Refrigerator door-closing-not alarm control method and system

Abstract

The invention discloses a refrigerator door-closing-not alarm control method. The method comprises the steps that the alarm duration T is preset; when it is judged that a person exists in front of the refrigerator door, the alarm duration is prolonged to be T + Delta; when it is judged that no person exists in front of the refrigerator door, the tightening alarm duration is Tmin; and after the refrigerator door is opened, if the duration exceeds the currently executed alarm duration, giving an alarm. Scenarized dynamic thresholds are achieved, human body existence and door body state two-dimensional threshold trigger logic is achieved, accurate recognition of abnormal scenes is improved through cooperation of multiple sensors, graded early warning and active intervention are achieved, alarm failure is avoided, the accuracy and timeliness of refrigerator door alarm are improved, and the method is suitable for being used for various refrigerator doors and has wide application prospects. The overall control logic is simple, and the operation reliability is high.

Description

Technical Field

[0001] This invention relates to the field of refrigerator control technology. Background Technology

[0002] Current household refrigerator alarms have a fixed duration threshold (most refrigerators default to 30 seconds to 1 minute). When the refrigerator door is opened and the fixed threshold time is reached, the buzzer will sound an alarm. This threshold is usually set by the refrigerator manufacturer.

[0003] However, the actual scenarios in which users open the door vary greatly, which can lead to an alarm threshold that is "too long": for example, forgetting to close the door (such as leaving in a hurry and closing the door behind, or a child accidentally opening the door and not closing it properly), if the threshold is fixed at 1 minute, a large amount of cold air will leak out of the refrigerator, causing the compressor to work overload, or foreign objects (such as pets or insects) will enter the refrigerator, or the food will spoil.

[0004] Currently, there are also control methods that employ big data analysis. For example, the published document with authorization announcement number CN113983738B, application announcement date August 18, 2023, and patent title "A Refrigerator and a Door Opening Alarm Control Method for a Refrigerator," discloses a method that, when receiving a door opening signal from the door opening / closing detection device, obtains the average door opening time of the refrigerator. The average door opening time is calculated in real-time based on the refrigerator's historical door opening / closing data. Based on the average door opening time, the current door opening alarm time is calculated. A door opening alarm timer is initiated, and if no door closing signal from the door opening / closing detection device is received after the alarm time, the alarm device is controlled to send an alarm message.

[0005] However, the overall control method is too complicated, especially when used in public places. Historical door opening and closing data cannot accurately reflect the usage status. Therefore, it is necessary to design a simpler and more reliable refrigerator door alarm method and system. Summary of the Invention

[0006] The present invention aims to address the problem of excessively long fixed threshold time for refrigerator alarms by implementing a refrigerator door opening threshold time design method and system, which solves problems such as "alarm delay, cold air leakage, food spoilage, and increased energy consumption" caused by excessively long fixed threshold time for refrigerator alarms.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is: a refrigerator door-open alarm control method, characterized in that:

[0008] Preset alarm duration T; (The value is determined by the manufacturer, ranging from 20 to 60 seconds, with a default value of 30 seconds);

[0009] If someone is detected in front of the refrigerator door, the alarm duration is extended by T+Delta.

[0010] When no one is detected in front of the refrigerator door, the alarm duration is tightened to T_min (value range 5-20 seconds, initial default value 10s).

[0011] If the refrigerator door is opened and the duration exceeds the currently set alarm duration, an alarm will be triggered.

[0012] In the extended alarm duration T+Delta, Delta is a real-time variable value. When someone is continuously detected, the Delta duration is increased. Delta has a preset upper limit limit Delta_max; (based on experience, the Delta_max value range is set to 3-8 minutes, and the default value is set to 5 minutes).

[0013] The range of alarm duration T+Delta is: T_total = min (T + k×t_person, T +Delta_max);

[0014] Where k is a user-defined coefficient, and t_person is the duration of human existence.

[0015] When the refrigerator door is opened, the alarm starts when the status changes from "someone is at the door" to "no one is at the door". If the timer exceeds the set time, it is determined that no one is at the door. If the status changes back to "someone is at the door" within the set time, the alarm duration is reset to T+Delta, without interrupting the previous duration accumulation.

