A method and system for controlling the heating process of an electromagnetic oven

Abstract

The application provides an electromagnetic oven heating process control method and system, relates to the technical field of electromagnetic ovens, and is combined with the real-time monitoring of the temperature rise rate of the electromagnetic oven panel temperature measurement point and the coil power distribution and leakage magnetic field distribution map under the eccentric placement of the pot, so as to accurately identify and locate the main coil causing the local overheating risk, and further periodically modulate the waveform amplitude of the pulse width modulation duty cycle of the main coil, so that the safety risk caused by the local leakage magnetic field is effectively inhibited without interrupting the cooking task, and the effect of maintaining the uniform heating is achieved. The cooking task failure and the decline of the user experience caused by the simple and rough interruption of the traditional safety mechanism are avoided, the balance between safety and cooking continuity is achieved, and the intelligence and user friendliness of the electromagnetic oven are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of induction cookers, in particular to an induction cooker heating process control method and system. BACKGROUND

[0002] As a widely used heating appliance in modern kitchens, induction cookers are favored for their efficient and precise temperature control capabilities. In the prior art, to solve the problem of uneven heating when the pot is not placed in the center, some induction cookers are configured with multiple independently controllable heating coils, and the power output of each coil is adjusted according to the actual position of the pot to achieve uniform heating of the off-center placed pot. This method improves the heating uniformity to some extent.

[0003] However, under certain operating conditions, such as long-time low-power cooking tasks that require maintaining a specific temperature, the power output of some coils will be significantly increased in order to enhance the heating effect on the edge area of the pot. This asymmetric energy output strategy can cause a concentrated leakage magnetic field in the empty area of the induction cooker panel outside the pot. When the user inadvertently places a metal utensil in this leakage magnetic field area, the metal utensil will be inductively heated, and its temperature may rise sharply to a dangerous level.

[0004] The safety protection mechanism of the existing induction cooker usually adopts the most conservative strategy when detecting a locally abnormally high temperature on the panel, that is, significantly reducing or stopping the power output of all coils to eliminate safety hazards. Although this can eliminate safety risks, it directly leads to the forced interruption of cooking tasks, seriously affecting user experience and cooking efficiency. More seriously, when the user repeatedly performs similar operations, the system may fall into an ineffective cycle of "normal heating - generating hazards - stopping heating - manual intervention - normal heating". The decision logic of such a control system shows fundamental defects when faced with the complex dilemma caused by its own pursuit of performance goals (such as heating uniformity) and the interaction with the user's unconscious normal behavior patterns. It lacks a method to understand and handle such target conflicts, and cannot effectively balance between the two goals of "ensuring cooking" and "ensuring safety", but instead switches between the two.

[0005] Therefore, it is an urgent problem for those skilled in the art to provide an induction cooker heating process control method and system to solve the above problems. SUMMARY

[0006] To solve the problems of the prior art, the present application provides an induction cooker heating process control method and system, which can intelligently identify and adjust the risk of overheating caused by local leakage magnetic field, avoiding the problem of interrupting cooking in traditional safety mechanisms, and improving user experience and safety.

[0007] To achieve the above object, the present application provides the following technical solutions:

[0008] The electromagnetic oven heating process control method is applied to a local leakage magnetic field scene, and includes the following steps:

[0009] In a first time period, a first actual temperature of all temperature measuring points of the electromagnetic oven panel is collected at a first frequency, an actual temperature rise rate of each temperature measuring point is calculated, and when the actual temperature rise rate of the first temperature measuring point meets a preset condition, the risk type of the electromagnetic oven is determined;

[0010] When the pot is placed away from the center, pot position information is obtained, the actual power distribution of the electromagnetic oven coil is obtained according to the pot position information, the first electromagnetic oven coil with the largest leakage magnetic field power output contribution to the first temperature measuring point is determined according to the actual power distribution of the electromagnetic oven coil and a leakage magnetic field distribution map of the electromagnetic oven panel;

[0011] According to the first adjustment strategy, the pulse width modulation duty cycle of the first electromagnetic oven coil is modulated at a first periodic waveform amplitude at a first adjustment frequency;

[0012] After the modulation is completed, a second actual temperature of the first temperature measuring point is collected at a second frequency, whether the second actual temperature of the first temperature measuring point meets a downward trend is judged, and the first judgment result is recorded, and if the first judgment result is yes, the first adjustment strategy is defined as effective.

[0013] Through the above scheme, the local leakage magnetic field caused overheating risk can be intelligently identified and targetedly adjusted, the problem that the traditional safety mechanism interrupts cooking is avoided, and the user experience and safety are improved.

[0014] Preferably, after the risk type of the first electromagnetic oven coil and the first temperature measuring point is determined, the following steps are further included:

[0015] According to the second adjustment strategy, the first power value of the first electromagnetic oven coil is periodically transferred to a second electromagnetic oven coil with a lower leakage magnetic field power output contribution within a second time period.

[0016] Through the above scheme, the local overheating risk is further reduced through power transfer, while the overall heating effect is maintained, and the safety and cooking continuity are enhanced.

[0017] Preferably, after whether the second actual temperature of the first temperature measuring point meets a downward trend is judged and the first judgment result is recorded, the following steps are included:

[0018] If the first judgment result is no, the first adjustment frequency is increased to a second adjustment frequency or the first periodic waveform amplitude is increased to a second periodic waveform amplitude;

[0019] According to the first adjustment strategy, the pulse width modulation duty cycle of the first electromagnetic oven coil is modulated with the first periodic waveform amplitude at the second adjustment frequency as the first adjustment scheme.

[0020] Or, according to the first adjustment strategy, the pulse width modulation duty cycle of the first electromagnetic oven coil is modulated with the second periodic waveform amplitude at the first adjustment frequency as the second adjustment scheme.

[0021] Or, when the first adjustment scheme or the second adjustment scheme is adopted, the second adjustment strategy is executed in parallel.

[0022] Through the above scheme, multiple adjustment schemes are provided, and when the initial adjustment strategy is not effective, the adjustment strength can be flexibly improved or combined with other strategies to ensure that the risk is effectively removed.

[0023] Preferably, in the first time period, the first actual temperature of all temperature measuring points of the electromagnetic oven panel is collected at the first frequency, the actual temperature rise rate of each temperature measuring point is calculated, and when the actual temperature rise rate of the first temperature measuring point meets the preset condition, the risk type of the electromagnetic oven is determined, including the following steps:

[0024] In the first preset period, the first actual temperature data of all temperature measuring points is collected according to the thermistor sensor and the digital converter of each temperature measuring point at the first frequency;

[0025] The actual temperature rise rate of each temperature measuring point is calculated according to the temperature rise rate formula and recorded as the second judgment result.

[0026] Judge whether the actual temperature rise rate of the first temperature measuring point is greater than the preset metal object induced temperature rise threshold value;

[0027] If the second judgment result is yes, it is defined that the electromagnetic oven has an external metal heating risk.

[0028] Through the above scheme, the determination process of the risk type is defined in detail, and the external metal heating risk can be accurately identified, which provides a basis for subsequent precise control.

[0029] Preferably, when the pot is placed off-center, the pot position information is obtained, the actual power distribution of the electromagnetic oven coil is obtained according to the pot position information, and the actual power distribution of the electromagnetic oven coil and the electromagnetic oven panel leakage magnetic field distribution map are used to determine the first electromagnetic oven coil which has the greatest contribution to the leakage magnetic field power output of the first temperature measuring point, including the following steps:

[0030] When the pot is placed off-center, the pot position information is obtained by the position sensor;

[0031] According to the pot position information, the pre-stored power distribution table or the least square method is used to obtain the actual power distribution of the electromagnetic oven coil;

[0032] According to the coil power experiment, the leakage magnetic field intensity generated by each electromagnetic oven coil at different power on the electromagnetic oven panel is obtained, and a leakage magnetic field distribution map of the electromagnetic oven panel is generated by fitting;

[0033] According to the actual power distribution of the electromagnetic oven coil and the leakage magnetic field distribution map of the electromagnetic oven panel, a table lookup or weighted summation is performed to obtain the leakage magnetic field power output contribution of all electromagnetic oven coils to the first temperature measuring point and arrange them in descending order, and the first electromagnetic oven coil with the largest leakage magnetic field power output contribution is determined.

[0034] Through the above scheme, the method for accurately identifying the coil with the largest leakage magnetic field power output contribution is provided, so that the subsequent adjustment can be more targeted, and the control efficiency and accuracy are improved.

[0035] Preferably, it is judged whether the second actual temperature of the first temperature measuring point meets the downward trend, which is recorded as the first judgment result, and if the first judgment result is yes, the first adjustment strategy is defined as effective, including the following steps:

[0036] The first judgment is whether the second actual temperature of the first temperature measuring point decreases to below the preset safety temperature threshold and remains stable within the third time period;

[0037] Or, the first judgment is whether the second actual temperature of the first temperature measuring point presents a downward trend within the fourth time period;

[0038] The above judgments are all recorded as the first judgment result, and if the first judgment result is yes, the first adjustment strategy is defined as effective.

[0039] Through the above scheme, the standard for judging the effectiveness of the adjustment strategy is clear, the reliability of risk removal is ensured, and misjudgment is avoided.

