Microwave control device, microwave heating device, microwave control method, and microwave control program

Abstract

This microwave control device comprises: a calculation unit (115) that calculates a theoretical temperature value of an object to be heated from an amount of heat absorbed by the object to be heated, which is heated by microwave irradiation, and information on the object to be heated including a specific heat and a mass of the object to be heated; and an inference unit (116) that, by using a learning model for inferring a temperature distribution of the object to be heated from the information on the object to be heated and the theoretical temperature value, infers the temperature distribution of the object to be heated from the information on the object to be heated used in the calculation by the calculation unit and the theoretical temperature value calculated by the calculation unit.

Description

Microwave control device, microwave heating device, microwave control method, and microwave control program

[0001] This disclosure relates to microwave control technology.

[0002] Patent Document 1 discloses a microwave processing device comprising: a heating chamber for housing an object to be heated; an oscillation unit; a power distribution unit for distributing the output of the oscillation unit to multiple units; a plurality of power amplification units for each of the outputs of the power distribution unit; a plurality of power supply units for supplying the outputs of the power amplification units to the heating chamber; a power detection unit for detecting the power reflected from the power supply units to the power amplification units; and a control unit for controlling the oscillation frequency of the oscillation unit and the power amplification units, wherein the power supply units are arranged on the walls constituting the heating chamber, and the heating operation is temporarily interrupted when the reflected power detected by the power detection unit exceeds a predetermined value, the output power of the power amplification units is reduced to sweep the oscillation frequency of the oscillation unit over a predetermined interval, and the heating operation is resumed after the frequency is set to the minimum reflected power detected by the power detection unit.

[0003] Japanese Patent Publication No. 2009-252564

[0004] According to the microwave processing apparatus of Patent Document 1, when the reflected power exceeds a predetermined value, the heating operation is temporarily interrupted, the oscillation frequency of the oscillation unit is swept over a predetermined interval, and the heating operation is resumed after it is set to the frequency at which the reflected power detected by the power detection unit is minimized. Since the heating operation is temporarily interrupted when the reflected power exceeds a predetermined value, damage to the microwave generator due to reflected power can be prevented. In addition, since the heating operation is resumed after it is set to the frequency at which the reflected power is minimized, the power conversion efficiency can be improved. However, when heating is performed using the microwave processing apparatus of Patent Document 1, there is a problem that some parts of the object to be heated may be overheated or, conversely, underheated.

[0005] This disclosure was made to solve such problems and aims to provide a microwave control technology that can perform heating while taking into account the temperature distribution of an object heated by microwave irradiation.

[0006] One aspect of a microwave control device according to an embodiment of the present disclosure includes: a calculation unit that calculates a theoretical temperature value of an object to be heated from the amount of heat absorbed by the object to be heated by microwave irradiation and information about the object to be heated, including the specific heat and mass of the object to be heated; and an inference unit that uses a learning model for inferring the temperature distribution of the object to be heated from the information about the object to be heated and the theoretical temperature value to be heated, and infers the temperature distribution of the object to be heated from the information about the object to be heated used in the calculation by the calculation unit and the theoretical temperature value calculated by the calculation unit.

[0007] According to the microwave control technology of the embodiments of this disclosure, heating can be performed while taking into account the temperature distribution of the object to be heated by microwave irradiation.

[0008] This figure shows an example configuration of a microwave control device and a microwave heating device including the microwave control device. This figure shows an example configuration of the hardware of the microwave control device. This figure shows an example configuration of the hardware of the microwave control device. This figure shows an example configuration of a microwave control device and a microwave heating device including the microwave control device. This is a flowchart of the microwave control method.

[0009] Various embodiments of this disclosure will be described in detail below with reference to the drawings. In the drawings, identical or similar parts are denoted by the same or similar reference numerals, and redundant descriptions of such parts will be omitted. In this disclosure, the term "or" is used in the sense of an inclusive OR unless otherwise stated.

[0010] Embodiment 1. <Configuration> Referring to Figure 1, a microwave control device and a microwave heating device according to Embodiment 1 of the present disclosure will be described. As shown in Figure 1, the microwave heating device 1 includes, as an example, a microwave control device 11, a signal generator 12, a tuner 13, a heating furnace 14, a temperature sensor 15, and a power sensor 118. The microwave heating device 1 is a device for heating an object to be heated, such as plastic, which is placed in the heating furnace 14. The signal generator 12 and the tuner 13 constitute a microwave irradiation device that oscillates microwaves according to a control amount calculated by the microwave control device 11 and irradiates with the oscillated microwaves.

