Patent Application
20230025171
The present invention relates to the field of food processing, and particularly to a control method for an electromagnetic wave heating device, and a heating device.
The quality of foods is kept by freezing. However, frozen foods need to be thawed before processing or consumption. In order to make it convenient for a user to thaw, foods are usually thawed by an electromagnetic wave heating device.
Thawing foods with the electromagnetic wave heating device not only achieves a high speed and high efficiency, but also ensures low losses of nutrients in foods. However, in the prior art, thawing time is input manually by a user, and operating power of an electromagnetic wave generation module is a preset fixed power value. As a result, a requirement on the user is too high, and foods tend to be too cold or too hot after being heated. Moreover, contents of substances in foods of different varieties are different, so the problems of uneven heating and local overheating arise easily.
An objective of a first aspect of the present invention is to provide a control method for an electromagnetic wave heating device. An operating parameter of an electromagnetic wave generation module is determined by a more preferred method.
A further objective of the first aspect of the present invention is to improve the accuracy of an obtained weight of an object to be processed.
Another further objective of the first aspect of the present invention is to avoid the occurrence of overheating.
An objective of a second aspect of the present invention is to provide an electromagnetic wave heating device.
According to the first aspect of the present invention, a control method for a heating device is provided, the heating device including an electromagnetic wave generation module configured to generate an electromagnetic wave signal for heating an object to be processed, the control method including:
determining or obtaining attribute information of the object to be processed, the attribute information at least including food groups, and each of the food groups including at least one food variety;
determining operating power and/or operating time of the electromagnetic wave generation module according to the attribute information; and
controlling the electromagnetic wave generation module to operate according to the operating power and/or the operating time.
Optionally, the attribute information further includes a feature measure reflecting a weight of the object to be processed.
Optionally, the step of determining operating power and/or operating time of the electromagnetic wave generation module according to the attribute information includes:
matching a power base of the operating power according to the feature measure in accordance with a preset power base correspondence, and matching a power coefficient of the operating power according to the food groups in accordance with a preset power coefficient correspondence; and
calculating the operating power according to the power base and the power coefficient, the power base correspondence recording power bases corresponding to different feature measures, and the power coefficient correspondence recording power coefficients corresponding to different food groups.
Optionally, the step of determining operating power and/or operating time of the electromagnetic wave generation module according to the attribute information includes:
matching the operating power according to the food groups and the feature measure in accordance with a preset power correspondence, the power correspondence recording operating power corresponding to different food groups and different feature measures.
Optionally, the step of determining operating power and/or operating time of the electromagnetic wave generation module according to the attribute information includes:
matching a time base of the operating time according to the feature measure in accordance with a preset time base correspondence, and matching a time coefficient of the operating time according to the food groups in accordance with a preset time coefficient correspondence; and
calculating the operating time according to the time base and the time coefficient, the time base correspondence recording time bases corresponding to different feature measures, and the time coefficient correspondence recording time coefficients corresponding to different food groups.
Optionally, the step of determining operating power and/or operating time of the electromagnetic wave generation module according to the attribute information includes:
matching the operating time according to the food groups and the feature measure in accordance with a preset time correspondence, the time correspondence recording operating time corresponding to different food groups and different feature measures.
Optionally, the attribute information further includes an initial temperature of the object to be processed.
Optionally, the step of determining operating power and/or operating time of the electromagnetic wave generation module according to the attribute information includes:
matching a power base of the operating power according to the feature measure and the initial temperature of the object to be processed in accordance with a preset power base correspondence, and matching a power coefficient of the operating power according to the food groups in accordance with a preset power coefficient correspondence; and
calculating the operating power according to the power base and the power coefficient, the power base correspondence recording power bases corresponding to different feature measures and different initial temperatures, and the power coefficient correspondence recording power coefficients corresponding to different food groups.
Optionally, the step of determining operating power and/or operating time of the electromagnetic wave generation module according to the attribute information includes:
matching the operating power according to the food groups, the feature measure, and the initial temperature of the object to be processed in accordance with a preset power correspondence, the power correspondence recording operating power corresponding to different initial temperatures, different food groups, and different feature measures.
Optionally, the step of determining operating power and/or operating time of the electromagnetic wave generation module according to the attribute information includes:
matching a time base of the operating time according to the feature measure and the initial temperature of the object to be processed in accordance with a preset time base correspondence, and matching a time coefficient of the operating time according to the food groups in accordance with a preset time coefficient correspondence; and
calculating the operating time according to the time base and the time coefficient, the time base correspondence recording time bases corresponding to different feature measures and different initial temperatures, and the time coefficient correspondence recording time coefficients corresponding to different food groups.
Optionally, the step of determining operating power and/or operating time of the electromagnetic wave generation module according to the attribute information includes:
matching the operating time according to the food groups, the feature measure, and the initial temperature of the object to be processed in accordance with a preset time correspondence, the time correspondence recording operating time corresponding to different initial temperatures, different food groups, and different feature measures.
Optionally, the control method further includes:
obtaining a feature measure reflecting a weight of the object to be processed;
determining whether the feature measure is less than or equal to a preset lower limit threshold;
controlling the electromagnetic wave generation module to stop operating if YES; and
controlling the electromagnetic wave generation module to operate according to an operating parameter if NO.
Optionally, the control method further includes:
obtaining a feature measure reflecting a weight of the object to be processed;
determining whether the feature measure is more than or equal to a preset upper limit threshold;
controlling the electromagnetic wave generation module to stop operating if YES; and
controlling the electromagnetic wave generation module to operate according to an operating parameter if NO.
Optionally, the feature measure is the weight.
Optionally, the heating device further includes a cavity capacitor configured for placement of the object to be processed, and the feature measure is a capacitance of the cavity capacitor.
Optionally, the heating device further includes a matching module configured to adjust an own impedance to adjust a load impedance of the electromagnetic wave generation module. The step of obtaining a feature measure reflecting a weight of the object to be processed includes:
controlling the electromagnetic wave generation module to generate an electromagnetic wave signal of preset initial power;
adjusting the impedance of the matching module, and determining an impedance value of the matching module implementing optimal load matching of the electromagnetic wave generation module; and
determining the capacitance according to the impedance value.
