Cooking recognition method based on intelligent range hood and intelligent range hood

Abstract

The application relates to a cooking recognition method based on an intelligent range hood and the intelligent range hood, and is applied to the field of intelligent electrical appliances, wherein the cooking recognition method based on the intelligent range hood comprises the following steps: acquiring an acoustic wave reflection signal received by an ultrasonic transceiving module; the acoustic wave reflection signal is a narrowband acoustic signal obtained by reflection of an ultrasonic wave signal emitted by the ultrasonic transceiving module to a pot placed on a cooking bench; acquiring a microphone receiving signal received by a microphone sensing module; the microphone receiving signal is a broadband acoustic signal generated by a cooking action of a current user; and the cooking action of the current user is recognized according to an acoustic wave feature in the acquired acoustic wave reflection signal or microphone receiving signal. Through the application, the problem that the efficiency and safety of user cooking action recognition are low during user cooking is solved.

Description

Technical Field

[0001] This application relates to the field of smart appliances, and in particular to a cooking recognition method based on a smart range hood and a smart range hood. Background Technology

[0002] As people's living standards improve and technologies such as the internet, big data, artificial intelligence, and voice interaction become more widespread, traditional lifestyles are gradually changing, and the use of home appliances is increasingly moving towards intelligentization. While bringing more convenience to users, the functions of various home appliances are also becoming more diversified.

[0003] Smart range hoods are essential appliances for daily cooking, and as users' demands for intelligent range hoods increase, there's a need for automatic control based on user actions and cooking scenarios to enhance the user experience. Currently, cameras are generally used to monitor and identify the user's cooking process; however, this method carries risks of privacy breaches and suffers from response delays.

[0004] There is currently no effective solution to the problem of low efficiency and security in recognizing user cooking actions during the cooking process using related technologies. Summary of the Invention

[0005] This embodiment provides a cooking recognition method based on a smart range hood and a smart range hood to solve the problems of low efficiency and safety in recognizing user cooking actions during the cooking process in related technologies.

[0006] In a first aspect, this embodiment provides a cooking recognition method based on a smart range hood, wherein a microphone sensing module and an ultrasonic transceiver module are provided on the smoke baffle of the smart range hood; the method includes:

[0007] The ultrasonic transceiver module receives the reflected sound wave signal; the reflected sound wave signal is a narrowband sound signal obtained by the ultrasonic transceiver module emitting an ultrasonic signal to the pot placed on the stove and then reflecting it off the pot.

[0008] The microphone received signal received by the microphone sensing module is acquired; the microphone received signal is a broadband sound signal generated by the current user's cooking action.

[0009] The current user's cooking actions are identified based on the acoustic wave characteristics in the acquired acoustic wave reflection signal or the microphone received signal.

[0010] In some embodiments, determining the current user's cooking action based on the sound wave reflection signal includes:

[0011] The reflected sound wave signal is subjected to spectral analysis to obtain a discrete spectrum, and the spectral peak of the sound wave in the discrete spectrum is extracted.

[0012] Based on the peak frequency and the initial resonant frequency, the spectral offset is determined; the initial resonant frequency is the signal frequency obtained by the ultrasonic transceiver module transmitting an ultrasonic signal to the cookware on the stove when the cookware is not covered by a lid, and the signal is reflected by the cookware.

[0013] Based on the spectral offset, determine whether there is a lid on the pot currently placed on the stove.

[0014] In some embodiments, determining the current user's cooking action based on the sound wave reflection signal further includes:

[0015] The Doppler frequency shift of the sound wave is obtained by performing spectral analysis on the reflected sound wave signal during the user's movement of the cookware; the Doppler frequency shift is determined based on the angle between the moving speed and the moving direction of the cookware when the user moves it.

[0016] Based on the time-domain repetitive characteristics of the sound wave reflection signal, the frequency of the user's movement cycle when moving the cookware is obtained.

[0017] Based on the Doppler frequency shift and the action cycle frequency, it is determined whether the current user's cooking action is a tossing action.

[0018] In some embodiments, multiple ultrasonic transceiver modules are configured, and the multiple ultrasonic transceiver modules are arranged in a ring at the same horizontal height of the smoke baffle; the method further includes:

[0019] Based on the ultrasonic signals emitted by the ultrasonic transceiver module and the received sound wave reflection signals, the moving speed of the cookware when the user moves it is determined.

[0020] Based on the time difference between the arrival times of the ultrasonic signals emitted by the multiple ultrasonic transceiver modules at the stove, and the straight-line distance between the multiple ultrasonic transceiver modules and the stove, the direction angle of the pot's movement when the user moves the pot is determined.