[0040] Preferably, after defining that the electromagnetic oven has an external metal heating risk, the following steps are further included:

[0041] Enter the first mode, and collect the third actual temperature of all temperature measuring points at the third frequency within M consecutive time windows in the fourth time period;

[0042] In the i-th time window, the second temperature measuring point corresponding to the highest third actual temperature is obtained, and in the i+1-th time window, the third temperature measuring point corresponding to the highest third actual temperature is obtained, and the hotspot displacement vector from the second temperature measuring point to the third temperature measuring point is calculated;

[0043] In the consecutive N time windows, it is judged whether the moving direction of the hotspot displacement vector is highly consistent with the moving direction of the preset magnetic field peak point, which is recorded as the third judgment result;

[0044] determining whether the moving rate of the hotspot displacement vector is similar to the moving rate of the preset magnetic field peak value point;

[0045] determining whether the third actual temperature does not appear a decreasing trend, and recording as a fifth determination result;

[0046] if the third determination result, the fourth determination result and the fifth determination result are all yes, defining that the first mode is invalid.

[0047] Through the above scheme, the hotspot displacement vector analysis is introduced, which can more accurately determine whether the risk mode is invalid, avoid unnecessary safety intervention, and improve the intelligence of the system.

[0048] Preferably, after defining that the first mode is invalid, the method further comprises the following steps:

[0049] entering a second mode, and performing instantaneous switching of the magnetic field peak value in a pseudo-random sequence between a plurality of non-continuous preset magnetic field peak value points;

[0050] During the instantaneous switching, determining whether the third actual temperature decreases to below a preset safety temperature threshold and remains stable within a fifth time period, and recording as a sixth determination result;

[0051] if the sixth determination result is yes, and if there is no external metal heating risk of the electromagnetic oven, exiting the second mode.

[0052] Through the above scheme, the second mode after the first mode is invalid is provided, the magnetic field peak value is switched in a pseudo-random manner, the risk is further reduced, and the system robustness is improved.

[0053] Preferably, after determining whether the actual temperature rise rate of the first temperature measurement point is greater than a preset metal object induced temperature rise threshold, and recording as a second determination result, the method further comprises the following steps:

[0054] determining whether the actual temperature rise rate of a fourth temperature measurement point adjacent to the first temperature measurement point presents a state of high absolute value but opposite direction, and recording as a seventh determination result;

[0055] if the second determination result and the seventh determination result are both yes, determining a first electromagnetic oven coil which has the greatest contribution to the leakage magnetic field power output of the first temperature measurement point according to the actual power distribution of the electromagnetic oven coil and the leakage magnetic field distribution map of the electromagnetic oven panel;

[0056] within the sixth time period, reducing and then restoring the second power value of the first electromagnetic oven coil, fitting to generate an energy disturbance curve of the first electromagnetic oven coil, and collecting the fourth actual temperature of the first temperature measurement point at a third frequency to fit to generate a temperature change curve of the first temperature measurement point;

[0057] determine whether the temperature change curve of the first temperature measuring point and the energy disturbance curve of the first electromagnetic induction cooker coil present a highly synchronized response on the time axis of the sixth time period, and record the result as an eighth determination result;

[0058] If the eighth determination result is yes, it is defined that the first temperature measuring point is at risk of being heated by an external metal and the temperature change of the fourth temperature measuring point is caused by a non-electromagnetic event, and the process enters the first mode.

[0059] An electromagnetic induction cooker heating process control system applied to a local leakage magnetic field scenario, comprising:

[0060] A risk type determination module is configured to collect the first actual temperature of all temperature measuring points on the panel of the electromagnetic induction cooker at a first frequency within a first time period, calculate the actual temperature rise rate of each temperature measuring point, and determine the risk type of the electromagnetic induction cooker when the actual temperature rise rate of the first temperature measuring point meets a preset condition.

[0061] A coil power output contribution determination module is configured to obtain the position information of the pot when the pot is placed off-center, obtain the actual power distribution of the electromagnetic induction cooker coil according to the position information of the pot, and determine the first electromagnetic induction cooker coil with the largest leakage magnetic field power output contribution to the first temperature measuring point according to the actual power distribution of the electromagnetic induction cooker coil and the leakage magnetic field distribution map of the panel of the electromagnetic induction cooker.

[0062] A first adjustment module is configured to modulate the pulse width modulation duty cycle of the first electromagnetic induction cooker coil with a first periodic waveform amplitude at a first adjustment frequency according to a first adjustment strategy.

[0063] A first determination module is configured to collect the second actual temperature of the first temperature measuring point at a second frequency after the modulation is completed, determine whether the second actual temperature of the first temperature measuring point meets a downward trend, and define the first adjustment strategy effective and record the result as a first determination result if the first determination result is yes.

[0064] The present application also provides an electromagnetic induction cooker heating process control system, which, due to the same technical concept, solves the same technical problem and should have the same beneficial effects, and thus will not be described here. BRIEF DESCRIPTION OF DRAWINGS

[0065] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the embodiments or the prior art description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0066] Figure 1 A flowchart of an electromagnetic induction cooker heating process control method provided by the embodiments of the present application;

[0067] Figure 2 Flowchart of step S1 provided for the embodiments of the present application;

[0068] Figure 3 Flowchart of step S2 provided for the embodiments of the present application;

[0069] Figure 4 Flowchart provided for the embodiments of the present application after step A4;

[0070] Figure 5 Flowchart provided for the embodiments of the present application after step C6;

[0071] Figure 6 Flowchart provided for the embodiments of the present application after step A3;

[0072] Figure 7 Structural schematic diagram of an electromagnetic oven heating process control system provided for the embodiments of the present application. DETAILED DESCRIPTION

[0073] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0074] The embodiments of the present application are written in a progressive manner.

[0075] The conventional existing magnetic field balancing electromagnetic oven, when heating a non-central placed pot, in order to achieve heating uniformity, its power distribution strategy will produce a concentrated leakage magnetic field in the panel area outside the pot. When the user performs a regular operation, such as placing a metal utensil, causing the leakage magnetic field to trigger a safety alarm, the existing control method, due to its fixed safety priority logic, can only eliminate the alarm by interrupting the heating, thus causing the cooking task to fail and falling into an invalid cycle bound to the user's behavior.

[0076] At this time, the induction hob system will continue to operate in a functionally deadlocked state. The system will repeatedly enter a cycle in which its performance-oriented heating strategy, designed to achieve heating uniformity, inadvertently creates a safety hazard. Once the hazard is detected, a safety-prioritized response is triggered, which unconditionally interrupts the main cooking task. This interruption leads to incomplete cooking tasks, energy waste, and a degraded user experience. Furthermore, the system cannot distinguish between transient, localized safety risks and basic operational faults, meaning it cannot adapt its behavior and thus permanently requires manual intervention to restart those tasks that are prone to interruption again. This compromises the reliability and autonomy of the device, limiting its practicality in complex or long cooking scenarios.

[0077] Based on this, as Figure 1 shown, an induction hob heating process control method applied to a local leakage magnetic field scenario includes the following steps:

[0078] S1. In a first time period, collect the first actual temperature of all temperature measurement points of the induction hob panel at a first frequency, calculate the actual temperature rise rate of each temperature measurement point, and determine the risk type of the induction hob when the actual temperature rise rate of the first temperature measurement point meets the preset condition.

[0079] S2. When the pot is placed off-center, obtain the pot position information, obtain the actual power distribution of the induction hob coil according to the pot position information, and determine the first induction hob coil with the largest contribution to the leakage magnetic field power output of the first temperature measurement point according to the actual power distribution of the induction hob coil and the leakage magnetic field distribution map of the induction hob panel.

[0080] S3. According to the first adjustment strategy, modulate the pulse width modulation duty cycle of the first induction hob coil with a first periodic waveform amplitude at a first adjustment frequency.

[0081] S4. After modulation, collect the second actual temperature of the first temperature measurement point at a second frequency, judge whether the second actual temperature of the first temperature measurement point meets the downward trend, record as the first judgment result, if the first judgment result is yes, define the first adjustment strategy effective.

[0082] The first frequency in step S1 refers to the sampling frequency of collecting temperature data of all temperature measurement points on the induction cooker panel within a first time period, which can be a fixed frequency such as 10 Hz or 20 Hz per second; all temperature measurement points on the induction cooker panel refer to multiple temperature sensors distributed below or inside the induction cooker panel for monitoring the temperature of different areas of the panel, which can be implemented by using thermistors, thermocouples or infrared temperature sensors, etc.; the first actual temperature refers to the temperature value collected by each temperature measurement point on the induction cooker panel in real time within the first time period; the actual temperature rise rate refers to the temperature rise amplitude of each temperature measurement point per unit time, which can be calculated by the difference between the current temperature (T_current) and the temperature at the previous moment (T_perevious) divided by the time interval (△t), for example ; the first temperature measurement point refers to a specific temperature measurement point on the induction cooker panel whose temperature or temperature rise rate reaches or exceeds a preset threshold, which is usually the area with the most significant abnormal temperature rise on the panel; the risk type of the induction cooker refers to whether the induction cooker currently has an external metal heat risk caused by a leaked magnetic field according to whether the actual temperature rise rate of the first temperature measurement point meets a preset condition (e.g., greater than a certain threshold);

[0083] In step S2, the off-center placement of the pot refers to the geometric center of the pot being a certain distance away from the geometric center of the heating area of the induction cooker, not being completely aligned, which can be determined by using visual recognition, inductive coupling detection or pressure sensor array technology; the pot position information refers to the specific position coordinates or deviation degree of the pot on the induction cooker panel, which can be obtained by using image processing technology, multi-point inductive detection or ultrasonic ranging; the actual power distribution of the induction cooker coils refers to the specific power output ratio or value of multiple heating coils inside the induction cooker under the current working state, which can be obtained by real-time monitoring of the current and voltage of each coil using current sensors, or by the power output instructions inside the control system; the leakage magnetic field distribution map of the induction cooker panel refers to a two-dimensional or three-dimensional data model reflecting the leakage magnetic field intensity distribution of each area of the induction cooker panel under different coil power distribution, which is established by experiment or simulation in advance; the first induction cooker coil refers to the heating coil determined to have the largest contribution to the leakage magnetic field power output of the first temperature measurement point according to the pot position information, the actual power distribution of the induction cooker coils and the leakage magnetic field distribution map of the induction cooker panel;

[0084] The first adjustment strategy in step S3 refers to a specific rule or algorithm for adjusting the pulse width modulation duty cycle of the first electromagnetic oven coil, which can adopt PID control, fuzzy control or control based on a lookup table; the first adjustment frequency refers to the frequency of the modulation operation on the pulse width modulation duty cycle of the first electromagnetic oven coil; the pulse width modulation duty cycle refers to adjusting the average power output of the electromagnetic oven coil by changing the ratio of the width to the period of the power supply pulse; the first periodic waveform amplitude refers to the amplitude of the modulation waveform when the pulse width modulation duty cycle is periodically modulated, which can adopt a sine wave, a square wave or a triangular wave, etc.

