Powder laser sintering 3D printing equipment powder global heating temperature control method

Abstract

The application discloses a powder global heating temperature control method for a powder laser sintering 3D printing device, which synchronously collects three types of data, i.e., powder bed temperature, accumulation morphology and environmental heat exchange, and fuses the three types of data into comprehensive monitoring data; the powder bed is divided into independent temperature control field domains which are seamlessly connected, basic heating parameters are matched in combination with a sintering process; pre-compensation of heating power is completed according to the thermal hysteresis characteristics of the powder and a special formula, and secondary parameter correction is performed on the edge field domains; and global heating is implemented by adopting a differentiated mode of central constant heat supply and edge pulse heat supply. In the heating process, a multi-level threshold group is relied on to determine the temperature state, independent adjustment instructions are generated to dynamically optimize the heating parameters, and through cyclic closed-loop operation, external disturbances such as laser and powder laying are offset. The application breaks through the limitation of traditional single temperature measurement and post-feedback temperature control, effectively eliminates the temperature control blind area, solves the problems of powder thermal hysteresis, global temperature unevenness, edge heat dissipation imbalance and the like, and significantly improves the stability of the powder temperature field.

Description

Technical Field

[0001] This invention belongs to the field of plastic molding technology, and in particular relates to a method for temperature control of powder global heating in powder laser sintering 3D printing equipment. Background Technology

[0002] Selective laser sintering (SLS) 3D printing technology relies on laser sintering of powder layer by layer to form parts. The uniformity and stability of the temperature field across the entire powder bed directly determine the quality of the formed parts, which is a core technical point in this field. Currently, various powder heating and temperature control solutions have been developed in the industry. The mainstream technology generally adopts a single temperature sensor acquisition method combined with feedback closed-loop control logic, and uses simple area division to achieve powder temperature regulation. In practical industrial applications, this has two shortcomings:

[0003] Firstly, existing temperature control systems rely solely on powder surface temperature for regulation, failing to consider powder deposition morphology and chamber heat transfer conditions for coordinated control. The powder bed exhibits morphological characteristics such as uneven particle density and varying deposition thickness, leading to inconsistent local thermal resistance. Simultaneously, the flow of protective gas within the printing chamber and thermal radiation from the chamber walls continuously remove heat from the powder. Traditional solutions ignore these coupled interference factors of morphology and heat transfer, relying only on single-point / layer temperature data for passive temperature adjustment. This fails to anticipate local temperature deviations, resulting in significant differences in heating rates and steady-state temperatures across different parts of the powder bed. Overall temperature consistency is difficult to guarantee, especially in large-size powder beds and high-melting-point polymer powder sintering scenarios, leading to frequent defects such as part warping and poor interlayer bonding.

[0004] Secondly, existing methods employ either a uniform heating mode or a crude, block-based zone heating approach. On one hand, conventional zone heating methods have blind spots in area connections, failing to achieve true, comprehensive temperature control of the powder bed. On the other hand, they do not differentiate between the heat dissipation differences at the center, edges, and corners of the powder bed, relying solely on post-heating temperature measurement for adjustment. Powder materials inherently possess thermal hysteresis; post-heating adjustments cannot offset the temperature delay caused by thermal inertia. Combined with the fact that heat loss rates at edges and corners are much higher than in the center, this easily leads to lower edge temperatures and overshooting at the center. Simultaneously, instantaneous thermal and mechanical disturbances generated by laser scanning and powder-laying mechanism movements cannot be suppressed in time, further exacerbating temperature field fluctuations and severely restricting the forming accuracy and yield of 3D printed products. Summary of the Invention

[0005] The purpose of this invention is to provide a method for temperature control of powder global heating in powder laser sintering 3D printing equipment, so as to solve the problems mentioned in the background art.

[0006] In view of this, the present invention provides a method for temperature control of powder global heating in powder laser sintering 3D printing equipment, comprising the following steps:

[0007] Temperature data, powder deposition morphology data, and environmental heat transfer data are collected throughout the powder bed area and integrated to obtain comprehensive monitoring data for the entire area.

[0008] Based on the spatial distribution characteristics of the powder bed, several seamlessly connected independent temperature control fields are divided, and the basic heating parameters of each temperature control field are matched in combination with the sintering process parameters.

[0009] By utilizing the thermal response characteristics of powder, the basic heating parameters are pre-compensated and calculated to obtain the real-time heating parameters of each temperature control field.

[0010] The distributed heating components are driven to synchronously heat the entire powder bed according to real-time heating parameters.

[0011] Continuously collect real-time temperature data across the entire heating process and compare the real-time temperature data with a preset multi-level temperature control threshold group;

[0012] Based on the comparison results, independent adjustment commands are generated for each temperature-controlled field to dynamically adjust the heating status of each field.

[0013] The process of data acquisition, parameter comparison, and status adjustment is executed in a loop to achieve continuous closed-loop temperature control for the entire heating range of the powder bed.

[0014] In a further embodiment of the present invention, the collection of temperature data, powder accumulation morphology data and environmental heat transfer data over the entire range of the powder bed, and the integration of these data to obtain comprehensive monitoring data over the entire range, includes: deploying a three-dimensional sensor array in the horizontal direction and the depth thickness direction of the powder bed, and collecting multiple temperature values ​​at the surface, middle layer and bottom layer of the powder respectively to form a comprehensive temperature dataset.

[0015] By scanning the powder bed surface with a visual acquisition device, the local powder accumulation thickness and particle density are identified, and a powder accumulation morphology dataset is obtained.

[0016] Collect the protective gas flow rate, cavity wall temperature, and ambient radiative heat transfer coefficient inside the printing cavity to obtain an ambient heat transfer dataset;

[0017] The global temperature dataset, powder accumulation morphology dataset, and environmental heat transfer dataset are aligned along the time axis and then merged and packaged into a comprehensive global monitoring dataset.

[0018] In a further embodiment of the present invention, the step of dividing the powder bed into several seamless independent temperature control fields based on the spatial distribution characteristics of the powder bed, and matching the basic heating parameters of each temperature control field with the sintering process parameters, includes: dividing the entire powder bed into multiple independent temperature control fields in the form of equal area units, with no blank areas between adjacent temperature control fields and the boundaries of each other being close together;

[0019] The laser sintering power, single-layer powder thickness, scanning travel speed, and single sintering time are read as sintering process parameters.