[0016] The angle range of the refrigerator door is defined according to its opening angle as: fully open and not closed tightly;

[0017] When the refrigerator door is opened, the refrigerator door status is "not closed properly";

[0018] Regardless of whether anyone is at the door, the alarm duration is tightened to T_min, and T_min takes the minimum value;

[0019] The T_min value has a selectable range (5-20 seconds). The specific value is dynamically adjusted based on the degree to which the refrigerator door is not closed tightly (such as the size of the gap) and the ambient temperature, and the value must not be less than 5 seconds (to avoid excessive shortening that could lead to false alarms).

[0020] The ambient temperature is predefined, ranging from high temperature to low temperature, and divided into high temperature environment, normal temperature environment, and low temperature environment;

[0021] When the alarm duration is T_min, environmental correction is performed, and the ambient temperature is obtained.

[0022] If the environment is high temperature, then T_min takes the minimum value;

[0023] If the environment is at room temperature, then T_min takes a value of 7-9 seconds;

[0024] If it is a low-temperature environment, T_min takes the maximum value;

[0025] When the alarm duration is T_min, the refrigerator door gap size correction is set to the first priority, and the environmental correction is set to the second priority.

[0026] The state of a refrigerator door not being closed properly can be categorized from the largest to the smallest gap, as follows: severely not closed, slightly not closed, and basically closed.

[0027] When the refrigerator door is not fully closed, the door gap size signal is acquired. If it is severely not closed, T_min is set to the minimum value. If it is slightly not closed, T_min is set to 7-9 seconds. If it is basically closed, the preset alarm duration T is executed. If environmental correction is required at the same time, a fine adjustment of ±2 seconds is required on the basic value. After the fine adjustment, T_min must meet the total range limit requirement of 5-20 seconds.

[0028] The refrigerator door-open alarm control method provides tiered early warning;

[0029] The first-level warning will issue a pre-alarm when the timer reaches half of the alarm duration, reminding the user through screen prompts and flashing indicator lights;

[0030] The second-level warning alerts the user by flashing an indicator light and using a moderate volume buzzer when the alarm duration is reached.

[0031] The third-level warning will alert the user by flashing the indicator light and sounding the buzzer at its loudest volume when the timer reaches twice the alarm duration and the refrigerator door is still not closed. If the refrigerator is connected to WIFI, it will also send an alarm message to the user's mobile phone via WIFI.

[0032] In the second and third level warnings, the alarm will stop when the refrigerator door is closed.

[0033] When the refrigerator door is closed, if the difference between the maximum and minimum pressure values ​​of the miniature pressure sensor on the door frame exceeds a set threshold, an alarm will be triggered indicating that the seal is aging or food is stuck.

[0034] If the temperature in the freezer or refrigerator compartment exceeds the set threshold, an alarm will be triggered.

[0035] If the self-test determines that the radar is faulty, a fault prompt will be issued. At the same time, the dynamic alarm control method will be turned off and switched to the fixed threshold alarm mode. When the refrigerator door is opened, if the duration exceeds the preset basic alarm duration T (default 30 seconds), an alarm will be triggered.

[0036] A refrigerator door-open alarm control system includes a main control module connected to a door status detection module to obtain the refrigerator door's open / closed status information.

[0037] The main control module connects to and outputs alarm signals to the alarm execution module.

[0038] The main control module connects to and acquires information about obstacles in front of the refrigerator collected by the radar module.

[0039] The main control module is connected to the storage module and executes the refrigerator door-open alarm control method as described in claims 1-8, which is stored in the storage module.

[0040] The radar module uses millimeter-wave radar to monitor a preset area of ​​1-3 meters in front of the refrigerator door, with a detection angle of ±60°. The radar module is installed on the refrigerator door or refrigerator door frame.

[0041] The system is equipped with a power module, which supplies power to the main control module. The main control module is connected to the user interaction module and the refrigerator main control board linkage interface.

[0042] The door status detection module is equipped with a Hall sensor installed at the hinge of the refrigerator door. The Hall sensor collects the opening angle of the refrigerator door and is used to determine whether the refrigerator door is "fully open" or "not closed tightly" when it is open.

[0043] The door status detection module adds one miniature pressure sensor to each of the four corners of the refrigerator door frame;

[0044] The system is equipped with an environmental sensor module, which is connected to and outputs sensing signals to the main control module. The environmental sensor module is a temperature sensor that collects ambient temperature and is installed on the outside of the refrigerator door frame.

