EP2741011B1 - Cooking device - Google Patents

Description

The present invention relates to a cooking appliance, such as an oven, a microwave or a steamer. The invention also relates to a method for operating a cooking appliance.

A conventional cooking appliance has a cooking chamber for cooking food, a control device for carrying out a plurality of predetermined cooking programs and a user interface coupled to the control device for controlling the control device. The user can select a specific cooking program via the user interface. The control device then carries out the selected cooking program.

It is known to indicate the end of the cooking time to the user via a display on the cooking appliance when cooking food. Furthermore, methods for determining the remaining cooking time of the food are known. For example, such methods are described in the documents DE 103 27 861 B4 and EN 10 2004 049 927 A1 described. In these methods, the gradients of signal curves of gas concentrations in the cooking chamber can be evaluated in order to determine a remaining cooking time for cooking the food.

The DE 103 27 864 A1 relates to a method for contactless control of a cooking process in a cooking appliance and a cooking appliance for carrying out the method.

The EN 10 2010 060 821 A1 relates to a cooking appliance for determining at least one property of a cooking chamber atmosphere.

The EP 2 031 306 A1 discloses a method for cooking a food item in a cooking appliance having a cooking chamber, at least one heating device, a computing device, a storage device and at least one sensing device.

The EN 10 2007 040 316 A1 relates to a method for displaying a remaining cooking time during a cooking process in a cooking appliance.

The DE 103 00 465 A1 relates to a method for cooking food in a cooking chamber of a cooking appliance.

The EN 10 2005 011 304 A1 discloses a method and an associated oven for determining the food to be cooked.

The US 5 681 496 A relates to a device and a method for controlling a cooking device. The moisture content is measured using a moisture sensor within a cooking chamber.

The EN 10 2004 049927 A1 discloses a cooking appliance with a sensor designed as a carbon dioxide sensor or alternatively as an oxygen sensor, via which a gas concentration is detected. By comparing with reference value sets, parameter sets are selected from which an end of cooking time is calculated.

Against this background, one object of the present invention is to improve the determination of a remaining cooking time of the food in the cooking appliance.

According to the invention, a cooking appliance is proposed which has a cooking chamber for cooking food, an oxygen sensor arranged in the cooking chamber for determining a current signal curve of an oxygen concentration in the cooking chamber, a nitrogen sensor arranged in the cooking chamber for determining a current signal curve of a nitrogen concentration in the cooking chamber, a humidity sensor arranged in the cooking chamber for determining a current signal curve of a humidity concentration in the cooking chamber, a temperature sensor arranged in the cooking chamber for recording a heating curve of the cooking chamber, a memory in which a plurality of oxygen reference signal curves for the oxygen concentration in the cooking chamber, a plurality of nitrogen reference signal curves for the nitrogen concentration in the cooking chamber and a plurality of humidity reference signal curves for the humidity concentration in the cooking chamber are stored, and a control device which is set up to determine a remaining cooking time of the food by comparing the determined current signal curves with the plurality of stored reference signal curves and depending on the recorded heating curve, wherein the control device for this is designed to record the signal curves of the oxygen concentration, nitrogen concentration and moisture concentration in the cooking chamber determined by the sensors during cooking carried out by a user and to store the recorded signal curves in the memory as reference signal curves.

One advantage of determining the remaining cooking time according to the invention is that it can be determined or calculated very precisely. Furthermore, when determining the remaining cooking time according to the invention, no user input is required, such as the weight of the food to be cooked. Furthermore, the reference signal curves can be learned during operation of the cooking device, so that the determination of the remaining cooking time can be further refined during the lifetime of the cooking device and expanded to include a larger number of dishes.

By using the current heating curve to determine the remaining cooking time, its calculation can be made more precise.

By using a variety of different sensors to determine different gas concentrations, the calculation of the remaining cooking time can be further refined and improved.

