Cooking device and intelligent control method thereof

Abstract

The invention discloses a cooking device and an intelligent control method thereof. The cooking device comprises a range hood with a fan and a stove arranged below the range hood. The kitchen range is an electromagnetic range and comprises a coil panel, a heating element and a heating element, and the current transformer is used for detecting the current of the coil panel so as to judge the cooking action.

Description

Technical Field

[0001] This invention relates to an oil fume purification device, and more particularly to a cooking device and an intelligent control method for the cooking device. Background Technology

[0002] Range hoods have become an indispensable kitchen appliance in modern homes. Installed above the stove, they quickly remove and exhaust the waste from the stove and the harmful fumes produced during cooking.

[0003] As users become increasingly focused on user experience, range hoods and cooktops are now paying more attention to the intelligence and automation of the cooking process. On one hand, the cooking process involves many different stages and operations, and the amount of smoke produced varies greatly at these stages. On the other hand, when purchasing a range hood, after ensuring effective smoke extraction, users are increasingly concerned about noise levels during operation. Ordinary range hoods typically offer multiple speed settings (high, medium, and low) for users to choose from, allowing them to manually adjust the speed and cooking mode to balance performance and noise levels.

[0004] To automatically adjust the fan speed based on the real-time situation of cooking fumes and thus improve the fume extraction effect, some existing smart range hoods use fume concentration sensors to detect the concentration of cooking fumes in the environment. Based on the real-time detected fume concentration value, the fan speed is automatically adjusted. For example, Chinese Patent Application No. 201510137480.0 discloses a T-shaped range hood with a multi-layer fume separation net, which includes a casing, an oil cup, a motor, a volute with a motor bracket, dual turbines, and a smoke sensor. The smoke sensor senses the amount of smoke and automatically adjusts the motor speed, thereby adjusting the suction power of the range hood.

[0005] The aforementioned existing technologies increase the rotation speed for adsorption only after the fumes have diffused, which is a delayed control method (e.g., it often takes 3-5 seconds for the fumes to reach the sensor). Large amounts of fumes are often generated instantaneously (e.g., food escapes within seconds of being added to the pan). By the time the sensor detects the fumes, they have already escaped beyond the negative pressure zone of the range hood and are difficult to re-entrain, resulting in a perceived decrease in fume extraction efficiency. The overall adjustment is not intelligent enough, leading to a poor cooking experience for the user. Furthermore, fume concentration sensors, which require direct exposure to fumes, are easily contaminated and require frequent maintenance or cleaning, further increasing after-sales costs for users. Summary of the Invention

[0006] The first technical problem to be solved by the present invention is to address the shortcomings of the prior art by providing a cooking device that actively identifies cooking actions and can achieve intelligent control with minimal delay.

[0007] The second technical problem to be solved by the present invention is to provide an intelligent control method for the above-mentioned cooking device.

[0008] The third technical problem to be solved by the present invention is to provide a real-time diagnosis and control method for the above-mentioned cooking device.

[0009] The technical solution adopted by the present invention to solve the first technical problem mentioned above is: a cooking device, comprising a range hood with a fan and a stove installed below the range hood; characterized in that:

[0010] The stove is an induction cooker, and the stove includes:

[0011] Coil disk; and

[0012] A current transformer detects the current in the coil to determine the cooking action.

[0013] By using a current transformer to detect the current in the coil, the delay is small. It can automatically identify or predict cooking actions or changes in oil fumes during the cooking process, and automatically adjust the gear according to the cooking conditions or stages, which facilitates intelligent cooking and provides a more comfortable and convenient cooking experience, improving the adaptability of the scene and the user's cooking experience.

[0014] The technical solution adopted by the present invention to solve the second technical problem mentioned above is: an intelligent control method for a cooking device, wherein the cooking device is as described above, characterized in that the intelligent control method includes the following steps:

[0015] 1) Upon powering on, the range hood and cooktop start, and the fan of the range hood operates at a preset speed;

[0016] 2) The current transformer of the stove continuously samples the current of the coil.

[0017] 3) Harmonic component extraction: The current obtained in step 2) is calculated at regular intervals using the following formula:

[0018]

[0019] The 9th and 11th harmonic components of the current in the coil were obtained respectively. ,in For harmonic order, For the first RMS value of subharmonic current For the first Instantaneous current at each sampling point This represents the number of sampling points per cycle.

[0020] 4) Action criterion generation:

[0021] Calculate the dynamic harmonic increment threshold: , and Indicates two consecutive samples, and determines and If the condition is met, proceed to step 5); otherwise, maintain the preset gear for a certain period of time and return to step 2.