[0011] (Microwave Control Device) The microwave control device 11 is a device that controls the microwaves irradiated onto the object to be heated. To realize this function, the microwave control device 11 includes, as an example shown in Figure 1, a setting information acquisition unit 111, a control unit 112, a signal information acquisition unit 113, an information storage unit 114, a calculation unit 115, an inference unit 116, a control amount calculation unit 117, and a temperature information acquisition unit 119. The microwave control device 11 may also include a control unit (not shown) for controlling the overall operation of the microwave control device 11.

[0012] (Setting Information Acquisition Unit) The setting information acquisition unit 111 is a functional unit that acquires setting information about the object to be heated. The setting information includes information about the object to be heated, which represents the physical characteristics of the object to be heated, and a target temperature value, which is the target value to be reached by heating the object to be heated.

[0013] Examples of information about the object to be heated include its three-dimensional shape (length, width, and height), relative permittivity, relative permeability, conductivity, specific heat, or mass. This information is known information obtained through measurements or other means. The information about the object to be heated may be entered by the user of the microwave heating device 1 via an input device not shown, such as a keyboard, or it may be obtained from a database not shown that stores measurement results. The database may store multiple data sets.

[0014] The temperature target value is entered by the user via an input device (not shown).

[0015] (Control Unit) The control unit 112 is a functional unit that receives the output of the control quantity calculation unit 117 and controls the signal generation device 12 and the tuner 13. For example, if the control quantity calculation unit 117 outputs information to rotate the phase of the irradiation signal by X degrees, the control unit 112 instructs the signal generation device 12 to generate a signal rotated by X degrees.

[0016] Furthermore, the control unit 112 outputs control information for controlling the signal generation device 12 and the tuner 13 to the signal information acquisition unit 113.

[0017] (Signal Generator) The signal generator 12 generates a microwave signal based on the input from the control unit 112. For example, the signal generator 12 includes a digital signal processor and an amplifier. More specifically, the signal generator 12 generates a digital microwave signal using the digital signal processor, converts the generated digital microwave signal into an analog microwave signal using a DA converter, applies the analog microwave signal to a diode oscillator circuit to cause the microwave signal to oscillate, amplifies the oscillating microwave signal using an amplifier, and outputs the amplified microwave signal.

[0018] (Tuner) The tuner 13 is an impedance matching device for adjusting the impedance inside the heating furnace 14 based on the output of the control unit. For example, an EH tuner can be used as the tuner 13. Impedance matching is performed by changing the position of the E plunger or H plunger provided by the EH tuner. Note that the impedance inside the heating furnace 14 can be adjusted by changing the frequency with the signal generator 12, so the tuner 13 is not an essential component but an optional component.

[0019] (Heating Furnace) The heating furnace 14 is an applicator for heating an object placed inside it by irradiating the object to be heated with microwaves. The heating furnace 14 is equipped with an inner wall surface made of a metal material such as aluminum and an opening / closing door that opens and closes to allow the object to be heated to be put in and taken out of the heating furnace 14, and is configured to contain the irradiated microwaves inside.

[0020] (Power Sensor) The power sensor 118 is a sensor for measuring the power used to heat the object to be heated (input power - reflected power). More specifically, the power sensor 118 measures the input power irradiated onto the object to be heated and the reflected power reflected from the object to be heated. The power sensor 118 may output the measured input power and reflected power as measurement results, or it may output the difference obtained by subtracting the reflected power from the input power as measurement results. The power sensor 118 outputs the measurement results to the microwave control device 11A.

[0021] (Temperature Sensor) The temperature sensor 15 is mounted on the heating furnace 14 and is a sensor for measuring the temperature of the object to be heated. For example, an infrared temperature sensor can be used as the temperature sensor 15 to measure the surface temperature of the object to be heated. There can be one or more measurement locations, and the accuracy of temperature control improves as the number of locations increases. In other words, temperature unevenness can be suppressed. An infrared thermographic camera may also be used as the temperature sensor 15. The temperature sensor 15 outputs the measurement result to the microwave control device 11. In addition to the measured temperature value, the measurement result includes temperature measurement position information, which is information indicating the measurement point or measurement area where the temperature of the object to be heated was measured.