By setting up the control device to record the signal curve of the gas concentration in the cooking chamber determined by the sensor during cooking carried out by a user and to store the recorded signal curve in the memory as a reference signal curve, the cooking appliance can learn adaptively and thus further improve the determination of the remaining cooking time.

In particular, the reference signal curve that has a minimal deviation from the current signal curve is selected. Each reference signal curve is assigned a total cooking time, from which the remaining cooking time can then be easily calculated depending on the cooking time already required. By determining the remaining cooking time, the user can estimate the end of the cooking process and prepare to be at the cooking device at the expected end of cooking in order to remove the food or dish from the cooking chamber.

The remaining cooking time refers to the time that is still needed to cook the food in the cooking chamber, especially with the currently set cooking program. At the start of cooking, the remaining cooking time and the total cooking time are the same.

In one embodiment, the cooking appliance has a display device which is designed to display the determined remaining cooking time to a user. The display device is designed, for example, as a touch-sensitive screen (touchscreen) and is integrated into a user interface.

The user interface is in particular coupled to the control device and designed to control the control device. The control device is designed to output a selected cooking program, the specific remaining cooking time and potentially other data relating to cooking to the user via the user interface. The user interface has, for example, input buttons and the touch-sensitive screen.

In a further embodiment, a specific total cooking time is assigned to the respective reference signal curve of the majority of reference signal curves. The control device is designed to use the comparison to select the reference signal curve with a minimum distance to the specific current signal curve and to determine the remaining cooking time as the difference between the total cooking time assigned to the selected reference signal curve and a start time of cooking. The cooking device preferably has a timer for recording the start time of cooking.

In a further embodiment, the control device is configured to calculate an average absolute deviation between the determined current signal waveform and each of the stored reference signal waveforms and to select the reference signal waveform with the calculated minimum average absolute deviation for determining the remaining cooking time.

In a further embodiment, the memory comprises a database for storing N reference signal waveforms. The database stores a data set for each of the N reference signal waveforms. The respective data set comprises a temporal Sequence of reference signal values of the gas concentration in the cooking chamber and an associated total cooking time for the food in the cooking chamber.

The following example illustrates the above embodiments for the reference signal curves and the determination of the remaining cooking time. The database includes - as explained above - the total cooking time for the respective reference signal curve. In addition, signal values are stored at selected times, e.g. 5 minutes, 6 minutes or the like, up to a predetermined end time, e.g. 20 minutes. The example extract from a database below includes three data sets for three curves k (k ∈ {1, 2, 3}). The control device measures the signal value at the times specified in the database, in this example at times 5, 6, 8, ... 20 minutes, and compares the current measured signal values with the values in the database. The number of data sets in the database is designated as N.

Structure of the database (example with N = 3 data records)

Curve No. k Cooking time in minutes F(t = 5 min) F(t = 6 min) F(t = 7 min) ... F(t = 19 min) F(t = 20 min) 1 30 4 5 7 ... 34 35 2 45 3 4 5 ... 23 23 3 60 3 3 5 ... 18 19

For each data set k, the controller calculates the mean absolute deviation MAA: $$\mathrm{MAA}\left(\mathrm{k}\right)={\displaystyle \sum _{\mathrm{t}=0}^{\mathrm{T}}\left|{\mathrm{F}}_{\mathrm{act}}(\left(\mathrm{t}\right)-{\mathrm{F}}_{\mathrm{k}}\left(\mathrm{t}\right)\right|}$$

The symbol "|x|" means the absolute value of the argument x: |x| = x for x ≥ 0; -x otherwise. F _act (t) is the current signal value at time t. F _k (t) is the signal value of curve no. k in the database at time t.

The controller looks for the smallest MAA(k) value. $$\mathrm{MAAmin}\left(\mathrm{kbest}\right)=\mathrm{Min}\left(\mathrm{<figure-callout\; id="1"\; label="MAA"\; filenames="imgf0001.png,imgf0002.png"\; state="\{\{state\}\}">MAA</figure-callout>}\left(1\right),\mathrm{<figure-callout\; id="2"\; label="MAA"\; filenames="imgf0001.png,imgf0002.png"\; state="\{\{state\}\}">MAA</figure-callout>}\left(2\right),\dots \mathrm{MAA}\left(\mathrm{N}\right)\right)$$

This means that curve no. kbest best fits the current signal curve. The remaining time displayed is then the total cooking time of the curve kbest stored in the database, minus the cooking time that has already elapsed.