[0021] The Doppler frequency shift is determined based on the moving speed, the direction angle of motion, the preset sound speed, and the initial resonant frequency; the preset sound speed is the speed at which sound waves propagate in the atmosphere under a preset ideal state.

[0022] In some embodiments, a temperature sensor is also provided on the smoke baffle of the smart range hood; the method further includes:

[0023] The ambient temperature is acquired by a temperature sensor, and the preset sound velocity is corrected based on the ambient temperature.

[0024] In some embodiments, identifying the current user's cooking action based on the acoustic wave characteristics in the acquired acoustic wave reflection signal or the microphone received signal includes:

[0025] Obtain the signal voltage of the sound wave in the signal received by the microphone;

[0026] Based on the signal voltage and the corresponding sound pressure change time, the sound pressure change rate of the signal received by the microphone is determined; the sound wave characteristics include the sound pressure change rate in the sound wave.

[0027] The cooking ingredients that the current user adds to the pot are determined based on the sound pressure change rate and the sound pressure change time.

[0028] In some embodiments, after identifying the current user's cooking action, the method further includes:

[0029] Based on the identified cooking actions, the cooking mode and light brightness of the smart range hood are adjusted.

[0030] Secondly, this embodiment provides a smart range hood, which uses the cooking recognition method based on the smart range hood as described in any one of the first aspects to recognize the current user's cooking actions.

[0031] Thirdly, this embodiment provides an electronic device including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the cooking recognition method based on a smart range hood described in the first aspect above.

[0032] Fourthly, this embodiment provides a storage medium storing a computer program that, when executed by a processor, implements the cooking recognition method based on an intelligent range hood as described in the first aspect.

[0033] Compared with related technologies, the cooking recognition method and smart range hood provided in this embodiment involve setting an ultrasonic transceiver module and a microphone sensing module on the smoke baffle of the smart range hood. The ultrasonic transceiver module emits ultrasonic signals and actively receives narrowband filtered sound wave reflection signals, while the microphone sensing module passively receives broadband filtered microphone reception signals. The acoustic wave characteristics in the signals are analyzed comprehensively to determine the current user's cooking actions. Determining the current user's cooking actions through sound wave signals does not infringe on the user's cooking privacy and reduces response latency, thereby improving the efficiency and security of user cooking action recognition.

[0034] 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

[0035] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0036] Figure 1 This is a hardware structure block diagram of the terminal of the cooking recognition method based on a smart range hood provided in the embodiments of this application;

[0037] Figure 2 This is a schematic diagram of the structure of the cooking apparatus provided in the embodiments of this application;

[0038] Figure 3 This is a schematic diagram of the sound wave signal acquisition device for cooking provided in the embodiments of this application;

[0039] Figure 4 This is a flowchart of a cooking recognition method based on a smart range hood provided in an embodiment of this application;

[0040] Figure 5 This is a flowchart of the cooking scene recognition method provided in this specific embodiment;

[0041] Figure 6 This is a schematic diagram showing the location of the sensor module in the smoke baffle provided in an embodiment of this application;

[0042] Figure 7 This is a flowchart of a cooking detection method based on a smart range hood provided in this specific embodiment.

[0043] Reference numerals: 10, Intelligent range hood; 11, Smoke baffle; 12, Ultrasonic transceiver module; 13, Microphone sensor module; 14, Temperature sensor; 20, Cooktop; 102, Processor; 104, Memory; 106, Transmission device; 108, Input / output device. Detailed Implementation

[0044] To better understand the purpose, technical solution, and advantages of this application, the application is described and illustrated below in conjunction with the accompanying drawings and embodiments.

[0045] Unless otherwise defined, the technical or scientific terms used in this application shall have the general meaning understood by a person skilled 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, or 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.

[0046] 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 cooking recognition method based on a smart range hood provided in this application embodiment. 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 1 The 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.

[0047] The memory 104 can be used to store computer programs, such as application software programs and modules, like the computer program corresponding to the cooking recognition method based on a smart range hood 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.

[0048] 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.

[0049] To address the issues of low efficiency and safety in recognizing user cooking actions during the cooking process in existing technologies, this embodiment provides a cooking recognition method based on a smart range hood. This method involves emitting directional ultrasonic waves towards the stove and receiving the reflected sound waves. A microphone receiving module receives the received microphone signal, and the frequency shift and resonance characteristics of the reflected sound waves and the received microphone signal are analyzed to obtain corresponding quantitative acoustic parameters. Based on these quantitative acoustic parameters, cooking actions such as tossing the pan, covering the pot, and adding ingredients to the pan are determined.

