Intelligent kitchen appliance control method and system based on ultrasonic liquid level detection and medium

Abstract

The invention relates to an intelligent kitchen appliance control method and system based on ultrasonic liquid level detection and a medium, and relates to the technical field of intelligent kitchens. Ultrasonic waves are transmitted to a cookware area on a cooker, and echo signals are received; extracting peak voltage and rise time in the echo signal; the rise time is the time required for transmitting the ultrasonic wave until the echo signal reaches the target intensity; based on the peak voltage and the rise time, whether the cooking state in the pot is a dry burning state or not is evaluated; and the working state of the range hood or the cooker is adjusted based on the cooking state, the problems that safety response lags behind, and autonomous judgment and linkage control capacity for the cooking process is lacked are solved, real-time accurate recognition of the state of the cooker and active prevention and control of risks are achieved, and therefore kitchen safety and use experience are comprehensively improved.

Description

Technical Field

[0001] This application relates to the field of smart kitchen technology, and in particular to a smart control method, system and medium for kitchen appliances based on ultrasonic liquid level detection. Background Technology

[0002] As core appliances in modern kitchens, range hoods and cooktops are still in the early stages of intelligent development. Currently, the intelligent functions of mainstream kitchen appliances mainly focus on Wi-Fi network control, contactless gesture switches, and basic air quality monitoring, without exploring proactive safety protection mechanisms during the cooking process.

[0003] In practical use, users often become distracted, causing the liquid in the pot to boil dry, potentially producing a large amount of smoke and even posing a fire hazard. Existing products rely heavily on temperature sensors or smoke detectors to sense the state inside the pot, but these technologies have significant time lags, making it difficult to provide timely warnings or interventions when risks first appear. Furthermore, even if the system detects an anomaly, users usually still need to manually adjust the fan speed or turn off the device, failing to achieve true "autonomous driving" in the cooking world.

[0004] There is currently no effective solution to the problem of insufficient intelligence in kitchen appliances in related technologies. Summary of the Invention

[0005] This embodiment provides a method, system, and medium for intelligent control of kitchen appliances based on ultrasonic liquid level detection, in order to solve the problem of insufficient intelligence in kitchen appliances in related technologies.

[0006] In a first aspect, this embodiment provides a smart control method for kitchen appliances based on ultrasonic liquid level detection, the method comprising:

[0007] It emits ultrasonic waves toward the cookware area on the stove and receives the echo signals;

[0008] Extract the peak voltage and rise time from the echo signal; the rise time is the time required for the echo signal to reach the target intensity after the ultrasonic wave is emitted.

[0009] The cooking state of the cookware is evaluated based on the peak voltage and the rise time, the cooking state including at least the dry-burning state;

[0010] If the cookware is in a dry-burning state, adjust the working status of the range hood or the stove.

[0011] In some embodiments, the cooking state of the cookware is evaluated based on the peak voltage and the rise time, including:

[0012] Determine whether the peak voltage is greater than a preset voltage threshold and whether the rise time is less than a preset time threshold;

[0013] If the peak voltage is greater than the voltage threshold and the rise time is less than the time threshold, then the cookware is determined to be in a state of being burned dry.

[0014] If the peak voltage is less than the voltage threshold, or the rise time is greater than the time threshold, then the cookware is determined to be in a normal state.

[0015] In some of these embodiments, the voltage threshold is calculated based on a preset mutation coefficient and the obtained calibration intensity;

[0016] The calibrated intensity is obtained from the echo intensity reflected by the liquid surface in the cookware under normal conditions.

[0017] In some embodiments, if the cookware is in a dry-burning state, adjusting the operating state of the range hood or the stove includes:

[0018] If the cookware is in a dry-burning state, the range hood will sound an alarm and be set to the maximum airflow level, and will continuously monitor whether the cookware is in a dry-burning state for a preset monitoring time.

[0019] If the pot is dry when the monitoring time ends, the heat source of the stove is turned off.

[0020] If the cookware is in normal condition when the monitoring time ends, the alarm will be deactivated and the original fan speed will be restored.

[0021] In some embodiments, extracting the peak voltage and rise time from the echo signal includes:

[0022] Determine whether there is a secondary echo in the received echo signal;

[0023] If there is no secondary echo in the received echo signal, then extract the peak voltage and rise time in the current echo signal;

[0024] If a secondary echo is present in the received echo signal, the liquid level in the pot is calculated based on the time difference between the first and second echoes in the echo signal.

[0025] Based on the liquid level, the range hood or the stove is controlled to output corresponding liquid level indication information.