[0022] (Signal Information Acquisition Unit) The signal information acquisition unit 113 is a functional unit that acquires information on the frequency, phase, and amplitude of the microwaves to be irradiated, information on the tuner 13, and information on the power used for heating (input power - reflected power) from the power sensor 118 (hereinafter sometimes referred to as "signal information") from the control unit 112, and stores the acquired information in the information storage unit 114. The information storage unit 114 is implemented by memory. The information on the tuner 13 refers to position information representing the position of the components that the tuner 13 is equipped with.

[0023] (Temperature Information Acquisition Unit) The temperature information acquisition unit 119 is a functional unit that acquires the temperature of the object to be heated inside the heating furnace 14 from the temperature sensor 15 and stores the acquired temperature in the information storage unit 114.

[0024] (Calculation Unit) The calculation unit 115 is a functional unit that calculates the theoretical value of the temperature of the object to be heated after microwave irradiation. More specifically, the calculation unit 115 calculates the theoretical temperature value of the object to be heated from the amount of heat absorbed by the object to be heated due to microwave irradiation and the information on the object to be heated including the specific heat and mass of the object to be heated. The theoretical temperature value of the object to be heated can be calculated using the following formula (1). Temperature difference ΔT = Heat quantity / (Specific heat × Mass) ・・・(1)

[0025] As an example, the measurement result measured by the power sensor 118 may be used as the amount of heat absorbed by the object to be heated.

[0026] As another example, the amount of heat absorbed by the object to be heated may be calculated by the following formula (2). P

[0028] =P ε +P σ +P μ = (1 / 2)ωε0ε"E 2 +(1 / 2)σE 2 +(1 / 2)ωμ0μ"E 2 ・・・(2)

[0027] The substance irradiated with microwaves is heated by dielectric loss P ε , conduction loss +P σ , or magnetic loss P μ . Formula (2) is an expression representing the heating rate P total (w / m 3 ) per unit volume of the substance, considering all of these losses. In formula (2), E represents the electric field strength, H represents the magnetic field strength, ω represents the frequency, ε0 represents the permittivity of vacuum, μ0 represents the permeability of vacuum, ε" represents the complex permittivity, σ represents the conductivity, and μ" represents the complex permeability. By measuring the electric field strength and magnetic field strength in the heating furnace 14 with a measuring instrument not shown and supplying the measurement results to the calculation unit 115, the calculation unit 115 may calculate the amount of heat absorbed by the object to be heated (P total ) using formula (2). Note that the cumulative value from the start of heating is used for P total .

[0028] The calculation unit 115 uses the measurement result of the power sensor 118 or formula (2) to calculate the amount of heat absorbed by the object to be heated (P totalAfter obtaining the temperature, the temperature difference ΔT is calculated according to equation (1). By adding ΔT to the current temperature value detected by the temperature sensor 15, the theoretical temperature value can be calculated.

[0029] As shown above, the theoretical temperature value calculated using equation (1) is the temperature value per unit mass of the object being heated, and therefore does not take into account the temperature distribution of the object being heated. However, due to various factors such as the fact that the object being heated has a certain size, the microwave propagation path is unique to the heating furnace 14 due to the internal shape of the heating furnace 14, and the heating by microwaves proceeds rapidly, the temperature distribution of the object being heated after microwave irradiation is not uniform. In other words, temperature unevenness occurs. Therefore, the inference unit 116 is used to obtain an inferred value that corrects the theoretical temperature value by taking into account the temperature distribution of the object being heated. In addition, temperature unevenness is suppressed by using multiple temperature sensors 15.

[0030] (Inference Unit) The inference unit 116 is a functional unit that uses a learning model to infer the temperature distribution of a heated object from the heated object information and theoretical temperature values, and infers the temperature distribution of the heated object, which is the object being heated, from the heated object information used in the calculation by the calculation unit 115 and the theoretical temperature values ​​calculated by the calculation unit 115. The inference unit 116 is also a functional unit that acquires the inferred temperature values ​​at the temperature measurement points by the temperature sensor 15 from the inferred temperature distribution and outputs the difference between these inferred temperature values ​​and the actual temperature measured by the temperature sensor 15.