[0050] Figure 2 This is a schematic diagram of the cooking apparatus provided in an embodiment of this application. (Reference) Figure 2 The user stands in front of the cooking device during the cooking process; the cooking device includes a smart range hood 10 and a stove 20 for placing cookware. The smart range hood 10 is equipped with a smoke baffle 11, and the smoke baffle 11 in the smart range hood 10 is equipped with a microphone sensing module 13 and an ultrasonic transceiver module 12. Figure 3 This is a schematic diagram of the sound wave signal acquisition device for cooking provided in an embodiment of this application. (Reference) Figure 3The system employs a directional active detection module with an ultrasonic transceiver module to measure distance to the stove area, the angle of motion of cooking actions, and speed detection, achieving precise positioning. Simultaneously, an omnidirectional passive listening module, including a wideband microphone array, captures the characteristics of sonic booms, ambient noise, and material resonance in the stove area. Subsequently, the reflected sound waves received by the ultrasonic transceiver module and the microphone sensing module with the wideband microphone array are processed by a signal processing module to identify the user's cooking actions.

[0051] Figure 4 This is a flowchart of a cooking recognition method based on a smart range hood provided in an embodiment of this application. This cooking method is applied in applications such as... Figure 2 In the cooking apparatus shown, such as Figure 4 As shown, the process includes the following steps S410 to S430.

[0052] Step S410: Obtain the acoustic wave reflection signal received by the ultrasonic transceiver module; the acoustic wave reflection signal is a narrowband acoustic signal obtained by the ultrasonic transceiver module emitting an ultrasonic signal to the pot placed on the stove and then reflecting it through the pot.

[0053] In this process, the processor controls the ultrasonic transceiver module to transmit high-frequency sound waves, i.e. ultrasonic signals, to the stove. During the propagation of the ultrasonic signals, the reflections of the cookware, including the user's different cooking actions on the stove, can obtain sound wave reflection signals that represent different cooking actions. The ultrasonic transceiver module then receives these sound wave reflection signals and identifies the current user's cooking actions based on the sound wave reflection signals.

[0054] Step S420: Obtain the microphone received signal from the microphone sensor module; the microphone received signal is a broadband sound signal generated by the current user's cooking action.

[0055] Since the ultrasonic transceiver module receives narrowband filtered acoustic signals from reflected sound waves, it cannot include broadband filtered acoustic signals. Therefore, a microphone sensor module can be set up to passively receive microphone signals generated by the user's various cooking actions. Then, by combining the reflected sound waves and the received microphone signals, and leveraging the characteristics of narrowband active detection and broadband passive listening, the user's cooking actions can be fully identified, further improving the accuracy of identifying user cooking actions.

[0056] Step S430: Identify the current user's cooking action based on the sound wave characteristics in the acquired sound wave reflection signal or microphone received signal.

[0057] Specifically, after the ultrasonic transceiver module actively detects and obtains the reflected sound wave signal, and the microphone sensor module including a wideband microphone array passively listens to obtain the received microphone signal, the sound wave features in the reflected sound wave signal / received microphone signal are extracted, and then the current user's cooking action is identified based on the sound wave features.

[0058] After recognizing the current user's cooking actions, the smart range hood adjusts its cooking mode and light brightness based on the recognized actions.

[0059] By analyzing the changes in pitch, volume, and timbre of the reflected sound waves, the system can determine the user's current cooking action. For example, when the user's cooking action is "covering the pot," the cooking sound can be considered "muffled," and the frequency of the reflected sound wave signal decreases, corresponding to a significantly lower pitch. When the user's cooking action is "tossing the pot," the pot moves rapidly, and the sound waves in the reflected sound wave signal become sharper, exhibiting rhythmic pitch changes. When the user's cooking action is "adding ingredients to the pot," for example, when cooler ingredients come into contact with hot oil in the pot, they produce a small "sizzling" sound, and the reflected sound wave signal instantly becomes very loud, with a sharp increase in sound pressure level.

[0060] Therefore, by calculating "how much the pitch has changed", "whether there are regular pitch fluctuations", and "whether the volume suddenly increases", it can accurately identify whether the user is covering the pot, tossing the food, or adding ingredients, and thus automatically adjust the fan speed and lighting to keep the kitchen comfortable at all times.

[0061] Through the above steps, an ultrasonic transceiver module and a microphone sensing module are installed on the smoke baffle of the smart range hood. The ultrasonic transceiver module emits ultrasonic signals and actively receives narrowband filtered sound wave reflection signals, while the microphone sensing module passively receives broadband filtered microphone reception signals. The acoustic wave characteristics in the signals are analyzed comprehensively to determine the current user's cooking actions. Determining the current user's cooking actions through acoustic signals does not infringe on the user's cooking privacy and reduces response latency, thereby improving the efficiency and security of user cooking action recognition.