[0045] This invention implements scenario-based dynamic thresholds, achieving dual-dimensional threshold triggering logic based on human presence and door status. It utilizes multi-sensor collaboration to improve the accurate identification of abnormal scenarios, and provides tiered early warning and proactive intervention to prevent alarm failure. This enhances the accuracy and timeliness of refrigerator door alarms and is applicable to various types of refrigerator doors. The overall control logic is simple and the operation is highly reliable. Attached Figure Description

[0046] The following is a brief explanation of the content represented by each figure in this specification:

[0047] Figure 1 This is a diagram of the architecture of a refrigerator door-open alarm control system. Detailed Implementation

[0048] The following description, with reference to the accompanying drawings, details the specific implementation of the present invention, including the shape and structure of each component, the relative positions and connections between the parts, the function and working principle of each part, the manufacturing process, and the operation and use methods, to help those skilled in the art to have a more complete, accurate, and in-depth understanding of the inventive concept and technical solution of the present invention.

[0049] like Figure 1 As shown, the refrigerator door-open alarm control system mainly includes the following modules:

[0050] Power module:

[0051] Function: Provides stable power supply for the entire system, adapts to the system's 12V DC power supply environment, supports wide voltage input (9-15V), and ensures stable operation of low-power modules such as radar and MCU.

[0052] Main control module (core computing unit);

[0053] Functions: Receives door status and radar detection data, performs dynamic alarm duration calculation (T+Delta), controls the start and stop of the alarm module, and stores parameter configurations.

[0054] Door status detection module;

[0055] Function: Accurately identifies the "open / closed" state of the refrigerator door, providing a trigger point for alarm duration calculation. A Hall effect sensor is commonly used.

[0056] The door status detection module can also use Hall sensors installed at the refrigerator door hinges. The Hall sensors collect the opening angle of the refrigerator door, obtaining not only the open / closed status data but also the opening angle. By pre-defining the opening angle, it can be determined whether the refrigerator door is "fully open" or "not fully closed". In addition, a miniature pressure sensor can be added to each of the four corners of the refrigerator door frame. The miniature pressure sensors can collect the door's open / closed status, providing redundancy with the Hall sensors and serving as mutual verification mechanisms. In case of a fault, the sensor can be compared to determine the fault.

[0057] Millimeter-wave radar module (key component for user detection);

[0058] Function: Continuously monitors the presence of a human body in a preset area (1-3 meters, ±60° detection angle) in front of the refrigerator door, and outputs a human presence signal and duration.

[0059] Alarm execution module;

[0060] Function: Executes "immediate alarm" or "delayed alarm" according to MCU instructions, providing visual and audible prompts.

[0061] Storage module;

[0062] Functions: Stores preset alarm duration T, Delta calculation coefficient, radar detection parameters, and other configurations;

[0063] User interaction module (optional, to improve usability);

[0064] Functions: Allows users to manually adjust the preset alarm duration T (e.g., adjustable from 30 seconds to 5 minutes), provides access to alarm history records, and can display alarm events such as compressor failure and worn-out sealing strips.

[0065] Environmental sensor module;

[0066] The environmental sensor module is used to collect ambient temperature to assist in correcting the refrigerator door-open alarm control method. The environmental sensor module is connected to and outputs sensing signals to the main control module. The environmental sensor module is a temperature sensor that collects ambient temperature and is installed on the outside of the refrigerator door frame. In addition, the environmental sensor module also includes a temperature sensor inside the refrigerator, which collects the temperature inside the refrigerator for its own temperature regulation and control, and can also be used as correction data for the door-open alarm control method.

[0067] The specific implementation method for the refrigerator door-open alarm control is described below:

[0068] Threshold tightening logic design (core algorithm);

[0069] Basic rules: The alarm duration is preset to T (e.g., 30 seconds by default), but the threshold can only be extended by T+Delta when "the radar detects someone in front of the door"; if "the radar detects no one in front of the door", the threshold is directly tightened to "minimum safety threshold T_min (e.g., 10 seconds)" and cannot be extended.

