A dynamic control method for a rice cooker and its application in smart home appliances.

Abstract

This invention relates to the field of smart home appliance technology, and particularly to a dynamic control method for a rice cooker and a smart home appliance using the same method. The control method acquires the rice cooker's operating state parameters and preset characteristic thresholds; determines the rice cooker's current quasi-operation stage and its posterior probability based on these parameters and thresholds; if the posterior probability of the quasi-operation stage is not less than the preset probability, the quasi-operation stage is designated as the target operation stage; acquires preset control coefficients and a target temperature for the target operation stage; and determines a power adjustment term based on these coefficients, temperature, and target temperature; and adjusts the heating power based on the power adjustment term to control the rice cooker's operation using the adjusted power. This allows for dynamic identification of the operation stage, intelligent adjustment of the heating strategy, and improved cooking accuracy.

Description

Technical Field

[0001] This invention relates to the field of smart home appliance technology, and in particular to a dynamic control method for a rice cooker and smart home appliances using the same method. Background Technology

[0002] With the improvement of people's living standards and the promotion and popularization of technologies such as the Internet, big data, artificial intelligence, and voice interaction, more and more traditional lifestyles have changed, and enjoying the convenience brought by technology has become a trend. While bringing more convenience to users, various home appliances are also becoming increasingly intelligent. Among them, rice cookers have been upgraded from traditional mechanical timer models to intelligent products based on microprocessor control.

[0003] Currently, smart rice cooker control methods primarily rely on temperature sensors and time control. Some high-end products incorporate fuzzy control, pressure sensors, or multi-stage heating strategies to optimize rice texture. However, these control methods often employ fixed heating programs and simple temperature change threshold judgments, lacking real-time sensing and feedback mechanisms for physical changes within the cooker. Especially under different rice varieties (such as glutinous rice, mixed grains, and germ rice) or varying environmental conditions (altitude, air pressure), the optimal gelatinization and cooking times for rice differ significantly, making traditional methods difficult to adapt. Therefore, there is an urgent need for a control method capable of dynamically identifying the cooking stage and adjusting control parameters in real time to further improve the intelligence level of rice cookers and the consistency of rice texture. Summary of the Invention

[0004] To address the problems of the prior art, this application provides a dynamic control method, device, electronic device, and storage medium for a rice cooker. The technical solution is as follows: On the one hand, a dynamic control method for a rice cooker is provided, the method comprising: The system acquires the operating status parameters and preset characteristic thresholds of the rice cooker; the operating status parameters include running time, pressure, steam rate, temperature, and heating power; the preset characteristic thresholds are used to measure the operating stage of the rice cooker. The current quasi-operation stage of the rice cooker is determined based on the rice cooker's operating status parameters and the preset feature threshold. The posterior probability of the quasi-operation stage is determined based on the operating state parameters of the rice cooker; the posterior probability of the quasi-operation stage represents the probability that the current operating stage of the rice cooker is the quasi-operation stage. If the posterior probability of the quasi-operation phase is not less than the preset probability, the quasi-operation phase is determined as the target operation phase. Obtain the preset control coefficient and target temperature for the target operating phase; and determine the power adjustment term based on the preset control coefficient, the temperature, and the target temperature; The heating power is adjusted based on the power adjustment item so as to control the operation of the rice cooker using the adjusted heating power.

[0005] In one feasible implementation, determining the posterior probability of the quasi-operation phase based on the operating state parameters of the rice cooker includes: The operating status parameters of the rice cooker are subjected to feature processing to form a feature parameter set; the feature parameter set includes multiple feature parameters used to measure the current operating stage of the rice cooker; For each operating stage of the rice cooker, a likelihood function for the operating stage is determined based on the feature parameter set, and a prior probability for the operating stage is obtained; the prior probability of the operating stage represents the probability that the current operating stage is the operating stage under historical cognitive conditions; the likelihood function of the operating stage represents the probability that the feature parameter set is observed under the operating stage. The posterior probability of the quasi-operational stage is determined based on the prior probability and likelihood function of each of the aforementioned operational stages.

[0006] In one feasible implementation, determining the posterior probability of the quasi-operational stage based on the prior probability and likelihood function of each of the operation stages includes: For each operating stage of the rice cooker, the product of the likelihood function and the prior probability of the operating stage is determined as the joint probability of the operating stage; the joint probability represents the probability that the current operating stage is the operating stage and that the observed feature parameter set occurs simultaneously. The joint probability of the quasi-operational stage is determined from the joint probability of each of the aforementioned operational stages; Based on the sum of the joint probabilities of multiple operational phases, the joint probability of the quasi-operational phase is normalized to obtain the posterior probability of the quasi-operational phase.

[0007] In one feasible implementation, the temperature in the operating status parameters includes multiple temperature values ​​during the operating time; the preset control coefficient includes a proportional coefficient, an integral coefficient, and a derivative coefficient; the proportional coefficient represents the response to the current error; the integral coefficient represents the correction term for long-term deviation; the derivative coefficient represents the suppression term for data fluctuation; determining the power adjustment term based on the preset control coefficient and the target temperature includes: The current temperature is determined from the operating status parameters of the rice cooker; The temperature difference is determined based on the target temperature of the target operating phase and the current temperature. A target temperature dataset is determined from the stated temperatures; the target temperature dataset includes temperature values ​​within a preset running time. Based on the target temperature dataset, determine the temperature integral term and the temperature difference change rate term within the preset operating time. The power adjustment term is determined based on the temperature difference, the temperature integral term, the temperature difference change rate term, the proportional coefficient, the integral coefficient, and the derivative coefficient.

[0008] In one feasible implementation, the method further includes: Obtain the current control curve and the historical control curve; the current control curve represents the relationship between the current running time and the current heating power of the rice cooker; the historical control curve represents the relationship between the historical running time and the historical heating power of the rice cooker; the current heating power is the heating power adjusted based on the power adjustment item; Determine whether there is a difference between the current control curve and the historical control curve. If yes, determine the difference between the current control curve and the historical control curve; otherwise, control the rice cooker to work based on the current control curve. The current control curve is adjusted based on the difference terms to obtain the target control curve; The rice cooker is controlled based on the target control curve.