The tables below show an extract from the above databases with the three data sets and an example of the current signal curve. For each point in time stored in the database, the absolute deviation is calculated from the current signal value minus the signal value of curve k in the database. The respective deviations are added up and shown in the MAA(k) column. The control device then determines the minimum of MAA(k). In the example below, this is found for curve k = 1. Consequently, curve k = 1 best fits the current signal curve. The total cooking time is therefore 30 minutes. At time t = 20 minutes, the remaining time is therefore calculated from the difference between 30 minutes and 20 minutes (30 minutes - 20 minutes = 10 minutes).

Database

k Cooking time F _k (5) F _k (6) F _k (7) F _k (19) F _k (20) 1 30 4 5 7 ... 34 35 2 45 3 4 5 ... 23 23 3 60 3 3 5 ... 18 19 Current signal curve: F _act (5) F _act (6) F _act (7) ... F _act (19) F _act (20) 4 4 5 ... 30 31 Calculation: Absolute deviations = |F _k - F _akt | MAA(k) k |F _k (5) - F _act (5)| |F _k (6) - F _act (6)| |F _k (7) - F _act (7)| ... |F _k (19) - F _act (19)| |F _k (20) - F _act (20)| 1 0 1 2 4 4 11 <== Minimum 2 1 0 0 7 8th 16 3 1 1 0 12 12 26

The control device is designed to determine the remaining cooking time of the food by comparing the determined current signal curve of the oxygen concentration with the plurality of oxygen reference signal curves, by comparing the determined current signal curve of the nitrogen concentration with the plurality of nitrogen reference signal curves and by comparing the determined current signal curve of the moisture concentration with the plurality of moisture reference signal curves.

Furthermore, the control device is designed to relate the signal values of the current signal curve and the stored reference signal curves to a predetermined reference value.

By relating the signal values to a predetermined reference value, incorrect evaluation due to an offset, i.e. a parallel offset of the curves, is reduced or prevented. For example, the remaining cooking time for one minute of cooking time is used as a reference value.

In a further embodiment, the control device is designed to determine the remaining cooking time of the food several times during the total cooking time of the food, in particular at predetermined time intervals. This allows the current remaining cooking time to be updated, calculated and displayed.

In a further embodiment, the control device is designed to start a timer initialized with the determined remaining cooking time at the time of determining the remaining cooking time and to automatically stop the cooking of the food after the initialized timer has elapsed.

This means that cooking ends at the right time without the user having to take any action. This ensures that the food is cooked to perfection.

In a further embodiment, the cooking appliance has a communication interface which is designed to receive updated reference signal profiles from a server via a network. Accordingly, the communication interface can also be designed to transmit the reference signal profiles stored in the memory to the server via the network.

By providing the communication interface, the cooking appliance is online-capable and can both load updated reference signal waveforms and provide updated reference signal waveforms for other cooking appliances via the network and the server.

In a further embodiment, the cooking appliance comprises a probe for determining the permittivity of the food in the cooking chamber. The control device can then be set up to additionally calculate the remaining cooking time of the food depending on the determined permittivity of the food.

The probe is inserted into the food being cooked. The inserted probe measures the frequency-dependent permittivity (dielectric constant) of the food being cooked using direct and alternating electrical fields. The measured data is compared with data stored in the control device in a similar way to spectrometry. By heating the food being cooked during the measurement, the measurement results can be made even clearer.

The cooking appliance is, for example, an oven, a microwave, a steamer or a warming drawer.