[0020] Based on the sintering temperature range and thermal conductivity of the powder to be processed, the basic heating power, basic heating time, and basic thermal radiation angle are configured for each independent temperature control field, and the basic heating parameters corresponding to each field are determined.

[0021] In a further embodiment of this invention, the pre-compensation calculation of basic heating parameters using the thermal response characteristics of powder to obtain real-time heating parameters for each temperature-controlled field includes: calculating the thermal hysteresis coefficient λ of the powder in a single field based on the powder particle size and packing porosity, and combining it with the environmental heat transfer coefficient α and the basic heating power P0 of the field, using the formula:

[0022] The pre-compensated heating power P is calculated, where λ is the difference between the measured temperature of the field and the theoretical reference temperature.

[0023] Based on the influence of heat transfer between adjacent fields, secondary parameter correction is performed on the temperature control field located at the edge of the powder bed, and finally the real-time heating parameters of all temperature control fields are output.

[0024] In a further embodiment of the present invention, the step of driving the distributed heating components to synchronously perform heating operations on the entire powder bed according to real-time heating parameters includes:

[0025] The real-time heating parameters corresponding to each temperature control field are sent one by one to each heating subunit in the distributed heating component;

[0026] The heating subunit corresponding to the central area of ​​the powder bed adopts a constant output mode for continuous heating, while the heating subunit corresponding to the edge area of ​​the powder bed adopts a periodic pulse output mode for intermittent heating.

[0027] All heating subunits maintain a unified operating sequence, ensuring that the heat input rhythm across the entire powder bed remains synchronized.

[0028] In a further embodiment of the present invention, the continuous acquisition of real-time temperature data across the entire heating process is used to compare the real-time temperature data with a preset multi-level temperature control threshold group, including: a preset low-temperature compensation threshold, a standard constant temperature threshold, and a high-temperature warning threshold, which together constitute a multi-level temperature control threshold group.

[0029] The real-time temperature of each independent temperature-controlled field is extracted one by one, and the temperature value of a single field is compared with the threshold values ​​in the multi-level temperature control threshold group to determine the magnitude of the temperature value.

[0030] Record the judgment results for each temperature control field and the magnitude of temperature deviation from the threshold to form a global temperature judgment result set.

[0031] In a further embodiment of the present invention, the step of generating field-independent adjustment instructions based on the comparison results to dynamically adjust the heating state of each temperature-controlled field includes: generating a step-wise power increase instruction when the real-time temperature of the temperature-controlled field is lower than the low-temperature compensation threshold.

[0032] When the real-time temperature of the temperature-controlled field exceeds the high-temperature warning threshold, a gradient power reduction command is generated.

[0033] When the real-time temperature of the temperature control field is within the standard constant temperature threshold range, the current heating parameters remain unchanged;

[0034] All field adjustment commands are sorted and integrated according to spatial location to generate complete field-independent adjustment commands, and the operating parameters of the corresponding heating sub-units are changed according to the commands.

[0035] In a further embodiment of the present invention, the cyclic execution of data acquisition, parameter comparison, and state adjustment process to achieve continuous closed-loop temperature control of powder bed heating includes: after a single heating state adjustment is completed, the full-domain data acquisition operation is restarted again at fixed sampling intervals;

[0036] The newly collected data will be used to re-divide the field, compensate for parameters, compare parameters, and generate instructions.

[0037] The entire process runs continuously and repeatedly, offsetting temperature fluctuations caused by powder heat dissipation, laser thermal interference, and powder spreading mechanical disturbances in real time, thus maintaining a stable temperature throughout the powder bed.

[0038] In a further embodiment of the present invention, the secondary parameter correction of the temperature control field located at the edge of the powder bed based on the heat transfer influence of adjacent fields includes: statistically analyzing the real-time temperature difference between the edge temperature control field and the adjacent inner field, and determining the heat loss ratio in combination with the heat conduction rate between fields.

[0039] A fixed compensation coefficient is added based on the proportion of heat loss and then added to the pre-compensated heating power.

[0040] For the temperature control field at the four corners of the powder bed, additional corner loss compensation is added to complete the secondary parameter correction of the edge field.

[0041] In a further embodiment of the present invention, the heating subunit corresponding to the edge region of the powder bed adopts a periodic pulse output mode for intermittent heating, including: setting the pulse working cycle and pulse duty cycle, outputting rated heating power during the high-level phase of the pulse, and maintaining a low-power standby state during the low-level phase of the pulse;

[0042] The pulse duty cycle is dynamically adjusted based on the real-time temperature of the edge field; the duty cycle is increased when the temperature is low and decreased when the temperature is high.

[0043] The pulse start and stop phases of all edge heating sub-units are staggered to avoid periodic overall temperature oscillations across the entire area.

[0044] The beneficial effects of this invention are:

[0045] This invention integrates three types of information—global powder temperature data, powder packing morphology data, and environmental heat transfer data—to form comprehensive monitoring data, constructing a multi-dimensional collaborative sensing system that no longer relies solely on temperature signals for regulation. By identifying differences in thermal resistance caused by local powder density and thickness, and combining this with protective gas flow rate and environmental radiative heat transfer coefficient to quantify heat loss, it can predict temperature change trends in different regions in advance, reducing coupling interference caused by powder morphology and environmental heat transfer at the source. This effectively reduces the difference between the heating rate and steady-state temperature at various points in the powder bed, significantly improving the global temperature consistency under conditions of large-size powder beds and high-melting-point powders, and reducing molding defects such as part warping and interlayer separation caused by temperature unevenness.

[0046] This invention divides the powder bed into independent temperature control fields with seamless connections of equal area, eliminating the temperature control blind spots present in traditional block partitions, and achieving precise temperature control of the entire powder bed without dead angles; for the different heat dissipation characteristics of the powder center, edge, and corner, constant heating and pulse intermittent heating modes are adopted respectively, and graded heat compensation is performed on the edge and corner areas to accurately match the heat loss patterns at different locations. Attached Figure Description

[0047] Figure 1 This is a schematic diagram of the steps of the method of the present invention. Detailed Implementation

[0048] The technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.