Optionally, the step of obtaining a feature measure reflecting a weight of the object to be processed includes:
controlling the electromagnetic wave generation module to generate an electromagnetic wave signal of preset initial power;
adjusting a frequency of the electromagnetic wave signal in a candidate frequency interval, and determining a frequency value of the electromagnetic wave signal implementing optimal frequency matching of the cavity capacitor; and
determining the capacitance according to the frequency value.
Optionally, the food groups are divided according to a content range of a set substance, the set substance being water or protein.
The operating power is positively correlated with a content of the set substance in the food groups, and/or the operating time is positively correlated with the content of the set substance in the food groups.
According to the second aspect of the present invention, a heating device is provided, including:
a cavity capacitor, configured for placement of an object to be processed;
an electromagnetic wave generation module, configured to generate an electromagnetic wave signal for heating the object to be processed in the cavity capacitor; and
a controller, configured to perform any above-mentioned control method.
According to the present invention, an operating parameter of the electromagnetic wave generation module is determined according to the food group where the object to be processed is located, thereby reducing uneven heating and local overheating caused by different contents of substances in foods of different varieties as compared with using a fixed operating parameter.
Further, according to the present invention, the operating power of the electromagnetic wave generation module is matched according to a water content range and a weight of the object to be processed, so that the electromagnetic wave generation module can only output several electromagnetic wave signals of fixed power. Therefore, the control is simple, the circuit is simple, and the service life is long.
Particularly, it is creatively found by the inventor of the present application that, although it theoretically seems right to keep the operating power and operating time of the electromagnetic wave generation module in linear relations with water contents of foods, many users do not know clearly about water contents of foods, so it is impossible to achieve good technical effects based on water contents with relatively big errors input by the users or obtained by detection, and particularly for foods containing unevenly distributed substances, the problem that part of the food is still relatively cold while the other part has been cooked (for example, the fat part of streaky pork is cooked first) arises easily. By overcoming a technology bias of the prior art, it is creatively found by the inventor of the present application that power and time may be segmented rather than linearly selected strictly according to water contents. In the present invention, foods of different varieties are divided into food groups appropriately. Therefore, higher tolerance is achieved, weight and temperature detection errors may be tolerated, and uneven heating caused by uneven distributions of substances in the foods is avoided. Moreover, when the food groups are input by a user, the user has no need to know about a water content of each variety, so a requirement on the user is reduced.
Further, according to the present invention, the weight of the object to be processed is reflected by the capacitance of the cavity capacitor, and it is unnecessary to input the weight of the object to be processed manually by a user (based on experience or by measurement), or arrange any weighing sensor additionally in the cavity capacitor. Therefore, the cost is reduced, and the error tolerance rate is increased.
The above, as well as other objectives, advantages and features of the present invention will be better understood by those skilled in the art according to the following detailed descriptions made to specific embodiments of the present invention in conjunction with the accompanying drawings.
In the following part, some specific embodiments of the present invention will be described in detail in an exemplary rather than limited manner with reference to the accompanying drawings. The same reference numerals in the accompanying drawings indicate the same or similar components or parts. Those skilled in the art should understand that these accompanying drawings are not necessarily drawn to scale. In figures:
Specifically, the cavity capacitor 110 may include a cavity configured for placement of an object to be processed 150 and a radiation polar plate arranged in the cavity. In some embodiments, a receiving polar plate may further be arranged in the cavity, so as to form a capacitor with the radiation polar plate. In some other embodiments, the cavity may be made of a metal, so as to form, as a receiving polar plate, a capacitor with the radiation polar plate.
The electromagnetic wave generation module 120 may be configured to generate an electromagnetic wave signal, and is electrically connected with the radiation polar plate of the cavity capacitor 110 so as to generate an electromagnetic wave in the cavity capacitor 110 to heat the object to be processed 150 in the cavity capacitor 110.
Particularly, the processing unit 141 may be configured to, after acquiring a heating instruction, determine or obtain attribute information of the object to be processed 150, determine one or more operating parameters of the electromagnetic wave generation module 120 according to the attribute information, and control the electromagnetic wave generation module 120 to operate according to the one or more operating parameters.
The attribute information may at least include food groups, and each of the food groups may include at least one food variety. The quantity of the food groups is two or more than two. The operating parameter may be operating power and operating time.
According to the heating device 100 of the present invention, the operating parameter of the electromagnetic wave generation module 120 is determined according to the food group where the object to be processed 150 is located, thereby reducing uneven heating and local overheating caused by different contents of substances in foods of different varieties as compared with using a fixed operating parameter.
In the present invention, the food groups may be input by a user, or determined by image recognition, spectral recognition, or the like.
The food groups may be divided according to a content of a set substance, the set substance being water or protein. A specific heat capacity of a food is substantially positively correlated with contents of water and proteins, so the food groups may be divided according to specific heat capacities of foods.
In some embodiments, the operating power of the electromagnetic wave generation module 120 may be positively correlated with a content of a set substance in the food groups, and/or the operating time of the electromagnetic wave generation module 120 may be positively correlated with the content of the set substance in the food groups. Therefore, the heating efficiency is ensured, and meanwhile, safety hazards caused by local overheating of a food and overheating of a power amplifier of the electromagnetic wave generation module 120 are avoided.
Particularly, it is creatively found by the inventor of the present application that, although it theoretically seems right to keep the operating power and operating time of the electromagnetic wave generation module 120 in linear relations with contents of substances in foods, many users do not know clearly about contents of substances in foods, so it is impossible to achieve good technical effects based on contents of substances with relatively big errors input by the users or obtained by detection, and particularly for foods containing unevenly distributed substances, the problem that part of the food is still relatively cold while the other part has been cooked (for example, the fat part of streaky pork is cooked first) arises easily. By overcoming a technology bias of the prior art, it is creatively found by the inventor of the present application that power and time may be segmented rather than linearly selected strictly according to a content of a substance. In the present invention, foods of different varieties are divided into food groups appropriately. Therefore, higher tolerance is achieved, weight and temperature detection errors may be tolerated, and uneven heating caused by uneven distributions of substances in the foods is avoided. Moreover, when the food groups are input by a user, the user has no need to know about a content of a substance in each variety, so a requirement on the user is reduced.
