Field of the invention

[0001] The present invention relates to an induction cooking system configured for autonomous long-term cooking of food items, a method of controlling the long-term cooking process and the use of an induction cooking system for preparing food items according to a long-term cooking template.

Background of the invention

[0002] Preparation of food items such as steaks is a manual process of which the result tends to vary from one preparation process to the next. The reasons for the diversity in the results of preparing e.g. steaks are many and may include power control, type of steak, thickness of steak, etc.

[0003] When the food preparation process is a long-term food preparation process prior art document EP1703775 describes to control the power provided to the cookware. More specific to use less than 5% of max power in a time interval such as the food preparation process. However, only using 5% of maximum power gives no guaranties for uniform cooking results of subsequent cooking processes of the same type of food item.

[0004] Prior art document US10595366 describes an induction hob comprising a controller and a cooking point comprising at least one induction heating coil. A relationship between a cooking vessel temperature and a heating power of the induction heating coil as area power or power density per unit area is advantageously stored in the controller which sets or provides the desired specific cooking vessel temperature in the steady state or stable state or during long-term operation. However, the mere maintenance of a constant temperature does not in itself guarantee a uniform cooking results of subsequent cooking processes of the same type of food item. Summary of the invention

[0005] The inventors have identified the above-mentioned problems and challenges related to obtaining uniformed cooking results of subsequent cooking processes, and subsequently made the below-described invention which among other things suggest an automated cooking process that increase the chances for obtaining a uniform cooking result of subsequent cooking processes of the same type of food item.

[0006] In an aspect, the invention relates to an induction cooking system comprising: an induction hob; an induction cookware comprising: a base part for placing on an induction hob; a temperature sensor arranged in said base part; a power supply; and a transmitter; a memory comprising a long-term cooking template, said long-term cooking template defining at least a first heating period having a first time duration and a second heating period having a second time duration, wherein said first time duration and said second time duration are different, wherein said long-term cooking template is automatically executable by said induction cooking system, and wherein said execution involves an automatic transition from said first heating period to said second heating period.

[0007] Thereby is provided an advantageous induction cooking system capable of automatic handling of a long-term cooking template. As the automatic execution includes an automatic transition between the first heating period and the second heating period it is ensured that the entire cooking process defined by the long-term cooking template can be carried out with no input by a user of the cooking system during the cooking process. In this way the user can simply focus on placing ingredients to be cooked in the induction cookware and have the cooking system execute the entire cooking process subsequently while the user is free to perform other tasks.

[0008] As the long-term cooking template is facilitated by an induction cooking system including an induction cookware and an induction hob there is also provided the advantage of added flexibility compared to typical slow cookers that are standalone devices. Such stand-alone devices are not operable by an induction hob and therefore has to be placed elsewhere than the hob and thereby take up valuable space on the kitchen counter. Furthermore, such stand-alone devices are typically limited to low power (and thereby low cooking temperatures) due to reasons of safety concerns. However, implementing the long-term cooking template in an induction cooking system ensures that the available power is not technically limited by such safety concerns, and usability of the long-term cooking process is greatly improved as more cooking processes become possible to perform.

[0009] By implementing the long-term cooking template in an induction cooking system is also achieved the advantage that the cooking process can be performed at various positions on the induction hob and as an induction cooking system typically comprises a plurality of differently sized induction cookware the user can select the most appropriate induction cookware for the cooking process at hand.

[0010] In the context of the present invention an “induction cooking system” is understood as a system comprising any number of induction hobs and induction cookware capable of being communicatively coupled between the induction hob(s) and the induction cookware(s). For example an induction cooking system according to the present invention may according to one embodiment of the invention comprise a single induction hob and a single induction cookware, however, in other embodiments of the invention the induction cooking system may comprise any number of induction hobs and any number of induction cookware, for example one induction hob and a plurality of pieces of induction cookware such as two pieces of induction cookware, two induction hobs and a single piece of induction cookware, and two induction hobs and a plurality of pieces of induction cookware, such as two pieces of induction cookware, for example 4 pieces of induction cookware.

[0011] In the context of the present invention, the term “cookware” is understood as any kind of cooking receptacle or cooking vessel in (or on) which food is placed when being cooked. The term cookware may thus encompass any type of cooking receptacle or cooking vessel including cooking pots such as sauce pots, stock pots and stew pots and cooking pans such as saucepans, saucier pans, saute pans, frying pans, grill pans and wok pans. Furthermore, within the context of the present invention, the term “cookware” is understood as a kind of cooking receptacle or cooking vessel arranged to be placed on a hob for the purpose of cooking food.

[0012] By the term hob may also be understood a cooktop or a stove. A hob may provide heating to cookware placed thereon through different heating mechanisms depending on the type of the hob. A gas hob delivers heating energy through burning of a gas, a ceramic hob delivers heating through heat radiation, and an induction hob delivers heating through induction. Of these types of hobs an induction hob is typically the most precise, reactive, and energy efficient, and for these reasons induction hobs are gaining grounds among consumers of household products but also in professional kitchens.

[0013] Thus, the term “induction cookware” is understood as any kind of cooking receptacle, or cooking vessel as indicated above which is at least capable of being heated through induction on an induction hob.

[0014] The present induction cookware comprises a base part which is suitable for placing on an induction hob. That is, the base part of the induction cookware is the part of the cookware that is in contact with the induction hob during cooking. The base part of the cookware may comprise one or more material layers configured to being inductively heated by an induction hob. For example, the one or more material layers may comprise a ferromagnetic material layer.

[0015] The present induction cookware comprises a temperature sensor arranged in the base part of the cookware. By the term “temperature sensor” is understood any kind of sensor which is capable of establishing a measure that is representative of a temperature of the base part of the cookware. The measure may be a direct measure of temperature, or it may be a measure from which a temperature is derivable or deducible from. Examples of temperature sensors include resistive temperature detectors (RTD), thermocouples and thermistors.

[0016] The temperature sensor is advantageously arranged in the base part of the cookware. Thereby is ensured a stable arrangement of the sensor protecting the sensor from dislodging due to use of the cookware or impacts to the cookware from e.g. dropping of the cookware. Furthermore, arranging the temperature sensor in the base part of the cookware is advantageous in that the base part of the cookware is in close proximity to a cooking surface of the cookware (surface which is in contact with food present in the cookware). Thereby is ensured that an established measure of temperature may be more representative of actual temperatures of food items present on the cooking surface than if the temperature sensor were arranged in (or on) the cookware at a position further away from the food items present in the cookware.

[0017] Accordingly, when referring to a target temperature in this document (unless otherwise stated), it is the desired temperature of the food present in the cookware such as the desired core temperature of a steak, an average temperature of a liquid / mash, etc. One food preparation process may have more than one target temperature during the preparation process.

[0018] When referring to a “cooking temperature” a reference is made to a temperature related to cooking of food item(s) present in the induction cookware, such as a temperature of a cooking surface of the induction cookware.

