Radio frequency defrosting control methods, radio frequency defrosting equipment and media

Abstract

This invention discloses a radio frequency (RF) defrosting control method applied to an RF defrosting device, which includes an impedance matching network. The RF defrosting control method includes: acquiring the current network impedance value of the impedance matching network; determining the current parameter value of a target parameter of the frozen food based on the current network impedance value, wherein the target parameter is at least one component parameter of the load impedance of the frozen food; determining the parameter change characteristics of the target parameter based on the current parameter value; and determining whether to terminate the RF defrosting of the frozen food based on whether the parameter change characteristics conform to the change characteristics of the target temperature range. This invention solves the technical problem of low intelligence in RF defrosting devices and inaccurate control of defrosting time for frozen food.

Description

Technical Field

[0001] This invention belongs to the field of radio frequency defrosting technology, and particularly relates to a radio frequency defrosting control method, radio frequency defrosting equipment and medium. Background Technology

[0002] Radio frequency (RF) heating technology offers significant advantages over other defrosting technologies in terms of defrosting effectiveness, solving the problems of poor defrosting quality in microwave ovens and long defrosting times in refrigerators, thus meeting users' needs for rapid defrosting for nutritional purposes. The initial temperature, type, size, shape, and placement of food all affect the defrosting time of RF defrosting. Therefore, relying on users to accurately determine the defrosting time for frozen food leads to a lower level of intelligence in RF defrosting equipment and inaccurate defrosting time measurements. Summary of the Invention

[0003] This invention provides a radio frequency (RF) defrosting control method, RF defrosting equipment, and medium to solve the technical problem of low intelligence level of RF defrosting equipment and inaccurate control of defrosting time for frozen food.

[0004] In a first aspect of the invention, a radio frequency (RF) defrosting control method is provided, applied to an RF defrosting device, the RF defrosting device including an impedance matching network, the RF defrosting control method comprising: acquiring the current network impedance value of the impedance matching network; determining the current parameter value of a target parameter of frozen food based on the current network impedance value, the target parameter being at least one component parameter of the load impedance of the frozen food; determining the parameter change characteristics of the target parameter based on the current parameter value, and determining whether to terminate the RF defrosting of the frozen food based on whether the parameter change characteristics conform to the change characteristics of a target temperature range.

[0005] In conjunction with the first aspect, in some embodiments, before obtaining the current network impedance value of the impedance matching network, the method further includes: during the radio frequency defrosting process of the radio frequency defrosting device on the frozen food, detecting whether the network impedance of the radio frequency defrosting device is mismatched with the load impedance of the frozen food; if mismatched, controlling the impedance matching network to perform impedance matching so that the network impedance of the impedance matching network is rematched with the load impedance of the frozen food; and when the network impedance of the impedance matching network is rematched with the load impedance of the frozen food, performing the step of obtaining the current network impedance value of the impedance matching network.

[0006] In conjunction with the first aspect, in some embodiments, obtaining the current network impedance value of the impedance matching network includes: obtaining the switching state of each switching element in the impedance matching network, wherein the impedance matching network includes multiple variable capacitor combinations, each variable capacitor combination is a parallel connection of multiple controllable capacitors, and each controllable capacitor is a series connection of a capacitor element and a switching element; and determining the current network impedance value of the impedance matching network based on the switching state of each switching element in the impedance matching network.

[0007] In conjunction with the first aspect, in some embodiments, determining the current parameter value of the target parameter of the frozen food based on the current network impedance value includes: determining the current load impedance value of the frozen food based on the current network impedance value of the impedance matching network; and obtaining the current parameter value of the target parameter from the current load impedance value.

[0008] In conjunction with the first aspect, in some embodiments, obtaining the current parameter value of the target parameter from the current load impedance value includes: obtaining the real part value and / or the imaginary part value from the current load impedance value as the current parameter value of the target parameter.

[0009] In conjunction with the first aspect, in some embodiments, determining the parameter change characteristics of the target parameter based on the current parameter value includes: determining the current change characteristics of the real part of the load impedance of the frozen food based on the real part value of the current load impedance value and the real part value of the historical load impedance value of the frozen food; and / or determining the current change characteristics of the imaginary part of the load impedance of the frozen food based on the imaginary part value of the current load impedance value and the imaginary part value of the historical load impedance value of the frozen food.

[0010] In conjunction with the first aspect, in some embodiments, the parameter change characteristics include the current change characteristics of the real part of the load impedance. The step of determining whether to end the radio frequency defrosting of the frozen food based on whether the parameter change characteristics conform to the change characteristics of a target temperature range includes: determining whether the current change characteristics of the real part of the load impedance conform to a first target characteristic, where the first target characteristic is the change characteristics of the real part of the load impedance within a target temperature range, and the target temperature range is the temperature range required to end defrosting; if the current change characteristics of the real part of the load impedance conform to the first target characteristic, the radio frequency defrosting of the frozen food is ended.

[0011] In conjunction with the first aspect, in some embodiments, the current change characteristic of the real part of the load impedance includes the current rate of change and / or the current acceleration of change of the real part of the load impedance; determining whether the current change characteristic of the real part of the load impedance conforms to the first target characteristic includes: determining whether the difference between the current rate of change of the real part of the load impedance and the historical rate of change is greater than a first preset threshold, and / or determining whether the direction of the current acceleration of change of the real part of the load impedance relative to the historical acceleration of change has changed; when any one of the determination results is yes, it is determined that the current change characteristic of the real part of the load impedance conforms to the first target characteristic.