[0062] Figure 5 This is a flowchart of the cooking scene recognition method provided in this specific embodiment. (Reference) Figure 5 After acquiring the raw sound wave signal (i.e., the sound wave reflection signal and the microphone reception signal) through the ultrasonic transceiver module and the microphone sensor module, the raw sound wave signal is processed. Feature branches in the processed raw sound wave signal are extracted and used for pot lid opening and closing detection, pot tossing action detection, and food entering the pot detection, respectively.

[0063] In some embodiments, when detecting the opening and closing of the pot lid, it is necessary to calculate the spectral offset in the current sound wave reflection signal. and will The current state of the pot lid is determined by comparing it with a threshold.

[0064] Specifically, step S430 determines the current user's cooking action based on the sound wave reflection signal, including steps S431 to S433.

[0065] Step S431: Perform spectral analysis on the sound wave reflection signal to obtain a discrete spectrum, and extract the spectral peaks of the sound wave in the discrete spectrum.

[0066] Step S432: Determine the spectral offset based on the peak spectral value and the initial resonant frequency; the initial resonant frequency is the signal frequency obtained by the ultrasonic transceiver module transmitting an ultrasonic signal to the cookware on the stove when the cookware is not covered by a lid, and the signal is reflected by the cookware.

[0067] Step S433: Determine whether there is a lid on the pot currently placed on the stove based on the spectral offset.

[0068] When the lid is closed, the cookware forms a semi-enclosed cavity. At this time, the acoustic impedance in the reflected sound wave signal acquired by the ultrasonic transceiver module increases dramatically, causing the resonant frequency to shift from high to low frequencies, and vice versa. Therefore, spectral analysis, such as Fast Fourier Transform, can be performed on the reflected sound wave signal to obtain the spectral peak value in the discrete spectrum corresponding to the reflected sound wave signal, which is the real-time resonant frequency. Then, based on the difference between the real-time resonant frequency and the initial resonant frequency, the spectral offset, i.e., the resonant frequency offset, is determined. The spectral offset is used to determine whether a lid is currently placed on the cookware.

[0069] Furthermore, the detection of whether a lid is placed on the current cookware can be expressed by the following formula:

[0070] ;

[0071] in, This refers to the peak value of the spectrum extracted from the reflected sound wave signal, which is the real-time resonant frequency. Indicates the no-load resonant frequency. This represents the spectral offset, i.e., the resonant frequency offset. The preset sound velocity is indicated, which is usually set to 340m / s; L represents the distance from the pot lid to the current ultrasonic transceiver module, which can be measured based on the ultrasonic transceiver module. This represents the air acoustic impedance, which is 410 Rayl. This indicates the acoustic impedance of the pot lid. Pot lids are typically made of materials such as iron and glass. The acoustic impedance of iron is approximately 7.8 × 10⁻⁶.6 Rayl, the acoustic impedance of the glass is approximately 8.1 × 10⁻⁶. 6 Rayl.

[0072] Therefore, by combining the sound wave reflection signal obtained by the ultrasonic transceiver module, the current spectral offset can be calculated. Based on the different acoustic impedances of the lid being closed and open corresponding to the spectral offset, it can be determined whether the current cooking action is closing or opening the lid.

[0073] In some embodiments, when detecting the tossing motion, it is necessary to detect the Doppler frequency shift corresponding to the sound wave reflection signal received by the ultrasonic transceiver module. and action cycle frequency Then, a dual-feature threshold judgment is performed to confirm whether the user's current cooking action is a tossing action.

[0074] Specifically, after the ultrasonic transceiver module acquires the sound wave reflection signal, it can also identify the user's current wok-tossing action based on the Doppler frequency shift in the sound wave reflection signal. Specifically, determining the user's current cooking action based on the sound wave reflection signal also includes: performing spectral analysis on the sound wave reflection signal to obtain the Doppler frequency shift of the sound waves during the user's movement of the wok; the Doppler frequency shift is determined based on the angle between the wok's moving speed and direction when the user moves the wok; obtaining the periodic frequency of the user's wok-tossing action based on the time-domain repetition characteristics of the sound wave reflection signal; and determining whether the user's current cooking action is a wok-tossing action based on the Doppler frequency shift and the periodic frequency.

[0075] This process requires Doppler analysis of the received sound wave reflection signal to determine the Doppler frequency shift corresponding to the user's wok-tossing motion. The Doppler frequency shift reflects the instantaneous linear velocity of the cookware, corresponding to the intensity / amplitude of the user's cooking action. The Doppler frequency shift in the sound wave reflection signal... It can be expressed by the following formula:

[0076] ;

[0077] in, This represents the no-load resonant frequency, typically set to 40kHz; c represents the preset sound velocity, typically set to 340m / s; v represents the speed at which the cookware moves during cooking. This indicates the angle of movement of the cookware during the user's cooking process.