[0026] In some embodiments, the liquid level height in the cookware is calculated based on the time difference between the first and second echoes in the echo signal, including:

[0027] Calculate the time difference between the first echo and the second echo in the echo signal;

[0028] The temperature of the liquid inside the cookware is obtained, and the current speed of sound in the liquid is calculated based on the liquid temperature.

[0029] Based on the time difference and the speed of sound in the liquid, the liquid level in the pot is calculated.

[0030] In some embodiments, after calculating the liquid level in the cookware based on the time difference and the velocity of sound in the liquid, the method further includes:

[0031] Obtain the time information of the change in liquid level, and calculate the rate of change of liquid level based on the time information;

[0032] If the rate of change of the liquid level is greater than a preset threshold, the pot is determined to be in an overflow state.

[0033] The liquid sound velocity is corrected based on the overflow state, and the corrected liquid level height is calculated based on the corrected liquid sound velocity; or the range hood or stove is controlled to output corresponding boiling warning information based on the overflow state.

[0034] Secondly, this embodiment provides an intelligent range hood and cooktop linkage system, including a range hood, a cooktop, an ultrasonic sensor, and a temperature sensor connected to a controller; wherein the ultrasonic sensor and the temperature sensor are mounted on the range hood.

[0035] The ultrasonic sensor is used to emit and receive ultrasonic waves under the control of the controller.

[0036] The temperature sensor is used to detect the temperature of the liquid inside the cookware under the control of the controller.

[0037] The controller is configured to implement the steps of the method described in any one of the first aspects.

[0038] In some embodiments, the ultrasonic sensor is mounted at the bottom of the smoke baffle or air inlet panel of the cooking fume hood, facing the center of the cookware, with a resonant frequency of 40kHz.

[0039] Thirdly, this application also provides a computer-readable storage medium. The computer-readable storage medium stores a computer program thereon, which, when executed by a processor, implements the intelligent control method for kitchen appliances based on ultrasonic liquid level detection as described in the first aspect.

[0040] Compared with related technologies, the intelligent kitchen appliance control method, device, and computer equipment based on ultrasonic liquid level detection provided in this embodiment, by emitting ultrasonic waves to the pot area on the stove and receiving echo signals; extracting the peak voltage and rise time from the echo signals; the rise time being the time required for the echo signal to reach the target intensity after emitting the ultrasonic waves; assessing whether the cooking state inside the pot is dry-burning based on the peak voltage and rise time; and adjusting the working state of the range hood or the stove based on the cooking state, solves the problems of delayed safety response and lack of autonomous judgment and linkage control capabilities for the cooking process, achieving real-time and accurate identification of the pot status and proactive risk prevention and control, thereby comprehensively improving kitchen safety and user experience.

[0041] Details of one or more embodiments of this application are set forth in the following drawings and description to make other features, objects and advantages of this application more readily apparent. Attached Figure Description

[0042] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments of this application and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0043] Figure 1 This is a hardware structure block diagram of the terminal of the kitchen appliance intelligent control method based on ultrasonic liquid level detection in the embodiments of this application;

[0044] Figure 2 This is a flowchart illustrating the intelligent control method for kitchen appliances based on ultrasonic liquid level detection in the embodiments of this application.

[0045] Figure 3 This is a structural block diagram of the intelligent range hood and stove linkage system in the embodiments of this application;

[0046] Figure 4 This is a schematic diagram of the intelligent range hood and stove linkage system in a preferred embodiment of this application;

[0047] Figure 5 This is a flowchart illustrating the overall process of the intelligent control method for kitchen appliances based on ultrasonic liquid level detection in a preferred embodiment of this application.

[0048] Figure 6 This is a flowchart of the dry burning warning algorithm in a preferred embodiment of this application;

[0049] Figure 7 This is a flowchart of the liquid level detection algorithm in a preferred embodiment of this application.

[0050] Reference numerals: 102, processor; 104, memory; 106, transmission device; 108, input / output device; 410, range hood; 411, smoke baffle; 420, stove; 430, ultrasonic sensor; 440, temperature sensor. Detailed Implementation

[0051] To better understand the purpose, technical solution, and advantages of this application, the application is described and explained below in conjunction with the accompanying drawings and embodiments.