Specifically, in a first group of embodiments, the attribute information of the object to be processed may further include a feature measure reflecting a weight of the object to be processed 150, so as to match a more suitable operating parameter. The operating power of the electromagnetic wave generation module 120 may be determined according to the food groups of the object to be processed 150 and the feature measure reflecting the weight of the object to be processed 150. The operating time of the electromagnetic wave generation module 120 may be determined according to the food groups of the object to be processed 150 and the feature measure reflecting the weight of the object to be processed 150.
In some further embodiments, the processing unit 141 may be configured to match a power base of the operating power according to the feature measure reflecting the weight of the object to be processed 150 in accordance with a preset power base correspondence, match a power coefficient of the operating power according to the food groups of the object to be processed 150 in accordance with a preset power coefficient correspondence, and calculate the operating power according to the power base and the power coefficients, so as to facilitate the design and modification of a control program. The power base correspondence records power bases corresponding to different feature measures. The power coefficient correspondence records power coefficients corresponding to different food groups.
The processing unit 141 may be configured to match a time base of the operating time according to the feature measure reflecting the weight of the object to be processed 150 in accordance with a preset time base correspondence, match a time coefficient of the operating time according to the food groups of the object to be processed 150 in accordance with a preset time coefficient correspondence, and calculate the operating time according to the time base and the time coefficient, so as to facilitate the design and modification of the control program. The time base correspondence records time parameters corresponding to different feature measures. The time coefficient correspondence records time coefficients corresponding to different food groups. The power coefficient and the time coefficient may be unequal.
For example, foods are divided into a first food group and a second food group. A water content range of the first food group may be more than or equal to 60%, e.g., lean pork, beef, mutton, chicken, duck, and fish fillets. A water content range of the second food group may be less than 60%, e.g., streaky pork, chicken feet, fish, pig's feet, pork ribs, and shrimps. A power base corresponding to 100 to 250 g is 50 W, a time base corresponding to 100 to 150 g is 7 min, a time base corresponding to 150 to 200 g is 8 min, and a time base corresponding to 200 to 250 g is 9 min. A power base corresponding to 250 to 1,500 g is 100 W, a time base corresponding to 250 to 300 g is 10 min, a time base corresponding to 300 to 350 g is 11 min, and in a similar fashion, a time base corresponding to 1,450 to 1,500 g is 35 min. Both a power coefficient and a time coefficient of the first food group are 1. A power coefficient of the second food group is 0.5, while a time coefficient thereof is 0.6.
In some other further embodiments, the processing unit 141 may be configured to directly match the operating power according to the food groups and the feature measure of the object to be processed 150 in accordance with a preset power correspondence. The power correspondence records operating power corresponding to different food groups and different feature measures.
The processing unit 141 may be configured to directly match the operating time according to the food groups and the feature measure of the object to be processed 150 in accordance with a preset time correspondence. The time correspondence records operating time corresponding to different food groups and different feature measures. In the present invention, the correspondences may be stored in the storage unit 142 in form of a table, a formula, etc.
In a second group of embodiments, a method for determining the operating power and the operating time differs from that in the first group of embodiments in that the attribute information of the object to be processed may further include an initial temperature of the object to be processed 150. The operating power and operating time of the electromagnetic wave generation module 120 may be determined according to the food groups, the feature measure, and the initial temperature of the object to be processed 150, so as to further avoid the object to be processed being too cold or too hot to further improve the heating efficiency.
In some further embodiments, the processing unit 141 may be configured to match a power base of the operating power according to the feature measure and the initial temperature in accordance with a preset power base correspondence, match a power coefficient of the operating power according to the food groups in accordance with a preset power coefficient correspondence, and calculate the operating power according to the power base and the power coefficient. The power base correspondence may record power bases corresponding to different feature measures and different initial temperatures. The power coefficient correspondence may record power coefficients corresponding to different food groups. The operating power may be obtained by multiplying the power base and the power coefficient.
The processing unit 141 may be configured to match a time base of the operating time according to the feature measure and the initial temperature in accordance with a preset time base correspondence, match a time coefficient of the operating time according to the food groups in accordance with a preset time coefficient correspondence, and calculate the operating time according to the time base and the time coefficient. The time base correspondence may record time bases corresponding to different feature measures and different initial temperatures. The time coefficient correspondence may record time coefficients corresponding to different food groups. The operating time may be obtained by multiplying the time base and the time coefficient. The power coefficient and the time coefficient may be unequal.
For example, foods are divided into a first food group and a second food group. A water content range of the first food group may be more than or equal to 60%, e.g., lean pork, beef, mutton, chicken, duck, and fish fillets. A water content range of the second food group may be less than 60%, e.g., streaky pork, chicken feet, fish, pig's feet, pork ribs, and shrimps. A power base corresponding to 100 to 250 g is 50 W, and a power base corresponding to 250 to 1,500 g is 100 W. A time base corresponding to 100 to 250 g and an initial temperature of less than or equal to −15° C. is 7 min, a time base corresponding to 100 to 250 g and an initial temperature of above −15° C. and less than or equal to −10° C. is 5 min, and a time base corresponding to 100 to 250 g and an initial temperature of above −10° C. and less than or equal to −5° C. is 2 min. A time base corresponding to 250 to 500 g and an initial temperature of less than or equal to −15° C. is 13 min, a time base corresponding to 250 to 500 g and an initial temperature of above −15° C. and less than or equal to −10° C. is 9 min, a time base corresponding to 250 to 500 g and an initial temperature of above −10° C. and less than or equal to −5° C. is 3 min, and so on. Both a power coefficient and a time coefficient of the first food group are 1. A power coefficient of the second food group is 0.5, while a time coefficient thereof is 0.6.
In some other further embodiments, the processing unit 141 may be configured to directly match the operating power according to the food groups, the feature measure, and the initial temperature in accordance with a preset power correspondence. The power correspondence may record operating power corresponding to different food groups and different feature measures under different initial temperatures.