[0078] Doppler frequency shift can be obtained by direct detection of sound wave reflection signals. Simultaneously, the motion cycle frequency in the sound wave reflection signal is extracted using Fast Fourier Transform. The action cycle frequency is used to reflect the rhythmicity, or time domain repeatability, of the user's wok-tossing action. This is based on the Doppler frequency shift. and action cycle frequency If it is determined that the current cookware has a periodic frequency shift, the current user's cooking action is determined to be a tossing action.

[0079] In some embodiments, multiple ultrasonic transceiver modules are configured, and the multiple ultrasonic transceiver modules are arranged in a ring at the same horizontal height of the smoke baffle.

[0080] Preferably, refer to Figure 6 , Figure 6 This is a schematic diagram showing the position of the sensor module in the smoke baffle provided in this application embodiment. Three sets of ultrasonic transceiver modules 12 are arranged in a 120° ring, and their tilt angle towards the cooking area is set to strong orientation ±15° to eliminate detection blind spots; and they measure the movement angle of the cookware during the user's cooking process.

[0081] Further, refer to Figure 6 It also includes a microphone sensing module 13 for receiving microphone signals with a wide frequency range of 20Hz-20kHz, capturing mid-frequency sonic booms (e.g., 2kHz-8kHz) when food is added to the pan, and monitoring the ambient noise floor. A temperature sensor 14 is used to compensate for changes in sound velocity.

[0082] The speed v of the cookware during the user's cooking process and the angle of movement of the cookware during the user's cooking process. The method is as follows: Based on the ultrasonic signals emitted by the ultrasonic transceiver module and the received sound wave reflection signals, the moving speed of the cookware when the user moves it is determined; based on the time difference between the arrival times of the ultrasonic signals emitted by multiple ultrasonic transceiver modules at the stove, and the straight-line distance between the multiple ultrasonic transceiver modules and the stove, the motion direction angle of the cookware when the user moves it is determined; based on the moving speed, motion direction angle, preset sound velocity, and initial resonant frequency, the Doppler frequency shift is determined; the preset sound velocity is the speed at which sound waves propagate in the atmosphere under preset ideal conditions.

[0083] refer to Figure 6 The ultrasonic transceiver module 12 is positioned to include a first, second, and third ultrasonic transceiver module. The direction of movement of the cookware during cooking is calculated by using the time difference in arrival of sound waves from different ultrasonic transceiver modules. The time difference in arrival of sound waves between the first and second ultrasonic transceiver modules is also considered. It can be expressed by the following formula:

[0084] ;

[0085] in, This indicates the arrival time of the sound wave from the first ultrasonic transceiver module. d represents the arrival time of the sound wave from the second ultrasonic transceiver module, d represents the distance between the ultrasonic transceiver module and the center of the stove, and c represents the sound velocity obtained after correcting the preset sound velocity based on the ambient temperature, which is set to 346m / s. This indicates the angle of movement of the cookware during the cooking process, that is, the angle between the direction of movement of the cookware and the horizontal axis.

[0086] After the ultrasonic transceiver module transmits a 40kHz ultrasonic pulse, the arrival times of the reflected waves from the three ultrasonic transceiver modules are recorded respectively. , and ; then based on the above calculations The formula is used to deduce the angle of movement of the cookware during the user's cooking process. It can be represented as:

[0087] ;

[0088] in, This represents the time difference of sound wave arrival between the first and second ultrasonic transceiver modules. This represents the time difference of sound wave arrival between the first and third ultrasonic transceiver modules. This indicates the time difference of sound wave arrival between the second and third ultrasonic transceiver modules.

[0089] In some of these embodiments, reference is made to Figure 2 and Figure 6 The smart range hood 10 also has a temperature sensor 14 installed on its smoke baffle 11. The cooking recognition method based on the smart range hood further includes: acquiring the ambient temperature collected by the temperature sensor and correcting the preset sound velocity according to the ambient temperature.

[0090] Specifically, the corrected speed of sound It can be represented as:

[0091] ;

[0092] Here, T represents the ambient temperature collected by the temperature sensor. By correcting the sound velocity c value in real time using the temperature sensor, detection errors caused by stove heating are eliminated, thereby improving the detection accuracy of the user's current cooking actions.

[0093] In some embodiments, the sound pressure change rate K and the sound pressure change time are calculated based on the microphone received signal passively received by the microphone sensing module. Therefore, the ingredients are confirmed to be cooked based on these two characteristics.