[0052] Unless otherwise defined, the technical or scientific terms used in this application shall have the general meaning understood by one of ordinary skill in the art to which this application pertains. Words such as “a,” “an,” “an,” “the,” “the,” and “these” used in this application do not indicate quantitative limitation and may be singular or plural. The terms “comprising,” “including,” “having,” and any variations thereof used in this application are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or device that comprises a series of steps or modules (units) is not limited to the listed steps or modules (units) but may include steps or modules (units) not listed, or may include other steps or modules (units) inherent to these processes, methods, products, or devices. Words such as “connected,” “linked,” and “coupled” used in this application are not limited to physical or mechanical connections but may include electrical connections, whether direct or indirect. “Multiple” used in this application refers to two or more. “And / or” describes the relationship between related objects, indicating that three relationships may exist; for example, “A and / or B” can represent: A alone, A and B simultaneously, and B alone. Normally, the character " / " indicates that the objects before and after it are in an "or" relationship. The terms "first," "second," "third," etc., used in this application are merely to distinguish similar objects and do not represent a specific order of objects.

[0053] The method embodiments provided in this example can be executed on a terminal, computer, or similar computing device. For example, it can run on a terminal. Figure 1 This is a hardware structure block diagram of the terminal for the intelligent control method of kitchen appliances based on ultrasonic liquid level detection in this embodiment. (See diagram for example.) Figure 1 As shown, a terminal may include one or more ( Figure 1 Only one is shown in the diagram. A processor 102 and a memory 104 for storing data are also included. The processor 102 may be, but is not limited to, a microprocessor (MCU) or a programmable logic device (FPGA). The terminal may also include a transmission device 106 for communication functions and an input / output device 108. Those skilled in the art will understand that… Figure 1The structure shown is for illustrative purposes only and does not limit the structure of the terminal described above. For example, the terminal may also include components that are larger than... Figure 1 The more or fewer components shown, or having the same Figure 1 The different configurations shown are illustrated.

[0054] The memory 104 can be used to store computer programs, such as application software programs and modules, like the computer program corresponding to the intelligent control method for kitchen appliances based on ultrasonic liquid level detection in this embodiment. The processor 102 executes various functional applications and data processing by running the computer program stored in the memory 104, thereby implementing the above-described method. The memory 104 may include high-speed random access memory, and may also include non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some instances, the memory 104 may further include memory remotely located relative to the processor 102, and these remote memories can be connected to the terminal via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0055] The transmission device 106 is used to receive or send data via a network. This network includes a wireless network provided by the terminal's communication provider. In one example, the transmission device 106 includes a Network Interface Controller (NIC), which can connect to other network devices via a base station to communicate with the Internet. In another example, the transmission device 106 can be a Radio Frequency (RF) module used for wireless communication with the Internet.

[0056] This embodiment provides a smart control method for kitchen appliances based on ultrasonic liquid level detection. Figure 2 This is a flowchart of the intelligent control method for kitchen appliances based on ultrasonic liquid level detection in this embodiment, as shown below. Figure 2 As shown, the process includes the following steps:

[0057] Step S210: Emit ultrasonic waves to the pot area on the stove and receive echo signals.

[0058] Specifically, when cooking on a stovetop, users may become distracted, causing the liquid in the pot to boil dry or overflow. This embodiment uses an ultrasonic sensor to emit ultrasonic waves and receive the corresponding echo signals to detect the state inside the pot during cooking. During ultrasonic wave emission, techniques such as Barker codes can be employed to mitigate interference and enhance the signal-to-noise ratio under complex conditions such as range hood vibration or high-temperature steam.

[0059] Step S220: Extract the peak voltage and rise time from the echo signal; the rise time is the time required for the echo signal to reach the target intensity after the ultrasonic wave is emitted.

[0060] Specifically, the received echo is converted into an electrical signal, and then undergoes a series of signal processing steps, including amplification, bandpass filtering (center frequency 40kHz, range such as 38-42kHz to eliminate ambient noise), and detection (such as envelope detection), to obtain the envelope of the echo signal. The peak voltage, i.e., the echo intensity V, is then obtained based on the envelope. p The target intensity can be set according to the required accuracy, such as 90% of the peak value. Furthermore, the rise time can be defined as the time it takes for the voltage amplitude to rise from 10% to 90%.

[0061] Step S230: Based on the peak voltage and rise time, evaluate the cooking state of the cookware, which includes at least the dry-burning state.

[0062] Specifically, when ultrasound propagates through a medium, it is reflected and transmitted at the interface between different media. The reflection coefficient R (proportional to the echo intensity) is related to the acoustic impedance of the two media. Acoustic impedance Z = ρc (ρ is the density of the medium, and c is the speed of sound, such as 340 m / s for air, 1480 m / s for water, and 1400 m / s for cooking oil at 25°C). The formula for the reflection coefficient R is:

[0063] ;

[0064] Where Z1 is the acoustic impedance of the first medium (for example, for the bottom of a pot, Z1 is the acoustic impedance of the cookware material), and Z2 is the acoustic impedance of the second medium (liquid or air).