The processing unit 141 may be configured to directly match the operating time according to the food groups, the feature measure, and the initial temperature in accordance with a preset time correspondence. The time correspondence may record operating time corresponding to different food groups and different feature measures under different initial temperatures.
In a third group of embodiments, a method for determining the operating power and the operating time differs from that in the first group of embodiments in that the operating time may be determined according to the feature measure of the object to be processed 150.
For example, the processing unit 141 may be configured to match the operating power according to the food groups and the feature measure in accordance with a preset power correspondence, and match the operating time according to the feature measure in accordance with a preset time correspondence. The power correspondence records operating power corresponding to different food groups and different feature measures. The time correspondence records operating time corresponding to different feature measures.
In a fourth group of embodiments, a method for determining the operating power and the operating time differs from that in the first group of embodiments in that the operating time may be determined according to the feature measure and the initial temperature of the object to be processed 150.
For example, the processing unit 141 may be configured to match the operating power according to the food groups and the feature measure in accordance with a preset power correspondence, and match the operating time according to the feature measure and the initial temperature in accordance with a preset time correspondence. The power correspondence records operating power corresponding to different food groups and different feature measures. The time correspondence records operating time corresponding to different feature measures and different initial temperatures.
In a fifth group of embodiments, a method for determining the operating power and the operating time differs from that in the first or second group of embodiments in that the operating power of the electromagnetic wave generation module 120 may be determined according to the feature measure of the object to be processed 150.
For example, the processing unit 141 may be configured to match the operating power according to the feature measure in accordance with a preset power correspondence, and match the operating time according to the food groups and the feature measure in accordance with a preset time correspondence. The power correspondence records operating power corresponding to different feature measures. The time correspondence records operating time corresponding to different food groups and different feature measures.
For example, the processing unit 141 may be configured to match the operating power according to the feature measure in accordance with a preset power correspondence, and match the operating time according to the food groups, the feature measure, and the initial temperature in accordance with a preset time correspondence. The power correspondence records operating power corresponding to different feature measures. The time correspondence records operating time corresponding to different food groups, different feature measures, and different initial temperatures.
In a sixth group of embodiments, the operating power of the electromagnetic wave generation module 120 may be determined according to the food groups of the object to be processed 150 only. The operating time may be determined according to the method for determining the operating time in any one of the above-mentioned embodiments.
For example, the processing unit 141 may be configured to match the operating power according to the food groups of the object to be processed 150 in accordance with a preset power correspondence. The processing unit 141 may further be configured to match the operating time according to the feature measure in accordance with a preset time correspondence. The power correspondence records operating power corresponding to different food groups. The time correspondence records operating time corresponding to different feature measures.
In some embodiments, the processing unit 141 may be configured to, when the feature measure is less than or equal to a preset lower limit threshold, control the electromagnetic wave generation module 120 to stop operating, so as to avoid an excessively small feature measure of the object to be processed 150 causing burnout of the electromagnetic wave generation module 120 when the heating device 100 has no matching function and causing serious heating of a matching module or a variable-frequency source to result in the reduction of the heating efficiency as well as potential safety hazards when the heating device 100 has a matching function; and when the feature measure is more than or equal to a preset upper limit threshold, control the electromagnetic wave generation module 120 to stop operating so as to avoid an excessively large feature measure of the object to be processed 150 causing a poor heating effect. The lower limit threshold and the upper limit threshold may be determined according to a volume of the cavity capacitor 110 and a configuration of the matching module (or the variable-frequency source). In some exemplary embodiments, a weight of the object to be processed corresponding to the lower limit threshold may be 100 g, and a weight of the object to be processed corresponding to the upper limit threshold may be 1,500 g.
In some embodiments, the heating device 100 may further include an interaction module, configured to send a visual signal or an acoustic signal to a user. The processing unit 141 may further be configured to, when the feature measure is less than or equal to the preset lower limit threshold, control the interaction module to send a visual and/or acoustic signal indicating no-loading to the user, and when the feature measure is more than or equal to the preset upper limit threshold, control the interaction module to send a visual and/or acoustic signal indicating overloading to the user. Therefore, user experiences are improved.
In some embodiments, the feature measure reflecting the weight of the object to be processed 150 may be the weight, which may be measured by a weighing sensor.
In some other embodiments, the feature measure reflecting the weight of the object to be processed 150 may be a capacitance of the cavity capacitor 110.
According to the heating device 100 of the present invention, the weight of the object to be processed 150 is reflected by the capacitance of the cavity capacitor 110, and it is unnecessary to input the weight of the object to be processed 150 manually by a user (based on experience or by measurement), or arrange any weighing sensor additionally in the cavity capacitor 110. Therefore, the cost is reduced, and the error tolerance rate is increased. Particularly, the capacitance of the cavity capacitor 110 comprehensively reflects the weight and temperature of the object to be processed 150, and is particularly suitable for the first group of embodiments of the present invention with an excellent heating effect.
In some embodiments, the heating device 100 further includes a matching module 130. The matching module 130 may be connected in series between the electromagnetic wave generation module 120 and the cavity capacitor 110 or in parallel with two ends of the cavity capacitor 110, and is configured to adjust an own impedance to adjust a load impedance of the electromagnetic wave generation module 120, so as to implement load matching and improve the heating efficiency.
The processing unit 141 may be configured to control the electromagnetic wave generation module 120 to generate an electromagnetic wave signal of preset initial power, adjust the impedance of the matching module 130 for load matching, determine an impedance value of the matching module 130 implementing optimal load matching of the electromagnetic wave generation module 120, and further determine the capacitance of the cavity capacitor according to the impedance value of the matching module 130 implementing optimal load matching.
The matching module 130 may include multiple matching branches that may be switched on and off independently. The processing unit 141 may further be configured to traverse on-off combinations of the multiple matching branches, obtain a matching degree parameter corresponding to each on-off combination and reflecting a load matching degree of the electromagnetic wave generation module 120, compare the matching degree parameters corresponding to the on-off combinations of the multiple matching branches, and determine the on-off combination implementing optimal load matching and an impedance value corresponding to the on-off combination according to a comparison result.