Furthermore, a method for operating a cooking appliance with a cooking chamber for cooking food is proposed. In a first step, a plurality of oxygen reference signal curves for an oxygen concentration in the cooking chamber, a plurality of nitrogen reference signal curves for a nitrogen concentration in the cooking chamber and a plurality of moisture reference signal curves for a moisture concentration in the cooking chamber are stored. In a second step, a current signal curve of the oxygen concentration in the cooking chamber, a current signal curve of the nitrogen concentration in the cooking chamber and a current signal curve of the moisture concentration in the cooking chamber are determined. A heating curve of the cooking chamber is recorded. In a further step, a remaining cooking time of the food is determined by comparing the determined current signal curves with the plurality of stored reference signal curves and depending on the recorded heating curve. The waveforms of the oxygen concentration, nitrogen concentration and moisture concentration in the cooking chamber determined during cooking performed by a user are recorded and the recorded waveforms are stored in the memory as reference waveforms.

Not according to the invention, a computer program product is described here which causes at least one step of a method for operating a cooking appliance as explained above to be carried out on a program-controlled device.

A computer program product such as a computer program means can be provided or delivered, for example, as a storage medium such as a memory card, USB stick, CD-ROM, DVD or in the form of a downloadable file from a server in a network. This can be done, for example, in a wireless communications network by transmitting a corresponding file with the computer program product or the computer program means.

Further advantageous embodiments and aspects of the invention are the subject of the dependent claims and the embodiments of the invention described below. The invention is explained in more detail below using preferred embodiments with reference to the attached figures.

Fig. 1

eine schematische Ansicht eines ersten nicht erfindungsgemäßen Beispiels eines Gargeräts

Fig. 2

eine schematische Ansicht eines weiteren nicht erfindungsgemäßen Beispiels eines Gargeräts

Fig. 3

eine schematische Ansicht eines erfindungsgemäßen Ausführungsbeispiels eines Gargeräts

Fig. 4

eine schematische Ansicht eines Ausführungsbeispiels eines Gargeräts;

Fig. 5

ein schematisches Ablaufdiagramm eines erfindungsgemäßen Ausführungsbeispiels eines Verfahrens zum Betreiben eines Gargeräts;

Fig. 6

ein Beispiel mit vier Signalverläufen von vier Datensätzen; und

Fig. 7

das Beispiel der Fig. 6 mit einem aktuellen Signalverlauf.

They show:

Fig.1

a schematic view of a first example of a cooking appliance not according to the invention

Fig.2

a schematic view of another example of a cooking appliance not according to the invention

Fig.3

a schematic view of an embodiment of a cooking appliance according to the invention

Fig.4

a schematic view of an embodiment of a cooking appliance;

Fig.5

a schematic flow diagram of an embodiment of a method for operating a cooking appliance according to the invention;

Fig.6

an example with four signal curves from four data sets; and

Fig.7

the example of Fig.6 with a current signal curve.

In the figures, identical or functionally equivalent elements have been given the same reference numerals unless otherwise stated.

In Fig.1 a schematic view of an example of a cooking appliance 1 is shown. The cooking appliance 1 has a cooking chamber 2 for cooking food (not shown). For example, the cooking appliance 1 is designed as an oven. In this example, the cooking chamber 2 can then be referred to as an oven.

A sensor 3 is arranged in the cooking chamber 2, which determines a current signal curve AS of a gas concentration in the cooking chamber 2. For example, the sensor 3 is set up to determine an oxygen concentration in the cooking chamber 2, a nitrogen concentration in the cooking chamber 2 or a moisture concentration in the cooking chamber 2.

Furthermore, the cooking appliance 1 has a memory 4 for storing a plurality of reference signal profiles R1-R3 for the gas concentration in the cooking chamber 2. The memory is, for example, a read-only memory. In particular, the memory 4 comprises a database for storing a plurality N of reference signal profiles. The database stores a data set for each of the N reference signal profiles R1-R3. The respective data set comprises a temporal sequence of reference signal values R1, R2 or R3 of the gas concentration in the cooking chamber 2 and an associated total cooking time for the food to be cooked in the cooking chamber 2. Without restricting generality, the memory device 4 of the cooking appliance 1 stores three reference signal profiles R1-R3. The number of stored reference signal profiles R1-R3 in the memory 4 can also be several hundred or thousands.