[0012] In conjunction with the first aspect, in some embodiments, the parameter change characteristics include the current change characteristics of the imaginary part of the load impedance. The step of determining whether to end the radio frequency defrosting of the frozen food based on whether the parameter change characteristics conform to the change characteristics of the target temperature range includes: determining whether the current change characteristics of the imaginary part of the load impedance conform to a second target characteristic, where the second target characteristic is the change characteristics of the imaginary part of the load impedance within a target temperature range, and the target temperature range is the temperature range required to end defrosting; if the current change characteristics of the imaginary part of the load impedance conform to the second target characteristic, the radio frequency defrosting of the frozen food is ended.

[0013] In conjunction with the first aspect, in some embodiments, the current change characteristics of the imaginary part of the load impedance include the current rate of change and / or the current acceleration of change of the imaginary part of the load impedance; the step of determining whether the current change characteristics of the imaginary part of the load impedance meet the second target characteristic includes: determining whether the difference between the current rate of change of the imaginary part of the load impedance and the historical rate of change is greater than a second preset threshold; and / or determining whether the direction of the current acceleration of change of the imaginary part of the load impedance relative to the historical acceleration of change has changed; when any one of the determination results is yes, it is determined that the current change characteristics of the imaginary part of the load impedance meet the second target characteristic.

[0014] In a second aspect of the invention, a radio frequency (RF) defrosting control device is provided, applied to an RF defrosting apparatus, the RF defrosting apparatus including an impedance matching network, the RF defrosting control device including: an impedance acquisition unit, configured to acquire the current network impedance value of the impedance matching network; a parameter determination unit, configured to determine the current parameter value of a target parameter of frozen food based on the current network impedance value, the target parameter being at least one component parameter of the load impedance of the frozen food; and an end judgment unit, configured to determine the parameter change characteristics of the target parameter based on the current parameter value, and determine whether to end the RF defrosting of the frozen food based on whether the parameter change characteristics conform to the change characteristics of a target temperature range.

[0015] In a third aspect of the invention, a radio frequency defrosting device is provided, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the steps of the radio frequency defrosting control method described in any embodiment of the first aspect.

[0016] In a fourth aspect of the invention, a computer-readable storage medium is provided having a computer program stored thereon that, when executed by a processor, implements the steps of the radio frequency defrosting control method described in any embodiment of the first aspect.

[0017] The one or more technical solutions provided in the embodiments of the present invention achieve at least the following technical effects or advantages:

[0018] The system acquires the current network impedance value of the impedance matching network; determines the current parameter value of the target parameter in the current load impedance value of the frozen food based on the current network impedance value; determines the parameter change characteristics of the target parameter based on the current parameter value, and determines whether to end the radio frequency defrosting of the frozen food based on whether the parameter change characteristics conform to the change characteristics of the target temperature range. This achieves automatic and accurate determination of whether defrosting needs to be ended, without relying on unpredictable information such as the initial temperature, type, size, and location of the frozen food, nor on the user's judgment of the required defrosting time. Instead, it relies on the electromagnetic characteristics of the frozen food to determine whether it has defrosted to the specified temperature range, and then determines whether to end the defrosting. This makes the control of the defrosting time of frozen food more precise, intelligent, and convenient for users to perform defrosting operations. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 A schematic diagram of the structure of the radio frequency defrosting device in some embodiments of the present invention is shown;

[0021] Figure 2 A flowchart of a radio frequency defrosting control method according to some embodiments of the present invention is shown;

[0022] Figure 3a It shows Figure 1 A schematic diagram of the circuit structure of the impedance matching network.

[0023] Figure 3b It shows Figure 3a A schematic diagram of the circuit structure of the variable capacitor combination;

[0024] Figure 4a The effect of changes in the equivalent conductivity of food ingredients on load impedance is shown.

[0025] Figure 4b This demonstrates the effect of changes in the dielectric constant of food on the load impedance;

[0026] Figure 4c The control logic of the radio frequency defrosting control method in some embodiments of the present invention is shown;

[0027] Figure 5 A functional block diagram of the radio frequency defrosting control device in some embodiments of the present invention is shown;

[0028] Figure 6 A schematic diagram of the structure of a radio frequency defrosting device in some embodiments of the present invention is shown. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0030] Furthermore, in this invention, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this invention.

[0031] Figure 1 Schematic diagrams of radio frequency (RF) defrosting devices in some embodiments of the present invention are shown. Embodiments of the present invention provide an RF defrosting control method applied to an RF defrosting device, which can be a standalone device or installed inside a refrigerator. Figure 1As shown, the radio frequency (RF) defrosting device includes a power supply module, an RF power amplifier module, and a tuning module. The tuning module includes an impedance matching network. The power supply module supplies power to the RF power amplifier module, which amplifies the signal source and outputs RF power. Because the temperature change of the frozen food during defrosting causes a change in the load impedance, an impedance matching network is needed to perform impedance matching based on the load impedance change of the frozen food, ensuring that the RF power output from the RF power amplifier module can be effectively delivered to the frozen food.