Specifically, the storage unit 142 may store a pre-configured number set. The number set may include combination numbers of the on-off combinations of the multiple matching branches, and the combination numbers correspond to impedance values of the matching module 130. Furthermore, the processing unit 141 may be configured to, after acquiring a heating instruction, obtain the pre-configured number set, determine branch numbers of the matching branches corresponding to each combination number according to the number set, and control the corresponding matching branches to be switched on and off according to the branch numbers to implement the traversing of the on-off combinations of the multiple matching branches.
According to the heating device 100 of the present invention, each on-off combination and each matching branch of the matching module 130 are numbered, so that the matching branches corresponding to each on-off combination can be matched rapidly to be switched on and off during the determination of the impedance value of the matching module 130 implementing optimal load matching of the electromagnetic wave generation module 120. Further, time required for determining the capacitance of the cavity capacitor 110 is shortened, and user experiences are improved greatly.
The branch numbers of the multiple matching branches may sequentially be the 0th to (n−1)-th power of a constant A. The combination number may be a sum of the branch numbers of the matching branches that are switched on in the on-off combination. Therefore, the only one group of matching branches that are switched on may be determined accurately according to the branch numbers only. The constant A may be 2, 3, 4, or the like, and n is the quantity of the matching branches. In the present invention, the constant A may be 2, so that a storage space occupied by the numbers can be reduced, and the matching efficiency is improved.
Capacitance values of constant capacitors of the multiple second matching units 132 of the first matching unit 131 and the second matching unit 132 may be unequal. A capacitance value of a minimum constant capacitor of the second matching unit 132 may be greater than that of a maximum constant capacitor of the first matching unit 131. Multiple branch numbers may sequentially increase according to the capacitance values of the corresponding matching branches.
Referring to
According to the numbering method of the present invention, the combination number may be directly compared with a preset impedance threshold to determine the impedance of the matching module 130. Therefore, a control flow is simplified, and matching time of the heating device 100 is further shortened.
According to a resonant frequency calculation formula f=1/(2π·sqrt(L·C)), for the same heating device 100 (an inductance L remains unchanged), when a capacitance value C of the cavity capacitor 110 changes due to the placement of different objects to be processed 150 therein, a resonant frequency f suitable for the cavity capacitor 110 also changes. In some other embodiments, the electromagnetic wave generation module 120 may include a variable-frequency source and a power amplifier.
The processing unit 141 may be configured to, after acquiring a heating instruction, control the electromagnetic wave generation module 120 to generate an electromagnetic wave signal of preset initial power, adjust a frequency of the electromagnetic wave signal generated by the electromagnetic wave generation module 120 in a candidate frequency interval, determine a frequency value of the electromagnetic wave signal implementing optimal frequency matching of the cavity capacitor 110, and further determine the capacitance of the cavity capacitor 110 according to the frequency value implementing optimal frequency matching.
A minimum value of the candidate frequency interval may be 32 to 38 MHz, while a maximum value thereof may be 42 to 48 MHz. Therefore, the transmittance of an electromagnetic wave is improved, and even heating is implemented. For example, the candidate frequency interval is 32 to 48 MHz, 35 to 48 MHz, 35 to 45 MHz, 38 to 45 MHz, or 38 to 42 MHz.
The processing unit 141 may be configured to adjust the frequency of the electromagnetic wave signal in the candidate frequency interval by a bisection method to gradually narrow a frequency approximation interval implementing optimal frequency matching to a minimum approximation interval, and further determine the frequency value of the electromagnetic wave signal implementing optimal frequency matching.
Specifically, the processing unit 141 may be configured to adjust the frequency of the electromagnetic wave signal to a minimum value, an intermediate value and a maximum value of the frequency approximation interval to obtain a matching degree parameter corresponding to each frequency and reflecting a frequency matching degree of the cavity capacitor 110 for comparison, redetermine a frequency approximation interval according to a comparison result, repeat the operations until the frequency approximation interval is the minimum approximation interval, adjust the frequency of the electromagnetic wave signal to a minimum value, an intermediate value and a maximum value of the minimum approximation interval to obtain a matching degree parameter corresponding to each frequency and reflecting a frequency matching degree of the cavity capacitor 110 for comparison, and determine an optimal frequency value according to a comparison result. The initial frequency approximation interval may be the above-mentioned candidate frequency interval.
According to the heating device 100 of the present invention, the frequency value implementing optimal frequency matching is determined in the candidate frequency interval by the bisection method. Therefore, a range of the interval where the optimal frequency value is located may be narrowed rapidly, the optimal frequency value may further be determined rapidly, time required for determining the capacitance of the cavity capacitor 110 is shortened, and user experiences are improved greatly.
It is to be noted that, in the present invention, the minimum approximation interval is a minimum range of the frequency approximation interval, i.e., the accuracy of the optimal frequency value, rather than an interval of a specific frequency range. In some embodiments, the minimum approximation interval may be any numerical value from 0.2 to 20 KHz, such as 0.2 KHz, 1 KHz, 5 KHz, 10 KHz, or 20 KHz. A time interval between two adjustments of the frequency of the electromagnetic wave signal may be 10 to 20 ms, such as 10 ms, 15 ms, or 20 ms.
In some embodiments, the variable-frequency source may be a voltage-controlled oscillator, of which an input voltage corresponds to an output frequency. The processing unit 141 may be configured to determine the capacitance of the cavity capacitor 110 according to the input voltage of the voltage-controlled oscillator.
In the present invention, optimal load matching of the electromagnetic wave generation module 120 and optimal frequency matching of the cavity capacitor 110 refer to that a proportion of output power allocated to the cavity capacitor 110 by the electromagnetic wave generation module 120 in the same heating device is maximum.
In the present invention, the preset initial power may be 10 to 20 W, such as 10 W, 15 W, or 20 W. Therefore, energy is saved, and meanwhile, the accuracy of the obtained impedance value implementing optimal load matching or the obtained frequency value implementing optimal frequency matching is high.
In some embodiments, the heating device 100 may further include a bidirectional coupler connected in series between the cavity capacitor 110 and the electromagnetic wave generation module 120 and configured to monitor a forward power signal output by the electromagnetic wave generation module 120 and a backward power signal returned to the electromagnetic wave generation module 120 in real time.