[0031] The learning model may be constructed using a known neural network. Experimental results obtained before operation (information on the object to be heated, theoretical temperature values, and actual temperature sensor readings) are used as training data, and machine learning is performed based on the learning rules of the neural network. Of the training data, the correct data (teaching data) is the actual temperature values ​​at multiple temperature measurement points, i.e., the temperature distribution. The object to be heated is heated in advance, and the actual temperature distribution of the object to be heated is measured using one or more thermal cameras or multiple thermal sensors. These actual temperature values ​​(temperature distributions) at multiple temperature measurement points are used to train the neural network along with the information on the object to be heated and the theoretical temperature values. The learning model constructed in this way may be stored in a storage device (not shown) provided in the microwave control device 11A, or it may be stored in a server device (not shown) that is accessible via a communication line such as the Internet.

[0032] The inference unit 116 inputs the information on the object to be heated, acquired by the setting information acquisition unit 111 and used in the calculation by the calculation unit 115, and the theoretical value of the temperature calculated by the calculation unit 115 into the learning model constructed in this manner, and obtains the inferred temperature distribution from the learning model. The information on the object to be heated, used in the calculation by the calculation unit 115, may be acquired from the calculation unit 115 or from the information storage unit 114.

[0033] Meanwhile, the inference unit 116 acquires the actual temperature value obtained by the temperature information acquisition unit 119. This temperature value is associated with temperature measurement location information.

[0034] The inference unit 116 calculates a temperature difference ΔT by comparing the inferred temperature value at the location indicated by the temperature measurement location information in the inferred temperature distribution with the actual temperature value. If multiple temperature sensors 15 are mounted on the heating furnace 14, the inference unit 116 calculates the temperature difference ΔT according to the number of temperature sensors 15. The inference unit 116 supplies the calculated temperature difference ΔT of 1 or more to the control variable calculation unit 117.

[0035] (Control Quantity Calculation Unit) The control quantity calculation unit 117 is a functional unit that calculates a control quantity based on the temperature difference ΔT obtained by the inference unit 116. Such calculation can be performed, for example, by preparing in advance a table that associates the temperature difference with control quantities such as amplitude, phase, and frequency based on previous measurement results, and the control quantity calculation unit 117 referring to the table to obtain the control quantity corresponding to the temperature difference ΔT. The data held in the table becomes more complex according to the number of temperature sensors. For example, when the result shows that the actual temperature of the object to be heated is lower than the corrected inference value of the temperature, information including any one or two or more of the following controls may be output: increasing the amplitude by AdB from the table, rotating the phase by B degrees, changing the frequency by C, or moving the tuner by Dmm. Note that since the frequency at which the temperature tends to rise varies depending on the substance, the relationship between the high and low temperatures and the high and low frequencies cannot be generally determined. Also, since the position of the tuner at which the temperature tends to rise varies depending on the substance, the relationship between the high and low temperatures and the position of the tuner cannot be generally determined.

[0036] Note that in the first loop before the inference unit 116 performs inference, the control quantity calculation unit 117 calculates the control quantity based on the target value of the temperature stored in the information storage unit 114.

[0037] As described above, by constructing a learning model that learns the temperature distribution correlated with the characteristics of the object to be measured using a single or multiple thermal cameras that sense a wide range, or multiple thermosensors that sense a narrow range, it becomes possible to infer the temperature at each point in that temperature distribution. Therefore, during the actual operation of the microwave heating device, it becomes possible to perform microwave control considering the temperature distribution of the object to be measured at the measurement location by simply measuring the temperature at a certain location in the object to be measured. Therefore, there is an effect that it is not necessary to mount many temperature sensors on the microwave heating device to be manufactured and sold. Also, when measuring the temperatures at multiple measurement locations of the object to be heated by multiple temperature sensors 15, there is an effect that the control accuracy is improved and temperature unevenness can be suppressed.

[0038] Next, an example of the hardware configuration of the microwave control device 11 will be described with reference to Figures 2A and 2B. Each function of the microwave control device 11 is realized by a processing circuit. The processing circuit may be a dedicated processing circuit 100a as shown in Figure 2A, or a processor 100b that executes a program stored in memory 100c as shown in Figure 2B.

[0039] If the processing circuitry is a dedicated processing circuit 100a, the dedicated processing circuit 100a may be, for example, a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC (application-specific integrated circuit), an FPGA (field-programmable gate array), or a combination thereof. The functions of the microwave control device 11 may be realized by multiple separate processing circuits, or the functions of the microwave control device 11 may be realized by a single processing circuit.