[0049] In the description of this application, it should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. For ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following drawings denote similar items; therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.

[0050] It should be noted that the terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class, without limiting the number of objects; for example, the first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0051] It should be noted that in the description of this application, the directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this application. The directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0052] It should be noted that, in this application, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. Furthermore, it should be noted that the scope of the methods and apparatuses in the embodiments of this application is not limited to performing functions in the order shown or discussed, but may also include performing functions substantially simultaneously or in the reverse order, depending on the functions involved. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.

[0053] This embodiment provides a powder global heating temperature control method for powder laser sintering 3D printing equipment, including the following steps: collecting temperature data, powder accumulation morphology data and environmental heat transfer data within the entire range of the powder bed, and integrating them to obtain comprehensive monitoring data; unlike the conventional method of collecting only the powder surface temperature in the existing technology, a three-source heterogeneous data collaborative acquisition mode of temperature, powder morphology and environmental heat transfer is adopted, and temperature is no longer used as the only control basis.

[0054] By linking multi-dimensional data, the internal thermal resistance distribution of the powder bed and external heat loss, among other influencing factors, can be comprehensively characterized. This addresses the shortcomings of traditional solutions, which rely on single monitoring dimensions and cannot predict temperature deviations, providing complete data support for subsequent precise temperature control and effectively improving the predictive capability and accuracy of overall temperature regulation. Based on the spatial distribution characteristics of the powder bed, several seamlessly connected independent temperature control areas are defined, and the basic heating parameters of each temperature control area are matched with the sintering process parameters. This step abandons the industry-standard block-like, coarse zoning method and adopts a seamless, equal-area, full-domain field division logic, completely eliminating the blind spots and temperature control dead zones present in traditional zoning, truly achieving 100% full coverage of the powder bed. Simultaneously, the basic heating parameters are matched with the entire laser sintering process parameters, ensuring a deep fit between the initial heating parameters and the actual forming conditions. From the perspective of field planning and parameter initialization, this solves the problem of localized temperature runaway caused by unreasonable zoning and the disconnect between basic parameters and the process, thus building a basic framework for refined zoned temperature control.

[0055] By utilizing the thermal response characteristics of powder, pre-compensation calculations are performed on the basic heating parameters to obtain the real-time heating parameters for each temperature-controlled area. This step incorporates the inherent thermal hysteresis characteristics of the powder and the heat transfer characteristics of the environment into the feedforward pre-compensation calculation. The thermal response delay is quantified by combining the physical properties of the powder itself, and the heating parameters are corrected in advance before the heating action is executed. This fundamentally offsets the temperature regulation lag problem caused by the thermal inertia of the powder, significantly shortening the temperature response delay compared to traditional feedback temperature control and avoiding temperature deviation caused by temperature regulation lag. Simultaneously, secondary thermal correction is performed for the edge areas to further adapt to the heat dissipation patterns of different locations. Distributed heating components are driven to synchronously heat the entire powder bed according to the real-time heating parameters. Based on the refined real-time heating parameters calculated above, a zoned differentiated heating strategy is adopted, matching the corresponding heating output mode to different heat dissipation conditions at the center and edge of the powder bed, with the heating components working in a unified and coordinated sequence across the entire area. This method breaks away from the single mode of uniform heating across the entire area in existing technologies, specifically adapting to the differentiated scenarios of steady-state heat dissipation in the central area and rapid heat dissipation in the edge area, achieving precise on-demand heat input and effectively reducing the temperature difference between the center and edge of the powder bed. The system continuously collects real-time temperature data across the entire heating process and compares this data with preset multi-level temperature control thresholds. It abandons the single-threshold judgment logic of existing technologies and constructs a three-level linkage threshold system for low-temperature compensation, standard constant temperature, and high-temperature early warning, making independent temperature judgments for each independent temperature control field. By using multi-level thresholds to identify the degree of temperature deviation, it distinguishes between three operating conditions: normal range, low-temperature range, and high-temperature range, providing accurate judgment criteria for subsequent graded adjustments and solving the problems of coarse adjustment and inability to finely control temperature fluctuations in traditional single-threshold judgment methods. Based on the comparison results, it generates independent adjustment commands for each field, dynamically adjusting the heating status of each temperature control field. Combining the judgment results of multi-level thresholds, it adopts three differentiated adjustment logics: step-wise power increase, gradient power decrease, and parameter maintenance, generating and executing exclusive adjustment commands for each independent temperature control field. This achieves fine-grained dynamic temperature control with a "one field, one strategy" approach. Compared to a uniform overall temperature control method, it can individually correct local temperature anomalies, preventing local deviations from spreading to the entire field and further enhancing the uniformity of the overall temperature field.

[0056] The system continuously executes data acquisition, parameter comparison, and status adjustment processes to achieve continuous closed-loop temperature control for the entire powder bed heating domain. All these processes are continuously cyclically run to form a complete closed-loop control chain, responding in real-time to dynamic interference factors such as powder heat dissipation changes, instantaneous thermal shock from lasers, and mechanical disturbances from the powder spreading mechanism. By continuously correcting the temperature control parameters through closed-loop iteration, the entire temperature control system possesses adaptive anti-interference capabilities, solving the problem of existing temperature control systems being independent of the molding process and susceptible to temperature field instability due to external disturbances, thus maintaining long-term stable temperature across the entire powder bed domain.