[0032] Figure 2 A flowchart of a radio frequency defrosting control method according to some embodiments of the present invention is shown. For example... Figure 2 As shown, the radio frequency defrosting control method provided in this embodiment of the invention includes the following steps S101 to S103:

[0033] In step S101: Obtain the current network impedance value of the impedance matching network.

[0034] In some embodiments, to reduce computational resources, the current network impedance value of the impedance matching network is obtained only after each successful impedance matching operation.

[0035] In some embodiments, during the radio frequency defrosting of frozen food by the radio frequency defrosting device, a mismatch is detected between the network impedance of the impedance matching network and the load impedance of the frozen food. If a mismatch is detected, the impedance matching network is controlled to perform impedance matching so that the network impedance of the impedance matching network is rematched with the load impedance of the frozen food. Once the network impedance of the impedance matching network is rematched with the load impedance of the frozen food, the current network impedance value of the impedance matching network is obtained.

[0036] When the load impedance and network impedance are mismatched, some energy will be reflected; this phenomenon is called mismatch. Mismatch leads to reduced energy transmission efficiency, increases losses in RF defrosting equipment, and may affect the performance and reliability of the equipment.

[0037] In some embodiments, detecting whether the network impedance of the impedance matching network is mismatched with the load impedance of the frozen food may include: detecting the reflection coefficient during the thawing process of the frozen food by the radio frequency defrosting device. This means that the reflection coefficient is continuously detected at a preset detection frequency during the thawing process; and determining whether the network impedance of the impedance matching network is mismatched with the load impedance of the frozen food based on the magnitude of the reflection coefficient. The reflection coefficient is an important parameter for evaluating the degree of mismatch in the radio frequency defrosting device, and can be defined as the ratio of the radio frequency signal provided by the radio frequency defrosting device to the frozen food to the radio frequency signal reflected back by the frozen food after receiving the radio frequency signal provided by the radio frequency defrosting device.

[0038] In some embodiments, in response to a trigger signal to start the current defrosting, an initial impedance matching is performed through an impedance matching network to match the network impedance of the impedance matching network with the load impedance of the frozen food. After successful initial impedance matching, the radio frequency defrosting device begins radio frequency defrosting of the frozen food. During the radio frequency defrosting process, the impedance matching network is checked for mismatch between the network impedance of the impedance matching network and the load impedance of the frozen food. After each mismatch is detected, the impedance matching network is controlled to perform impedance matching to rematch the network impedance of the impedance matching network with the load impedance of the frozen food. After the impedance matching network rematches the load impedance of the frozen food, the current network impedance value of the impedance matching network is obtained.

[0039] In some embodiments, the impedance matching network includes a combination of multiple variable capacitors. Figure 3a It shows Figure 1 A schematic diagram of the circuit structure of the impedance matching network. Figure 3b It shows Figure 3a A schematic diagram of the circuit structure of the variable capacitor combination. (Example) Figure 3a The diagram shows a feasible impedance matching network, consisting of variable capacitor combination 1, variable capacitor combination 2, and inductor 3. Figure 3a The number 4 in the diagram represents the load impedance. For example... Figure 3b As shown, each variable capacitor combination 1 and 2 is a parallel structure of multiple controllable capacitors 6, and each controllable capacitor 6 is a series connection of capacitor element 61 and switching element 62.

[0040] In some embodiments, the switching states of each switching element in the impedance matching network are obtained, and the current network impedance value of the impedance matching network is determined based on the switching states of each switching element in the impedance matching network. For example, the current network impedance value of the impedance matching network is calculated based on the switching states of each switching element in variable capacitor combination 1 and variable capacitor combination 2.

[0041] In step S102: Determine the current parameter value of the target parameter of the frozen food based on the current network impedance value. The target parameter is at least one component parameter of the load impedance of the frozen food.

[0042] In some embodiments, the current load impedance value of the frozen food is determined based on the current network impedance value of the impedance matching network; the current parameter value of the target parameter is obtained from the current load impedance value. It is understood that if the target parameter is the real part and / or imaginary part of the load impedance of the frozen food, then the current parameter value of the target parameter is at least one of the real part value and the imaginary part value of the current load impedance value of the frozen food. In some embodiments, the real part value and / or imaginary part value are obtained from the current load impedance value as the current parameter value of the target parameter.

[0043] When the impedance matching network impedance is matched to the load impedance of the frozen food, the load impedance of the frozen food and the impedance matching network impedance satisfy a complex conjugate relationship. Therefore, the current load impedance value of the frozen food can be deduced from the current network impedance value of the impedance matching network. It should be understood that if the current network impedance value is a+jb, the current load impedance value is a-jb, and they are complex conjugates. In the impedance matching network, the real part 'a' represents the resistive portion of the impedance, jb represents the reactive portion, the imaginary part 'b' represents the reactance, and j is the imaginary unit. By adjusting the values ​​of the inductance and capacitance in the impedance matching network, the real and imaginary parts of the network impedance can be changed accordingly, thus achieving impedance matching between the network and load impedances. The load impedance of the frozen food can be accurately and quickly obtained based on the complex conjugate relationship between the network impedance and the load impedance, without the need for direct detection of the load impedance of the frozen food.

[0044] Step S103: Determine the parameter change characteristics of the target parameter based on the current parameter value of the target parameter, and determine whether to end the radio frequency defrosting of the frozen food based on whether the parameter change characteristics conform to the change characteristics of the target temperature range.