[0065] In this embodiment, when there is liquid in the pot, Z2 is the acoustic impedance of the liquid; for example, the acoustic impedance of water is approximately 1.5 × 10⁻⁶. 6 kg / (m 2 ·s) or denoted as 1.5MRayl, the acoustic impedance of the oil is approximately 1.3×10 6 kg / (m 2 When dry-burning, Z2 is the acoustic impedance of air, approximately 400 kg / (m²·s). Since the acoustic impedance of air is much smaller than that of the cookware material, such as stainless steel (approximately 45 × 10⁻⁶),... 6 The formula shows that the reflection coefficient R is close to 1 (almost total reflection) when the pot is dry-burning. Therefore, the greater the impedance difference between the two media, the larger R is and the stronger the echo. When there is liquid, R is smaller and the echo is weaker. By monitoring the echo amplitude and rise time in real time, it is possible to determine whether the liquid in the pot has boiled dry and trigger a dry-burning warning.

[0066] Step S240: If the cookware is in a dry-burning state, adjust the working status of the range hood or stove.

[0067] Specifically, if the cookware is in a dry-burning state, the range hood and stove will be activated in a timely manner to implement a dry-burning warning plan. For example, the range hood will increase its smoke extraction power, or the stove will reduce or turn off its heat, and the range hood or stove will issue an audible and visual alarm to remind the user.

[0068] In this embodiment, ultrasonic waves are emitted towards the cookware area on the stove and the echo signal is received; the peak voltage and rise time in the echo signal are extracted; the rise time is the time required for the ultrasonic wave to reach the target intensity; based on the peak voltage and rise time, the cooking state inside the cookware is assessed to determine whether it is in a dry-burning state; the working state of the range hood or stove is adjusted based on the cooking state, which solves the problems of delayed safety response and lack of autonomous judgment and linkage control capabilities for the cooking process, and realizes real-time and accurate identification of the cookware status and proactive risk prevention and control, thereby comprehensively improving kitchen safety and user experience.

[0069] In some embodiments, step S230 above, which evaluates the cooking state of the cookware based on peak voltage and rise time, includes:

[0070] Step S231: Determine whether the peak voltage is greater than a preset voltage threshold and whether the rise time is less than a preset time threshold.

[0071] Step S232: If the peak voltage is greater than the voltage threshold and the rise time is less than the time threshold, then the cooking state of the pot is determined to be the dry-burning state.

[0072] Step S233: If the peak voltage is less than the voltage threshold or the rise time is greater than the time threshold, then the cooking state of the cookware is determined to be normal.

[0073] Specifically, the voltage threshold can be set to k times the echo intensity during normal cooking, which can be pre-calibrated. Normal cooking refers to a normal liquid level inside the pot. For example, the abrupt change coefficient k can be set to 1.8 or 2. During normal cooking, due to the presence of liquid, sound waves undergo a propagation process within the liquid, resulting in a longer rise time. In contrast, during dry cooking, sound waves are directly reflected, resulting in a shorter rise time. According to cooking test experiments, Δt = 1.2~1.8 ms when liquid is present, and Δt = 0.3~0.4 ms when dry cooking. Therefore, a time threshold can be set based on the critical rise time value from cooking test experiments, for example, 0.5 ms.

[0074] In this embodiment, the accuracy of dry burning status judgment is improved by using a two-parameter response mechanism caused by a sudden change in acoustic impedance. This solves the problem of high false alarm rate in existing technologies, making dry burning warning more reliable and providing users with a better user experience.

[0075] In some embodiments, step S240 above, if the cookware is in a dry-burning state, involves adjusting the operating state of the range hood or stove, including:

[0076] Step S241: If the cookware is in a dry-burning state, control the range hood to issue an alarm and adjust it to the maximum airflow level, and continuously monitor whether the cookware is in a dry-burning state within a preset monitoring time (e.g., 30 seconds).

[0077] Step S242: If the pot is dry when the monitoring time ends, the heat source of the stove is turned off.

[0078] Step S243: If the cookware is in normal condition when the monitoring time ends, the alarm is deactivated and the original airflow setting is restored.

[0079] Specifically, when the range hood is set to the maximum airflow level, the original airflow level is recorded. After the monitoring period, when the cookware returns to normal, the range hood can be controlled to return to the original airflow level, avoiding manual adjustment by the user.

[0080] In this embodiment, the range hood and cooktop are adjusted and automatically restored through two rounds of detection, thereby further improving their intelligence.

[0081] In some embodiments, step S220 above, extracting the peak voltage and rise time from the echo signal, includes:

[0082] Step S221: Determine whether there is a secondary echo in the received echo signal.