[0019] The actual temperature is the temperature of the food being prepared. During a food heating period, the actual temperature increases towards the target temperature. Then, when the actual and the target temperatures are substantially the same, the actual temperature is maintained as close to the target temperature as possible by controlling the inductive power in response to temperature sensor readings. It is noted that the actual temperature is estimated e.g. based on a compensation model taking into account the particular type of food and cookware.

[0020] In the context of the present invention, the term “power supply” is understood as any device capable of storing energy and delivering electric power or harvesting energy and delivering electric power. As an example, the power supply may comprise a battery, such as a replaceable battery or a rechargeable battery, an energy harvesting unit capable of harvesting thermal energy or harvesting energy through induction, or a mains connection. Providing a power source in the induction cookware is advantageous in that the induction cookware may then comprise electronic components including among others a transmitter.

[0021] In the context of the present invention, a “transmitter” is understood as any kind of unit capable of wireless data transmission. The transmitter may facilitate data transmission according to various wireless communication protocols including Bluetooth, such as Bluetooth low energy (BLE), WiFi, cellular communication protocols including 3G, 4G, LTE and 5G, and other wireless communication protocols such as Zigbee and Z-Wave.

[0022] In the context of the present invention, a “long-term cooking template” is understood as a cooking process defined by a sequence of multiple heating periods including at least a first heating period and a second heating period, the second heating period having a longer time duration than the first heating period. The long-term cooking process may include additional heating periods including at least a third heating period. The long-term cooking process according to the present invention facilitates among others execution of cooking processes commonly referred to as “slow cooking”. Such cooking processes are characterized by low cooking temperatures and long cooking times, compared to e.g., temperatures and cooking times involved in conventional cooking or grilling of a steak.

[0023] In the context of the present invention, a “heating period” is understood as a time period in which food items and/or liquids present in an induction cookware are at elevated temperatures with respect to the surroundings of the induction cooking system. For example, the first and second heating period may define a time period in which inductive heating is applied to the induction cookware by the induction hob. Unless the first heating period includes both a food heating period and a food temperature maintaining period, the provided inductive power in the first and second heating periods would typically be different.

[0024] When referring to food in this document, food should be understood as any kind of food or part of a meal / dish that can be prepared on / in a cookware. This includes food with different texture, appearance (visual and physical), including but not limited to e.g. soup, steak, damping vegetables, boiling eggs, sauce, etc. Hence when referring to cooking or preparation of food, a reference is made to the process of heating the food.

[0025] According to an explanatory embodiment of the invention, said induction cooking system comprises a controller arranged to automatically execute at least a part of said long-term cooking template.

[0026] The induction cooking system may comprise a controller, such as a data processing arrangement, which is arranged to perform automatic execution of at least a part of the long-term cooking template, for example the entire long-term cooking template including transitions between heating periods, such as the transition between the first heating period and the second heating period.

[0027] According to an explanatory embodiment of the invention, said controller is arranged in said induction cookware.

[0028] The controller may be arranged in the induction cookware, such as in a handle of the induction cookware.

[0029] According to an explanatory embodiment of the invention, said memory is a digital memory arranged in said induction cookware, said induction hob or in an external device.

[0030] The memory may be any kind of digital memory from which a data processor controlling the preparation of food, including the inductive power, may have access to. Based on the access to the memory, the data processor may have access to temperature settings, time duration of heating periods, etc. specified by the long-term cooking template. The external device may include a tablet, smart phone, cloud service, etc.

[0031] According to an explanatory embodiment of the invention, said induction hob is arranged to provide inductive power to said induction cookware in at least said first heating period and said second heating period. [0032] As the induction cooking system executes the long-term cooking template, inductive power may be provided to the induction cookware in the first and second heating period as prescribed by the long-term cooking template.

[0033] According to an explanatory embodiment of the invention, said second time duration is greater than said first time duration.

[0034] When said first heating period is a so-called food heating period during which the temperature curve measured by the temperature sensor increases compared to the second heating period when the second heating period is a so-called temperature maintaining period during which the temperature curve is steady or oscillating around a target temperature. The target temperature may vary according to the long-term cooking template.

[0035] According to an explanatory embodiment of the invention, said first time duration and said second time duration are defined by inductive power provided to said induction cookware and/or temperature measurements provided by said temperature sensor.

[0036] The transition from the first period to the second period may be determined e.g. by a change in provided inductive power either an increase or a decrease in power above or below a predefined threshold power. Alternatively, response from the temperature sensor compared with a desired temperature may be used to define the first and second heating periods.

[0037] According to an explanatory embodiment of the invention, said time durations continue after said inductive power is reduced.

[0038] To reduce energy consumption, residual heat, mainly from the base part of the cookware may be used to heat the food. Hence, a period in which food is heated, may continue after the induction power is reduced.

[0039] According to an explanatory embodiment of the invention, said first time duration and said second time duration is defined by said long-term cooking template. [0040] The long-term cooking template may specify predetermined inductive power levels to be applied for predetermined time durations of the first and second heating periods. A controller may, based on readings from the temperature sensor, adapt (increase or decrease time or inductive power) these time durations / inductive power levels to better reach a target temperature.

[0041] According to an explanatory embodiment of the invention, said first time duration and said second time duration are defined by a comparison of a target temperature and an actual temperature.

[0042] Hence, a change between a first and a second heating period may be said to happen when the target and actual temperatures are substantially the same. Typically, this will imply that the inductive power is reduced at a point in time prior to when the two temperatures meet.

[0043] The actual temperature (of the food being prepared) is typically measured indirectly by the temperature sensor of the base part of the cookware. By tests or models of a particular type of food, the temperature measurements from the temperature sensor can be translated to a temperature of the food prepared in the test or model. Hence, the transition from one heating period to the other may happen when the temperature received by the controller from the temperature sensor reaches a threshold temperature which typically would be higher than the target temperature of the food.

[0044] According to an explanatory embodiment of the invention, said induction hob is arranged to provide an inductive power to said induction cookware during said second heating period, and wherein said inductive power is determined by said longterm cooking template to maintain a cooking temperature throughout said second heating period.

[0045] According to an explanatory embodiment of the invention, said first heating period is a food heating period in which said inductive power is increased and / or wherein said first heating period is a food temperature maintaining period in which said inductive power provided to said cookware is substantially the same. [0046] Depending on the long-term cooking template, the purpose of the first heating period may be to heat food to bring up a temperature of the food to a target temperature. In this case, the first heating period may be referred to as a food heating period. According to the long-term cooking template, during the food heating period, the food may be heated to obtain a desired texture, outer surface, or temperature for further preparation, etc. This means that the inductive power provided to the cookware containing the food may be provided with a long-term cooking template defined increase. The long-term cooking template may define an increase of inductive power in steps from e.g., 0W to e.g., 1800W or from e.g., 0W to e.g., 200W and subsequently to e.g., 2300W. Alternatively, the long-term cooking template may define a high start power and subsequently a decrease of inductive power in one or more steps to maintain a desired temperature.

[0047] In addition, the purpose of the first heating period may be to maintain a longterm cooking template defined temperature of the cookware and thereby of the food contained therein. Hence, the first heating period may both establish a target temperature of the food and maintain that temperature of the food for a period of time specified by the long-term cooking template.

