EP2211591B1 - Method for operating a hob with a number of heating elements - Google Patents

Abstract

The method involves detecting an operation which has the removal of cooking utensil element (12) from an opening position (20) and the adjacent positioning of the cooking utensil element in an end position (22). The heating zone (16) is displaced in the area of the end position in connection with the detected operation.

Description

The invention relates to a method for operating a hob according to the preamble of claim 1 and a hob with a plurality of heating elements according to the preamble of claim 11.

So-called matrix cooktops with a multiplicity of small and identically constructed heating elements are known from the state of the art, which are arranged in a grid. One of the distinguishing features of such cooktops is the ability to form from one or more such heating elements a flexible heating zone adapted to the size, shape and position of a cookware element placed on the cooktop. The user can therefore position the cookware element largely freely, and the assignment of different heating elements, in particular inductors of an induction hob, to the cookware element is automatically such that those heating elements that can heat the cookware element most effectively, this cookware element or on this cookware element be assigned adapted heating zone.

The detection of the shape, size and position of the cooking utensil element is usually not continuous, but with a time interval of a few seconds, which in particular energy can be saved in a standby mode. If a user inadvertently shifts or even deliberately displaces a cooking pot during cooking, either a corresponding shift in the heating zone must be made or a suboptimal adjustment of the heating zone to the cookware element must be accepted.

In practice, however, it is difficult to distinguish between the intentional or unintentional shifting of a cooking utensil element and the removal of a cookware element from an initial position and the setting up of another cooking utensil element at a second position. According to the prior art, displacements of a cooking utensil element are therefore not reliable in matrix hobs detected so that the user must make the settings made for the heating zone in the initial position of the cookware element operating parameters in the end position of the cookware element again.

For example, from the DE 101 56 77 A1 is a method for operating a classic hob with fixed hotplates known, according to which adjustment data of a hotplate or heating zone can be transferred to another hotplate of the same cooking appliance. However, the transfer is not fully automatic in this hob, but is initiated by the operation of a switching element by a user.

The invention is in particular the object of providing a working method for operating a hob with freely definable heating zones, which has an improved ease of use.

The object is achieved by a method according to claim 1 and by a hob according to claim 11. Advantageous embodiments and modifications of the invention will become apparent from the dependent claims.

The invention is particularly based on a method for operating a hob with a plurality of heating elements. The method comprises detecting a cooking utensil element by a detection arrangement, forming a heating zone adapted to the detected cookware element from one or more heating elements, and setting at least one operating parameter of a heating zone by means of a user interface.

In particular, it is proposed that an operation involving the removal of the cooking utensil element from an initial position and the subsequent placement of the cooking utensil element in an end position is detected by the detection arrangement. It is essential that the control unit with the aid of the detection arrangement identifies the process as a whole and as a unit and does not interpret the process of removing the cooking utensil element and the process of setting up the cooking utensil element as two separate processes. The method therefore further comprises associating the operation with one of at least two cases by the control unit.

The process is interpreted in a first case as a movement of the same cooking utensil element from the initial position to the end position. In other cases, the control unit automatically recognizes that it is not about moving the same cooking utensil element, but removing a cooking utensil and setting up a new cookware element. At least in the first case of the displacement of the same cookware element, the control unit moves the heating zone from the region of the initial position into the region of the end position. For this purpose, the heating zone new heating elements are assigned and at least a portion of the heating zone originally assigned heating elements is removed or deactivated. At least in the first case, which relates to a displacement of the same cookware element, the originally set operating parameters for the displaced heating zone are taken over by the control unit. As a result, the ease of use can be significantly improved because a readjustment of the operating parameters can be omitted.

In one development of the invention, it is proposed that the assignment of the process to one of the cases takes place on the basis of at least one parameter which can be set by the user via the user interface. In particular, the control unit can determine a parameter for the process, compare this parameter with the parameter and perform the assignment or case distinction depending on the result of this comparison.

The control unit may determine suitable parameters, for example, if it determines a spatial distance between the starting position and the end position of the process. This distance can be used when assigning the operation to the different cases. Shifts by comparatively short distances are often unintentional, so that the adoption of the operating parameters of the heating zone corresponds to the user's request.

Further, the control unit can also determine a time interval between the removal of the cooking utensil element from the initial position and the setting up of the cookware element in the end position and perform the assignment of the process depending on the time interval. A large time interval speaks for the desire of the user to interrupt the original cooking process and to start a new cooking process, while moving or switching the cooking utensil element in a short time interval usually reflects the desire of the user not to interrupt the cooking process as possible. The time in which the converted or displaced cookware element remains unheated can be shortened by the automatic adoption of the operating parameters.