[0009] In one feasible implementation, the operation stages of the rice cooker include a preheating and water absorption stage, a gelatinization transition stage, a gelatinization and expansion stage, a rice cooking stage, and a heat preservation stage; the method further includes: If the current operating stage of the rice cooker is the gelatinization transition stage or the gelation expansion stage, and the stage switching conditions are met, a hysteresis parameter is determined; the hysteresis parameter represents the parameter that delays the switching of the current operating stage. The current control curve is adjusted based on the hysteresis parameter; the current control curve represents the relationship between the current running time and the current heating power of the rice cooker. The rice cooker is controlled based on the adjusted current control curve.

[0010] In one feasible implementation, the hysteresis parameter includes any one or more of the following: the extension of the holding time during the current operating phase, the rate of change of pressure not exceeding a first threshold, and the rate of change of steam rate not exceeding a second threshold.

[0011] In one feasible implementation, the preset feature threshold includes a first type of state threshold and a second type of state threshold; determining the current quasi-operation stage of the rice cooker based on the rice cooker's operating state parameters and the preset feature threshold includes: A first judgment result is determined based on the running time, the pressure, and the first type of state threshold; The second judgment result is determined based on the running time, the steam rate, and the second type of state threshold; The current operating stage of the rice cooker, characterized by the first judgment result and the second judgment result, is determined as the quasi-operating stage.

[0012] On the other hand, a dynamic control system for a rice cooker is provided, which includes a pot body, a temperature sensor, a pressure sensor, a steam rate sensor, a control unit, and a heating device. The temperature sensor is located at the bottom of the pot body and is used to collect the bottom temperature of the pot body; The pressure sensor is used to collect the internal pressure of the pot body; The steam rate sensor is used to collect steam rate data. The heating device is used to heat the pot body; The control unit is electrically connected to the temperature sensor, the pressure sensor, the steam rate sensor, and the heating device, respectively, and is used to execute the above-described dynamic control method for the rice cooker.

[0013] On the other hand, a smart home appliance is provided, which is a rice cooker, and the rice cooker is equipped with the aforementioned dynamic control system for rice cookers.

[0014] This application embodiment acquires the operating state parameters and preset feature thresholds of a rice cooker; the operating state parameters include running time, pressure, steam rate, temperature, and heating power; the preset feature thresholds are used to measure the operating stage of the rice cooker; based on the operating state parameters and the preset feature thresholds, the current quasi-operating stage of the rice cooker is determined; based on the operating state parameters, the posterior probability of the quasi-operating stage is determined; the posterior probability of the quasi-operating stage characterizes the probability that the current operating stage of the rice cooker is the quasi-operating stage; if the posterior probability of the quasi-operating stage is not less than the preset probability, the quasi-operating stage is determined as the target operating stage; a preset control coefficient and target temperature of the target operating stage are acquired; and a power adjustment term is determined based on the preset control coefficient, the temperature, and the target temperature; the heating power is adjusted based on the power adjustment term to control the operation of the rice cooker using the adjusted heating power. In this way, the operating stage can be dynamically identified, and the heating parameters can be dynamically adjusted based on the identified operating stage. This not only enables precise control, but also improves the intelligence and wider application of the rice cooker, and ensures the consistency of the rice's taste. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a flowchart illustrating a dynamic control method for a rice cooker provided in an embodiment of this application; Figure 2 This application provides a pressure-time curve for the cooking stage of a rice cooker. Figure 3 This is a steam rate-time curve of the cooking stage of a rice cooker provided in an embodiment of this application. Detailed Implementation

[0017] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0018] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or server that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or devices.

[0019] It is understood that in the specific embodiments of this application, data such as user information are involved. When the above embodiments of this application are applied to specific products or technologies, user permission or consent is required, and the collection, use and processing of related data must comply with the relevant laws, regulations and standards of the relevant countries and regions.

[0020] Please see Figure 1The diagram illustrates a flowchart of a dynamic control method for a rice cooker according to an embodiment of this application. It should be noted that while this specification provides the operational steps described in the embodiments or flowcharts, more or fewer operational steps may be included based on conventional or non-inventive methods. The order of steps listed in the embodiments is merely one possible execution order among many and does not represent the only possible execution order. In actual system or product execution, the methods shown in the embodiments or drawings can be executed sequentially or in parallel (e.g., in a parallel processor or multi-threaded processing environment). Specifically, as shown... Figure 1 As shown, the method may include: S101: Obtain the working status parameters and preset characteristic thresholds of the rice cooker; the working status parameters include running time, pressure, steam rate, temperature and heating power; the preset characteristic thresholds are used to measure the operating stage of the rice cooker.

[0021] In this embodiment of the application, the rice cooker is equipped with sensors for collecting its working status, such as a temperature sensor, a pressure sensor, a steam rate sensor, and a heating device. The temperature sensor collects the bottom temperature of the pot body; the pressure sensor collects the internal pressure of the pot body; the steam rate sensor collects the steam rate; and the heating device heats the pot body and can obtain the heating power.

[0022] In this embodiment, the rice cooker is further provided with a control unit, which serves as the micro-control module of the rice cooker. It can be connected to the aforementioned sensors and devices to realize data acquisition, processing, and control of the rice cooker's working status.

[0023] In this embodiment, the running time can be denoted as t; the pressure is specifically a dataset of pressure values ​​collected at preset sampling time intervals, i.e., it includes multiple pressure values ​​P; similarly, the steam rate V, temperature T, and heating power W are the steam rate dataset, temperature dataset, and heating power dataset collected at preset sampling time intervals, respectively.

[0024] In this embodiment, the above-mentioned working state parameters may not be limited to the parameters mentioned above, and may also include other parameters as needed, such as pot lid temperature, exhaust port humidity, acoustic boiling signal (pot body micro-vibration), etc., to obtain more accurate and reliable control through more working state parameters.