Furthermore, the cooking appliance 1 has a control device 5. The control device 5 is designed to control the cooking appliance 1 and in particular to carry out a plurality of predetermined cooking programs for cooking the food. The control device 5 is designed, for example, as an embedded system or as a microcontroller.

The control device 5 is further configured to determine a remaining cooking time RG of the food by comparing the determined current signal profile AS with the majority of stored reference signal profiles R1-R3. A specific total cooking time is assigned to the respective reference signal R1-R3 of the majority of reference signal profiles R1-R3 stored in the memory 4. The control device 5 then selects the reference signal profile R1-R3 by means of the comparison. which has a minimum distance to the determined current signal profile AS. The remaining cooking time RG is then determined by the control device 5 as the difference between the total cooking time assigned to the selected reference signal profile R1-R3 and a start time of cooking. The start time of cooking is detected by the control device 5 using signals.

In particular, the control device 5 is configured to calculate an average absolute deviation between the determined current signal curve AS and each of the stored reference signal curves R1-R3 and to select the reference signal curve R1-R3 with the calculated minimum average absolute deviation for determining the remaining cooking time RG.

Furthermore, the cooking appliance 1 has a display device 6 which is coupled to the control device 5 and is designed to display the determined remaining cooking time RG to a user.

The control device 4 is also designed in particular to record the signal curve of the gas concentration in the cooking chamber 2 determined by the sensor 3 during cooking carried out by a user and to store it in the memory 4 as a reference signal curve R1-R3.

Furthermore, the control device 5 is designed, for example, to relate the signal values of the current signal curve AS and the stored reference signal curves R1-R3 to a predetermined reference value. This advantageously makes it possible to avoid an offset of the individual signal values.

The control device 5 determines the remaining cooking time RG of the food during the total cooking time of the food, preferably several times, in particular at predetermined time intervals. The predetermined time intervals can be a few seconds or a few minutes.

Furthermore, the control device 5 can also be set up to start a timer initialized with the remaining cooking time RG at the time of determining the remaining cooking time RG and to automatically and automatically end the cooking of the food after the initialized timer has elapsed.

Fig.2 shows another example of a cooking appliance 1. The example of Fig.2 is based on the example of Fig.1 and differs only in that the example of Fig. 2 comprises three different sensors 8, 9 and 10. The cooking appliance 1 of the Fig. 2 For this purpose, it comprises an oxygen sensor 8 for determining a current signal curve AO of the oxygen concentration in the cooking chamber 2, a nitrogen sensor 9 for determining a current signal curve AN of the nitrogen concentration in the cooking chamber 2 and a humidity sensor 10 for determining a current signal curve AF of the humidity concentration in the cooking chamber. The memory 4 of the Fig.2 a plurality of oxygen reference signal waveforms R1, a plurality of nitrogen reference signal waveforms R2 and a plurality of humidity reference signal waveforms R3. The control device 5 of the Fig.2 is designed to determine the remaining cooking time RG of the food by comparing the determined current signal curve OA of the oxygen concentration with the plurality of oxygen reference signal curves R1, by comparing the determined current signal curve AN of the nitrogen concentration with the plurality of nitrogen reference signal curves R2 and by comparing the determined current signal curve AF of the moisture concentration with the plurality of moisture reference signal curves R3.

In Fig.3 The embodiment of a cooking appliance 1 according to the invention is shown. The embodiment of the Fig.3 is based on the example of Fig.2 and has all the characteristics of the example of Fig.2 In addition, the cooking appliance 1 of the Fig.3 a temperature sensor 7 arranged in the cooking chamber 2 for recording a heating curve AT of the cooking chamber 2. The control device 5 of the Fig.3 is then set up to calculate the remaining cooking time RG using the Fig.2 described comparisons and depending on the heating curve AT.

