A coverless fan active protection method and a coverless fan

Abstract

The application discloses a coverless fan active protection method and a coverless fan. The coverless fan active protection method comprises the following steps: a DTOF sensor is fixedly arranged on the body of the fan, target distance information is collected in real time through the DTOF sensor, and the speed of the target is calculated when the target distance is less than or equal to a boundary distance; a controller receives the target distance information through the DTOF sensor and generates a level protection instruction to actively protect; the controller evaluates the target distance information according to a preset level exit condition, and when the target distance information matches the preset level exit condition, the fan is controlled to execute a state before protection. The system-level non-contact safety protection of the coverless fan is realized, the protection safety distance can be adjusted, and double-channel parallel detection is realized.

Description

Technical Field

[0001] This invention relates to the field of active protection technology for hoodless fans, specifically, to an active protection method for hoodless fans and a hoodless fan. Background Technology

[0002] Currently, with the development and prosperity of the consumer electronics market, people have higher requirements for the user experience and appearance of fans. In order to meet market demand and cost requirements, manufacturers have designed bladeless fans, which eliminate the cost of covers and the obstruction of airflow by covers, and have a more innovative appearance than traditional covered fans.

[0003] The resulting problem is that, due to the exposed blades, the high-speed rotation of the blades could cause injury to people if used improperly. Therefore, this invention patent aims to solve the problem of how to achieve active protection through electrical system design to prevent the rotating fan blades from causing injury to people or other objects. Summary of the Invention

[0004] To address at least one of the aforementioned technical problems, embodiments of the present invention provide an active protection method for a fan without a shield, comprising: a DTOF sensor fixedly mounted on the fan body, and real-time acquisition of target distance information via the DTOF sensor, and calculation of target speed when the target distance is less than or equal to a boundary distance; the fan controller receiving the target distance information and target speed via the DTOF sensor and performing a protection level assessment, including: when the real-time target distance information interruption duration exceeds a first threshold, or when the number of consecutive times the target distance is less than zero exceeds or equal to a preset number, determining a sensor fault and generating a level four protection command, the level four protection command being used to control the fan to output a first-level speed and lock the fan speed, output a level four protection prompt message, and simultaneously store the pre-protection state; when the target distance is less than the boundary distance and the target speed is less than or equal to a boundary distance, the fan controller receives the target distance information and target speed via the DTOF sensor and performs a protection level assessment, including: when the real-time target distance information interruption duration exceeds a first threshold, or when the number of consecutive times the target distance is less than zero exceeds a preset number, determining a sensor fault and generating a level four protection command, the level four protection command being used to control the fan to output a first-level speed and lock the fan speed, output a level four protection prompt message, and simultaneously store the pre-protection state; when the target distance is less than the boundary distance and the target speed is less than or equal to a boundary distance, the fan controller receives the target distance information and target speed via the DTOF sensor and performs a protection level assessment, including: ... real-time target distance information interruption duration exceeds a first threshold, or when the number of consecutive times the target distance is less than or equal to a preset number, determining a sensor fault and generating a level four protection command, the fan controller receives the target distance information and target speed via the DTOF sensor and performs a protection level assessment, including: when the When the speed exceeds the threshold, a Level 1 protection command is generated. This command cuts off the main power supply to the fan motor, outputs a Level 1 protection warning message, and stores the pre-protection state. When two consecutive target distances are greater than the first distance but less than or equal to the second distance, a Level 2 protection command is generated. This command controls the fan to output a first-level speed and locks the fan speed, outputs a Level 2 protection warning message, and stores the pre-protection state. When two consecutive target distances are greater than the second distance but less than or equal to the boundary distance, a Level 3 protection command is generated. This command controls the fan to output a second-level speed and locks the fan speed, outputs a Level 3 protection warning message, and stores the pre-protection state. The controller evaluates the target distance information based on preset exit conditions. When the target distance information matches the preset exit conditions, the controller controls the fan to execute the pre-protection state.

