An oven control method

Abstract

This application provides a control method for an oven. The oven has an upper heating element and a lower heating element. When the oven is working, the main heating element, auxiliary heating element, and PID coefficients are determined based on the target temperatures of the upper and lower heating elements. The duty cycle of the main heating element is calculated using a PID algorithm, and the duty cycle of the auxiliary heating element is calculated based on the duty cycle of the main heating element. The power of the auxiliary heating element is controlled by the power of the main heating element, while the power of the main heating element is controlled by the target temperatures of the upper and lower heating elements. The power of the upper and lower heating elements changes in synergy, ensuring that the core temperature of the oven always matches the target temperature of the main heating element, achieving a high degree of temperature control consistency. Furthermore, each target temperature corresponds to a different PID coefficient, enabling more precise temperature control.

Description

Technical Field

[0001] This invention relates to the field of cooking technology, and more specifically, to a method for controlling an oven. Background Technology

[0002] As people's living standards continue to improve, ovens are gradually entering the kitchens of every household. As a traditional baking product, temperature control has always been a core requirement and selling point of ovens, but the actual temperature control in products is very poor. Although existing ovens claim to have independent PID temperature control for the upper and lower heating elements, the temperature control is not truly independent, using only one or a few sets of temperature control parameters, which cannot adapt to the needs of different temperature control modes.

[0003] When baking food, the upper and lower heating elements are usually set to the same temperature. However, to achieve specific cooking effects, the set temperatures of the upper and lower heating elements may be adjusted. Because the upper and lower heating elements are independently temperature-controlled, their set temperatures differ, resulting in different temperature fields and ultimately different core temperatures in the oven. For example, when baking food at 200℃, baking bread requires both the upper and lower heating elements to be set to 200℃ to ensure even baking, while baking pizza requires the lower heating element set to 200℃ and the upper heating element set to 180℃ to achieve a charred bottom surface. However, because the core temperature is greatly affected by the temperature field, the actual core temperature of the oven may not reach 200℃ when baking pizza, and it may even be undercooked, significantly impacting the user experience. Summary of the Invention

[0004] One of the main objectives of this application is to provide a method for controlling an oven to solve the problem of inaccurate temperature control in existing ovens.

[0005] To address the aforementioned technical problems, this application provides a control method for an oven, wherein the oven has a cooking cavity, a heating element and a temperature sensor are disposed within the cooking cavity, the temperature sensor is used to detect the real-time temperature of the cooking cavity, and the heating element includes an upper heating element and a lower heating element. The control method further comprises:

[0006] Obtain the target temperature of the upper heating element and the target temperature of the lower heating element;

[0007] The PID coefficients are determined based on the target temperatures of the upper and lower heating elements.

[0008] The main heating element and auxiliary heating element are determined based on the target temperatures of the upper heating element and the lower heating element.

[0009] Obtain the real-time temperature of the cooking cavity;

[0010] The first duty cycle D1 is calculated based on the PID algorithm, and the second duty cycle D2 is calculated based on the first duty cycle.

[0011] The main heating element is controlled to heat at a first duty cycle D1, and the auxiliary heating element is controlled to heat at a second duty cycle D2, so that the core temperature of the oven is consistent with the target temperature of the main heating element.

[0012] Preferably, the control method includes:

[0013] Get the cooking mode selected by the user;

[0014] The target temperatures for the upper heating element and the lower heating element are determined based on the cooking mode.

[0015] Preferably, the control method further includes:

[0016] When the target temperature of the upper heating element is greater than or equal to the target temperature of the lower heating element, the upper heating element is determined to be the main heating element and the lower heating element is determined to be the auxiliary heating element.

[0017] When the target temperature of the lower heating element is greater than the target temperature of the upper heating element, the lower heating element is determined to be the main heating element and the upper heating element is determined to be the auxiliary heating element.

[0018] Preferably, the temperature sensor includes an upper temperature sensor corresponding to the upper heating element and a lower temperature sensor corresponding to the lower heating element, and the control method further includes:

[0019] The temperature sensor corresponding to the main heating element is selected to detect the real-time temperature of the cooking cavity.

