METHOD FOR CONTROLLING A COOKING APPLIANCE USING AN EXTERNAL CONTROL UNIT, COOKING APPLIANCE AND SYSTEM

Abstract

In a method for controlling a cooking appliance having a heating device and an internal cooking appliance controller by means of an external control unit connected to a temperature sensor, a first step involves a plausibility check on the control commands and/or on the current operating state of the cooking appliance being performed for a temperature of a cooking vessel that has been put on. Differences for the plausibility check result in a release of power being reduced as a safety measure. A heating device controlled by the external control unit then has its power level and/or heating time period limited as the actual power and/or actual heating period when the heating device is actuated.

Claims

1. Method for controlling a cooking appliance using an external control unit, wherein: said cooking appliance has at least one heating device and an internal cooking appliance controller, said external control unit is arranged outside said cooking appliance, said external control unit is designed to give control commands to said cooking appliance controller to control at least said one heating device, said internal cooking appliance controller is designed for actuating said heating device and for storing a determined state of said cooking appliance, of the heating device or of said cooking vessel, wherein a state of said cooking appliance, of said heating device or of a cooking vessel thereon is determined by said cooking appliance controller, said state being observed or monitored during operation of said cooking appliance, wherein the following steps are performed: in one step, a plausibility check on said control commands or on said current operating state of said cooking appliance is performed, wherein said plausibility check involves said determined state being compared with other information pertaining to a state of said cooking appliance, of said heating device and/or of said cooking vessel in order to obtain a possible difference, wherein a difference below a limit value results in operation of said cooking appliance continuing and a difference above a limit value results in operation of said cooking appliance being limited, in one step, a control command of said external control unit for desired power level or desired heating period is detected by said cooking appliance controller, said step being able to be effected before or after said other aforementioned step, and in an event of said difference being below said limit value, a subsequent step involves a power level or heating period accepted by said cooking appliance controller, as an implementation of said control command for power level or for heating period for said at least one heating device controlled by said external control unit, being directly adopted as an actual power level and/or as an actual heating period being then used to actuate said heating device, in an event of said difference being above said limit value, said cooking appliance controller, in a subsequent step, when implementing said control command for said at least one heating device controlled by said external control unit, reduces a power level or heating period provided by said external control unit as said actual power level or as said actual heating period being then used to actuate said heating device.

2. Method according to claim 1, wherein a preceding step involves said external control unit being assigned to said cooking appliance or to said heating device.

3. Method according to claim 2, wherein said preceding step involves said external control unit being assigned to said cooking appliance or said heating device together with activation or confirmation by a user at said cooking appliance in order to permit external control of a cooking process using said external control unit.

4. Method according to claim 1, wherein at least one sensor for determining a state of said cooking appliance, of said heating device or of said cooking vessel is provided, wherein said internal cooking appliance controller is designed for actuating said heating device and for storing a state of said cooking appliance, of said heating device or of said cooking vessel on a basis of said information of said sensor or said control commands of said external control unit, said at least one sensor being polled and said result of said poll being used in said cooking appliance controller.

5. Method according to claim 1, wherein a temperature of said cooking vessel is used for said plausibility check and a limit value for a temperature difference is 50 K.

6. Method according to claim 1, wherein said cooking appliance controller detects a state of said cooking appliance, of said heating device or of said cooking vessel by using at least one piece of information of a group of: released actual power level to said heating device, assumed, measured or input thermal mass of said cooking vessel along with content.

7. Method according to claim 1, wherein said external control unit gives control commands to said cooking appliance controller periodically or at self-determined times.

8. Method according to claim 7, wherein said control commands include power grades, a power level or a power density, a power density relating either to a size of said heating device or to a size of said cooking vessel.

9. Method according to claim 7, wherein said external control unit gives control commands to said cooking appliance controller in an event of a change in a power requirement for said heating device.

10. Method according to claim 1, wherein if no control command comes from said external control unit for a time longer than a limit time, a fresh plausibility check on a current operating state of said cooking appliance is performed.

11. Method according to claim 1, wherein energy packets are released by said cooking appliance controller with stipulated energy, a power level or a heating period being determined with reciprocal influencing on a basis of said stipulated energy or size of said released energy packet.

