Systems and methods for controlling microwave heating cycles

Abstract

A microwave appliance provides safe heating of food products within a food container within a temperature selection tolerance, even though the temperature of the food container differs from the temperature of the food product. The temperature of the food product may be higher than that of the food container, especially for higher temperature settings on the food product. This document provides a control method for calculating a target temperature for the food container when the heating cycle is about to stop. The control method stops the heating cycle when the measured temperature of the food container reaches the target temperature. The temperature of the microwave cavity also affects the measured temperature of the food container. Therefore, the temperature of the microwave cavity can be used to determine the adjustment of the target temperature for the food container.

Description

[0001] Cross-references to related applications

[0002] This application claims the benefit of U.S. Provisional Application Serial No. 63 / 071,475, filed August 28, 2020, the disclosure of which is expressly incorporated herein by reference.

[0003] background

[0004] Typical microwave ovens lack safety features that allow for the use of sealed packaging while preventing breakage of the sealed packaging. Such sealed packaging may accidentally break due to prolonged microwave oven operation. Therefore, open, ventilated, or otherwise unsealed food containers or packaging are used in typical microwave ovens. Consequently, during use, a typical microwave oven may be exposed to food products that have spilled from open food containers.

[0005] Overview

[0006] A first aspect of this disclosure provides a microwave appliance comprising one or more microwave sources and a microwave chamber in electromagnetic communication with the one or more microwave sources. The microwave appliance includes a product holder configured to support a food container within the microwave chamber, and a temperature sensor configured to sense the temperature of the food container supported within the product holder. The microwave appliance includes a user interface configured to receive a temperature selection. The microwave appliance includes a controller in communication with the temperature sensor and the user interface, the controller being configured to determine a target temperature for the food container based on the temperature selection. The controller is configured to operate the one or more microwave sources to heat the food product in the food container until the temperature of the food container equals the target temperature of the food container.

[0007] In some embodiments of the first aspect of this disclosure, the controller is configured to determine a target temperature for the food container based on a model of experimental results, the model relating the temperature of the food container to the temperature of the food product within the food container.

[0008] In some embodiments of the first aspect of this disclosure, the food product is sealed inside a food container.

[0009] In some embodiments of the first aspect of this disclosure, the model is a second-order polynomial equation:

[0010]

[0011] Where Tc is the target temperature of the food container, Tp is the temperature selection, and each of X, Y, and Z is a constant determined based on experimental results.

[0012] In some embodiments of the first aspect of this disclosure, the microwave appliance further includes a product identification scanner that communicates with a controller and is configured to read identifiers on the food container. The controller is configured to determine product attributes of the food container based on the identifiers.

[0013] In some embodiments of the first aspect of this disclosure, the model includes attribute multipliers that scale the target temperature of the food container based on product attributes.

[0014] In some embodiments of the first aspect of this disclosure, the product attributes are selected from a group of product attributes consisting of: the type of food product, the type of packaging, the size of the packaging, and combinations thereof.

[0015] In some embodiments of the first aspect of this disclosure, the microwave appliance further includes a second temperature sensor configured to sense the temperature of the microwave chamber, wherein the model includes chamber temperature adjustment based on the temperature of the microwave chamber added to a target temperature of the food container.

[0016] In some embodiments of the first aspect of this disclosure, when the temperature of the microwave chamber is 22°C, the chamber temperature adjustment is 0°C; when the temperature of the microwave chamber is 85°C, the chamber temperature adjustment is 4°C; and for other temperatures of the microwave chamber, the chamber temperature adjustment is linearly extrapolated between these two.

[0017] In some embodiments of the first aspect of this disclosure, the controller is configured to operate the one or more microwave sources to heat the food product in the food container to a temperature within a selected tolerance, wherein the tolerance is + / - 5%.

[0018] A second aspect of this disclosure provides a method for operating a microwave appliance. The method includes receiving a temperature selection from a user interface. The method includes determining a target temperature for a food container based on the temperature selection. The method includes powering one or more microwave sources to heat food products in the food container within a microwave chamber. The method includes using a temperature sensor to sense the temperature of the food container. The method includes shutting off power to the one or more microwave sources when the temperature of the food container reaches the target temperature.

[0019] In some embodiments of the second aspect of this disclosure, a model based on experimental results is used to determine the target temperature of the food container, the model relating the temperature of the food container to the temperature of the food product inside the food container.

[0020] In some embodiments of the second aspect of this disclosure, the food product is sealed inside a food container.

[0021] In some embodiments of the second aspect of this disclosure, the model is a second-order polynomial equation:

[0022]

[0023] Where Tc is the target temperature of the food container, Tp is the temperature selection, and each of X, Y, and Z is a constant determined based on experimental results.

[0024] In some embodiments of the second aspect of this disclosure, the method further includes identifying the food container based on scanning an identifier on the food container using a product identification scanner. The method further includes determining the product attributes of the food container based on the identifier.

[0025] In some embodiments of the second aspect of this disclosure, the model includes attribute multipliers that scale the target temperature of the food container based on product attributes.

[0026] In some embodiments of the second aspect of this disclosure, the product attributes are selected from a group of product attributes consisting of: the type of food product, the type of packaging, the size of the packaging, and combinations thereof.

[0027] In some embodiments of the second aspect of this disclosure, the method further includes using a second temperature sensor to sense the temperature of the microwave chamber. The model includes chamber temperature adjustment based on the temperature of the microwave chamber added to a target temperature of the food container.

[0028] In some embodiments of the second aspect of this disclosure, when the temperature of the microwave chamber is 22°C, the chamber temperature adjustment is 0°C; when the temperature of the microwave chamber is 85°C, the chamber temperature adjustment is 4°C; and for other temperatures of the microwave chamber, the chamber temperature adjustment is linearly extrapolated between these two.

[0029] In some embodiments of the second aspect of this disclosure, the food product in the food container is heated to a temperature within a selected tolerance, wherein the tolerance is + / - 5%.

[0030] These and other features will become clearer from the following detailed description taken in conjunction with the accompanying drawings and claims. Attached Figure Description

[0031] To gain a more complete understanding of this disclosure, reference is now made to the following brief description taken in conjunction with the accompanying drawings and specific embodiments, wherein similar reference numerals denote similar parts.