[0020] Preferably, when the target temperature of the upper heating element is zero or the target temperature of the lower heating element is zero, the control method includes:

[0021] Second duty cycle = First duty cycle * ((maximum set temperature - minimum set temperature + second constant) - (main heating element target temperature - minimum set temperature - second constant)) / (maximum set temperature - minimum set temperature + second constant) - First duty cycle * (main heating element target temperature - minimum set temperature - second constant) / (maximum set temperature - minimum set temperature + second constant) / First constant.

[0022] Preferably, when both the target temperature of the upper heating element and the target temperature of the lower heating element are not zero, and the target temperature of the upper heating element is greater than the target temperature of the lower heating element or the target temperature of the lower heating element is greater than the target temperature of the upper heating element, the control method includes:

[0023] Second duty cycle = First duty cycle * ((maximum set temperature - minimum set temperature) - (main heating element target temperature - auxiliary heating element target temperature)) / (maximum set temperature - minimum set temperature) - main heating element duty cycle * (main heating element target temperature - auxiliary heating element target temperature) / (maximum set temperature - minimum set temperature) / third constant.

[0024] Preferably, the PID coefficients of the oven are PID[X, Y], where X represents the target temperature of the upper heating element and Y represents the target temperature of the lower heating element. The control method includes:

[0025] The limit coefficients of the oven are obtained through debugging, and the limit coefficients include PID[Tmax, Tmax], PID[Tmin, Tmin], PID[Tmax, 0], PID[Tmin, 0], PID[0, Tmax], and PID[0, Tmin].

[0026] PID[X,Y] is calculated based on the limiting coefficients.

[0027] Where Tmax is the maximum set temperature and Tmin is the minimum set temperature.

[0028] Preferably, the control method includes: when the target temperature of the upper heating element is T1 and the target temperature of the lower heating element is T2:

[0029] If T1=T2≠0, then calculate PID[T1,T2] based on PID[Tmax,Tmax] and PID[Tmin,Tmin].

[0030] If T1≠0 and T2=0, then calculate PID[T1, T2] based on PID[Tmax, 0] and PID[Tmin, 0].

[0031] If T1=0 and T2≠0, then calculate PID[T1, T2] based on PID[0, Tmax] and PID[0, Tmin].

[0032] If T1 > T2 ≠ 0, then calculate PID[T1, T2] based on PID[T1, T1] and PID[T1, 0].

[0033] If T2 > T1 ≠ 0, then calculate PID[T1, T2] based on PID[T2, T2] and PID[0, T2].

[0034] Preferably, the upper heating tube and the lower heating tube are heated in staggered phases within the same heating cycle.

[0035] Preferably, the oven further includes a voltage detection device, and the control method includes:

[0036] Obtain the real-time voltage U of the power grid 实时 ;

[0037] According to U 实时 Constant power correction is performed on the first duty cycle and the second duty cycle.

[0038] Compared with the prior art, this application has the following technical effects:

[0039] 1. In existing technologies, the upper and lower heating elements are independently temperature-controlled, and their heating power does not affect each other. This prevents adjustments based on the different target temperatures of the upper and lower heating elements, resulting in significant differences in the oven's core temperature. This application determines PID coefficients based on the target temperatures of the upper and lower heating elements, uses a PID algorithm to calculate the duty cycle of the main heating element, and calculates the duty cycle of the auxiliary heating element based on the main heating element's duty cycle. This ensures that the oven's core temperature matches the target temperature of the main heating element. The auxiliary heating element's power is controlled by the main heating element's power, which in turn is controlled by the target temperatures of both the upper and lower heating elements. This setup allows the power of the upper and lower heating elements to change in tandem, ensuring that the oven's core temperature is consistent when the main heating element's target temperature is the same, achieving a high degree of temperature control consistency. Furthermore, each target temperature corresponds to a different PID coefficient, enabling more precise temperature control.

[0040] 2. In the same heating cycle, the upper heating tube and the lower heating tube are heated in staggered shifts, which avoids the overshoot caused by the simultaneous heating of the upper and lower heating tubes and the concentrated temperature rise. This achieves precise temperature control.