The processing unit 141 may further be configured to, after the impedance value of the matching module 130 or the frequency of the electromagnetic wave signal is adjusted each time, obtain the forward power signal output by the electromagnetic wave generation module 120 and the backward power signal returned to the electromagnetic wave generation module 120, and calculate the matching degree parameter according to the forward power signal and the backward power signal.
The matching degree parameter may be a return loss S11, which may be calculated according to the following formula: S11=−20 log(backward power/forward power). In this embodiment, the smaller the numerical value of the return loss S11 is, the higher a load matching degree of the electromagnetic wave generation module 120 or a frequency matching degree of the cavity capacitor 110 is. An impedance value or frequency value corresponding to a minimum return loss S11 is the impedance value implementing optimal load matching or the frequency value implementing optimal frequency matching.
The matching degree parameter may alternatively be an electromagnetic wave absorption rate, which can be calculated according to the following formula: electromagnetic wave absorption rate=(1−backward power/forward power). In this embodiment, the larger the numerical value of the electromagnetic wave absorption rate is, the higher the load matching degree of the electromagnetic wave generation module 120 or the frequency matching degree of the cavity capacitor 110 is. An impedance value or frequency value corresponding to a maximum electromagnetic wave absorption rate is the impedance value implementing optimal load matching or the frequency value implementing optimal frequency matching.
The matching degree parameter may alternatively be other parameters capable of reflecting a proportion of output power allocated to the cavity capacitor 110 by the electromagnetic wave generation module 120.
In step S402, attribute information of an object to be processed 150 is determined or obtained. In this step, the attribute information may at least include food groups. The food groups may be input by a user, or determined by image recognition, spectral recognition, or the like. Each of the food groups may include at least one food variety. The quantity of the food groups is two or more than two.
In step S404, operating power and/or operating time of an electromagnetic wave generation module 120 are/is determined according to the food groups.
In step S406, the electromagnetic wave generation module 120 is controlled to operate according to the operating power and/or the operating time.
According to the control method of the present invention, an operating parameter of the electromagnetic wave generation module 120 is determined according to the food group where the object to be processed 150 is located, thereby reducing uneven heating and local overheating caused by different contents of substances in foods of different varieties as compared with using a fixed operating parameter.
Specifically, in a first group of embodiments, the attribute information may further include a feature measure reflecting a weight of the object to be processed 150, so as to match a more suitable operating parameter. Before the step S404, the method may further include a step that the feature measure reflecting the weight of the object to be processed 150 is obtained.
In some further embodiments, when the operating power of the electromagnetic wave generation module 120 is determined according to the attribute information, the step S404 may include the following steps.
A power base of the operating power is matched according to the feature measure in accordance with a preset power base correspondence, and a power coefficient of the operating power is matched according to the food groups in accordance with a preset power coefficient correspondence.
The operating power is calculated according to the power base and the power coefficient, so as to facilitate the design and modification of a control program. The power base correspondence may record power bases corresponding to different feature measures, and the power coefficient correspondence may record power coefficients corresponding to different food groups.
When the operating time of the electromagnetic wave generation module 120 is determined according to the attribute information, the step S404 may include the following steps.
A time base of the operating time is matched according to the feature measure in accordance with a preset time base correspondence, and a time coefficient of the operating time is matched according to the food groups in accordance with a preset time coefficient correspondence.
The operating time is calculated according to the time base and the time coefficient, so as to facilitate the design and modification of the control program. The time base correspondence may record time bases corresponding to different feature measures, and the time coefficient correspondence may record time coefficients corresponding to different food groups. The power coefficient and the time coefficient may be unequal.
In some further embodiments, when the operating power of the electromagnetic wave generation module 120 is determined according to the attribute information, the step S404 may include the following step.
The operating power is matched according to the food groups and the feature measure in accordance with a preset power correspondence, the power correspondence recording operating power corresponding to different food groups and different feature measures.
When the operating time of the electromagnetic wave generation module 120 is determined according to the attribute information, the step S404 may include the following step.
The operating time is matched according to the food groups and the feature measure in accordance with a preset time correspondence, the time correspondence recording operating time corresponding to different food groups and different feature measures.
In a second group of embodiments, a method for determining the operating power and the operating time differs from that in the first group of embodiments in that the attribute information may further include an initial temperature of the object to be processed 150. Before the step S404, the method may further include a step that the initial temperature of the object to be processed 150 is obtained.
In some further embodiments, when the operating power of the electromagnetic wave generation module 120 is determined according to the attribute information, the step S404 may include the following steps.
A power base of the operating power is matched according to the feature measure and the initial temperature in accordance with a preset power base correspondence, and a power coefficient of the operating power is matched according to the food groups in accordance with a preset power coefficient correspondence.
The operating power is calculated according to the power base and the power coefficient, so as to further avoid the object to be processed being too cold or too hot to further improve the heating efficiency. The power base correspondence records power bases corresponding to different feature measures and different initial temperatures, and the power coefficient correspondence records power coefficients corresponding to different food groups.
When the operating time of the electromagnetic wave generation module 120 is determined according to the attribute information, the step S404 may include the following steps.
A time base of the operating time is matched according to the feature measure and the initial temperature in accordance with a preset time base correspondence, and a time coefficient of the operating time is matched according to the food groups in accordance with a preset time coefficient correspondence.
The operating time is calculated according to the time base and the time coefficient, so as to further avoid the object to be processed being too cold or too hot to further improve the heating efficiency. The time base correspondence records time bases corresponding to different feature measures and different initial temperatures, and the time coefficient correspondence records time coefficients corresponding to different food groups.
In some other further embodiments, when the operating power of the electromagnetic wave generation module 120 is determined according to the attribute information, the step S404 may include the following step.
The operating power is matched according to the food groups, the feature measure and the initial temperature in accordance with a preset power correspondence, the power correspondence recording operating power corresponding to different initial temperatures, different food groups, and different feature measures.
When the operating time of the electromagnetic wave generation module 120 is determined according to the attribute information, the step S404 may include the following step.
