Patent Application
20230080634
This application claims the benefit of priority to European Application No. 21195957.2, filed Sep. 10, 2021, the disclosure of which is incorporated in its entirety by reference herein.
The present disclosure relates to a method for preparing a food in a pot by means of a food processor with temperature control and a boiling detection unit, a corresponding food processor and a corresponding computer program product.
The cooking behavior depends on the measuring accuracy of the temperature sensor and the environmental conditions, e.g. geographical altitude, level of the medium in the pot and the quality of the mixture by stirring, for example. In principle, controlling to a target temperature during the boiling process involves the discrepancy that the boiling temperature is defined by the physical properties of the medium and the environmental conditions present. Thus, the control may not reach its target temperature at all under certain circumstances. Depending on the control algorithm for the temperature, it thus sets an undefined heating power, which then leads to varying, sometimes non-reproducible cooking results.
The foregoing features known from the prior art may be combined individually or in any combination with any of the objects and configurations of the present disclosure described below.
It is the task of the present disclosure to provide a further developed method together with a food processor.
A method according to the main claim as well as a food processor and a computer program product according to the additional claims serve to solve the task. Advantageous configurations result from the subclaims.
A method for preparing a food in a pot, in particular by means of a food processor comprising the pot, a heating element for heating the pot and/or a food in the pot and a temperature sensor for determining an actual temperature of the pot and/or the food in the pot, serves to solve the task. The method preferably comprises the following step: Performing a temperature control, in particular by a control device, in a temperature control mode based on a desired temperature by adjusting an electrical energy supplied to the heating element in dependence on the actual temperature, so that the actual temperature approaches or reaches the desired temperature. The method preferably comprises the following step: Detecting a predetermined boiling stage of the food by a boiling detection unit. The method comprises the following step: Changing, in particular from the temperature control mode, to a fixed mode of the control device, preferably when the boiling detection unit detects the predetermined boiling stage, wherein the electrical energy supplied to the heating element is kept at a fixed value in the fixed mode. In particular, the fixed value depends on the desired temperature, a user input, a digital recipe or a recipe step of a digital recipe.
In this way, a reproducible cooking result can be achieved particularly reliably with a system that has a reduced complexity.
In the following, exemplary embodiments of the present disclosure are also explained in more detail with reference to figures. Features of the exemplary embodiments may be combined individually or in a plurality with the claimed subject matter and disclosed aspects of the present disclosure, unless otherwise indicated. The claimed scopes of protection are not limited to the exemplary embodiments.
The figures show:
The food 20 in the pot 2 of
The pot 2 is made of glass or metal, in particular stainless steel, and/or has a thickness of 0.5 to 1.0 mm. The diameter of the pot 2 is preferably between 12 cm and 17 cm. In particular, the pot bottom 13 has a smaller diameter (e.g., 11 cm to 14 cm) than the pot 2 on the upper side (e.g., 15 to 17 cm). Preferably, the temperature sensor 4 is a thermistor preferably with a negative temperature coefficient.
During normal heating of a liquid food 20 in the pot 2 below the boiling point, i.e., without vapor formation, the supply of heat power by the heating element 3 causes the temperature in the food 20 to rise. When the boiling point is reached, a first portion of the supplied heat power offsets losses from effluent heat and an optional second portion of the supplied heat power is consumed almost entirely for a phase change from liquid to vapor while the temperature remains substantially constant.
In temperature control mode 19, the actual temperature TI is approximated to the desired temperature TT by adjusting the electrical energy supplied to the heating element 3 (in particular the electrical power in watts). In temperature control, the electrical energy supplied to the heating element 3 does not remain constant over the entire period in temperature control mode 19. In fixed mode 24, however, the electrical energy supplied to the heating element 3 is kept at a constant value (e.g. P1, P2 or P3 in
In one embodiment, the constant values (e.g., P1, P2, or P3 in
The constant value (P1, P2, P3) for the electrical energy to be supplied to the heating element 3 is in particular a power value, a current intensity value or a voltage value, or can be realized by means of a pulse control over a predefined time window, preferably 3 seconds. Preferably, the value for the electrical energy to be supplied to the heating element 3 is a reference variable and a control of the energy to be supplied to the heating element 3 takes place in order to obtain an approximately constant heat supply by the heating element 3 according to the reference variable. As explained above, the constant value of the fixed mode 24 can be described in such a way that a first part of the supplied thermal power compensates for losses from effluent heat and an optional second part of the supplied thermal power serves almost entirely for a phase transformation from liquid to vapor while the temperature remains substantially constant.