[0032] Figure 1 This is a front view of a microwave appliance used to heat packaged food products to a desired temperature.

[0033] Figure 2 It is a 3D diagram of a microwave appliance, in which the door is open.

[0034] Figure 3 This is a three-dimensional view of the left side of the microwave appliance, where the microwave inlet panel has been removed.

[0035] Figure 4 This is a 3D view of the right side of the microwave appliance, where the electronic components have been removed from the panel.

[0036] Figure 5 This is a block diagram of the microcontroller assembly of a microwave appliance.

[0037] Figure 6 This is a block diagram of the computer system for microwave appliances.

[0038] Figure 7 It is a flowchart of a control algorithm for a heating cycle executed by a microwave appliance.

[0039] Figures 8A-8E It is a graph that plots experimental data and established trend lines related to the temperature of packaging materials for various products and the product temperature.

[0040] Figure 9 Exemplary computer systems suitable for implementing several embodiments of this disclosure are shown. Detailed Implementation

[0041] It should be understood from the outset that although illustrative implementations of one or more embodiments are shown below, the disclosed systems and methods can be implemented using any number of techniques, whether currently known or existing. This disclosure should in no way be limited to the illustrative implementations, drawings, and techniques shown below, but modifications can be made within the full scope of the appended claims, together with their equivalents. The use of the phrase “and / or” indicates that any one or any combination of the options in the list may be used. For example, “A, B, and / or C” means “A”, or “B”, or “C”, or “A and B”, or “A and C”, or “B and C”, or “A and B and C”.

[0042] This document discloses a microwave appliance for facilitating reliable and efficient heating of packaged food products. The microwave appliance includes a temperature sensor configured to sense the temperature of the packaged food product. In some embodiments, the temperature sensor is a non-contact temperature sensor configured to sense the temperature of the packaged food product from outside the microwave chamber. Using a non-contact temperature sensor prevents interaction between the temperature sensor and the microwave radiation used when heating the packaged food product. For example, the temperature sensor may be an infrared temperature sensor arranged to sense infrared radiation emitted by the packaged food product. In another example, an ultrasonic sensor may be used to sense the temperature of the packaged food product. Other contact-based or non-contact temperature sensors may also be used.

[0043] Unlike the time-based operation of traditional microwave appliances, the operation of the disclosed microwave appliance can be based on a measured temperature of the packaged food product determined by a temperature sensor. During use, the consumer can select the desired product temperature. The desired product temperature can be an absolute temperature input (e.g., 52°C) received via an input on the user interface, or a relative temperature input (e.g., ambient, hot, very hot) received via an input on the user interface. The relative temperature input can be configured by a technician to a specific setpoint (e.g., ambient selection corresponds to 25°C, hot selection corresponds to 55°C, etc.). Temperature-based operation of the microwave appliance can be used with packaged food products of various sizes and types while ensuring that the product does not overheat during use. Furthermore, packaged food products can be reheated, or partially filled packaged food products can be safely heated to the desired product temperature. The maximum operating time can also be used as fault protection against temperature sensor malfunction.

[0044] However, the temperature of the food container is not an accurate measurement of the food product contained within it (e.g., beverages, soups, etc.). The temperature of the food product may be higher than the temperature of the food container, especially for higher temperature settings on the food product. This paper provides a control method for calculating the target temperature of the food container when the heating cycle is about to stop. The control method stops the heating cycle when the measured temperature of the food container reaches the target temperature of the food container. The control method results in the final food product temperature being within the tolerance (e.g., + / - 5%) of the temperature selected by the consumer on the user interface at the start of the heating cycle.

[0045] The control method uses test data of various categories and volumes of food products (e.g., beverages) to be heated in a microwave appliance to determine relevant values ​​specific to a particular food container placed within the microwave appliance. The control method uses a lookup table with relevant values ​​for different combinations of food product attributes to calculate a target temperature for the food container. In some embodiments, the calculation is based on a second-order polynomial equation relating the measured temperature of the food container to the temperature of the food product contained within, based on experimental data. The temperature of the microwave cavity also affects the measured temperature of the food container. Therefore, the temperature of the microwave cavity can be used to determine adjustments to the target temperature of the food container.

[0046] Examples of microwave appliances suitable for heating sealed food product containers are described in WO 2020 / 061049, entitled "Packaged Food Product Microwave System and Method," which is incorporated herein by reference in its entirety. See below for further details. Figure 1-6 A brief description of the microwave appliance is provided. This disclosure contemplates other microwave appliances suitable for the systems and methods described herein.

[0047] Figure 1-4 Various views of a microwave appliance 100 suitable for heating packaged food products to a desired temperature. Figure 1 This is a front view of microwave appliance 100, showing door 102 and user interface 104. Door 102 includes a window 112 for accessing user interface 104 when door 102 is closed.

[0048] Figure 2 This is a perspective view of microwave appliance 100, where door 102 is open. Door switch 532 can be positioned on the front surface of the body 123 of microwave appliance 100 or on door 102 and provides a signal indicating the position of door 102 (e.g., open or closed). Retainer 118 is positioned on the door and is sized and shaped to receive a sealed food container 120, such as a food or beverage container. Figure 2 In the example shown, food container 120 is a beverage bottle. Food container 120 can be made of plastic (e.g., polyethylene terephthalate, high-density polyethylene, etc.), glass, ceramic, foil-free cardboard boxes, etc. A retainer 118 is positioned on door 102 to hold food container 120 within microwave cavity 114 when door 102 is closed. For example, when door 102 is rotated to the closed position, retainer 118 passes through an opening in microwave cavity 114 to be positioned therein.

[0049] When door 102 is closed, reactive choke 116 is positioned on door 102 and around retainer 118 around the periphery of the opening in microwave cavity 114. Reactive choke 116 prevents microwave radiation from passing through door 102 during use. One or more product presence detectors 122 are positioned on door 102 around product retainer 118 and are configured to confirm whether food container 120 is located within product retainer 118. The product presence detectors 122 may be optical sensors or acoustic rangefinders for detecting the presence of food container 120 in product retainer 118. Multiple product presence detectors 122 can be used to ensure detection of food containers 120 of various sizes. Multiple product presence detectors 122 can also be used to verify the size of food container 120.