[0085] The second frequency in step S4 refers to the sampling frequency of the second actual temperature of the first temperature measurement point after modulation is completed; the second actual temperature refers to the temperature value collected by the first temperature measurement point in real time after modulation is completed; the downward trend refers to the downward trend of the second actual temperature of the first temperature measurement point over time.

[0086] Steps S1 to S4 combine real-time monitoring of the temperature rise rate of the electromagnetic oven panel temperature measurement point with the coil power distribution and leakage magnetic field distribution map under the condition of eccentric placement of the pot, thereby accurately identifying and locating the main coil that causes the risk of local overheating, and further modulating the pulse width modulation duty cycle of the main coil by a periodic waveform amplitude, achieving the effect of effectively suppressing the safety risk caused by local leakage magnetic field without interrupting the cooking task, while maintaining the uniformity of heating. This avoids the failure of the cooking task and the decline of user experience caused by the simple and rough interruption of heating in the traditional safety mechanism, realizes the balance between safety and cooking continuity, and improves the intelligence and user friendliness of the electromagnetic oven.

[0087] In some preferred embodiments, the application is implemented as follows: a control unit of an electromagnetic cooker, such as a high-performance microcontroller, collects first actual temperature data of each temperature measurement point at a frequency of 20 times per second in a first time period through a plurality of thermistor sensor arrays connected below the panel of the electromagnetic cooker. The microcontroller then executes an algorithm to calculate the actual temperature rise rate of each temperature measurement point. When the actual temperature rise rate of a certain temperature measurement point (e.g., the first temperature measurement point) is detected to exceed a preset threshold of 5 degrees Celsius per second, the system determines that the electromagnetic cooker has an external metal heating risk. At the same time, when the pot is placed off-center, the inductive position sensor built into the electromagnetic cooker obtains real-time two-dimensional coordinate information of the pot on the panel. The microcontroller obtains the actual power output ratio of each heating coil in the current multi-coil electromagnetic cooker according to the obtained pot position information and consults the pre-stored power distribution lookup table. Combined with the electromagnetic field distribution map of the electromagnetic cooker panel generated in advance by electromagnetic field simulation software, the microcontroller calculates the contribution of each coil to the leakage magnetic field power output of the first temperature measurement point and identifies the first electromagnetic cooker coil with the largest contribution. Then, the microcontroller adjusts the pulse width modulation duty cycle of the first electromagnetic cooker coil according to a preset first adjustment strategy (e.g., a fuzzy logic-based control algorithm) at an adjustment frequency of 1 time per second, and periodically modulates the amplitude of the sinusoidal wave by ±5% of the duty cycle. After the modulation operation is completed, the microcontroller collects second actual temperature of the first temperature measurement point at a frequency of 10 times per second. If the second actual temperature continues to show a downward trend in the next 10 seconds, the system confirms that the first adjustment strategy is effective and continues to execute the strategy to maintain a safe state.

[0088] Preferably, after determining the risk type of the first electromagnetic cooker coil and the first temperature measurement point, the following steps are further included:

[0089] According to the second adjustment strategy, the first power value of the first electromagnetic cooker coil is periodically transferred to the second electromagnetic cooker coil with lower leakage magnetic field power output contribution in a second time period.

[0090] The second adjustment strategy refers to a control logic for optimizing the power distribution of the induction cooker. Specifically, the power transfer amplitude and frequency can be dynamically adjusted according to the preset power transfer rule, real-time monitoring of the leakage magnetic field strength, or the state of the pot heating. The second time period refers to the time interval for power transfer operation, which can be a fixed time period, such as a few seconds or tens of seconds, or a dynamically adjusted period based on system state. The first power value refers to the amount of power transferred from the first induction coil, which can be a preset fixed power value or a dynamically calculated power value based on risk level or heating demand. The second induction coil with lower leakage magnetic field power output contribution refers to the induction coil on the induction cooker panel that produces relatively small leakage magnetic field strength during operation, or the induction coil whose leakage magnetic field region is far away from the first temperature measurement point. The specific determination can be made through electromagnetic field simulation, experimental testing, or preset configuration.

[0091] The above steps are specific implementation details after determining the risk type of the first induction coil and the first temperature measurement point. By periodically transferring the first power value of the first induction coil to the second induction coil with lower leakage magnetic field power output contribution according to the second adjustment strategy within the second time period, the local power output of the high leakage magnetic field contribution coil can be effectively reduced, thereby suppressing the intensity of the leakage magnetic field and reducing the risk of induction heating of metal objects. At the same time, since the power is transferred rather than simply reduced or interrupted, the overall heating power of the pot is maintained, avoiding forced interruption of the cooking task, thereby maintaining the continuity of the heating process and user experience while ensuring safety.

[0092] In some preferred embodiments, the application is implemented as follows: when the control system of the induction cooker collects the first actual temperatures of all temperature measuring points on the panel of the induction cooker at a first frequency within a first time period and calculates that the actual temperature rise rate of the first temperature measuring point meets the condition, for example, exceeds the preset threshold of the induced temperature rise of the metal object, the system will determine that the induction cooker has an external metal heating risk. Subsequently, the system will determine the first induction cooker coil that contributes most to the leakage magnetic field power output of the first temperature measuring point according to the pot position information and the leakage magnetic field distribution map of the panel of the induction cooker. On this basis, in addition to modulating the pulse width modulation duty cycle of the first induction cooker coil according to the first adjustment strategy, the system will also adjust the power transfer ratio and period based on the risk level according to the second adjustment strategy. Specifically, within a second time period, for example, every 5 seconds, the system will periodically transfer the first power value of the first induction cooker coil, for example, 20% of its current output power, to a second induction cooker coil with lower leakage magnetic field power output contribution. This second induction cooker coil can be a coil adjacent to the first induction cooker coil but with less impact on the first temperature measuring point, or a auxiliary coil specially used to absorb excess power. Through this periodic power transfer, the instantaneous power peak value of the first induction cooker coil at a certain moment can be effectively reduced, thereby suppressing the local leakage magnetic field generated by it, while maintaining the overall heating effect of the pot through the compensation heating of the second induction cooker coil, avoiding cooking interruption.

[0093] Preferably, after judging whether the second actual temperature of the first temperature measuring point meets the downward trend and recording the first judgment result, the following steps are included:

[0094] If the first judgment result is no, the first adjustment frequency is raised to the second adjustment frequency or the first periodic waveform amplitude is raised to the second periodic waveform amplitude;

[0095] According to the first adjustment strategy, the pulse width modulation duty cycle of the first induction cooker coil is modulated at the second adjustment frequency with the first periodic waveform amplitude as the first adjustment scheme;

[0096] Or, according to the first adjustment strategy, the pulse width modulation duty cycle of the first induction cooker coil is modulated at the first adjustment frequency with the second periodic waveform amplitude as the second adjustment scheme;

[0097] Or, when the first adjustment scheme or the second adjustment scheme is adopted, the second adjustment strategy is executed in parallel.

[0098] The second adjustment frequency refers to a frequency value higher than the first adjustment frequency; the second periodic waveform amplitude refers to an amplitude value greater than the first periodic waveform amplitude; the first adjustment scheme refers to a specific adjustment strategy in which the second adjustment frequency is used to modulate the pulse width modulation duty cycle of the first electromagnetic oven coil while maintaining the first periodic waveform amplitude unchanged; the second adjustment scheme refers to another specific adjustment strategy in which the first adjustment frequency is used to modulate the pulse width modulation duty cycle of the first electromagnetic oven coil while increasing the periodic waveform amplitude to the second periodic waveform amplitude; and parallel execution refers to starting and executing the second adjustment strategy independently and in parallel while executing the first adjustment scheme or the second adjustment scheme.

[0099] The above steps are performed after the first judgment in step S4, and when the first adjustment strategy of the electromagnetic oven fails to effectively reduce the temperature of the local leakage magnetic field region, the system can adaptively take further optimization measures. Specifically, by increasing the modulation frequency or increasing the periodic waveform amplitude, the intensity and distribution of the leakage magnetic field can be more actively intervened, thereby effectively reducing the temperature of the first temperature measurement point. In addition, by running the second adjustment strategy in parallel, that is, combined with power transfer, it can synergize from multiple aspects to further enhance the inhibition ability of local overheating. This enables the electromagnetic oven to avoid interrupting heating due to safety protection when facing continuous or stubborn local leakage magnetic field risks, thereby ensuring the continuity of the cooking task, effectively eliminating safety hazards, and improving the stability and user experience of the electromagnetic oven.