[0022] 5) The stove sends an upgrade command to the range hood, and the range hood's fan operates in high-speed mode. After running for a certain period of time, it returns to step 2).

[0023] By monitoring the changes in the 9th and 11th harmonic components in the heating coil current of the induction cooker in real time, a mapping relationship between the harmonic amplification and the mechanical action of the cookware (stirring) is established. When a sudden increase in a specific harmonic component is detected (such as the 11th harmonic amplification > 5%), it is determined that the user is performing the stirring operation, and the range hood is triggered to increase its speed in advance to provide a more comfortable and convenient cooking experience, improve scene adaptability and user cooking experience.

[0024] Preferably, the cooktop includes a processor electrically connected to a current transformer, and the range hood includes a main controller. Steps 3) and 4) are calculated and determined by the cooktop's processor, and the fan speed control in step 5) is implemented by the main controller.

[0025] Preferably, in step 2), the sampling frequency .

[0026] The technical solution adopted by the present invention to solve the third technical problem mentioned above is: a real-time diagnosis and control method for a cooking device, wherein the cooking device is as described above, characterized in that the intelligent control method includes the following steps:

[0027] 1) Upon powering on, the range hood and cooktop start, and the fan of the range hood operates at a preset speed;

[0028] 2) The current transformer of the stove continuously samples the current of the coil.

[0029] 3) Harmonic component extraction: The current obtained in step 2) is calculated using the following formula:

[0030]

[0031] The 1st to 40th harmonic components of the coil current were obtained respectively. ,in For harmonic order, For the first RMS value of subharmonic current For the first Instantaneous current at each sampling point This represents the number of sampling points per cycle.

[0032] 4) Action criterion generation:

[0033] Calculate the dynamic harmonic increment threshold: , and Indicates two consecutive samples, and determines and If the condition is true, proceed to step 5); otherwise, proceed to step 6.

[0034] 5) The cooktop sends an upgrade command to the range hood, and the fan of the range hood executes the high-speed mode;

[0035] 6) Calculate the current THD: ,judge And whether the duration is 3-8 minutes or not. If it is, an alarm is triggered indicating that the coil is aging. If it is not, the range hood fan will continue to run at the preset speed, and then return to step 2).

[0036] This enables real-time online diagnosis of coil aging, providing early warnings and preventing temporary coil malfunctions from causing cooking failures, thus improving accuracy.

[0037] Preferably, the cooktop includes a processor electrically connected to a current transformer, and the range hood includes a main controller. Steps 3), 4), and 6) are calculated and determined by the cooktop's processor, and the fan speed control in step 5) is implemented by the main controller.

[0038] Preferably, in step 2), the sampling frequency .

[0039] Compared with the prior art, the advantages of the present invention are: by using a current transformer to detect the current of the coil, the delay is small, and it can automatically identify or predict the cooking action or changes in oil fumes during the cooking process, and automatically adjust the gear according to the cooking conditions or stages, which facilitates intelligent cooking, provides a more comfortable and convenient cooking experience, and improves the adaptability of the scene and the user's cooking experience. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of the cooking device after installation and use according to an embodiment of the present invention;

[0041] Figure 2 This is a block diagram illustrating the control device principle of a stove according to an embodiment of the present invention;

[0042] Figure 3 This is a schematic diagram of the control device of the range hood according to an embodiment of the present invention;

[0043] Figure 4 A schematic diagram illustrating the working principle and harmonic sources of an induction cooker;

[0044] Figure 5This is a control flowchart of the cooking apparatus according to an embodiment of the present invention;

[0045] Figure 6 This is a flowchart illustrating the real-time diagnosis of coil aging in the induction cooker of the cooking apparatus according to an embodiment of the present invention. Detailed Implementation

[0046] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0047] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Since the embodiments disclosed in this invention can be arranged in different directions, these terms indicating direction are only for illustration and should not be regarded as limitations. For example, "upper" and "lower" are not necessarily limited to directions opposite to or consistent with the direction of gravity. In addition, features defined with "first" and "second" may explicitly or implicitly include one or more of such features.

[0048] See Figure 1 The image shows a cooking appliance including a range hood 100 and a cooktop 200. The range hood 100 is positioned above the cooktop 200. The range hood 100 can be any existing type of range hood unit, such as... Figure 1 The low-suction range hood shown includes a fan frame 1, a smoke collection hood 2 connected below the fan frame 1, and a smoke baffle 3 for opening and closing the smoke inlet on the smoke collection hood 2. The fan frame 1 houses the fan (…). Figure 1 (Not shown in the image; this is existing conventional technology).