[0025] The preset feature thresholds can be judgment parameters set by relevant personnel when the rice cooker leaves the factory. Specifically, they may include pressure thresholds, steam rate thresholds, holding time thresholds, pressure standard deviation thresholds, steam rate change rate thresholds, pressure change rate thresholds, etc., which will be discussed in detail below. Any threshold used in step S102 to determine the operating stage is a preset feature threshold. Since the characteristic states of different operating stages of the rice cooker are different, their corresponding feature thresholds are also different. Therefore, the preset feature thresholds here include the feature thresholds for each operating stage.

[0026] S102: Determine the current quasi-operation stage of the rice cooker based on the working status parameters of the rice cooker and the preset feature threshold.

[0027] In one feasible implementation, the preset feature threshold includes a first type of state threshold and a second type of state threshold; determining the current quasi-operation stage of the rice cooker based on the rice cooker's operating state parameters and the preset feature threshold includes: determining a first judgment result based on the operating time, the pressure, and the first type of state threshold; determining a second judgment result based on the operating time, the steam rate, and the second type of state threshold; and determining the current operation stage of the rice cooker characterized by the first judgment result and the second judgment result as the quasi-operation stage.

[0028] The first type of state thresholds may specifically include pressure threshold, pressure change threshold, pressure change rate threshold, pressure standard deviation threshold, and corresponding duration threshold; the second type of state thresholds may specifically include steam rate threshold, steam rate change rate threshold, and corresponding duration threshold.

[0029] The following describes the characteristic states of each operating stage. In this solution, the operating stages of the rice cooker when cooking rice can be divided into five stages: preheating and water absorption stage, gelatinization and transformation stage, gelatinization and expansion stage, rice cooking stage, and heat preservation stage.

[0030] The characteristics of M1 in the preheating absorption stage are set as follows: Within the continuous detection cycle Y1, the pressure change rate ΔP / Δt satisfies the first pressure change rate threshold, and the steam rate V satisfies the first steam rate threshold.

[0031] Wherein, Y1 can be in the minute range, such as 510 seconds; the first pressure change rate threshold is in the range of 0.5~1.0 kPa / s, that is, ΔP1 / Δt1 is in the range of 0.5~1.0 kPa / s, and Δt1 can be in the range of 5~10 s; the first steam rate threshold is ≤2.0 g / min, that is, steam rate V≤2.0 g / min. It should be noted that the first pressure change rate threshold can be adjusted within the range of 0.5-1.0 kPa / s according to the volume of the pot and the accuracy of the sensor, and the first steam rate threshold can be adjusted within the range of 1.5~3.0 g / min according to the cross-sectional area of ​​the exhaust port.

[0032] Assuming the pressure at time t1 is P1 and the pressure at time t2 is P2, then Δt1 = t2 - t1 and ΔP1 = P2 - P1.

[0033] Overall, the pressure in stage M1 rose steadily with a low steam rate; please refer to [link / reference needed] for details. Figure 2 and Figure 3 The diagram shows the dynamic changes in pressure and steam rate inside a rice cooker over cooking time, using the example of steaming Northeast pearl rice in a rice cooker. Figure 2 The curve showing the change in Pt. Figure 3 The curves represent the changes in temperature and steam rate. The horizontal axis represents cooking time t (in minutes), and the vertical axis represents the pressure inside the pot P (in kPa) and the steam rate V (in g / min), respectively. It can be seen that during the preheating and water absorption stage, which corresponds to the 0-3 minute period, the Pt curve shows a smooth and slow upward trend, with the pressure increasing from 0 kPa to 5 kPa at a rate of approximately 0.6 kPa / s. The Vt curve is close to the horizontal axis, with the steam rate slowly increasing from 0 to 0.5 g / min, maintaining a low rate overall. This is consistent with the characteristics of "slow pressure increase and low steam rate" in this stage. At this time, the heating power W = 300 W, maintained for 3 minutes, P slowly increases (at a rate of 0.6 kPa / s), and V ≈ 0.

[0034] The characteristics of M2 in the gelatinization transition stage are set as follows: The pressure standard deviation (i.e. pressure fluctuation) σP satisfies the pressure standard deviation threshold, and the steam rate change rate ΔV2 / Δt2 satisfies the first steam rate change rate threshold.

[0035] The pressure standard deviation threshold is ≥0.8 kPa, i.e., σP≥0.8 kPa. The time window Δt2 can range from 3 to 5 seconds, and the pressure change rate can be defined as having at least 3 consecutive positive and negative changes within the time window Δt2, reflecting the characteristic state of large pressure fluctuations in this stage. For example, according to the time sequence, the pressures corresponding to times t3, t4, t5, t6, t7, and t8 are P3, P4, P5, P6, P7, and P8, respectively. Then, ΔP2 / Δt2 = (P4-P3) / (t4-t3); ΔP3 / Δt3 = (P6-P5) / (t5-t5); ΔP4 / Δt4 = (P8-P7) / (t8-t7). When P2 / Δt2>0, then ΔP3 / Δt3<0; ΔP4 / Δt4>0, i.e., there are 3 consecutive positive and negative changes.

[0036] The first threshold for the rate of change of steam rate is ≥0.8 g / min², that is, the rate of change of steam rate ΔV² / Δt² ≥0.8 g / min².

[0037] Overall, stage M2 experiences large pressure fluctuations and a sharp increase in steam rate. Please refer to [further details]. Figure 2 and Figure 3 During the gelatinization transition stage, which corresponds to a time period of 3-5 minutes, the Pt curve exhibits a sawtooth-like pattern of violent fluctuations, with the pressure repeatedly changing within the 5-10 kPa range. The pressure standard deviation σP ≈ 1.0 kPa. The Vt curve shows a steep upward trend, with the steam rate rapidly increasing from 0.5 g / min to 5.0 g / min, a change rate ≥ 0.8 g / min². This aligns with the characteristics of this stage: "large pressure fluctuations and a steep increase in steam rate." At this point, σP ≈ 1.0 kPa, and V rapidly increases from 0.5 g / min to 5.0 g / min. The system automatically adjusts W from 600 W to 400 W.

