Intelligent control method and system for aluminum profile extruding machine based on multi-parameter fusion

Abstract

The invention discloses an intelligent control method and system for an aluminum profile extruder based on multi-parameter fusion, and belongs to the field of non-ferrous metal processing automation control. According to the method, pressure, speed and outlet temperature signals in the extrusion process are collected in real time, a state observer is built based on a rheological model, and an equivalent characteristic parameter Z representing metal microstructure evolution is deduced. Under the condition that it is detected that the pressure change rate is abnormally increased and the outlet temperature change is not responded, the system executes nonlinear compensation control, and instantaneous limited adjustment is conducted on the speed of an extrusion shaft so as to weaken rheological hardening of a die dead zone and maintain a Z parameter within a preset tissue stability interval; and after the outlet temperature responds, the speed is controlled to smoothly return. Through the control mode, under the condition that the hardware cost is not increased, the structure uniformity and the surface quality consistency in the aluminum profile extrusion process are improved.

Description

Technical Field

[0001] This invention relates to the field of non-ferrous metal extrusion processing control technology, specifically to an intelligent control method and system for aluminum profile extrusion presses based on multi-parameter fusion. Background Technology

[0002] In the aluminum profile extrusion process, there is a significant coupling relationship between extrusion speed, extrusion pressure, and metal temperature. Existing isothermal extrusion control typically uses the exit temperature as the main feedback variable, maintaining temperature stability by adjusting the extrusion speed. However, in actual production, the metal temperature signal is significantly affected by thermal inertia, and temperature changes often lag behind changes in the rheological state within the die region.

[0003] When a sudden change in alloy rheological resistance or a local increase in die load occurs during extrusion, the extrusion pressure will change first, while the exit temperature has not yet shown a significant response. In this case, if temperature negative feedback is still relied upon for control, it can easily lead to increased stress fluctuations within the die area, resulting in problems such as uneven microstructure and surface quality fluctuations.

[0004] Therefore, there is an urgent need in the existing technology for a control method and system that can identify and adjust the changes in rheological state during the extrusion process before the temperature signal is received. Summary of the Invention

[0005] The purpose of this invention is to provide an intelligent control method and system for aluminum profile extrusion presses based on multi-parameter fusion. By comprehensively analyzing multiple process parameters such as pressure, speed and temperature, the system can adjust the rheological state of the extrusion process in advance under the condition of temperature signal lag, thereby improving the stability of the extrusion process and the consistency of product quality.

[0006] The above-mentioned technical objective of the present invention is achieved through the following technical solution: an intelligent control method for aluminum profile extrusion press based on multi-parameter fusion, comprising the following steps: A. State perception and feature extraction: Real-time acquisition of pressure signals from the extrusion system. Speed ​​signal and outlet temperature signal And extract the pressure signal High-frequency components are used to obtain the real-time pressure change rate. ; B. Rheological state parameter derivation: Based on the collected parameters, the equivalent characteristic parameters representing the evolution state of the metal microstructure are deduced in real time using a pre-set rheological model. ; C. Heterogeneous asynchronous compensation control: Monitoring the pressure change rate With outlet temperature signal The changing trend of [the value], when the judgment condition is met: Exceeding the first threshold and rate of change When the value is less than the second threshold, a non-monotonic compensation action is performed: Control the extrusion shaft speed instantaneous rise , wherein The value of is such that the shear heat generated in the metal deformation zone is greater than the increase in deformation resistance caused by work hardening, and the The duration is limited by the preset system load safety envelope; The outlet temperature signal Adjust the speed in response to the temperature rise trend. Smoothly return to the target isothermal extrusion rate.

[0007] Furthermore, the equivalent characteristic parameters The preferred method is based on calculations using the Zener-Hollomon model. The value is calculated using the following formula: in, For speed signal The strain rate obtained by mapping The material deformation activation energy, is the gas constant.

[0008] Furthermore, in step A, the pressure signal is extracted using the sliding window first derivative method or wavelet transform. The high-frequency components in a specific frequency band are used to eliminate mechanical noise interference caused by the pulsation of the hydraulic system itself.

[0009] Furthermore, the system load safety envelope in step C includes: the instantaneous total power of the extrusion shaft does not exceed the rated upper limit, and the acceleration duration is... Less than the thermal inertia response time constant of the mold .

[0010] Furthermore, step C introduces an active disturbance rejection control architecture, which treats mold wear and lubrication fluctuations as total disturbances and compensates for them in real time to correct the target isothermal extrusion speed.