[0048] It should be mentioned that during the food temperature maintain period i.e., during the period the actual temperature is maintained substantially equal to the target temperature, the long-term cooking template may specify variations of the target temperature of the food leading to a variation of the inductive power provided to the cookware.

[0049] Accordingly, the long-term cooking template may either provide a relatively short heating period in the beginning of the cooking process with a high-power level to quickly heat up the food item. Alternatively, a relatively short heating period with high power is provided at the end of the cooking process to finish the food item.

[0050] According to an explanatory embodiment of the invention, said second heating period is a food temperature maintaining period in which said inductive power provided to said cookware is substantially the same and / or wherein said second heating period is a food finishing period in which more inductive power is provided to said cookware that at any time during said first period.

[0051 ] Depending on the long-term cooking template, the second food heating period may be referred to as the food temperature maintaining period. In this case, the inductive power may be controlled as described above so as to either maintain an actual temperature of the food or adjust and maintain an actual temperature of the food.

[0052] According to an explanatory embodiment of the invention, said first heating period is a food heating period, and wherein said second heating period is a food temperature maintaining period.

[0053] According to an explanatory embodiment of the invention, a maximum inductive power provided to said induction cookware by said induction hob during said first heating period is greater than a maximum inductive power provided to said induction cookware by said induction hob during said second heating period.

[0054] According to an explanatory embodiment of the invention, inductive power provided to said induction cookware by said induction hob during said second heating period is limited to 250 watts, such as limited to 200 watts, such as limited to 150 watts, such as limited to 120 watts.

[0055] The power supplied to the induction cookware may be limited to 250 watts, such as limited to 200 watts, such as limited to 150 watts 120 watts during the second heating period, thus inductive power supplied to the cookware may be in the range from 0 watts to 250 watts, such as in the range from 0 watts to 200 watts, such as in the range from 0 watts to 150 watts, such as in the range from 0 watts to 120 watts, during the second heating period, for example 100 watts. Preferably, the power is limited to 120 watts during the second heating period when a power limit is used. Such a power limit is particular advantageous for executing a sous vide recipe. Limiting the inductive power supplied to the induction cookware in the second heating period, such as limiting the inductive power to 120 watts, is advantageous in that the temperature of the cookware is kept at a temperature sufficiently low to avoid that a fire may be started due to the cooking process. Thereby may be achieved an automatic execution of a long-term cooking template where the safety of the execution is improved.

[0056] According to an explanatory embodiment of the invention, said long-term cooking template defines at least two different induction power levels during said food heating period.

[0057] Having a stepwise increase (two or more steps) of the induction power during the food heating period is advantageous in that for some types of food such as a steak an instant increase of inductive power (and thereby heat to a steak which may be taken directly from a fridge) from e.g. 0-2000W may damage the texture of the steak and thereby the dining experience.

[0058] According to an explanatory embodiment of the invention, said long-term cooking template defines at least 3, preferably at least 4 preferably at least 5 different induction power levels during said temperature maintaining period.

[0059] By providing different levels of inductive power, the temperature of the base of the cookware is substantially constant during said food temperature maintaining period. A constant or substantially constant temperature is advantageous in that the food is prepared according to the long-term cooking template i.e., to obtain a desired texture, colour, juiciness, flavour, taste, etc. of the food.

[0060] By substantially constant temperature should be understood a temperature that may vary within a few degrees such as within 0-5 degrees such as preferably plus minus 1 degree.

[0061 ] The different levels of inductive power may be referred to as one or a plurality of individual periods that together is referred to as the temperature maintaining period.

[0062] According to an explanatory embodiment of the invention, said food temperature maintaining period is longer than 1 hour, preferably more than 2 hours, most preferably more than 3 hours. [0063] The duration of the temperature maintaining period is determined by the longterm cooking template and depends on the type of food and how the food is to be prepared according to long-term cooking template. In one specific embodiment an egg is soft-boiled by a long-term cooking template which does not require a by passe of the auto-shut-off In an embodiment a sous vide recipe may be prepared according to a long-term cooking template over a duration of 20 minutes to several hours such as e.g. up to 100 hours.

[0064] As an example of a long-term cooking template, an egg may be prepared e.g. at 71 °C for e.g. 60 minutes. Another example is a steak prepared in 20 minutes. Accordingly, the term long-term cooking may be relative with respect to the food being prepared i.e. 20 minutes is long time for preparing a steak but not for boiling potatoes.

[0065] According to an explanatory embodiment of the invention, said temperature maintaining period is characterized by cooking temperatures of said induction cookware being less than 100 degrees Celsius.

[0066] The cooking temperatures used in the food temperature maintain period may be above room temperature (e.g., above 20 degrees Celsius) and less than 100 degrees Celsius, such as below 80 degrees Celsius, such as below 70 degrees Celsius, for example less than 60 degrees Celsius. The temperature is determined by the recipe of the long-term cooking template and thus may of course also be above 100 degrees Celsius such as between 100 and 200 degrees Celsius.

[0067] According to an explanatory embodiment of the invention, said long-term cooking template comprises a third heating period, wherein said third heating period is a food finishing period in which more inductive power is provided to said cookware that at any time during said second heating period or wherein said third heating period is a reduced heating period in which less inductive power is applied to said cookware than at any time during said second heating period.

[0068] The third heating period is a final heating period for the cooking process at which less inductive power, or no inductive power, is applied to the induction cookware. The third heating period may be usable for storing the cooked food product at an elevated temperature after cooking. This is advantageous in that the food product can be kept at a desirable temperature even after being cooked thereby ensuring that the food is safe to eat or having a desired texture whenever desired.

[0069] According to an explanatory embodiment of the invention, said long-term cooking template comprises a third heating period in which no inductive power is applied to said cookware.

[0070] No inductive power may be applied to the induction cookware during the third heating period. In other words, there is only residual heat in the induction cookware, and the temperature of the induction cookware (and food items therein) will decrease over time. Having such a third heating period in a long-term cooking template is advantageous in that energy consumption of cooking may be reduced. For some recipes, such as rice porridge and other recipes require cooking

[0071] It should be mentioned that a cooking recipe may comprise several heating periods such as between 1 and 10 heating periods.

[0072] According to an explanatory embodiment of the invention, said first heating period and/or said second heating period is partly determined on the basis of said third heating period.

[0073] Determining the first and/or second heating period on the basis of the third heating period is advantageous in that residual heat present in the induction cookware resulting from the heating provided in the second heating period can be taken into account in the cooking process and thereby lead to a more energy efficient cooking process.

[0074] According to an explanatory embodiment of the invention, said execution involves an automatic transition from said second heating period to said third heating period.

[0075] According to an explanatory embodiment of the invention, the energy used for heating during a period of time of said food heating period is higher than the energy used for heating during an equally long period of time of said temperature maintaining period.

[0076] Energy should be understood as the integral of power over time (dp/dt, where p is Power and t is time). Accordingly, more energy is used during a period of time of e.g. 10 seconds of the food heating period than during a period of time of 10 seconds of the temperature maintaining period.