[0057] Specifically, the temperature data, powder deposition morphology data, and environmental heat transfer data collected over the entire powder bed area are integrated to obtain comprehensive monitoring data covering the entire area, including:

[0058] A three-dimensional sensor array is deployed in the horizontal and vertical directions of the powder bed to collect temperature values ​​at multiple points in the powder surface, middle layer, and bottom layer, forming a global temperature dataset. In practice, the three-dimensional sensor array consists of high-temperature resistant miniature temperature sensors, densely arranged in a matrix along the horizontal, vertical, and thickness directions of the powder bed. The sensors are completely embedded within the powder deposition layer, rather than just being placed on the powder surface. For typical powder thickness ranges, sensors are deployed in layers at equal intervals in the vertical direction, corresponding to the powder surface layer, the intermediate transition layer, and the bottom bonding forming platform layer. Real-time temperature is collected at dozens of points in each layer, completely reconstructing the three-dimensional temperature distribution of the powder bed. This overcomes the limitation of existing technologies that only collect surface temperature and cannot obtain the internal temperature of the powder, ensuring that the temperature data accurately reflects the actual heating conditions of powder at different depths. A visual acquisition device scans the powder bed surface to identify local powder deposition thickness and particle density, obtaining a powder deposition morphology dataset. In practice, a high-precision industrial vision camera combined with a structured light scanning module is used to perform a global surface scan of the powder bed after powder deposition. This process utilizes image analysis algorithms to extract morphological features such as local powder deposition thickness, particle density, and local powder deficiency / accumulation, quantifying the powder deposition porosity in different regions. Powder density and thickness directly determine the magnitude of local thermal conductivity resistance. This step transforms powder morphological features into quantifiable thermal resistance reference data, overcoming the limitation of traditional temperature control completely ignoring the influence of powder morphology. It allows temperature control logic to be integrated with the actual powder deposition state, improving the completeness of data dimensions. The process also collects data on the protective gas flow rate, cavity wall temperature, and environmental radiative heat transfer coefficient within the printing cavity to obtain an environmental heat transfer dataset. Specifically, gas flow rate sensors, contact temperature sensors, and radiative heat transfer detection modules are deployed at multiple points inside the printing cavity to comprehensively collect the inert protective gas flow rate, flow direction, real-time cavity wall temperature, and overall radiative heat transfer coefficient within the cavity. During SLS printing, the continuous flow of protective gas constantly carries away heat from the powder surface, and thermal radiation from the cavity wall also exchanges heat with the powder. This step fully captures these external heat transfer parameters, quantifying the interference of the external environment on powder temperature, and overcoming the shortcomings of existing technologies that do not consider cavity environmental heat transfer and whose parameter settings are detached from actual working conditions. The global temperature dataset, powder deposition morphology dataset, and environmental heat transfer dataset are aligned along their timelines and fused into a comprehensive global monitoring dataset. In practice, a time-series synchronization module unifies the acquisition timestamps of the three types of data, ensuring a one-to-one correspondence between temperature, morphology, and environmental data collected at the same time. A data fusion algorithm then structurally encapsulates the multi-source data, forming comprehensive global monitoring data with spatial location identifiers, temporal identifiers, and multi-dimensional attributes. Unified time series avoids analytical biases caused by asynchronous data acquisition. The structured and encapsulated data can be directly accessed by the backend computation module, providing uniformly formatted and logically connected raw data for subsequent field division and parameter calculation, ensuring the stability of the entire method's data flow.By using a multi-source data fusion scheme that integrates three-dimensional temperature measurement, powder morphology scanning, and cavity environment parameter acquisition, the system comprehensively covers three major influencing factors: powder internal state, powder morphology, and external heat exchange. The monitoring dimensions are far more than those of traditional single temperature measurement schemes, enabling early identification of potential temperature deviation risks and improving the predictability and comprehensiveness of the temperature control system from the sensing end.

[0059] Specifically, the process involves dividing the powder bed into several seamlessly connected independent temperature-controlled fields based on its spatial distribution characteristics, and matching the basic heating parameters of each temperature-controlled field with the sintering process parameters, including:

[0060] The entire powder bed is divided into multiple independent temperature-controlled zones using equal-area units. There are no blank areas between adjacent temperature-controlled zones, and their boundaries are tightly fitted. In practice, the powder bed is divided equally according to fixed unit areas based on its overall length and width. All temperature-controlled zones have identical shapes and areas, and their boundaries are tightly fitted, with no undefined or overlapping areas. Unlike existing technologies that passively divide zones based on sintering contours and temperature anomaly areas, this solution actively performs a global grid-based equal division of the entire powder bed. This ensures that each powder area corresponds to a dedicated temperature-controlled unit, completely eliminating temperature control blind spots in traditional partitioning methods. It truly achieves "global, no-dead-angle" temperature control, adapting to molding conditions with any sintering contour, and offering greater versatility. The laser sintering power, single-layer powder thickness, scanning speed, and single sintering time are read as sintering process parameters. In practice, the process commands issued by the 3D printer are read in real-time through the device communication interface, simultaneously acquiring four core process parameters: rated laser output power, powder thickness of each layer, laser scanning speed, and the time required for complete sintering of a single layer. Laser energy, powder thickness, and scanning speed directly alter the powder's heating baseline and heat load. This step is linked to the core forming process in real-time, deeply binding the basic parameters of the temperature control field with the current printing conditions, avoiding the problem of fixed basic heating parameters failing to adapt to dynamic process changes. Combining the sintering temperature range and thermal conductivity of the powder to be processed, basic heating power, basic heating time, and basic thermal radiation angle are configured for each independent temperature control field, determining the corresponding basic heating parameters for each field. In practice, the material property database of the currently used powder is retrieved to obtain the minimum sintering temperature and maximum withstand temperature of the powder, constituting the sintering temperature range, while simultaneously acquiring the thermal conductivity of the powder itself. For each gridded temperature control area, three basic parameters are independently configured based on the area's location, powder properties, and sintering process: basic heating power determines the heat output per unit time, basic heating duration determines the duration of continuous heating in a single cycle, and basic thermal radiation angle determines the heat radiation coverage area. Compared to existing technologies that uniformly configure basic parameters across the entire area, this solution enables independent configuration of parameters for each area, allowing basic heating parameters to accurately match the powder and operating conditions of the corresponding region, reducing temperature unevenness from the outset. Seamless and uniform gridded area division achieves full coverage of the powder bed, eliminating temperature control dead zones; process parameters, powder material parameters, and basic area parameters are linked and matched, giving the initial heating parameters strong adaptability to operating conditions, laying a solid foundation for subsequent precise temperature control.