[0040] When the processing circuitry is the processor 100b, the functions of the microwave control device 11 are realized by software, firmware, or a combination of software and firmware. The software and firmware are described as programs and stored in the memory 100c. The processor 100b realizes the functions of the microwave control device 11 by reading and executing the programs stored in the memory 100c. Here, examples of the memory 100c include non-volatile or volatile semiconductor memories such as RAM (random access memory), ROM (read-only memory), flash memory, EPROM (erasable programmable read only memory), EEPROM (electrically erasable programmable read-only memory), etc., as well as magnetic disks, flexible disks, optical disks, compact disks, mini disks, and DVDs.

[0041] Note that part of the functions of the microwave control device 11 may be realized by dedicated hardware, and the other functions may be realized by software or firmware. Thus, the processing circuitry can realize the functions of the microwave control device 11 by hardware, software, firmware, or a combination thereof.

[0042] In the above description, the explanation was given in accordance with the configuration in which the microwave control device 11 includes the control unit 112, but the control unit 112 is not an essential functional unit. When omitting the control unit 112, the microwave heating device 1A may be configured as shown in FIG. 3.

[0043] As shown in Figure 3, the microwave heating device 1A comprises a microwave control device 11A, a signal source 16, a phase shifter 17, an amplifier 18, a heating furnace 14, a temperature sensor 15, and a power sensor 118. The microwave heating device 1A may also include a tuner 13 between the amplifier 18 and the heating furnace 14, as in the case of Figure 1. The signal source 16, the phase shifter 17, and the amplifier 18 constitute a microwave irradiation device that irradiates microwaves oscillated according to a calculated control quantity. The microwave irradiation device may also include a tuner 13.

[0044] Unlike the microwave control device 11 shown in Figure 1, the microwave control device 11A does not include a control unit 112. In this configuration, the signal information acquisition unit 113A of the microwave control device 11A acquires information related to the irradiated microwaves from the signal source 16, the phase shifter 17, and the amplifier 18. It acquires frequency from the signal source 16, phase from the phase shifter 17, and amplitude from the amplifier 18.

[0045] The signal source 16 is an oscillator that generates microwaves, such as a magnetron or a voltage-controlled oscillator. The phase shifter 17 shifts the phase of the microwaves output from the signal source 16. The amplifier 18 is used as needed to amplify the microwaves output from the phase shifter 17. The microwaves amplified by the amplifier 18 are supplied to the heating furnace 14.

[0046] <Operation> Next, the operation of the microwave control device 11 (11A) will be explained.

[0047] (Step ST1) In step ST1, the setting information acquisition unit 111 acquires the target temperature value of the object to be heated. The user of the microwave heating device 1 inputs the target temperature value via the input device, and the setting information acquisition unit 111 acquires the input target temperature value.

[0048] Furthermore, in step ST1, the setting information acquisition unit 111 acquires information about the object to be heated, which represents the physical properties of the object to be heated. The information about the object to be heated may be input by the user via an input device, or it may be acquired from a database that stores measurement results.

[0049] (Step ST2) In step ST2, the signal information acquisition unit 113 acquires signal information of the microwave to be irradiated. The signal information includes information on the frequency, phase, and amplitude of the microwave, information from the tuner 13, and information on the power used for heating from the power sensor 118.

[0050] Furthermore, in step ST2, the temperature information acquisition unit 119 acquires temperature information of the object to be heated inside the heating furnace 14 from the temperature sensor 15.

[0051] (Step ST3) In step ST3, the signal information acquisition unit 113 stores the acquired signal information in the information storage unit 114.

[0052] Furthermore, in step ST3, the temperature information acquisition unit 119 stores the acquired temperature information in the information storage unit 114.

[0053] (Step ST4) In step ST4, the calculation unit 115 calculates the theoretical temperature of the object to be heated after microwave irradiation. The theoretical temperature of the object to be heated is calculated using the above formula (1).

[0054] (Step ST5) In step ST5, the inference unit 116 uses a learning model for inferring the temperature distribution of the object to be heated from the information of the object to be heated and the theoretical temperature value to infer the temperature distribution of the object to be heated from the information of the object to be heated used in the calculation by the calculation unit 115 and the theoretical temperature value calculated by the calculation unit 115.

[0055] (Step ST6) In step ST6, the inference unit 116 obtains the inferred temperature value at the temperature measurement point by the temperature sensor 15 from the inferred temperature distribution, and outputs the difference between this inferred temperature value (estimated result) and the actual temperature measured by the temperature sensor 15.