[0041] 3. This application only requires debugging to obtain the limit coefficient of the oven to obtain the PID coefficients corresponding to different target temperatures, which greatly improves the debugging efficiency.

[0042] 4. In this application, when the user sets a single heating tube to work, another heating tube is turned on for temperature compensation, so that the user-set single-tube heating furnace core temperature can also reach the target temperature.

[0043] 5. The oven of this application has a voltage detection device and performs constant power correction on the first duty cycle and the second duty cycle according to the real-time voltage of the power grid. The heating element generates the same amount of heat in the same time period, and the temperature of the oven is not affected by the fluctuation of the power grid voltage. Attached Figure Description

[0044] Figure 1 This is the flowchart for this application. Detailed Implementation

[0045] This application describes several embodiments, but these descriptions are exemplary and not restrictive, and it will be apparent to those skilled in the art that many more embodiments and implementations are possible within the scope of the embodiments described herein. Although many possible combinations of features are shown in the drawings and discussed in the detailed description, many other combinations of the disclosed features are also possible. Unless specifically limited, any feature or element of any embodiment may be used in combination with, or may replace, any feature or element of any other embodiment.

[0046] This application includes and contemplates combinations of features and elements known to those skilled in the art. The embodiments, features, and elements disclosed in this application may also be combined with any conventional features or elements to form a unique inventive scheme as defined by the claims. Any feature or element of any embodiment may also be combined with features or elements from other inventive schemes to form another unique inventive scheme as defined by the claims. Therefore, it should be understood that any feature shown and / or discussed in this application may be implemented individually or in any suitable combination. Therefore, the embodiments are not limited except by the limitations imposed by the appended claims and their equivalents. Furthermore, various modifications and changes may be made within the scope of the appended claims.

[0047] Furthermore, in describing representative embodiments, the specification may have presented methods and / or processes as a specific sequence of steps. However, the method or process should not be limited to the specific order of steps described herein, to the extent that it does not depend on such a specific order. As will be understood by those skilled in the art, other sequences of steps are also possible. Therefore, the specific order of steps set forth in the specification should not be construed as a limitation of the claims. Moreover, the claims concerning the method and / or process should not be limited to the steps performed in the written order, and those skilled in the art will readily understand that these orders can be varied and still remain within the spirit and scope of the embodiments of this application.

[0048] Example 1

[0049] The oven in this embodiment has a shell and a cooking cavity. The cooking cavity is equipped with heating elements and a temperature sensor. The heating elements include an upper heating element and a lower heating element. The temperature sensor is used to detect the real-time temperature of the oven's cooking cavity.

[0050] The oven in this embodiment has two sets of heating elements, upper and lower. Users can set the working status of the two sets of heating elements according to their cooking needs. Users can set to turn on only the upper heating element or the lower heating element, or they can set to turn on both the upper and lower heating elements at the same time. When the upper and lower heating elements are set to turn on at the same time, the target temperature of the upper heating element and the target temperature of the lower heating element can be the same or different.

[0051] The oven in this embodiment has a maximum set temperature Tmax and a minimum set temperature Tmin. Users can adjust the target temperature of the upper and lower heating elements between the maximum set temperature Tmax and the minimum set temperature Tmin.

[0052] The oven control method in this embodiment includes:

[0053] S1: Obtain the target temperature of the upper heating element and the target temperature of the lower heating element;

[0054] S2: Determine the PID coefficients based on the target temperatures of the upper and lower heating elements;

[0055] S3: Determine the main heating element and auxiliary heating element based on the target temperature of the upper heating element and the target temperature of the lower heating element;

[0056] S4: Obtain the real-time temperature of the cooking cavity;

[0057] S5: Calculate the first duty cycle D1 according to the PID algorithm, and calculate the second duty cycle D2 according to the first duty cycle D1;

[0058] S6: Control the main heating element to heat at a first duty cycle D1, and control the auxiliary heating element to heat at a second duty cycle D2, so that the core temperature of the oven is consistent with the target temperature of the main heating element.

