace operation control system for gas atomization powder making, including a processor and a memory. The memory stores computer program instructions, and when the computer program instructions are executed by the processor, a vacuum intermediate frequency furnace operation control method for gas atomization powder making according to the present invention is implemented.

[0071] 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.

[0072] 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 operation of a vacuum intermediate frequency furnace for gas atomization powder production, characterized in that, include: Real-time acquisition of furnace body tilt angle, actual remaining mass of molten metal in crucible, and actual flow rate of crucible during the gas atomization casting process of vacuum intermediate frequency furnace; The ratio of the actual crucible flow rate to the furnace tilt angle at the current moment is recorded as the actual mass change rate at the current moment. The crucible erosion index at the current moment is determined by the weighted integral of the difference between the actual mass change rate and the theoretical mass change rate of a standard new crucible at the corresponding furnace tilt angle. In the formula, For the current moment The crucible erosion index, The length of the sliding time window. For the current moment, Let be the integral variable at time . The differential symbol, For a moment The actual flow rate of the crucible, For a moment The furnace body tilt angle, For the standard new crucible at time The theoretical rate of mass change under the furnace body tilt angle, It is a natural exponential function. A time forgetting factor used to increase the weight of recent data. For the maximum-minimum normalization function, It is the absolute value symbol; Based on the crucible erosion index, the actual remaining mass, and the initial charge mass of the molten metal in the crucible, determine the fluid sensitivity factor at the current moment. In the formula, For the current moment Fluid sensitivity factor, These are weighting coefficients used to balance the numerical scales of geometric wear characteristics and physical state characteristics. For the current moment The actual remaining mass of the molten metal in the crucible. The initial mass of molten metal charged into the crucible; For the current moment The furnace body tilt angle, This is the geometric phase angle correction value for the crucible outlet used to compensate for the influence of the outlet position on the relationship between the tilt angle and the flow rate. It is a sine function; Based on the difference between the fluid sensitivity factor and the set sensitivity threshold, the dynamic scaling factor used to adjust the output gain of the fuzzy PID controller at the current moment is determined. In the formula, For the current moment The dynamic scaling factor used to adjust the output gain of the fuzzy PID controller. and These are the upper and lower limits of the set scaling factor, respectively. For adjustment Follow Shape parameters that vary in steepness. The set sensitivity threshold; The deviation between the actual flow rate and the target flow rate of the crucible is input into the fuzzy PID controller to obtain the control output at the current moment. The control output is adjusted using the dynamic scaling coefficient and combined with the speed command value of the tilting motor of the vacuum intermediate frequency furnace when the standard new crucible reaches the target flow rate to obtain the real-time speed command of the tilting motor of the vacuum intermediate frequency furnace at the current moment, so as to realize the operation control of the vacuum intermediate frequency furnace.

2. The method for controlling the operation of a vacuum intermediate frequency furnace for gas atomization powder production according to claim 1, characterized in that, The real-time acquisition of the furnace body tilt angle, the actual remaining mass of molten metal in the crucible, and the actual flow rate of the crucible during the gas atomization casting process of the vacuum intermediate frequency furnace includes: The remaining mass of molten metal in the crucible of the vacuum intermediate frequency furnace is collected in real time using a weighing sensor. The tilt angle data of the vacuum intermediate frequency furnace body is collected in real time using an absolute encoder; The remaining mass and tilt angle data are filtered and denoised to obtain the furnace tilt angle and the actual remaining mass of the molten metal in the crucible during the gas atomization casting process of the vacuum intermediate frequency furnace. The actual flow rate of the crucible is obtained by differentiating the actual remaining mass.

3. The method for controlling the operation of a vacuum intermediate frequency furnace for gas atomization powder production according to claim 2, characterized in that, The filtering and denoising process employs the Kalman filtering algorithm.

4. The method for controlling the operation of a vacuum intermediate frequency furnace for gas atomization powder production according to claim 1, characterized in that, The geometric phase angle correction value satisfies: ； In the formula, This refers to the center height of the liquid outlet of the crucible in the vacuum intermediate frequency furnace. Let be the radius of the crucible in the vacuum intermediate frequency furnace. This refers to the initial furnace body tilt angle during the gas atomization casting process of the vacuum intermediate frequency furnace. It is the arctangent function.

5. The method for controlling the operation of a vacuum intermediate frequency furnace for gas atomization powder production according to claim 1, characterized in that, The method for obtaining the real-time speed command is as follows: Multiply the dynamic scaling factor by the control output at the current moment, and then add the product to the speed command value of the tilting motor of the vacuum intermediate frequency furnace when the standard new crucible reaches the target flow rate, to obtain the real-time speed command of the tilting motor of the vacuum intermediate frequency furnace at the current moment.

6. The method for controlling the operation of a vacuum intermediate frequency furnace for gas atomization powder production according to claim 1, characterized in that, It also includes the following exception handling: In response to the absolute value of the instantaneous rate of change of the actual remaining mass being greater than the set mass threshold, the weighing data is determined to be abnormal. The speed command of the tilting motor of the vacuum intermediate frequency furnace is fixed to the average value of the previous 5 control cycles, and the flow rate sensor is enabled for cross-correction. In response to the absolute value of the deviation between the actual flow rate and the target flow rate of the crucible being greater than the set flow rate threshold, it is determined that the flow rate deviation exceeds the limit, and the dynamic scaling factor is forcibly set to the upper limit value of the scaling factor. When the absolute value of the deviation between the angular velocity of the furnace body tilt angle and the real-time speed command is greater than a set speed threshold, it is determined that the tilting motor of the vacuum intermediate frequency furnace is abnormal, the real-time speed command is reduced, and an alarm is triggered.

7. A vacuum intermediate frequency furnace operation control system for gas atomization powder production, characterized in that, include: The processor and memory, wherein the memory stores computer program instructions that, when executed by the processor, implement a method for controlling the operation of a vacuum intermediate frequency furnace for gas atomization powder production according to any one of claims 1-6.

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