[0070] Example 1: User forgets to close the door and leaves (no one is at the door) → After the door is opened, the radar immediately determines "no one is there" → The alarm threshold automatically switches to T_min=10 seconds → If the door is not closed after 10 seconds, the alarm is triggered to prevent cold air from leaking out for a long time.

[0071] Example 2: User organizes ingredients (someone is at the door) → Threshold is dynamically extended by T+Delta → This neither interferes with the operation nor causes anomalies due to an excessively long threshold.

[0072] Delta upper limit limit: Even if someone is in front of the door, a maximum limit for Delta is set (e.g., Delta_max=5 minutes) to prevent the threshold from being extended indefinitely due to people staying in the door for a long time (e.g., forgetting to close the door but standing in front of it), thus balancing experience and energy consumption.

[0073] Formula optimization: T_total = min (T + k×t_person, T + Delta_max), where k=1 (adjustable), Delta_max=5 minutes.

[0074] Door status is subdivided: distinguishing between "fully open" and "not fully closed" for precise tightening.

[0075] By optimizing the signal accuracy of the door status detection module, the door status is further subdivided, and different tightening thresholds are set for different statuses:

[0076] Fully open (Hall sensor output high level for ≥50ms, distance between door and door frame ≥5cm):

[0077] If no one is at the door → Threshold T_min = 10 seconds (rapid alarm to reduce cold air leakage);

[0078] If someone is in front of the door → press T+Delta to extend the time, but Delta_max = 5 minutes.

[0079] Not fully closed (Hall sensor output level fluctuates, distance between door and frame is 1-5cm, or sensor signal is intermittent):

[0080] Regardless of whether anyone is at the door → immediately tighten the threshold to T_min=5 seconds (when the door is not closed tightly, cold air continues to leak and the user may not notice, so a quick reminder is needed);

[0081] Trigger a "weak alarm" (such as slow LED flashing + low-volume beep) to prevent users from noticing that the door is not closed properly.

[0082] Accurate determination of unattended status (avoiding unintended tightening)

[0083] To prevent the radar from mistakenly identifying "no one" and causing the threshold to be tightened inappropriately (e.g., a user briefly leaves the door to retrieve something), the following additional judgment conditions are added:

[0084] The radar detects "no one" for a duration of ≥2 seconds (to avoid false alarms of instantaneous departure);

[0085] If a user returns to the door after a brief absence (≤2 seconds), the threshold is restored to T+Delta, without interrupting the previous duration accumulation;

[0086] If the user leaves for ≥2 seconds → immediately switch the threshold to T_min and restart the timer (e.g., if the door was open for 20 seconds, the timer will be reset to 0 after leaving, and an alarm will be triggered if the door is not closed after 5 seconds).

[0087] To address the "excessively long threshold" issue, the system incorporates additional environmental sensors to dynamically adjust thresholds based on ambient temperature and humidity. This allows for the addition of low-cost environmental sensors to the hardware system and further optimize the system by adjusting and tightening thresholds according to environmental temperature and humidity. (This adapts to different seasons and regional usage scenarios.)

[0088] When the ambient temperature is ≥25℃ (summer / high temperature environment): the cold air leakage speed is fast, T_min=8 seconds (shorter threshold, fast alarm);

[0089] When 10℃ < ambient temperature < 25℃ (spring and autumn): T_min = 10 seconds (default tightening threshold);

[0090] When the ambient temperature is ≤10℃ (winter / low temperature environment): the cold air leakage rate is slow, T_min=15 seconds (appropriately relaxed, but still shorter than the default T=30 seconds, to avoid the threshold being too long).

[0091] Hardware adaptation: The sensor is installed on the outside of the refrigerator door frame (to avoid being affected by the low temperature inside the refrigerator), and connects to the MCU via the I2C interface to transmit ambient temperature data in real time for dynamic threshold adjustment.

[0092] 2. Added door gap detection (reusing Hall sensor and optimizing signal processing)

[0093] Logic design: The size of the door gap is determined by the signal strength of the Hall sensor (the larger the gap, the farther the magnet is from the sensor, and the weaker the signal).

[0094] Gaps ≥ 3cm (severely not closed tightly): T_min = 5 seconds;

[0095] Gaps 1-3cm (slightly not closed tightly): T_min = 8 seconds;

[0096] Gaps < 1cm (basically closed): Tightening is not triggered, maintaining the normal threshold.