[0077] According to an explanatory embodiment of the invention, the energy consumption during a time period of said food heating period is 2 times higher, preferably 3 times higher, most preferably 4 times higher than the energy consumption during an equally long period of time of said temperature maintaining period.

[0078] According to an explanatory embodiment of the invention, the energy consumption during said food heating period is 2 times higher, preferably 3 times higher, most preferably 4 times higher than the sum of energy consumed during said temperature maintaining period.

[0079] According to an explanatory embodiment of the invention, said long-term cooking template comprises a recipe defining a target temperature to be maintained during said temperature maintaining period

[0080] According to an explanatory embodiment of the invention, said target temperature is a temperature of one or more food items to be prepared.

[0081] According to an explanatory embodiment of the invention, said recipe is configured to receive food specific input.

[0082] Cooking according to a recipe of the long-term cooking template is advantageous in that the same (or substantially the same) result can be obtained at two subsequent cooking processes. This is especially true when a user updates the recipe with food specific input such as thickness of a steak, volume of a mash or soup, etc.

[0083] The target temperature of food such as a steak is established prior to the cooking hereof e.g. based on a compensation model or test cookings of the particular type of meat having a particular thickness and provided with induction power via a cookware (which also sometimes are of a particular type). The target temperature of food of a recipe of the long-term cooking template is thus decided based on the model / test cookings.

[0084] According to an explanatory embodiment of the invention, said controller is arranged to calculate an inductive power to be provided to said induction cookware by said induction hob to obtain a target temperature in said induction cookware prescribed by said long-term cooking template, wherein said calculation is based on one or more temperature measurements provided by said temperature sensor.

[0085] According to an explanatory embodiment of the invention, said controller is configured for calculating at least the duration of said temperature maintaining period and the amount of inductive power needed during said temperature maintaining period based on information of start time and end time of a food preparation process described by a long-term cooking template to obtain a desired food preparation result.

[0086] In this way, the long-term cooking template is dynamic in that based on information of start time i.e. when the food preparation process start and a desired end time of the food preparation process, the temperature profile for the entire food preparation process may be determined. Hence, if the duration between start and end time is shorter the temperature in this period is higher and vice versa.

[0087] Alternatively, the long-term cooking template is able to provide information of the start time based on information of the end time of the food preparation process for a particular recipe.

[0088] According to an explanatory embodiment of the invention, said long-term cooking template is configured to activate a visual or audial alarm when said food needs attention according to said recipe.

[0089] Attention may include manual interactions such as turning a steak, stirring or the like. The alarm may include a flashing light emitting diode on the induction hob or cookware, a noise / voice, pictogram or animation on the display of a tablet or smartphone, smart wristwatch, separate display etc.

[0090] According to an explanatory embodiment of the invention, said long-term cooking template is configured to suggest one of a plurality of available induction cookware to a user.

[0091] If more than one cookware is associated or comprised by the induction cooking system, the long-term cooking template may suggest the most appropriate cookware for a particular long-term food preparation process.

[0092] According to an explanatory embodiment of the invention, said induction cooking system comprises a user interface, wherein said user interface is comprised by at least one item from the list comprising: tablet, smartphone, induction hob and cookware.

[0093] The induction cooking system is controllable from a user interface allowing a user to activate, control, change and monitor the food preparation process. A user interface in the form of an external device such as a portable device is advantageous in that it has the effect, that the food preparation process can be controlled and / or monitored from further away or even a more remote location. In addition, the interface may include an alternative display such as a display external to the cooking hob.

[0094] According to an explanatory embodiment of the invention, said long-term cooking template is configured for bypassing an auto turn-off function of said induction hob.

[0095] Some induction hobs comprise an automatic turn off function that after a predetermined time turn of the inductive power provided to the cookware. Hence, unless such automatic turn off function is bypassed, there is a risk that the preparation of food according to the long-term cooking template is terminated before the preparation of food is finish. Therefore, it is advantageous to bypass any such automatic turn off functions. This can be safely done without compromising safety by limiting the total allowable power to each cooking zone and cookware. [0096] According to an explanatory embodiment of the invention, said induction cooking system is configured to monitor temperature of said induction cookware throughout execution of said long-term cooking template.

[0097] The induction cooking system may be configured to monitor the temperature of the induction cookware during execution of the long-term cooking template. The monitoring of the temperature may be carried out using the temperature sensor of the induction cookware. Monitoring the temperature during execution of the long-term cooking template is advantageous in that the system may detect whether specific food items processed according to the long-term cooking template have been maintained at sufficiently high temperatures throughout the cooking process, and the system may alert a user using a visual or audial alarm if the food items are rendered unsafe. For example, when cooking food items over long a long period, it is important that the temperatures used are high enough to avoid formation of botulinum toxin.

[0098] According to an explanatory embodiment of the invention, said induction cooking system is controlled according to the method of any of the preceding paragraphs.

[0099] In an aspect the invention relates to a method of operating an induction cooking system comprising an induction hob and an induction cookware, said induction cookware comprising a base part for placing on said induction hob, a temperature sensor arranged in said base part, a power supply, and a transmitter; the method comprising the steps of: placing said induction cookware on said induction hob, and activating a long-term cooking template, said long-term cooking template defining a first heating period and a second heating period, the time duration of which are different, wherein said long-term cooking template is automatically executable by said induction cooking system, and wherein said execution involves an automatic transition from said first heating period to said second heating period.

[0100] According to an explanatory embodiment of the invention, said step of placing said induction cookware comprises placing one or more food items in said induction cookware. [0101] It should be noted that the food items to be prepared may be placed in / on the induction cookware when the induction cookware is placed on the induction hob or before the induction cookware is placed on the induction hob.

[0102] According to an explanatory embodiment of the invention, a temperature measured by said temperature sensor is compared to a threshold temperature specified in said long-term cooking template and wherein induction power provided to said induction cookware is controlled according to said comparison.

[0103] Hence, when a long-term cooking template is selected, the induction system knows the temperature development required to prepare the food item and the induction system then based on this information and input from the temperature sensor control the induction power to achieve this temperature development.

[0104] According to an explanatory embodiment of the invention, said threshold temperature is different from a target temperature of said one or more food items to be prepared.

[0105] The measured temperature is not the same as the temperature of the food items to be prepared because the temperature sensor is not positioned inside the food time to be prepared. The difference between the measured temperature and the actual temperature of the food item being prepared is determined prior to cooking e.g. by test cookings or food preparation models. The temperature difference is subtracted from the desired target temperature of the food items to establish the threshold temperature specified by the long-term cooking template. It should be noted that a cooking process may include a plurality of target temperatures to be reached one after the other during the cooking process.

[0106] According to an explanatory embodiment of the invention, said second heating period has a time duration that is greater than a time duration of said first heating period.

[0107] According to an explanatory embodiment of the invention, said long-term cooking template comprises a third heating period. [0108] According to an explanatory embodiment of the invention, said activation of said long-term cooking template is initiated by a user via a user interface comprised by said induction cooking system.

[0109] A user interface may be the display of a tablet or similar portable device. Such tablet may comprise an application that is able to communicate with other parts of the induction system via the transmitter. Alternatively, a user interface may be a display or button of the induction cookware and / or the induction hob or a separate display or other means.