[0038] The characteristic settings for M3 in the gelation and expansion stage are as follows: The pressure P is greater than the first pressure threshold, and the pressure change ΔP satisfies the first pressure change threshold. Furthermore, within a preset time period, the steam rate V satisfies the second steam rate threshold (e.g., preset time period Δt10 ≥ 30 seconds).

[0039] The first pressure change threshold is within the range of P ± 0.5 kPa, meaning that the pressure P fluctuates within the range of ± 0.5 kPa; the second steam rate threshold is V (peak value) ± 10%, meaning that the steam rate V belongs to the range of V (peak value) ± 10%.

[0040] Overall, the pressure in stage M3 remains stable at a high level, and the steam rate also remains relatively stable at a high level. Please refer to [further details]. Figure 2 and Figure 3During the gelation and expansion stage, which corresponds to a time period of 5-7.5 min, the Pt curve shows a high and stable state, with the pressure fluctuating slightly within the range of 18 kPa ± 0.5 kPa. Simultaneously, the Vt curve forms a high and stable plateau, with the steam rate maintained within the range of 8.0 g / min ± 10%, which is consistent with the characteristics of "high and stable pressure and steam rate" in this stage. At this time, the P plateau is 18 kPa ± 0.5, and V remains at 8.0 g / min, maintaining Δt = 150 seconds.

[0041] The characteristic settings for M4 during the rice cooking stage are as follows: Within a first preset time period (e.g., 30s), the pressure P is greater than the second pressure threshold and less than the first pressure threshold, the pressure change ΔP satisfies the second pressure change threshold, and the pressure change rate satisfies the second pressure change rate threshold; and within a second preset time period (e.g., ≥30s), the steam rate change rate ΔV2 / Δt2 satisfies the second steam rate change rate threshold.

[0042] The second pressure change threshold is within the range of P ± 0.5 kPa, meaning the pressure P fluctuates within the range of ± 0.5 kPa; the second pressure change rate threshold is greater than or equal to -0.1 kPa / s and less than 0.1 kPa / s, meaning ΔP1 / Δt1 belongs to the range of -0.1~0.1 kPa / s; the second steam rate change rate threshold is ≥ 0.5 g / min², meaning ΔV3 / Δt10 ≤ 2.0 g / min, lasting for at least 30 s.

[0043] Overall, the pressure in stage M4 remains high while the steam rate gradually decreases. Please refer to [further details]. Figure 2 and Figure 3 During the simmering and cooking stage of the rice, which corresponds to the time period of 7.5-12.5 min, the Pt curve shows a smooth and slow downward trend, with the pressure decreasing uniformly from 18 kPa to 15 kPa; the Vt curve shows a uniform downward trend, with the steam rate decreasing from 8.0 g / min to 0 at a rate of 0.6 g / min², which is consistent with the characteristics of "slow pressure decrease and continuous steam rate decrease" in this stage. At this time, P stabilizes at 15 kPa, and V continues to decrease at a rate of 0.6 g / min², maintaining Δt = 300 seconds.

[0044] The characteristic settings for M5 during the heat preservation stage are as follows: The temperature change meets the temperature threshold, and the heating power meets the power threshold; specifically, the temperature threshold is 0. Please refer to the following: Figure 2 and Figure 3 The heat preservation stage corresponds to a time period of 12.5-18 minutes: the Pt curve drops rapidly and vertically to 0 kPa and remains there; the Vt curve remains unchanged at 0 g / min, which is consistent with the characteristics of "no pressure and no steam generation" in this stage. At this time, W=50W and the temperature is constant at 70°C.

[0045] It should be noted that the aforementioned preset duration, first preset duration, and second preset duration are time thresholds.

[0046] By comparing the working status parameters with preset feature thresholds, the current operating stage can be determined.

[0047] S103: Determine the posterior probability of the quasi-operation stage based on the working state parameters of the rice cooker; the posterior probability of the quasi-operation stage characterizes the probability that the current operating stage of the rice cooker is the quasi-operation stage.

[0048] In one feasible implementation, determining the posterior probability of the quasi-operation stage based on the rice cooker's operating state parameters includes: performing feature processing on the rice cooker's operating state parameters to form a feature parameter set; the feature parameter set includes multiple feature parameters used to measure the current operating stage of the rice cooker; for each operating stage of the rice cooker, determining the likelihood function of the operating stage based on the feature parameter set, and obtaining the prior probability of the operating stage; the prior probability of the operating stage represents the probability that the current operating stage is the operating stage under historical cognitive conditions; the likelihood function of the operating stage represents the probability that the feature parameter set is observed under the operating stage; and determining the posterior probability of the quasi-operation stage based on the prior probability and likelihood function of each operating stage.

[0049] In one feasible implementation, determining the posterior probability of the quasi-operation stage based on the prior probability and likelihood function of each of the operation stages includes: for each operation stage of the rice cooker, determining the joint probability of the operation stage by multiplying the likelihood function and prior probability of the operation stage; the joint probability characterizes the probability that the current operation stage is the operation stage and that the observation of the feature parameter set occurs simultaneously; determining the joint probability of the quasi-operation stage from the joint probabilities of each of the operation stages; and normalizing the joint probability of the quasi-operation stage based on the sum of the joint probabilities of multiple operation stages to obtain the posterior probability of the quasi-operation stage.

[0050] Specifically, the operating state parameters include operating time t, pressure P, steam rate V, temperature T, and heating power W, and can also be extended to include lid temperature, exhaust port humidity, and acoustic boiling signal (micro-vibration of the pot body). By performing feature processing on the parameters t, P, V, T, and W, such as solving for the first-order rate of change of V, and calculating ΔP and σP based on t and P, the feature parameter set X={P,ΔP,σP,V,dV / dt,T,W} can be obtained. For each operating stage i, the likelihood function is expressed as P(X|stage_i); the prior probability is expressed as P(stage_i); the joint probability is expressed as P(X|stage_i)×P(stage_i); and the posterior probability P(stage_i|X) can be determined based on the following formula: P(stage_i|X)=[P(X|stage_i)×P(stage_i)] / Σ_j[P(X|stage_j)×P(stage_j)] Where j represents the set of all candidate stages {water absorption, gelatinization, expansion, simmering, heat preservation}; Σ_j[…] represents the normalization term, which guarantees that the sum of probabilities is 1.