[0045] In some embodiments, the parameter change characteristics of the target parameter include the current change characteristics of the real part of the load impedance of the frozen food and / or the current change characteristics of the imaginary part of the load impedance. The current change characteristics of the real part are the characteristics exhibited by the real part of the load impedance as it changes with thawing time, and the current change characteristics of the imaginary part are the characteristics exhibited by the imaginary part of the load impedance as it changes with thawing time.

[0046] It should be noted that frozen food, as a mixture, will have its dielectric properties (including equivalent conductivity and dielectric constant) affected by temperature changes, assuming a constant loss tangent. The loss tangent describes the degree of energy loss through the medium. Furthermore, during the thawing process, the equivalent conductivity, dielectric constant, and other dielectric properties do not change uniformly with temperature but exhibit different characteristics across different temperature ranges. These changes in dielectric properties affect the load impedance of the frozen food. Therefore, during the thawing process, the load impedance exhibits different characteristics across different temperature ranges. The specific temperature range to which the food has thawed can be determined based on these characteristics.

[0047] The magnitude of the load impedance is related to the type, size, location, and temperature of the food. The type, size, and location of the food determine the initial value of the load impedance, while the equivalent conductivity and dielectric constant corresponding to the temperature change during the thawing process determine the trend of the load impedance during subsequent temperature rise. Since the equivalent conductivity and dielectric constant do not change uniformly with temperature increase, the characteristics of the change in equivalent conductivity and dielectric constant differ across different temperature ranges during the temperature rise of frozen food. This results in different characteristics for the change of the real and imaginary parts of the load impedance across different temperature ranges. Therefore, the decision to terminate radio frequency thawing can be made based on whether the characteristics of the change of the real and / or imaginary parts of the load impedance conform to the characteristics of the target temperature range.

[0048] To illustrate the validity of this conclusion, the possible ranges of variation in the equivalent conductivity and dielectric constant of frozen food were selected, and a modeling simulation was performed on food of a certain size and shape to obtain... Figure 4a and Figure 4b The results are shown. Figure 4a The effect of changes in the equivalent conductivity of food ingredients on load impedance is shown. Figure 4b This illustrates the effect of changes in the dielectric constant of food materials on the load impedance.

[0049] Depend on Figure 4a It can be seen that, within the range of equivalent conductivity, the variation range of the real part is much larger than that of the imaginary part. This comparison becomes clearly apparent when the real and imaginary parts are taken on similar proportional axes. Figure 4b It can be seen that within the range of dielectric constant values, the range of variation of the imaginary part is much larger than that of the real part; when the real and imaginary parts take similar proportional axes, the above comparison relationship can be clearly seen.

[0050] In some embodiments, determining parameter change characteristics based on the current parameter value of the target parameter includes: determining the current change characteristics of the real part of the load impedance of the frozen food based on the real part value of the current load impedance value and the real part value of the historical load impedance value of the frozen food.

[0051] When the parameter change characteristics include the current change characteristics of the real part of the load impedance, determining whether to end the radio frequency defrosting of the frozen food based on the parameter change characteristics may include: determining whether the current change characteristics of the real part of the load impedance meet the first target characteristic, the first target characteristic being the change characteristics of the real part of the load impedance of the frozen food in the target temperature range, the target temperature range being the temperature range required to end defrosting; if the current change characteristics of the real part of the load impedance meet the first target characteristic, it indicates that the temperature inside the frozen food has risen to the target temperature range, and the radio frequency defrosting of the frozen food ends.

[0052] It should be understood that the current change characteristics of the real part of the load impedance include the current rate of change and / or the current acceleration of change of the real part of the load impedance. In some embodiments, curve fitting is performed based on the real part values ​​of multiple acquired load impedance values ​​to obtain a fitted curve of the change of the real part of the load impedance of the frozen food over time. The first derivative is calculated based on the fitted curve to obtain the current rate of change of the real part of the load impedance of the frozen food, and the second derivative is calculated based on the fitted curve to obtain the current acceleration of change of the real part of the load impedance of the frozen food.

[0053] It should be understood that the target temperature range can be a user-specified temperature range or a pre-set fixed temperature range, such as near zero degrees Celsius. In some embodiments, it is necessary to thaw frozen food to near zero degrees Celsius, and the target temperature range is a temperature range that includes zero degrees Celsius and meets a preset size. For example, the target temperature range can be set to -2°C to 2°C, or -1°C to 1°C, or -3°C to 3°C, and so on.

[0054] It should be understood that when frozen food thaws to near zero degrees Celsius, the morphology of the ice crystals begins to change, causing the rate of change of the load impedance to suddenly accelerate. For some types of frozen food, the dielectric properties of the load impedance even exhibit an inflection point near zero degrees Celsius, resulting in inflection points in both the real and imaginary parts of the load impedance. Therefore, when frozen food is thawed to near zero degrees Celsius, the real and imaginary parts of the load impedance exhibit unique changing characteristics (an accelerated rate of change or the appearance of an inflection point).

[0055] In some embodiments, the current change characteristic of the real part in the load impedance can be determined by using the historical rate of change of the real part, including: determining whether the difference between the current rate of change of the real part in the load impedance and the historical rate of change of the real part is greater than a first preset threshold, and / or; determining whether the direction of the current change acceleration of the real part in the load impedance relative to the historical change acceleration of the real part has changed; and determining that the current change characteristic of the real part in the load impedance conforms to the first target characteristic when any one of the determination results is yes.