[0097] Tiered early warning system combined with proactive intervention avoids losses caused by excessively long thresholds. Even if the threshold is tightened, if the user still does not close the door, the "tiered early warning" system will strengthen the reminder. At the same time, the proactive intervention function will reduce air leakage and energy loss, solving the problem of "users ignoring the alarm".

[0098] Tiered early warning design (adapted to alarm execution module):

[0099] Level 1 (Warning): When the door is open for 50% of T_min (e.g., when T_min = 10 seconds, at 5 seconds) → the LED yellow light flashes slowly (without a buzzer), and the display screen displays "Door not closed properly, please close it in time" (a gentle reminder to avoid disturbing others);

[0100] Level 2 (Alarm): When the door is open for T_min (e.g., 10 seconds) → LED red light flashes rapidly + buzzer sounds intermittently at low volume (core reminder), and at the same time, the refrigerator main control board is linked to reduce the compressor power (reduce energy consumption);

[0101] Level 3 (Strong Alarm + Active Intervention): When the door is open for 2×T_min (e.g., 20 seconds) → the buzzer sounds continuously at a high volume, the LED red light stays on, and at the same time, an alarm message (e.g., "Refrigerator door has been open for 20 seconds, please close it") is pushed to the user's mobile phone via the refrigerator's Wi-Fi module (an ESP8266 module can be added, which is low cost).

[0102] If the refrigerator door is supported by electric assist function, it can trigger the "gentle closing" action (such as pulling the door through a micro motor, provided that the refrigerator hardware supports it) or lock the refrigerator door (to prevent children from accidentally opening it and being unable to close it).

[0103] Added a special inspection for "door not closed properly" (requires hardware optimization);

[0104] For situations where the door is not closed properly due to aging door seals or food getting stuck (a scenario most easily overlooked when the threshold is too high), supplementary detection is provided:

[0105] Hardware supplement: Add one miniature pressure sensor (such as FSR402) to each of the four corners of the refrigerator door frame. When the door is closed, the pressure sensor is squeezed (outputs a high level). When the door is not closed tightly, the sensor in one corner has no pressure (outputs a low level).

[0106] Logic design: If any pressure sensor outputs a low level (indicating the door is not closed properly), and the radar detects no one, the first-level warning is triggered directly (after 5 seconds), and the second-level alarm is triggered after 10 seconds, without waiting for the original long threshold.

[0107] A fallback solution: dual upper limits of time and environment to prevent the threshold from being extended indefinitely;

[0108] Even if the above judgment logic malfunctions (such as radar failure), a "hard upper limit" is used as a fallback to prevent the threshold from becoming too long:

[0109] Absolute time limit: Regardless of whether there are people or the environment, set the maximum alarm duration T_max (e.g., 3 minutes) → If the door is open for more than T_max, a strong alarm will be forcibly triggered (even if the radar misjudges that someone is there) to prevent the unlimited leakage of cold air;

[0110] Environmental threshold limit: The temperature inside the cabinet is detected by a temperature sensor. If the refrigeration temperature exceeds 8℃ (or the freezing temperature exceeds -10℃), an alarm will be triggered immediately, regardless of the duration of the door being opened or the state of the person (the food is already at risk of spoilage and there is no need to wait for the threshold).

[0111] Radar fault fallback: If the radar module fails (no data output), it will automatically switch to "fixed short threshold mode" (T=15 seconds), and the LED yellow light will remain on to indicate "radar fault" to avoid the threshold being too long due to the fault.

[0112] This invention relates to the design of a refrigerator door opening alarm threshold time, and can be applied to home and supermarket scenarios where users forget to close the door and the alarm threshold time has not yet been reached.

[0113] In summary, the present invention has the following advantages:

[0114] 1. Core logic innovation: Achieving "scenario-based dynamic thresholds";

[0115] It pioneered a dual-dimensional threshold triggering logic based on "human presence + gate state";

[0116] Traditional fixed thresholds rely solely on "door opening time" as the sole criterion for judgment. In contrast, this solution utilizes the human detection capabilities of millimeter-wave radar to use "whether someone is in front of the door" as the core trigger condition for threshold adjustment. When someone is in front of the door, the threshold can be dynamically extended, while it automatically tightens to a safe short threshold when no one is present. This completely solves the dual pain points of "alarm delay caused by excessively long thresholds when the door is left open" and "false alarms caused by excessively short thresholds during normal operation," achieving precise adaptation of "long when it should be long, and short when it should be short."