[0011] The present invention also provides an intelligent control system for an aluminum profile extrusion press based on multi-parameter fusion to implement the above method, comprising: The multi-dimensional data sensing module is used to collect pressure, speed and temperature signals in real time during the extrusion process. The rheological state observation module is used to deduce equivalent characteristic parameters in real time based on the variation characteristics of the pressure signal and the rheological model. ; The decision control module, which incorporates non-monotonic compensation logic, outputs a speed control for the extrusion shaft during a physical window when pressure increases but temperature does not respond. The instantaneously increasing pulse compensation command uses the system load safety envelope as the output constraint. The drive execution module is used to adjust the opening degree of the proportional valve of the extruder hydraulic system according to the instructions.

[0012] Furthermore, the system also includes a data alignment unit for aligning pressure, velocity, and temperature signals with different physical response frequencies using nanosecond-level timestamps.

[0013] Furthermore, the rheological state observation module includes a mapping table storing rheological data for various aluminum alloy materials, used to select the corresponding rheological parameters based on the current production material. The value is calculated.

[0014] Furthermore, the decision control module determines the outlet temperature. After the ascent begins, the speed is controlled based on the feedback signal of the temperature gradient. The system regresses to the target steady state according to the preset exponential decay curve.

[0015] Compared with the prior art, the beneficial effects of the present invention are: This invention integrates and analyzes multiple process parameters, including extrusion pressure, extrusion speed, and outlet temperature, to construct a rheological state observation model. This model can identify changes in the rheological state of the metal during extrusion before the outlet temperature signal is received. This method enables early perception of the internal state of the extrusion process, reducing the risk of control failure due to temperature signal lag.

[0016] When an abnormal pressure change rate is detected while the outlet temperature remains within a stable range, the extrusion shaft speed is restricted and adjusted. The heat generated by metal shear introduced by the speed change counteracts the rheological hardening within the die region, maintaining the equivalent characteristic parameters representing the microstructure evolution state within a preset stable range. This adjustment method achieves dynamic control of the microstructure stability during the extrusion process without relying on additional heating or cooling devices.

[0017] Furthermore, this invention introduces system load safety constraints during speed adjustment and smoothly returns the extrusion speed to the target state after the outlet temperature responds. This reduces stress fluctuations during extrusion while ensuring equipment operation safety and control process continuity, thereby improving the uniformity of the microstructure of the extruded profile and the consistency of finished product quality. Attached Figure Description

[0018] Figure 1This is a structural block diagram of an intelligent control system for an aluminum profile extrusion press based on multi-parameter fusion, according to the present invention. Figure 2 This is a schematic diagram of the logic flow of an intelligent control method for an aluminum profile extrusion press based on multi-parameter fusion according to the present invention. Detailed Implementation

[0019] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings, so that those skilled in the art can more clearly understand the technical solution and working principle of the present invention.

[0020] like Figure 1 and Figure 2 As shown, the system described in this invention is deployed on the main body of an aluminum profile extrusion press. During the extrusion process, the aluminum alloy ingot is pushed through the die orifice by the extrusion shaft. To achieve accurate rheological state sensing, the system is equipped with a multi-dimensional sensor group. A high-frequency pressure sensor is deployed in the main oil circuit of the hydraulic drive system or at the end of the extrusion shaft, with a sampling frequency of not less than 1000Hz, to capture instantaneous pressure fluctuations during the extrusion process. The speed measurement module adopts a non-contact speed measurement module, such as a laser Doppler velocimeter, which directly illuminates the profile outlet surface to obtain the actual outflow velocity of the profile. This method eliminates speed measurement errors caused by mechanical transmission backlash. The outlet temperature is detected using a dual-color infrared thermometer, which calculates the temperature by measuring the ratio of radiant energy in two adjacent bands, thus eliminating the influence of fluctuations in the emissivity of the aluminum surface and environmental interference on the accuracy of temperature measurement.

[0021] Acquired pressure signal Speed ​​signal and outlet temperature signal The signal is transmitted to a multi-source data synchronization processor. Because the propagation speed of the pressure wave, the physical transport speed of the profile flow, and the response time of infrared thermography differ by orders of magnitude, the multi-source data synchronization processor employs a nanosecond-level timestamp alignment algorithm to compensate for the signal phase difference caused by different physical transmission paths. Simultaneously, the processor uses a wavelet transform algorithm to decompose the original pressure signal, separating high-frequency components within a preset frequency range (e.g., between 10Hz and 50Hz). These components reflect the viscoplastic dissipation work instability of the metal flow in the mold area, thereby eliminating noise interference generated by the pulsation of the hydraulic system itself, and thus obtaining an accurate real-time pressure change rate. .