[0050] User interface 104 is positioned on the body 123 of microwave appliance 100. For example, user interface 104 is positioned on the front surface of the body 123 of microwave appliance 100. Figure 2 As shown, the front surface of the body of the microwave appliance 100 is the same surface that includes the opening in the microwave cavity 114. The user interface 104 may be a touchscreen user interface. The user interface 104 may include a graphics port 108 (such as an HDMI port) and a data port 110 (such as a Universal Serial Bus (USB) port). The graphics port 108 may supply graphic data for display on the user interface 104. The data port 110 may transmit touch or gesture input registered on the touchscreen. Other user interface elements may be used, and they may communicate via the data port 110 or another data port. For example, in a vending machine environment, a payment module may be additionally present to facilitate receiving payments and unlocking the door 102.

[0051] The product label scanner 124 is positioned on the body 123 of the microwave appliance 100. Figure 2 In the example shown, the product label scanner 124 is positioned below the user interface 104 and faces the product holder 118 when the door 102 is open. The product label scanner 124 may be an optical scanner (such as a barcode reader or camera) configured to read identifiers on the food container 120. In some embodiments, more than one barcode reader may be configured to read identifiers at multiple locations along the food container 120. Including multiple barcode readers facilitates the identification of different food containers 120 (where barcodes are located at different locations on the container 120) and takes into account containers 120 of different heights.

[0052] Product holder 118 may include an opening above its base, the size of which is configured to facilitate viewing an identifier on the food container 120 when it is placed within the product holder 118. For example, the identifier may be a barcode, symbol, quick response (QR) code, or other product identifier that encodes a Universal Product Code (UPC) or other product identifier. The size of product holder 118 may be configured to allow a user to rotate the food container 120 within the product holder 118 to facilitate scanning or otherwise reading the identifier on the food container 120. For example, by rotating the food container 120 within the product holder 118, the identifier may be located within the opening of the product holder 118 and within the field of view of the product label scanner 124.

[0053] In some embodiments, the product holder 118 includes a turntable at its base to facilitate easier rotation of the food container 120 within the product holder 118. The turntable may be motor-driven to automatically scan identifiers on the food container 120 within the product holder 118. The turntable motor may be activated when a door switch provides a signal indicating that the door 102 is open or after a predetermined delay after the door 102 is opened.

[0054] In some embodiments, the food container 120 may be scanned by the product identification scanner 124 before being inserted into the product holder 118. In such embodiments, the product presence detector(s) 122 may verify that the food container 120 has been inserted into the product holder 118 after being scanned by the product identification scanner 124.

[0055] Although the product label scanner 124 is described as an optical scanner in the example above, it can also be a wireless tag reader. For example, a wireless tag can be positioned on food container 120 (such as on a label or seal of the food container) and store an identifier of the food container 120. The wireless tag can be a radio frequency identification (RFID) tag, a Bluetooth Low Energy (BLE) tag, a Near Field Communication (NFC) tag, a beacon tag, etc. The wireless tag reader of the product label scanner 124 is configured to read the identifier of the food container 120 from the wireless tag on the food container 120.

[0056] Based on identifiers read from food container 120 by product identification scanner 124, microwave appliance 100 is configured to identify the type of food product being inserted into microwave appliance 100 (e.g., sugary carbonated beverages, sugar-free carbonated beverages, fruit juice beverages, tea, coffee, smoothies, dairy beverages, yogurt products, etc.), packaging type (e.g., PET carbonated beverage bottles, aluminum cans, aluminum bottles, hot-fill PET beverage bottles, aseptic PET beverage bottles, etc.), and / or packaging size (e.g., 20 fl. oz. packages, 12 fl. oz. packages, 8 fl. oz. packages, etc.). Based on the identification of the inserted food product type, microwave appliance 100 can identify the dielectric constant and / or conductivity of the food product and adjust the operation of the microwave appliance accordingly. For example, the power level of microwave appliance 100 can be adjusted based on the dielectric constant and / or conductivity of the food product. In response to reading the identifier, the microwave appliance 100 may access a local database or a network-accessible database that provides one or more tables or other logical structures that associate the identifier with the type of food product, packaging type, packaging size, dielectric constant of the food product, and / or conductivity of the food product.

[0057] The main body 123 of the microwave appliance 100 includes an electronics access panel 126 and a microwave access panel 132. The electronics access panel 126 is positioned on the right side surface of the main body 123 of the microwave appliance 100. The electronics access panel 126 includes a fan vent 128 and a duct vent 130, which are configured to facilitate air exchange with the surrounding environment to cool the microwave appliance 100. The microwave access panel 132, on the opposite side of the microwave appliance 100, on the left side surface of the main body 123, also includes a fan vent (not shown) and a duct vent (not shown).

[0058] Figure 3 This is a left perspective view of microwave appliance 100, with microwave entry panel 132 removed. Microwave entry panel 132 provides an entrance to microwave compartment 133, which has microwave components of microwave appliance 100. Figure 4 This is a right-side perspective view of microwave appliance 100, with the electronics access panel 126 removed. The electronics access panel 126 provides access to the electronics compartment 135. The microwave compartment 133 and the electronics compartment 135 are separated by a partition wall 134.

[0059] Microwave compartment 133 includes a microwave chamber 136 that provides an enclosed volume for receiving retainer 118. Microwave chamber 136 includes surfaces within it that reflect microwave radiation. For example, the sides of microwave chamber 136 may be made of a metal such as aluminum or steel. Microwave chamber 136 may include an electric field detector 538 for measuring the electric field within microwave chamber 136. Electric field detector 538 can be used to estimate the product volume within food container 120.

[0060] Microwave chamber 136 receives microwave radiation from one or more waveguides (such as waveguide 138 and waveguide 144). Waveguide 144 is in Figure 4 Shown in dashed lines to illustrate that waveguide 144 is located on the opposite side of spacer 134. Waveguide 138 on microwave chamber 136 is offset from waveguide 144 in the vertical direction. Magnetrons may be positioned around each of one or more waveguides. A first magnetron (not shown) is positioned around waveguide 138 for supplying microwave radiation to waveguide 138. The first magnetron includes an antenna located within waveguide 138. Waveguide 138 is configured to guide received microwave radiation along a first surface of microwave chamber 136 into microwave chamber 136. Similarly, a second magnetron (not shown) is positioned around waveguide 144 for supplying microwave radiation to waveguide 144. The second magnetron includes an antenna located within waveguide 144. Waveguide 144 is configured to guide received microwave radiation along a second surface of microwave chamber 136 into the second surface of microwave chamber 136.