[0083] Step S222: If there is no secondary echo in the received echo signal, extract the peak voltage and rise time in the current echo signal.

[0084] Step S223: If a secondary echo is present in the received echo signal, the liquid level in the pot is calculated based on the time difference between the first and second echoes in the echo signal.

[0085] Step S224: Based on the liquid level, control the range hood or stove to output corresponding liquid level prompt information.

[0086] Specifically, when there is a lot of liquid in the pot, due to the significant difference in the path, two echo signals can be detected, i.e., there is a secondary echo. The path of the first echo is: ultrasonic probe → liquid surface (or bottom of the pot) → ultrasonic probe. The path of the second echo is: ultrasonic probe → liquid surface → bottom of the pot → liquid surface → ultrasonic probe. The path difference is twice the liquid level height. At this time, the liquid level height can be further calculated to achieve real-time monitoring of the liquid level. When there is little liquid in the pot, the two echo signals basically overlap, and it is determined that there is no secondary echo. This can be considered as an impending dry burning. In this case, it is not necessary to calculate the liquid level height, and the relevant steps for determining the dry burning state can be directly executed.

[0087] Changes in liquid level during cooking are difficult to detect, posing a high risk of overflowing or boiling dry. Traditional electrode sensors require contact with the liquid and are prone to contamination. In this embodiment, ultrasonic waves are used to monitor the liquid level inside the cookware in real time, achieving high-precision non-contact liquid level detection.

[0088] In other embodiments, determining whether a secondary echo exists in the received echo signal is performed simultaneously with extracting the peak voltage and rise time from the echo signal. If no secondary echo exists in the received echo signal, a low liquid level warning message is directly generated. If a secondary echo exists in the received echo signal, the liquid level in the pot is calculated based on the time difference between the first and second echoes in the echo signal.

[0089] In some embodiments, step S223 above, which calculates the liquid level height in the pot based on the time difference between the first and second echoes in the echo signal, includes:

[0090] Step S301: Calculate the time difference between the first echo and the second echo in the echo signal.

[0091] Step S302: Obtain the liquid temperature inside the pot, and calculate the current liquid sound velocity based on the liquid temperature.

[0092] Step S303: Calculate the liquid level height inside the pot based on the time difference and the liquid sound velocity.

[0093] Specifically, the propagation speed of ultrasound in oil changes significantly with increasing temperature. When the oil temperature rises from room temperature (e.g., 25°C) to the commonly used cooking temperature of 200°C, the sound velocity usually deviates, for example, by taking a typical temperature coefficient k. c =3.0 m / s / ℃, the sound velocity deviation is △c=3.0×(200-25)=525 m / s. Without compensation, the liquid level calculation error exceeds ±15 mm (accounting for 30% of the pot depth), seriously reducing the reliability of the detection.

[0094] In step S302, the current liquid temperature T inside the pot, measured by the temperature sensor, as well as the preset reference temperature T0 and the sound velocity temperature coefficient k, are acquired. real Based on the sound velocity compensation model, the compensated liquid sound velocity c(T) is calculated. The sound velocity compensation model is: c(T) = c0 + k real (T-T0).

[0095] The reference temperature T0 is preferably set to 25℃, and the sound velocity temperature coefficient k real Obtained based on prior calibration. The calibrated sound speed temperature coefficient k. realThe process is as follows: Upon initial startup, inject standard oil (such as peanut oil) to a depth of 50mm, heat to T1=50℃ and T2=150℃, measure the sound velocity as c1 and c2 respectively, and calculate the sound velocity temperature coefficient k. real =(c2-c1) / (T2-T1).

[0096] Calculate the dynamic liquid level height h based on the compensated liquid sound velocity c(T):

[0097] ;

[0098] Where Δτ is the time difference between the first echo and the second echo.

[0099] In this embodiment, a dynamic sound velocity compensation model (c varies with oil temperature) is proposed for the kitchen environment. This solves the problem that the existing ultrasonic thickness measurement formula does not consider the influence of medium temperature changes and is very inaccurate in cases with thin liquid surfaces such as kitchen cookware and large temperature variations, thereby improving the reliability of smart kitchen appliances.

[0100] In some embodiments, after calculating the liquid level height in the pot based on the time difference and the speed of sound in the liquid, step S303 further includes:

[0101] Step S304: Obtain the time information of the change in liquid level height, and calculate the rate of change of liquid level height based on the time information.

[0102] Step S305: If the rate of change of liquid level is greater than the preset change threshold, for example, dh / dt > 10 mm / s, where h is the liquid level and t is the time information, then the pot is determined to be in an overflow state.

