Patent Publication Number: US-2023152825-A1

Title: Cooktop appliance with adaptive closed-loop controls

Description:
FIELD OF THE INVENTION 
     The present subject matter relates generally to cooktop appliances, including cooktop appliances configured for precise temperature control. 
     BACKGROUND OF THE INVENTION 
     Cooktop appliances generally include heating elements for heating cooking utensils, such as pots, pans and griddles. A user can select a desired heating level, and operation of one or more of the heating elements is modified to match the desired heating level. For example, certain cooktop appliances include electric heating elements. During operation, the cooktop appliance operates the electric heating elements at a predetermined power output corresponding to a selected heating level. As another example, some cooktop appliances include gas burners as heating elements. During operation, the heat output of the gas burner is modulated by adjusting a position of a control valve coupled to the gas burner. 
     Some cooktop appliances are operable in a precision mode, which generally uses a closed-loop control algorithm to vary the output of the heating element in response to the desired heating level and a measured temperature, e.g., of or at the cooking utensil. Typical closed-loop control algorithms are attuned to a fixed end point and may not perform efficiently or produce desired results when the set point or end point varies, e.g., when the desired heating level is changed during the precision mode. 
     Accordingly, a cooktop appliance with features for improved precision temperature control, such as precision temperature control that is adaptive to changes in the target temperature, would be useful. 
     BRIEF DESCRIPTION OF THE INVENTION 
     Aspects and advantages of the invention will be set forth in part in the following description, or may be apparent from the description, or may be learned through practice of the invention. 
     In one example embodiment, a cooktop appliance includes a user interface, a heating element positioned at a cooking surface of the cooktop appliance, and a temperature sensor configured to measure a temperature at a utensil heated by the heating element. The cooktop appliance also includes a controller. The controller is configured for receiving a first user-determined set temperature from the user interface, receiving a precision mode initiation signal, and receiving a temperature measurement from the temperature sensor. The controller is also configured for determining a first set of parameters of a closed-loop algorithm for operation of the heating element corresponding to the mathematical difference between the first user-determined set temperature and the temperature measurement. The controller is further configured for inputting the first user-determined set temperature and the temperature measurement into the closed-loop control algorithm, determining a first output of the closed-loop control algorithm using the first set of parameters, and adjusting operation of the heating element according to the first output of the closed-loop control algorithm. The controller is also configured for receiving a second user-determined set temperature from the user interface of the cooktop appliance after receiving the first user-determined set temperature. The second user-defined set temperature differs from the first user-defined set temperature. The controller is further configured for determining a second set of parameters of the closed-loop algorithm for operation of the heating element based on the second user-determined set temperature, determining a second output of the closed-loop control algorithm using the second set of parameters, and adjusting operation of the heating element according to the second output of the closed-loop control algorithm. 
     In another example embodiment, a method of operating a cooktop appliance is provided. The method includes receiving a first user-determined set temperature from a user interface of the cooktop appliance, receiving a precision mode initiation signal, and receiving a temperature measurement from a temperature sensor configured to measure a temperature at a utensil heated by a heating element positioned at a cooking surface of the cooktop appliance. The method also includes determining a first set of parameters of a closed-loop algorithm for operation of the heating element corresponding to the mathematical difference between the first user-determined set temperature and the temperature measurement, inputting the first user-determined set temperature and the temperature measurement into the closed-loop control algorithm, determining a first output of the closed-loop control algorithm using the first set of parameters, and adjusting operation of the heating element according to the first output of the closed-loop control algorithm. The method also includes receiving a second user-determined set temperature from the user interface of the cooktop appliance after receiving the first user-determined set temperature. The second user-defined set temperature differs from the first user-defined set temperature. The method further includes determining a second set of parameters of the closed-loop algorithm for operation of the heating element based on the second user-determined set temperature, determining a second output of the closed-loop control algorithm using the second set of parameters, and adjusting operation of the heating element according to the second output of the closed-loop control algorithm. 
     These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures. 
         FIG.  1    provides a front, perspective view of a range appliance having a cooktop according to one or more example embodiments of the present subject matter. 