[0110] According to an explanatory embodiment of the invention, activation of said long-term cooking template further includes selecting a cooking zone of said induction hob.

[0111] According to an explanatory embodiment of the invention, activation of said long-term cooking template further includes selecting one of a plurality of suitable induction cookware.

[0112] In induction systems having more than one suitable induction hobs and more than one suitable induction cookware, the activation of the long-term cooking process includes selecting an induction hob and / or cookware. Further, in the situation where the selected induction hob includes more than one cooking zone, the activation may also include specifying a cooking zone.

[0113] According to an explanatory embodiment of the invention, said induction cooking system prompts said user to select a long-term cooking template from a plurality of long-term cooking templates stored in a digital memory comprised by said induction cooking system.

[0114] According to an explanatory embodiment of the invention, said induction cooking system prompts said user to select an induction cookware from a plurality of induction cookware of said induction cooking system.

[0115] The user may specify induction hob, cookware and / or cooking zone in response to a suggestion presented to the user via the user interface from the induction cooking system. Hence, if more than one cookware is associated or comprised by the induction cooking system, the induction cooking system may suggest the most appropriate cookware for a particular food preparation process.

[0116] The induction cooking system may with respect to the digital memory also comprise external data storage communicating with other elements of the induction cooking system. A cloud service may be an example of an external data storage.

[0117] According to an explanatory embodiment of the invention, said long-term cooking template includes a recipe, and wherein said user updates said recipe with food specific information.

[0118] This is advantageous in that based on the thickness of a steak or volume of a soup, etc. provided by the user, the recipe adapts the target temperature(s) which has to be reached during the cooking process.

[0119] According to an explanatory embodiment of the invention, said user leaves the cookware unattended for at least one hour during a cooking process following said recipe of said long-term cooking template.

[0120] This is advantageous in that the food item is prepared as desired according to the recipe without the user needing to pay attention to the cooking process. The duration of the cooking process being unattended may be minutes such as 10 up to hours. The user may leave the cookware even though the cooking system / cooking hob heat up one zone for a period of time that is longer than the period of time after which the hob normally would turn off i.e., bypassing the auto shut off function of the induction hob.

[0121] According to an explanatory embodiment of the invention, said induction cooking system comprises a digital memory comprising a plurality of long-term cooking templates, wherein a controller, in response to input from said user interface, executes a user selected long term cooking template.

[0122] According to an explanatory embodiment of the invention, said automatic transition is made in response to a match between a temperature measured by said temperature sensor and a threshold temperature specified by said long-term cooking template

[0123] The measured temperature is a representative of the actual temperature of the food item to be prepared.

[0124] Based on the execution of the long-term cooking template and the automatic transition, an automatic food preparation process is initiated which, without or at least with reduced interaction from a user, is able to prepare the food according to the recipe specified by the long-term cooking template.

[0125] According to an explanatory embodiment of the invention, said induction cooking system is a cooking system according to any of the paragraphs [0006]-[0086],

[0126] In an aspect, the invention relates to the use of an induction cooking hob for long-term cooking based on a long-term cooking template.

[0127] According to an explanatory embodiment of the invention, the induction cooking hob is comprised by an induction cooking system according to any of the preceding paragraphs.

The drawings

[0128] For a more complete understanding of this disclosure, reference is now made to the following brief description, taken in connection with the accompanying drawings and detailed description, wherein like reference numerals represent like parts. The drawings illustrate embodiment of the invention and elements of different drawings can be combined within the scope of the invention:

Fig. 1 illustrates an induction cooking system according to an embodiment of the invention,

Fig. 2a-c illustrates a cookware according to an embodiment of the invention,

Fig. 3 illustrates a flowchart of control of the induction cooking system, and

Fig. 4a-4c illustrated temperature and power curves of cooking according to different long-term cooking templates.

Detailed description

[0129] The present invention is described in view of exemplary embodiments only intended to illustrate the principles and implementation of the present invention. The skilled person will be able to provide several embodiments within the scope of the claims.

[0130] The induction cooking system 1 is illustrated in an embodiment of the invention on Fig. 1. The illustrated cooking system 1 comprises an induction hob 2 (sometimes simply referred to as hob) and an induction cookware 3 (sometimes simply referred to as cookware).

[0131] The induction hob 2 comprises a power supply 4 supplying a controller 5 and induction coils 6 from an external electric power source 19. The controller 5 is programmed to control the power to the induction coils 6 and thereby the heating of an induction cookware 3 placed at an area of the hob 1 covered by the induction coils 6 (sometimes referred to as coils). [0132] The hob 2 further comprises a user interface 7 via which the user may communicate with the controller 5 and thereby control the temperature development of heating of food items located inside the cookware 3. The user interface may be integrated in the hob 2 and implemented as a touch panel including a display for illustrating to a user which part of the hob 2 that is controlled and to what heating step of a predetermined number of heating steps that part is controlled.

[0133] The hob 2 may further comprise a wireless communication module 8 via which the induction system 1 is able to communicate (in embodiments bidirectionally) with an external control device 9 (sometimes simply referred to as external device) which may be portable such as a tablet, smartphone, smart speaker, cloud service, etc. The wireless communication module 8 may support one or more communication standards such as Wi-Fi, Bluetooth, Infrared, ultrasonic, etc. In this way the hob 2 can be controlled and / or configured from a local or remote location e.g. via a wireless network.

[0134] The controller 5 may be implemented as any suitable data processor or combination thereof such as a microprocessor or programmable logic controller. The controller 5 may comprise or communicate with a digital memory 10 from where the controller 5 may retrieve operation parameters, heating profiles, power levels at predefined heating steps, long-term cooking templates including recipes, etc.

[0135] As indicated, a hob 2 according to the present invention can be controlled according to a number of predefined heating steps each associated with a predefined power level for heating the cookware 3 positioned above the induction coils 6. In addition, to such traditional heating control, the hob 2 is able to heat a smart cookware 3 and thus perform intelligent / smart heating control.

[0136] Fig. 2a-c illustrates the smart cookware 3 of Fig. 1 in further details according to an embodiment of the invention. Fig. 2a illustrates a perspective view of the induction cookware 3, Fig. 2b illustrates an interior view of the induction cookware 3, and fig. 2c illustrates an inside view of a base part 11 of the induction cookware 3. [0137] The induction cookware 3 as seen in fig. 2a is an induction cooking pan in the form of a saucepan having a handle 12 but could be any type of cookware. The induction cookware 3 comprises a base part 11 which is the part of the induction cookware 3 that is placed on an induction hob 2 during cooking. As seen in Fig. 2b, the induction cookware 3 comprises a cooking surface 13, which is where the base part 11 comes into contact with food items 14 during cooking. The induction cookware 3 comprises a data processing unit 15, a transmitter 16 and a power supply 17 e.g. in the form of a battery, all arranged within the handle 12 of the induction cookware 1. Note that the power supply 17 is not limited to a battery, but could also completely or in part comprise an energy harvesting coil, capacitor, etc.