[0022] The synchronized data enters the rheological state observer. This observer internally stores rheological mapping tables for different alloy series. The observer combines the current velocity... (converted to strain rate) ) and absolute temperature According to the formula: Real-time simulation of equivalent characteristic parameters Here This represents the deformation activation energy of the material. This is the gas constant. The role of the observer is to transform apparent physical parameters into equivalent characteristic indices reflecting internal rheological trends. When When the value remains within the preset range, it is determined that the dynamic recovery and work hardening of the metal in the deformation zone are in equilibrium.

[0023] The decision control module is the core logic processing unit of this system. It incorporates non-monotonic compensation logic to handle operating conditions that conventional feedback control cannot cover. When the rheological state observer determines the pressure change rate... Exceeding the first threshold This indicates a sudden increase in rheological resistance inside the mold; if the outlet temperature is at this time... rate of change Less than the second threshold (That is, the temperature is in a quasi-stationary state), indicating that the internal load fluctuations have not yet been transmitted to the outlet temperature measurement point. At this time, the decision control module determines that there is controlled lag, and then suspends the conventional deceleration control logic based on the outlet temperature, and instead sends a pulse-type acceleration command to the pump station proportional valve controller.

[0024] During this acceleration action, the speed increment The value is set based on the rheological properties of the material. The physical mechanism of the acceleration is the shear heat generation effect during the plastic deformation process of metal. When the speed... During instantaneous lifting, the rate at which energy dissipation work in the deformation zone is converted into heat energy accelerates. This instantaneously generated controlled heat input can compensate for the hardening effect caused by the limited flow velocity. Through this regulatory logic of compensating for heat energy with mechanical energy, the flow stress of the metal is adjusted at a physical level before the outlet temperature gauge detects a temperature change, thus controlling the pressure. The upward trend has been curbed.

[0025] To ensure operational safety, the decision control module monitors the system load safety envelope in real time during the acceleration process. This envelope defines the upper limit of the instantaneous total power of the extrusion shaft and sets the acceleration duration. It should be less than the thermal inertia response time constant of the mold. This means that the acceleration is a restricted action designed to induce a short-term, controlled heat input to offset stress fluctuations. As heat is conducted from inside the mold to the outlet, a dual-color infrared thermometer detects the temperature rise trend. Exceeding the second threshold The system determined that the thermal balance had been reconstructed. Subsequently, the decision control module controlled the pump station's proportional valve controller to guide the speed. The extrusion speed is smoothly returned to the target isothermal extrusion speed. This return process employs gradual adjustment to avoid secondary pressure shocks caused by sudden speed drops.

[0026] Taking the production process of 6061 series aluminum alloy profiles as an example, in the later stages of the extrusion stroke (e.g., when the remaining ingot length is between 100mm and 150mm), due to uneven heat exchange, localized increases in rheological resistance can easily lead to pressure jumps. In this embodiment, a multi-source data synchronization processor monitors the pressure signal. When determining the rate of change of pressure If the rate of change exceeds a preset threshold range for multiple consecutive sampling periods (e.g., a set value within the range of 3.0 MPa / s to 6.0 MPa / s), and the outlet temperature at this time... When the gradient change is within the quasi-steady-state range, the decision control module determines that stress instability exists. Within the preset response window period after the pressure slope jumps, the proportional valve of the control pump station drives the extrusion speed. Adjust in steps according to a preset ratio (e.g., a setting within the range of 5% to 15%).

[0027] Data monitoring revealed that, in the short period following the acceleration, the change in the shear heat generation rate within the deformation zone caused a temperature rise that offset the increase in rheological resistance, resulting in a decrease in the total extrusion pressure. A reversal and decline occurred, achieving a nonlinear compensation effect. Subsequently, the outlet temperature... A slight increase occurs due to heat conduction. Once a temperature rise signal is detected, the system's guiding speed smoothly recovers. Comparative testing shows that using this method significantly improves the average grain size variation of the profile cross-section, characterizing the uniformity of the microstructure. The parameter fluctuation range has been significantly narrowed, effectively improving the texture defects on the profile surface caused by pressure pulsation.