         FIG.  2    provides a top, plan view of the example appliance of  FIG.  1   . 
         FIG.  3    is a schematic top view of an exemplary cooktop according to one or more example embodiments of the present subject matter which may be incorporated into a range appliance such as the range appliance of  FIG.  1   . 
         FIG.  4    provides a schematic diagram of a control system as may be used with the exemplary cooktop appliance of  FIG.  3   . 
         FIGS.  5  and  6    provide a flow chart illustrating an exemplary method of operating a cooktop appliance according to one or more example embodiments of the present subject matter. 
     
    
    
     DETAILED DESCRIPTION 
     Reference now will be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents. 
       FIG.  1    provides a front, perspective view of a cooktop appliance  100  as may be employed with the present subject matter.  FIG.  2    provides a top, plan view of cooktop appliance  100 . As illustrated in  FIGS.  1  and  2   , the example cooktop appliance  100  includes an insulated cabinet  110 . Cabinet  110  defines an upper cooking chamber  120  and a lower cooking chamber  122 . Thus, this particular exemplary cooktop appliance  100  is generally referred to as a double oven range appliance. As will be understood by those skilled in the art, range appliance  100  is provided by way of example only, and the present subject matter may be used in any suitable cooktop appliance, e.g., a single oven range appliance or a standalone cooktop appliance. In other exemplary embodiments of the present disclosure, the cooktop appliance may include a single cooking chamber, or no cooking chamber at all, such as a standalone cooktop appliance, e.g., which may be built in to a countertop. Thus, the example embodiment shown in  FIG.  1    is not intended to limit the present subject matter to any particular cooking chamber configuration or arrangement (or even the presence of a cooking chamber at all, e.g., as in the case of a standalone cooktop appliance). 
     Upper and lower cooking chambers  120  and  122  are configured for the receipt of one or more food items to be cooked. Cooktop appliance  100  includes an upper door  124  and a lower door  126  rotatably attached to cabinet  110  in order to permit selective access to upper cooking chamber  120  and lower cooking chamber  122 , respectively. Handles  128  are mounted to upper and lower doors  124  and  126  to assist a user with opening and closing doors  124  and  126  in order to access cooking chambers  120  and  122 . As an example, a user can pull on handle  128  mounted to upper door  124  to open or close upper door  124  and access upper cooking chamber  120 . Glass window panes  130  provide for viewing the contents of upper and lower cooking chambers  120  and  122  when doors  124  and  126  are closed and also assist with insulating upper and lower cooking chambers  120  and  122 . Heating elements (not shown), such as electric resistance heating elements, gas burners, microwave heating elements, halogen heating elements, or suitable combinations thereof, are positioned within upper cooking chamber  120  and lower cooking chamber  122  for heating upper cooking chamber  120  and lower cooking chamber  122 . 
     Cooktop appliance  100  also includes a cooktop  140 . Cooktop  140  is positioned at or adjacent to a top portion of cabinet  110 . Thus, cooktop  140  is positioned above upper and lower cooking chambers  120  and  122 . Cooktop  140  includes a top panel  142 . By way of example, top panel  142  may be constructed of glass, ceramics, enameled steel, and combinations thereof. 
     For cooktop appliance  100 , a utensil  18  (see, e.g.,  FIGS.  3  and  4   ) holding food and/or cooking liquids (e.g., oil, water, etc.) may be placed onto grates  152  at a location of any of burner assemblies  144 ,  146 ,  148 ,  150 . Burner assemblies  144 ,  146 ,  148 ,  150  provide thermal energy to cooking utensils on grates  152 . As shown in  FIG.  2   , burner assemblies  144 ,  146 ,  148 ,  150  can be configured in various sizes so as to provide e.g., for the receipt of cooking utensils (i.e., pots, pans, etc.) of various sizes and configurations and to provide different heat inputs for such cooking utensils. Grates  152  are supported on a cooking surface, e.g., top surface  158  of top panel  142 . Range appliance  100  also includes a griddle burner  160  positioned at a middle portion of top panel  142 , as may be seen in  FIG.  2   . A griddle may be positioned on grates  152  and heated with griddle burner  160 . 