The operating time is matched according to the food groups, the feature measure and the initial temperature in accordance with a preset time correspondence, the time correspondence recording operating time corresponding to different initial temperatures, different food groups, and different feature measures.
In a third group of embodiments, a method for determining the operating power and the operating time differs from that in the first group of embodiments in that, when the operating time of the electromagnetic wave generation module 120 is determined according to the attribute information, the step S404 may include the following step.
The operating time is matched according to the feature measure in accordance with a preset time correspondence, the time correspondence recording operating time corresponding to different feature measures.
In a fourth group of embodiments, a method for determining the operating power and the operating time differs from that in the first group of embodiments in that, before the step S404, the method may further include a step that an initial temperature of the object to be processed is obtained, and when the operating time of the electromagnetic wave generation module 120 is determined according to the attribute information, the step S404 may include the following step.
The operating time is matched according to the feature measure and the initial temperature in accordance with a preset time correspondence, the time correspondence recording operating time corresponding to different feature measures and different initial temperatures.
In a fifth group of embodiments, a method for determining the operating power and the operating time differs from that in the first or second group of embodiments in that, when the operating power of the electromagnetic wave generation module 120 is determined according to the attribute information, the step S404 may include the following step.
The operating power is matched according to the feature measure in accordance with a preset power correspondence, the power correspondence recording operating power corresponding to different feature measures.
In a sixth group of embodiments, a method for determining the operating power and the operating time differs from that in any one of the above groups of embodiments in that, when the operating power of the electromagnetic wave generation module 120 is determined according to the attribute information, the step S404 may include the following step.
The operating power is matched according to the food groups of the object to be processed 150 in accordance with a preset power correspondence, the power correspondence recording operating power corresponding to different food groups.
In step S502, whether the feature measure is less than or equal to a preset lower limit threshold is determined. Step S504 is performed if YES. Step S506 is performed if NO.
In the step S504, the electromagnetic wave generation module 120 is controlled to stop operating, and a visual and/or acoustic signal indicating non-loading is sent to a user, so as to avoid an excessively small feature measure of the object to be processed 150 causing a burnout of the electromagnetic wave generation module 120 when the heating device 100 has no matching function and causing serious heating of a matching module or a variable-frequency source to result in the reduction of the heating efficiency as well as potential safety hazards when the heating device 100 has a matching function.
In the step S506, whether the feature measure is more than or equal to a preset upper limit threshold is determined. Step S508 is performed if YES. Step S510 is performed if NO.
In the step S508, the electromagnetic wave generation module 120 is controlled to stop operating, and a visual and/or acoustic signal indicating overloading is sent to the user, so as to avoid an excessively large feature measure of the object to be processed 150 causing a poor heating effect.
In the step S510, the electromagnetic wave generation module 120 is controlled to operate according to an operating parameter.
In the embodiment shown in
In some embodiments, the feature measure reflecting the weight of the object to be processed 150 may be the weight, which may be measured by a weighing sensor.
In some other embodiments, the feature measure reflecting the weight of the object to be processed 150 may be a capacitance of the cavity capacitor 110.
According to the control method of the present invention, the weight of the object to be processed 150 is reflected by the capacitance of the cavity capacitor 110, and it is unnecessary to input the weight of the object to be processed 150 manually by the user (based on experience or by measurement), or arrange any weighing sensor additionally in the cavity capacitor 110. Therefore, the cost is reduced, and the error tolerance rate is increased.
In step S602, the electromagnetic wave generation module 120 is controlled to generate an electromagnetic wave signal of preset initial power. In this step, the preset initial power may be 10 to 20 W, such as 10 W, 15 W, or 20 W. Therefore, energy is saved, and meanwhile, the accuracy of an obtained impedance value of a matching module 130 implementing optimal load matching is high.
In step S604, an impedance of the matching module 130 is adjusted, and an impedance value of the matching module 130 implementing optimal load matching of the electromagnetic wave generation module 120 is determined.
In step S606, the capacitance of the cavity capacitor 110 is determined according to the impedance value.
In some further embodiments, based on the matching module 130 including multiple matching branches that may be switched on and off independently, the step S604 may include the following steps.
A pre-configured number set is obtained.
Branch numbers of the matching branches corresponding to each combination number are determined one by one according to the number set, the corresponding matching branches are controlled to be switched on and off according to the branch numbers, after the matching branches corresponding to each on-off combination are switched on and off, a forward power signal output by the electromagnetic wave generation module 120 and a backward power signal returned to the electromagnetic wave generation module 120 are obtained, and a matching degree parameter is calculated according to the forward power signal and the backward power signal.
The matching degree parameters corresponding to the on-off combinations of the multiple matching branches are compared.
The on-off combination implementing optimal load matching and an impedance value corresponding to the on-off combination are determined according to a comparison result.
In this embodiment, the number set may include combination numbers of the on-off combinations of the multiple matching branches, and the combination numbers correspond to impedance values of the matching module 130.
The branch numbers of the multiple matching branches may sequentially be the 0th to (n−1)-th power of a constant A. The combination number may be a sum of the branch numbers of the matching branches that are switched on in the on-off combination. The constant A may be 2, 3, 4, or the like, and n is the quantity of the matching branches.
The forward power signal and the backward power signal may be detected by a bidirectional coupler. The matching degree parameter may be a return loss or an electromagnetic wave absorption rate. Specifically, the smaller a numerical value of the return loss, the higher a load matching degree of the electromagnetic wave generation module 120 is. An impedance value of the matching module 130 corresponding to a minimum return loss is the impedance value implementing optimal load matching. The larger a numerical value of the electromagnetic wave absorption rate is, the higher the load matching degree of the electromagnetic wave generation module 120 is. An impedance value of the matching module 130 corresponding to a maximum electromagnetic wave absorption rate is the impedance value implementing optimal load matching.
According to the control method of the present invention, each on-off combination and each matching branch of the matching module 130 are numbered, so that the matching branches corresponding to each on-off combination may be matched rapidly to be switched on and off during the determination of the impedance value of the matching module 130 implementing optimal load matching of the electromagnetic wave generation module 120. Further, time required for determining the capacitance of the cavity capacitor 110 is shortened, and user experiences are improved greatly.