[0028] The system described in this invention also integrates an active disturbance rejection control architecture to handle trend-based disturbances such as mold wear. The observer in the decision control module can estimate disturbances that cannot be directly measured by sensors in real time and perform real-time offsetting in the output command. In this way, the system can handle instantaneous rheological fluctuations and ensure consistent performance during continuous production. The parameters are maintained within the target range. The entire control system requires no additional hardware and improves the extrusion quality of the profiles through parameter fusion and asynchronous adjustment.

[0029] This specific embodiment is merely an explanation of the present invention and is not intended to limit the invention. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they are within the scope of the claims of the present invention.

Claims

1. A smart control method for an aluminum profile extrusion press based on multi-parameter fusion, characterized in that, Includes the following steps: A. State perception and feature extraction: Real-time acquisition of pressure signals from the extrusion system. Speed ​​signal and outlet temperature signal And extract the pressure signal High-frequency components are used to obtain the real-time pressure change rate. ; B. Rheological state parameter derivation: Based on the collected parameters, the equivalent characteristic parameters representing the evolution state of the metal microstructure are deduced in real time using a pre-set rheological model. ; C. Heterogeneous asynchronous compensation control: Monitoring the pressure change rate With outlet temperature signal The changing trend of [the value], when the judgment condition is met: Exceeding the first threshold and rate of change When the value is less than the second threshold, a non-monotonic compensation action is performed: Control the extrusion shaft speed instantaneous rise , wherein The value of is such that the shear heat generated in the metal deformation zone is greater than the increase in deformation resistance caused by work hardening, and the The duration is limited by the preset system load safety envelope; The outlet temperature signal Adjust the speed in response to the temperature rise trend. Smoothly return to the target isothermal extrusion rate.

2. The intelligent control method for an aluminum profile extrusion press based on multi-parameter fusion according to claim 1, characterized in that: The equivalent characteristic parameters The preferred method is based on calculations using the Zener-Hollomon model. The value is calculated using the following formula: in, For speed signal The strain rate obtained by mapping The material deformation activation energy, is the gas constant.

3. The intelligent control method for an aluminum profile extrusion press based on multi-parameter fusion according to claim 1, characterized in that: In step A, the pressure signal is extracted using the sliding window first-order derivative method or wavelet transform. The high-frequency components in a specific frequency band are used to eliminate mechanical noise interference caused by the pulsation of the hydraulic system itself.

4. The intelligent control method for an aluminum profile extrusion press based on multi-parameter fusion according to claim 1, characterized in that: The system load safety envelope in step C includes: the instantaneous total power of the extrusion shaft does not exceed the rated upper limit, and the acceleration duration is... Less than the thermal inertia response time constant of the mold .

5. The intelligent control method for an aluminum profile extrusion press based on multi-parameter fusion according to claim 1, characterized in that: Step C also introduces an active disturbance rejection control architecture, which treats mold wear and lubrication fluctuations as total disturbances and performs real-time compensation to correct the target isothermal extrusion speed.

6. A multi-parameter fusion-based intelligent control system for an aluminum profile extrusion press that implements the method of any one of claims 1 to 5, characterized in that, include: The multi-dimensional data sensing module is used to collect pressure, speed and temperature signals in real time during the extrusion process. The rheological state observation module is used to deduce equivalent characteristic parameters in real time based on the variation characteristics of the pressure signal and the rheological model. ; The decision control module, which incorporates non-monotonic compensation logic, outputs a speed control for the extrusion shaft during a physical window when pressure increases but temperature does not respond. The instantaneously increasing pulse compensation command uses the system load safety envelope as the output constraint. The drive execution module is used to adjust the opening degree of the proportional valve of the extruder hydraulic system according to the instructions.

7. The intelligent control system for an aluminum profile extrusion press based on multi-parameter fusion according to claim 6, characterized in that: The system also includes a data alignment unit for aligning pressure, velocity, and temperature signals with different physical response frequencies using nanosecond-level timestamps.

8. The intelligent control system for an aluminum profile extrusion press based on multi-parameter fusion according to claim 6, characterized in that: The rheological state observation module includes a mapping table storing rheological data for various aluminum alloy materials, used to select the corresponding rheological parameters based on the current production material. The value is calculated.

9. The intelligent control system for an aluminum profile extrusion press based on multi-parameter fusion according to claim 6, characterized in that: The decision control module determines the outlet temperature. After the ascent begins, the speed is controlled based on the feedback signal of the temperature gradient. The system regresses to the target steady state according to the preset exponential decay curve.

Images