US20240093875A1

US20240093875A1 - Method for operating a cooking appliance, and cooking appliance

Info

Publication number: US20240093875A1
Application number: US18/256,644
Authority: US
Inventors: Helge Nelson; Katja HOLTKOETTER; Thorsten Baumgart; Horst Noeller
Original assignee: Miele und Cie KG
Current assignee: Miele und Cie KG
Priority date: 2020-12-11
Filing date: 2021-11-30
Publication date: 2024-03-21
Also published as: EP4259974A2; DE102020133133A1; WO2022122478A3; KR20230118903A; WO2022122478A2; CN116601438A

Abstract

A method for operating a cooking appliance having a cooking chamber for receiving a food to be cooked, an operating device for setting an operating mode of the cooking appliance, a heating device for heating the cooking chamber, and a control device for controlling at least the heating device such that a heating program is carried out after the operating mode has been set. The method includes: determining a loading state of the cooking chamber by a monitoring device after an operating mode of the cooking appliance has been set, determination of the loading state including at least one distinction as to whether the food to be cooked is located in the cooking chamber; and as a function of the determined loading state, selecting a heating program from a plurality of stored heating programs and carrying out the selected heating program.

Description

CROSS-REFERENCE TO PRIOR APPLICATIONS

This application is a U.S. National Phase application under 35 U.S.C. § 371 of International Application No. PCT/EP2021/083589, filed on Nov. 30, 2021, and claims benefit to German Patent Application No. DE 10 2020 133 133.9, filed on Dec. 11, 2020. The International Application was published in German on Jun. 16, 2022 as WO 2022/122478 A2 under PCT Article 21(2).

FIELD

The present invention relates to a method for operating a cooking appliance and to a corresponding cooking appliance having a cooking chamber for receiving a food to be cooked, an operating device for setting an operating mode of the cooking appliance, a heating device for heating the cooking chamber, and a control device for controlling at least the heating device in such a way that a heating programme is carried out after the operating mode has been set.

BACKGROUND

When preparing food, it is necessary in many cases to heat the cooking chamber to a certain temperature before use. One reason for this is that most recipes specify a fixed cooking time and cooking chamber temperature. However, many automatic cooking programmes also provide for the cooking process to start when the cooking chamber is preheated. A heating process can take a relatively long time—in particular, at higher target cooking chamber temperatures—which is perceived as inconvenient.
Various quick heating programmes are known from the prior art, in which, for example, the heating device is operated at the highest possible power—in particular, using all available heat sources—in order to achieve the shortest possible heating time of only a few minutes. It is recommended to carry out such a quick heating process before inserting the food to be cooked, since the food may otherwise be damaged. However, it is often happens that the food to be cooked is already in the cooking chamber at the start of a quick heating programme—for example, due to an operating error or the impatience of the user, which adversely affects the cooking result.

SUMMARY

In an embodiment, the present invention provides a method for operating a cooking appliance having a cooking chamber for receiving a food to be cooked, an operating device for setting an operating mode of the cooking appliance, a heating device for heating the cooking chamber, and a control device for controlling at least the heating device such that a heating program is carried out after the operating mode has been set, the method comprising: determining a loading state of the cooking chamber by a monitoring device after an operating mode of the cooking appliance has been set, the determining of the loading state comprising at least one distinction as to whether the food to be cooked is located in the cooking chamber; and as a function of the determined loading state, selecting a heating program from a plurality of stored heating programs and carrying out the selected heating program.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be described in even greater detail below based on the exemplary figures. The invention is not limited to the exemplary embodiments. Other features and advantages of various embodiments of the present invention will become apparent by reading the following detailed description with reference to the attached drawings which illustrate the following:

FIG. 1 shows a cooking appliance according to the invention;

FIG. 2 shows a programme flowchart of an embodiment of the method according to the invention.