[0061] Although two magnetrons are disclosed, more or fewer magnetrons can be used. Additional waveguides can be provided for each such additional magnetron. Providing additional magnetrons enables the creation of more complex standing wave modes to ensure robust coupling with a wider variety of food products in the food containers 120.

[0062] In some implementations, depending on the product identified by the product identification scanner 124, the power level of one or more magnetrons can be adjusted or one or more magnetrons can be turned off during use. For example, because waveguide 138 introduces microwave radiation into microwave chamber 136 at a higher position than waveguide 144, the first magnetron can be reduced or turned off during use if a short bottle or other food container 120 is placed in product holder 118.

[0063] Although Figure 3 The example shown provides waveguides 138, 144 for supplying microwave radiation to microwave chamber 136 from the opposite side of microwave chamber 136, but other configurations may be used. In some embodiments, a solid-state microwave source may be used instead of one or more magnetrons.

[0064] Microwave compartment 133 also includes a first magnetron power source 154 and a second magnetron power source 156 for powering magnetrons positioned around waveguides 138 and 144. Magnetron power sources 154 and 156 can be half-wave voltage doublers, inverters, or switch-mode power sources. Other power source types can also be used.

[0065] Temperature sensor 162 is positioned around the bottom surface of microwave chamber 136 and configured to measure the temperature of food container 120 in product holder 118 when door 102 is closed. In various embodiments, temperature sensor 162 may be positioned elsewhere to sense the temperature of food container 120. Temperature sensor 162 may be a non-contact temperature sensor configured to sense the temperature of packaged food product from outside the microwave chamber. Using a non-contact temperature sensor prevents interaction between the temperature sensor and the microwave radiation used to heat the food product in food container 120. For example, temperature sensor 162 may be an infrared temperature sensor arranged to sense infrared radiation emitted by the food product in food container 120. In another example, an ultrasonic sensor may be used to sense the temperature of packaged food product. Other contact-based or non-contact temperature sensors may be used. In some embodiments, an additional temperature sensor (not shown) may be positioned to measure the temperature within microwave cavity 114.

[0066] Food container 120 can have various shapes and sizes and product labels in different locations. The product label can isolate or otherwise affect the temperature readings of food container 120 obtained by temperature sensor 162. However, the base of food container 120 generally has less variation or variability, particularly at the center of the base. For example, beverage containers typically have a flat or petal-shaped base. Even with a petal-shaped base, the center of the beverage container base is generally uniform. Furthermore, product labels are rarely located on the base of food container 120.

[0067] When door 102 is closed, temperature sensor 162 is positioned facing the bottom of product holder 118. The bottom of product holder 118 may include a hole or opening through which temperature sensor 162 can view the bottom of food container 120. Measuring temperature from the bottom of food container 120 allows for accurate sensing of temperatures across a wider range of packaging types, regardless of packaging size, shape, or product label placement. Temperature can also be measured from other locations on food container 120, such as along the sidewalls, the lid, or other locations on the food container.

[0068] like Figure 4As best shown, the electronics compartment 135 includes a computer system 600 and a microcontroller assembly 500. A port access door 170 is located on the rear surface of the body 123 of the microwave appliance 100 to provide access to one or more input / output (I / O) ports on the computer system 600. A partition wall 134 isolates the components in the electronics compartment 135 from the thermal and electromagnetic noise generated by the components in the microwave compartment 133.

[0069] Figure 5 This is a block diagram of the microcontroller assembly 500 of the microwave appliance 100. The microcontroller assembly 500 includes a microcontroller 502 and an I / O interface board 504. The I / O interface board 504 is configured to receive various input signals and transmit the input signals to the microcontroller 502. The microcontroller 502 includes firmware 506 for processing the received input signals and generating an output control signal 508. The I / O interface board 504 supplies the output control signal 508 to components of the microwave compartment 133.

[0070] I / O interface board 504 also receives analog input from temperature sensor 162 and electric field detector 538. As described above, electric field detector 538 can be used to estimate the volume of product within food container 120. Additionally, electric field detector 538 can be used to verify that the electric field within microwave chamber 136 is within the expected range for normal operation. For example, if a metal food container 120 (such as a 12 oz. aluminum can) is inserted into microwave appliance 100, electric field detector 538 will sense a load below the expected or zero value. Simultaneously, product presence detector(s) 122 will sense the presence of food container 120 in product holder 118. Similarly, if no product is inserted into microwave appliance 100, electric field detector 538 will sense a load below the expected or zero value. Product presence detector(s) 122 will also sense the absence of any product in product holder 118. In either case, the operation of microwave appliance 100 can be prevented from being started or otherwise terminated when the electric field detector 538 senses a load value below the minimum permissible value indicated by the maximum permissible electric field threshold.

[0071] The maximum electric field threshold may correspond to the minimum volume of a given type of food product in a given food container 120. For example, for a given type of food product contained in a given food container 120, the maximum threshold may be a expected electric field reading corresponding to at least 5%, 10%, or 25% of the volume of the given food container 120.

[0072] Different materials have different dielectric constants and electrical conductivities, and therefore respond to microwave radiation coupling, absorption, or otherwise in different ways. For example, PET has a dielectric constant of about 1–3 ε', while water has a dielectric constant of about 80 ε'. Similarly, PET has a conductivity of about 10 ε'.-21 The conductivity of a saline solution is approximately 1-5 S / m, while that of a salt solution is approximately 1-5 S / m. Therefore, food products absorb microwave radiation more readily than containers that typically contain food products.

[0073] However, different food products have different electrical properties. Based on the electrical characteristics (e.g., dielectric constant and / or conductivity) of the food product inserted into the microwave chamber 136, such as readings from the product label scanner 124 and the detected electric field strength measured by the electric field detector 538, the volume of the food product can be estimated. Using the estimated volume of the food product inserted into the microwave chamber 136, the operation of the first magnetron power source 154 and / or the second magnetron power source 156 can be modified. For example, the power level of one or more of the magnetron power sources 154, 156 can be adjusted based on the estimated volume to avoid flash evaporation or otherwise reduce the risk of pressure buildup in the food container 120. Therefore, even a partially filled food container 120 can be safely heated to a target temperature in the microwave appliance 100.