12. Method according to claim 11, wherein consumption of one said energy packet by said cooking appliance controller is followed by a new energy packet of said same level being released only if a difference after performance of a plausibility check is below said limit value.

13. Method according to claim 11, wherein consumption of one said energy packet without new release of a new energy packet is followed by said heating device being shut down or now being operated only at a power level of no more than 2.2 W/cm.sup.2.

14. Method according to claim 1, wherein if a plausibility check is not passed and a difference is above said limit value, said cooking appliance is either switched off or a power level is lowered to a level being permanently uncritical for an operation of said heating device.

15. Method according to claim 4, wherein a dynamic range of a sensor according to claim 4 allows a check to be performed to determine how a signal of said sensor changes on a basis of a supplied power to said heating device, a dynamic range ascertained in said manner being taken as a basis for determining a maximum permissible power level that said heating device is permitted to supply to a cooking vessel without there being a risk of overheating.

16. Method according to claim 15, wherein a high dynamic range with a quickly rising signal of said sensor results in said cooking appliance controller permitting a high power level of from 3.6 W/cm.sup.2 to 10 W/cm.sup.2.

17. Method according to claim 15, wherein a low dynamic range with a slowing rising signal of said sensor results in said cooking appliance controller permitting a low power level of from 0% to 50% of a maximum power level or up to 3.6 W/cm.sup.2.

18. Method according to claim 15, wherein a further step, as a checking step, involves a trend in a power level that differs from a preset of said external control unit being taken with said heating device so as to cause a reactive response by a regulator in said cooking appliance controller, a time before said reactive response ensues being taken as a basis for estimating a dynamic range of a control loop, with a low dynamic range if a time before said reactive response ensues is long and with a high dynamic range if said time before said reactive response ensues is short.

19. Method according to claim 18, wherein said further step, as a checking step, involves a trend in said power level differring from a preset of said external controller by 20% to 200% of said prescribed power level being taken with said heating device.

20. Method according to claim 18, wherein if there is no reactive response within a predefined time, a safety function is caused and a power level is reduced or terminated by said cooking appliance controller or other additional safety measures are taken.

21. Method according to claim 1, wherein if there are no signals from sensors of said external control unit, a maximum permissible power level is limited by said cooking appliance controller on a basis of a change of state of detection means directly connected to said cooking appliance controller or of sensors or of sensors firmly arranged on said cooking vessel.

22. Method according to claim 1, wherein said external control unit is a remote control connected to said cooking appliance controller by means of a radio link, wherein said external control unit has a temperature sensor as remote control and is itself arranged on a cooking utensil or is integrated in a cooking utensil, said external control unit undertaking a temperature regulation for said cooking utensil and, to said end, prescribing a power regulation for said heating device of said cooking utensil for said cooking appliance controller.

23. Method according to claim 1, wherein said external control unit is a remote control connected to said cooking appliance controller by means of a radio link, wherein said external control unit is wirelessly connected to a temperature sensor by means of a radio link, said temperature sensor being arranged on a cooking utensil or being integrated in a cooking utensil.

24. Method according to claim 1, wherein said external control unit is a mobile terminal such as a smartphone or a tablet computer, said mobile terminal performing a temperature regulation directly or via an app running thereon to prescribe a heating power for said heating device by means of control commands.

25. Cooking appliance having at least one heating device and an internal cooking appliance controller, wherein said cooking appliance controller is designed to carry out a method according to claim 1.

26. System having a cooking appliance according to claim 25 and an external control unit, wherein said external control unit is designed for arrangement outside said cooking appliance and is designed to give control commands to said cooking appliance controller for controlling at least said heating device.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)

[0045] Having thus described the invention in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein:

[0046] FIG. 1 shows a depiction of a system according to the invention with a hob as the cooking appliance according to the invention and a cellphone as the external control unit and with a temperature sensor in two possible positions.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

[0047] FIG. 1 shows a system 11 according to the invention that has a hob 13 as the cooking appliance according to the invention and a cellphone 25 as the external control unit. The hob 13 has an inherently standard design with a hot plate 14 and a housing 15 beneath it in which the functional units of the hob are arranged. A hob controller 17 is arranged therein, which is connected to an operator control device 20. The latter is depicted on the hob plate 14, even though it may and should be arranged beneath it in practice. The operator control device 20 has operator control elements and a display, as is known.