[0056] (Step ST7) In step ST7, the control variable calculation unit 117 determines whether the temperature inferred value and the temperature measured value match. Specifically, it determines whether the difference output by the inference unit 116 is 0 or not. If the two match, that is, if the difference is 0, the process proceeds to step ST11. On the other hand, if the two do not match, that is, if the difference is not 0, the process proceeds to step ST8.

[0057] (Step ST8) In step ST8, the control variable calculation unit 117 calculates the control variable based on the temperature difference ΔT obtained by the inference unit 116. The calculation of the control variable may be performed, for example, by table referencing.

[0058] (Step ST9) In step ST9, the control unit 112 controls the signal generator 12 and the tuner 13 according to the control amount calculated by the control amount calculation unit 117. In the case where the control unit 112 is not provided, the control amount calculation unit 117 may output only the phase shift amount to the phase shifter 17.

[0059] (Step ST10) In step ST10, the temperature sensor 15 measures the current temperature of the object to be heated. The measured temperature is stored in the information storage unit 114 via the temperature information acquisition unit 119.

[0060] (Step ST11) In step ST11, the calculation unit 115 determines whether the current temperature obtained via the temperature information acquisition unit 119 has reached the target temperature obtained in step ST1. If the current temperature has not reached the target temperature, the process returns to step ST2, and the flow from step ST3 to step ST11 is repeated. If the current temperature has reached the target temperature, the process ends.

[0061] <Note> Some aspects of the various embodiments described above are summarized below.

[0062] (Note 1) The microwave control device according to Note 1 comprises: a calculation unit (115) that calculates a theoretical temperature value of a heated object from the amount of heat absorbed by the heated object to be heated by microwave irradiation and heated object information including the specific heat and mass of the heated object; and an inference unit (116) that uses a learning model for inferring the temperature distribution of the heated object from the heated object information and the theoretical temperature value to infer the temperature distribution of the heated object from the heated object information used in the calculation by the calculation unit and the theoretical temperature value calculated by the calculation unit.

[0063] (Note 2) The microwave control device according to Note 2 is the microwave control device described in Note 1, further comprising a temperature information acquisition unit (118) that acquires the actual temperature value at a temperature measurement location which is part of the object to be heated, and the inference unit acquires the temperature inference value at the temperature measurement location from the inferred temperature distribution and outputs the difference between the temperature inference value and the actual temperature value.

[0064] (Note 3) The microwave control device according to Note 3 is the microwave control device described in Note 2, further comprising a control amount calculation unit (117) that calculates a control amount for irradiating microwaves according to the difference.

[0065] (Note 4) The microwave control device according to Note 4 is a microwave control device described in any one of Notes 1 to 3, further comprising a setting information acquisition unit (111) for acquiring the information of the object to be heated.

[0066] (Note 5) The microwave control device according to Note 5 is the microwave control device described in Note 4, wherein the setting information acquisition unit further acquires the relative permittivity, relative permeability, and conductivity of the object to be heated.

[0067] (Note 6) The microwave control device according to Note 6 is a microwave control device described in any one of Notes 1 to 5, further comprising a signal information acquisition unit (113) that acquires signal information including the frequency of the microwave.

[0068] (Note 7) The microwave control device according to Note 7 is a microwave control device described in any one of Notes 1 to 6, wherein the calculation unit calculates the amount of heat absorbed by the object to be heated using the relative permittivity, relative permeability, conductivity and frequency.

[0069] (Note 8) The microwave heating apparatus according to Note 8 comprises a microwave control device described in any one of Notes 1 to 7, a microwave irradiation device that irradiates by oscillating microwaves according to a controlled amount, and a heating furnace (14) that irradiates with the oscillating microwaves.

[0070] (Note 9) The microwave heating apparatus according to Note 9 is the microwave heating apparatus described in Note 8, further comprising a power sensor for measuring the power used to heat the object to be heated.

[0071] (Note 10) The microwave heating apparatus according to Note 10 is a microwave heating apparatus described in either Note 8 or 9, further comprising a temperature sensor, which is placed in the heating furnace and measures the temperature of the object to be heated.

[0072] (Note 11) The microwave control method performed by the microwave control device according to Note 11 comprises: a step (ST4) of calculating a theoretical temperature value of a heated object from the amount of heat absorbed by the heated object to be heated by microwave irradiation and heated object information including the specific heat and mass of the heated object; and a step (ST5) of inferring the temperature distribution of the heated object from the heated object information used in the calculation and the calculated theoretical temperature value, using a learning model for inferring the temperature distribution of the heated object from the heated object information and the theoretical temperature value.