[0074] The I / O interface board 556 also includes an output block 556 for supplying output control signals 508 to components in the microwave compartment 133. A first magnetron signal 554 is provided to a first magnetron MOSFET to turn a first power relay on or off. Similarly, a second magnetron signal 556 is provided to a second magnetron MOSFET to turn a second power relay on or off. When the first power relay is on, power is supplied to the first magnetron power source 154 and the corresponding fan. When the second power relay is on, power is supplied to the second magnetron power source 156 and the corresponding fan.

[0075] A first power control signal 558 is provided to a first magnetron power source 154 to modulate the power output from the first magnetron power source 154 to the first magnetron. A second power control signal 560 is provided to a second magnetron power source 156 to modulate the power output from the second magnetron power source 156 to the second magnetron. In some embodiments, the first power control signal 558 and the second power control signal 560 are pulse-width modulated control signals. The first power control signal 558 and the second power control signal 560 may be the same or different. For example, the first magnetron power source 154 and the second magnetron power source 156 may be operated to provide different power levels to their respective magnetrons.

[0076] Figure 6This is a block diagram of the computer system 600 of the microwave appliance 100. The computer system 600 includes an operating system 602 and one or more application programs 604 installed on the operating system 602. The computer 600 also includes a memory 606 with a file system for storing image, audio, and video data 608 for display on a user interface 104 or output from a speaker 168. One or more application programs 604 control the operation of components (such as a microcontroller 502) on a communication bus 610. An I / O interface 612 provides communication between one or more application programs 604 and the user interface 104, for example, supplying video or image data and receiving touch input from a touchscreen. A port 614, accessible via port access door 170, provides technicians with access for downloading usage and diagnostic data and uploading software updates for application(s) 604 or firmware 506. A database 616 can locally store usage and diagnostic data of the microwave appliance 100. For example, usage data may include how many times door 102 is opened, which products are scanned by product identification scanner 124, what temperature is selected on user interface 104 to heat the products, and the time of each of these events. Other usage data may be collected. Diagnostic data may include logs of inputs received on input block 516, analog input 544 and analog amplifier 542, and control signals 508. Other diagnostic data may be stored in database 616. A modem 618 may also be included for uploading usage and diagnostic data to a remote server (not shown) or for receiving software updates from a remote server. Other configurations and components are considered in this disclosure.

[0077] The operation of the microwave appliance 100 is based on a measured temperature of the food container 120, as determined by the temperature sensor 162. However, the temperature of the food container 120 is not an accurate measurement of the food product contained therein (e.g., beverage, soup, etc.). The temperature of the food product may be higher than the temperature of the food container 120, especially for higher temperature settings of the food product.

[0078] This document provides a control method for calculating the target temperature of a food container 120 when a heating cycle is about to stop (e.g., power is switched off to magnetron(s)). The control method stops the heating cycle when the measured temperature of the food container 120 reaches the target temperature. The control method results in the final food product temperature being within the tolerance (e.g., + / - 5%) of the temperature selected by the consumer on the user interface 104 at the start of the heating cycle.

[0079] Test data from various categories and volumes of food products (e.g., beverages) to be heated in microwave appliance 100 (e.g., water, tea, juice, coffee without cream / sweet, coffee with cream / sweet, etc.) are used to determine relevant values ​​specific to a particular food container 120 placed within microwave appliance 100. The control method uses a lookup table with relevant values ​​for different combinations of food product attributes to calculate a target temperature for food container 120. In some embodiments, the calculation is based on a second-order polynomial equation relating the measured temperature of food container 120 to the temperature of the food product contained therein, based on experimental data. The temperature of microwave cavity 114 also affects the measured temperature of food container 120. Therefore, the temperature of microwave cavity 114 can be used to determine adjustments to the target temperature of food container 120.

[0080] Figure 7 This is a flowchart of a control method 700 for a heating cycle performed by a microwave appliance 100. In various embodiments, the control method 700 is performed by a microcontroller assembly 500 (e.g., a microcontroller 502) and / or a computer system 600.

[0081] At 702, control method 700 identifies the food container 120 inserted into microwave appliance 100. For example, as described above, product label scanner 124 scans an identifier on the food container 120. Based on the identifier read from the food container 120 by product label scanner 124, microwave appliance 100 is configured to identify the type or category of the food product, the type of packaging, and / or the size or volume of the packaging.

[0082] In step 704, control method 700 receives user input regarding the product temperature of the food product within the food container 120 to be heated via user interface 104. The input product temperature can be an absolute temperature input (e.g., 52°C) received via an input terminal on user interface 104, or a relative temperature input (e.g., ambient, hot, very hot) received via an input terminal on user interface 104. The relative temperature input can be configured within microwave appliance 100 to correspond to a specific absolute temperature (e.g., heat selection corresponds to 55°C, etc.).

[0083] At 706, control method 700 determines a target temperature for the food container 120 in relation to the input product temperature received via user interface 104. The correlation between the temperature of the food container 120 and the temperature of the food product within the food container 120 is determined experimentally. While this paper provides an example of a second-order polynomial equation modeling the relationship between the temperature of the food container 120 and the temperature of the food product within the food container 120, other statistical or machine learning methods can be used to model the values ​​determined from experimental results.

[0084] Figures 8A-8E This is a graph showing experimental data and established trend lines relating packaging temperature to product temperature for various products. As shown, a non-linear relationship exists between packaging temperature and product temperature. Specifically, a small change in packaging temperature (IR Temp) was found to lead to a large change in product temperature (TC Temp). This non-linear effect was identified in part as being based on the increased pressure within the sealed food container 120 as it is heated. For example, the pressure within the food container 120 may increase to 8-22 psi during heating cycles, more typically around 14 psi. This pressure increase causes a non-linearity in the specific heat of water. Furthermore, the insulating properties of the food container 120 inhibit and delay heat transfer from the food product to the food container 120.