     A user interface panel  154  is located within convenient reach of a user of the range appliance  100 . For this example embodiment, range appliance  100  also includes knobs  156  that are each associated with one of burner assemblies  144 ,  146 ,  148 ,  150  and griddle burner  160 . Knobs  156  allow the user to activate each burner assembly and determine the amount of heat input provided by each burner assembly  144 ,  146 ,  148 ,  150  and griddle burner  160  to a cooking utensil located thereon. The user interface panel  154  may also include one or more inputs  157 , such as buttons or a touch pad, for selecting or adjusting operation of the range appliance  100 , such as for selecting or initiating a precision cooking mode, as will be described in more detail below. User interface panel  154  may also be provided with one or more graphical display devices  155  that deliver certain information to the user such as e.g., whether a particular burner assembly is activated and/or the temperature at which the burner assembly is set. 
     Although shown with knobs  156 , it should be understood that knobs  156  and the configuration of range appliance  100  shown in  FIG.  1    is provided by way of example only. More specifically, range appliance  100  may include various input components, such as one or more of a variety of touch-type controls, electrical, mechanical or electro-mechanical input devices including rotary dials, push buttons, and touch pads. The user interface panel  154  may include other display components, such as a digital or analog display device  155 , designed to provide operational feedback to a user. 
       FIG.  3    is a schematic view of certain components of cooktop appliance  100 . In particular, as shown in  FIG.  3   , cooktop appliance  100  includes a plurality of heating elements  16 , which may be gas burners, e.g., as in the exemplary embodiments illustrated in  FIGS.  1  and  2    and described above, or may be electric heating elements, such as induction heating elements or resistance heating elements. 
     Referring now to  FIG.  3   , a top, schematic view of a cooktop, which may be, e.g., the cooktop  140  of  FIG.  1   , is provided. As stated, the cooking surface  158  of the cooktop  140  for the embodiments depicted includes five heating elements  16  spaced along the cooking surface  158 . The heating elements  16  may be gas burners, e.g., as illustrated in  FIGS.  1  and  2   , or may be electric heating elements such as resistance heating elements or induction heating elements, etc. A cooking utensil  18 , also depicted schematically, is positioned on a first heating element  16  of the plurality of heating elements  16 . For the embodiment depicted, a cookware temperature sensor  28  and a food temperature sensor  30  are also associated with the cooking utensil  18 . 
     In some example embodiments, the cookware temperature sensor  28  may be in contact with, attached to, or integrated into the cooking utensil  18  and configured to sense a temperature of, e.g., a bottom surface of the cooking utensil  18  or bottom wall of the cooking utensil  18 . For example, the cookware temperature sensor  28  may be embedded within the bottom wall of the cooking utensil  18  as illustrated in  FIG.  3   . Alternatively, however, the cookware temperature sensor  28  may be attached to or integrated within the cooking surface  14  of the cooktop appliance  12 . For example, the cookware temperature sensor  28  may be integrated into one or more of the heating elements  16 . With such an exemplary embodiment, the cookware temperature sensor  28  may be configured to physically contact the bottom surface of a bottom wall of the cooking utensil  18  when the cooking utensil  18  is placed on the heating element  16  into which the temperature sensor  28  is integrated. Alternatively, cookware temperature sensor  28  may be positioned proximate to the bottom surface or bottom wall of the cooking utensil  18  when the cooking utensil  18  is placed on the heating element  16 . 
     Additionally, the food temperature sensor  30  may be positioned at any suitable location to sense a temperature of one or more food items  32  (see  FIG.  4   ) positioned within the cooking utensil  18 . For example, the food temperature sensor  30  may be a probe type temperature sensor configured to be inserted into one or more food items  32 . Alternatively, however, the food temperature sensor  30  may be configured to determine a temperature of one or more food items positioned within the cooking utensil  18  in any other suitable manner. 