Fig.4 shows another embodiment of a cooking appliance 1. The embodiment of the Fig.4 is based on the first example of Fig.1 , but can also be based on the example of Fig.2 or the embodiment of the Fig.3 The cooking appliance 1 of the Fig.4 has a communication interface 11. The communication interface 11 is designed to receive updated reference signal waveforms R1-R3 via a network 12 from a server 13 and to update the reference signal waveforms stored in the memory 4 R1-R3 to the server 13 via the network 12. The communication interface 11 comprises, for example, an Ethernet interface. The network 12 is, for example, the Internet or a local area network (LAN).

In Fig.5 is a schematic flow diagram of an embodiment of a method for operating a cooking appliance 1 (see Fig.1 ). The cooking appliance 1 has a cooking chamber 2 for cooking food and a control device 3 for carrying out a plurality of predetermined cooking programs P1-P3.

In step 501, a plurality of reference signal waveforms R1-R3 for a gas concentration in the cooking chamber 2 are stored.

In step 502, a current signal curve AS of the gas concentration in the cooking chamber 2 is determined.

In step 503, a remaining cooking time RG of the food to be cooked is determined by comparing the determined current signal waveform AS with the majority of the stored reference signal waveforms R1-R3.

Fig.6 shows an example with four signal curves 601, 602, 603, 604 from four data sets and thus with four signal curves. The signal curves 601, 602, 603, 604 are stored there at discrete times between 5 and 20 minutes.

In Fig.7 is the example of Fig.6 with a current signal curve 701. The current signal curve 701 has the smallest deviation from the curve 602 in this example. Consequently, the baking time assigned to the curve 602 is decisive for the remaining cooking time.

List of reference symbols

1

Cooking appliance

2

Cooking chamber

3

sensor

4

Storage

5

Control device

6

Display device

7

Temperature sensor

8th

Oxygen sensor

9

Nitrogen sensor

10

Humidity sensor

11

Communication interface

12

network

13

server

501-503

Process step

AS

current signal curve

A0

current signal curve of the oxygen concentration

AT

current signal curve of the nitrogen concentration

AF

current signal curve of the moisture concentration

AT

current heating curve

R1-R3

Reference signal curve

RG

Remaining cooking time

Claims (11)

1. Cooking appliance (1) having

   a cooking compartment (2) for cooking food to be cooked,

   an oxygen sensor (8), arranged in the cooking compartment (2), for determining a current signal curve (AO) of an oxygen concentration in the cooking compartment (2),

   a nitrogen sensor (9), arranged in the cooking compartment (2), for determining a current signal curve (AN) of a nitrogen concentration in the cooking compartment (2),

   a humidity sensor (10), arranged in the cooking compartment (2), for determining a current signal curve (AF) of a humidity concentration in the cooking compartment (2),

   a temperature sensor (7), arranged in the cooking compartment (2), for receiving a heating curve (AT) of the cooking compartment (2),

   a storage unit (4), in which a plurality of oxygen reference signal curves (R1) for the oxygen concentration in the cooking compartment (2), a plurality of nitrogen reference signal curves (R2) for the nitrogen concentration in the cooking compartment (2) and a plurality of humidity reference signal curves (R3) for the humidity concentration in the cooking compartment (2) are stored, and

   a control facility (5) which is designed to determine a residual cooking time (RG) of the food to be cooked by means of a comparison of the determined current signal curves (AO, AN, AF) with the plurality of stored reference signal curves (R1- R3) and as a function of the recorded heating curve (AT), and