In particular, the value P1 for quiet boiling is defined such that the second part of the supplied heat power for phase transformation is approximately zero (or at most leads to a low steam rate of approximately 2 g/minute), so that mainly heat losses are compensated by the first part of the supplied heat power. The liquid food then behaves approximately like water at normal pressure with a temperature just below 100° C. Preferably, the value P1 is defined such that a steam rate of at least 0.5 and/or at most 3 g/minute on average, preferably about 1 g/minute is produced. In particular, the value P1 is associated with a boiling desired temperature (TT1), e.g. 98° C. or plurality of boiling desired temperatures, e.g. 95° C., 96° C., 97° C., 98° C. and 99° C. In one embodiment, it is also provided that the value P1 is associated with a boiling desired temperature ranges TTB of less than 100° C. and/or greater than 95° C. At the value P1, there is a formation of steam 22 and small bubbles 16 (cf.
In particular, the value P2 for a normal cooking is defined such that the second part of the supplied heat power for the phase transformation is so large that heat losses are compensated by the first part of the supplied heat power and the second part of the supplied heat power results in a phase transformation with clearly visible and audible bubbles rising from the pot bottom to the surface of the liquid food and bursting there. Preferably, the value P2 is defined such that a steam rate of at least 4 and/or at most 6 g/minute on average, preferably about 5 g/minute is produced. In particular, the value P2 is associated with a boiling desired temperature (TT2), e.g. 100° C. or plurality of boiling desired temperatures, e.g. 100° C., 101° C., 102° C., 103° C. and 104° C. In one embodiment, it is also provided that the value P2 is associated with a boiling desired temperature ranges TTB of at least 100° C. and/or at most 104° C. In one embodiment, the value P2 corresponds to at least two times the value P1 and/or the value P2 is less than four times the value P1. For example, the value P2 is an electrical power of 300 W.
In particular, the value P3 for strong cooking is defined such that the second part of the supplied heat power for the phase transformation is so large that heat losses are compensated by the first part of the supplied heat power and the second part of the supplied heat power results in a phase transformation with clearly visible and audible bubbles rising from the pot bottom to the surface of the liquid food and bursting there. Preferably, the value P3 is defined such that a steam rate of at least 6 and/or at most 9 g/minute on average, preferably about 7.5 g/minute is produced. In particular, the value P3 is associated with a boiling desired temperature (TT3), e.g. 105° C. or a plurality of boiling desired temperatures, e.g. 105° C., 106° C., 107° C., 108° C. and 109° C. In one embodiment, it is also provided that the value P1 is associated with a boiling desired temperature ranges TTB of at least 105° C. and/or at most 109° C. In one embodiment, the value P3 is at least three times the value P1 and/or greater than the value P2. For example, the value P3 is then an electrical power of 400 W.
In step 30, it is checked whether the desired temperature TT lies within a boiling desired temperature range TTB. The boiling desired temperature range TTB is preferably limited by a lower range limit of 98° C. and/or an upper range limit of 105° C. Thus, it is detected if a desired temperature is present for which the fixed mode 24 is provided.
If the condition of step 30 is not fulfilled, a conventional temperature control is performed, which will be discussed in more detail in connection with
In step 31 it is checked whether the actual temperature TI is less than the minimum temperature TMin (preferably 91° C.). If yes (Y), the heating element 3 is supplied with electrical energy at maximum power P100% (in particular 900 to 1000 W). If no (N), it is continued with step 32.
In step 32 it is checked whether the actual temperature TI is greater than the maximum temperature TMax (preferably 110° C.). If yes (Y), the power supply of heating element 3 is stopped, i.e. power P0% is set to zero. If, for example, all the liquid has evaporated, this case may occur. In ordinary heating, the check will usually give the result No (N), so continue with step 33.
By the fact that in step 31 a transition is made to step 32 and then, as a rule, immediately to step 33 already at an actual temperature TI greater than preferably 91° C. it can be prevented that the condition of step 32 is not fulfilled at all, and consequently the change to fixed mode 24 is not made, e.g. in the mountains at an altitude where water is already boiling at 91° C., or for other environmental reasons.
In step 33, the boiling stage criterion 15 is checked, which is also explained in more detail with reference to the other exemplary embodiment of
If the boiling stage criterion 15 is not fulfilled, in step 36 the heating element 3 is either supplied with maximum power P100%, because the boiling stage does not yet seem to have been reached, or a fine adjustment of the power to be supplied to the heating element 3 is changed in order to approximate the desired temperature TT even more precisely. With such a fine adjustment, electrical powers between 0% and 100% of the maximum power are also possible. In particular, a fuzzy logic is used for the fine adjustment.