[0117] A balanced design between Delta dynamic calculation and upper limit constraints;

[0118] The innovative algorithm uses a dynamic coefficient of "Delta = k×t_person" to make the extension duration proportional to the duration of human presence. At the same time, it sets an upper limit of Delta_max (e.g., 5 minutes), which not only meets the needs of users for long-term operations (such as organizing food), but also avoids the threshold from being extended indefinitely due to prolonged human presence. This balances user experience with refrigerator energy consumption and food preservation needs, and solves the rigid problem of the traditional fixed threshold.

[0119] 2. Technological Innovation: Multi-sensor collaboration enhances the accurate identification of abnormal scenarios;

[0120] Door status detailing technology accurately locates hidden anomalies such as "not fully closed";

[0121] Breaking away from the traditional binary judgment of "door open / closed", this system analyzes the signal strength of Hall sensors to subdivide multiple states such as "fully open", "slightly not closed", and "severely not closed". Different tightening thresholds are matched for different states (e.g., T_min=5 seconds when severely not closed). This solves the industry pain point that traditional fixed thresholds cannot identify the hidden abnormality of "door not closed", which leads to continuous air leakage.

[0122] Environmentally adaptive threshold adjustment to suit different usage scenarios;

[0123] A new low-cost temperature sensor was added, which dynamically adjusts the threshold according to the ambient temperature (e.g., T_min=8 seconds in high summer temperatures and T_min=15 seconds in low winter temperatures). This allows the threshold to not only adapt to user behavior but also to environmental changes. In high-temperature environments, it provides a rapid alarm to reduce cold air leakage, while in low-temperature environments, it appropriately relaxes the threshold to improve the user experience, achieving collaborative adaptation between "human-machine-environment".

[0124] 3. User experience innovation: Tiered early warning + proactive intervention to avoid alarm failure;

[0125] A multi-level, tiered early warning mechanism balances the effectiveness of alerts with user experience.

[0126] The innovative design features a three-tiered alert system: "early warning - alarm - strong alarm" (e.g., 5-second yellow light warning, 10-second red light low-volume alarm, 20-second high-volume alarm + mobile push notification). This replaces the traditional single forced alarm method, avoiding sudden noise disturbances (such as when retrieving ingredients at night) and enhancing user perception through progressive reminders. It solves the pain point of traditional alarms being either "not sounding at all or extremely loud."

[0127] Radar failure fallback design ensures system reliability;

[0128] When the millimeter-wave radar module malfunctions, the system automatically switches to "fixed short threshold mode" (T=15 seconds) and simultaneously indicates the fault via a yellow LED light. This not only prevents the threshold from becoming invalid due to radar failure but also ensures the normal operation of the refrigerator's basic alarm function, thus improving the engineering practicality and reliability of the solution.

[0129] The present invention has been described above by way of example with reference to the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any non-substantial improvements made using the inventive concept and technical solution of the present invention, or the direct application of the inventive concept and technical solution of the present invention to other occasions without modification, are all within the protection scope of the present invention.

Claims

1. A refrigerator door-open alarm control method, characterized in that: Preset alarm duration T; If someone is detected in front of the refrigerator door, the alarm duration is extended by T+Delta. If no one is detected in front of the refrigerator door, tighten the alarm duration to T_min; If the refrigerator door is opened and the duration exceeds the currently set alarm duration, an alarm will be triggered.

2. The refrigerator door-open alarm control method according to claim 1, characterized in that: In the extended alarm duration T+Delta, Delta is a real-time variable value. When it is continuously determined that someone is present, the Delta duration is increased. Delta has a preset upper limit limit Delta_max. The range of alarm duration T+Delta is: T_total = min (T + k×t_person, T + Delta_max); Where k is a user-defined coefficient, and t_person is the duration of human existence.

3. The refrigerator door-open alarm control method according to claim 2, characterized in that: When the refrigerator door is opened, the alarm starts when the status changes from "someone is at the door" to "no one is at the door". If the timer exceeds the set time, it is determined that no one is at the door. If the status changes back to "someone is at the door" within the set time, the alarm duration is reset to T+Delta, without interrupting the previous duration accumulation.