     In certain exemplary embodiments, one or both of the cookware temperature sensor  28  and the food temperature sensor  30  may utilize any suitable technology for sensing/determining a temperature of the cooking utensil  18  and/or food items  32  positioned in the cooking utensil  18 . The cookware temperature sensor  28  and the food temperature sensor  30  may measure a respective temperature by contact and/or non-contact methods. For example, one or both of the cookware temperature sensor  28  and the food temperature sensor  30  may utilize one or more thermocouples, thermistors, optical temperature sensors, infrared temperature sensors, resistance temperature detectors (RTD), etc. 
     As used herein, “temperature sensor” or the equivalent is intended to refer to any suitable type of temperature measuring system or device positioned at any suitable location for measuring the desired temperature. Thus, for example, temperature sensors  28  and  30  may each be any suitable type of temperature sensor, such as a thermistor, a thermocouple, a resistance temperature detector, a semiconductor-based integrated circuit temperature sensors, etc. In addition, temperature sensors  28  and  30  may be positioned at any suitable location to sense a temperature at a utensil  18  heated by the heating element  16 , and may output a signal, such as a voltage, to a controller (such as controller  52  and/or a controller onboard the sensor) that is proportional to and/or indicative of the temperature being measured. Although exemplary positioning of temperature sensors is described herein, it should be appreciated that appliance  100  may include any other suitable number, type, and position of temperature, humidity, and/or other sensors according to alternative embodiments. 
     Referring again to  FIGS.  3  and  4   , the cooktop appliance  100  additionally includes at least one receiver  34 . In the illustrated example of  FIG.  3   , the cooktop appliance  100  includes a plurality of receivers  34 , each receiver  34  associated with an individual heating element  16 . Each receiver  34  is configured to receive a signal from the food temperature sensor  30  indicative of a temperature of the one or more food items  32  positioned within the cooking utensil  18  and/or from the cookware temperature sensor  28  indicative of a temperature of the cooking utensil  18  positioned on a respective heating element  16 . In other embodiments, a single receiver  34  may be provided and the single receiver  34  may be operatively connected to one or more of the sensors. In at least some exemplary embodiments, one or both of the cookware temperature sensor  28  and the food temperature sensor  30  may include wireless transmitting capabilities, or alternatively may be hard-wired to the receiver  34 , e.g., through a wired communications bus. 
       FIG.  4    provides a schematic view of a system for operating a cooktop appliance  100  in accordance with an exemplary embodiment of the present disclosure. Specifically,  FIG.  4    provides a schematic view of a heating element  16  of the exemplary cooktop appliance  12  of  FIGS.  1  and  2    and an exemplary control system  50 . 
     As stated, the cooktop appliance  100  includes a receiver  34  associated with one or more of the heating elements  16 , for example a plurality of receivers  34  each associated with a respective heating element  16 . For the embodiment depicted, each receiver  34  is positioned directly below a center portion of a respective heating element  16 . Moreover, for the embodiment depicted, each receiver  34  is configured as a wireless receiver  34  configured to receive one or more wireless signals. Specifically, for the exemplary control system  50  depicted, both of the cookware temperature sensor  28  and the food temperature sensor  30  are configured as wireless sensors in wireless communication with the wireless receiver  34  via a wireless communications network  54 . In certain exemplary embodiments, the wireless communications network  54  may be a wireless sensor network (such as a Bluetooth communication network), a wireless local area network (WLAN), a point-to point communication networks (such as radio frequency identification (RFID) networks, near field communications networks, etc.), a combination of two or more of the above communications networks, or any suitable wireless communications network or networks. 