If the boiling stage criterion 15 is fulfilled, it is switched to the fixed mode 24 and in step 34, the boiling detection unit (14) selects one of a plurality of fixed values P1, P2 for the electrical power for the heating element 3 in dependence on the desired temperature TT—and/or a user input, a digital recipe and/or a recipe step—so that a constant heat supply is generated by the heating element 3. Specifically, the heating element 3 is driven with the electrical power P1 (e.g. 100 W), the desired temperature TT is equal to the boiling desired temperature TT1 (e.g. 98° C.) because the value P1 in the memory 12 of the control device 10 is associated with the boiling desired temperature TT1. If the desired temperature TT is equal to the boiling desired temperature TT2 (e.g. 100° C.), the heating element 3 is driven with the electrical power P2 (e.g. 300 W) to which P1 in the memory 12 of the control device 10 is associated. Optionally, further fixed values such as P3 may be stored. Alternatively, the fixed value for a fixed, constant electrical power and/or heat output of the heating element 3 can be determined and applied by means of a permanently stored function or by interpolation of permanently stored reference values depending on the desired temperature TT, which is within the boiling desired temperature range TTB.
Then, in step 35, in a clock cycle that is preferably 3 seconds, the actual temperature is compared to the minimum temperature TMin (preferably 91° C.) and the maximum temperature TMax (preferably 110° C.). If the actual temperature TI leaves this temperature range or if the desired temperature TT changes (not shown in
Unlike the exemplary embodiment of
In step 41 it is checked whether the actual temperature TI is less than the desired temperature TT minus a range B for fine adjustment. If the condition of step 41 is not fulfilled (N), heating is performed with maximum power via heating element 3. In particular, B is between 5 and 15° C. Preferably, B=10° C. If, for example, a desired temperature TT of 105° C. is present, the condition of step 41 is just fulfilled when 95° C. is reached (Y).
If, for example, a desired temperature TT of 98° C. is present, the condition of step 41 is just fulfilled when 88° C. is reached (Y). Although 88° C. is not yet close to the boiling temperature, e.g. at normal pressure, heating will nevertheless be carried out with a comparatively low power P1 in the further course of the diagram. But this disadvantage of a long duration to reach the desired boiling state is accepted to realize a simple and reliable system.
In step 42, it is checked whether the actual temperature TI is greater than the desired temperature TT plus a range B for fine adjustment. In particular, B is between 5 and 15° C. Preferably, B=10° C. If, for example, a desired temperature TT of 105° C. is present, the condition of step 41 is not fulfilled only when an actual temperature of 115° C. is present (Y). As explained above in connection with
If the condition of step 42 is not fulfilled (N), which is the normal case, the desired temperature TT is compared in step 37 with stored boiling desired temperatures TT1, TT2, TT3 or with stored boiling desired temperature ranges TTB and, if this condition is fulfilled, the process is continued with step 33. In one embodiment, where the desired temperature TT is specified by a digital recipe or recipe step such that the desired temperature TT specifically corresponds to one of the stored boiling desired temperatures TT1, TT2, TT3, the boiling desired temperature TT1, TT2, TT3 of the desired boiling state is thereby specified. In an alternative embodiment, the value P1, P2, P3 of step 34 is directly specified by a user input, digital recipe or recipe step and it is continued with step 33.
If a lowest boiling desired temperature TT1 is e.g. 98° C. or a lower limit of a boiling desired temperature range TTB is e.g. 95° C., the condition of step 37 is not fulfilled e.g. at a desired temperature TT of 93° C. Step 37 has been reached because an actual temperature TI of 85° C., for example, is present. In this numerical example a normal temperature control takes place. A change to the fixed mode 24 is also not desired. Because the condition of step 37 is not fulfilled (N), it is continued with step 38.
Step 38 may comprise either a maximum power P100%, a fixed power for heating the pot 2 between P0% and P100% (e.g. 50% of the maximum power for a slower convergence to the desired temperature) or a fine adjustment of the power for the heating element 3. Preferably, step 38 includes logic for fine-tuning, in particular using fuzzy logic. A variable, electrical power is determined, with which the heating element 3 is controlled depending on the difference between the desired temperature TT and the actual temperature TI, preferably in a time window of about 3 seconds.
If, on the other hand, the condition of step 37 is fulfilled and a desired temperature TT is present for which the fixed mode 24 has been configured, it is continued with step 33. A change to fixed mode 24 then takes place.
In step 33 it is checked if the boiling stage criterion 15 is fulfilled. In particular, a first condition of the boiling stage criterion 15 is that a slope ΔTI/Δt of the actual temperature TI over the time t is below a predefined slope threshold DTS. For this purpose, a moving average of the derivative of the actual temperature TI over the time t is preferably formed, preferably over a period of less than one minute. In particular, the predefined slope threshold DTS is approximately 0.5° C./minute.
If a boiling desired temperature TT1 or a boiling desired temperature range TTB of below 100° C. is stored, a second condition of the boiling stage criterion 15 can preferably be checked in step 33. In particular, an OR operation is then provided between the second condition and the first condition, such that step 33 is fulfilled when one of the two conditions is fulfilled. In particular, in the second condition, it is checked whether the absolute number (i.e., sign always >0) of a difference between the actual temperature TI and the desired temperature TT is not greater than 2° C. for a predefined time period ZT. Preferably, the predefined time period ZT=1 minute.