[0059] When the oven in this embodiment is working, it first reads the target temperatures of the upper and lower heating elements set by the user, then selects the main heating element and the auxiliary heating element according to the target temperatures of the upper and lower heating elements, then determines the PID coefficient of the main heating element according to the target temperatures of the upper and lower heating elements, and uses the PID algorithm to adjust the power of the main heating element according to the real-time temperature of the cooking cavity, and adjusts the power of the auxiliary heating element based on the power of the main heating element.

[0060] In existing technologies, the upper and lower heating elements are independently temperature-controlled, and their heating power does not affect each other. This prevents adjustments based on the different target temperatures of the upper and lower heating elements, resulting in significant differences in the oven's core temperature. This application determines PID coefficients based on the target temperatures of the upper and lower heating elements, uses a PID algorithm to calculate the duty cycle of the main heating element, and calculates the duty cycle of the auxiliary heating element based on the main heating element's duty cycle. This ensures that the oven's core temperature matches the target temperature of the main heating element. The auxiliary heating element's power is controlled by the main heating element's power, which in turn is controlled by the target temperatures of both the upper and lower heating elements. This setup allows the power of the upper and lower heating elements to change in tandem, ensuring that the oven's core temperature is consistent when the main heating element's target temperature is the same, achieving a high degree of temperature control consistency. Furthermore, each target temperature corresponds to a different PID coefficient, enabling even more precise temperature control.

[0061] In this embodiment, the oven has a knob or button for adjusting the target temperature of the upper and lower heating elements. The user can adjust the knob or button to set the target temperature of the upper and lower heating elements. In other embodiments, the oven has different cooking modes. The target temperatures of the upper and lower heating elements corresponding to different cooking modes are pre-stored in the oven's control device. When the user selects the desired cooking mode, the control device retrieves the target temperatures of the upper and lower heating elements corresponding to that cooking mode.

[0062] In this embodiment, when the target temperature of the upper heating element is greater than or equal to the target temperature of the lower heating element, the upper heating element is selected as the main heating element and the lower heating element as the auxiliary heating element; when the target temperature of the lower heating element is greater than the target temperature of the upper heating element, the lower heating element is selected as the main heating element and the upper heating element as the auxiliary heating element. It is worth noting that when the upper heating element is set to be off, its target temperature is zero; when the lower heating element is set to be off, its target temperature is zero.

[0063] By selecting a heating element with a high temperature setting as the main heating element, users can freely choose the target temperature of the upper and lower heating elements according to the cooking mode. As long as the target temperature of the main heating element is the same as the required cooking temperature, the oven core temperature can be maintained at the required cooking temperature.

[0064] The oven temperature sensor in this embodiment includes an upper temperature sensor corresponding to the upper heating element and a lower temperature sensor corresponding to the lower heating element. When the main heating element is selected, the temperature sensor corresponding to the main heating element is used to detect the real-time temperature of the oven cooking cavity.

[0065] In this embodiment, different target temperatures for the upper and lower heating elements correspond to different PID coefficients. By inputting the target temperatures of the upper and lower heating elements into the corresponding calculation method, the PID coefficients corresponding to different target temperatures of the upper and lower heating elements can be calculated. In this application, the oven pre-stores the correspondence between the target temperatures of the upper and lower heating elements and the PID coefficients. After cooking begins, the oven's control device retrieves the corresponding PID coefficients based on the target temperatures of the upper and lower heating elements, which can effectively reduce the computational load of the control device. Of course, the PID coefficients can also be calculated based on the target temperatures of the upper and lower heating elements after cooking begins.

[0066] The PID coefficients for different upper and lower heating elements are denoted as PID[X, Y], where element X represents the target temperature of the upper heating element and element Y represents the target temperature of the lower heating element. Therefore, PID[220, 80] represents the PID coefficient corresponding to an upper heating element target temperature of 220℃ and a lower heating element target temperature of 80℃; PID[Tmax, Tmax] represents the PID coefficient corresponding to both upper and lower heating elements having the maximum set temperature; PID[Tmin, Tmin] represents the PID coefficient corresponding to both upper and lower heating elements having the minimum set temperature; PID[Tmax, 0] represents the PID coefficient corresponding to an upper heating element target temperature of the maximum set temperature and a lower heating element set to off; PID[0, Tmin] represents the PID coefficient corresponding to an upper heating element set to off and a heating element target temperature of the minimum set temperature, and so on.