DETAILED DESCRIPTION

In an embodiment, the present invention provides a method for operating a cooking appliance which allows an improved heating process and in particular minimises the risk of operating errors. In an embodiment, the present invention provides a corresponding cooking appliance.
The method according to the invention serves for operating a cooking appliance having a cooking chamber for receiving food. According to this invention, stoves, ovens, oven-combination devices with a steam cooking and/or microwave function are particularly suitable as cooking appliances. The cooking chamber can be closed in particular by a door which, when open, allows the insertion of the food to be cooked or access to the food to be cooked. The cooking appliance is equipped with an operating device for setting an operating mode of the cooking appliance. In this case, the operating device can be arranged physically on the device, but can also be detached therefrom in the form of a remote control or in the form of a portable device with suitable operating software. In its simplest form, an operating mode can be a target cooking chamber temperature for the cooking chamber interior—in particular, when the cooking appliance is equipped with only a single heating device. An operating mode can also be a combination of a target cooking chamber temperature and a heating type, or even a temperature and/or heating profile with various target cooking chamber temperatures and heating devices, which are switched in succession or in combination. The target cooking chamber temperature, the heating type, the temperature profile, and/or the heating profile can either be set by the user or be assigned in a programme memory to an automatic programme that can be selected by the user. An operating mode can also include additional heating-independent functions such as humidifying the cooking chamber, switching on a light, or turning a spit. Furthermore, the cooking appliance is equipped with a heating device for heating the cooking chamber. A heating device can be a radiant heating element such as a top heat or bottom heat heating element, but also a circulating air heater in which a fan distributes the radiant heat generated by an annular heating element in the cooking chamber, but can also comprise other types of heating such as microwave radiation or steam. A control device is used at least to control the heating device in such a way that a heating programme is carried out after the operating mode has been set. The control device can be a physical component of the cooking appliance, but can also be arranged in part in a portable device or on an external programme memory. The heating programme is part of a cooking programme and is generally carried out at the beginning of the programme. In particular, a programme is understood as a heating programme in which one or more heating devices are controlled for heating the cooking chamber—in particular, from an initial cooking chamber temperature below a predetermined target cooking chamber temperature to a target cooking chamber temperature. In particular, an initial cooking chamber temperature is a temperature which is present in the cooking chamber at the start of heating. For example, the initial cooking chamber temperature essentially corresponds to the temperature of the surroundings of the cooking appliance when the cooking appliance has not been operated for a long period of time. However, it can also be a higher temperature which is present, for example, due to the residual heat of a previous cooking process. The heating programme generally ends when the set cooking chamber temperature or the target cooking chamber temperature assigned to the programme is reached. However, it can also occur in the middle of a cooking programme, if the cooking programme includes cooling and reheating the cooking chamber. The method is characterised in that a loading state of the cooking chamber is determined by means of a monitoring device at least after an operating mode of the cooking appliance has been set. As a function of the determined loading state of the cooking chamber, a heating programme is then selected from a plurality of heating programmes—in particular, stored in the control unit—for heating the cooking chamber, and carried out. In this case, the determination of the loading state comprises at least distinguishing whether food to be cooked is located in the cooking chamber or not.
The method according to the invention makes it possible to automatically detect the loading state of the cooking chamber and to adapt the process of heating to the particular loading state. For example, the loading state can be classified at least as one of the two states, “food to be cooked present” or “food to be cooked not present”. This prevents incorrect operation, which would lead to a deterioration in the cooking result.
Preferably, the plurality of heating programmes comprises at least a heating programme with low heating power and a heating programme with high heating power, which is designed in particular as a quick heating programme. In this case, low heating power is understood to mean, in particular, heating using only the heat sources provided for the selected operating mode, or possibly also fewer heat sources. A high heating power is to be understood in particular as a quick heating programme in which more heat sources are used than are provided for the selected operating mode, and, preferably, essentially all available heat sources or heat sources which can be operated with the predetermined connection value of the cooking appliance. In particular, a quick heating programme is understood to mean a circulating air heater and a grill heater with a maximum available heating power.
Preferably, a quick heating programme is carried out under substantially maximum heating power only if the monitoring device has determined that there is no food in the cooking chamber. If, on the other hand, food to be cooked—in particular, food of a first class of food to be cooked—is already located in the cooking chamber, and such a food to be cooked is recognised by means of the monitoring device, a heating programme with low heating power that is gentle on the food is to be started automatically. It can also be signalled to the user that food to be cooked is located in the cooking chamber, so that the user can optionally remove the food to be cooked from the cooking chamber in order to carry out the quick heating programme. A food of a first class of food to be cooked is one which is more sensitive to heating with high heating power. In this case, they can be soufflés, bakery products, or similar foods. A list of foods of the first class of foods to be cooked can be stored in a memory of the monitoring device.