In step S702, the electromagnetic wave generation module 120 is controlled to generate an electromagnetic wave signal of preset initial power. The preset initial power may be 10 to 20 W, such as 10 W, 15 W, or 20 W. Therefore, energy is saved, and meanwhile, the accuracy of an obtained frequency value implementing optimal frequency matching is high.
In step S704, a frequency of the electromagnetic wave signal is adjusted in a candidate frequency interval, and a frequency value of the electromagnetic wave signal implementing optimal frequency matching of the cavity capacitor 110 is determined. A minimum value of the candidate frequency interval may be 32 to 38 MHz, while a maximum value thereof may be 42 to 48 MHz. Therefore, the transmittance of an electromagnetic wave is improved, and even heating is implemented. For example, the candidate frequency interval is 32 to 48 MHz, 35 to 48 MHz, 35 to 45 MHz, 38 to 45 MHz, or 38 to 42 MHz.
In step S706, the capacitance of the cavity capacitor 110 is determined according to the frequency value.
In some further embodiments, the step S704 may be implemented by adjusting the frequency of the electromagnetic wave signal in the candidate frequency interval by a bisection method to gradually narrow a frequency approximation interval implementing optimal frequency matching to a minimum approximation interval, and determining the frequency value of the electromagnetic wave signal implementing optimal frequency matching. It specifically includes the following steps.
An initial frequency approximation interval is obtained, the initial frequency approximation interval being the above-mentioned candidate frequency interval.
The frequency of the electromagnetic wave signal is adjusted to a minimum value, an intermediate value and a maximum value of the frequency approximation interval, after the frequency of the electromagnetic wave signal is adjusted each time, a forward power signal output by the electromagnetic wave generation module 120 and a backward power signal returned to the electromagnetic wave generation module 120 are obtained, and a matching degree parameter corresponding to the frequency is calculated according to the forward power signal and the backward power signal. The forward power signal and the backward power signal may be detected by a bidirectional coupler connected in series between the cavity capacitor 110 and the electromagnetic wave generation module 120.
Matching degree parameters corresponding to each frequency are compared until the frequency approximation interval is a minimum approximation interval. The minimum approximation interval is a minimum range of the frequency approximation interval, i.e., the accuracy of the optimal frequency value, rather than an interval of a specific frequency range. In some embodiments, the minimum approximation interval may be any numerical value from 0.2 to 20 KHz, such as 0.2 KHz, 1 KHz, 5 KHz, 10 KHz, or 20 KHz.
The frequency value of the electromagnetic wave signal implementing optimal frequency matching is determined according to a comparison result.
According to the control method of the present invention, the frequency value implementing optimal frequency matching is determined in the candidate frequency interval by the bisection method. Therefore, a range of the interval where the optimal frequency value is located may be narrowed rapidly, the optimal frequency value may further be determined rapidly, time required for determining the capacitance of the cavity capacitor 110 is shortened, and user experiences are improved greatly.
In step S802, a heating instruction is acquired.
In step S804, food groups and an initial temperature of an object to be processed 150 are obtained.
In step S806, the electromagnetic wave generation module 120 is controlled to generate an electromagnetic wave signal of preset initial power.
In step S808, a pre-configured number set is obtained.
In step S810, branch numbers of matching branches corresponding to each combination number are determined one by one according to the number set, the corresponding matching branches are controlled to be switched on and off according to the branch numbers, after the matching branches corresponding to each on-off combination are switched on and off, a forward power signal output by the electromagnetic wave generation module and a backward power signal returned to the electromagnetic wave generation module 120 are obtained, and a matching degree parameter is calculated according to the forward power signal and the backward power signal.
In step S812, matching degree parameters corresponding to on-off combinations of multiple matching branches are compared.
In step S814, the on-off combination implementing optimal load matching and an impedance value corresponding to the on-off combination are determined according to a comparison result.
In step S816, a capacitance of the cavity capacitor 110 is determined according to the impedance value.
In step S818, whether the capacitance of the cavity capacitor 110 is less than or equal to a preset lower limit threshold is determined. Step S820 is performed if YES. Step S822 is performed if NO.
In the step S820, the electromagnetic wave generation module 120 is controlled to stop operating, and a visual and/or acoustic signal indicating non-loading is sent to a user. The process returns to step S802.
In the step S822, whether the capacitance of the cavity capacitor 110 is more than or equal to a preset upper limit threshold is determined. Step S824 is performed if YES. Step S826 is performed if NO.
In the step S824, the electromagnetic wave generation module 120 is controlled to stop operating, and a visual and/or acoustic signal indicating overloading is sent to the user. The process returns to step S802.
In the step S826, a power base and a time base are matched according to the capacitance of the cavity capacitor 110 and preset base correspondences.
In step S828, power bases and time bases are matched according to the food groups and preset coefficient correspondences.
In step S830, operating power and operating time are calculated according to the power base and power coefficient, and the time base and time coefficient respectively.
In step S832, the electromagnetic wave generation module 120 is controlled to operate according to the operating power.
In step S834, whether the electromagnetic wave generation module 120 has been run for the operating time or more is determined. Step S836 is performed if YES. Step S832 is performed if NO.
In step S836, the electromagnetic wave generation module 120 is controlled to stop operating. The process returns to step S802 to start a next cycle.
The heating device 100 and control method of the present invention are particularly applicable to food thawing, particularly food thawing to −4 to 0° C., i.e., the above-mentioned set temperature −4 to 0° C., and a more accurate feature measure value may be obtained.
Hereto, those skilled in the art should realize that although multiple exemplary embodiments of the present invention have been shown and described in detail herein, without departing from the spirit and scope of the present invention, many other variations or modifications that conform to the principles of the present invention can still be directly determined or deduced from contents disclosed in the present invention. Therefore, the scope of the present invention should be understood and recognized as covering all these other variations or modifications.
| Number | Date | Country | Kind |
|---|---|---|---|
| 201911289225.2 | Dec 2019 | CN | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/CN2020/125513 | 10/30/2020 | WO |