If the condition or conditions of step 33 are not yet fulfilled, the temperature control is continued via step 38.
On the other hand, if the condition or conditions of step 33 are fulfilled, the boiling desired temperature TTi or TT1, TT2, TT3 identified in step 37 or a boiling desired temperature range TTB identified in step 37 is associated with a corresponding value P1, P2, P3, in particular according to a stored association or association logic of the boiling detection unit 14. Alternatively or additionally, the value P1, P2, P3 may be specified by a user input, a digital recipe and/or a recipe step. The heating element 3 is then supplied with electrical energy in step 34 according to the associated value P1, P2, P3. In particular, the value is the electrical power or desired power for the heating element 3. The system is now in fixed mode 24. The heating element 3 dispenses a substantially constant heat output to the pot 2.
For example, the value P1 specified above for quiet boiling is associated with the boiling desired temperature TT1=98° C., which corresponds to the current desired temperature TT. The heating element 3 is then supplied with a constant electrical energy of e.g. 100 W, which normally compensates the expected heat losses just below the boiling point and maintains this desired, quiet boiling state.
In step 35, the actual temperature TI is compared with a lower limit, the minimum temperature TMIN of e.g. 91° C., and/or an upper limit, the maximum temperature TMAX of e.g. 110° C., in a regular clock cycle of a few seconds. By this it is detected if the actual temperature TI leaves the boiling stage. If it is detected that the actual temperature TI leaves the boiling stage, it is switched back to temperature control mode 19 and the temperature control described above is continued.
In particular, in step 35 it is additionally checked (with an OR operation) whether the desired temperature TT has changed. Therefore, a change of the desired temperature TT, e.g. by the user or a recipe step of a digital cooking recipe, also leads to a change back to temperature control mode 19. For example, if the boiling process is to be terminated, the desired temperature TT is changed to zero, i.e. P0%. The system then changes from fixed mode 24 to temperature control mode 19.
In an alternative embodiment, the exemplary embodiment of
In all of the exemplary embodiments described above, the control device, e.g., the control device 10 of the food processor 1 of
A boiling detection unit 14 for detecting a predetermined boiling stage of the food 20 on the basis of a boiling stage criterion 15 is provided and the control device 10 is configured such that the control device 10 changes from the temperature control mode 19 to a fixed mode 24 when the boiling detection unit 14 detects the predetermined boiling stage, wherein the electrical energy supplied to the heating element 3 is kept in the fixed mode 24 at a fixed value P1, P2, P3, which is dependent on the desired temperature TT. In particular, the boiling detection unit 14 is part of the control device 10.
The power control is therefore only activated in certain temperature ranges around the boiling point and is switched back to temperature control when the temperature ranges are left. The boiling state is recognized, for example, by the fact that the measured temperature has a low slope or remains within a certain target temperature range for a certain time. In one embodiment, the following conditions are provided for the boiling stage criterion 15: The desired temperature specified in particular by the user or the digital recipe is between 98° C. and 105° C. or alternatively matches certain temperature values such as 98° C., 100° C. and 105° C. The measured actual temperature is greater than or equal to 91° C. (e.g. to cover a boiling point of water at 2000 m altitude of 93° C.) and less than 110° C. The measured actual temperature further has no positive slope >0.5° C./min for 30 s. Optionally, a further, in particular AND-linked condition may be that the heating power is >500 W. An OR-linked condition is further that the measured actual temperature for 1 min is in the range +/−2° C. around the desired temperature, in particular for desired temperatures <100° C. (e.g. 98° C.). If the actual temperature is <91° C. (in particular for longer than 30 s) or >110° C., it is switched back from the fixed mode to the temperature control mode. Optionally, in particular with an OR operation, it can be provided that it is switched back from the fixed mode to the temperature control mode if the slope is >+6° C./min or <−6° C./min, in particular over a period of time or a moving average value of the actual temperature over the time of preferably 10 s. An event of a sudden addition of a cold or hot medium can be considered in an improved manner in this way.
In the temperature range of boiling or cooking of the liquid food or water, the temperature control is replaced by a constant power supply and/or heat supply by the heating element. The boiling or cooking behavior achieved in this way corresponds in an improved manner to the typical user expectation and produces a cooking behavior in the pot 2 that corresponds approximately to the expected cooking on a stove in this temperature range at normal pressure.
The exemplary embodiments explained above all make it possible to achieve a reproducible cooking result and a desired steam rate particularly reliably with a particularly simple, not very complex system. For many dishes, the correct consistency is only achieved when a certain amount of water has evaporated in a controlled manner, e.g. in the case of red cabbage.