     Referring still to  FIG.  4   , each receiver  34  associated with a respective heating element  16  is operably connected to a controller  52  of the control system  50 . The receivers  34  may be operably connected to the controller  52  via a wired communication bus (as shown), or alternatively through a wireless communication network similar to the exemplary wireless communication network  54  discussed above. The controller  52  may generally include a computing device  56  having one or more processor(s)  58  and associated memory device(s)  60 . The computing device  56  may be configured to perform a variety of computer-implemented functions to control the exemplary cooktop appliance  100 . The computing device  56  can include a general purpose computer or a special purpose computer, or any other suitable computing device. It should be appreciated, that as used herein, the processor  58  may refer to a controller, a microcontroller, a microcomputer, a programmable logic controller (PLC), an application specific integrated circuit, and other programmable circuits. Additionally, the memory device(s)  60  may generally comprise memory element(s) including, but not limited to, computer readable medium (e.g., random access memory (RAM)), computer readable non-volatile medium (e.g., a flash memory), a compact disc-read only memory (CD-ROM), a magneto-optical disk (MOD), a digital versatile disc (DVD), and/or other suitable memory elements. The memory  60  can store information accessible by processor(s)  58 , including instructions that can be executed by processor(s)  58 . For example, the instructions can be software or any set of instructions that when executed by the processor(s)  58 , cause the processor(s)  58  to perform operations. For the embodiment depicted, the instructions may include a software package configured to operate the system to, e.g., execute the exemplary methods described below. 
     Referring again to  FIG.  4   , the control system  50  additionally includes a user interface  62  operably connected to the controller  52 . For the embodiment depicted, e.g., in  FIG.  4   , the user interface  62  is configured in wired communication with the controller  52 . However, in other exemplary embodiments, the user interface  62  may additionally or alternatively be wirelessly connected to the controller  52  via one or more suitable wireless communication networks (such as the exemplary wireless communication network  54  described above). In certain exemplary embodiments, user interface  62  may be configured as the user interface panel  154  and plurality of controls, e.g., knobs  156 , on the cooktop appliance  100  (see, e.g.,  FIG.  1   ). Additionally, or alternatively, the user interface  62  may be configured as an external computing device or remote user interface device, such as a smart phone, tablet, or other device capable of connecting to the controller  52  of the exemplary control system  50 . For example, in some embodiments, the remote user interface may be an application or “app” executed by a remote user interface device such as a smart phone or tablet. Signals generated in controller  52  operate the cooktop appliance  100  in response to user input via the user interface  62 . 
     Further, the controller  52  is operably connected to each of the plurality of heating elements  16  for controlling an operating level, such as a supply of power or a flow of fuel, to each of the plurality of heating elements  16  in response to one or more user inputs through the user interface  62  (e.g., user interface panel  154  and/or controls, e.g., knobs  156 ). For example, the controller  52  may be operably connected to each of the plurality of heating elements  16  via a plurality of control devices  64 , e.g., the controller  52  may be operably connected to the plurality of control devices  64 , and each control device  64  may be associated with a respective one of the heating elements  16 . In embodiments wherein one or more of the heating elements  16  are configured as electric resistance heaters, the controller  52  may be operably connected to respective relays, triodes for alternating current, or other devices for controlling an amount of power supplied to such electrical resistance heaters, each of which is an exemplary embodiment of control devices  64 . Alternatively, in embodiments where one or more of the heating elements  16  are configured as induction heating elements, the controller  52  may be operably connected to respective current control devices, e.g., the control devices  64  operably connected to controller  52  may be respective current control devices for each induction heating element. As another example, in embodiments wherein one or more of the heating elements  16  are configured as gas burners, the control devices  64  may include one or more gas supply valves fluidly coupled to each gas burner for selectively adjusting or restricting, e.g., cutting off, a flow of fuel to each gas burner from a fuel supply. 
     According to various embodiments of the present disclosure, the cooktop appliance  100  may be configured for a precision cooking mode and/or methods of operating the cooktop appliance  100  may include precision cooking mode. Precision cooking mode generally includes a closed-loop control algorithm used to automatically (e.g., without user input such as adjusting the knobs  156 ) adjust the heating levels of one or more of the heating elements  16 . Utilizing temperature measurements from one or both of the temperature sensors  28  and  30 , controller  52  may adjust the control device(s)  64  associated with the heating element  16  currently in use. For example, the user may turn on the closed loop control system by initiating precision cooking mode, such as by pressing or otherwise manipulating a corresponding one of the inputs or controls of the user interface  62 . Such inputs and/or controls of the user interface  62  may be also used to input a user-defined set temperature or target temperature for the cooking operation. 