[0103] Step S306: Based on the overflow status, control the range hood or stove to output the corresponding boiling warning information, and increase the range hood's airflow level or turn off the stove's heat source.

[0104] In this embodiment, the boiling foam of the liquid causes the liquid level to rise, posing a risk of overflow. The range hood or stove is activated in a timely manner by calculating dh / dt.

[0105] In some embodiments, step S307 is further included, which involves further correcting the liquid sound velocity based on the overflow state: c 修正 =c(T)×(1+0.02e -0.5t The corrected speed of sound c 修正 This is used to replace c(T) in liquid level calculation to obtain the corrected liquid level height h. 修正 Based on the corrected liquid level height h 修正 Control the range hood by adjusting the airflow level or the stove by adjusting the heat level.

[0106] In this embodiment, the liquid sound velocity is corrected for boiling conditions to obtain a liquid level height that matches the actual situation, so as to accurately link the range hood and stove for corresponding adjustments and improve the reliability of the intelligent system.

[0107] This embodiment provides an intelligent range hood and stove linkage system. Figure 3 This is a structural block diagram of the intelligent range hood and stove linkage system in this embodiment, as shown below. Figure 3 As shown, the intelligent range hood and cooktop linkage system includes a range hood, a cooktop, an ultrasonic sensor, and a temperature sensor connected to the controller; the ultrasonic sensor and the temperature sensor are installed on the range hood.

[0108] An ultrasonic sensor is used to emit and receive ultrasonic waves under the control of a controller. Specifically, the ultrasonic sensor includes an ultrasonic transmitter and an ultrasonic receiver. The ultrasonic transmitter is installed at the bottom of the range hood's baffle or air inlet panel to emit ultrasonic waves toward the center of the cookware, at a distance of 300-700mm from the bottom of the cookware, with a resonant frequency of 40kHz±1%. The ultrasonic receiver is arranged adjacent to the transmitter to receive the echo signal reflected back from inside the cookware.

[0109] A temperature sensor is used to detect the temperature of the liquid inside the cookware under the control of the controller. Specifically, the temperature sensor is a non-contact point temperature measurement type (accuracy ±0.5℃) such as infrared, and is arranged adjacent to the ultrasonic sensor.

[0110] The controller is used to implement the steps of the intelligent control method for kitchen appliances based on ultrasonic liquid level detection in any of the above embodiments.

[0111] In this embodiment, ultrasonic waves are emitted towards the cookware area on the stove and the echo signal is received; the peak voltage and rise time in the echo signal are extracted; the rise time is the time required for the ultrasonic wave to reach the target intensity; based on the peak voltage and rise time, the cooking state inside the cookware is assessed to determine whether it is in a dry-burning state; the working state of the range hood or stove is adjusted based on the cooking state, which solves the problems of delayed safety response and lack of autonomous judgment and linkage control capabilities for the cooking process, and realizes real-time and accurate identification of the cookware status and proactive risk prevention and control, thereby comprehensively improving kitchen safety and user experience.

[0112] The present embodiment will now be described and illustrated through preferred embodiments.

[0113] Figure 4 This is a schematic diagram of the structure of the intelligent range hood and stove linkage system of this preferred embodiment, as shown below. Figure 4 As shown, the intelligent range hood and cooktop linkage system includes a range hood 410, a cooktop 420, an ultrasonic sensor 430, and a temperature sensor 440, all connected to the controller.

[0114] The ultrasonic sensor 430, under the control of the controller, emits and receives ultrasonic waves. It is installed on the smoke baffle 411 or the bottom of the range hood 410 and is used to emit ultrasonic waves toward the center of the cookware, at a distance of 300-700mm from the bottom of the cookware, with a resonant frequency of 40kHz±1%.

[0115] Temperature sensor 440, under the control of the controller, detects the temperature of the liquid inside the pot. It is an infrared sensor and is installed adjacent to ultrasonic sensor 430.

[0116] The controller is used to implement the steps of the intelligent control method for kitchen appliances based on ultrasonic liquid level detection, such as... Figure 5 As shown, the intelligent control method for kitchen appliances based on ultrasonic liquid level detection includes the following steps:

[0117] S1, the intelligent range hood and stove linkage system performs a system self-test after power-on, and then starts the intelligent mode.

[0118] S2, in smart mode, enters main detection mode to emit ultrasonic waves to the cookware area on the cooker 420 and receive echo signals; based on the echo signals, it simultaneously executes dry-burning warning algorithm and liquid level detection algorithm to determine the cooking status of the cookware.