The present disclosure is based on the realization that, contrary to expectations, temporary deviations and minor deviations from a desired state of the food hardly affect the reproducibility of the cooking result in order to reliably achieve a reproducible cooking result. Up to now, methods and food processors pursuing the goal of reliably achieving a reproducible cooking result have been characterized by a very complex control in order to detect and correct as far as possible any deviation from a time-resolved planned state during the entire food preparation process.
In contrast to that, in particular around the boiling stage of the food, operation is carried out with a constant electrical energy supplied to the heating element. Tests have shown that influencing variables such as filling quantities or the quality of the mixture, e.g. by stirring, have no significant influence on the reproducibility of the cooking result if a fixed, in particular predefined value for the electrical energy supplied to the heating element is applied from the time the predetermined boiling stage is detected.
If, in one embodiment, a user or digital recipe specifies a desired temperature of 95° C. or 98° C.—alternatively between 95° C. and 99° C.—with the expectation of obtaining a quiet boiling state of the water in the pot with slight steam formation but still without (appreciable) bubbling, this state of the water and/or food can be achieved with a predefined constant first value of electrical energy or power, e.g. 100 watts, substantially independent of the height above sea level and substantially independent of the degree of filling of the pot. The same applies if, in an alternative embodiment, the user provides a corresponding user input with a corresponding desired boiling stage, e.g. boiling just before steam bubbling, via the user interface of the food processor or this is specified by a digital recipe or recipe step of a digital recipe.
If, in one embodiment, a user or digital recipe specifies a desired temperature of 100° C.—alternatively between 100° C. and 104° C.—with the expectation of obtaining a boiling state of the water in the pot with usual, normal steam formation and bubbling of boiling water, this state of the water and/or food can also be achieved substantially independently of the above-mentioned influencing variables with a predefined, constant second value of electrical energy or power, e.g. 300 watts, that is greater than the first value. The same applies if, in an alternative embodiment, the user makes a corresponding user input with a corresponding desired boiling stage, e.g. normal cooking with regular steam bubbling, via the user interface of the food processor or this is specified by a digital recipe or recipe step of a digital recipe.
If, in one embodiment, a user or digital recipe specify a desired temperature of 105° C. or greater with the expectation of obtaining a strong boiling state of the water in the pot with excessive steam formation and excessive bubbling, this state of the water and/or food can also be achieved substantially independently of the above influencing variables with a predefined, constant third value of electrical energy or power, e.g. 400 watts, that is greater than the second value, but in particular less than a maximum possible electrical energy or power. The same applies if, in an alternative embodiment, the user makes a corresponding user input with a correspondingly desired boiling stage, e.g. strong cooking with strong steam bubble formation, via the user interface of the food processor or this is specified by a digital recipe or a recipe step of a digital recipe.
In one embodiment, the fixed value for a constant electrical energy or power to be supplied to the heating element, i.e. for a constant heat output, can be determined and applied by means of a permanently stored function or by interpolation of permanently stored reference values depending on the desired temperature TT, which is within a boiling desired temperature range.
As mentioned above, it was recognized that for the reproducibility of the cooking result, influencing factors such as filling level, altitude above sea level or the food composition may lead to a slight temperature shift compared to the desired temperature. However, contrary to expectations, these influences and temperature shifts do not lead to a noticeable impairment of the desired, reproducible cooking result at the end of the food preparation process, which is of good quality in the evaluation by an average user.
On the contrary, the fixed mode with a fixed, constant energy supply to the heating element from the detection of the predetermined boiling stage often fulfills the user's expectation of the state of the boiling water and/or food even more reliably than a temperature control which normally fails in a region at a particular height above sea level because the boiling point there is correspondingly lower than 100° C. due to the lower ambient pressure. In order to implement a conventional temperature control without errors even at lower ambient pressures, an ambient pressure sensor with corresponding evaluation electronics and an inclusion of its sensor measurements in the temperature control would be required, i.e., a higher complexity of the system. Another example is a pot that is contaminated in the area of the temperature sensor, which may lead to the temperature sensor always measuring a lower temperature than is actually present. Here, too, the conventional temperature control may fail, whereas using the fixed mode can achieve the desired condition in the pot and the desired, reproducible cooking result can be achieved particularly reliably.
In the embodiment in which the electrical energy supplied to the heating element in the fixed mode is kept at a fixed value that depends on a user input, the user input is made by the user and/or transmitted to the control device via a user interface, in particular of the food processor. A user input may be implemented by means of a selection field by which the user may select one desired boiling stage from a plurality of boiling stages—for example, for a boiling just before steam bubbling, for a normal cooking with regular steam bubbling, or for a strong cooking with strong steam bubbling. In particular, the selection field may describe the boiling stages to be selected between by means of text and/or graphics. In one embodiment, the boiling stages to be selected between can each be a digital recipe that can be selected from a list of recipes.