[0067] When the target temperature of the upper heating element is T1 and the target temperature of the lower heating element is T2, the corresponding PID coefficient is PID[T1,T2]. PID[T1,T2] includes parameters such as the PID operation period Tpid, proportional coefficient Kp, derivative coefficient Ki, integral coefficient Kd, and temperature compensation value Tp.

[0068] The specific calculation method for PID[T1,T2] is as follows:

[0069] Step 1: Debug and obtain the oven's limit coefficients, including PID[Tmax, Tmax], PID[Tmin, Tmin], PID[Tmax, 0], PID[Tmin, 0], PID[0, Tmax], PID[0, Tmin], etc.

[0070] PID[Tmax, Tmax] includes: PID operation period Tpid_max1, proportional coefficient Kp_max1, derivative coefficient Ki_max1, integral coefficient Kd_max1, temperature compensation value Tp_max1, etc.

[0071] PID[Tmin, Tmin] includes: PID operation period Tpid_min1, proportional coefficient Kp_min1, derivative coefficient Ki_min1, integral coefficient Kd_min1, temperature compensation value Tp_min1, etc.

[0072] PID[Tmax, 0] includes: PID operation period Tpid_max2, proportional coefficient Kp_max2, derivative coefficient Ki_max2, integral coefficient Kd_max2, temperature compensation value Tp_max2, etc.

[0073] PID[Tmin, 0] includes: PID operation period Tpid_min2, proportional coefficient Kp_min2, derivative coefficient Ki_min2, integral coefficient Kd_min2, temperature compensation value Tp_min2, etc.

[0074] PID[0, Tmax] includes: PID operation period Tpid_max3, proportional coefficient Kp_max3, derivative coefficient Ki_max3, integral coefficient Kd_max3, temperature compensation value Tp_max3, etc.

[0075] PID[0, Tmin] includes: PID operation period Tpid_min3, proportional coefficient Kp_min3, derivative coefficient Ki_min3, integral coefficient Kd_min3, temperature compensation value Tp_min3, etc.

[0076] Step 2: Determine the target temperatures of the upper and lower heating elements, and select the corresponding calculation method to calculate PID[T1,T2];

[0077] 1) If T1=T2≠0, then substitute X=T1 into calculation method 1 to calculate PID[T1,T2];

[0078] 2) If T1≠0 and T2=0, then substitute X=T1 into calculation method 2 to calculate PID[T1,T2];

[0079] 3) If T1=0 and T2≠0, then substitute Y=T2 into calculation method 3 to calculate PID[T1,T2];

[0080] 4) If T1 > T2 ≠ 0, then substitute X = T1 and Y = T2 into calculation method 4 to calculate PID[T1, T2].

[0081] 5) If T2 > T1 ≠ 0, then substitute X = T1, Y = T2 into calculation method 5 to calculate PID[T1, T2].

[0082] Calculation method 1:

[0083] Tpid = Tpid_max1+(Tpid_min1 - Tpid_max1)*(Tmax - X) / (Tmax - Tmin);

[0084] Kp = Kp_min1+(Kp_max1 - Kp_min1)*(X - Tmin) / (Tmax - Tmin);

[0085] Ki = Ki_min1+(Ki_max1 - Ki_min1)*(X - Tmin) / (Tmax - Tmin);

[0086] Kd = Kd_max1+(Kd_min1 - Kd_max1)*(Tmax - X) / (Tmax - Tmin);

[0087] Tp = Tp_min1+(Tp_max1 - Tp_min1)*(X - Tmin) / (Tmax - Tmin);

[0088] Calculation method 2:

[0089] Tpid = Tpid_max2+(Tpid_min2 - Tpid_max2)*(Tmax - X) / (Tmax - Tmin);