[0119] like Figure 6 As shown, the dry-burning warning algorithm includes the following steps:

[0120] S3. After processing the echo signal, extract the characteristic parameters, including peak voltage and rise time. The rise time is the time required for the echo signal to reach the target intensity after the ultrasonic wave is emitted.

[0121] S4, determine whether the peak voltage is greater than the preset voltage threshold and whether the rise time is less than the preset time threshold.

[0122] S5. If the peak voltage is greater than the voltage threshold and the rise time is less than the time threshold, the cookware is determined to be in a dry state, and step S6 is continued; otherwise, the cookware is determined to be in a normal state, and the current fan speed setting of the range hood 410 is maintained.

[0123] S6. If the cookware is in a dry-burning state, the range hood 410 will issue an alarm and be set to the maximum airflow level, and will continuously monitor whether the cookware is in a dry-burning state for a preset monitoring time.

[0124] S7, if the cookware is dry when the monitoring time ends, the heat source of the stove 420 will be turned off; if the cookware is in normal condition when the monitoring time ends, the alarm will be deactivated and the original fan speed will be restored.

[0125] S8, after this round of dry burning warning algorithm ends, upload the result of whether it is in a dry burning state to the cloud and re-enter the main monitoring mode.

[0126] like Figure 7 As shown, the liquid level detection algorithm includes the following steps:

[0127] S9. Determine whether there is a secondary echo in the received echo signal. If there is a secondary echo, proceed to the next step S10; otherwise, generate a low liquid level alarm.

[0128] S10: Obtain the liquid temperature inside the pot and calculate the current liquid sound velocity based on the liquid temperature.

[0129] S11, calculate the time difference between the first and second echoes in the echo signal; based on the time difference and the liquid sound velocity, calculate the liquid level height inside the pot.

[0130] S12: Obtain the time information of the change in liquid level, calculate the rate of change of liquid level based on the time information; determine whether the rate of change of liquid level is greater than the preset change threshold. If so, determine that the pot is in an overflow state and continue to execute S13; otherwise, continue to execute S14.

[0131] S13 generates an overflow alarm and corrects the liquid sound velocity. Based on the corrected liquid sound velocity, it calculates the corrected liquid level height and displays it on the range hood 410 or the stove 420.

[0132] S14, display the liquid level on the range hood 410 or the cooktop 420.

[0133] S15, after this round of liquid level early warning algorithm ends, the predicted results of liquid level height and low liquid level alarm or overflow alarm will be uploaded to the cloud and the main monitoring mode will be re-entered.

[0134] In this preferred embodiment, an ultrasonic sensor installed in the range hood emits ultrasonic pulses to the cookware and analyzes the echo characteristics, solving the problem of insufficient accuracy in real-time detection of the cookware's dry-burning status in existing technologies. Utilizing the acoustic impedance abrupt change effect caused by liquid evaporation (liquid Z≈1.5MRayl → air Z≈0.0004MRayl), a second-level early warning before dry-burning is achieved (response time <500ms). Simultaneously, based on secondary echo and sound velocity compensation, high-precision liquid level monitoring and overflow detection are achieved. This allows the cooktop and range hood to adjust their operating status in real time, providing timely warnings of risks and achieving highly intelligent proactive protection.

[0135] It should be noted that the steps shown in the above process or in the flowchart of the accompanying figures can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowchart, in some cases the steps shown or described may be executed in a different order than that shown here.

[0136] It should be noted that the above modules can be functional modules or program modules, and can be implemented through software or hardware. For modules implemented through hardware, the above modules can reside in the same processor; or the above modules can be located in different processors in any combination.

[0137] Furthermore, in conjunction with the intelligent kitchen appliance control method based on ultrasonic liquid level detection provided in the above embodiments, this embodiment can also provide a storage medium. This storage medium stores a computer program; when executed by a processor, the computer program implements any of the intelligent kitchen appliance control methods based on ultrasonic liquid level detection in the above embodiments.

[0138] It should be understood that the specific embodiments described herein are merely illustrative of the application and not intended to limit it. All other embodiments derived by those skilled in the art based on the embodiments provided in this application without inventive effort are within the scope of protection of this application.

[0139] Obviously, the accompanying drawings are merely some examples or embodiments of this application. Those skilled in the art can apply this application to other similar situations based on these drawings without any creative effort. Furthermore, it is understood that although the work done in this development process may be complex and lengthy, for those skilled in the art, certain design, manufacturing, or production modifications made based on the technical content disclosed in this application are merely conventional technical means and should not be considered as insufficient disclosure of this application.