[0094] Specifically, the current user's cooking action is determined based on the sound wave characteristics in the microphone received signal, including: acquiring the signal voltage of the sound wave in the microphone received signal; determining the sound pressure change rate of the microphone received signal based on the signal voltage and the corresponding sound pressure change time; the sound wave characteristics include the sound pressure change rate in the sound wave; and determining the cooking ingredients that the current user adds to the pot based on the sound pressure change rate and the sound pressure change time.

[0095] Specifically, after the microphone sensing module passively receives the microphone signal, it determines the voltage change rate in the microphone signal; based on the sound pressure change rate, it determines whether there is food in the pot at that time.

[0096] The present embodiment will be described and explained below through specific examples.

[0097] Figure 7 This is a flowchart of a cooking detection method based on a smart range hood provided in this specific embodiment. It can not only detect and identify the user's cooking actions, but also automatically adjust the air volume and other parameters according to the scenario to provide a better intelligent cooking experience.

[0098] refer to Figure 7 After the smart range hood performs a self-test upon startup, it emits a 40kHz directional ultrasonic wave towards the cooktop and receives the corresponding raw sound wave signal, namely the sound wave reflection signal and the microphone reception signal in the aforementioned embodiment. The raw sound wave signal is then preprocessed, for example, by performing bandpass filtering or wavelet noise reduction before feature extraction. Subsequently, based on the extracted sound wave features, including the spectral offset in the aforementioned embodiment... Doppler frequency shift and action cycle frequency And the rate of change of sound pressure K and the time of change of sound pressure. It makes decisions based on the current cooking status, and then controls the fan speed, cooking mode, and lights in the smart range hood.

[0099] Specifically, in determining the spectral offset If the frequency exceeds the preset threshold of 1.8kHz, it indicates that the pot is covered and the user needs to steam or cook the food inside. Therefore, the fan speed of the smart range hood should be reduced to a low setting / steaming / cooking mode. This is based on the determination of the frequency offset. If the frequency does not exceed the preset threshold of -1.8kHz, it means that the pot is not covered with a lid. In this case, the smart range hood needs to be switched to the stir-fry mode for 10 seconds and then returned to the original mode.

[0100] In a preferred embodiment, the peak frequency of the sound wave reflection signal extracted during the lid closing process is the real-time resonant frequency. The real-time resonant frequency is the peak frequency extracted from the reflected sound wave signal in the closed state at 40kHz. It is 37.82kHz, therefore The value is 2.18kHz, which is higher than 1.8kHz, indicating that the pot is covered with a lid at this time, and the lid is closed.

[0101] The peak frequency of the sound wave reflected during the process of opening the pot lid is the real-time resonant frequency, which is extracted from the spectral peak of the sound wave reflected from the open lid state. The frequency is 41.95kHz. The peak value of the spectrum extracted from the sound wave reflection signal in the closed state is the real-time resonant frequency. It is 37.82kHz, therefore The value is -1.95kHz, which is less than 1.8kHz, indicating that the pot is covered with a lid at this time, and the lid is open at the detection position.

[0102] In determining Doppler frequency shift The absolute value exceeds 180Hz, and the operating cycle frequency When the frequency is between 0.5Hz and 2Hz, the current user's cooking action is determined to be a tossing motion, and the smart range hood is controlled to increase the fan speed to the stir-fry mode.

[0103] When determining whether a cooking action is a tossing motion, if only Doppler frequency shift is used... The Doppler frequency shift generated when a user waves their hand quickly A value of 350Hz can also be misinterpreted as a wok toss; if only the operating cycle frequency is used... So, the frequency of the action cycle generated when the user stirs slowly. Even at 0.8Hz, it can be misinterpreted as a pot flipping. Therefore, it is necessary to consider the Doppler frequency shift. and action cycle frequency To determine if a tossing motion is valid.

[0104] As a preferred embodiment, when the action cycle frequency is detected... The frequency is 1.2 Hz, and the Doppler frequency shift is... The value during the upward throw phase is 310Hz, with a Doppler frequency shift. The frequency shift during the descent phase is -285Hz, at which point the Doppler frequency shift occurs. The absolute values ​​all exceed 180Hz, and the operating cycle frequency If the frequency is between 0.5Hz and 2Hz, the current user's cooking action is determined to be a tossing motion.

[0105] Doppler frequency shift was detected. The value is 380Hz, which exceeds 180Hz, and the operating cycle frequency... If the frequency is 0.3Hz, and it is not between 0.5Hz and 2Hz, then the current user's cooking action is determined to be not a tossing action.

[0106] Doppler frequency shift was detected. The absolute value is 120Hz, not exceeding 180Hz, and the operating cycle frequency... When the frequency is between 0.5Hz and 2Hz, it is determined that the current user's cooking action is not a tossing motion.