[0056] It should be noted that if the difference between the current rate of change of the real part of the load impedance and the historical rate of change of the real part is greater than the first preset threshold, it indicates that the rate of change of the real part of the load impedance has suddenly accelerated, which means that the frozen food has thawed to near zero degrees Celsius. If the direction of the current acceleration of the real part of the load impedance changes relative to the historical acceleration of the real part, it indicates that the real part has reached an inflection point, which also means that the frozen food has thawed to near zero degrees Celsius.

[0057] It is understandable that the historical rate of change of the real part can be the rate of change of the real part of the load impedance of frozen food obtained by curve fitting based on the real part values ​​of multiple load impedance values ​​obtained after the last successful impedance matching by the impedance matching network, and by calculating the first derivative based on the fitted curve.

[0058] In other embodiments, determining whether the current change characteristic of the real part of the load impedance matches the first target characteristic does not require relying on the historical rate of change of the real part. Instead, it involves: pre-measuring the change characteristic of the real part of the load impedance within a target temperature range during the thawing process of various food items to obtain multiple reference change characteristics corresponding to each food item; before or at the start of the current thawing, obtaining the type of the frozen food item to be thawed, and determining the first target characteristic from the multiple reference change characteristics based on the type of frozen food item, and determining whether the current change characteristic of the real part of the load impedance matches the first target characteristic during the current thawing process. The type of frozen food item can be input by the user or obtained through image recognition.

[0059] In other embodiments, determining parameter change characteristics based on the current parameter value of the target parameter includes: determining the current change characteristics of the imaginary part of the load impedance of the frozen food based on the imaginary part value in the current load impedance value and the imaginary part value in the historical load impedance value of the frozen food.

[0060] When the parameter change characteristics include the current change characteristics of the imaginary part of the load impedance, determining whether to end the radio frequency defrosting of the frozen food based on the parameter change characteristics may include: determining whether the current change characteristics of the imaginary part of the load impedance meet the second target characteristic, the second target characteristic being the change characteristics of the frozen food in the target temperature range, the target temperature range being the temperature range required to defrost the frozen food; if the current change characteristics of the imaginary part of the load impedance meet the second target characteristic, the radio frequency defrosting of the frozen food is ended.

[0061] In some embodiments, determining whether the current change characteristic of the imaginary part in the load impedance conforms to the second target characteristic by means of the historical change rate of the imaginary part may include: determining whether the difference between the current change rate of the imaginary part in the load impedance and the historical change rate of the imaginary part is greater than a second preset threshold; and / or determining whether the direction of the current change acceleration of the imaginary part in the load impedance relative to the historical change acceleration of the imaginary part has changed; and when any one of the determination results is yes, determining that the current change characteristic of the imaginary part in the load impedance conforms to the second target characteristic.

[0062] It is understandable that the historical rate of change of the imaginary part can be obtained by fitting the imaginary part of the load impedance of frozen food to a curve after the previous impedance matching network successfully performed impedance matching, and then calculating the first derivative based on the fitted curve.

[0063] It should be understood that the current change characteristics of the imaginary part of the load impedance include the current rate of change and the current acceleration of change of the imaginary part of the load impedance. In some embodiments, curve fitting is performed based on the imaginary part values ​​of the load impedance obtained multiple times to obtain a fitted curve of the change of the imaginary part of the load impedance of frozen food over time, and the first derivative and the second derivative are calculated based on the fitted curve to obtain the current rate of change and the current acceleration of change of the imaginary part of the load impedance.

[0064] It should be noted that the load impedance values ​​obtained multiple times mentioned above include the current load impedance value and multiple historical load impedance values. Each historical load impedance value is the load impedance value obtained after each successful impedance matching operation by the impedance matching network within a historical time window.

[0065] In other embodiments, determining whether the current change characteristic of the imaginary part of the load impedance matches the second target characteristic does not require relying on the historical rate of change of the imaginary part. This includes: pre-measuring the change characteristic of the imaginary part of the load impedance within a target temperature range during the thawing process of various foods to obtain multiple reference change characteristics corresponding to each food; before or at the start of the current thawing, obtaining the type of the frozen food to be thawed, and determining the second target characteristic from the multiple reference change characteristics based on the type of the frozen food, and determining whether the current change characteristic of the imaginary part of the load impedance matches the second target characteristic during the current thawing process. The type of frozen food can be input by the user or obtained through image recognition.

[0066] In some other embodiments, the current parameter value of the target parameter is the real part and the imaginary part of the current load impedance value. Determining whether to end the radio frequency defrosting of the frozen food based on whether the parameter change characteristics meet the change characteristics of the target temperature range may include: determining whether the current change characteristics of the real part of the load impedance meet the first target characteristic, and determining whether the current change characteristics of the imaginary part of the load impedance meet the second target characteristic. If the current change characteristics of the real part of the load impedance meet the second target characteristic or whether the current change characteristics of the imaginary part of the load impedance meet the second target characteristic, it indicates that the frozen food has been defrosted to the point that the temperature of the frozen food has reached the target temperature range, and then the radio frequency defrosting of the frozen food is ended.