The case of a displacement of the same cooking utensil element can be easily distinguished from the setting up of another cooking utensil element by the control unit, when the control unit determines a size and / or shape of the cooking utensil element removed from the initial position with a size and / or shape of the cooking utensil element placed on the end position compares. If the differences in size and shape are within a measurement accuracy of the detection assembly, it is likely to be the same cookware element, while otherwise being a different cookware element, so that adoption of the operating parameters for the new cookware element is unlikely to be desired.

Another feature that can be used to identify the cooking utensil element is the material properties of the cookware element. These can be measured by the detection arrangement and used by the control unit to identify the cookware element.

According to a particularly advantageous embodiment of the invention it is proposed that in at least one case the user can select by an input in the user interface, whether the set operating parameters or the set operating parameters for the relocated heating zone to be adopted or not. The intervention of the user in cases of doubt, a misinterpretation of the process, which could upset the user, can be avoided.

It is also proposed that the control unit assign the process to one of at least three cases. In a first case, a shift of the same cookware element is clearly identified and the set operating parameters are automatically adopted for the displaced heating zone. In a second case, the assignment or classification of the process is unclear and the operating parameters or the operating parameters are only accepted for the relocated heating zone if the user by a corresponding input confirmed. The user may be prompted by a plain text display on the user interface to make such an entry. In a third case, the user's desire to create a new heating zone is unambiguous, and the operating parameters for the displaced heating zone are set to a default value, such as power level 0.

In addition to the above-mentioned parameters, which allow the process to be assigned to the different cases, the control unit can detect a speed of movement of the cookware element from the initial position to the end position and determine the temperature of the cookware element. Both parameters can be used to classify the process and / or to identify the cookware element.

The operating parameters of the heating zone taken over in accordance with the invention can in particular comprise a heating power or power level of the heating zone and timer settings, for example a remaining running time. If more complex operating programs occur on the heating zone, operating programs interrupted by the movement of the cooking utensil element can continue on the displaced heating zone.

Another aspect relates to a hob with a control unit that performs the inventive method. The cooktop comprises a plurality of heating elements, a detection arrangement, a control unit and a user interface.

Further and characteristic features of the invention will become apparent from the description of the drawings. In the drawing, an embodiment of the invention is shown. The drawing, the description and the claims contain numerous features in combination. The person skilled in the art will expediently also consider the features individually and combine them into meaningful further combinations.

Fig. 1

ein Kochfeld mit einer Vielzahl von Heizelementen, einer Steuerein- heit und einer Benutzerschnittstelle,

Fig. 2

eine schematische Darstellung eines Vorgangs, der das Entfernen eines Kochgeschirrelements aus einer Anfangsposition und das an- schließende Aufstellen des Kochgeschirrelements in einer Endposi- tion umfasst, und

Fig. 3

eine schematische Darstellung der Zuordnung des Vorgangs aus Fig. 2 zu verschiedenen Fällen.

Show it:

Fig. 1

a hob with a plurality of heating elements, a control unit and a user interface,

Fig. 2

a schematic representation of an operation, which includes the removal of a cooking utensil element from an initial position and the subsequent installation of the cooking utensil element in an end position, and

Fig. 3

a schematic representation of the assignment of the process Fig. 2 to different cases.

Fig. 1 shows an induction hob with a plurality of heating elements designed as inductors 10. The inductors 10 are arranged in a uniform grid, identical in construction and can be operated by a control unit 18 substantially independently of each other. The control unit 18 is a universally programmable arithmetic unit that generates control signals for operating one or more power electronics assemblies 28. The power electronics assemblies 28 include a plurality of inverters 40, a filter 42 and a rectifier 44. A switching arrangement 48 connects the inverters 40 to different inductors 10. The inverters 40 generate a high frequency heating current that flows through the inductors 10 and generates a high frequency magnetic field. The magnetic field creates eddy currents in a bottom of a cooking utensil element 12 placed on the hob, which heat the cookware element 12. The heating power generated by the inductors 10 may be adjusted by varying a frequency and / or amplitude of the heating current generated by the inverters 40.

The control unit 18 uses the inductors 10 as a detection arrangement 14 for detecting the cookware elements 12 placed on the hob. For this purpose, the control unit 18 measures the influence of the cookware elements 12 on the inductance of the inductors 10 and of the inductors 10 and the bottom of the cookware element 12 existing overall system. Furthermore, the electrical losses in the bottom of the cookware element 12 lead to a frequency-dependent resistance or loss angle in the inductors 10. These loss angles can be used in addition to the detection of the cookware element 12 or for measuring material properties of its ferromagnetic ground.