[0100] In some preferred embodiments, the application is implemented as follows: assuming that the electromagnetic oven is in operation, the second actual temperature of the first temperature measurement point (for example, a certain temperature sensor on the electromagnetic oven panel near the edge of the pot) after the intervention of the first adjustment strategy (i.e. the pulse width modulation duty cycle of the first electromagnetic oven coil is modulated with the first periodic waveform amplitude at the first adjustment frequency), the system first judges that the temperature does not show a downward trend. This indicates that the first adjustment strategy has failed to effectively suppress local overheating in this area. At this time, the control unit of the electromagnetic oven can select an optimization scheme according to the preset logic or real-time evaluation results. For example, the control unit can decide to use the first adjustment scheme. Specifically, if the original first adjustment frequency is 10 Hz, the control unit can increase the adjustment frequency to a second adjustment frequency, for example, 20 Hz. At the same time, keep the first periodic waveform amplitude unchanged, for example, still 5%. Then, the control unit will modulate the pulse width modulation duty cycle of the first electromagnetic oven coil with the amplitude of 5% at the frequency of 20 Hz according to the first adjustment strategy. This faster modulation frequency aims to accelerate the fluctuation of the leakage magnetic field, thereby faster removing local heat. As another specific embodiment, the control unit can also choose to use the second adjustment scheme. For example, if the original first periodic waveform amplitude is 5%, the control unit can increase the amplitude to a second periodic waveform amplitude, for example, 10%. At the same time, keep the first adjustment frequency unchanged, for example, still 10 Hz. Then, the control unit will modulate the pulse width modulation duty cycle of the first electromagnetic oven coil with the amplitude of 10% at the frequency of 10 Hz according to the first adjustment strategy. This larger waveform amplitude aims to cause more significant power changes during each modulation, thereby more effectively suppressing the leakage magnetic field. In addition, when using the above first adjustment scheme or second adjustment scheme, the control unit can also run the second adjustment strategy in parallel. Specifically, while executing, for example, the first adjustment scheme (increasing the frequency), the control unit can periodically transfer a portion of the power value (for example, the first power value) of the first electromagnetic oven coil to the second electromagnetic oven coil, which has a lower contribution to the leakage magnetic field power output. This power transfer can be synchronized with the adjustment of the pulse width modulation duty cycle, or performed independently. For example, every 5 seconds, 10% of the power of the first electromagnetic oven coil is transferred to the second electromagnetic oven coil for 1 second, while the pulse width modulation duty cycle of the first electromagnetic oven coil is still modulated at the increased frequency and amplitude. In this way, the system can intervene in local overheating from two dimensions (modulation parameter optimization and power distribution adjustment) at the same time, thereby improving the success rate of solving the problem and ensuring that the electromagnetic oven can effectively manage the temperature risk caused by local leakage magnetic field without interrupting heating.

[0101] As Figure 2As shown, preferably, in the first time period, the first actual temperature of all temperature measuring points of the induction cooker panel is collected at a first frequency, the actual temperature rise rate of each temperature measuring point is calculated, and when the actual temperature rise rate of the first temperature measuring point meets the preset condition, the risk type of the induction cooker is determined, including the following steps:

[0102] A1. In the first preset period, according to the thermistor sensor and the digital converter of each temperature measuring point, the first actual temperature data of all temperature measuring points is collected at a first frequency;

[0103] A2. The actual temperature rise rate of each temperature measuring point is calculated according to the temperature rise rate formula;

[0104] A3. Determine whether the actual temperature rise rate of the first temperature measuring point is greater than the preset metal object induced temperature rise threshold, and record it as the second judgment result;

[0105] A4. If the second judgment result is yes, it is defined that the induction cooker has an external metal heat risk.

[0106] Among them, the first preset period in step A1 refers to the time window for temperature data collection and risk judgment, which can be flexibly configured according to the response speed requirement of the induction cooker and the system resource situation, for example, it can be a fixed time length, or it can be a dynamically adjusted period; The thermistor sensor refers to a temperature sensitive element whose resistance value changes with temperature, which can use negative temperature coefficient thermistor or positive temperature coefficient thermistor, etc.; The digital converter refers to an electronic circuit or device that converts analog electrical signal to digital signal, which can use analog-to-digital converter chip or ADC module integrated in microcontroller; The first frequency refers to the sampling rate of temperature data collection in the first preset period, which can be set according to the expected speed of temperature change and the real-time requirement of the system, for example, it can be a fixed sampling rate, or it can be a dynamically adjusted sampling rate according to the working state of the induction cooker;

[0107] The temperature rise rate formula in step A2 refers to the mathematical expression for calculating the temperature change speed of the temperature measuring point, which can use the difference between the current temperature and the temperature at the previous time divided by the difference of time interval, or use more complex algorithms such as sliding average, least square fitting, etc.

[0108] The preset metal object induced temperature rise threshold in step A3 refers to the critical value for distinguishing normal temperature rise and metal object induced heat temperature rise, which can be calibrated according to the normal working characteristics of the induction cooker, the environmental temperature, and the experimental data of typical metal objects in the leakage magnetic field.

[0109] Steps A1 to A3 are specific details of step S1, which is to capture the sharp temperature rise caused by the induction heating of metal objects and distinguish it from the temperature change in the normal working state by collecting temperature data in real time and calculating the temperature rise rate. This judgment mechanism based on the temperature rise rate avoids misjudgment or delayed judgment that may be caused by relying only on temperature thresholds, thereby providing timely and accurate basis for subsequent risk response strategies, effectively improving the safety of induction cooker operation, and laying a foundation for intelligent and safe control without interrupting the cooking task.

[0110] In some preferred embodiments, the present application is implemented as follows: after the control system of the induction cooker is started, it will continuously enter a risk monitoring cycle. In this cycle, the system sets a first preset period, for example, every 500 milliseconds. Within this period, the system collects temperature data at a first frequency, for example, every millisecond, for all temperature measurement points through multiple NTC thermistor sensors integrated under the panel of the induction cooker, combined with the 12-bit ADC digital converter inside the microcontroller. The first actual temperature data collected is stored in a ring buffer. Subsequently, the control system calculates the current actual temperature rise rate of each temperature measurement point using the temperature rise rate formula. For example, for a certain temperature measurement point, its temperature rise rate can be calculated as the difference between the current collected temperature and the previous collected temperature divided by the time interval between the two collections. The system continuously monitors the temperature rise rates of all temperature measurement points, and pays special attention to the first temperature measurement point, which is usually the area on the panel that is most susceptible to the leakage magnetic field. Then, the system secondly judges whether the actual temperature rise rate of the first temperature measurement point is greater than the preset metal object induction temperature rise threshold. This threshold can be calibrated according to the temperature rise characteristics of the panel of the induction cooker when there is no pot or normal pot heating, and the temperature rise experimental data of the panel when a small metal object such as a spoon is placed, for example, it can be set to 5 degrees Celsius per second. If the temperature rise rate of the first temperature measurement point exceeds this threshold, the system will immediately determine that there is an external metal heating risk. If the second judgment result is yes, i.e. the temperature rise rate exceeds the threshold, the system will define that the induction cooker currently has an external metal heating risk. At this time, the control system can trigger the corresponding safety response mechanism, for example, issue an alarm to the user, or prepare to execute subsequent power adjustment or magnetic field reshaping strategies to eliminate the risk while trying not to interrupt the current cooking task.

[0111] As shown in Figure 3 Preferably, when the pot is placed off-center, the pot position information is obtained, the actual power distribution of the induction cooker coils is obtained according to the pot position information, and the first induction cooker coil that contributes most to the leakage magnetic field power output of the first temperature measurement point is determined according to the actual power distribution of the induction cooker coils and the leakage magnetic field distribution map of the induction cooker panel, including the following steps:

[0112] B1. Obtain the pot position information through the position sensor when the pot is placed off-center;

[0113] B2. Obtain the actual power distribution of the induction cooker coils according to the pot position information by querying the pre-stored power distribution table or using the least squares method;

[0114] B3. Obtain the leakage magnetic field intensity generated by each induction cooker coil at different power levels on the induction cooker panel through coil power experiments, and generate the induction cooker panel leakage magnetic field distribution map by fitting;

[0115] B4. Obtain the leakage magnetic field power output contribution of all induction cooker coils to the first temperature measurement point and arrange them in descending order by table lookup or weighted summation according to the actual power distribution of the induction cooker coils and the induction cooker panel leakage magnetic field distribution map, and determine the first induction cooker coil with the largest leakage magnetic field power output contribution.

[0116] The position sensor in step B1 refers to a device for detecting the specific placement position of the pot on the induction cooker panel, which can be implemented using an inductive sensor, a Hall sensor array, a visual recognition system, or a pressure sensor, etc.

[0117] The pre-stored power distribution table in step B2 refers to a set of induction cooker coil power output ratios or values pre-stored in the system for different pot positions and heating requirements, which can be implemented using a lookup table, a database, or a hard-coded data structure. The least squares method refers to a mathematical optimization technique used to find the best function match of data by minimizing the sum of squares of errors, which can be implemented using linear regression, polynomial fitting, or nonlinear fitting algorithms.