[0061] Specifically, the pre-compensation calculation of basic heating parameters using the thermal response characteristics of powder to obtain real-time heating parameters for each temperature-controlled field includes:

[0062] The thermal hysteresis coefficient λ of the powder in a single field is calculated based on the powder particle size and packing porosity. Combined with the environmental heat transfer coefficient α and the basic heating power P0 of the field, the following formula is used: The pre-compensated heating power P is calculated, where λ is the difference between the measured temperature of the field and the theoretical reference temperature. In specific implementation, the average particle size and local packing porosity of the powder are extracted based on the previously collected powder morphology data, and substituted into the thermal hysteresis calculation model to obtain the thermal hysteresis coefficient λ, which characterizes the degree of powder thermal response delay. The environmental heat transfer coefficient α in the environmental heat transfer dataset is retrieved, and combined with the initial configuration of the field's basic heating power P0 and the difference between the measured temperature and the theoretical reference temperature λ, it is substituted into a dedicated coupled calculation formula to complete the calculation. This calculation formula is customized for SLS powder heating scenarios, coupling the calculation of three types of factors: powder microstructure, environmental heat transfer properties, and temperature deviation. This differs from the traditional temperature control logic, which only relies on the temperature difference for simple correction. Power pre-compensation is completed before the heating action is executed, which falls under the category of feedforward control. It offsets the power deviation caused by powder thermal hysteresis and environmental heat dissipation in advance, completely changing the passive control mode of the existing technology of "heating first, then measuring temperature, and then correcting". It solves the problem of temperature hysteresis caused by powder thermal inertia from the control logic. Based on the influence of heat transfer between adjacent fields, a secondary parameter correction is performed on the temperature control field located at the edge of the powder bed, ultimately outputting the real-time heating parameters for all temperature control fields. In practice, natural heat conduction and heat exchange occur between adjacent fields within the powder bed. Besides conventional heat dissipation, the edge fields also lose a significant amount of heat to the equipment cavity, resulting in heat loss far exceeding that of the internal fields. Therefore, after completing the formula pre-compensation, an additional secondary parameter correction is performed for the edge fields. Taking into account both the heat input from adjacent inner fields and the heat outflow from the cavity environment, a secondary fine-tuning of the heating power is made to balance the parameter deviations caused by heat transfer between fields and external heat dissipation. Finally, the real-time heating parameters for all fields are output after double correction. This step, which adds inter-field heat transfer correction to the general pre-compensation, further improves the parameter accuracy in the edge region, and is a key innovation of this invention that distinguishes it from general feedforward compensation technology. A proprietary coupling formula is used to achieve feedforward pre-compensation based on powder thermal hysteresis and environmental heat exchange, which corrects the heating power in advance and overcomes the temperature adjustment delay caused by powder thermal inertia. Secondary parameter correction is added for the edge field to adapt to the heat transfer between fields and the high heat dissipation characteristics at the edge. The calculation accuracy of heating parameters and the adaptability of working conditions are greatly improved, and the temperature control response speed is significantly better than the traditional feedback temperature control scheme.

[0063] Specifically, the step of driving the distributed heating components to synchronously perform heating operations across the entire powder bed according to real-time heating parameters includes:

[0064] The real-time heating parameters corresponding to each temperature-controlled field are distributed one-to-one to each heating subunit within the distributed heating assembly. In practice, the distributed heating assembly consists of independent heating subunits that correspond one-to-one with the number and location of the temperature-controlled fields. Each heating subunit physically corresponds to a gridded temperature-controlled field and has independent power adjustment and start-stop control capabilities. The main control module distributes the calculated real-time heating parameters point-to-point to the corresponding heating subunit according to the field number, achieving precise matching of "one field, one heating unit, one set of dedicated parameters," eliminating parameter mismatches and the problem of shared parameters across the entire field, and ensuring that each powder area is heated according to customized parameters. The heating subunit corresponding to the central area of ​​the powder bed continuously heats the powder bed using a constant output mode, while the heating subunit corresponding to the edge area uses a periodic pulse output mode for intermittent heating. In practice, the area is divided into central and edge groups based on its location, and these two groups employ differentiated operating modes: the central area, surrounded by powder, experiences slow heat loss and a stable heat dissipation environment; therefore, its heating subunit uses a constant power continuous output mode to maintain a stable temperature. The edge area, directly in contact with the cavity air and walls, experiences rapid heat loss and large heat dissipation fluctuations; constant heating in this area would easily result in low temperatures or wasted power. Therefore, a periodic pulse intermittent heating mode is used, dynamically matching the dynamic heat dissipation patterns of the edge area through pulses. This differentiated heating mode is a customized design for the heat dissipation characteristics of different locations on the powder bed, completely different from the conventional solution of uniform heating across the entire area in existing technologies. All heating subunits maintain a unified operating sequence, ensuring synchronized heat input across the entire powder bed. Specifically, the main control module outputs a unified timing signal to maintain consistent start-up points and operating cycles for all heating subunits, preventing localized instantaneous high temperatures and heat shortages caused by asynchronous start-up and shutdown of different heating units. Synchronized heat input across the entire area ensures a consistent overall temperature rise trend for the powder bed, further guaranteeing temperature uniformity from a heating execution perspective. Precise matching between heating units and temperature control areas ensures error-free parameter distribution. A differentiated heating mode—constant central heating plus edge pulse heating—precisely adapts to the heat dissipation characteristics of different areas, balancing temperature control effectiveness and energy consumption. A unified operating sequence across the entire area prevents localized temperature anomalies caused by asynchronous heating, resulting in more balanced heat input across the entire area.