4. The refrigerator door-open alarm control method according to claim 3, characterized in that: The angle range of the refrigerator door is defined according to its opening angle as: fully open and not closed tightly; When the refrigerator door is opened, the refrigerator door status is "not closed properly"; Regardless of whether anyone is at the door, the alarm duration is tightened to T_min, and T_min takes the minimum value; The value range of T_min is selectable.

5. The refrigerator door-open alarm control method according to any one of claims 1-4, characterized in that: The ambient temperature is predefined, ranging from high temperature to low temperature, and divided into high temperature environment, normal temperature environment, and low temperature environment; When the alarm duration is T_min, environmental correction is performed, and the ambient temperature is obtained. If the environment is high temperature, then T_min takes the minimum value; If the environment is at room temperature, then T_min takes a value of 7-9 seconds; If it is a low-temperature environment, T_min takes the maximum value; When the alarm duration is T_min; Refrigerator door gap size correction is the first priority, and environmental correction is the second priority.

6. The refrigerator door-open alarm control method according to claim 5, characterized in that: The state of a refrigerator door not being closed properly can be categorized from the largest to the smallest gap, as follows: severely not closed, slightly not closed, and basically closed. When the refrigerator door is not fully closed, the door gap size signal is acquired. If it is severely not fully closed, T_min is set to the minimum value. If it is slightly not fully closed, T_min is set to 7-9 seconds. If it is basically closed, the preset alarm duration T is executed.

7. The refrigerator door-open alarm control method according to claim 6, characterized in that: The refrigerator door-open alarm control method provides tiered early warning; The first-level warning will issue a pre-alarm when the timer reaches half of the alarm duration, reminding the user through screen prompts and flashing indicator lights; The second-level warning alerts the user by flashing an indicator light and using a moderate volume buzzer when the alarm duration is reached. The third-level warning will alert the user by flashing the indicator light and sounding the buzzer at its loudest volume when the timer reaches twice the alarm duration and the refrigerator door is still not closed. If the refrigerator is connected to WIFI, it will also send an alarm message to the user's mobile phone via WIFI. In the second and third level warnings, the alarm will stop when the refrigerator door is closed.

8. The refrigerator door-open alarm control method according to claim 1 or 7, characterized in that: When the refrigerator door is closed, if the difference between the maximum and minimum pressure values ​​of the miniature pressure sensor on the door frame exceeds a set threshold, an alarm will be triggered indicating that the seal is aging or food is stuck. If the temperature in the freezer or refrigerator compartment exceeds the set threshold, an alarm will be triggered. If the self-test determines that the radar is faulty, a fault prompt will be issued. At the same time, the dynamic alarm control method will be turned off and switched to the fixed threshold alarm mode. When the refrigerator door is opened, if the duration exceeds the preset basic alarm duration T, an alarm will be triggered.

9. A refrigerator door-open alarm control system, the system comprising a main control module, the main control module being connected to a door status detection module to obtain refrigerator door open / closed status information. The main control module connects to and outputs alarm signals to the alarm execution module. The main control module connects to and acquires information about obstacles in front of the refrigerator collected by the radar module. Its features are: The main control module is connected to the storage module and executes the refrigerator door-open alarm control method as described in claims 1-8, which is stored in the storage module.

10. The refrigerator door-open alarm control system according to claim 9, characterized in that: The radar module uses millimeter-wave radar to monitor a preset area of ​​1-3 meters in front of the refrigerator door, with a detection angle of ±60°. The radar module is installed on the refrigerator door or refrigerator door frame. The system is equipped with a power module, which supplies power to the main control module. The main control module is connected to the user interaction module and the refrigerator main control board linkage interface. The door status detection module is equipped with a Hall sensor installed at the hinge of the refrigerator door. The Hall sensor collects the opening angle of the refrigerator door and is used to determine whether the refrigerator door is "fully open" or "not closed tightly" when it is open. The door status detection module adds one miniature pressure sensor to each of the four corners of the refrigerator door frame; The system is equipped with an environmental sensor module, which is connected to and outputs sensing signals to the main control module. The environmental sensor module is a temperature sensor that collects ambient temperature and is installed on the outside of the refrigerator door frame.

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