[0138] It should be noted that a digital memory (not illustrated) may also be included in the handle 12 either as a standalone module communicating with the data processing unit 15 or as part of the data processing unit 15. Note that the cookware may also comprise a dedicated compartment for enclosing the data processing unit 15, transmitter 16 and power supply 17 if not located in the handle.

[0139] The induction cookware 3 comprises one or more temperature sensors 18 (sometimes referred to simply as sensor) which is arranged preferably within the base part 11, as seen in fig. 2c. an alternative location of such sensors could be in the side of the cookware 3.

[0140] Accordingly, when a food item 14 is to be prepared, it is positioned on the cooking surface 13 and the cookware 3 is positioned on the hob 2. Then a user may use the user interface 7 to start a traditional cooking process by selecting one of a plurality of predetermined heating steps (e.g., 1-9, P or a “low power”). Alternatively, the user may use the external control device 9 to select one of the predetermined heating steps or power levels therebetween. Each of these heating steps is associated with a power level which may be stored in the memory 10. In addition, some hobs 2 also require selection of cooking zones.

[0141] In addition, according to the present invention, the user may prepare food items according to actual temperature of the food item even though only a temperature measurement from the sensor 18 is available. This is possible because of a so-called compensation model. With the compensation model, the actual temperature of the cooking surface 13 and / or the actual temperature of the food item being prepared, is determined based on a temperature measurement performed by the temperature sensor 18.

[0142] In the context of the present invention, a “compensation model” is understood as a model which associates a temperature measurement performed by the temperature sensor with an actual temperature of the induction cookware or as mentioned with the actual temperature of the food item. As an example, the actual temperature of the induction cookware may refer to a surface temperature of the base part of the induction cookware arranged to come into contact with food items to be cooked. For reasons concerned with reliability of the induction cookware, the temperature sensor may not be placed directly at the cooking surface 13 but may instead be placed adjacent thereto and measure temperature at a position on/in the induction cookware adjacent to (just below) the cooking surface 13. For that reason, a temperature reading of the temperature sensor 18 may not accurately reflect the actual temperature present on the cooking surface 13. The compensation model may amongst others (such as current and past heating) take into account a displacement of the temperature sensor from the cooking surface 13 and translate a temperature measurement of the temperature sensor 18 to a temperature value that is more representative of the actual temperature of the cooking surface 13.

[0143] As mentioned, the compensation model may in an embodiment associate the measurement from the sensor 18 with the actual temperature of the food item to be prepared. Hence, the average temperature of a soup, sauce, mash, etc., the core temperature of a steak, roast, etc. No matter if it is the actual temperature of the cooking surface 13 or of the food item, the association with the measured temperature may be established based on test cooking’s, simulations or modelling of cooking’s and the like. The compensation model may be stored in the digital memory of either the hob 2, the external device 9 and/or the cookware 3 and thus, the association between the measured and actual temperature may be performed by a controller of either the hob 2, the external device 9 and/or the cookware 3.

[0144] To be able to establish the actual temperature of the food item, the user need to provide information of the food item to the controller establishing the actual temperature. Such information may include type of food item, temperature of food item, thickness of steak, weight or diameter of a roast, volume of a soup, etc. The controller may then correlate this information with the measured temperature to establish the actual temperature. The correlation may in an embodiment include using the information to find a predetermined actual temperature matching the information in a look-up table. Alternatively, the correlation may include providing the information to an algorithm which may return the actual temperature. Alternatively, the correlation may include providing the information to a model and simulate a cooking based hereon to establish the actual temperature.

[0145] Furthermore, the compensation model may be a time-based compensation model taking into account latency in temperature development of the induction cookware 3. Latency refers to the fact that temperature response of the induction cookware 3 or food item 14 is not immediate. For example, as inductive power is supplied to the base part of the induction cookware 11 by an induction hob 2, the temperature sensor 18 measures an increasing temperature over time, however, when the power to the induction coils 6 is subsequently turned off, the temperature sensor 18 may still measure a temperature that is increasing over time. As a matter of fact, the measured temperature may increase more than twenty degrees Celsius once inductive power is turned off. If this latency is not adequately taken into account, it is evident that the cooking surface 13 and thereby the food item 14 may become hotter than intended resulting in overcooking of food items 14. Such overcooking may be critical for some food items such as hollandaise sauce or bearnaise sauce which may become split once a critical temperature has been reached. By taking into account the latency in the cookware 3, it may be possible to avoid e.g., such splitting of a sauce. From this it is evident that the compensation model enables for advantageous control of the induction cookware 3, as it may facilitate improved accuracy in the control of a cooking process (also sometimes referred to as food preparation process).

[0146] The compensation model may further be arranged to correlate the energy provided to the induction cookware through induction to a change of temperature of the induction cookware 3, such as a change of temperature of a cooking surface of the induction cookware 11. In other words, the model may simulate the temperature response of the induction cookware as inductive power is applied and thereby forecast how the cookware responds over time to e.g., a change in applied inductive power. For example, the model may predict a new equilibrium temperature achievable by increasing the inductive power a certain amount, and also predict the timing involved, i.e., how long time it takes to reach the new equilibrium temperature. This calculation may among others take into account heat losses of the inductive cookware. Correlating energy input to change of temperature is advantageous in that the compensation model then is able to estimate a specific power to be supplied to the inductive cookware in order to faster and more accurately reach a new equilibrium temperature.

[0147] As mentioned above, according to the present invention, the user may also select one of, preferably, a plurality of long-term cooking templates, e.g. via an application installed on the external control device 9. Below, an example, according to an embodiment of the invention, of using a long-term cooking template for preparing a food item 14 such as a steak is described with reference to the flow chart of Fig. 3. Other food items that may benefit from long-term cooking templates are egg, poultry, fish and vegetables such as potatoes, etc.

[0148] In a first step SI, if not already established, communication between the hob 2 and the cookware 3 and/or between the hob 2 and the external device 9 and/or between the cookware 3 and the external device 9 is established. The communication between the wireless communication module 8 of the hob 2, the transmitter (or transceiver) 16 of the cookware 3 and / or the external device 9 may be established e.g. using the Bluetooth Low Energy protocol. If such communication is established, step SI may be skipped. [0149] With communication between the devices 2, 3, 9 of the induction cooking system 1 established, a user may select a long-term cooking template, set (increase/decrease) the temperature of the food item 14 in steps of e.g. ± 1°C. Further, the user may follow the development of the actual temperature in the steak via a display on the external device 9 based on the compensation model specified above. In an embodiment, the colour development from rare to well done as the actual temperature increases may also be displayed to the user via the display of the external device 9.

[0150] It should be noted, that an additional sensor provided in direct contact with the food item may be used to supplement the above temperature estimation of the steak. In may either be used in the control of the heat and / or to establish a visual colour development in the display.

[0151] In a second step S2, the user selects the long-term cooking profile for roasting a steak.

[0152] In a third step S3, the controller 5 of the hob 2, based on the selected longterm cooking profile, regulates (increase or decrease) the power to the induction coils 6 so as to establish a target temperature and/or heating profile of the cooking surface 13 or of the food item 14 which is specified in the long-term cooking profile. In this particular example the target temperature is of the cooking surface 13.