[0118] The coil power experiment in step B3 refers to a series of test processes that apply different power to a single or multiple induction cooker coils under controlled conditions and measure the leakage magnetic field intensity generated at a specific location on the induction cooker panel. It can be implemented using a magnetic field intensity meter, an oscilloscope combined with an inductive coil, or a special magnetic field measurement device. Leakage magnetic field intensity refers to the magnetic field intensity formed on the surface of the induction cooker panel or in the surrounding space when the magnetic field generated by the induction cooker coil is not completely absorbed by the pot. It can be measured using a Tesla meter or a Gauss meter. The induction cooker panel leakage magnetic field distribution map refers to a two-dimensional or three-dimensional data model reflecting the spatial distribution of magnetic field intensity on the entire panel area generated by measuring and fitting the leakage magnetic field intensity of multiple points on the induction cooker panel. It can be presented in the form of a heat map, contour map, or three-dimensional surface plot.

[0119] The table lookup in step B4 refers to the operation of finding the corresponding output value in a pre-established data structure (such as a table, array or map) according to the input parameters, which can be implemented by hash table lookup, binary search or direct index lookup; weighted summation refers to the calculation method of multiplying multiple numerical values by their corresponding weight coefficients and then accumulating, which can be implemented by linear combination, matrix multiplication or the weighted layer of neural network; descending order refers to the process of reorganizing a set of data in the order of numerical values from large to small, which can be implemented by quicksort, mergesort or heapsort algorithm.

[0120] Steps B1 to B4 are the specific implementation details of step S2, which can avoid misjudgment caused by insufficient information or rough judgment in traditional methods by comprehensively considering the actual position of the pot, the real-time power distribution of the induction cooker coil and the leakage magnetic field distribution characteristics of the panel. Specifically, the introduction of the position sensor ensures the accuracy of the pot position information, the combination of the pre-stored power distribution table and the least squares method provides a flexible and accurate power distribution acquisition method, and the establishment of the coil power experiment and the leakage magnetic field distribution map provides a reliable data basis for quantifying the magnetic field effect. Finally, through table lookup or weighted summation and descending order, the system can accurately identify the coil that contributes most to the risk of local overheating, thereby providing a clear and reliable target for subsequent risk processing and power adjustment, significantly improving the accuracy and effectiveness of the safety control of the induction cooker in the scene of placing the pot off-center.

[0121] In some preferred embodiments, the application is implemented as follows. When the pot is placed off-center, the induction cooker can obtain the pot position information through a capacitive sensor array integrated under the panel. The array can detect the effect of the pot bottom on the capacitive field, thereby calculating the center coordinates and approximate size of the pot. After obtaining the pot position information, the main control unit of the induction cooker, such as a high-performance microcontroller, can first try to query the pre-stored power distribution table according to the position information. The power distribution table can be a two-dimensional array, whose indices correspond to different pot offset areas, and stores the pre-set power distribution ratios of each heating coil. If the current pot position highly matches a typical position in the pre-stored table, the corresponding power distribution scheme is directly adopted. If the position deviates greatly or requires more precise control, the microcontroller can start the least squares algorithm to calculate the actual power distribution of each induction cooker coil in real time according to the actual position of the pot and the pre-set heating uniformity target. During the production or calibration stage of the induction cooker, detailed coil power experiments will be conducted. Specifically, a high-precision magnetic field intensity meter is placed at multiple pre-set temperature measurement points on the induction cooker panel, and then each induction cooker coil is applied with different power levels from low to high one by one or in combination, and the leakage magnetic field intensity data corresponding to each temperature measurement point is recorded. These data are then imported into data processing software to generate a detailed induction cooker panel leakage magnetic field distribution map through interpolation and fitting algorithms. This map can be stored as a high-resolution two-dimensional matrix, where each element represents the magnetic field intensity contribution of the corresponding position on the panel at unit power. In actual operation, when the actual power distribution of the induction cooker coil is obtained, the main control unit will combine this induction cooker panel leakage magnetic field distribution map. For the first temperature measurement point, the system can traverse all induction cooker coils. For each coil, the leakage magnetic field intensity value generated by the coil at the first temperature measurement point under the current power is obtained by consulting the leakage magnetic field distribution map. If more accurate calculation is required, the weighted summation method can be used to multiply the actual power of each coil by its magnetic field contribution coefficient at the first temperature measurement point, and then accumulate to obtain the total leakage magnetic field power output contribution. For example, if the induction cooker has four coils, the system will calculate the contribution value of each coil to the first temperature measurement point. Finally, the leakage magnetic field power output contribution values of all coils are arranged in descending order, and the coil ranked first is determined as the first induction cooker coil with the largest leakage magnetic field power output contribution.

[0122] Preferably, it is judged whether the second actual temperature of the first temperature measurement point meets a downward trend, which is recorded as a first judgment result, and if the first judgment result is yes, it is defined that the first adjustment strategy is effective, including the following steps:

[0123] It is judged whether the second actual temperature of the first temperature measurement point decreases to below the pre-set safety temperature threshold and remains stable within a third time period;

[0124] or, judging whether the second actual temperature of the first temperature measuring point presents a downward trend in a fourth time period;

[0125] The above judgments are recorded as first judgment results, and if the first judgment results are yes, the first adjustment strategy is defined as valid.

[0126] The third time period refers to a specific time period for evaluating whether the temperature is decreasing and stable, which can be set according to the response speed of the induction cooker, the material heat capacity, and the safety requirement; the preset safety temperature threshold refers to the maximum temperature limit that the induction cooker panel or the specific temperature measuring point should not exceed in the normal safe operation state, which can be determined according to the design specification of the induction cooker, the material heat resistance, and the user safety standard; the stable refers to that, in the third time period, after the second actual temperature of the first temperature measuring point decreases to the preset safety temperature threshold, the temperature fluctuation range of the first temperature measuring point is within a very small preset interval, for example, the temperature change rate is lower than a certain minimum value, or the temperature value fluctuates around the preset safety temperature threshold by no more than a certain small amount; the fourth time period refers to another time period for evaluating whether the temperature presents a downward trend, which can be different from the third time period, for example, shorter; the downward trend refers to that, in the fourth time period, the overall change direction of the second actual temperature of the first temperature measuring point is downward, which can be achieved by calculating the linear regression slope of the temperature sequence as a negative value, or by comparing the temperature values of the starting point and the ending point, or by judging whether the temperature values of the continuous multiple sampling points are decreasing.

[0127] The above steps are specific implementation modes of the first judgment being yes in step S4, which introduces the judgment condition of the temperature decreasing to the preset safety temperature threshold and being stable, to ensure that the temperature not only can effectively decrease, but also can be long-term stable in the safety range, thereby effectively preventing the situation that the temperature fluctuates or decreases and then rises again, and significantly improving the safety control ability of the induction cooker in the local leakage magnetic field scenario. At the same time, the judgment of the downward trend is reserved as a supplement, so that the system can flexibly evaluate the strategy effect in different situations, thereby improving the overall safety and user experience of the induction cooker.

[0128] In some preferred embodiments, after the first adjustment strategy modulates the pulse width modulation duty cycle of the first induction cooker coil, the control system of the induction cooker collects the second actual temperature of the first temperature measuring point at a frequency of 10 times per second. The system first determines whether the second actual temperature of the first temperature measuring point has dropped below a preset safety temperature threshold, for example 60 degrees Celsius, and remained stable, for example with a temperature fluctuation range of less than 1 degree Celsius, within a third time period of, for example, 30 seconds. Alternatively, the system determines whether the second actual temperature of the first temperature measuring point shows a downward trend within a fourth time period of, for example, 10 seconds, for example by calculating the linear regression slope of the temperature data within these 10 seconds, or determining whether the temperature values of the last 5 consecutive sampling points are decreasing. As long as the result of either of the above two determinations is yes, the control system defines the current first adjustment strategy as effective, and continues to execute the subsequent heating process control logic. This specific determination process enables the system to flexibly and accurately evaluate the actual effect of the adjustment strategy, ensuring that the induction cooker continues to operate safely.

[0129] As shown in Figure 4 Preferably, after defining that the induction cooker has an external metal heating risk, the following steps are further included:

[0130] C1. Enter the first mode, and collect the third actual temperature of all temperature measuring points at a third frequency within M consecutive time windows within a fourth time period;

[0131] C2. In the i-th time window, obtain the second temperature measuring point corresponding to the highest third actual temperature, and in the i+1-th time window, obtain the third temperature measuring point corresponding to the highest third actual temperature, and calculate the hotspot displacement vector from the second temperature measuring point to the third temperature measuring point;

[0132] C3. In the next N time windows, determine whether the moving direction of the hotspot displacement vector is highly consistent with the moving direction of the preset magnetic field peak point, and record as the third determination result;

[0133] C4. Determine whether the moving rate of the hotspot displacement vector is similar to the moving rate of the preset magnetic field peak point, and record as the fourth determination result;

[0134] C5. Determine whether the third actual temperature shows a downward trend, and record as the fifth determination result;

[0135] C6. If the third determination result, the fourth determination result and the fifth determination result are all yes, define that the first mode is invalid.