   wherein the control facility (5) is designed to record the signal curves (AO, AN, AF), determined by the sensors (8, 9, 10) during a cooking process carried out by a user, of the oxygen concentration, nitrogen concentration and humidity concentration in the cooking compartment (2) and to store the recorded signal curves as reference signal curves (R1-R3) in the storage unit (4).
2. Cooking appliance according to claim 1, characterised by a display facility (6) which is designed to indicate the determined residual cooking time (RG) to a user.
3. Cooking appliance according to claim 1 or 2, characterised in that a determined overall cooking time is assigned to the respective reference signal curve (R1-R3) of the plurality of reference signal curves (R1-R3), wherein the control facility (5) is designed to select the reference signal curve (R1-R3) with a minimal distance from the determined current signal curve (AS) by means of the comparison and to determine the residual cooking time (RG) as a difference between the overall cooking time assigned to the selected reference signal curve (R1-R3) and a start time of the cooking process.
4. Cooking appliance according to claim 3, characterised in that the control facility (5) is designed to calculate an average absolute variation between the determined current signal curve (AS) and each of the stored reference signal curves (R1-R3) and to select the reference signal curve (R1-R3) with the calculated minimal average absolute variation for the determination of the residual cooking time (RG).
5. Cooking appliance according to one of claims 1 to 4, characterised in that the storage unit (4) comprises a database for storing N reference signal curves (R1-R3), wherein the database stores a dataset for each of the N reference signal curves (R1-R3), wherein the respective dataset comprises a temporal sequence of reference signal values (R1-R3) of the gas concentration in the cooking compartment (2) and an assigned overall cooking time for the food to be cooked in the cooking compartment (2).
6. Cooking appliance according to claim 1, characterised in that the control facility (5) is designed to determine the residual cooking time (RG) of the food to be cooked by means of a comparison of the determined current signal curve (A0) of the oxygen concentration with the plurality of oxygen reference signal curves (R1), by means of a comparison of the determined current signal curve (AN) of the nitrogen concentration with the plurality of nitrogen reference signal curves (R2) and/or by means of a comparison of the determined current signal curve (AF) of the humidity concentration with the plurality of humidity reference signal curves (R3).
7. Cooking appliance according to one of claims 1 to 6, characterised in that the control facility (5) is designed to refer the signal values of the current signal curve (AS) and the stored reference signal curves (R1-R3) to a predetermined reference value.
8. Cooking appliance according to one of claims 1 to 7, characterised in that the control facility (5) is designed to repeatedly determine the residual cooking time (RG) of the food to be cooked during the overall cooking time of the food to be cooked, in particular at predetermined time intervals.
9. Cooking appliance according to one of claims 1 to 8, characterised in that the control facility (5) is designed to start a timer initialised with the determined residual cooking time (RG) at the time instant of determining the residual cooking time and to automatically end the cooking of the food to be cooked after the initialised timer has elapsed.
10. Cooking appliance according to one of claims 1 to 9, characterised by a communication interface (11) which is designed to receive updated reference signal curves (R1-R3) by way of a network (12) from a server (13) and/or to transmit the reference signal curves (R1-R3) stored in the storage unit (4) to the server (13) by way of the network (12).
11. Method for operating a cooking appliance (1) according to claim 1,
    having the steps:

    storing (501) a plurality of oxygen reference signal curves (R1) for an oxygen concentration in the cooking compartment (2), a plurality of nitrogen reference signal curves (R2) for a nitrogen concentration in the cooking compartment (2) and a plurality of humidity reference signal curves (R3) for a humidity concentration in the cooking compartment (2),

    determining (502) a current signal curve (AO) of the oxygen concentration in the cooking compartment (2), a current signal curve (AN) of the nitrogen concentration in the cooking compartment (2), a current signal curve (AF) of the humidity concentration in the cooking compartment (2),

    recording a heating curve (AT) of the cooking compartment (2),

    determining (503) a residual cooking time (RG) of the food to be cooked by means of a comparison of the determined current signal curves (AO, AN, AF) with the plurality of stored reference signal curves (R1-R3) and as a function of the recorded heating curve (AT), and

    recording the signal curves (AO, AN, AF), determined during a cooking process carried out by a user, of the oxygen concentration, nitrogen concentration and humidity concentration in the cooking compartment (2) and storing the recorded signal curves as reference signal curves (R1-R3) in the storage unit (4).

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