[0090] Kp = Kp_min2+(Kp_max2 - Kp_min2)*(X - Tmin) / (Tmax - Tmin);

[0091] Ki = Ki_min2+(Ki_max2 - Ki_min2)*(X - Tmin) / (Tmax - Tmin);

[0092] Kd = Kd_max2+(Kd_min2 - Kd_max2)*(Tmax - X) / (Tmax-Tmin);

[0093] Tp = Tp_min2+(Tp_max2 - Tp_min2)*(X-Tmin) / (Tmax - Tmin);

[0094] Calculation method three:

[0095] Tpid = Tpid_max2+(Tpid_min2 - Tpid_max2)*(Tmax - Y) / (Tmax - Tmin);

[0096] Kp = Kp_min3+(Kp_max3 - Kp_min3)*(Y - Tmin) / (Tmax - Tmin);

[0097] Ki= Ki_min3+(Ki_max3-Ki_min3)* (Y-Tmin) / (Tmax-Tmin);

[0098] Kd=Kd_max3+(Kd_min3-Kd_max3)* (Tmax-Y) / (Tmax-Tmin);

[0099] Tp= Tp_min3+(Tp_max3-Tp_min3)* (Y-Tmin) / (Tmax-Tmin).

[0100] Calculation method 4:

[0101] Calculate PID[T1,T1] according to calculation method 1, including PID operation period Tpid1, proportional coefficient Kp1, derivative coefficient Ki1, integral coefficient Kd1, temperature compensation value Tp1, etc.

[0102] PID[T1,0] is calculated according to calculation method 2, including PID operation period Tpid2, proportional coefficient Kp2, derivative coefficient Ki2, integral coefficient Kd2, temperature compensation value Tp2, etc.

[0103] If Tp2≥Tp1, then Tp=Tp2-(Tp2-Tp1)*[(Tmax-Tmin)-(T1-T2)] / (Tmax-Tmin);

[0104] If TP2 < Tp1, then Tp = Tp1 + (Tp1 - Tp2) * [(Tmax - Tmin) - (T1 - T2)] / (Tmax - Tmin);

[0105] The PID operation period Tpid, proportional coefficient Kp, derivative coefficient Ki, integral coefficient Kd, etc., are calculated using the same method as the temperature compensation value Tp.

[0106] Calculation method 5:

[0107] Calculate PID[T2,T2] according to calculation method 1, including PID operation period Tpid3, proportional coefficient Kp3, derivative coefficient Ki3, integral coefficient Kd3, temperature compensation value Tp3, etc.

[0108] PID[0,T2] is calculated according to calculation method 3, including PID operation period Tpid4, proportional coefficient Kp4, derivative coefficient Ki4, integral coefficient Kd4, temperature compensation value Tp4, etc.

[0109] If Tp4≥Tp3, then Tp=Tp4-(Tp4-Tp3)*[(Tmax-Tmin)-(T2-T1)] / (Tmax-Tmin);

[0110] If TP4 < Tp3, then Tp = Tp3 + (Tp3 - Tp4) * [(Tmax - Tmin) - (T2 - T1)] / (Tmax - Tmin);

[0111] The PID operation period Tpid, proportional coefficient Kp, derivative coefficient Ki, integral coefficient Kd, etc., are calculated using the same method as the temperature compensation value Tp.

[0112] For example, PID[120,80] is calculated using PID[120,120] and PID[120,0], and PID[80,120] is calculated using PID[120,120] and PID[0,120].

[0113] Using the above-mentioned PID coefficient calculation method, only 6 sets of PID coefficients need to be obtained through debugging to obtain the PID coefficients for different target temperatures of the upper and lower heating tubes, which greatly improves the debugging efficiency. Moreover, each target temperature corresponds to different PID temperature control parameters, further improving the accuracy of oven temperature control.