[0136] The first mode in step C1 refers to a specific operating state of the induction cooker system after a preliminary judgment of the existence of external metal heating risk, which can start a more detailed temperature data collection and analysis process; the fourth time period refers to the overall time period for heat point displacement analysis, the length of which can be set according to actual application requirements and system response speed; the M consecutive time windows refer to discrete time periods for continuous temperature data collection and heat point tracking within the fourth time period, and the duration of each time window can be relatively short; the third frequency refers to the sampling frequency of the third actual temperature data of all temperature measurement points on the induction cooker panel within the M consecutive time windows;

[0137] The heat point displacement vector in step C2 refers to the displacement vector of the hottest point (heat point) on the induction cooker panel from the previous position to the next position within two consecutive time windows, which contains the direction and distance information of the heat point movement;

[0138] The N time windows in step C3 refer to the number of consecutive time windows for judging whether the moving direction and rate of the heat point displacement vector are consistent with the preset magnetic field peak point height, and N is usually less than or equal to M;

[0139] The preset magnetic field peak point in step C4 refers to the area on the induction cooker panel with high magnetic field strength determined in advance or calibrated through experiments according to the layout of the induction cooker coil, power distribution and magnetic field leakage characteristics. These areas are usually the path where the heat point may appear or move when the external metal object is inductively heated.

[0140] Steps C1 to C6 are specific implementation details after step A4, after a preliminary judgment of the risk, the risk is verified again by introducing heat point displacement vector analysis and temperature trend judgment. Specifically, by collecting temperature data of all temperature measurement points on the panel within multiple consecutive time windows and tracking the movement trajectory of the heat point, the dynamic characteristics of the heat source can be identified. Further, by judging whether the moving direction and rate of the heat point displacement vector are highly consistent with the moving direction and rate of the preset magnetic field peak point, and whether the temperature shows a downward trend, the induction heating of metal objects caused by leakage magnetic field can be effectively distinguished from local temperature rise caused by other non-metal heating factors (such as internal component aging, environmental temperature change or sensor false alarm). This significantly reduces the occurrence of false judgments and avoids unnecessary heating interruptions caused by false judgments, thereby improving the safety and user experience of the induction cooker and ensuring the continuity and stability of the cooking process.

[0141] In some preferred embodiments, the application is implemented as follows. When the control system of the induction cooker initially judges that there is a risk of external metal heating by analyzing the temperature rising rate of the first temperature measuring point, the system will immediately switch to the first mode. In this mode, the temperature sensor array (for example, an NTC thermistor array or an infrared temperature sensor array) deployed below the induction cooker panel will continuously collect the third actual temperature data of all temperature measuring points in M consecutive time windows (for example, 1 second per window, a total of 30 windows) within a fourth time period (for example, lasting 30 seconds) at a third frequency (for example, collecting 10 times per second). These temperature data will be transmitted to the host unit (for example, an embedded microcontroller or digital signal processor). At the end of each time window, the host unit will analyze the third actual temperature data of all temperature measuring points in the current window, identify the temperature measuring point with the highest temperature, and mark it as the second temperature measuring point. At the end of the next time window, the temperature measuring point with the highest temperature is identified again and marked as the third temperature measuring point. Subsequently, the host unit will calculate the hotspot displacement vector based on the physical coordinates of the second temperature measuring point and the third temperature measuring point on the panel. For example, if the second temperature measuring point is located at (x1, y1) on the panel and the third temperature measuring point is located at (x2, y2), then the displacement vector is ((x2-x1), (y2-y1)). In the next N consecutive time windows (for example, 5 consecutive time windows), the host unit will continuously calculate and accumulate the hotspot displacement vector. At the same time, the system internally pre-stores typical moving direction and rate data of the peak leakage magnetic field point on the panel under different power distribution of the induction cooker. The host unit will thirdly judge whether the average moving direction of the currently accumulated hotspot displacement vector is highly consistent with the moving direction of the preset magnetic field peak point (for example, by calculating whether the vector angle is less than a certain threshold value). At the same time, the fourthly judges whether the average moving rate of the hotspot displacement vector is similar to the moving rate of the preset magnetic field peak point (for example, by comparing whether the rate difference is within the allowed range). In addition, the host unit will fifthly judge whether the third actual temperature has a downward trend during the entire fourth time period, or whether it is continuously rising or stable. If the above three judgment results are all yes, that is, the direction and rate of hotspot movement are highly matched with the characteristics of the leakage magnetic field, and the temperature is continuously rising, then the system will define the first mode as invalid. This means that although the initial single temperature measuring point temperature rise may have triggered an alarm, after more detailed analysis, the system confirms that it is not caused by external metal object induction heating, thereby avoiding unnecessary heating interruption. For example, this may be caused by sensor drift or local uneven heating of the panel, etc. non-metal heating factors.

[0142] As Figure 5 shown, preferably, after defining the first mode as invalid, the following steps are included:

[0143] D1. Enter the second mode, and perform instantaneous switching of the magnetic field peak in a pseudo-random sequence between multiple non-continuous preset magnetic field peak points;

[0144] D2. During the instantaneous switching process, determine whether the third actual temperature has fallen below the preset safety temperature threshold and remained stable within the fifth time period, and record the result as the sixth determination result;

[0145] D3. If the sixth determination result is yes, and if there is no external metal heating risk for the electromagnetic oven, exit the second mode.

[0146] The multiple non-continuous preset magnetic field peak points in step D1 refer to a number of regions on the electromagnetic oven panel that are pre-set and not adjacent in space. These regions can produce local magnetic field strength peaks under specific coil combinations or power distribution. They can be determined through simulation or experiment during the design phase of the electromagnetic oven and stored in the control system. The pseudo-random sequence refers to a sequence that appears random but is actually generated by a deterministic algorithm. It is used to control the order of switching the magnetic field peak between different preset points. It can be implemented using linear congruential method, Mason rotation algorithm, or other pseudo-random number generators. The instantaneous switching of the magnetic field peak refers to rapidly transferring the magnetic field peak from one preset point to another by adjusting the power output or phase of the electromagnetic oven coils within a short time. It can be implemented using a fast-response power regulation module or a high-frequency switching circuit.

[0147] Steps D1 to D3 are specific implementation details after step C6. When the first mode of the electromagnetic oven cannot effectively eliminate the external metal heating risk, the system can enter the second mode. By performing instantaneous switching of the magnetic field peak in a pseudo-random sequence between multiple non-continuous preset magnetic field peak points, the energy of the leaked magnetic field is effectively dispersed, avoiding the overheating of metal objects in a fixed position for a long time, thereby reducing the safety hazards. At the same time, by continuously monitoring the third actual temperature and determining whether it has fallen below the preset safety temperature threshold and remained stable, the effective elimination of the risk is ensured. When the risk is eliminated and there is no external metal heating risk, the system can exit the second mode and resume normal heating, thereby avoiding forced interruption of the cooking process and improving the continuity of cooking and user experience under the premise of ensuring safety.

[0148] In some preferred embodiments, when the control system of the electromagnetic cooker determines that the first mode is ineffective, for example, when it is monitored that the hotspot on the panel continues to follow the magnetic field peak of a certain coil and the temperature of the hotspot fails to drop within a specified time, the system can immediately enter the second mode. In the second mode, the microcontroller of the electromagnetic cooker can pre-store a set of non-continuous magnetic field peak point coordinates, for example, the upper left corner, the upper right corner, the lower left corner, the lower right corner of the panel and the specific positions of the central area. The system can use a pseudo-random number generator, for example, an algorithm based on a linear feedback shift register (LFSR), to generate a sequence that determines the order of switching the magnetic field peak between these preset points. For example, the system can first concentrate power in the upper left corner area for a short time, and then quickly transfer the power to the lower right corner area and then to the central area according to the next instruction of the pseudo-random sequence, and so on. This instantaneous switching can be achieved by quickly adjusting the pulse width modulation (PWM) duty cycle of different heating coils or enabling / disabling specific coil groups. During the process of instantaneous switching of the magnetic field peak, the system can continuously collect the third actual temperature data through the temperature sensor below the panel. For example, the temperature is collected every 100 milliseconds and compared with the preset safe temperature threshold. The system can determine whether the third actual temperature is continuously lower than or equal to the preset safe temperature threshold within a fifth time period, for example, 30 seconds, and remains at this level in subsequent multiple samplings. If these conditions are met, it indicates that the metal heating risk has been effectively mitigated. At this time, if the system confirms through other sensors or logic that there is no external metal heating risk in the electromagnetic cooker (for example, there is no longer an abnormal temperature rise area on the panel, or the user has removed the metal object), the system can exit the second mode and return to normal heating power output to continue the cooking task.

[0149] As Figure 6 shown, preferably, after determining whether the actual temperature rise rate of the first temperature measurement point is greater than the preset metal object induced temperature rise threshold, recording it as the second determination result, the following steps are further included:

[0150] E1. determining whether the actual temperature rise rate of the fourth temperature measurement point adjacent to the first temperature measurement point presents a high absolute value but opposite direction state, recording it as the seventh determination result;

[0151] E2. if both the second determination result and the seventh determination result are yes, determining the first electromagnetic cooker coil that contributes the most to the leakage magnetic field power output of the first temperature measurement point according to the actual power distribution of the electromagnetic cooker coil and the leakage magnetic field distribution map of the electromagnetic cooker panel;

[0152] E3. In the sixth time period, after the second power value of the first electromagnetic induction coil is reduced and restored, an energy perturbation curve of the first electromagnetic induction coil is fitted, and a fourth actual temperature of the first temperature measuring point is collected at a third frequency, and a temperature change curve of the first temperature measuring point is fitted;

[0153] E4. It is judged whether the temperature change curve of the first temperature measuring point and the energy perturbation curve of the first electromagnetic induction coil present a high degree of synchronous response on the time axis of the sixth time period, and the result is recorded as an eighth judgment result;

[0154] E5. If the eighth judgment result is yes, it is defined that the first temperature measuring point has an external metal heating risk and the temperature change of the fourth temperature measuring point is caused by a non-electromagnetic event, and enters the first mode.