[0051] The likelihood function P(X|stage_i) represents the probability of observing the feature parameter set X given that the cooking stage is i. Assumptions: Each feature parameter is an independent normal distribution (adapting to the distribution characteristics of sensor-collected data, with strong engineering feasibility). Through a large number of cooking experiments, the mean μ_ik and standard deviation σ_ik of each feature parameter at each stage i are obtained, where k is the feature parameter index, corresponding to P, ΔP, σP, V, dV / dt, T, and W. Therefore, the likelihood function can be expressed as the following formula:

[0052] Where X_k represents the actual observed value of the k-th parameter in the feature parameter set X; μ_ik represents the experimental mean of the k-th feature parameter in the i-th stage; and σ_ik represents the experimental standard deviation of the k-th feature parameter in the i-th stage. This indicates a series multiplication of the probability density functions of the seven feature parameters. The following example uses steamed Northeast pearl rice, specifically during the gelatinization transition stage (stage i=2), to illustrate the likelihood function calculation: First, determine the characteristic mean / standard deviation of the gelatinization transition stage. k1(P): Mean 7.5 kPa, Standard Deviation 1.2 kPa k2(ΔP): Mean 0 kPa, Standard Deviation 0.8 kPa k3(σP): Mean 1.0 kPa, Standard Deviation 0.2 kPa k4(V): Mean 2.75 g / min, Standard deviation 1.1 g / min k5(dV / dt): Mean 2.25 g / min², Standard deviation 0.5 g / min² k6(T): Mean 70℃, Standard Deviation 3℃ k7(W): Mean 500W, Standard Deviation 50W Next, obtain the feature parameter set X and the actual observed values ​​(at a certain sampling time during the gelatinization transition stage). X={P=8.0,ΔP=+0.5,σP=1.1,V=3.0,dV / dt=2.5,T=72,W=480} Then, the probability density function (PDF) of each feature parameter is calculated. Taking k1=P as an example, the calculation process is as follows: f(P) = ≈1 / 3×exp{-0.25 / 2.88}≈0.333×0.917≈0.305 The results of PDF calculations for the remaining parameters are as follows: f(ΔP)=0.468; f(σP)=0.804; f(V)=0.352; f(dV / dt)=0.352; f(T)=0.265; f(W)=0.0073 Step 4: Multiply the results to obtain the likelihood function value. P(X|stage 2) = 0.305 × 0.468 × 0.804 × 0.352 × 0.352 × 0.265 × 0.0073 ≈ 2.75 × 10^-5 III. Key Supplementary Explanations 1. The absolute value of the likelihood function has no practical meaning. Its core purpose is to compare the relative values ​​between different stages. After multiplying it with the prior probability P(stage i) of each stage and normalizing it, the posterior probability can be obtained. 2. The prior probability P(stage i) is an experimental statistical empirical value (e.g., P(stage 1) = 0.3, P(stage 2) = 0.25), which does not require complex calculation and can be preset in the rice cooker control unit; 3. The entire calculation process uses a simplified engineering algorithm without high-order operations, and can be executed in real time by the rice cooker MCU, meeting the timeliness requirements of dynamic control.

[0053] S104: If the posterior probability of the quasi-operation stage is not less than the preset probability, the quasi-operation stage is determined as the target operation stage.

[0054] In this embodiment of the application, the preset probability can be set to the range of 0.7 to 1.

[0055] S105: Obtain the preset control coefficient and target temperature of the target operating stage; and determine the power adjustment item based on the preset control coefficient, the temperature and the target temperature.

[0056] In one feasible implementation, the temperature in the operating status parameters includes multiple temperature values ​​within the operating time; the preset control coefficient includes a proportional coefficient, an integral coefficient, and a derivative coefficient; the proportional coefficient characterizes the response to the current error; the integral coefficient characterizes the correction term for long-term deviations; the derivative coefficient characterizes the suppression term for data fluctuations; determining the power adjustment term based on the preset control coefficient and the target temperature includes: determining the current temperature from the operating status parameters of the rice cooker; determining the temperature difference based on the target temperature of the target operating stage and the current temperature; determining a target temperature dataset from the temperatures; the target temperature dataset includes temperature values ​​within a preset operating time; determining the temperature integral term and the temperature difference change rate term within the preset operating time based on the target temperature dataset; and determining the power adjustment term based on the temperature difference, the temperature integral term, the temperature difference change rate term, the proportional coefficient, the integral coefficient, and the derivative coefficient.

[0057] Each operating stage i corresponds to a pre-set control coefficient, such as the proportional coefficient Kp(i), integral coefficient Ki(i), and derivative coefficient Kd(i). Different Kp, Ki, and Kd are set for different stages. For example, a lower Kp is used in the rice-cooking stage to prevent overshoot. If the current temperature is T(t) and the target temperature of operating stage i is T_set(i), then the temperature difference e(t) = T_set(i) - T(t); the temperature integral term is ∫e(t)dt; the temperature difference change rate term is de(t) / dt; and the power adjustment term ΔW = Kp(i)×e(t) + Ki(i)×∫e(t)dt + Kd(i)×de(t) / dt. In this way, the heating power of the current operating stage can be dynamically adjusted. For example, if it is determined that the current operating stage is the rice-cooking stage and V(t) drops too quickly, W(t) can be reduced to extend the holding time and prevent undercooking.

[0058] The holding time refers to the time the system maintains the heating or heat preservation conditions of a certain stage after recognizing that it has entered that stage, measured in seconds per minute. For example, a holding time of 5 minutes for the rice cooking stage means that after entering the rice cooking stage, the current heating mode will be maintained for 5 minutes before entering the next stage.