Depending on these measured variables, the control unit 18 can determine, in particular, a degree of overlap between the bottom of the cookware element 12 and each of the inductors 10 and the position, size and shape of the bottom from these measured variables determine the cooking utensil element 12. Depending on these data, the control unit 18 forms for each cookware element 12 a heating zone 16 which is adapted in size, shape and position to the size, shape and position of the detected cookware element 12. The control unit 18 combines those inductors 10, which are covered by the bottom of the cooking utensil element 12 for more than a predetermined proportion, to the heating zone 16 which is assigned to the relevant cookware element 12.

At a front edge of the hob, this comprises a user interface 26, on which the control unit 18 visualizes the heating zones 16 adapted to the detected cookware elements 12. The user may set a power level and other operating parameters, such as a timer run time or a time for automatically turning off the heating zone 16, to each heating zone 16 via the user interface 26.

Fig. 2 schematically shows a process in which the cooking utensil element 12 shown as a circle is removed from an initial position 20 and then placed in an end position 22. The detection arrangement 14 detects the position, size and shape of the cookware element 12 in regular cycles, in particular with cycle times of less than one second. The measurement data are stored so that a change in position is detected directly by comparing the earlier measurement data with the current measurement data can be.

If a change in the measurement data of the detection arrangement 14 is detected that is greater than a threshold determined by the measurement accuracy of the detection arrangement 14, a timer or a time detection algorithm of the control unit 18 begins to run.

FIG. 3 FIG. 10 is a flow chart of a case discrimination algorithm for classifying these operations. FIG. If the setting up of the cookware element 12 in the end position 22 is detected within a predetermined time of about 10 seconds, the in Fig. 3 schematically illustrated algorithm which serves to assign this process to one of three cases. This allocation algorithm is implemented in the control unit 18 as software.

In a step 30, the control unit 18 determines a distance between the centers of the initial position 20 and the end position 22 and stores this distance as a distance value d. In a step 32, the control unit 18 determines a time difference between the removal of the cooking utensil element 12 from the initial position 20 and the setting up of the cookware element 12 in the end position 22 and stores the thus determined time interval as a value t. In a step 34, the control unit 18 determines a diameter of the cookware element removed from the initial position 20 and the cookware element placed on the end position 22 and forms the difference between these two diameters. This difference is stored as value s.

In a step 36, three cases are distinguished. In a first case, both the value d is smaller than a first threshold value d1 and the value t is smaller than a threshold value t1 and the value s is smaller than a threshold value s1. When this occurs, in a step 38, the heating zone 16 is moved to the area of the end position 22 and the operating parameters set for the heating zone 16 in their original position are taken over by the control unit 16 for the displaced heating zone 16.

If this is not the case, the control unit checks in a step 37 whether the second or the third case occurs. In the third case, which occurs when both the value d is greater than a threshold d2 and the value t is greater than a threshold t2 and the value s is greater than a threshold s2, the probability is very high the cookware element detected in the end position 22 does not act around the cookware element 12 remote from the initial position 20 and that the user wishes to start a new cooking process. All operating parameters of the displaced heating zone 16 are then set to zero. In particular, the power level is set to zero and all timer functions are disabled. The threshold values d2, t2 and s2 are each greater than the threshold values d1, t1 and s1.

In a second case, which occurs when neither the first nor the third case occurs, ie in particular when at least one of the values d, t, s lies between the two relevant threshold values d1, d2 or t1, t2 or s1, s2 , on a display of the user interface 26, the user is prompted to decide whether to accept the user setting from the old heating zone 16 to the displaced heating zone 16 should or should not be. If no user input occurs after a predetermined time, the operating parameters of the heating zone 16 are set to zero.

The user can change the threshold values d1, d2, s1, s2, t1, t2 via the user interface 26 in order to adapt them to his needs. In a particularly advantageous embodiment, the user can only change one parameter that describes the sensitivity of the system. The controller 18 may then determine the various thresholds depending on the parameter set by the user. In addition to the values d, t, s, in particularly advantageous embodiments of the invention the detection arrangement 14 or the control unit 18 can also detect the temperature of the cookware element 12. If the temperature of the cooking utensil remote from the initial position 20 is very different from the temperature of the cooking utensil erected on the end position 22, then in all likelihood it will not be the same cookware element. The identification of the cookware element 12 can also be improved by measuring the material properties of the cookware element 12.