[0049] The cooktop 200 is used to place the pot 300 for cooking. The cooktop 200 is an induction cooktop; see [link / reference]. Figure 2 The stove in this embodiment of the invention also includes a processor 201, a coil 202 and a current transformer 203. The current transformer 203 is used to detect the current of the coil 202. The coil 202 and the current transformer 203 are electrically connected to the processor 201 respectively.

[0050] See Figure 3The range hood of this embodiment also includes a main controller 4, which has a processor. A fan drive module 41 (the fan is not shown and can be in any existing form and installation location) is electrically connected to the main controller 41. Furthermore, the main controller 4 may also be electrically connected to a switch module 42 and a storage module 43, which are identical to those in the prior art. Additionally, a smoke baffle drive module 44 for driving the smoke baffle 3 is also electrically connected to the main controller 4. The main controller 4 can also connect to other optional modules, such as a networking module for connecting to the Internet of Things (IoT).

[0051] See Figure 4 When the IGBT switch of the induction cooker is turned on, it oscillates at a high frequency of 20~40kHz, and the coil of coil 202 is electromagnetically coupled to the cookware 300. When the cookware 300 is suspended in the air (when flipping the food), the air gap in the magnetic circuit suddenly increases. According to the magnetic reluctance formula: Magnetic resistance : Air gap length, : Permeability If the cross-sectional area is given, then the air gap length is... Increase, making the magnetic reluctance The equivalent inductance of the coil increases sharply. decline( This makes the original resonant frequency... In order to maintain power, the IGBT switch needs to increase the switching duty cycle, which intensifies the current discontinuity during the switching process, causing high-frequency harmonic energy to accumulate in a specific frequency band.

[0052] In this invention, the 9th / 11th harmonics from the high-frequency harmonics are selected. This is because, as shown in Table 1 below:

[0053]

[0054] Table 1: Energy data obtained from each harmonic experiment

[0055] Therefore, the 9th and 11th harmonics have the following advantages: ① Sensitivity: The 9th and 11th harmonics are located in the 0.45-0.55 octave band (9kHz-11kHz) of the typical switching frequency (20kHz), which is most sensitive to inductance abrupt changes; ② Anti-interference: This band avoids power frequency harmonics (the 3rd and 5th harmonics are easily affected by power grid interference) and high-frequency noise (the >15th harmonics are severely attenuated); ③ Uniqueness: Experiments have shown that the amplification of the 11th harmonic during stir-frying is significantly higher than that of other harmonics (+5.1% vs. the 5th harmonic +1.5%).

[0056] Therefore, by monitoring the changes in the 9th and 11th harmonic components in the current of the induction cooker's coil 202 in real time, a mapping relationship between harmonic amplification and the mechanical action of the cookware (stirring) can be established. When a sudden increase in a specific harmonic component is detected (such as the 11th harmonic amplification > 5%), it is determined that the user is performing a stirring operation, and the range hood is triggered to increase its speed 0.8 to 1.5 seconds in advance. At the same time, the harmonic distortion rate (THD) is used to diagnose the aging status of the induction coil, realizing dual control through detection. The specific process will be detailed below.

[0057] See Figure 5 The cooking apparatus of the present invention includes a linkage intelligent control method comprising the following steps:

[0058] 1) Turn on the machine. The range hood 100 and the cooktop 200 will start. The fan of the range hood 100 will run at the preset level. Select whether the cooking device needs intelligent monitoring. If yes, start the intelligent mode and proceed to step 2). If no, start the manual mode and then operate manually. Alternatively, you can skip this step and proceed directly to step 2).

[0059] 2) Current transformer 203 continuously samples the current. Current transformer 203 can be a Rogowski coil, with a range of 0~50A and a bandwidth of 100kHz. The sampling point is the coil input line of the induction cooker's coil plate 202; either the L / N line is acceptable. The preferred sampling frequency is... (Satisfies Shannon's theorem, covering all 40th harmonics);

[0060] 3) Harmonic component extraction: For the current obtained in step 2), perform an FFT (corresponding to 40,000 sampling points) every certain time interval, such as 200ms, using the following formula:

[0061]

[0062] The 9th and 11th harmonic components of the coil current were obtained respectively. The parameters mentioned above are explained in Table 2 below:

[0063]

[0064] Table 2: Explanation of Parameter Symbols

[0065] 4) Action criterion generation:

[0066] Calculate the dynamic harmonic increment threshold: ;judge and Whether it is valid, among which , The preset threshold can be calibrated through multiple experiments in the laboratory beforehand. In this embodiment, The preferred value is 5, and the preferred value for b is 0.8; The range is 3.5~7. The range is 0.65 to 0.95, and these two ranges can be used as action criteria. If it indicates an accidental touch, then... This can lead to missed judgments (such as slight stirring of the wok). To distinguish between cooking actions and key indicators of heat adjustment, when a stainless steel pot is normally heated... If the value is below 0.65, it will be a misjudgment when the heat of the iron pot is turned up. If the value is set higher than 0.95, a false negative will occur. When the power is increased, the 9th and 11th harmonics increase synchronously. However, the 11th harmonic is uniquely increased when stir-frying. Using a dual-condition criterion (increase + percentage) can eliminate false triggering;

[0067] If successful, proceed to step 5); if unsuccessful, maintain the preset gear for a certain period of time and then return to step 2.

[0068] 5) The cooktop 200 sends an upgrade command to the range hood 100, which then executes the high-power suction mode and returns to step 2 after running for a certain period of time.

[0069] In the above process, steps 3) and 4) can be calculated and determined by the processor 201 of the stove 200, and the fan speed control in step 5) is implemented by the main controller 4.

[0070] Therefore, by monitoring the changes in the 9th and 11th harmonic components in the heating coil current of the induction cooker in real time, a mapping relationship between the harmonic amplification and the mechanical action of the cookware (stirring) is established. When a sudden increase in a specific harmonic component is detected (such as the 11th harmonic amplification > 5%), it is determined that the user is performing the stirring operation, and the range hood is triggered to increase its speed in advance to provide a more comfortable and convenient cooking experience, improve scene adaptability and user cooking experience.

[0071] Compared with traditional temperature detection methods, the above method is compared as shown in Table 3 below:

[0072]

[0073] Table 3: Comparison of the Harmonic Analysis-Based Method of the Present Invention with Traditional Temperature Detection Method

[0074] Furthermore, the coils of induction cookers are prone to insulation aging and core cracking due to prolonged high-temperature operation, leading to a 20-40% decrease in efficiency. Traditional methods require disassembly for inspection or rely on power reduction for diagnosis, failing to provide real-time online diagnostics. This invention utilizes the aforementioned current transformer 202 for real-time coil aging diagnosis. By tracking the time-varying characteristics of the total harmonic distortion (THD), a mapping relationship between the THD growth rate and coil insulation degradation is established. When THD > 8% is detected for 5 consecutive minutes, coil aging is determined, triggering an early warning.

[0075] For details, see Figure 6 It includes the following steps:

[0076] 1) Turn on the machine. The range hood 100 and the cooktop 200 will start. The fan of the range hood 100 will run at the preset level. Select whether the cooking device needs intelligent monitoring. If yes, start the intelligent mode and proceed to step 2). If no, start the manual mode and then operate manually. Alternatively, you can skip this step and proceed directly to step 2).

[0077] 2) The current transformer 203 continuously samples the current. The current transformer 203 can be a Rogowski coil, with a range of 0~50A and a bandwidth of 100kHz. The sampling point is the coil input line of the coil plate 202 of the induction cooker, either L or N line is acceptable. The preferred sampling frequency is fs = 200kHz (satisfying Shannon's theorem and covering the 40th harmonic).

[0078] 3) Harmonic component extraction: For the current obtained in step 2), perform an FFT (corresponding to 40,000 sampling points) every certain time interval, such as 200ms, using the following formula:

[0079]

[0080] The 1st to 40th harmonic components of the coil current were obtained respectively. The parameters are the same as above.

[0081] 4) Action criterion generation:

[0082] Calculate the dynamic harmonic increment threshold: ;judge and Whether it is valid, among which and Indicates two consecutive samples. , The preset threshold can be calibrated through multiple experiments in the laboratory beforehand. In this embodiment, The preferred value is 5, and the preferred value for b is 0.8; The range is 3.5~7. The range is 0.65 to 0.95, and these two ranges can be used as action criteria. If it indicates an accidental touch, then... This can lead to missed judgments (such as slight stirring of the wok). To distinguish between cooking actions and key indicators of heat adjustment, when a stainless steel pot is normally heated... If the value is below 0.65, it will be a misjudgment when the heat of the iron pot is turned up. If the value is set higher than 0.95, a false negative will occur. When the power is increased, the 9th and 11th harmonics increase synchronously. However, the 11th harmonic is uniquely increased when stir-frying. Using a dual-condition criterion (increase + percentage) can eliminate false triggering;

[0083] If true, proceed to step 5); if false, proceed to step 6.