[0059] S106: Adjust the heating power based on the power adjustment item, so as to control the operation of the rice cooker using the adjusted heating power.

[0060] In one feasible implementation, after adjusting the heating power based on the power adjustment item in step S106, the method further includes: acquiring a current control curve and a historical control curve; the current control curve represents the relationship between the current running time of the rice cooker and the change in the current heating power; the historical control curve represents the relationship between the historical running time and the historical heating power of the rice cooker; the current heating power is the heating power adjusted based on the power adjustment item; determining whether there is a difference between the current control curve and the historical control curve; if so, determining the difference item between the current control curve and the historical control curve; if not, controlling the rice cooker to work based on the current control curve; adjusting the current control curve based on the difference item to obtain a target control curve; controlling the rice cooker to work based on the target control curve. By comparing the current control curve with the historical control curve, if there is a difference, the heating power curve can be corrected, that is, the holding time and / or heating power can be corrected, thereby improving the accuracy of the control curve. By saving historical cooking data for the rice types frequently used by the user (set via APP or rice type button), the current control curve can be fine-tuned using the historical pressure / steam feedback trend inside the pot. For example, historical data shows that a certain type of rice has the best texture during the 90-second plateau phase of the rice cooking process, while the default curve is 120 seconds. Therefore, the system will adjust the cooking time of that rice type from 120 seconds to 90 seconds the next time it is cooked, and simultaneously reduce the slope of the cooking curve (W) to achieve a smoother finish. This combination of real-time updates and historical control curve learning further improves the accuracy of rice cooker cooking control.

[0061] Generally speaking, the control unit of a rice cooker has a built-in default curve. When cooking, the historical curve of the rice variety is called up and the default curve is corrected (such as changing the holding time of the rice cooking stage from 120 seconds to 90 seconds). The correction result is saved and can be directly called up when cooking again without having to recalculate each time.

[0062] Through steps S101-S106 above, the current cooking stage can be determined by the dynamic trend of changes, and the control strategy can be automatically switched. Specifically, this can be achieved by dynamically adjusting the power adjustment item. For example, in the early stage of gelatinization, if the steam rate V rises rapidly, the heating power can be adjusted to enter the "constant temperature and variable pressure range" to slow down the expansion. The "constant temperature and variable pressure range" refers to reducing the heating power to the minimum value required to maintain the current temperature (such as 20%~40% of the rated power) to keep the temperature constant, while allowing the pressure to drop slowly to prevent the food from expanding excessively. In the rice cooking stage, if the high-level plateau P is maintained for too long, the heating power can be adjusted to enter the heat preservation mode in advance to avoid overcooking. The high-level plateau P being maintained for too long can be specifically defined as P being in the plateau range (fluctuating within ±0.3 kPa) for a duration ≥150 seconds (which can be adjusted to 150~180 seconds depending on the type of rice). This is considered too long, and the heat preservation mode is entered in advance to avoid overcooking.

[0063] For example, determining whether there is a difference between the current control curve and the historical control curve can be done by comparing each operating stage one by one. For instance, the preheating and water absorption stage in the current control curve can be compared with the preheating and water absorption stage in the historical control curve. The same cooking object (same rice type, same water-to-rice ratio) and the same cooking mode can be used as the benchmark (the historical control curve is the optimal cooking curve under this benchmark, which is preset in the control unit). If there is a difference in either of the two dimensions, it is determined that there is a difference in that stage.

[0064] Dimension 1: Comparison of retention time in each stage The duration of the same stage in the current control curve is directly compared with that in the historical control curve, and the judgment threshold is ±10% (which can be adjusted according to the rice type). •Example: The gelation and expansion phase in the historical curve lasted for 150 seconds, while the current curve lasts for 120 seconds, a deviation of 20%, which exceeds the threshold. Therefore, it is determined that there is a difference in this dimension. • Indifference determination: If the duration deviation between the historical and current curves in the same stage is ≤10%, the duration dimension is considered to be consistent. Dimension 2: Comparison of time-power correspondence within a phase (covering power values ​​at the same moment, and not limited to the same moment). Using the time points within a historical control curve as a benchmark, compare the heating power values ​​of the current curve at the same time and stage, and simultaneously verify the consistency of the power change trend within the stage. Specific rules are as follows: 1. Simultaneous power value comparison: Within a period, the power values ​​at the same time are compared at a sampling frequency of 1 second / time. The deviation threshold for a single point is ±50W, and only when the deviation of 3 or more consecutive sampling points exceeds the threshold is it determined that there is a difference in the dimension of that point (to avoid misjudgment caused by instantaneous noise of the sensor). 2. Power change trend comparison: Verify whether the overall power change trend (rising / falling / stable) is consistent within the same period. If the trends are opposite, the difference is determined (e.g., the power in the historical curve during the gelatinization transition period is "rising → falling", while the current curve is continuously rising, directly determining the trend difference). • Example: In the historical curve of the rice cooking stage (180s), the power decreased from 400W to 300W at a constant rate in the first 90s and remained stable in the next 90s; in the current curve, the power decreased from 400W to 350W in the first 90s of the same stage, with a deviation of more than 50W at multiple consecutive sampling points, and the trend was "gradual decrease → increase", which means that there is a difference in this dimension.

[0065] Therefore, if there is a difference in any of the above dimensions in one or more stages, it is determined that "there is a difference between the current control curve and the historical control curve"; only when there is no difference in the two core dimensions of all stages is it determined that there is no difference in the curve, and the current curve is directly used for control.

[0066] If there is a difference in the judgment curve, the difference item is a combination of a specific stage and a specific difference dimension. For example: "gelatinization and expansion stage (maintaining a deviation of 20% in duration), rice cooking stage (power value deviation exceeding the threshold at the same moment within the stage)".

[0067] This comparison method is a lightweight algorithm. The control unit only needs to call the stage thresholds (holding time and heating power value at each time node) of the historical curve and compare them with the real-time data of the current curve. No complex calculations are required. It can be executed in real time by the MCU, which is in line with the hardware computing capabilities of the rice cooker.