[0155] The high absolute value but opposite direction state in step E1 refers to adjacent temperature measuring points, i.e. the first temperature measuring point and the fourth temperature measuring point, whose actual temperature rise rates are both large in value, but one presents an upward trend and the other presents a downward trend, or the upward rate is much larger than the downward rate, or vice versa, which can be determined by comparing the signs and values of the temperature rise rates of the two temperature measuring points, and is used to identify the typical temperature distribution characteristics caused by local electromagnetic induction heating, i.e. the phenomenon that the temperature in the center of the heat source rises and the temperature in the surrounding area decreases due to heat conduction, so as to distinguish electromagnetic induction heating from environmental factors or device self-heating;

[0156] In some preferred embodiments, the control system of the electromagnetic induction cooker presets a metal object induction heating temperature rise threshold, for example 5 degrees Celsius per second. When the actual temperature rise rate exceeds this threshold, the system confirms it as an "external metal object rapid heating" event. Therefore, in the "composite thermal field ambiguity state", if the temperature rise rate of the temperature sensor of the first temperature measuring point exceeds 5 degrees Celsius per second, the "high absolute value" of the temperature change rate of the temperature sensor of the fourth temperature measuring point can be understood as that the absolute value of its downward rate also reaches a level comparable to the upward rate of the temperature sensor of the first temperature measuring point, for example, the temperature change rate of the temperature sensor of the fourth temperature measuring point can be -5 degrees Celsius per second or lower (for example, -7.5 degrees Celsius per second), and its absolute value is 5 degrees Celsius per second or 7.5 degrees Celsius per second. A specific range example can be set as that when the absolute value of the temperature change rate of the temperature sensor of the fourth temperature measuring point is greater than or equal to 5 degrees Celsius per second, it is considered as a "high absolute value".

[0157] The energy perturbation curve in step E3 refers to a curve formed by presetting and controlling the instantaneous reduction and subsequent recovery of the power output of the electromagnetic oven coil within a certain time period, which can be specifically realized by controlling the driving circuit of the first electromagnetic oven coil to reduce the output power from the normal value to the second power value in a short time, then quickly recover to the normal value, and record the change of the power value with time in real time; the temperature change curve refers to a curve formed by fitting the temperature data of the first measuring point with time during the energy perturbation process, which can be specifically realized by sampling the fourth actual temperature of the first measuring point at a high frequency and connecting these discrete temperature points to form a continuous curve;

[0158] The high-synchronous response in step E4 refers to the close time correlation and consistent trend of the temperature change curve of the first measuring point and the energy perturbation curve of the first electromagnetic oven coil on the time axis, which can be specifically judged by calculating the cross-correlation coefficient, phase difference or observing whether the time points of the peak and valley values are consistent, for example, when the energy perturbation curve shows that the power is reduced, the temperature change curve also shows that the temperature is almost reduced at the same time, and when the power is restored, the temperature also rises.

[0159] Steps E1 to E5 are specific implementation details after step A3, which can preliminarily exclude false judgments caused by the structure of the electromagnetic oven itself or environmental factors by introducing the judgment of the temperature rise rate direction of the adjacent measuring point. Further, by perturbing the power of the specific electromagnetic oven coil and observing whether the temperature response of the affected measuring point presents a high synchronization, the present scheme can actively verify whether the temperature rise is indeed caused by electromagnetic induction, thereby accurately distinguishing the temperature change caused by external metal heating from non-electromagnetic events. This avoids unnecessary protective measures such as unnecessary power reduction or heating interruption due to false judgments, thereby improving the reliability of the safety protection mechanism of the electromagnetic oven and ensuring the continuity of the cooking process and user experience.

[0160] In some preferred embodiments, the application is implemented as follows: when the electromagnetic oven is in operation, its main control unit continuously monitors the temperature data collected by the multiple thermistor sensors distributed on the panel. Assuming that at a certain moment, the actual temperature rise rate detected by the temperature sensor of the first temperature measurement point located in a specific area of the panel exceeds the preset threshold value of the metal object induced temperature rise, this initially triggers a potential risk alarm. To further verify, the main control unit will immediately check the fourth temperature measurement point adjacent to the first temperature measurement point. If the actual temperature rise rate of the fourth temperature measurement point shows a high absolute value but opposite direction, for example, the temperature of the first temperature measurement point rises sharply while the temperature of the fourth temperature measurement point drops slightly or remains stable, this further enhances the judgment that there is local electromagnetic induction heating. Once both conditions are met, the main control unit will accurately identify the first electromagnetic oven coil that contributes the most to the leaked magnetic field power output in the first temperature measurement point area according to the pre-stored electromagnetic oven coil actual power distribution data and electromagnetic oven panel leaked magnetic field distribution map through table lookup or calculation. For example, if the first temperature measurement point is located in the front right of the electromagnetic oven panel, the system may identify the main heating coil in the front right or the auxiliary coil near it as the first electromagnetic oven coil with the greatest contribution. Subsequently, the main control unit will start an active verification process. Within a preset sixth time period, for example, for several seconds, the main control unit sends instructions to the driving circuit of the first electromagnetic oven coil to reduce its output power from the current value to a lower second power value, for example, to reduce the power by 20%, and quickly restore it to the original power after a short delay. In this process, the main control unit records the actual power output change of the first electromagnetic oven coil in real time and generates its energy disturbance curve. At the same time, the main control unit continuously collects the fourth actual temperature data of the first temperature measurement point at a higher third frequency, for example, 100 times per second, and uses these data to generate the temperature change curve of the first temperature measurement point. Finally, the main control unit performs an eighth judgment by analyzing the relationship between the two curves on the time axis of the sixth time period. For example, the system can calculate the cross-correlation coefficient of the two curves, if the coefficient is close to 1, and the temperature change curve and the energy disturbance curve are almost synchronous in time, it is considered that the two curves present a high degree of synchronous response. If the judgment result is yes, the system defines that the first temperature measurement point has an external metal heating risk, and at the same time, if the temperature change of the fourth temperature measurement point does not present a synchronous response to the energy disturbance of the first electromagnetic oven coil, it can be judged that the temperature change of the fourth temperature measurement point is caused by a non-electromagnetic event. At this time, the system will immediately enter the first mode, for example, start the corresponding safety protection measures, such as reducing the power output of the first electromagnetic oven coil or issuing an alarm, to avoid overheating of the metal object.

[0161] As shown in Figure 7 An electromagnetic oven heating process control system applied to a local leakage magnetic field scenario, comprising:

[0162] a risk type determination module configured to collect first actual temperatures of all temperature measuring points of the induction cooker panel at a first frequency in a first time period, calculate an actual temperature rise rate of each temperature measuring point, and determine a risk type of the induction cooker when the actual temperature rise rate of the first temperature measuring point meets a preset condition;

[0163] a coil power output contribution determination module configured to obtain pot position information when the pot is placed off-center, obtain actual power distribution of the induction cooker coil according to the pot position information, and determine a first induction cooker coil with the largest power output contribution to the leakage magnetic field of the first temperature measuring point according to the actual power distribution of the induction cooker coil and a leakage magnetic field distribution map of the induction cooker panel;

[0164] a first adjustment module configured to modulate a pulse width modulation duty cycle of the first induction cooker coil with a first periodic waveform amplitude at a first adjustment frequency according to a first adjustment strategy;

[0165] a first judgment module configured to collect a second actual temperature of the first temperature measuring point at a second frequency after the modulation is completed, judge whether the second actual temperature of the first temperature measuring point meets a downward trend, and record the first judgment result, wherein if the first judgment result is yes, the first adjustment strategy is defined as valid.

[0166] The risk type determination module refers to a unit for identifying potential safety risks of the induction cooker in the current running state, which can be a data processing unit integrating a temperature sensor interface, a data acquisition circuit and a microprocessor. The coil power output contribution determination module refers to a unit for analyzing the influence degree of the induction cooker coil on the leakage magnetic field of a specific area, which can be a control unit containing a position sensor interface, a power distribution algorithm and a magnetic field distribution database. The first adjustment module refers to a unit for fine control of the power output of the induction cooker coil according to a preset strategy, which can be a pulse width modulation (PWM) controller. The first judgment module refers to a unit for evaluating the effectiveness of the power adjustment strategy, which can be a temperature trend analyzer.

[0167] The scheme of the present application embodies each logical step in the induction cooker heating process control method as an independent system module. Through modular design, the system allocates risk type determination, coil power output contribution determination, first adjustment and first judgment functions to different units, so that the tongue feature recognition method can be effectively and reliably executed.

[0168] In the embodiments of the present application, it should be understood that the disclosed method and system can be implemented in other ways. The above described system embodiments are merely schematic, for example, the division of the modules is only a logical function division, and actual implementation can have another division manner, for example, a plurality of modules or components can be combined, or can be integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the displayed or discussed components can be indirect coupling or communication connection through some interfaces, devices or modules, and can be electrical, mechanical or other forms.

[0169] In addition, each functional module in each embodiment of the present application can be integrated in one processor, or each module can be a separate device, or two or more modules can be integrated in one device; each functional module in each embodiment of the present application can be realized in the form of hardware or in the form of hardware plus software functional units.