[0048] In addition, the hob controller 17 is connected to a radio module 18 or has such a radio module for communication with the cellphone 25. The radio module 18 can use a radio standard that the cellphone has control over, for example WLAN, ZigBee, Bluetooth or BLE. All four suffice for the ranges and distances usually desired or needed in practice. Alternatively, if instead of the cellphone another external control unit is used, then another radio standard can be used. The radio module 18 may be arranged beneath the hob plate 14 in the housing 15, sometimes directly on the underside of the hob plate 14 for the most interference-free radio transmission possible. If the cooking appliance according to the invention is an oven, then a spit advantageously used therein could be connected as an external control unit with a temperature probe to an oven controller by means of a cable, since radioing from an oven muffle is difficult. The cable connection to the oven controller would then be consistent with the radio module 18 as the communication module for the controller, in particular a plug socket on an internal wall of the oven muffle.

[0049] The hob 13 has multiple heating devices 22 in the housing that are positioned on the underside of the hob plate 14. Advantageously, these are induction heating coils 22 in this case, but there may be any type of heating device, including radiant heating devices and gas or hybrid forms thereof. The induction heating coils 22 can be operated individually or can be operated in combination as one hot plate and at a common power grade or power density, in which case they operate exactly like a single heating device for the purposes of understanding the present invention.

[0050] The cellphone 25 can be used in a manner known per se to input information or presets by means of operator control elements 27. Information can be displayed to a user on a display 28. If the cellphone 25 is a smartphone, or alternatively a tablet computer, then it can have a known touchscreen, which combines operator control elements and displays. Instead of a cellphone or tablet computer, the external control unit may also be a specific remote control, either just with operator control elements or even with automatic programs stored therein.

[0051] A central induction heating coil 22 has a cooking vessel 30 put on it with a lid 31, which contains water 32 for a cooking process, in this case, by way of example, because a user wants to cook noodles. On the lid 31, there is a temperature probe 35 arranged in a first position, for example magnetically or by clamping. The temperature probe 35 ascertains the temperature at the saucepan lid, the temperature of the water 31 being able to be determined therefrom, for example by a temperature sensor therein that is resiliently pressed against the lid 31 and has direct contact. As an alternative mounting location, the second positiondepicted by dashed linesat the bottom right on the side of the cooking vessel 30 could be used, with the advantage that here the temperature of the water 32 itself can be determined relatively directly through the wall of the cooking vessel 30. There is also good freedom from emissions for the radio connection at this location, albeit not quite as good as at the top on the lid 31. As yet a further alternative, a temperature probe 35 could also have a protruding temperature sensor that is arranged at the front on a short flexible cable, for example. This protruding flexible temperature sensor can then protrude into the cooking vessel 30 from above and be suspended in the water 32 in order to measure the water temperature directly and with maximum freedom from distortion. The temperature probe 35 could also generally have multiple temperature sensors for a distributed and better measurement. Finally, it is also possible to use a standard temperature sensor on the top of the induction heating coil. Although this temperature sensor primarily has a protective function against overheating of the induction heating coil itself or of the hob plate 14 made of glass ceramic, it can also be used for this purpose, at least for an aforementioned plausibility check.

[0052] The temperature probe 35 has a radio connection or is designed for one to an integrated radio module, not depicted, wherein a radio standard may be consistent with the radio module 18, but above all needs to be suitable for the cellphone 25. The supply of power is advantageously provided by means of an installed storage battery. The temperature probe 35 just has at least one temperature sensor, not depicted, which is advantageously in contact with the cooking vessel or the lid 31. The temperature probe 35 regularly sends signals containing the temperature information to the cellphone 25 via a radio connection. The cellphone 25 then uses this temperature information to perform an automatic program, for example, as mentioned above, for cooking noodles. This automatic program can run on an app on the cellphone 25 that also permits user inputs. These may be different, for example as a main item a selection for cooking noodles. As a subitem, a cooking time for the noodles can then be input, for example 10 min. Alternatively, this could also be detected by a camera of the cellphone 25 by means of character recognition or as more easily readable preparation information by means of QR code or the like.