[0084] 5) The cooktop 200 sends an upgrade command to the range hood 100, and the range hood 100 executes the high-level strong suction mode;

[0085] 6) Calculate the current THD: ;

[0086] Aging Criteria: ,in and The preset threshold, The preferred value is 8. The preferred range is 6.5% to 9.5%, and this range can be used as an aging criterion. This can lead to false negatives (early aging), if This will result in false alarms (power grid fluctuations). The preferred time is 3-8 minutes, and in this embodiment it is 5 minutes; it can be determined in the following way. When the appliance is set up, start the timer on stove 200;

[0087] If the aging criterion is met, the alarm coil is considered aged and the power is reduced; if not, the preset setting is maintained and the process returns to step 2.

[0088] In the above process, steps 3), 4) and 6) can be calculated and determined by the processor 201 of the stove 200, and the fan speed control in step 5) is implemented by the main controller 4.

[0089] This enables real-time online diagnosis of coil aging, providing early warnings and preventing temporary coil malfunctions from causing cooking failures. It also improves accuracy (error <3%, compared to 15% for traditional methods).

Claims

1. A cooking apparatus comprising a range hood (100) with a fan and a cooktop (200) disposed below the range hood (100); characterized in that: The stove (200) is an induction cooker, and the stove (200) includes: Coil disk (202); and A current transformer (203) detects the current in the coil (202) to determine the cooking action.

2. A method for intelligent control of a cooking device, wherein the cooking device is the cooking device as described in claim 1, characterized in that, The intelligent control method includes the following steps: 1) When the machine is turned on, the range hood (100) and the stove (200) start, and the fan of the range hood (100) runs at the preset level; 2) The current transformer (203) of the stove (200) continuously samples the current of the coil (202); 3) Harmonic component extraction: The current obtained in step 2) is calculated at regular intervals using the following formula: The 9th and 11th harmonic components of the current in the coil disk (202) were obtained respectively. ,in For harmonic order, For the first RMS value of subharmonic current For the first Instantaneous current at each sampling point This represents the number of sampling points per cycle. 4) Action criterion generation: Calculate the dynamic harmonic increment threshold: , and Indicates two consecutive samples, and determines and If the condition is met, proceed to step 5); otherwise, maintain the preset gear for a certain period of time and return to step 2. 5) The cooktop (200) sends an upgrade command to the range hood (100), and the fan of the range hood (100) operates in high-speed mode. After running for a certain period of time, it returns to step 3).

3. The intelligent control method for the cooking apparatus according to claim 2, characterized in that: The cooktop (200) includes a processor (201) electrically connected to a current transformer (203), and the range hood (100) includes a main controller (4). Steps 3) and 4) are calculated and determined by the processor (201) of the cooktop (200), and the fan speed control in step 5) is implemented by the main controller (4).

4. The intelligent control method for the cooking device according to claim 2, characterized in that: In step 2), the sampling frequency .

5. A real-time diagnostic and control method for a cooking apparatus, wherein the cooking apparatus is as described in claim 1, characterized in that, The intelligent control method includes the following steps: 1) When the machine is turned on, the range hood (100) and the stove (200) start, and the fan of the range hood (100) runs at the preset level; 2) The current transformer (203) of the stove (200) continuously samples the current of the coil (202); 3) Harmonic component extraction: The current obtained in step 2) is calculated using the following formula: The first to 40th harmonic components of the current in the coil disk (202) were obtained respectively. ,in For harmonic order, For the first RMS value of subharmonic current For the first Instantaneous current at each sampling point This represents the number of sampling points per cycle. 4) Action criterion generation: Calculate the dynamic harmonic increment threshold: , and Indicates two consecutive samples, and determines and If the condition is true, proceed to step 5); otherwise, proceed to step 6. 5) The cooktop (200) sends an upgrade command to the range hood (100), and the fan of the range hood (100) executes the high-speed mode; 6) Calculate the current THD: ,judge And whether the duration is 3-8 minutes or not, if it is, an alarm is triggered to indicate that the coil (202) is aging; if it is not, the fan of the range hood (100) will continue to operate at the preset speed, and then return to step 2).

6. The real-time diagnosis and control method for a cooking apparatus according to claim 5, characterized in that: The cooktop (200) includes a processor (201) electrically connected to a current transformer (203), and the range hood (100) includes a main controller (4). Steps 3), 4) and 6) are calculated and determined by the processor (201) of the cooktop (200), and the fan speed control in step 5) is implemented by the main controller (4).

7. The real-time diagnosis and control method for a cooking apparatus according to claim 5, characterized in that: In step 2), the sampling frequency .

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