[0114] In this application, when the user sets only the upper heating element or only the lower heating element to operate, the auxiliary heating element is activated for power compensation. The first duty cycle is calculated using the PID formula, and the second duty cycle = first duty cycle * ((maximum set temperature - minimum set temperature + second constant) - (main heating element target temperature - minimum set temperature - second constant)) / (maximum set temperature - minimum set temperature + second constant) - first duty cycle * (main heating element target temperature - minimum set temperature - second constant) / (maximum set temperature - minimum set temperature + second constant) / first constant, where the first constant is any value between 2 and 10, and the second constant is preferably the temperature step size. When a single heating element is set to operate, the other heating element is activated for temperature compensation, and the core temperature of the single-element heating oven can also reach the target temperature.

[0115] In this application, when the user sets two heating elements to heat simultaneously and the target temperatures of the upper and lower heating elements are different, the first duty cycle is calculated using the PID formula, and the second duty cycle is calculated as follows: first duty cycle * ((maximum set temperature - minimum set temperature) - (main heating element target temperature - auxiliary heating element target temperature)) / (maximum set temperature - minimum set temperature) - first duty cycle * (main heating element target temperature - auxiliary heating element target temperature) / (maximum set temperature - minimum set temperature) / third constant, where the third constant is any value between 1 and 6.

[0116] The oven described in this application employs staggered heating of the upper and lower heating elements within the same heating cycle during operation. Specifically, the upper heating element heats in the early part of the heating cycle, while the lower heating element heats in the later part, or vice versa. For example, in a 30-second heating cycle with a 50% duty cycle for the upper heating element and a 40% duty cycle for the lower heating element, the upper heating element heats for the first 15 seconds of the cycle, and the lower heating element heats for the last 12 seconds. This staggered heating within the same heating cycle ensures power output throughout the cycle, but at a relatively low level, achieving an average temperature and extending the relay control cycle.

[0117] The oven in this embodiment also has a voltage detection device, which detects the real-time voltage of the power grid and performs constant power correction on the first duty cycle and the second duty cycle in real time according to the real-time voltage U of the power grid.

[0118]

[0119]

[0120] Wherein, U is the rated voltage of the oven, D1 is the first duty cycle under the rated voltage, and D2 is the second duty cycle under the rated voltage.

[0121] It will be understood by those skilled in the art that all or some of the steps, systems, or devices in the computational methods disclosed above, and the functional modules / units therein, can be implemented as software, firmware, hardware, or suitable combinations thereof. In hardware implementations, the division between functional modules / units mentioned in the above description does not necessarily correspond to the division of physical components; for example, a physical component may have multiple functions, or a function or step may be performed collaboratively by several physical components. Some or all components may be implemented as software executed by a processor, such as a digital signal processor or microprocessor, or as hardware, or as integrated circuits, such as application-specific integrated circuits (ASICs). Such software may be distributed on a computer-readable medium, which may include computer storage media (or non-transitory media) and communication media (or transient media). As is known to those skilled in the art, the term computer storage media includes volatile and non-volatile, removable and non-removable media implemented in any computational method or technology for storing information (such as computer-readable instructions, data structures, program modules, or other data). Computer storage media include, but are not limited to, RAM, ROM, EEPROM, flash memory or other memory technologies, CD-ROM, digital versatile disc (DVD) or other optical disc storage, magnetic cartridges, magnetic tape, disk storage or other magnetic storage devices, or any other medium that can be used to store desired information and can be accessed by a computer. Furthermore, it is well known to those skilled in the art that communication media typically contain computer-readable instructions, data structures, program modules, or other data in modulated data signals such as carrier waves or other transmission mechanisms, and may include any information delivery medium.