[0107] If the sound pressure change rate K exceeds 45dB / s and the sound pressure change time Δt is less than 0.5s, it means that there is food in the pot at this time. The smart range hood needs to be controlled to instantly increase the pressure to the stir-fry mode, and then return to the original mode after 10 seconds.

[0108] The rate of change of sound pressure, K, can be expressed by the following formula:

[0109] ;

[0110] in, It represents the change in sound pressure level, which is generally between 40-100 dB and is determined by the ratio of the microphone voltage V to the reference voltage V0 in the signal received by the microphone. This indicates the rise time of the signal, typically between 0.1 and 0.5 seconds. This indicates the background sound pressure level of the signal received by the microphone. This indicates the peak sound pressure level of the signal received by the microphone.

[0111] As a preferred embodiment, when vegetables are added to the pot, the background sound pressure level is... The peak sound pressure level is 52 dB. With a sound pressure level of 89 dB and a sound pressure rise time of 0.15 s, the calculated sound pressure rate of change is 246.7 dB / s, exceeding 4545 dB / s, and the sound pressure change time... If the time is less than 0.5 seconds, it is determined that ingredients including vegetables have been added to the pot.

[0112] The background sound pressure level when adding water to the pot. 48dB, peak sound pressure level With a sound pressure level of 65 dB and a sound pressure rise time of 0.08 s, the calculated sound pressure change rate is 212.5 dB / s, exceeding 4545 dB / s, and the sound pressure change time... If the time is less than 0.5 seconds, it is determined that the food, including a small amount of liquid, has been put into the pot.

[0113] After switching the cooking mode of the current smart range hood to the stir-fry mode, the lighting will be synchronized accordingly, that is, the brightness of the lights in the smart range hood will increase by 30% in the stir-fry mode.

[0114] In this specific embodiment, the original sound wave signal is detected by the ultrasonic transceiver module and the microphone sensing module. Based on the sound wave characteristics in the original sound wave signal, combined with the acoustic impedance difference of the metal pot lid, the periodic movement characteristics of the pot, the reasonable range of ergonomics, the characteristics of liquid-solid contact sonic boom, and the instantaneous energy release characteristics, the opening and closing state of the pot lid, the tossing action, and the action of putting ingredients into the pot during the current cooking process are determined.

[0115] By analyzing the frequency shift of reflected sound waves (the Doppler effect) and resonance characteristics (acoustic impedance abrupt changes), cooking actions such as tossing the pan, covering the pot, and adding ingredients are transformed into quantified acoustic parameters, establishing an "action-soundprint" database to control the fan. Compared to traditional methods of cooking recognition using cameras, the response latency is reduced to 0.3-0.5 seconds, significantly lower; furthermore, pure acoustic judgment poses no privacy risks, and the ultrasonic system consumes less power. Therefore, it solves the privacy leakage and response delay problems of visual solutions, achieving accurate identification of stir-frying / steaming / boiling state switching within ±0.5 seconds.

[0116] This embodiment also provides an intelligent range hood device for implementing the above embodiments and preferred embodiments; details already described will not be repeated. The terms "module," "unit," and "subunit," etc., used below refer to combinations of software and / or hardware that achieve a predetermined function. Although the device described in the following embodiments is preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0117] This intelligent range hood device includes a main controller, and ultrasonic transceiver module, microphone sensor module, temperature detection module, lighting control module, and storage module, all connected to the main controller. The main controller executes the aforementioned cooking recognition method based on the intelligent range hood to identify the user's cooking actions and the cooking scenario. In addition, the intelligent range hood also includes a switch module, fan drive module, communication module, and optional smoke guide plate adjustment module, enabling various intelligent functions.

[0118] 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.

[0119] This embodiment also provides an electronic device including a memory and a processor, the memory storing a computer program and the processor being configured to run the computer program to perform the steps in any of the above method embodiments.

[0120] Optionally, the electronic device may further include a transmission device and an input / output device, wherein the transmission device is connected to the processor and the input / output device is connected to the processor.

[0121] Optionally, in this embodiment, the processor can be configured to perform the following steps via a computer program:

[0122] S1, acquire the acoustic wave reflection signal received by the ultrasonic transceiver module; the acoustic wave reflection signal is a narrowband acoustic signal obtained by the ultrasonic transceiver module emitting an ultrasonic signal to the pot placed on the stove and then reflecting it through the pot.

[0123] S2, acquire the microphone received signal received by the microphone sensor module; the microphone received signal is a broadband sound signal generated by the current user's cooking action.

[0124] S3 identifies the current user's cooking actions based on the sound wave characteristics in the acquired sound wave reflection signal or the microphone received signal.

[0125] It should be noted that the specific examples in this embodiment can refer to the examples described in the above embodiments and optional implementations, and will not be repeated in this embodiment.