[0067] Figure 4c The control logic of the radio frequency defrosting control method in some embodiments of the present invention is illustrated. To facilitate understanding of the radio frequency defrosting control method provided in the embodiments of the present invention, the following references are made. Figure 4c One control logic of the radio frequency defrosting control method in this embodiment of the invention is given as follows:

[0068] Step S1: The radio frequency defrosting device receives the trigger signal to start radio frequency defrosting, and the impedance matching network performs initial matching between the network impedance and the load impedance of the frozen food.

[0069] Step S2: Detect the reflection coefficient of the frozen food during the radio frequency defrosting process using the radio frequency defrosting equipment;

[0070] Step S3: Determine whether the network impedance and load impedance are mismatched based on the reflection coefficient. If so, proceed to step S4.

[0071] Step S4: The impedance matching network performs impedance matching to match the network impedance with the load impedance of the frozen food, then proceeds to step S5;

[0072] Step S5: Based on the complex conjugate relationship between network impedance and load impedance, and the current network impedance value of the impedance matching network, determine the real part (or imaginary part) of the current load impedance value of the frozen food.

[0073] Step S6: Based on the real (or imaginary) part values ​​of the load impedance obtained in the previous and current iterations, perform cumulative calculations to obtain the first and / or second derivatives of the real (or imaginary) part of the load impedance with time.

[0074] Step S7: Determine whether the first and / or second derivatives of the real (or imaginary) part of the load impedance with time satisfy the characteristics of the target temperature range to which thawing is required. If yes, proceed to step S7.

[0075] Step S8: End the radio frequency defrosting of frozen food.

[0076] The radio frequency (RF) defrosting control method provided in this invention relies on whether the changing characteristics of the real and / or imaginary parts of the load impedance match the changing characteristics of the target temperature range to determine the current temperature of the frozen food, thereby determining whether RF defrosting needs to be terminated. Because it relies on the changing characteristics of the real and / or imaginary parts of the load impedance, it does not depend on the shape or size of the drawer in the RF defrosting device, nor on unpredictable initial information such as the type, size, shape, position, or initial temperature of the food. Therefore, it exhibits strong independence and stability in determining the temperature of the frozen food during RF defrosting, effectively facilitating user defrosting operations, accurately determining the food temperature, and thus precisely controlling the duration and end time of RF defrosting.

[0077] Based on the same inventive concept, embodiments of the present invention provide a radio frequency defrosting control device, which is applied to a radio frequency defrosting device, the radio frequency defrosting device including an impedance matching network. Figure 5 A functional block diagram of the radio frequency defrosting control device in some embodiments of the present invention is shown. For example... Figure 5 As shown, the radio frequency defrosting control device includes: an impedance acquisition unit 501, used to acquire the current network impedance value of the impedance matching network; a parameter determination unit 502, used to determine the current parameter value of the target parameter of the frozen food according to the current network impedance value, wherein the target parameter is at least one component parameter of the load impedance of the frozen food; and an end judgment unit 503, used to determine the parameter change characteristics of the target parameter according to the current parameter value, and to determine whether to end the radio frequency defrosting of the frozen food according to whether the parameter change characteristics conform to the change characteristics of the target temperature range.

[0078] In some embodiments, the radio frequency defrosting control device further includes a matching control unit, configured to detect whether the network impedance of the radio frequency defrosting device is mismatched with the load impedance of the frozen food during the radio frequency defrosting process of the radio frequency defrosting device on the frozen food; if mismatched, control the impedance matching network to perform impedance matching so that the network impedance of the impedance matching network is rematched with the load impedance of the frozen food; and if the network impedance of the impedance matching network is rematched with the load impedance of the frozen food, execute the step of obtaining the current network impedance value of the impedance matching network.

[0079] In some embodiments, the impedance acquisition unit includes: a state acquisition subunit, configured to acquire the switching state of each switching element in the impedance matching network, wherein the impedance matching network includes multiple variable capacitor combinations, each variable capacitor combination is a parallel connection of multiple controllable capacitors, and each controllable capacitor is a series connection of a capacitor element and a switching element; and an impedance determination subunit, configured to determine the current network impedance value of the impedance matching network based on the switching state of each switching element in the impedance matching network.

[0080] In some embodiments, the parameter determination unit 502 includes: a determination subunit, configured to determine the current load impedance value of the frozen food based on the current network impedance value of the impedance matching network; and an acquisition subunit, configured to acquire the current parameter value of the target parameter from the current load impedance value.

[0081] In some embodiments, the acquisition subunit is used to: acquire the real part value and / or the imaginary part value from the current load impedance value, as the current parameter value of the target parameter.

[0082] In some embodiments, the termination determination unit 503 includes: a first feature extraction subunit and / or a second feature extraction subunit. The first feature extraction subunit is used to determine the current change characteristics of the real part of the load impedance of the frozen food based on the real part value in the current load impedance value and the real part value in the historical load impedance value of the frozen food. Based on the imaginary part value in the current load impedance value, the second feature extraction subunit uses the imaginary part value in the historical load impedance value of the frozen food to determine the current change characteristics of the imaginary part of the load impedance of the frozen food.