[0068] Specifically, determining whether there is a difference between the current control curve and the historical control curve can be described as follows: For each operating stage, determine the deviation between the holding time of the operating stage in the current control curve and the holding time in the historical control curve; when the holding time deviation is less than or equal to a preset time deviation, determine whether the heating power of the operating stage in the current control curve and the historical control curve is inconsistent; subsequently, if yes, determine the difference between the current control curve and the historical control curve; if no, control the rice cooker to work based on the current control curve.

[0069] The step of determining whether the heating power of the current control curve and the historical control curve is inconsistent during the operation phase can specifically include: determining whether there is a power difference between the heating power of a consecutive preset number of sampling points in the current control curve and the historical control curve that exceeds a preset power threshold during the operation phase; if yes, then a first determination result is generated; the first determination result indicates that the heating power of the current control curve and the historical control curve is inconsistent during the operation phase; if no, then determining whether the changing trend of the heating power of the current control curve and the historical control curve is consistent during the operation phase; if yes, then a second determination result is generated; if no, then the first determination result is generated; the second determination result indicates that the heating power of the current control curve and the historical control curve is consistent during the operation phase. Optionally, the preset number can be an integer greater than or equal to 3.

[0070] In one feasible implementation, the method further includes: determining a hysteresis parameter when the current operating stage of the rice cooker is a gelatinization transition stage or a gelation expansion stage, and the stage switching conditions are met; the hysteresis parameter characterizes the parameter for delaying the switching of the current operating stage; adjusting the current control curve based on the hysteresis parameter; the current control curve characterizes the relationship between the current operating time and the current heating power of the rice cooker; and controlling the rice cooker to operate based on the adjusted current control curve.

[0071] In one feasible implementation, the hysteresis parameter includes any one or more of the following: the extension of the holding time during the current operating phase, the rate of change of pressure not exceeding a first threshold, and the rate of change of steam rate not exceeding a second threshold.

[0072] For example, when switching from the gelatinization transition stage to the gelatinization expansion stage, or from the gelatinization expansion stage to the rice cooking stage, a delay of 2-5 seconds can be made. Alternatively, within a preset time (e.g., 5 seconds), the fluctuations in pressure (ΔP) and steam rate (ΔV) can be kept below the set thresholds (pressure change rate ΔP ≤ 0.3 kPa, steam rate change rate ΔV ≤ 1 g / min). This allows for adjustment of the current control curve before switching to the next stage. Correspondingly, the preset control coefficient, heating power, and holding time will all change. Setting a hysteresis parameter at a specific stage allows for early stage switching based on trend prediction, preventing misjudgments due to instantaneous fluctuations and preventing overcooking.

[0073] In this embodiment, anomaly warning and fault-tolerant processing steps can also be set. Specifically, the method further includes: when each parameter in the working state parameters meets the warning parameter conditions, corresponding warning information is generated and the system switches to a safe and conservative control strategy. For example, if P undergoes an abnormal change or V is 0 in its expected stage, it indicates steam leakage, heating abnormality, etc., and the system can automatically switch to a safe and conservative control strategy to avoid food damage.

[0074] As can be seen from the above technical solutions of the embodiments of this application, the embodiments of this application achieve a staged, closed-loop optimized intelligent cooking method by dynamically identifying the stages of the rice cooker's cooking process and intelligently adjusting the heating control parameters accordingly. Through the joint judgment of real-time physical signals, it can achieve precise cooking for different types of rice and different water-to-rice ratios, improving the adaptability of different types of rice under different conditions and the quality of cooked rice. Because it can automatically identify and control in stages, it reduces human intervention and improves the consistency of rice texture; compared with a single temperature control scheme, it can more accurately identify the gelatinization point and the completion point of steaming; it enhances the user experience, has a high degree of intelligence, and good energy-saving effect.

[0075] On the other hand, a dynamic control system for a rice cooker is provided, comprising a pot body, a temperature sensor, a pressure sensor, a steam rate sensor, a control unit, and a heating device; the temperature sensor is located at the bottom of the pot body and is used to collect the bottom temperature of the pot body; the pressure sensor is used to collect the internal pressure of the pot body; the steam rate sensor is used to collect the steam rate; the heating device is used to heat the pot body; the control unit is electrically connected to the temperature sensor, the pressure sensor, the steam rate sensor, and the heating device respectively, and is used to execute the above-described dynamic control method for the rice cooker.

[0076] The heating device is an adjustable heating device (supporting variable power heating), which is specifically set at the heating plate or annular heating belt at the bottom of the pot. The power can be adjusted from 0% to 100% through PWM modulation or multi-level power relays. The drive circuit is connected to the MCU.

[0077] On the other hand, a smart home appliance is provided, which is a rice cooker, and the rice cooker is equipped with the aforementioned dynamic control system for rice cookers.

[0078] In this embodiment, the dynamic control system of the rice cooker can be specifically set in the smart rice cooker. The smart rice cooker is equipped with a smart voice control module, which includes a controller, a voice receiving module, and a voice parsing module. The voice receiving module receives user commands, and the voice parsing module parses the commands. Based on the parsed commands, the controller, smart rice cooker, and touch display device execute corresponding operations, thereby realizing intelligent control of the smart rice cooker and touch display device and improving the user's experience of using smart appliances.

[0079] It should be noted that the order of the embodiments described above is merely for descriptive purposes and does not represent the superiority or inferiority of the embodiments. Furthermore, specific embodiments have been described above. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps described in the claims can be performed in a different order than that shown in the embodiments and still achieve the desired result. Additionally, the processes depicted in the drawings do not necessarily require a specific or sequential order to achieve the desired result. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0080] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, the apparatus embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions of the method embodiments.

[0081] Those skilled in the art will understand that all or part of the steps of the above embodiments can be implemented by hardware or by a program instructing related hardware. The program can be stored in a computer-readable storage medium, such as a read-only memory, a disk, or an optical disk.