[0065] Specifically, the continuous acquisition of real-time temperature data across the entire heating process, and the comparison of the real-time temperature data with a preset multi-level temperature control threshold group, includes:

[0066] A multi-level temperature control threshold group is constructed by pre-setting a low-temperature compensation threshold, a standard constant temperature threshold, and a high-temperature warning threshold. In practice, based on the current powder sintering process requirements, three gradient temperature threshold ranges are manually defined: below the low-temperature compensation threshold is considered an insufficient temperature range; between the low-temperature compensation threshold and the high-temperature warning threshold is considered a standard constant temperature range; and above the high-temperature warning threshold is considered a temperature exceeding the limit range. This three-level linkage multi-level threshold group replaces the existing single critical threshold method, enabling stratified definition of temperature states. It can distinguish between different operating conditions such as slightly low temperature, normal temperature, slightly high temperature, and severe over-temperature, providing a basis for graded adjustment and improving the precision of temperature state identification. The real-time temperature of each independent temperature control field is extracted one by one, and the temperature value of a single field is compared with each threshold in the multi-level temperature control threshold group. In practice, during the heating process, the real-time temperature of each gridded temperature control field is continuously read at a fixed sampling frequency. The temperature of each field is independently compared with the three-level threshold values ​​to determine the current temperature range of that field. Adhering to the principle of "independent judgment for each field," the system avoids using the overall average temperature for judgment, preventing local temperature anomalies from being masked by the overall average and ensuring that every minute temperature deviation can be accurately identified. The judgment results for each temperature control field, along with the magnitude of temperature deviation from the threshold, are recorded to form a global temperature judgment result set. In practice, the judgment conclusion for each field, the difference between the actual temperature and the corresponding threshold, are recorded item by item, sorted and summarized according to the field's spatial location, forming a structured global temperature judgment result set. The result set completely retains three key pieces of information: the location, direction, and magnitude of the temperature deviation. This provides complete and traceable original judgment data for the backend to generate differentiated adjustment commands, ensuring that adjustment actions accurately correspond to the temperature anomaly points. Multi-level threshold groups enable layered judgment of temperature states, achieving a recognition accuracy far exceeding that of traditional single-threshold schemes. Independent judgment for each field, combined with deviation magnitude recording, accurately captures minute local temperature anomalies, preventing the omission of local defects due to global averaging, making temperature anomaly identification more comprehensive and refined.

[0067] Specifically, the step of generating independent field adjustment commands based on the comparison results to dynamically adjust the heating state of each temperature-controlled field includes:

[0068] When the real-time temperature of the temperature-controlled area is below the low-temperature compensation threshold, a stepped power increase command is generated. In practice, multiple increase levels are defined based on the deviation of the temperature from the threshold; the smaller the deviation, the smaller the power increase; the larger the deviation, the larger the power increase. This step-by-step increase in heating power, rather than a one-time full-scale increase, avoids drastic temperature fluctuations caused by sudden power increases, ensuring stable heating in low-temperature areas. When the real-time temperature of the temperature-controlled area is above the high-temperature warning threshold, a gradient power decrease command is generated. In practice, for overheated areas, multiple decrease levels are defined based on the degree of overheating; the more severe the overheating, the larger the power decrease. This gradient reduction in heating power prevents a sudden drop in power that could cause a precipitous temperature drop, ensuring stable cooling in high-temperature areas. When the real-time temperature of the temperature-controlled area is within the standard constant temperature threshold range, the current heating parameters remain unchanged. In practice, for areas with temperatures within the acceptable range, the existing heating power and operating mode are locked without any adjustments, avoiding ineffective adjustments that could introduce new temperature disturbances and maintaining temperature stability in the steady-state region. All field adjustment commands are sorted and integrated according to spatial location to generate complete field-independent adjustment commands, and the operating parameters of the corresponding heating sub-units are changed according to the commands. In specific implementation, all field adjustment, down adjustment, and maintenance commands are summarized and encapsulated according to spatial location to form a global command set, which is then sent point-to-point to the corresponding heating sub-units. Each heating sub-unit only executes the adjustment command corresponding to its own field. This achieves fine-grained dynamic adjustment that corrects local anomalies locally and maintains overall steady state globally, unlike the crude mode of synchronous temperature adjustment across the entire field in existing technologies. It will not change the overall heating state due to local temperature anomalies. The stepped and gradient power adjustment method achieves smooth temperature rise and fall, eliminating temperature oscillations caused by sudden power changes. Field-independent command adjustment achieves "precise correction of abnormal points and no interference in normal areas," and local temperature deviations will not spread to the entire field, further enhancing the stability of the global temperature field of the powder bed.

[0069] Specifically, the cyclic execution of data acquisition, parameter comparison, and state adjustment processes to achieve continuous closed-loop temperature control for the entire heating range of the powder bed includes:

[0070] After a single heating state adjustment is completed, the full-domain data acquisition operation is restarted at a fixed sampling interval. In practice, after completing one round of heating parameter adjustment, the system waits for a preset fixed sampling interval to avoid data distortion caused by overlapping adjustment and data acquisition actions. After the interval ends, the multi-source data acquisition of full-domain temperature, powder morphology, and environmental heat transfer is immediately restarted to ensure the continuity and timeliness of data acquisition. The newly acquired data is then used to re-compile the field, perform parameter compensation, parameter comparison, and command generation operations. In practice, the newly acquired comprehensive monitoring data will completely reproduce all the previous calculation processes: field state verification, thermal hysteresis and heat transfer coefficient pre-compensation calculation, multi-level threshold comparison, and adjustment command generation. The entire set of calculation logic runs continuously in a loop, allowing the system to continuously adapt to the dynamic changes in powder state, environmental conditions, and molding process. This invention operates continuously and iteratively throughout the entire process, effectively mitigating temperature fluctuations caused by powder heat dissipation, laser thermal interference, and mechanical disturbances during powder spreading, thus maintaining a stable temperature across the entire powder bed. In practice, the laser scanning and sintering process generates instantaneous additional heat, the movement of the powder spreading mechanism causes mechanical disturbances and localized powder displacement, and changes in airflow within the cavity alter the heat dissipation rate. These dynamic disturbances are a major challenge for existing temperature control systems. This invention relies on a continuous closed-loop cycle to sense temperature changes caused by disturbances in real time and quickly correct parameters, actively mitigating the effects of various dynamic disturbances and ensuring long-term stability of the powder bed temperature field even under complex dynamic conditions. The continuous closed-loop iteration throughout the entire process provides the system with dynamic adaptive capabilities, enabling it to mitigate external disturbances such as laser thermal shock, powder spreading disturbances, and airflow changes in real time. This solves the problems of weak anti-interference capabilities and easy temperature instability after changes in operating conditions in traditional temperature control systems, ensuring that the temperature remains within the acceptable range throughout long-term continuous printing.