[0153] It should be mentioned that an increase of power may be applied either as a stepwise increase or a continuous increase.

[0154] Slowly increasing the power may be advantageous in that the user may have time to observe and take action if needed. As an example if Ghee is to be prepared where water is heated away from butter the slowly increase of power may ensure less splash.

[0155] The regulation is based on temperature measured by the temperature sensor 18. This temperature is sent from the transmitter 16 of the cookware to the controller 5 of the induction hob. Note that communication may also be provided via the external device 9. [0156] In a fourth step S4, the controller 5 evaluates if the measured temperature has reached the target temperature. If not, the controller continues to increase/decrease power to the coils 6 in step 3 S3. If yes, the controller 5 evaluates if the target temperature is to be maintained or a second target temperature is to be reached. This evaluation is made based on the long-term cooking template.

[0157] It should be noted that the compensation model may be used in the control to establish the actual temperature of the food item based on the measured temperature. Thereby, it is possible to control the temperature overshoot. Hence, if an overshoot is allowed, a high power can be applied to the coils 6 thereby reaching the target temperature faster. If no overshoot is allowed, a lower power is applied to reduce or eliminate a temperature overshoot. Further, the compensation model may be used to regulate the measured temperature according to / to reach the actual temperature of the food item 14 or the cooking surface 13 temperature.

[0158] The user using the present invention to prepare food may initiate the cooking process by the boost function of the cooktop and then the temperature control takes over and control the power to obtain and maintain a desired temperature. Hence, the user do not need to push e.g. level 6 on the cooktop to maintain a boiling temperature. This is especially advantageous when a user is to use a new cooktop where the user does not know if e.g. level 6 is boiling temperature of a cookware comprising 1,5L of water with salt. This is especially the case where several users are using the same cooktop a few times such as in shared kitchens of a hostel or residence hall. Hence, by the temperature control of the present invention, overshoot of power / temperature may be reduced or eliminated and thus the residual heat is used instead, leading to a reduced energy consumption and a precise temperature of the cookware. The latter is important to some types of cooking processes where the food is ruined if the temperature is only a few degrees to high.

[0159] In a fifth step S5, the controller 5 evaluates if the recipe of the long-term cooking template specifies a second target temperature to be reached immediately after the first target temperature is reached. If yes, the temperature is regulated in step 3 S3 and the time duration used to reach the first target temperature may be referred to as a first heating period. If no, it is evaluated if the first target temperature must be maintained for a period of time.

[0160] In a sixth step S6, the controller 5 evaluates if the recipe of the long-term cooking template (sometimes referred to simply as recipe) specifies a time period of which the first target temperature (second target temperature if the cooking process has been in step 9) is to be maintained. If no, the food preparation process is ended in an eight step S8. If yes, the first target temperature is maintained.

[0161] In a seventh step S7, the first target temperature (second target temperature if the cooking process has been in step 9) is maintained for a period of time specified in the recipe. The time duration the first target temperature is maintained in step S7 may be referred to as a first heating period (second heating period if the cooking process has been in step 9). The controller 5 may establish the time by a built-in counter.

[0162] In a ninth step S9, the controller evaluates if the first target temperature is maintained for a time duration specified by the recipe. If not, the temperature is maintained in step S7. If the time has elapsed, the controller 5 evaluates if a second target temperature must be reached in step S5.

[0163] If this is not the situation, no temperature must be maintained in step S6 and the food preparation process ends in step S8.

[0164] If this is the situation, the temperature, i.e. power to the coils 6, is regulated to reach the second target temperature in step S3. Thus, the controller controls power to the coils 6 to reach and maintain the second target temperature as described above with respect to the first target temperature.

[0165] Note that while the above example is controlled by the controller 5, similar control may be carried out by the data processor of the portable device 9 which then may receive measured temperature from the sensor 18 and send power setpoints to the controller 5. The power setpoint may be a value calculated based on user input, predetermined values derived from the long-term cooking template, calculated based on actual power provided to the coil(s) from the hob 2 and temperature from the sensor 18, etc.

[0166] Fig. 4a - 4c illustrates different examples on temperature curves (dashed lines) and the associated power curve (solid line). The temperature and power levels of the two Y-axis are just examples to illustrate the preparation process of the food item according to a long-term cooking template. Also, the “broken” timeline of the X- axis is for exemplifying and thus all values on Fig. 4a - 4c are example values.

[0167] The temperature curve may be the temperature measured by the sensor 18 or the actual temperature of the food item established by the correction model. The power curve may be the power provided to the coils or coil (in hobs with only one coil available) 6.

[0168] In Fig. 4a, it is noted, that a high power (just above 2500W) is provided the first minute after which the power is reduced to a substantially steady state from the second minute and afterwards until just before 120 minutes, the power is shut off. The temperature curve and the power curve are linked so that when the temperature increases during the first 1-2 minutes the power curve is high. Subsequently, the power is regulated to maintain a substantially constant temperature until the power is shut off after which the temperature starts to decrease.

[0169] In Fig. 4a, a first heating period is defined as the time duration the maximum power level is supplied i.e. from start and to just over one minute into the cooking process. This first heating period may be referred to as the food heating period and may in other embodiments be longer or shorter.

[0170] The first heating period may be used to establish a crust / out surface of e.g. a steak as desired. A crust may be established after several hours (such as 4 hours) of long-term cooking at low temperature (such as between 55°C and 60°C, e.g. 57°C).

[0171] However, following the power curve illustrated in fig. 4b, the crust is made at the beginning of the long-term cooking process. The crust may be established e.g. by applying a high temperature (such as 200°C) for around one minute (on both sides of the steak). Such crust may than isolate the rest of the steak from the hot cookware so that the steak will be slowly prepared.

[0172] A second heating period is defined from when the first heating period ends and until the power provided to the coils are shut off. The second heating period may be referred to as a temperature maintaining period.

[0173] The power level may be specified by the long-term cooking template; however, the duration of the food heating period may be determined by the temperature measurement, i.e. when the temperature curve reaches a target temperature / threshold temperature specified by the long-term cooking template, the power level is changed. The duration of the temperature maintaining period may be specified by the long-term cooking template whereas the power level during this period may be determined based on the measured temperature so as to maintain a substantial constant temperature at a target temperature. Accordingly, the transition between heating periods may be controlled by e.g. the controller 5 based on input from the long-term cooking template.

[0174] Although the second heating period in fig. 4a comprises a power of around 1000 watts, it should be noted that this is only exemplary, and that other inductive powers may be utilized during the second heating period. For example, the second heating period may be power limited. The power supplied to the induction cookware may be limited to 250 watts, such as limited to 200 watts, such as limited to 150 watts 120 watts during the second heating period, thus inductive power supplied to the cookware may be in the range from 0 watts to 250 watts, such as in the range from 0 watts to 200 watts, such as in the range from 0 watts to 150 watts, such as in the range from 0 watts to 120 watts, during the second heating period, for example 100 watts. Preferably, the power is limited to 120 watts during the second heating period. Limiting the inductive power supplied in the second heating period to 120 watts is advantageous in that the temperature of the cookware is kept at a temperature sufficiently low to avoid that a fire may be started due to the cooking process. Thereby may be achieved an automatic execution of a long-term cooking template where the safety of the execution is improved. The use of such a power limit is particularly useful for carrying out a sous vide recipe. Such power limit may also be utilized in other embodiments of the invention, for example in embodiments according to figures 4b and 4c.