If the monitoring device detects the presence in the cooking chamber of a food of a second class of food to be cooked after an operating mode has been set, a heating programme with medium heating power is preferably executed by the control device. A heating programme with medium heating power is understood to mean a heating programme in which the heating power of the selected heating elements is lower than in a quick heating programme with maximum heating power, and higher than in a heating programme with low heating power. In particular, the heat sources and further heating elements provided for the selected operating mode are switched on, wherein the further heating elements are not operated with the maximum possible heating power, but preferably only with a proportion of 20 to 50% of the maximum possible heating power. Preferably, the circulating air heater is additionally operated as a further low-power heating element if it is not already selected as an operating mode. A list of foods of the second class of foods to be cooked can also be stored in a memory of the monitoring device. An essential feature of a food of the second class of food to be cooked is that it does not necessarily require a heating programme with low heating power, such as frozen food. In particular, a food to be cooked would then necessarily require a heating programme with low heating power if it could be damaged or otherwise negatively influenced by a heating process with a heating power in excess of this. In the following, such a food to be cooked is also referred to as a critical food to be cooked. In this way, it is possible to automatically detect whether or not a heating programme which is generally shorter in duration can be carried out at higher heating power. Preferably, the food to be cooked is first classified as “critical/non-critical” by evaluating at least one image captured by the image recording device—in particular, at least wherein the type of food to be cooked is determined. In the event that the food to be cooked is classified as critical, the heating programme with low heating power is preferably carried out. In the case that the food to be cooked is classified as non-critical, a moderate heating programme is carried out in which, in particular, more heat sources are used than those provided for the selected operating mode, but not all available heat sources, such as in a quick heating programme. In this way, the heating time can be reduced without damaging the food to be cooked. Whether a specific food to be cooked is critical or non-critical can be determined empirically and stored in a retrievable manner in the cooking appliance or for the cooking appliance. When determining whether a specific food to be cooked is critical or non-critical, in addition to the criterion of frozen or fresh, a quantity of food to be cooked, the presence of a container for food to be cooked, and/or the height position of a food carrier carrying the food to be cooked in the cooking chamber can be taken into account.
In particular, the monitoring device is suitable and designed to detect an absence of food to be cooked in the cooking chamber, even if empty food containers or accessories of the cooking appliance are located there without food to be cooked, such as, for example, grates, baking sheets, deep fryers, pans, and/or other food containers or food carriers.
The monitoring device can, for example, comprise a high-frequency sensor device which is suitable and designed for analysing high-frequency radiation transmitted into the cooking chamber and/or received from the cooking chamber and in particular to distinguish high-frequency radiation reflected from a cooking chamber which is not loaded with food to be cooked from a high-frequency radiation reflected from a cooking chamber loaded with food to be cooked. The high-frequency sensor device can be suitable and designed for generating high-frequency radiation and transmitting it into the cooking chamber.
The monitoring device preferably comprises at least one image recording device, wherein the determination of the loading state comprises the evaluation of at least one image of the cooking chamber recorded by means of the image recording device. An image of the cooking chamber provides particularly meaningful measurement data regarding its state, allowing a particularly accurate determination of the loading state of the cooking chamber. In particular, in the present case, an image is understood to mean any type of data set which is recorded by means of an optical sensor comprised by the image recording device which records data on the colour values of individual measuring points and/or measuring surfaces, and, in particular, provides said data for the purpose of evaluation. The colour value is in this case in particular understood to mean a coordinate of a colour in a multidimensional colour space (e.g., RGB, CIELAB, CIEYUV, etc.). Particularly in the case of cooking appliances which are already equipped with an image recording device, e.g., in the form of a camera directed into the cooking chamber, the method according to the invention can be implemented or retrofitted in a cost-effective manner—for example, by a simple software update.
The cooking appliance, the monitoring device, and/or the image recording device preferably has an evaluation device with which the recorded image of the cooking chamber is evaluated to determine the loading state. Alternatively or additionally, the evaluation can take place at least in part externally, e.g., on an external server or in a cloud, wherein it is possible to equip the cooking appliance, the monitoring device, and/or the image recording device with corresponding communications interfaces for this purpose. For example, in order to detect the presence of food in the cooking chamber, it is possible to distinguish whether the image shows either a cooking chamber floor, an empty baking sheet, an empty grill, and/or other empty accessories, or else at least also a food to be cooked. Furthermore, a food to be cooked detected in the cooking chamber can be classified in more detail on the basis of an evaluation of the image, wherein properties of the food to be cooked, such as the type of food to be cooked and/or the quantity of food to be