[0071] Specifically, the secondary parameter correction of the temperature control field located at the edge of the powder bed, based on the heat transfer influence of adjacent fields, includes:

[0072] The real-time temperature difference between the edge temperature control area and the adjacent inner area is statistically analyzed, and the heat loss ratio is determined by combining the heat conduction rate between the areas. In practice, real-time temperature data of the edge area and the directly adjacent inner area are retrieved, the temperature difference between the two is calculated, and the inherent heat conduction rate of the powder layer is combined to quantify the heat transfer from the inner area to the edge area and the heat loss from the edge area to the cavity, ultimately obtaining the overall heat loss ratio of the edge area. By replacing traditional empirical parameter compensation with quantitative calculation, the basis for correction changes from manual experience to measured data and heat conduction laws, significantly improving the accuracy of correction. A fixed compensation coefficient is added based on the heat loss ratio and superimposed on the pre-compensated heating power. In practice, the corresponding compensation coefficient is matched according to the calculated heat loss ratio, and the compensation coefficient is superimposed on the pre-compensated heating power to compensate for the power loss caused by heat transfer between areas and heat dissipation from the cavity, ensuring that the effective heating power of the edge area matches the actual heat loss level. For the temperature control areas at the four corners of the powder bed, additional corner loss compensation is added to complete the secondary parameter correction of the edge area. In specific implementation, the four corners of the powder bed are multiple heat dissipation superposition areas, with heat dissipation from the sides in two directions plus heat dissipation from the top surface, resulting in a heat loss rate much higher than that of ordinary edge areas. Therefore, based on the compensation of ordinary edge areas, an additional dedicated corner loss compensation is added to the corner areas, distinguishing between ordinary edges and corner edges as two types of high-loss areas, and performing graded differentiated compensation to ultimately complete the secondary parameter correction of all edge areas. This graded compensation logic is a refined design never used in existing technologies, specifically addressing the persistent problem of low temperature in corner areas. Based on temperature difference and heat conduction rate quantification of heat loss, the compensation method has shifted from empirical to data-driven, resulting in higher accuracy; the graded compensation distinguishes between ordinary edges and corner edges, adapting to the multiple heat dissipation characteristics of different locations, and completely solving the industry pain point of insufficient temperature at the corners and edges of powder beds.

[0073] Specifically, the heating subunit corresponding to the edge region of the powder bed adopts a periodic pulse output mode for intermittent heating, including:

[0074] The pulse working cycle and pulse duty cycle are set. During the high-level phase of the pulse, the rated heating power is output, and during the low-level phase, a low-power standby state is maintained. In specific implementation, the complete pulse working cycle and the time ratio of high and low levels within the cycle (duty cycle) are pre-configured. During the high-level phase, the heating subunit outputs rated power to achieve efficient heating, and during the low-level phase, it switches to low-power standby mode to maintain only the base temperature and avoid a temperature drop caused by complete heating stoppage. The parameters of the pulse working mode can be flexibly configured according to the powder material and cavity environment to adapt to the edge heat dissipation rhythm under different operating conditions. The pulse duty cycle is dynamically adjusted according to the real-time temperature of the edge field. When the temperature is low, the duty cycle is increased; when the temperature is high, the duty cycle is decreased. In specific implementation, the pulse duty cycle is dynamically adjusted based on the real-time temperature status of the edge field obtained by multi-level threshold comparison: when the temperature is low, the high-level heating duration is extended and the duty cycle is increased to improve the overall heat output; when the temperature is high, the high-level duration is shortened and the duty cycle is decreased to reduce the overall heat output. This achieves linkage between pulse parameters and real-time temperature changes, giving the pulse heating mode dynamic adaptive capability. The pulse start and stop phases of all edge heating subunits are staggered to avoid periodic overall temperature oscillations across the entire area. In practice, the pulse start times of each edge heating subunit are staggered, with high and low level phases alternating between different units, rather than all edge units starting and stopping synchronously. Synchronous pulses would cause periodic fluctuations in the overall heat of the powder bed, leading to overall temperature oscillations. The phase staggered design disperses pulse fluctuations, confining local heat fluctuations to a single field area, effectively suppressing overall periodic temperature oscillations. The pulse high and low level partitioning balances heating efficiency and temperature stability; dynamic duty cycle adjustment adapts the pulse mode to real-time temperature changes in the edge area; and the pulse phase staggered design eliminates overall periodic temperature oscillations from the operational mechanism, further improving the dynamic stability of the powder bed temperature field.

[0075] The embodiments of this application have been described above with reference to the accompanying drawings. Unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other. This application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this application.

Claims

1. A method for temperature control of powder global heating in powder laser sintering 3D printing equipment, characterized in that, Includes the following steps: Temperature data, powder deposition morphology data, and environmental heat transfer data are collected throughout the powder bed area and integrated to obtain comprehensive monitoring data for the entire area. Based on the spatial distribution characteristics of the powder bed, several seamlessly connected independent temperature control fields are divided, and the basic heating parameters of each temperature control field are matched in combination with the sintering process parameters. By utilizing the thermal response characteristics of powder, the basic heating parameters are pre-compensated and calculated to obtain the real-time heating parameters of each temperature control field. The distributed heating components are driven to synchronously heat the entire powder bed according to real-time heating parameters. Continuously collect real-time temperature data across the entire heating process and compare the real-time temperature data with a preset multi-level temperature control threshold group; Based on the comparison results, independent adjustment commands are generated for each temperature-controlled field to dynamically adjust the heating status of each field. The process of data acquisition, parameter comparison, and status adjustment is executed in a loop to achieve continuous closed-loop temperature control for the entire heating range of the powder bed.