[0175] Fig. 4b illustrates a cooking process following a long-term cooking template different from the one illustrated in Fig. 4a. The main difference is that as illustrated in Fig. 4b, the first heating period / the food heating period includes two periods where “high” power is applied to the coils 6 (at 1 minute and between the third and fourth minute) leading to an increase in the measured temperature.

[0176] The second heating period / the temperature maintaining period is more or less similar to the temperature maintaining period illustrated in Fig. 4a.

[0177] Additional heating periods than those illustrated in Fig. 4a-4c may be said to exist such as a pre-heating period where the food item is thawed prior to heating. Further, a post-heating period may be said to exist where the prepared food item is e.g. covered up and put aside until eating or further preparation. These additional heating periods are not illustrated.

[0178] Fig. 4c illustrates a cooking process following a long-term cooking template including four heating periods. The first and third heating periods may be defined as food heating periods whereas the second heating period may be defined as the temperature maintaining period and the fourth heating period is a food finishing period. The food finishing period may be specified by the long-term cooking template as a period of time where the prepared food needs to rest before eating for further preparation.

[0179] With reference to Fig. 4a-4c, an example of a heating period of a long-term cooking template may be the time duration starting when taking the food item out of a fridge and letting its temperature rise towards ambient temperature such as towards e.g. 20 degrees. Alternatively, a heating period may be the time duration where the temperature of the food item may be increased slowly by providing only a minor power such as e.g. 150W to the coils 6. Alternatively, a heating period may be a time duration where the temperature of the food item rises faster by providing e.g. 2000W to the coils 6. Alternatively, a heating period may be a post heating period in that some food items for optimal preparation or for timing issues may benefit from being covered and put aside for a period of time either on the hob 2 with no power to the coils 6 or off the hob2. Hence, this non-limiting example of a cooking process according to a long-term cooking template includes three heating periods having the steps of OW, 150W and 2000W. It should be noted that the same heating period may include more than one power level.

[0180] Accordingly, the transition between heating periods may be defined by e.g. measured temperature, actual temperature (established via the correction model), etc. so that when a temperature is reached a heating period change. Alternatively, the transition between heating periods may be defined by a time period i.e. the end of one time period may end a heating period. Alternatively, the transition between heating periods may be defined by power levels provided to the coils 6 so that when a power level change, a heating period change.

[0181] An example of a temperature maintaining period may include a varying induction power to maintain the target temperature of the food substantially constant. The long-term cooking template may specify more than one target temperature that is to be maintained for a longer time (e.g. more than 10 minutes) during preparation of the food. In this case, a main temperature maintaining period may be divided in two or more temperature maintaining periods or the long-term cooking template may simply specify two or more individual temperature maintaining periods.

[0182] Since the duration of preparation of food according to a long-term cooking process may take several hours, when the long-term cooking process is selected, the controller is bypassing the automatic safety shut-off of the induction hob 2.

[0183] The long-term cooking template may be dynamic in that the temperatures and time durations may change depending on the use of a lid on the cookware or not. According to some long-term cooking templates, the lid is required for an optimal result of the cooking process.

[0184] Further, the long-term cooking template may be dynamic in that the start time or end time of the food preparation process may be specified by the user e.g. via the app of the external device 9. Hence, depending on the user defined start and / or end time and thereby the available time for the food preparation process, the temperatures and time durations may vary to obtain the optimal result of the cooking process.

[0185] Further, the long-term cooking template may be dynamic in that the target temperature of the food item may be specified by the user. Hence, in the example of a steak, the user may specify a temperature matching the user’ s taste such as medium or well done and the temperature and/or time durations may adapt to the specific user desire to the result of the cooking process.

[0186] In an example of a cooking process comprising a fluid, the long-term cooking template may include boiling the fluid to establish bubbles and thereby stirring of the fluid at predetermined times / temperatures during the cooking process.

[0187] In an embodiment, the induction cooking system 1 may comprise two induction hobs 2 both communicating with the external device 9 and/or the cookware. In this embodiment, the cooking process according to the long-term cooking template may start at one hob and end at the other hob. In this way, the parts of the cooking process where a given temperature is maintained for a longer period of time, can be processed on one hob and the parts requiring user interaction may be processed on the other hob.

[0188] The peak energy consumption may not be too high in that too high temperature may damage a coating of the cookware. This may be selected automatically by the controller from the information on the pot size, induction coil diameter and maximum power available.

[0189] In an embodiment, the user may be able to specify (e.g. via the external control device 9) a peak energy consumption to prevent a fuse in the external power system from burning if there is a risk of more electric loads are to be supplied from the same phase simultaneously. Further, the user may be able to specify a maximum level or temperature of the cooking surface of the induction cookware to protect a coating to such service. [0190] From the above it is now clear that the invention relates to a smart induction cooking system 1 facilitating data communication between an external device 9, a hob 2 and a cookware 3. According to a long-term cooking template, the induction cooking system 1 is able to control preparation of food items during two or more heating periods. At least one of the heating periods are counted minutes, preferably in hours and thus the long-term cooking template facilitates bypassing an auto-shut off function of the induction hob 2. The auto-shut off will normally shut off automatically depending on the power level selected by the user. Hence, as an example, the auto- shut-off feature will turn the coil(s) off after e.g. 1.5 hours on highest power level (e.g. level 9). Using a lower setting, e.g. power level 5 will increase this duration and make this duration turnoff after e.g. 3 hours, at a low setting such as power level 1 or 2 the duration may be 6 hours. The control of temperature / power levels and transition to obtain the optimal cooking result is autonomously controlled (i.e. without a user need to perform any regulation) by a controller of one of the external device 9, hob 2 or cookware 3.

[0191] Hence, the present invention allows a user to leave the induction hob unattended for several hours while the induction cooking system prepares a food item. The result of the cooking process is predictable and two subsequent executions of the same long-term cooking processes may lead to substantially the same cooking result. This is not possible by prior art cooking systems where only a power level and thus indirectly a temperature is maintained constant for a period of time.

[0192] The invention has been exemplified above with the purpose of illustration rather than limitation with reference to specific examples of methods and robot systems. Details such as a specific method and system structures have been provided in order to understand embodiments of the invention. Note that detailed descriptions of well-known systems, devices, circuits, and methods have been omitted so as to not obscure the description of the invention with unnecessary details. List of reference signs:

1 Induction cooking system

2 Induction hob

3 Induction cookware

4 Power supply

5 Controller

6 Induction coils

7 User interface

8 Wireless communication module

9 External control device

10 Digital memory

11 Base part of induction cookware

12 Handle of induction cookware

13 Cooking surface of induction cookware

14 Food item

15 Data processing unit of induction cookware

16 Transmitter of induction cookware

17 Power supply of induction cookware

18 Temperature sensor of induction cookware

19 External electric power source