[0082] The above description is only a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A dynamic control method for an electric rice cooker, characterized in that, The method includes: The system acquires the operating status parameters and preset characteristic thresholds of the rice cooker; the operating status parameters include running time, pressure, steam rate, temperature, and heating power; the preset characteristic thresholds are used to measure the operating stage of the rice cooker. The current quasi-operation stage of the rice cooker is determined based on the rice cooker's operating status parameters and the preset feature threshold. The posterior probability of the quasi-operation stage is determined based on the operating state parameters of the rice cooker; the posterior probability of the quasi-operation stage represents the probability that the current operating stage of the rice cooker is the quasi-operation stage. If the posterior probability of the quasi-operation phase is not less than the preset probability, the quasi-operation phase is determined as the target operation phase. Obtain the preset control coefficient and target temperature for the target operating phase; and determine the power adjustment term based on the preset control coefficient, the temperature, and the target temperature; The heating power is adjusted based on the power adjustment item so as to control the operation of the rice cooker using the adjusted heating power.

2. The dynamic control method according to claim 1, characterized in that, Determining the posterior probability of the quasi-operation phase based on the rice cooker's operating state parameters includes: The operating status parameters of the rice cooker are subjected to feature processing to form a feature parameter set; the feature parameter set includes multiple feature parameters used to measure the current operating stage of the rice cooker; For each operating stage of the rice cooker, a likelihood function for the operating stage is determined based on the feature parameter set, and a prior probability for the operating stage is obtained; the prior probability of the operating stage represents the probability that the current operating stage is the operating stage under historical cognitive conditions; the likelihood function of the operating stage represents the probability that the feature parameter set is observed under the operating stage. The posterior probability of the quasi-operational stage is determined based on the prior probability and likelihood function of each of the aforementioned operational stages.

3. The dynamic control method according to claim 2, characterized in that, Determining the posterior probability of the quasi-operational stage based on the prior probability and likelihood function of each of the aforementioned operational stages includes: For each operating stage of the rice cooker, the product of the likelihood function and the prior probability of the operating stage is determined as the joint probability of the operating stage; the joint probability represents the probability that the current operating stage is the operating stage and that the observed feature parameter set occurs simultaneously. The joint probability of the quasi-operational stage is determined from the joint probability of each of the aforementioned operational stages; Based on the sum of the joint probabilities of multiple operational phases, the joint probability of the quasi-operational phase is normalized to obtain the posterior probability of the quasi-operational phase.

4. The dynamic control method according to claim 1, characterized in that, The temperature in the operating status parameters includes multiple temperature values ​​within the operating time; the preset control coefficients include proportional coefficients, integral coefficients, and derivative coefficients; the proportional coefficients characterize the response to the current error; The integral coefficient represents the correction term for long-term deviation; Differential coefficients characterize the suppression terms of data fluctuations; The determination of the power adjustment term based on the preset control coefficient and the target temperature includes: The current temperature is determined from the operating status parameters of the rice cooker; The temperature difference is determined based on the target temperature of the target operating phase and the current temperature. A target temperature dataset is determined from the stated temperatures; the target temperature dataset includes temperature values ​​within a preset running time. Based on the target temperature dataset, determine the temperature integral term and the temperature difference change rate term within the preset operating time. The power adjustment term is determined based on the temperature difference, the temperature integral term, the temperature difference change rate term, the proportional coefficient, the integral coefficient, and the derivative coefficient.

5. The dynamic control method according to any one of claims 1-4, characterized in that, The method further includes: Obtain the current control curve and the historical control curve; the current control curve represents the relationship between the current running time and the current heating power of the rice cooker; the historical control curve represents the relationship between the historical running time and the historical heating power of the rice cooker; the current heating power is the heating power adjusted based on the power adjustment item; Determine whether there is a difference between the current control curve and the historical control curve. If yes, determine the difference between the current control curve and the historical control curve; otherwise, control the rice cooker to work based on the current control curve. The current control curve is adjusted based on the difference terms to obtain the target control curve; The rice cooker is controlled based on the target control curve.

6. The dynamic control method according to any one of claims 1-4, characterized in that, The operation stages of the rice cooker include a preheating and water absorption stage, a gelatinization transition stage, a gelatinization and expansion stage, a rice cooking stage, and a heat preservation stage; the method further includes: If the current operating stage of the rice cooker is the gelatinization transition stage or the gelation expansion stage, and the stage switching conditions are met, a hysteresis parameter is determined; the hysteresis parameter represents the parameter that delays the switching of the current operating stage. The current control curve is adjusted based on the hysteresis parameter; the current control curve represents the relationship between the current running time and the current heating power of the rice cooker. The rice cooker is controlled based on the adjusted current control curve.

7. The dynamic control method according to claim 6, characterized in that, The hysteresis parameters include any one or more of the following: the extension of the holding time during the current operating phase, the rate of change of pressure not exceeding a first threshold, and the rate of change of steam rate not exceeding a second threshold.

8. The dynamic control method according to claim 1, characterized in that, The preset feature thresholds include a first type of state threshold and a second type of state threshold; determining the current quasi-operation stage of the rice cooker based on the rice cooker's operating state parameters and the preset feature thresholds includes: A first judgment result is determined based on the running time, the pressure, and the first type of state threshold; The second judgment result is determined based on the running time, the steam rate, and the second type of state threshold; The current operating stage of the rice cooker, characterized by the first judgment result and the second judgment result, is determined as the quasi-operating stage.

9. A dynamic control system for an electric rice cooker, characterized in that, It includes the pot body, temperature sensor, pressure sensor, steam rate sensor, control unit, and heating device; The temperature sensor is located at the bottom of the pot body and is used to collect the bottom temperature of the pot body; The pressure sensor is used to collect the internal pressure of the pot body; The steam rate sensor is used to collect steam rate data. The heating device is used to heat the pot body; The control unit is electrically connected to the temperature sensor, the pressure sensor, the steam rate sensor and the heating device respectively, and is used to execute the dynamic control method of the rice cooker as described in any one of claims 1-8.

10. A smart home appliance, characterized in that, The smart home appliance is a rice cooker, and the rice cooker is equipped with a dynamic control system as described in claim 9.

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