[0085] Based on experimental results, a second-order polynomial equation was determined to model the relationship between the temperature of the food container 120 and the temperature of the food product within a tolerance (e.g., + / - 5%) of the temperature selection received from the consumer on the user interface 104. The second-order polynomial equation is:

[0086]

[0087] Where Tc is the target temperature of food container 120, Tp is the target temperature of food product (e.g., temperature selection received via user interface 104), and each of X, Y, and Z is a constant determined based on experimental results.

[0088] In some examples, each of the constants X and Y is determined based on a second-order polynomial characterizing one or more physical properties of the identified food container 120 (e.g., the type or category of the identified food product, the type of packaging, the size or volume of the packaging, the estimated volume of the product based on the electric field detector 538, etc.). In specific examples where the estimated volume of the product detected within the food container 120 is a major contributing factor,

[0089] X = 6.67e -8 x 2 -2.96e -5 x + 0.0109, Equation (2)

[0090] Y = 5e -6 x 2 -0.00265x+0.8117, Equation (3)

[0091] Z = 29.6928, Equation (4)

[0092] Where x is the estimated volume of the product detected by the electric field detector 538. In some embodiments, x is a value combining one or more physical properties of the identified food container 120.

[0093] In some embodiments, the microwave appliance 100 can maintain a model for each product intended to be heated within the microwave appliance 100. However, this approach requires extensive testing for every combination of product, packaging type, and packaging volume. Instead of testing each combination individually, the microwave appliance 100 can maintain one or more property multipliers that model the effect of each property variation on the determination of the target temperature of the product container 120. In some embodiments, a single property multiplier may be used. In some embodiments, more than one property multiplier may be used. Multiplying each of the one or more property multipliers by the value of equation (1) yields:

[0094]

[0095] Where a m There are (multiple) attribute multipliers, and n is the number of attribute multipliers. Therefore, the (multiple) attribute multipliers scale the target temperature of the product container 120 based on (multiple) attributes of the product container determined based on the identifier read from the food container 120 by the product identification scanner 124.

[0096] For example, for beverage and food products, category multipliers could include a coffee multiplier of 1.2, a tea multiplier of 1.1, a juice multiplier of 1.07, a water multiplier of 1.25, an animal milk multiplier of 1.4, and a plant milk multiplier of 1.3. Similarly, packaging volume multipliers could include a 1.15 multiplier for beverage containers between 100 and 225 mL, a 1.25 multiplier for beverage containers between 226 and 350 mL, a 1.35 multiplier for beverage containers between 351 and 475 mL, and a 1.4 multiplier for beverage containers between 476 and 600 mL. This disclosure envisions other attribute multipliers and their values.

[0097] return Figure 7 In step 708, control method 700 optionally measures the temperature of microwave cavity 114. The temperature of microwave cavity 114 also affects the measured temperature of food container 120. Therefore, the temperature of microwave cavity 114 can be used to determine the adjustment of the target temperature of food container 120. As the temperature inside microwave cavity 114 increases, the temperature of food container 120 also increases based on the heat present inside microwave cavity 114. Therefore, the target temperature of food container 120 is reached faster than in the case of a lower temperature inside microwave cavity 114. Therefore, the chamber temperature adjustment can be added to equation (1) or equation (5) respectively to obtain:

[0098]

[0099]

[0100] Where C T This refers to chamber temperature adjustment. In one example, when the temperature of microwave cavity 114 is 22°C, the chamber temperature adjustment C... T It is 0℃; when the temperature of microwave cavity 114 is 85℃, the cavity temperature adjustment is 4℃, and for other temperatures of microwave cavity 114, the cavity temperature adjustment is linearly extrapolated between these two.

[0101] At 710, control method 700 initiates a heating cycle by switching power to magnetron(s). At 714, control method 700 uses temperature sensor 162 to receive a temperature measurement of food container 120. At 716, control method 700 determines whether the measured temperature of food container 120 is equal to a target temperature of food container 120. If not, control method 700 continues the heating cycle and returns to 712. Otherwise, if the measured temperature of food container 120 is equal to the determined target temperature of the food container, at 716, control method stops the heating cycle (e.g., switches off power to magnetron(s)). Thus, the product within food container 120 is heated to the input product temperature received at user interface 104, within tolerance (e.g., within + / - 5%).

[0102] It should be understood that the logical operations described in this paper with respect to various diagrams can be implemented as: (1) in a computing device (e.g., Figure 9 (1) A sequence of actions or program modules (i.e., software) implemented by a computer running on a computing device described herein; (2) interconnected machine logic circuits or circuit modules (i.e., hardware) within the computing device; and / or (3) a combination of software and hardware of the computing device. Therefore, the logical operations discussed herein are not limited to any particular combination of hardware and software. Implementation is a matter of choice depending on the performance and other requirements of the computing device. Therefore, the logical operations described herein are referred to differently as operations, structural devices, actions, or modules. These operations, structural devices, actions, and modules can be implemented using software, firmware, dedicated digital logic, and any combination thereof. It should also be understood that more or fewer operations than those shown in the figures and described herein may be performed. These operations may also be performed in a different order than those described herein.

[0103] refer to Figure 9This document illustrates an example computing device 1100 on which embodiments of the invention can be implemented. For example, the microwave appliance 100, user interface 104, microcontroller 502, and / or computer 600 described herein can each be implemented as a computing device, such as computing device 1100. It should be understood that the example computing device 1100 is merely one example of a suitable computing environment on which embodiments of the invention can be implemented. Optionally, computing device 1100 can be a well-known computing system, including but not limited to personal computers, servers, handheld or laptop devices, multiprocessor systems, microprocessor-based systems, networked personal computers (PCs), minicomputers, mainframe computers, embedded systems, and / or distributed computing environments comprising any of these systems or devices. Distributed computing environments enable remote computing devices connected to communication networks or other data transmission media to perform various tasks. In a distributed computing environment, program modules, applications, and other data can be stored on local and / or remote computer storage media.