In the embodiment in which the electrical energy supplied to the heating element in the fixed mode is kept at a fixed value specified by a digital recipe or a recipe step of a digital recipe, this specification is transmitted to the control device and/or implemented by the control device in the execution of a recipe or recipe step.
A further aspect of the present disclosure relates to a food processor configured such that the food processor performs or can perform the method according to the method described at the beginning. A food processor for preparing a food in a pot is provided, wherein the food processor comprises the pot, a heating element for heating the pot and/or a food in the pot, and a temperature sensor for determining an actual temperature of the pot and/or a food in the pot. The food processor may further comprise a tool for mixing and/or chopping a food in the pot. A control device is configured such that, in a temperature control mode, the control device can perform temperature control based on a desired temperature by adjusting an electrical energy supplied to the heating element in response to the actual temperature so that the actual temperature approaches or reaches the desired temperature. The food processor comprises a boiling detection unit for detecting a predetermined boiling stage of the food, and the control device is configured such that the control device changes from the temperature control mode to a fixed mode when the boiling detection unit detects the predetermined boiling stage, wherein the electrical energy supplied to the heating element in the fixed mode is kept at a fixed value that is dependent on the desired temperature. The definitions, configurations and effects of the aspect of the present disclosure described above are also applicable to this aspect of the present disclosure.
A further aspect of the present disclosure relates to a food processor. In particular, the food processor is configured such that the food processor can perform the method according to one of the preceding claims. For preparing a food in a pot, the food processor comprises the pot and a heating element for heating the pot and/or a food in the pot. The food processor further comprises a control device, a user interface, and a temperature sensor for determining an actual temperature of the pot or the food in the pot. The control device is configured such that, in a fixed mode, an electrical energy supplied to the heating element is kept at a fixed value when a user makes a user input via a user interface to enter a desired boiling stage, e.g., for boiling just before steam bubbling, for normal cooking with regular steam bubbling, or for strong cooking with strong steam bubbling. In other words, this user input results in a change or activation of the fixed mode. A reproducible cooking result can be achieved in this way particularly reliably with a system that has a reduced complexity. A desired boiling stage is a desired boiling state. In one embodiment, the desired temperature is defined by the desired boiling stage of the user input.
A further aspect of the present disclosure relates to a computer program product comprising instructions which, when the program of the computer program product is executed by a processor, in particular of a control device, preferably of a food processor, cause the processor to perform the steps of the method according to the aspect of the present disclosure described at the beginning.
The following definitions, configurations and effects apply to both the method and to the food processor, and may also apply to the computer program product.
A food processor is a food preparation device that can prepare a food by heating or mixing or chopping. This can be performed by manual operation by a user or by automatic execution of a stored recipe or individual recipe steps. The boiling point detection device of the food processor may be comprised by the control device of the food processor. The boiling point detection device and/or part of the control device may, for example, be outsourced to an external computing unit (such as a cloud computer, server, smartphone or tablet PC) that is communicatively connected to the control device of the food processor. A desired temperature or user input for the desired boiling stage may be specified, for example, by a user via a user interface, which is in particular comprised by the food processor, or by a digital recipe. A digital recipe is a data set defining a plurality of recipe steps. A recipe step may comprise control commands and/or cooking parameters for one or a plurality of electrically operable functional components of the food processor. These individual recipe steps are then executed automatically or semi-automatically. For example, a recipe step may specify a desired temperature. The control device then operates the heating element, for example, on the basis of the desired temperature. An electrical energy supplied to the heating element can be kept to a fixed value in the fixed mode by controlling the heating element with a constant target value for the energy to be supplied. In one embodiment, a power control is provided so that the electrical energy supplied to the heating element, e.g., an actual power, is as close as possible to or equal to the target power, e.g., a target power. If the food processor also comprises a tool for mixing and/or chopping, the control device may also control the tool. The control device then transmits control commands and/or signals to a drive whose electric motor rotates the tool. A temperature sensor for determining an actual temperature transmits digital or analog signals correlating to the measured temperatures to the control device. Either the control device determines the actual temperature by receiving the signals from the sensor or by receiving and signal processing the received signals from the sensor.
A boiling stage is a state of a liquid or water-containing food or water in the pot, in which a phase transformation from liquid to gaseous occurs at least partially due to heating by the heating element. Preferably, the predetermined boiling stage, which is defined in particular by means of a boiling stage criterion that may comprise one or a plurality of conditions, is defined in such a way that in the predetermined boiling stage steam bubbles rise from the pot bottom to the surface of the liquid food and burst there audibly to the human ear and release steam.
In general, control (closed-loop control) means that a controlled variable (e.g. actual temperature TI) and a reference variable (e.g. desired temperature TT) are compared with each other in a control loop and, depending on the difference between the reference variable and the controlled variable, a manipulated variable (e.g. electrical energy, in particular electrical power, to be supplied to the heating element) is adjusted such that the controlled variable approaches the reference variable.