     When the closed loop control system is activated, controller  52  receives the temperature measurements from temperature sensor  28  and/or  30  and compares the temperature measurements to a target temperature, e.g., the user-defined set temperature. In order to reduce a difference between the temperature measurements from the temperature sensor  28  and/or  30  and the set temperature, controller  52  adjusts the respective control device  64 . Thus, the heat output provided by the heating element  16  may be regulated by the closed loop control system, e.g., without additional user input and/or monitoring. 
     A user may establish the set temperature via the user interface  62 , e.g., the user interface may include knobs  156 , inputs  157 , and a display  155 , as in the illustrated example embodiment of  FIG.  2   . Controller  52  is in communication with user interface  62  and is configured to receive the user-determined set temperature from user interface  62 . User interface  62  may correspond to user interface panel  154  and/or controls, e.g., knobs  156 , in certain example embodiments. Thus, the user may, for example, utilize keys  157  on user interface panel  154  and/or a rotary position of one of the knobs  156  to establish the set temperature. In such example embodiments, user interface  62  is positioned on top panel  142  and may be in communication with controller  52  via a wiring harness. As another example, user interface  62  may also or instead correspond to an application on a smartphone or other device, and the user may utilize the application to establish the set temperature. In such example embodiments, user interface  62  may be in wireless communication with controller  52 , e.g., via a Bluetooth® or Wi-Fi® connection. 
     Turning now to  FIG.  5   , an example method  500  of operating a cooktop appliance, such as the example appliance  100  described above, is illustrated. The method  500  may include a step  510  of receiving a first user-determined set temperature from a user interface, e.g., user interface  62 , of the cooktop appliance. The method  500  may also include a step  520  of receiving a precision mode initiation signal. The precision mode initiation signal may be received from the user interface, e.g., user interface panel  154  and/or knobs  156 . The precision mode initiation signal may represent or correspond to a user request for precision cooking mode based on a user pressing a precision cooking mode key or button  157  or otherwise entering the request via the user interface  62 . It will be understood that the precision cooking mode includes a target temperature, e.g., the first user-determined set temperature received from the user interface at step  510 . 
     The precision cooking mode utilizes a closed-loop control system, which may operate or adjust the cooktop appliance based on input from a temperature sensor. Thus, exemplary embodiments of the method  500  may also include a step  530  of receiving a temperature measurement from the temperature sensor. Step  530  may be performed after step  520  of receiving the precision mode initiation signal, such as immediately after receiving the precision mode initiation signal and/or before activating or adjusting the heating element in the precision cooking operation. 
     As illustrated for example at step  540  in  FIG.  5   , the method  500  may further include determining a first set of parameters of a closed-loop algorithm for operation of the heating element. The first set of parameters may correspond to the mathematical difference between the first user-determined set temperature and the temperature measurement, e.g., the mathematical difference may be determined by subtracting the temperature measurement from the first user-determined set temperature. 
     As illustrated in  FIG.  5   , the method  500  may further include a step  550  of inputting the first user-determined set temperature and the temperature measurement into the closed-loop control algorithm. The temperature measurement may be measured with one or both of the temperature sensors  28  and  30  described above, or one or more other suitable temperature sensor(s) configured to measure a temperature at the utensil heated by the heating element. Additionally, the temperature measurement may be iterated or repeated and the closed-loop algorithm updated accordingly (such as inputting the iterated or repeated then-current temperature measurements into the algorithm and generating additional outputs from the algorithm, as described below) throughout the precision cooking mode operation. 
     Turning now to  FIG.  6   , the method  500  may further include a step  560  of determining a first output of the closed-loop control algorithm using the first set of parameters corresponding to the mathematical difference between the first user-determined set temperature and the temperature measurement, and a step  570  of adjusting operation of the heating element according to the first output of the closed-loop control algorithm. 