[0170] Those skilled in the art can understand that all or part of the steps of the above method embodiments can be completed by program instructions and related hardware, the above program instructions can be stored in a computer readable storage medium, and the program instructions execute the steps including the above method embodiments when executed; and the above storage medium includes a mobile storage device, a read only memory (ROM), a magnetic disc or an optical disc and various program code storage media.

[0171] Hereinafter, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Therefore, the features defined with "first" and "second" can explicitly or implicitly include one or more features.

[0172] If a flowchart is used in the present application, the flowchart is used to illustrate the operations performed by the system according to the embodiments of the present application. It should be understood that the preceding or subsequent operations are not necessarily executed in sequence. On the contrary, each step can be processed in reverse order or simultaneously. Meanwhile, other operations can be added to these processes, or one or more steps can be removed from these processes.

[0173] The above has carried out the detailed introduction to the electromagnetic stove heating process control method and system provided by the application. The above description of the disclosed embodiments enables a person skilled in the art to implement or use the application. Various modifications of these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the application. Therefore, the application will not be limited to these embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for controlling the heating process of an electromagnetic oven, applied to a scenario of partial leakage magnetic field, characterized in that, The method comprises the following steps: In a first time period, a first actual temperature of all temperature measuring points on the induction cooker panel is collected at a first frequency, an actual temperature rise rate of each temperature measuring point is calculated, and when the actual temperature rise rate of the first temperature measuring point meets a preset condition, the risk type of the induction cooker is determined; When the pot is placed off-center, pot position information is obtained, the actual power distribution of the induction cooker coil is obtained according to the pot position information, the first induction cooker coil with the largest contribution to the leakage magnetic field power output of the first temperature measuring point is determined according to the actual power distribution of the induction cooker coil and the leakage magnetic field distribution map of the induction cooker panel; According to a first adjustment strategy, the pulse width modulation duty cycle of the first induction cooker coil is modulated at a first periodic waveform amplitude at a first adjustment frequency; After the modulation is completed, a second actual temperature of the first temperature measuring point is collected at a second frequency, it is judged whether the second actual temperature of the first temperature measuring point meets a downward trend, and the first judgment result is recorded, and if the first judgment result is yes, the first adjustment strategy is defined as valid.

2. The electromagnetic induction heating process control method of claim 1, wherein, After the risk type of the first induction cooker coil and the first temperature measuring point is determined, the following steps are further included: According to a second adjustment strategy, the first power value of the first induction cooker coil is periodically transferred to a second induction cooker coil with a lower contribution to the leakage magnetic field power output within a second time period.

3. The electromagnetic induction heating process control method of claim 2, wherein, After it is judged whether the second actual temperature of the first temperature measuring point meets a downward trend and the first judgment result is recorded, the following steps are included: If the first judgment result is no, the first adjustment frequency is raised to a second adjustment frequency or the first periodic waveform amplitude is raised to a second periodic waveform amplitude; According to the first adjustment strategy, the pulse width modulation duty cycle of the first induction cooker coil is modulated at the first periodic waveform amplitude at the second adjustment frequency as a first adjustment scheme; Or, according to the first adjustment strategy, the pulse width modulation duty cycle of the first induction cooker coil is modulated at the second periodic waveform amplitude at the first adjustment frequency as a second adjustment scheme; Or, when the first adjustment scheme or the second adjustment scheme is used, the second adjustment strategy is executed in parallel.

4. The electromagnetic induction heating process control method of claim 1, wherein, The first actual temperature of all temperature measuring points on the induction cooker panel is collected at a first frequency within a first time period, the actual temperature rise rate of each temperature measuring point is calculated, and when the actual temperature rise rate of the first temperature measuring point meets a preset condition, the risk type of the induction cooker is determined, which comprises the following steps: Within a first preset period, the first actual temperature data of all the temperature measuring points is collected at the first frequency according to the thermistor sensor and the digital converter of each temperature measuring point; The actual temperature rise rate of each temperature measuring point is calculated according to a temperature rise rate formula; It is judged whether the actual temperature rise rate of the first temperature measuring point is greater than a preset metal object induced temperature rise threshold value, and the second judgment result is recorded; If the second judgment result is yes, it is defined that the induction cooker has an external metal heating risk.

5. The electromagnetic induction heating process control method of claim 1, wherein, The method comprises the following steps: When the pot is placed off-center, the pot position information is acquired by a position sensor; According to the pot position information, the actual power distribution of the electromagnetic oven coil is acquired by querying a pre-stored power distribution table or using a least square method; According to the actual power distribution of the electromagnetic oven coil and the electromagnetic oven panel leakage magnetic field distribution map, the leakage magnetic field power output contribution of all the electromagnetic oven coils to the first temperature measuring point is acquired by table lookup or weighted summation and is arranged in descending order, and the first electromagnetic oven coil with the largest leakage magnetic field power output contribution is determined. The method further comprises the following steps after it is determined that the first adjustment strategy is effective:

6. The electromagnetic induction heating process control method of claim 1, wherein, It is determined whether the second actual temperature of the first temperature measuring point decreases to below the pre-set safety temperature threshold and remains stable within a third time period; Or, it is determined whether the second actual temperature of the first temperature measuring point presents a downward trend within a fourth time period; Both of the above determinations are recorded as the first determination result, and if the first determination result is yes, it is defined that the first adjustment strategy is effective. After it is determined that the electromagnetic oven has an external metal heating risk, the method further comprises the following steps:

7. The electromagnetic induction heating process control method of claim 4, wherein, In the first mode, the third actual temperature of all the temperature measuring points is collected at a third frequency within M continuous time windows in a fourth time period; In the i-th time window, the second temperature measuring point corresponding to the highest third actual temperature is acquired, and in the i+1-th time window, the third temperature measuring point corresponding to the highest third actual temperature is acquired, and a hotspot displacement vector of the second temperature measuring point to the third temperature measuring point is calculated; In the continuous N time windows, it is determined whether the moving direction of the hotspot displacement vector is highly consistent with the moving direction of the pre-set magnetic field peak point, and the third determination result is recorded; It is determined whether the moving rate of the hotspot displacement vector is similar to the moving rate of the pre-set magnetic field peak point, and the fourth determination result is recorded; It is determined whether the third actual temperature presents a downward trend, and the fifth determination result is recorded; If the third determination result, the fourth determination result and the fifth determination result are all yes, it is defined that the first mode is invalid. After it is determined that the first mode is invalid, the method further comprises the following steps:

8. The electromagnetic induction heating process control method of claim 7, wherein, In the second mode, the instantaneous switching of the magnetic field peak value is performed in a pseudo-random sequence between multiple non-continuous pre-set magnetic field peak points. ​ In the transient switching process, it is judged whether the third actual temperature is below the preset safety temperature threshold and remains stable within a fifth time period, recorded as a sixth judgment result; If the sixth judgment result is yes, and if there is no external metal heating risk for the electromagnetic oven, the second mode is exited.

9. The electromagnetic induction heating process control method of claim 7, wherein, After the judgment of whether the actual temperature rise rate of the first temperature measurement point is greater than the preset metal object induced temperature rise threshold, recorded as a second judgment result, the following steps are further included: It is judged whether the actual temperature rise rate of a fourth temperature measurement point adjacent to the first temperature measurement point presents a high absolute value but opposite direction state, recorded as a seventh judgment result; If the second judgment result and the seventh judgment result are both yes, the first electromagnetic oven coil with the largest contribution to the leaked magnetic field power output of the first temperature measurement point is determined according to the actual power distribution of the electromagnetic oven coil and the electromagnetic oven panel leakage magnetic field distribution map; Within a sixth time period, the second power value of the first electromagnetic oven coil is reduced and then restored, an energy perturbation curve of the first electromagnetic oven coil is generated by fitting, and a fourth actual temperature of the first temperature measurement point is collected at the third frequency, and a temperature change curve of the first temperature measurement point is generated by fitting; It is judged whether the temperature change curve of the first temperature measurement point and the energy perturbation curve of the first electromagnetic oven coil present a high degree of synchronous response on the time axis of the sixth time period, recorded as an eighth judgment result; If the eighth judgment result is yes, it is defined that the first temperature measurement point has an external metal heating risk and the temperature change of the fourth temperature measurement point is caused by a non-electromagnetic event, and the first mode is entered.

10. An electromagnetic induction hob heating process control system, applied to a local leakage magnetic field scenario, characterized in that, It includes: A risk type determination module for collecting first actual temperatures of all temperature measurement points of an electromagnetic oven panel at a first frequency within a first time period, calculating actual temperature rise rates of each temperature measurement point, and determining a risk type of the electromagnetic oven when the actual temperature rise rate of the first temperature measurement point meets a preset condition; A coil power output contribution determination module for obtaining pot position information when a pot is placed off-center, obtaining actual power distribution of an electromagnetic oven coil according to the pot position information, and determining a first electromagnetic oven coil with the largest contribution to the leaked magnetic field power output of the first temperature measurement point according to the actual power distribution of the electromagnetic oven coil and the electromagnetic oven panel leakage magnetic field distribution map; A first adjustment module for modulating a pulse width modulation duty cycle of the first electromagnetic oven coil with a first periodic waveform amplitude at a first adjustment frequency according to a first adjustment strategy; A first judgment module for collecting second actual temperatures of the first temperature measurement point at a second frequency after the modulation is completed, judging whether the second actual temperatures of the first temperature measurement point meet a downward trend, recording as a first judgment result, and defining that the first adjustment strategy is effective if the first judgment result is yes.

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