At 100° C., the so-called boiling point, water begins to evaporate at normal pressure, i.e. approx. 1 bar ambient pressure. The boiling temperature depends on the altitude above sea level. The higher above sea level cooking takes place, the sooner the water begins to boil. For the preparation of food, a distinction is often made between so-called “silent boiling” and loud boiling, which is also referred to as cooking (e.g. boiling water). When a liquid food is heated, silent boiling begins first. At temperatures as low as approx. 90° C. or 95° C., small bubbles with water vapor form at the bottom of the pot which slowly rise to the top and burst at the surface. Only when the temperature is the same throughout the entire pot, the so-called cooking or loud boiling begins, during which the large steam bubbles audibly burst at the water surface. Sensitive foods such as sausages, dumplings, fresh ravioli or gnocchi heated in boiling water should be prepared in still boiling water with regard to an improved cooking result in terms of quality and reproducibility. At normal pressure, an average water temperature of 90° C. already leads to rising air bubbles accompanied by steam formation due to heating of the pot bottom. At 95° C., liquid water increasingly evaporates to steam. At 100° C., water evaporates at high speed. Foods such as potatoes are cooked in normal boiling water and foods such as red cabbage are cooked in strong boiling water with a high steam rate with regard to an improved cooking result in terms of quality and reproducibility.
In a configuration of the method and/or a configuration of the control device, it is provided that it is checked whether the desired temperature corresponds to one of a plurality of predefined boiling desired temperatures or falls within a predefined boiling desired temperature range. In this way, an expected boiling state of the food can be obtained particularly reliably with a not very complex system. In particular, this check is a condition of a boiling stage criterion, preferably an AND-linked condition, which in one embodiment can be brought forward to one or a plurality of steps at the beginning or during a temperature control. The complexity of the system can thus be further reduced.
In a configuration of the method and/or a configuration of the control device, it is provided that a first predefined boiling desired temperature (e.g. TT1=91° C.), which is less than 100° C., is associated with a first value (e.g. P1) for the electrical energy supplied to the heating element. In one configuration, it is provided that a second predefined boiling desired temperature (e.g. TT2=100° C.), which is greater than or equal to 100° C., is associated with a second value (e.g. P2) for the electrical energy supplied to the heating element. In one configuration, it is provided that a third predefined boiling desired temperature (e.g. TT3=105° C.), which is greater than 100° C., is associated with a third value (e.g. P3) for the electrical energy supplied to the heating element. In one configuration, at least two, preferably at least or exactly three, and/or at most eight, particularly preferably at most five, predefined values for the electrical energy supplied to the heating element are associated to a respective boiling desired temperature or a respective boiling desired temperature range. In this way, an expected boiling state of the food can be obtained particularly reliably with a not very complex system.
By “value for the electrical energy supplied to the heating element” is meant a parameter for controlling the heating element, which should cause a constant heating power of the heating element.
Preferably, the value for the electrical energy supplied to the heating element is predefined and/or stored in a memory together with the associated boiling desired temperature or the boiling desired temperature range. Particularly preferably, the value includes the electrical power to be supplied to the heating element. The parameter is then the electrical power, which can be specified with the unit watt, or a digital or analog signal value correlating therewith for controlling the heating element. If the electrical power supplied to the heating element is controlled to a desired power value, the value is this desired power value. Alternatively, the value may be a measure of the current supplied to the heating element that correlates with the heating power to be delivered by the heating element.
In one configuration, the plurality of predefined boiling desired temperature ranges are not below 95° C. In one configuration, the predefined boiling desired temperature range is not below 95° C. or the predefined boiling desired temperature ranges are not below 95° C. The complexity of the system can thus be further reduced.
In a configuration of the method and/or a configuration of the control device, it is provided that it is checked that the actual temperature is greater than a predefined minimum temperature and/or less than a predefined maximum temperature. A not very complex system, which particularly reliably enables a reproducible cooking result, can be obtained in this way. In particular, this check is a condition of a boiling stage criterion, especially an AND-linked condition, which in one embodiment can be brought forward to one or a plurality of steps during a temperature control. The complexity of the system can thus be further reduced.
In one configuration, the predefined minimum temperature (TMin) is at least 80° C. and/or at most 91° C. or 93° C., particularly preferably exactly 91° C. In one configuration, the predefined maximum temperature (TMax) is greater than 105° C. or 110° C. and/or less than 120° C. Particularly preferably, the predefined maximum temperature is 110° C. In this way, the system can be operated in the fixed mode for a particularly long time and computing capacity can be saved. A slow response time of the system is accepted, because it was recognized that this has no significant influence on the quality and reproducibility of the cooking result and the system can be simplified and computing capacity can be saved. This advantage also applies to at least the following two configurations.