[0104] In embodiments, computing device 1100 may include two or more computers communicating with each other to collaborate in performing tasks. For example, but not as a limitation, applications may be partitioned in a manner that allows concurrent and / or parallel processing of instructions from the application. Alternatively, data processed by the application may be partitioned in a manner that allows concurrent and / or parallel processing of different portions of the dataset by two or more computers. In embodiments, computing device 1100 may employ virtualization software to provide the functionality of multiple servers that are not directly integrated into multiple computers within computing device 1100. For example, virtualization software may provide twenty virtual servers on four physical computers. In embodiments, the functionality disclosed above may be provided by executing one and / or more applications in a cloud computing environment. Cloud computing may include providing computing services via network connectivity using dynamically scalable computing resources. Cloud computing may be supported at least in part by virtualization software. Cloud computing environments may be established by an enterprise and / or may be rented from third-party providers as needed. Some cloud computing environments may include cloud computing resources owned and operated by the enterprise as well as cloud computing resources rented and / or leased from third-party providers.

[0105] In its most basic configuration, the computing device 1100 typically includes at least one processing unit 1120 and system memory 1130. Depending on the exact configuration and type of the computing device, the system memory 1130 may be volatile (such as random access memory (RAM)), non-volatile (such as read-only memory (ROM), flash memory, etc.), or some combination of both. This most basic configuration in Figure 9The processing unit 1120 is shown in dashed line 1110. It can be a standard programmable processor necessary to perform arithmetic and logical operations required for the operation of the computing device 1100. Although only one processing unit 1120 is shown, multiple processors may exist. Therefore, while instructions may be discussed as being executed by a single processor, these instructions may be executed simultaneously, sequentially, or otherwise by one or more processors. The computing device 1100 may also include buses or other communication mechanisms for transmitting information among the various components of the computing device 1100.

[0106] The computing device 1100 may have additional features / functions. For example, the computing device 1100 may include additional storage devices, such as removable storage device 1140 and non-removable storage device 1150, including but not limited to disks or optical discs or magnetic tapes or optical strips. The computing device 1100 may also include (multiple) network connectors 1180 that allow the device to communicate with other devices (e.g., via the communication paths described herein). The (multiple) network connectors 1180 may take the form of modems, modem groups, Ethernet cards, Universal Serial Bus (USB) interface cards, serial interfaces, token ring cards, Fiber Distributed Data Interface (FDDI) cards, Wireless Local Area Network (WLAN) cards, radio transceiver cards (such as Code Division Multiple Access (CDMA), Global System for Mobile Communications (GSM), Long Term Evolution (LTE), Global Microwave Access Interoperability (WiMAX) and / or other air interface protocol radio transceiver cards), and other well-known network devices. The computing device 1100 may also have multiple input devices 1170, such as a keyboard, keypad, switch, dial pad, mouse, trackball, touchscreen, voice recognizer, card reader, paper tape reader, or other known input devices. It may also include multiple output devices 1160, such as a printer, video monitor, liquid crystal display (LCD), touchscreen display, monitor, speaker, etc. Additional devices may be connected to a bus to facilitate data communication among components of the computing device 1100. All these devices are well known in the art and need not be discussed in detail here.

[0107] Processing unit 1120 can be configured to execute program code encoded in a tangible computer-readable medium. A tangible computer-readable medium refers to any medium capable of providing data that causes computing device 1100 (i.e., the machine) to operate in a particular manner. Various computer-readable media can be used to provide instructions to processing unit 1120 for execution. Examples of tangible computer-readable media include, but are not limited to, volatile, non-volatile, removable, and non-removable media implemented in any method or technology for storing information such as computer-readable instructions, data structures, program modules, or other data. System memory 1130, removable storage device 1140, and non-removable storage device 1150 are examples of tangible computer storage media. Examples of tangible computer-readable recording media include, but are not limited to, integrated circuits (e.g., field-programmable gate arrays or application-specific integrated circuits), hard disks, optical disks, magneto-optical disks, floppy disks, magnetic tapes, holographic storage media, solid-state devices, RAM, ROM, electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROMs, digital universal disks (DVDs) or other optical storage devices, magnetic cassettes, magnetic tapes, disk storage devices or other magnetic storage devices.

[0108] The foundation of electrical and software engineering is that functionality, which can be implemented by loading executable software into a computer, can be translated into a hardware implementation using well-known design rules. Decisions between software-to-hardware implementation concepts typically depend on the stability of the design and the number of units to be produced, rather than any issues involved in the translation from the software domain to the hardware domain. Often, designs still subject to frequent changes may be preferred to be implemented in software because redeveloping a hardware implementation is more expensive than redeveloping a software design. Often, stable designs that will be mass-produced may be preferred to be implemented in hardware, such as with application-specific integrated circuits (ASICs), because hardware implementations may be less expensive than software implementations for mass production runs. Often, designs can be developed and tested in software and later transformed into an equivalent hardware implementation in an ASIC with hardwired software instructions using well-known design rules. Just as a machine controlled by a new ASIC is a specific machine or device, a computer programmed and / or loaded with executable instructions can also be considered a specific machine or device.

[0109] In an example implementation, processing unit 1120 may execute program code stored in system memory 1130. For example, a bus may transport data to system memory 1130, from which processing unit 1120 receives and executes instructions. Data received in system memory 1130 may optionally be stored on removable storage device 1140 or non-removable storage device 1150 before or after execution by processing unit 1120.

[0110] It should be understood that the various techniques described herein can be implemented in combination with hardware or software, or in combination thereof where appropriate. Therefore, the methods and apparatus of the currently disclosed subject matter, or certain aspects or portions thereof, can take the form of program code (i.e., instructions) embodied in a tangible medium (such as a floppy disk, CD-ROM, hard disk, or any other machine-readable storage medium), wherein, when the program code is loaded into and executed by a machine such as a computing device, the machine becomes an apparatus for practicing the currently disclosed subject matter. In the case of executing program code on a programmable computer, the computing device typically includes a processor, a storage medium readable by the processor (including volatile and non-volatile memory and / or storage elements), at least one input device, and at least one output device. One or more programs can be implemented, for example, by using an application programming interface (API), reusable controls, etc., or utilize the processes described in conjunction with the currently disclosed subject matter. Such programs can be implemented in a high-level program or an object-oriented programming language to communicate with a computer system. However, if desired, the programs can be implemented in assembly language or machine language. In any case, the language can be a compiled or interpreted language, and it can be combined with hardware implementations.

[0111] This document may describe embodiments of methods and systems with reference to block diagrams and flowcharts of methods, systems, apparatus, and computer program products. It will be understood that each block shown in the block diagrams and flowcharts, as well as combinations of blocks shown in the block diagrams and flowcharts, can be implemented by computer program instructions. These computer program instructions can be loaded onto a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute on the computer or other programmable data processing apparatus, create means for implementing the functions specified in one or more blocks of the flowchart.