2. The powder laser sintering 3D printing equipment powder global heating temperature control method according to claim 1, characterized in that, The temperature data, powder accumulation morphology data and environmental heat transfer data collected throughout the powder bed are integrated to obtain comprehensive monitoring data, including: deploying a three-dimensional sensor array in the horizontal and vertical thickness directions of the powder bed to collect multiple temperature values ​​of the powder surface, middle layer and bottom layer to form a comprehensive temperature dataset. By scanning the powder bed surface with a visual acquisition device, the local powder accumulation thickness and particle density are identified, and a powder accumulation morphology dataset is obtained. Collect the protective gas flow rate, cavity wall temperature, and ambient radiative heat transfer coefficient inside the printing cavity to obtain an ambient heat transfer dataset; The global temperature dataset, powder accumulation morphology dataset, and environmental heat transfer dataset are aligned along the time axis and then merged and packaged into a comprehensive global monitoring dataset.

3. The powder laser sintering 3D printing equipment powder global heating temperature control method according to claim 1, characterized in that, The process involves dividing the powder bed into several seamless independent temperature control fields based on its spatial distribution characteristics, and matching the basic heating parameters of each temperature control field with the sintering process parameters. This includes dividing the entire powder bed into multiple independent temperature control fields in the form of equal area units, with no blank areas between adjacent temperature control fields and their boundaries fitting together. The laser sintering power, single-layer powder thickness, scanning travel speed, and single sintering time are read as sintering process parameters. Based on the sintering temperature range and thermal conductivity of the powder to be processed, the basic heating power, basic heating time, and basic thermal radiation angle are configured for each independent temperature control field, and the basic heating parameters corresponding to each field are determined.

4. The powder laser sintering 3D printing equipment powder global heating temperature control method according to claim 1, characterized in that, The process involves pre-compensating the basic heating parameters using the thermal response characteristics of powder to obtain the real-time heating parameters for each temperature-controlled field. This includes: calculating the thermal hysteresis coefficient λ of the powder in a single field based on the powder particle size and packing porosity; combining this with the environmental heat transfer coefficient α and the basic heating power P0 of the field; and then applying the formula: The pre-compensated heating power P is calculated, where λ is the difference between the measured temperature of the field and the theoretical reference temperature. Based on the influence of heat transfer between adjacent fields, secondary parameter correction is performed on the temperature control field located at the edge of the powder bed, and finally the real-time heating parameters of all temperature control fields are output.

5. The powder laser sintering 3D printing equipment powder global heating temperature control method according to claim 1, characterized in that, The method of driving the distributed heating components to synchronously heat the entire powder bed according to real-time heating parameters includes: The real-time heating parameters corresponding to each temperature control field are sent one by one to each heating subunit in the distributed heating component; The heating subunit corresponding to the central area of ​​the powder bed adopts a constant output mode for continuous heating, while the heating subunit corresponding to the edge area of ​​the powder bed adopts a periodic pulse output mode for intermittent heating. All heating subunits maintain a unified operating sequence, ensuring that the heat input rhythm across the entire powder bed remains synchronized.

6. The powder laser sintering 3D printing equipment powder global heating temperature control method according to claim 1, characterized in that, The continuous acquisition of real-time temperature data across the entire heating process compares the real-time temperature data with a preset multi-level temperature control threshold group, including: a preset low-temperature compensation threshold, a standard constant temperature threshold, and a high-temperature warning threshold, which together constitute a multi-level temperature control threshold group. The real-time temperature of each independent temperature-controlled field is extracted one by one, and the temperature value of a single field is compared with the threshold values ​​in the multi-level temperature control threshold group to determine the magnitude of the temperature value. Record the judgment results for each temperature control field and the magnitude of temperature deviation from the threshold to form a global temperature judgment result set.

7. The powder laser sintering 3D printing equipment powder global heating temperature control method according to claim 6, characterized in that, The process of generating independent adjustment commands for each temperature-controlled field based on the comparison results and dynamically adjusting the heating status of each temperature-controlled field includes: generating a step-wise power increase command when the real-time temperature of the temperature-controlled field is lower than the low-temperature compensation threshold. When the real-time temperature of the temperature-controlled field exceeds the high-temperature warning threshold, a gradient power reduction command is generated. When the real-time temperature of the temperature control field is within the standard constant temperature threshold range, the current heating parameters remain unchanged; All field adjustment commands are sorted and integrated according to spatial location to generate complete field-independent adjustment commands, and the operating parameters of the corresponding heating sub-units are changed according to the commands.

8. The powder laser sintering 3D printing equipment powder global heating temperature control method according to claim 1, characterized in that, The described process of cyclically executing data acquisition, parameter comparison, and status adjustment enables continuous closed-loop temperature control of the powder bed's full-area heating, including: after a single heating status adjustment is completed, the full-area data acquisition operation is restarted again at fixed sampling intervals; The newly collected data will be used to re-divide the field, compensate for parameters, compare parameters, and generate instructions. The entire process runs continuously and repeatedly, offsetting temperature fluctuations caused by powder heat dissipation, laser thermal interference, and powder spreading mechanical disturbances in real time, thus maintaining a stable temperature throughout the powder bed.

9. The powder laser sintering 3D printing equipment powder global heating temperature control method according to claim 4, characterized in that, The method of performing secondary parameter correction on the temperature control field located at the edge of the powder bed based on the heat transfer influence of adjacent fields includes: statistically analyzing the real-time temperature difference between the edge temperature control field and the adjacent inner field, and determining the heat loss ratio by combining the heat conduction rate between fields. A fixed compensation coefficient is added based on the proportion of heat loss and then added to the pre-compensated heating power. For the temperature control field at the four corners of the powder bed, additional corner loss compensation is added to complete the secondary parameter correction of the edge field.

10. The powder laser sintering 3D printing equipment powder global heating temperature control method according to claim 5, characterized in that, The heating subunit corresponding to the edge area of ​​the powder bed adopts a periodic pulse output mode for intermittent heating, including: setting the pulse working period and pulse duty cycle, outputting rated heating power during the high-level pulse phase, and maintaining a low-power standby state during the low-level pulse phase; The pulse duty cycle is dynamically adjusted based on the real-time temperature of the edge field; the duty cycle is increased when the temperature is low and decreased when the temperature is high. The pulse start and stop phases of all edge heating sub-units are staggered to avoid periodic overall temperature oscillations across the entire area.

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