In a configuration of the method and/or a configuration of the control device, it is provided that the control device changes from the fixed mode back to the temperature control mode if the actual temperature falls below the predefined minimum temperature or exceeds the predefined maximum temperature. In one embodiment, it is additionally provided that the control device changes from the fixed mode back to the temperature control mode when a change of the desired temperature occurs.
In a configuration of the method and/or a configuration of the control device, it is provided that in the temperature control mode the electrical energy supplied to the heating element is controlled to the value zero (P0%) if the actual temperature exceeds the predefined maximum temperature, and/or the electrical energy supplied to the heating element is raised to a heating value or a maximum possible value (P100%) if the actual temperature falls below the predefined minimum temperature. A heat-up value is between the value zero (P0%) and the maximum possible value (P100%)
In one configuration of the method and/or a configuration of the control device, it is provided that a boiling stage criterion is checked to detect the predetermined boiling stage, wherein the boiling stage criterion comprises at least one predefined condition. Thus, only one condition may already be sufficient. Preferably, however, there are a plurality of conditions, but in particular not more than eight conditions.
In one embodiment, the boiling stage criterion is defined such that the boiling stage criterion can be checked exclusively on the basis of the actual temperature or the measurement data of the temperature sensor, i.e. on the basis of the preferably time-resolved signals supplied by the temperature sensor for detecting the actual temperature.
In one configuration, the boiling stage criterion comprises the following condition: a slope (ΔTI/Δt) of the actual temperature (TI) over time (t) falls below a predefined slope threshold. A slope is a difference of two actual temperatures over the time difference of the measurement of these two actual temperatures. A slope corresponds to the first derivative of a function TI(t) of the actual temperature as a function of time. In one embodiment, the actual temperature (TI) is a moving average. A moving average averages over a plurality of signals of the actual temperature measured by the temperature sensor to provide the actual temperature for checking the boiling stage criterion. Preferably, the time period over which the moving average is averaged is at least 5 seconds and/or at most 1 minute, most preferably 0.5 minutes. Problems caused by measurement inaccuracies and other fluctuations due to external influences can thus be prevented and a particularly reliable detection of the boiling stage can be enabled.
In one configuration, the predefined slope threshold is at least 0.2° C./minute and/or at most 5° C./minute, particularly preferably about 0.5° C./minute. A particularly reliable detection of a boiling stage of the food can thus be achieved.
In one configuration, the boiling stage criterion comprises the following condition if a boiling desired temperature that is less than 100° C. is stored: the amount of a difference between the actual temperature and the desired temperature is not greater than at least 1° C. and/or at most 5° C., particularly preferably not greater than about 2° C., for a predefined period of time. In other words, a symmetrical, concurrent tolerance band is provided around the desired temperature, and the condition of the boiling stage criterion is fulfilled if the actual temperature value does not leave the tolerance band for the predefined time period. In particular, this condition can be provided with an OR operation in addition to the above-described condition relating to the slope. This enables even more reliable detection of the boiling stage.
In one configuration, the predefined time period is at least 0.5 minutes and/or at most 10 minutes, particularly preferably about one minute.
In one configuration, a clock cycle is at least 1 second, preferably 3 seconds, particularly preferably at least 5 seconds, and/or at most 30 seconds, particularly preferably at most 10 seconds. Preferably, the clock cycle is exactly 5 seconds. In particular, the clock cycle is applied in fixed mode. A checking of, for example, the actual temperature against one or a plurality of temperature limits then takes place regularly at a time interval of the clock cycle. Again, a slow response time of the system is accepted, because it was recognized that this has no significant influence on the quality and reproducibility of the cooking result and the system can be simplified and computing power can be saved by this.
In one configuration, it is provided that in the fixed mode of the control device the fixed value of the electrical energy supplied to the heating element is dependent on the desired temperature, a user input or a digital recipe, in particular on a recipe step of the digital recipe. In particular, a desired boiling state can be specified or selected by the user input or a digital recipe, based on which the corresponding fixed value of electrical energy for the heating element is then used by the control unit to achieve this boiling state. In this way, a reproducible cooking result can be achieved particularly reliably with a system that has a reduced complexity.
In one configuration it is provided that in the fixed mode of the control device the fixed value of the electrical energy supplied to the heating element is specified by a user input or a digital recipe, in particular by a recipe step of the digital recipe. For users, this provides a possibility to specify a fixed value of electrical energy for the heating element, even under special environmental conditions, which are adapted to these special environmental conditions to achieve the desired boiling state. A digital recipe or a recipe step of a digital recipe can in this way directly and specifically effect the desired boiling state. In this way, a reproducible cooking result can be achieved particularly reliably with a system that has a reduced complexity.
| Number | Date | Country | Kind |
|---|---|---|---|
| 21195957.2 | Sep 2021 | EP | regional |