[0053] After the automatic program starts, the temperature probe 35 can be used to detect the temperature of the water 31. The automatic program first of all sends control commands to the cooking appliance controller 17 via the radio module 18, said commands being implemented by the cooking appliance controller 17 as a power preset for the induction heating coils 22. To quickly boil water, the power preset will usually be very high so that the water 32 boils quickly. However, the plausibility check according to the invention now also begins. In this case, there may be provision for the cooking appliance controller 17 to detect and store the total energy passed to the induction heating coil 22. This energy is then compared with the temperature information of the temperature probe 35, which the cellphone 25 transmits to the controller for this purpose. If the measured temperature is plausible in view of the detected energy or appropriate thereto, then operation of the hob can continue without alteration. This plausibility check is performed continually, for example every 10 sec. or every 30 sec. This may be dependent on how high the desired power is, that is to say more frequently for a high desired power.

[0054] As an additional safety measure, it is possible to check whether the dynamic range of the temperature probe along with the remainder of the system is plausible or indicates that the system 11 is operating correctly. By way of example, this can be accomplished by reducing the power or briefly shutting down the induction heating coil 22 completely, for example for 10 sec. or 20 sec. The induction heating coil is then switched on again at full power. In the brief interim, the cooking vessel 30 and above all the water 32 have cooled somewhat, perhaps by 5 K. After the induction heating coil 22 is switched on full power again in this way, the temperature of the water 32 will probably rise quickly to 100 C. The cooking appliance controller 17 thus knows that in this case the dynamic range of the system is quite high. Therefore, the cooking appliance controller 17 can release the full power for the induction heating coil 22, since the control loop is closed and above all is fairly quick. If the result were a low dynamic range or a more sluggish response, then the cooking appliance controller 17 would release only a reduced power and not the full power.

[0055] The plausibility check is then repeated continually, in particular regularly. It can be performed every 10 sec. or perhaps every 30 sec. A shorter interval is regarded as not necessary, and an even longer interval would possibly be too risky.

[0056] One option for operation would in fact also be if the cooking appliance controller 17 only releases energy packets, that is to say just a release of power with a time and/or level limit. This could be appropriate above all if the plausibility check had not been passed. However, these energy packets are then proportioned such that it would probably take longer for the noodles to cook than at maximum power. The cooking appliance controller 17 can in this case also control the energy packets such that after one is used up the next is immediately provided so long as a critical situation is not discovered. Only for an unlimited and unmonitored release of power is it then not sufficient.

[0057] When the temperature probe 35 has detected that the boiling point of the water 32 has been reached, it passes this information to the cooking appliance controller 17 via the automatic program. One alternative is that the latter then generates a signal to the user or the cellphone 25 itself The user can then put the noodles into the boiling water. Another alternative is that the temperature probe 35 detects this from a distinct drop in temperature, or the user enters it into the cellphone 25. The automatic program then adjusts the temperature of the water 32, normally by reducing the power preset after one minute, to just below 100 C. on the basis of the temperature information. The user then does not need to be present for this, since the system is automatic, of course, and he also knows when the noodles will have finished being cooked. At the end of this, the power is best turned off completely and a signal is delivered to the user again. In this case, the cellphone 25 operates as an automatic control unit, since an automatic program runs on it. Alternatively, it would be easily conceivable for it to operate as a manual control unit if a user can use the cellphone 25 and a remote control, too, to input explicit and direct operator control commands that can be given to the cooking appliance controller 17 as control commands. By way of example, this would be a direct power preset, for example with power grades. In principle, a direct power preset of this kind is consistent with an input as on the operator control device 20. The cellphone 25 can thus be operated either as an automatic control unit or as a manual control unit and may then be such a unit for the cooking appliance controller 17.

[0058] The safety of operator control using the cellphone 25 and the temperature probe 35 is ensured by the plausibility check according to the invention.