[0112] These computer program instructions may also be stored in a computer-readable storage medium that can instruct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of writing comprising computer-readable instructions for implementing the functions specified in one or more blocks of a flowchart. The computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process, such that the instructions executing on the computer or other programmable apparatus provide steps for implementing the functions specified in one or more blocks of a flowchart.

[0113] Therefore, the blocks shown in the block diagrams and flowcharts support combinations of devices for performing a specified function, combinations of steps for performing a specified function, and program instruction devices for performing a specified function. It will also be understood that each block shown in the block diagrams and flowcharts, and combinations of blocks shown in the block diagrams and flowcharts, can be implemented by a dedicated hardware-based computer system or a combination of dedicated hardware and computer instructions that performs the specified function or steps.

[0114] Although several embodiments have been provided in this disclosure, it should be understood that the disclosed systems and methods may be embodied in many other specific forms without departing from the spirit or scope of this disclosure. These examples are to be considered illustrative rather than limiting and are not intended to be limited to the details given herein. For example, various elements or components may be combined or integrated into another system, or certain features may be omitted or not implemented.

[0115] Furthermore, without departing from the scope of this disclosure, the technologies, systems, subsystems, and methods described and illustrated as discrete or separate in the various embodiments may be combined or integrated with other systems, modules, technologies, or methods. Other items shown or discussed as directly connected or communicating with each other may be indirectly connected or communicating through an interface, device, or intermediate component, whether electrically, mechanically, or otherwise. Other examples of changes, substitutions, and modifications can be determined by those skilled in the art and may be made without departing from the spirit and scope of the disclosure herein.

Claims

1. A microwave appliance, comprising: One or more microwave sources; A microwave room, wherein the microwave room is electromagnetically connected to the one or more microwave sources; Product holder, the product holder being configured to support a food container in the microwave chamber; A temperature sensor configured to sense the temperature of the food container supported within the product holder; A user interface configured to receive temperature selection for the food product in the food container; The controller communicates with the temperature sensor and the user interface; A product label scanner, which communicates with the controller and is configured to read identifiers on the food container; as well as A second temperature sensor, configured to sense the temperature of the microwave chamber; The controller is configured to: The product attributes of the food container are determined based on the identifier; The target temperature of the food container is determined based on the temperature selection using a nonlinear model that uses experimental results. The nonlinear model correlates the temperature of the food container with the temperature of the food product inside the food container. Operate the one or more microwave sources to heat the food product in the food container until the temperature of the food container is equal to the target temperature of the food container; The model includes: Multiple constants, said multiple constants being based on the product attributes and the estimated volume of food in the food container as detected by an electric field detector in the microwave chamber; Attribute multipliers, which scale the target temperature of the food container based on the product attributes; and Chamber temperature adjustment, which is added to the target temperature of the food container based on the temperature of the microwave chamber; The product attributes are selected from the following product attribute groups: type of food product, type of packaging, size of packaging, and combinations thereof.

2. The microwave appliance as claimed in claim 1, wherein, The food product is sealed inside the food container.

3. The microwave appliance as described in claim 1, wherein, The model is a second-order polynomial equation: ， in Tc This is the target temperature of the food container. Tp The temperature selection is mentioned. X , Y and Z These are the constants determined based on the experimental results. a m It is the attribute multiplier, n It is the number of the attribute multipliers, and C T This refers to the adjustment of the chamber temperature.

4. The microwave appliance as claimed in claim 1, wherein, The chamber temperature adjustment added to the target temperature is defined as follows: When the temperature of the microwave chamber is 22°C, the chamber temperature is adjusted to 0°C; When the temperature of the microwave chamber is 85°C, the chamber temperature is adjusted to 4°C; and When the microwave chamber is at another temperature, the chamber temperature is adjusted based on a temperature linearly extrapolated between these two defined points.

5. The microwave appliance as claimed in claim 1, wherein, The controller is configured to operate the one or more microwave sources to heat the food product in the food container to a temperature within a selected tolerance, wherein the tolerance is + / - 5%.

6. A method of operating a microwave appliance, comprising: Receive temperature selections for food products from the user interface; The food container is identified by scanning the identifier on it using a product identification scanner. The product attributes of the food container are determined based on the identifier; The target temperature of the food container is determined based on the temperature selection using a nonlinear model that uses experimental results. The nonlinear model correlates the temperature of the food container with the temperature of the food product inside the food container. Power is supplied to one or more microwave sources to heat the food products in the food containers within the microwave chamber; A temperature sensor is used to sense the temperature of the food container; When the temperature of the food container reaches the target temperature, the power to one or more microwave sources is turned off; as well as The temperature of the microwave chamber is sensed using a second temperature sensor; The model includes: Multiple constants, said multiple constants being based on the product attributes and the estimated volume of food in the food container as detected by an electric field detector in the microwave chamber; Attribute multipliers, which scale the target temperature of the food container based on the product attributes; and Chamber temperature adjustment, which is added to the target temperature of the food container based on the temperature of the microwave chamber; The product attributes are selected from the following product attribute groups: type of food product, type of packaging, size of packaging, and combinations thereof.

7. The method of claim 6, wherein, The food product is sealed inside the food container.

8. The method of claim 6, wherein, The model is a second-order polynomial equation: ， in Tc This is the target temperature of the food container. Tp The temperature selection is mentioned. X , Y and Z These are the constants determined based on the experimental results. a m It is the attribute multiplier, n It is the number of the attribute multipliers, and C T This refers to the adjustment of the chamber temperature.

9. The method of claim 6, wherein, The chamber temperature adjustment added to the target temperature is defined as follows: When the temperature of the microwave chamber is 22°C, the chamber temperature is adjusted to 0°C; When the temperature of the microwave chamber is 85°C, the chamber temperature is adjusted to 4°C; and When the microwave chamber is at another temperature, the chamber temperature is adjusted based on a temperature linearly extrapolated between these two defined points.

10. The method of claim 6, wherein, The food product in the food container is heated to a temperature within the tolerance selected by the temperature selection, wherein the tolerance is + / - 5%.

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