     Thus, those of ordinary skill in the art will recognize that the precision cooking mode generally includes automated operation of the heating element according to one or more outputs of the closed-loop control algorithm. The output(s) of the closed-loop control algorithm are based on the set temperature and temperature feedback, e.g., multiple temperature measurements each of which reflects a then-current temperature, over time throughout the precision cooking mode operation. Further, those of ordinary skill in the art will understand that such closed-loop control generally includes comparing the current temperature measurement to the user-determined set temperature and generating output of the closed-loop control algorithm based on the comparison of the current temperature measurement to the user-determined set temperature. Such comparing and output-generating steps may be repeated, e.g., continuously, and the heating level of the heating element adjusted accordingly, throughout the precision cooking mode operation. 
     Referring again to  FIG.  6   , the method  500  may further include, e.g., as illustrated at step  580  in  FIG.  6   , receiving a second user-determined set temperature from the user interface of the cooktop appliance after receiving the first user-determined set temperature. For example, the second user-determined set temperature may be received after adjusting the operation of the heating element according to the first output of the closed-loop control algorithm. The second user-defined set temperature may differ from the first user-defined set temperature. Thus, the method  500  may also include additional steps to respond and adapt to the changed target temperature, e.g., to the new and different second user-defined set temperature. 
     For example, as illustrated in  FIG.  6   , method  500  may include a step  590  of determining a second set of parameters of the closed-loop algorithm for operation of the heating element based on the second user-determined set temperature, a step  600  of determining a second output of the closed-loop control algorithm using the second set of parameters, and a step  610  of adjusting operation of the heating element according to the second output of the closed-loop control algorithm. 
     In some embodiments, determining the second set of parameters of the closed-loop algorithm may include comparing the second user-determined set temperature and the first user-determined set temperature. In such embodiments, the determining step  590  may further include selecting a high temperature set of parameters when the second user-determined set temperature is greater than the first user-determined set temperature and selecting a low temperature set of parameters when the second user-determined set temperature is less than the first user-determined set temperature. 
     In some embodiments, the closed-loop control algorithm may be a proportional-integral-derivative (PID) control loop. In such embodiments, the method  500  may further include, after comparing the second user-determined set temperature and the first user-determined set temperature, resetting the accumulated error in the control algorithm, e.g., resetting integral term of the PID control loop. For example, in some embodiments, the I term of the PID control loop may be reset when the second user-determined set temperature is less than the first user-determined set temperature. Moreover, in some embodiments, when the second user-determined set temperature is less than the first user-determined set temperature the low temperature set of parameters mentioned above may be applied after resetting the integral term. 
     In additional embodiments where the closed-loop control algorithm is a PID control loop, the temperature measurement of step  530  may be a first temperature measurement, and the method  500  may further include receiving a second temperature measurement from the temperature sensor after receiving the second user-determined set temperature. In such embodiments, the determined first set of parameters may be PID gains corresponding to the mathematical difference between the first user-determined set temperature and the first temperature measurement, and the determined second set of parameters may be PID gains corresponding to the mathematical difference between the second user-determined set temperature and the second temperature measurement. 
     In some embodiments, the temperature measurement of step  530  may be a first temperature measurement and the method  500  may further include receiving a second temperature measurement from the temperature sensor after receiving the second user-determined set temperature. In such embodiments, the second set of parameters of the closed-loop algorithm for operation of the heating element in step  590  corresponds to the mathematical difference between the second user-determined set temperature and the second temperature measurement. Such embodiments may further include inputting the second user-determined set temperature and the second temperature measurement into the closed-loop control algorithm after determining the second set of parameters, and determining the second output of the closed-loop control algorithm may include comparing the second temperature measurement to the second user-determined set temperature and generating the output of the closed-loop algorithm based on the comparison of the second temperature measurement to the second user-determined set temperature using the second set of parameters of the closed-loop algorithm. 
     As mentioned above, the heating element or elements may be any suitable type of heating element. For example, in some embodiments, the heating element may be or include a gas burner. In such embodiments, adjusting operation of the heating element according to the first output and the second output of the closed-loop control algorithm may each include adjusting a position of a fuel supply valve coupled to the gas burner. As another example, in additional embodiments, the heating element(s) may also or instead be or include an electric heating element. In such embodiments, adjusting operation of the heating element according to the first output and the second output of the closed-loop control algorithm may each include adjusting a level of electric power supplied to the heating element. 
     This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.