[0083] In some embodiments, the parameter change characteristics include the current change characteristics of the real part of the load impedance. The termination judgment unit 503 further includes: a first judgment execution subunit, used to determine whether the current change characteristics of the real part of the load impedance meet a first target characteristic, the first target characteristic being the change characteristics of the real part of the load impedance within a target temperature range, the target temperature range being the temperature range required to end thawing; and a first termination control subunit, used to terminate the radio frequency thawing of the frozen food if the current change characteristics of the real part of the load impedance meet the first target characteristic.

[0084] In some embodiments, the current change characteristic of the real part of the load impedance includes the current rate of change and / or the current acceleration of change of the real part of the load impedance; the first judgment execution subunit is configured to: determine whether the difference between the current rate of change of the real part of the load impedance and the historical rate of change is greater than a first preset threshold, and / or determine whether the direction of the current acceleration of change of the real part of the load impedance relative to the historical acceleration of change has changed; when either judgment result is yes, it is determined that the current change characteristic of the real part of the load impedance conforms to the first target characteristic.

[0085] In some embodiments, the parameter change characteristics include the current change characteristics of the imaginary part of the load impedance. The termination judgment unit 503 further includes: a second judgment execution subunit, used to determine whether the current change characteristics of the imaginary part of the load impedance meet the second target characteristic, the second target characteristic being the change characteristics of the imaginary part of the load impedance in a target temperature range, the target temperature range being the temperature range required to end the thawing; and a second termination execution subunit, used to terminate the radio frequency thawing of the frozen food if the current change characteristics of the imaginary part of the load impedance meet the second target characteristic.

[0086] In some embodiments, the current change characteristics of the imaginary part of the load impedance include the current rate of change and / or the current acceleration of change of the imaginary part of the load impedance; the second judgment execution subunit is configured to: determine whether the difference between the current rate of change of the imaginary part of the load impedance and the historical rate of change is greater than a second preset threshold; and / or determine whether the direction of the current acceleration of change of the imaginary part of the load impedance relative to the historical acceleration of change has changed; when any judgment result is yes, determine that the current change characteristics of the imaginary part of the load impedance conform to the second target characteristic.

[0087] Figure 6 A schematic diagram of the structure of a radio frequency defrosting device according to some embodiments of the present invention is shown. For example... Figure 6As shown, this embodiment of the invention provides a radio frequency defrosting device, including a memory 604, a processor 602, and a computer program stored in the memory 604 and executable on the processor 602. When the processor 602 executes the program, it implements the steps of the radio frequency defrosting control method described in any of the above embodiments.

[0088] Among them, Figure 6 In this document, a bus architecture (represented by bus 600) is used. Bus 600 may include any number of interconnected buses and bridges, linking various circuits including one or more processors represented by processor 602 and memory represented by memory 604. Bus 600 may also link various other circuits such as peripheral devices, voltage regulators, and power management circuits, which are well known in the art and therefore will not be described further herein. Bus interface 605 provides an interface between bus 600 and receiver 601 and transmitter 603. Receiver 601 and transmitter 603 may be the same element, i.e., a transceiver, providing a unit for communicating with various other devices over a transmission medium. Processor 602 is responsible for managing bus 600 and general processing, while memory 604 can be used to store data used by processor 602 during operation.

[0089] Based on the same inventive concept, embodiments of the present invention also provide a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the radio frequency defrosting control method described in any of the above embodiments.

[0090] According to the embodiments of the present invention, a radio frequency (RF) defrosting control method, RF defrosting device, and medium are provided. The method obtains the current network impedance value of the impedance matching network; determines the current parameter value of the target parameter in the current load impedance value of the frozen food based on the current network impedance value; determines the parameter change characteristics of the target parameter based on the current parameter value; and determines whether to end the RF defrosting of the frozen food based on whether the parameter change characteristics conform to the change characteristics of the target temperature range. This achieves automatic and accurate determination of whether defrosting needs to be ended, without relying on unpredictable information such as the initial temperature, type, size, or location of the frozen food, nor on the user's judgment of the required defrosting time. Instead, it relies on the electromagnetic properties of the frozen food to determine whether it has defrosted to the specified temperature range, and then determines whether to end the defrosting. This enables more precise and intelligent control of the defrosting time of frozen food, making defrosting operations more convenient for users.

[0091] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 Devices that specify the functions in one or more boxes.

[0092] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including an instruction device, which is implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0093] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0094] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0095] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

[0096] The above description is merely an embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of the claims of the present invention.

Claims

1. A radio frequency defrosting control method, characterized in that, The method is applied to a radio frequency (RF) defrosting device, which includes an impedance matching network, and the RF defrosting control method includes: Obtain the current network impedance value of the impedance matching network; The current parameter value of the target parameter of the frozen food is determined based on the current network impedance value, wherein the target parameter is at least one component parameter of the load impedance of the frozen food. The parameter change characteristics of the target parameter are determined based on the current parameter value, and the radio frequency defrosting of the frozen food is terminated based on whether the parameter change characteristics conform to the change characteristics of the target temperature range.

2. The radio frequency defrosting control method as described in claim 1, characterized in that, Before obtaining the current network impedance value of the impedance matching network, the method further includes: During the radio frequency defrosting process of the frozen food by the radio frequency defrosting device, it is detected whether there is a mismatch between the network impedance of the radio frequency defrosting device and the load impedance of the frozen food. If a mismatch occurs, the impedance matching network is controlled to perform impedance matching so that the network impedance of the impedance matching network is rematched with the load impedance of the frozen food. When the network impedance of the impedance matching network is rematched with the load impedance of the frozen food, the step of obtaining the current network impedance value of the impedance matching network is performed.