cooked, are determined and, if necessary, taken into account during the heating process. For all purposes, several images recorded by the image recording device—in particular, periodically or at irregular time intervals—can also be evaluated. The evaluation preferably comprises comparing the image and/or one or more features of the image with references in a database—in particular, wherein a classification of the image and/or one or more of its features takes place by means of statistical and/or analytical methods, such as, for example, variance analysis and/or a (support vector) regression. Alternatively or additionally, the evaluation can comprise a classification of the image and/or of one or more features of the image on the basis of an artificial neural network—in particular, on the basis of an artificial neural network trained in advance with a plurality of references, and/or by means of deep learning. Following the evaluation, certain control signals for controlling the heating device can be transmitted to the control unit, depending upon the result of the evaluation.
In a preferred embodiment of the invention, determining the loading state of the cooking chamber comprises at least detecting in the cooking chamber a type of food to be cooked, a quantity of food to be cooked, a container for food to be cooked, and/or a height position of a food carrier carrying the food to be cooked. In this way, even more information about the conditions present in the cooking chamber is automatically detected and can be taken into account when selecting the heating programme. This information can be used, for example, to select a heating programme that is tailored to the respective loading situation and that at least in part reduces the negative effects upon the food to be cooked. To detect the height position of the food carrier, such as a grate, a baking sheet, etc., a loading level or insertion plane of the food carrier can be detected, for example. For example, if it is detected that a food carrier loaded with food to be cooked is arranged in the highest loading level and therefore close to a top heat source of the heating device, a heating programme could be selected and carried out in which the top heat source is not operated. Furthermore, e.g., in the case of smaller quantities of food to be cooked, a gentler heating programme can be set than in the case of large quantities of food to be cooked. In contrast, a heating programme can be carried out at higher heating power if it is detected that the food to be cooked is in a closed oven dish or in another closed food container.
In a further preferred embodiment of the invention, the determination of the loading state of the cooking chamber is carried out again as a function of an opening and subsequent closing of a cooking chamber door. Because a change in the loading state is generally caused by the cooking chamber door being open, the coupling of the determination of the loading state to an opening or closing process of the cooking chamber door ensures that the current loading state is always detected—in particular, without having to rely on continuous monitoring of the loading state. For this purpose, the cooking appliance is preferably equipped with a door contact switch or other door sensor. For example, the loading state can be determined after or upon completion of a certain period of time after the opening and/or closing of the cooking chamber door. If the loading state is changed, the heating programme may, if required, then be changed.
In a further preferred embodiment of the invention, the determined loading state of the cooking chamber is used to check the plausibility of programme steps of a control programme controlling the cooking appliance. For this purpose, the loading state determined by the monitoring device is stored in the control device. The check for plausibility of programme steps can thus take place directly without the need for the monitoring device to determine the loading state again. For example, it can thus be ensured that requests from the cooking appliance are output to the user only if they are plausible in the context of the current loading situation. In this way, the risk of operating errors is further reduced. A request to “insert food” should not be output if the food to be cooked is already in the cooking chamber, while a request to “remove food” is invalid if, for example, there is no food in the cooking chamber. The control programme can in particular be a heating programme. Furthermore, the control programme can be a cooking programme for the actual cooking of the food to be cooked and/or a follow-up programme to be carried out after the cooking programme.
The cooking appliance according to the invention comprises a cooking chamber for receiving food to be cooked, a heating device for heating the cooking chamber, and a control device for controlling at least the heating device. It is characterised in that it has a monitoring device for determining a loading state of the cooking chamber and is suitable and designed for carrying out a method as described herein.
In particular, the cooking appliance according to the invention has the same advantages as the method according to the invention.
It is expressly noted that the embodiments of the invention explained above, individually or also in any technically meaningful combination with one another, can each be combined with the subject matter of any of the independent claims.
Individual technical features of the exemplary embodiment described below can also in combination be combined with previously described exemplary embodiments and the features of the independent claims and any further claims to form subject matter according to the invention.
FIG. 1 shows a cooking appliance 2 according to the invention with a cooking chamber 4 for receiving a food to be cooked 6. An operating device 24 is used to set an operating mode of the appliance. In addition, a heating device for heating the cooking chamber 4 is provided, which in the present embodiment comprises a circulating air heater in the form of a fan 8, equipped with an annular heater, of a top heat heating element 10, and of a bottom heat heating element 12 below the cooking chamber floor. A control device 14 is used, among other things, to control the heating device. The cooking appliance 2 also has, as a monitoring device, an image recording device 16 in the form of a camera which is arranged outside an insulation of the cooking chamber 4 and can take images of the cooking chamber 4 through a transparent window.