[0140] The term "embodiment" in this application refers to a specific feature, structure, or characteristic described in connection with an embodiment that may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily imply the same embodiment, nor does it imply that it is mutually exclusive with or independent of other embodiments. It will be clearly or implicitly understood by those skilled in the art that the embodiments described in this application may be combined with other embodiments without conflict.

[0141] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of patent protection. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the appended claims.

Claims

1. A method for intelligent control of kitchen appliances based on ultrasonic liquid level detection, characterized in that, The method includes: It emits ultrasonic waves toward the cookware area on the stove and receives the echo signals; Extract the peak voltage and rise time from the echo signal; the rise time is the time required for the echo signal to reach the target intensity after the ultrasonic wave is emitted. The cooking state of the cookware is evaluated based on the peak voltage and the rise time, the cooking state including at least the dry-burning state; If the cookware is in a dry-burning state, adjust the working status of the range hood or the stove.

2. The intelligent control method for kitchen appliances based on ultrasonic liquid level detection according to claim 1, characterized in that, The cooking state of the cookware is evaluated based on the peak voltage and the rise time, including: Determine whether the peak voltage is greater than a preset voltage threshold and whether the rise time is less than a preset time threshold; If the peak voltage is greater than the voltage threshold and the rise time is less than the time threshold, then the cookware is determined to be in a state of being burned dry. If the peak voltage is less than the voltage threshold, or the rise time is greater than the time threshold, then the cookware is determined to be in a normal state.

3. The intelligent control method for kitchen appliances based on ultrasonic liquid level detection according to claim 2, characterized in that, The voltage threshold is calculated based on a preset mutation coefficient and the obtained calibration intensity; The calibrated intensity is obtained from the echo intensity reflected by the liquid surface in the cookware under normal conditions.

4. The intelligent control method for kitchen appliances based on ultrasonic liquid level detection according to claim 2, characterized in that, If the cookware is in a dry-burning state, adjust the working state of the range hood or the stove, including: If the cookware is in a dry-burning state, the range hood will sound an alarm and be set to the maximum airflow level, and will continuously monitor whether the cookware is in a dry-burning state for a preset monitoring time. If the pot is dry when the monitoring time ends, the heat source of the stove is turned off. If the cookware is in normal condition when the monitoring time ends, the alarm will be deactivated and the original fan speed will be restored.

5. The intelligent control method for kitchen appliances based on ultrasonic liquid level detection according to claim 1, characterized in that, Extracting the peak voltage and rise time from the echo signal includes: Determine whether there is a secondary echo in the received echo signal; If there is no secondary echo in the received echo signal, then extract the peak voltage and rise time in the current echo signal; If a secondary echo is present in the received echo signal, the liquid level in the pot is calculated based on the time difference between the first and second echoes in the echo signal. Based on the liquid level, the range hood or the stove is controlled to output corresponding liquid level indication information.

6. The intelligent control method for kitchen appliances based on ultrasonic liquid level detection according to claim 5, characterized in that, The liquid level in the pot is calculated based on the time difference between the first and second echoes in the echo signal, including: Calculate the time difference between the first echo and the second echo in the echo signal; The temperature of the liquid inside the cookware is obtained, and the current speed of sound in the liquid is calculated based on the liquid temperature. Based on the time difference and the speed of sound in the liquid, the liquid level in the pot is calculated.

7. The intelligent control method for kitchen appliances based on ultrasonic liquid level detection according to claim 6, characterized in that, After calculating the liquid level height inside the pot based on the time difference and the liquid sound velocity, the method further includes: Obtain the time information of the change in liquid level, and calculate the rate of change of liquid level based on the time information; If the rate of change of the liquid level is greater than a preset threshold, the pot is determined to be in an overflow state. The liquid sound velocity is corrected based on the overflow state, and the corrected liquid level height is calculated based on the corrected liquid sound velocity; or the range hood or stove is controlled to output corresponding boiling warning information based on the overflow state.

8. An intelligent range hood and stove linkage system, characterized in that, The system includes a range hood, a cooktop, an ultrasonic sensor, and a temperature sensor, all connected to a controller; wherein the ultrasonic sensor and the temperature sensor are mounted on the range hood. The ultrasonic sensor is used to emit and receive ultrasonic waves under the control of the controller. The temperature sensor is used to detect the temperature of the liquid inside the cookware under the control of the controller. The controller is used to implement the steps of the method according to any one of claims 1 to 7.

9. The intelligent range hood and stove linkage system according to claim 8, characterized in that, The ultrasonic sensor is installed at the bottom of the smoke baffle or air inlet panel of the cooking fume hood, facing the center of the cookware, with a resonant frequency of 40kHz.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 7.

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