[0073] (Note 12) The microwave control program according to Note 12 causes the computer to perform the following functions: a function to calculate the theoretical temperature of the object to be heated from the amount of heat absorbed by the object to be heated by microwave irradiation and the object information including the specific heat and mass of the object to be heated; and a function to infer the temperature distribution of the object to be heated from the object information used in the calculation and the calculated theoretical temperature, using a learning model for inferring the temperature distribution of the object to be heated from the object information and the theoretical temperature.

[0074] Furthermore, it is possible to combine embodiments, or to modify or omit each embodiment as appropriate.

[0075] The microwave control technology disclosed herein can be used as a microwave control device for heating industrial products such as plastics. Furthermore, the microwave control technology disclosed herein may be applied to household microwave ovens.

[0076] 1 (1A) Microwave heating device, 11 (11A) Microwave control device, 12 Signal generator, 13 Tuner, 14 Heating furnace, 15 Temperature sensor, 16 Signal source, 17 Phase shifter, 18 Amplifier, 100a Processing circuit, 100b Processor, 100c Memory, 111 Setting information acquisition unit, 112 Control unit, 113 (113A) Signal information acquisition unit, 114 Information storage unit, 115 Calculation unit, 116 Inference unit, 117 Control quantity calculation unit, 118 Power sensor, 119 Temperature information acquisition unit.

Claims

1. A microwave control device comprising: a calculation unit that calculates a theoretical temperature value of an object to be heated by microwave irradiation from the amount of heat absorbed by the object to be heated and information about the object to be heated, including the specific heat and mass of the object to be heated; and an inference unit that uses a learning model for inferring the temperature distribution of the object to be heated from the information about the object to be heated and the theoretical temperature value to be heated, and uses the information about the object to be heated used in the calculation by the calculation unit and the theoretical temperature value calculated by the calculation unit to infer the temperature distribution of the object to be heated.

2. A microwave control device according to claim 1, further comprising: a temperature information acquisition unit that acquires an actual temperature value at a temperature measurement location which is part of the object to be heated, wherein the inference unit acquires a temperature inference value at the temperature measurement location from the inferred temperature distribution and outputs the difference between the temperature inference value and the actual temperature value.

3. A microwave control device according to claim 2, further comprising a control amount calculation unit that calculates a control amount for irradiating microwaves according to the difference.

4. A microwave control device according to any one of claims 1 to 3, further comprising a setting information acquisition unit for acquiring the information of the object to be heated.

5. The microwave control device according to claim 4, wherein the setting information acquisition unit further acquires the relative permittivity, relative permeability, and conductivity of the object to be heated.

6. A microwave control device according to claim 5, further comprising a signal information acquisition unit that acquires signal information including the frequency of the microwave.

7. The microwave control device according to claim 6, wherein the calculation unit calculates the amount of heat absorbed by the object to be heated using the relative permittivity, relative permeability, conductivity, and frequency.

8. A microwave heating apparatus comprising: a microwave control device as described in any one of claims 1 to 7; a microwave irradiation device that irradiates by oscillating microwaves according to a controlled amount; and a heating furnace that irradiates with the oscillating microwaves.

9. The microwave heating apparatus according to claim 8, further comprising a power sensor for measuring the power used to heat the object to be heated.

10. A microwave heating apparatus according to any one of claims 8 or 9, further comprising a temperature sensor disposed in the heating furnace for measuring the temperature of the object to be heated.

11. A microwave control method performed by a microwave control device comprising: a step of calculating a theoretical temperature value of an object to be heated by microwaves from the amount of heat absorbed by the object to be heated and information about the object to be heated, including the specific heat and mass of the object to be heated; and a step of inferring the temperature distribution of the object to be heated from the information about the object to be heated and the calculated theoretical temperature value, using a learning model for inferring the temperature distribution of the object to be heated from the information about the object to be heated and the theoretical temperature value.

12. A microwave control program that causes a computer to perform the following functions: a function to calculate a theoretical temperature of an object heated by microwaves from the amount of heat absorbed by the object and information about the object, including its specific heat and mass; and a function to infer the temperature distribution of the object from the information about the object used in the calculation and the calculated theoretical temperature, using a learning model for inferring the temperature distribution of the object from the information about the object and the theoretical temperature.

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