In this embodiment, the control device 14 also serves as an evaluation device which is configured to evaluate the image taken of the cooking chamber 4 in order to determine the loading state. In this case, the determination of the loading state comprises distinguishing whether food to be cooked 6 is located in the cooking chamber 4 or not. The control device 14 controls the heating device on the basis of a heating programme for heating the cooking chamber 4, which was selected from a plurality of stored heating programmes as a function of the determined loading state. By automatically detecting the loading state and adapting the heating process to the respective loading state, it can be ensured that the heating does not have a negative effect on the cooking result. Alternatively or in addition to the use of the control device 14 as an evaluation device, the evaluation can take place at least in part externally—for example, on an external server or in a cloud.
Preferably, the evaluation device is suitable and designed for detecting, if required, a type of food to be cooked, a quantity of food to be cooked, a container for food to be cooked, and/or a height position h of the food carrier 18 in the cooking chamber 4 on the basis of the image taken of the cooking chamber 4. For example, if it is detected that the food carrier 18 loaded with food to be cooked 6 is arranged at the highest loading level and thus close to the top heat heating element 10, a specially adapted heating programme could be set and carried out, in which the top heat heating element 10 is not operated so as not to heat the food to be cooked 6 too much from above.
The evaluation device is preferably configured in such a way that, in the event that food to be cooked 6 was detected in the cooking chamber 4, a further distinction would be made as to whether the food to be cooked 6 located in the cooking chamber 4 requires a heating programme with low heating power, i.e., whether it is critical or non-critical. In this way, it is automatically detected whether a heating programme with higher heating power can be carried out and thus whether time can be saved or not.
In particular, the loading state of the cooking chamber 4 is again determined as a function of an opening and/or a closing of a cooking chamber door 20. For this purpose, the cooking appliance has a door sensor 22 which detects an opening and/or closing of a cooking chamber door 20. In this way, the current loading state can always be detected, without having to resort to ongoing monitoring of the cooking chamber 4.
FIG. 2 illustrates the sequence of an embodiment of the method according to the invention, as is carried out, for example, by the cooking appliance shown in FIG. 1 . First, an operating mode of the cooking appliance 2 is set (step S1), whereupon the loading state of the cooking chamber 4 is checked for the presence of food to be cooked 6 (step S2). If it is detected that there is no food to be cooked 6 in the cooking chamber 4, a quick heating programme is started using essentially all available heat sources (step S3). If, on the other hand, the presence of food to be cooked 6 is detected in the cooking chamber 6, a further check is made as to whether the food to be cooked 6 is critical, i.e., whether a heating process with low heating power is absolutely necessary (step S4). If this is the case, the heating program with low heating power, e.g., using only the heat sources provided for the operating mode set in step S1, is carried out (step S5). If, on the other hand, the food to be cooked 6 has been classified as non-critical, a moderate heating programme is carried out (step S6) in which, in particular, more heat sources are used than those provided for the selected operating mode, but not all available heat sources, such as in the quick heating programme.
If, during the heating process, a cooking chamber door 20 of the cooking appliance 2 is opened and/or closed (step S7), the above-described determination of the loading state (step S2 together with subsequent steps) is carried out again. As a result, the method according to the invention is even more reliable, because it is possible to react to a change in the loading state. For example, if no food to be cooked 6 is detected in the cooking chamber 4 before the start of the heating process, a quick heating programme can be started. If it should happen that, for example, due to an operating error during the ongoing quick heating programme, food to be cooked 6 is placed in the cooking chamber 4, this will be detected by the monitoring device. The quick heating programme can then be stopped before the food to be cooked 6 is damaged. Furthermore, a heating programme suitable for the food to be cooked 6 can be started for further heating.
Once the target cooking chamber temperature has been reached (step S8), the actually selected cooking programme can be started (step S9).
While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive. It will be understood that changes and modifications may be made by those of ordinary skill within the scope of the following claims. In particular, the present invention covers further embodiments with any combination of features from different embodiments described above and below. Additionally, statements made herein characterizing the invention refer to an embodiment of the invention and not necessarily all embodiments.
The terms used in the claims should be construed to have the broadest reasonable interpretation consistent with the foregoing description. For example, the use of the article “a” or “the” in introducing an element should not be interpreted as being exclusive of a plurality of elements. Likewise, the recitation of “or” should be interpreted as being inclusive, such that the recitation of “A or B” is not exclusive of “A and B,” unless it is clear from the context or the foregoing description that only one of A and B is intended. Further, the recitation of “at least one of A, B and C” should be interpreted as one or more of a group of elements consisting of A, B and C, and should not be interpreted as requiring at least one of each of the listed elements A, B and C, regardless of whether A, B and C are related as categories or otherwise. Moreover, the recitation of “A, B and/or C” or “at least one of A, B or C” should be interpreted as including any singular entity from the listed elements, e.g., A, any subset from the listed elements, e.g., A and B, or the entire list of elements A, B and C.