Further, the control unit 18 may also determine the speed of a shift operation of the cookware element 12, for example by dividing the value d by the value t. If the detection takes place at a high measuring frequency, of course, further points of a trajectory of the cookware element 12 can be determined, which facilitates the distinction of a displacement of the cookware element from the setting up of another cooking utensil element.

reference numeral

10

heating element

12

Cookware element

14

detection device

16

heating zone

18

control unit

20

starting position

22

end position

26

User interface

28

Power electronics module

30

step

32

step

34

step

36

step

37

step

38

step

40

inverter

42

filter

44

rectifier

48

switching arrangement

Claims (11)

1. Method for operating a cooker hob with a plurality of heating elements (10) comprising the steps:

   - detecting a cooking vessel element (12) by a detection arrangement (14),

   - forming a heating zone (16), which is adapted to the detected cooking vessel element (12), from one or more heating elements (10) by a control unit (18) and

   - setting at least one operating parameter of a heating zone (16) by means of a user interface (26),

   characterised by the steps:

   - detecting a process comprising removal of the cooking vessel element (12) from a starting position (20) and subsequent placing of a cooking vessel element (12) in an end position (22),

   - assigning the process to one of at least two cases by the control unit (18), wherein the process at least in a first case is interpreted as a movement of the same cooking vessel element (12) from the starting position (20) to the end position (22),

   - shifting the heating zone (16) into the region of the end position (22) in connection with the process at least in the first case and

   - taking over the at least one set operating parameter for the shifted heating zone (16) by the control unit (18) at least in the first case.
2. Method according to claim 1, characterised in that the assignment of the process to one of the cases is carried out on the basis of at least one parameter settable by a user.
3. Method according to any one of the preceding claims, characterised in that the control unit (18) determines a physical spacing (d) between the starting position (20) and the end position (22) of the process, wherein the assignment of the process takes place in dependence on the spacing (d).
4. Method according to any one of the preceding claims, characterised in that the control unit (18) determines a spacing (t) in time between the removal of the cooking vessel element (12) from the starting position (20) and setting up of the cooking vessel element (12) in the end position (22), wherein the assignment of the process takes place in dependence on the spacing (t) in time.
5. Method according to any one of the preceding claims, characterised in that the control unit (18) compares a magnitude of the cooking vessel element (12) removed from the starting position (20) with a magnitude of the cooking vessel element (12) set up at the end position (22), wherein the assignment of the process is carried out in dependence on the result of this comparison.
6. Method according to any one of the preceding claims, characterised by measurement of material characteristics of the cooking vessel element (12) by the detection arrangement (14) and identification of the cooking vessel element (12) in dependence on the material characteristics of the cooking vessel element (12).
7. Method according to any one of the preceding claims, characterised in that in at least one case the user selects, by input into the user interface (26), whether the at least one set operating parameter is to be taken over for the shifted heating zone (16).
8. Method according to any one of the preceding claims, characterised in that the control unit (18) assigns the process to one of at least three cases, wherein

   - in a first case the at least one set operating parameter is automatically taken over for the shifted heating zone (16),

   - in a second case the at least one set operating parameter is taken over for the shifted heating zone (16) only if the user confirms this by a corresponding input and

   - in a third case the at least one set operating parameter is set to a preset value.
9. Method according to any one of the preceding claims, characterised in that the control unit (18) detects a speed of movement of the cooking vessel element (12) from the starting position (20) to the end position (22) and assigns the process to a case in dependence on the speed.
10. Method according to any one of the preceding claims, characterised by measuring a temperature of the cooking vessel element (12) by the detection arrangement (14) and identifying the cooling vessel element (12) in dependence on the temperature of the cooking vessel element (12).
11. Cooker hob with a plurality of heating elements (10), comprising:

    - a detection arrangement (14) for detecting a cooking vessel element (12),

    - a control unit (18) designed for the purpose of forming a heating zone (16), which is adapted to the cooking vessel element (12), from one or more heating elements (10) and

    - a user interface (26) for setting at least one operating parameter of the heating zone (16),

    characterised in that the detection arrangement (14) and the control unit (18) are designed for the purpose of:

    - detecting a process which comprises the removal of the cooking vessel element (12) from a starting position (20) and subsequent setting up of a cooking vessel element (12) at an end position (22),

    - assigning the process to one of at least two cases, wherein the control unit (18) interprets the process at least in a first case as a movement of the same cooking vessel element (12) from the starting position (20) to the end position (22),

    - shifting the heating zone (16) at least in the first case into the region of the end position (22) and

    - at least in the first case taking over the at least one set operating parameter for the shifted heating zone (16).

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