Claims

1. A method for controlling an oven, the oven having a cooking cavity, wherein a heating element and a temperature sensor are disposed within the cooking cavity, the temperature sensor being used to detect the real-time temperature of the cooking cavity, and the heating element comprising an upper heating element and a lower heating element, characterized in that, The control method further includes: Obtain the target temperature of the upper heating element and the target temperature of the lower heating element; The PID coefficients are determined based on the target temperatures of the upper and lower heating elements. The main heating element and the auxiliary heating element are determined based on the target temperatures of the upper heating element and the lower heating element. When the target temperature of the upper heating element is greater than or equal to the target temperature of the lower heating element, the upper heating element is determined to be the main heating element and the lower heating element is determined to be the auxiliary heating element. When the target temperature of the lower heating element is greater than the target temperature of the upper heating element, the lower heating element is determined to be the main heating element and the upper heating element is determined to be the auxiliary heating element. Obtain the real-time temperature of the cooking cavity; The first duty cycle D1 is calculated based on the PID algorithm, and the second duty cycle D2 is calculated based on the first duty cycle D1. When the target temperature of the upper heating element is zero or the target temperature of the lower heating element is zero, the second duty cycle = the first duty cycle * ((maximum set temperature - minimum set temperature + second constant) - (main heating element target temperature - minimum set temperature - second constant)) / (maximum set temperature - minimum set temperature + second constant) - the first duty cycle * (main heating element target temperature - minimum set temperature - second constant) / (maximum set temperature - minimum set temperature + second constant) / first constant; The main heating element is controlled to heat at a first duty cycle D1, and the auxiliary heating element is controlled to heat at a second duty cycle D2, so that the core temperature of the oven is consistent with the target temperature of the main heating element. The first constant takes any value between 2 and 10, and the second constant is the temperature step size.

2. The oven control method according to claim 1, characterized in that, The control method includes: Get the cooking mode selected by the user; The target temperatures for the upper heating element and the lower heating element are determined based on the cooking mode.

3. The oven control method according to claim 1, characterized in that, The temperature sensor includes an upper temperature sensor corresponding to the upper heating element and a lower temperature sensor corresponding to the lower heating element, and the control method further includes: The temperature sensor corresponding to the main heating element is selected to detect the real-time temperature of the cooking cavity.

4. The oven control method according to claim 1, characterized in that, When both the target temperatures of the upper heating element and the lower heating element are not zero, and the target temperature of the upper heating element is greater than the target temperature of the lower heating element or vice versa, the control method includes: Second duty cycle = First duty cycle * ((maximum set temperature - minimum set temperature) - (main heating element target temperature - auxiliary heating element target temperature)) / (maximum set temperature - minimum set temperature) - main heating element duty cycle * (main heating element target temperature - auxiliary heating element target temperature) / (maximum set temperature - minimum set temperature) / third constant, where the third constant is any value between 1 and 6.

5. The oven control method according to claim 1, characterized in that, The control method includes: the oven's PID coefficients are PID[X, Y], where X represents the target temperature of the upper heating element and Y represents the target temperature of the lower heating element. The control method includes: The limit coefficients of the oven are obtained through debugging, and the limit coefficients include PID[Tmax, Tmax], PID[Tmin, Tmin], PID[Tmax, 0], PID[Tmin, 0], PID[0, Tmax], and PID[0, Tmin]. PID[X,Y] is calculated based on the limiting coefficients. Where Tmax is the maximum set temperature and Tmin is the minimum set temperature.

6. The oven control method according to claim 5, characterized in that, The control method includes: When the target temperature of the upper heating element is T1 and the target temperature of the lower heating element is T2: If T1=T2≠0, then calculate PID[T1,T2] based on PID[Tmax,Tmax] and PID[Tmin,Tmin]. If T1≠0 and T2=0, then calculate PID[T1, T2] based on PID[Tmax, 0] and PID[Tmin, 0]. If T1=0 and T2≠0, then calculate PID[T1, T2] based on PID[0, Tmax] and PID[0, Tmin]. If T1 > T2 ≠ 0, then calculate PID[T1, T2] based on PID[T1, T1] and PID[T1, 0]. If T2 > T1 ≠ 0, then calculate PID[T1, T2] based on PID[T2, T2] and PID[0, T2].

7. The oven control method according to any one of claims 1-6, characterized in that, The control method further includes: Within the same heating cycle, the upper heating tube and the lower heating tube are heated in staggered shifts.

8. The oven control method according to claim 7, characterized in that, The oven also has a voltage detection device, and the control method includes: Obtain the real-time voltage of the power grid, Ureal-time. The first and second duty cycles are constantly corrected based on U in real time.

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