Claims

1. A method for operating a cooking appliance, having a cooking chamber for receiving a food to be cooked, an operating device for setting an operating mode of the cooking appliance, a heating device for heating the cooking chamber, and a control device for controlling at least the heating device in such that a heating program is carried out after the operating mode has been set, the method comprising:

determining a loading state of the cooking chamber by a monitoring device after an operating mode of the cooking appliance has been set, the determining of the loading state comprising at least one distinction as to whether the food to be cooked is located in the cooking chamber; and

as a function of the determined loading state, selecting a heating program from a plurality of stored heating programs and carrying out the selected heating program.

2. The method of claim 1, wherein the plurality of heating programs comprises at least one heating program with low heating power and one heating program with high heating power.

3. The method of claim 2, wherein the one heating program with high heating power is carried out when a loading state is determined in which no food to be cooked is located in the cooking chamber, and

wherein the one heating program with low heating power is carried out when a loading state is determined in which the food to be cooked of a first class of food to be cooked is located in the cooking chamber.

4. The method of claim 3, wherein a heating program with medium heating power is carried out when a loading state is determined in which the food to be cooked of a second class of food to be cooked is located in the cooking chamber.

5. The method of claim 1, wherein the determination of the loading state comprises evaluation of at least one image of the cooking chamber recorded by an image recording device comprising the monitoring device.

6. The method of claim 1, wherein, as a function of an opening and subsequent closing of a cooking chamber door, the loading state of the cooking chamber is again determined and, if necessary, a change of the heating program occurs when the loading state is changed.

7. The method of claim 1, wherein, at least when a loading state is determined in which no food to be cooked is located in the cooking chamber, the end of the selected and carried out heating program is displayed.

8. The method of claim 1, wherein the determined loading state of the cooking chamber is used to check a plausibility of program steps of a cooking program controlling the cooking appliance.

9. A cooking appliance, comprising:

a cooking chamber configured to receive a food to be cooked;

a heating device configured to heat the cooking chamber;

a control device configured to control at least the heating device; and

a monitoring device configured to determine a loading state of the cooking chamber and to carry out theft method of claim 1.