[0126] Furthermore, in conjunction with the cooking recognition method based on a smart range hood provided in the above embodiments, this embodiment can also provide a storage medium for implementation. This storage medium stores a computer program; when executed by a processor, the computer program implements any of the cooking recognition methods based on a smart range hood described in the above embodiments.

[0127] 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.

[0128] 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.

[0129] 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.

[0130] 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 cooking recognition method based on a smart range hood, characterized in that, The intelligent range hood has a microphone sensing module and an ultrasonic transceiver module installed on the smoke baffle plate; the method includes: The ultrasonic transceiver module receives the reflected sound wave signal; the reflected sound wave signal is a narrowband sound signal obtained by the ultrasonic transceiver module emitting an ultrasonic signal to the pot placed on the stove and then reflecting it off the pot. The microphone received signal received by the microphone sensing module is acquired; the microphone received signal is a broadband sound signal generated by the current user's cooking action. The current user's cooking actions are identified based on the acoustic wave characteristics in the acquired acoustic wave reflection signal or the microphone received signal.

2. The cooking recognition method based on a smart range hood according to claim 1, characterized in that, Determining the current user's cooking action based on the sound wave reflection signal includes: The reflected sound wave signal is subjected to spectral analysis to obtain a discrete spectrum, and the spectral peak of the sound wave in the discrete spectrum is extracted. Based on the peak frequency and the initial resonant frequency, the spectral offset is determined; the initial resonant frequency is the signal frequency obtained by the ultrasonic transceiver module transmitting an ultrasonic signal to the cookware on the stove when the cookware is not covered by a lid, and the signal is reflected by the cookware. Based on the spectral offset, determine whether there is a lid on the pot currently placed on the stove.

3. The cooking recognition method based on a smart range hood according to claim 2, characterized in that, The step of determining the current user's cooking action based on the sound wave reflection signal further includes: The Doppler frequency shift of the sound wave is obtained by performing spectral analysis on the reflected sound wave signal during the user's movement of the cookware; the Doppler frequency shift is determined based on the angle between the moving speed and the moving direction of the cookware when the user moves it. Based on the time-domain repetitive characteristics of the sound wave reflection signal, the frequency of the user's movement cycle when moving the cookware is obtained. Based on the Doppler frequency shift and the action cycle frequency, it is determined whether the current user's cooking action is a tossing action.

4. The cooking recognition method based on a smart range hood according to claim 3, characterized in that, The ultrasonic transceiver module is configured as a plurality of modules, and the plurality of ultrasonic transceiver modules are arranged in a ring at the same horizontal height of the smoke baffle; the method further includes: Based on the ultrasonic signals emitted by the ultrasonic transceiver module and the received sound wave reflection signals, the moving speed of the cookware when the user moves it is determined. Based on the time difference between the arrival times of the ultrasonic signals emitted by the multiple ultrasonic transceiver modules at the stove, and the straight-line distance between the multiple ultrasonic transceiver modules and the stove, the direction angle of the pot's movement when the user moves the pot is determined. The Doppler frequency shift is determined based on the moving speed, the direction angle of motion, the preset sound speed, and the initial resonant frequency; the preset sound speed is the speed at which sound waves propagate in the atmosphere under a preset ideal state.

5. The cooking recognition method based on a smart range hood according to claim 4, characterized in that, The intelligent range hood also has a temperature sensor installed on its smoke baffle; the method further includes: The ambient temperature is acquired by a temperature sensor, and the preset sound velocity is corrected based on the ambient temperature.

6. The cooking recognition method based on a smart range hood according to claim 1, characterized in that, The step of identifying the current user's cooking action based on the sound wave characteristics in the acquired sound wave reflection signal or the microphone received signal includes: Obtain the signal voltage of the sound wave in the signal received by the microphone; Based on the signal voltage and the corresponding sound pressure change time, the sound pressure change rate of the signal received by the microphone is determined; the sound wave characteristics include the sound pressure change rate in the sound wave. The cooking ingredients that the current user adds to the pot are determined based on the sound pressure change rate and the sound pressure change time.

7. The cooking recognition method based on a smart range hood according to any one of claims 1 to 6, characterized in that, After identifying the current user's cooking actions, the process also includes: Based on the identified cooking actions, the cooking mode and light brightness of the smart range hood are adjusted.

8. A smart range hood, characterized in that, The intelligent range hood uses the cooking recognition method based on the intelligent range hood as described in any one of claims 1 to 7 to recognize the current user's cooking actions.

9. An electronic device comprising a memory and a processor, characterized in that, The memory stores a computer program, and the processor is configured to run the computer program to perform the cooking recognition method based on a smart range hood as described in any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of the cooking recognition method based on the intelligent range hood as described in any one of claims 1 to 7.

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