3. The radio frequency defrosting control method as described in claim 1 or 2, characterized in that, Obtaining the current network impedance value of the impedance matching network includes: The switching state of each switching element in the impedance matching network is obtained, wherein the impedance matching network includes multiple variable capacitor combinations, each variable capacitor combination is multiple controllable capacitors connected in parallel, and each controllable capacitor is a capacitor element and a switching element connected in series. The current network impedance value of the impedance matching network is determined based on the switching state of each switching element in the impedance matching network.

4. The radio frequency defrosting control method as described in claim 1 or 2, characterized in that, The step of determining the current parameter value of the target parameter of the frozen food based on the current network impedance value includes: The current load impedance value of the frozen food is determined based on the current network impedance value of the impedance matching network. Obtain the current parameter value of the target parameter from the current load impedance value.

5. The radio frequency defrosting control method as described in claim 4, characterized in that, The step of obtaining the current parameter value of the target parameter from the current load impedance value includes: The real part and / or imaginary part of the current load impedance value are obtained as the current parameter value of the target parameter.

6. The radio frequency defrosting control method as described in claim 4, characterized in that, The step of determining the parameter change characteristics of the target parameter based on the current parameter value includes: Based on the real part value of the current load impedance value and the real part value of the historical load impedance value of the frozen food, determine the current change characteristics of the real part of the load impedance of the frozen food. and / or Based on the imaginary part of the current load impedance value and the imaginary part of the historical load impedance values ​​of the frozen food, the current variation characteristics of the imaginary part of the load impedance of the frozen food are determined.

7. The radio frequency defrosting control method as described in claim 1, characterized in that, The parameter change characteristics include the current change characteristics of the real part of the load impedance. The step of determining whether to end the radio frequency defrosting of the frozen food based on whether the parameter change characteristics conform to the change characteristics of the target temperature range includes: Determine whether the current change characteristics of the real part of the load impedance meet the first target characteristics. The first target characteristics are the change characteristics of the real part of the load impedance in the target temperature range, which is the temperature range required to be reached at the end of thawing. If the current change characteristic of the real part of the load impedance matches the first target characteristic, the radio frequency defrosting of the frozen food is terminated.

8. The radio frequency defrosting control method as described in claim 7, characterized in that, The current change characteristics of the real part of the load impedance include the current rate of change and / or the current acceleration of change of the real part of the load impedance; The step of determining whether the current change characteristic of the real part of the load impedance meets the first target characteristic includes: Determine whether the difference between the current rate of change of the real part of the load impedance and the historical rate of change is greater than a first preset threshold, and / or determine whether the direction of the current acceleration of the real part of the load impedance relative to the historical acceleration has changed; If any judgment result is yes, it is determined that the current change characteristic of the real part of the load impedance conforms to the first target characteristic.

9. The radio frequency defrosting control method as described in claim 1, characterized in that, The parameter change characteristics include the current change characteristics of the imaginary part of the load impedance. The step of determining whether to end the radio frequency defrosting of the frozen food based on whether the parameter change characteristics conform to the change characteristics of the target temperature range includes: Determine whether the current change characteristics of the imaginary part in the load impedance meet the second target characteristics. The second target characteristics are the change characteristics of the imaginary part of the load impedance in the target temperature range, which is the temperature range required to be reached at the end of thawing. If the current change characteristic of the imaginary part of the load impedance matches the second target characteristic, the radio frequency defrosting of the frozen food is terminated.

10. The radio frequency defrosting control method as described in claim 9, characterized in that, The current change characteristics of the imaginary part of the load impedance include the current rate of change and / or the current acceleration of change of the imaginary part of the load impedance; The step of determining whether the current change characteristics of the imaginary part of the load impedance meet the second target characteristics includes: Determine whether the difference between the current rate of change and the historical rate of change of the imaginary part of the load impedance is greater than a second preset threshold; and / or Determine whether the direction of the current change acceleration of the imaginary part of the load impedance has changed relative to the historical change acceleration; If any judgment result is yes, it is determined that the current change characteristic of the imaginary part in the load impedance conforms to the second target characteristic.

11. A radio frequency defrosting control device, characterized in that, Applied to radio frequency (RF) defrosting equipment, the RF defrosting equipment includes an impedance matching network, and the RF defrosting control device includes: Impedance acquisition unit, used to acquire the current network impedance value of the impedance matching network; The parameter determination unit is used to determine the current parameter value of the target parameter of the frozen food according to the current network impedance value, wherein the target parameter is at least one component parameter of the load impedance of the frozen food. The termination judgment unit is used to determine the parameter change characteristics of the target parameter based on the current parameter value, and to determine whether to terminate the radio frequency defrosting of the frozen food based on whether the parameter change characteristics conform to the change characteristics of the target temperature range.

12. A radio frequency defrosting device, characterized in that, include: The memory, the processor, and the computer program stored in the memory and executable on the processor, wherein the processor, when executing the program, implements the steps of the radio frequency defrosting control method as described in any one of claims 1-10.

13. A computer-readable storage medium, characterized in that, It stores a computer program that, when executed by a processor, implements the steps of the radio frequency defrosting control method according to any one of claims 1-10.

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