[0005] Preferably, the controller locks the button gear command in response to the first-level protection command, stores the button gear command in response to the second-level, third-level and fourth-level protection commands, and executes the stored button gear command according to the preset level exit conditions.

[0006] Preferably, the controller locks the button command when the duration of the button command exceeds the button jamming time threshold, and outputs a button fault prompt message.

[0007] Preferably, when the target distance is less than the first distance and the continuous static time is greater than or equal to the second threshold, a physical button operation mode instruction is generated. The physical button operation mode instruction allows the user to control the fan to stop swinging and the motor to stop. In response to the target distance being greater than the boundary distance and the target distance increasing three times consecutively by a distance greater than or equal to the distance threshold, the motor is started and the swing angle is restored according to the button position input by the user.

[0008] Preferably, when the target distance is less than the first distance, the current fan mode is evaluated, and when the current fan mode is a non-physical button operation mode command, a first-level protection command is generated.

[0009] Preferably, the controller receives Bluetooth commands through the Bluetooth module, locks the Bluetooth mode command in response to the first-level protection command, stores the Bluetooth mode command in response to the second-level, third-level and fourth-level protection commands, and executes the Bluetooth mode command according to the preset exit conditions.

[0010] Preferably, when the maximum difference in target distance within the third threshold is less than or equal to the steady state threshold, the target acceleration is calculated, and when the target acceleration is less than the sitting acceleration, the swing motor is controlled to execute the sitting mode. When the target acceleration is greater than the fitness acceleration, the swing motor is locked to execute the fitness mode; otherwise, the full swing mode is executed.

[0011] Preferably, the controller receives temperature and humidity information by connecting to a temperature sensor and a humidity sensor, receives physiological data via a Bluetooth module, and generates environmental mode commands based on the temperature, humidity, and physiological data. The environmental mode commands include a comfortable environmental mode command, an overheating environmental mode command, and an overcooling environmental mode command. The comfortable environmental mode command is used to maintain the current fan speed and oscillation angle, the overheating environmental mode command is used to increase the speed by one level, and the overcooling environmental mode command is used to decrease the speed by one level. In fitness mode, it responds to the overheating environmental mode command by increasing the speed by two levels, and locks the speed when the protection level is level two and level four. When the protection level is level three, the highest speed is set to level three.

[0012] Preferably, the step of the fan controller receiving target distance information and target speed through a DTOF sensor and performing a protection level assessment based on the protection level assessment threshold further includes: the fan controller receiving target physiological data through a Bluetooth module, the target physiological data including target height, and determining the protection level assessment threshold based on the target height; the fan controller receiving target distance information and target speed through a DTOF sensor and performing a protection level assessment based on the protection level assessment threshold.

[0013] On the other hand, a shieldless fan is provided, including a controller, a DTOF sensor, a temperature sensor, a humidity sensor, and a Bluetooth module. The controller receives target distance information through the DTOF sensor, ambient temperature through the temperature sensor, ambient humidity through the humidity sensor, and user physiological data through the Bluetooth module. The controller executes the active protection method for the shieldless fan as described above based on the received target distance information, ambient temperature, ambient humidity, and user physiological data. When the blades are transparent, the DTOF sensor is located behind the blades; when the blades are opaque, the DTOF sensor is located in front of the blades.

[0014] The active protection method for a fan without a cover according to the present invention has the following technical effects: by using a DTOF sensor for protection, the fan can be protected with only a single sensor in extreme cases. By optimizing the installation position of the DTOF sensor, the effect of not affecting the product appearance and achieving the optimal number of sensors is achieved.

[0015] The active protection method using the covered fan achieves system-level contactless safety protection for the fanless system. It also allows for adjustable safety distance and dual-channel parallel detection, resulting in a protection reliability of over 98%. It provides reliable active safety protection against the approach of personnel or objects.

[0016] By employing an optical sensor based on direct time-of-flight (DTOF) measurement and predicting human posture through logical judgment, while improving the working logic of the fan controller to provide non-contact electrical system safety protection, it has the advantages of fast response, high reliability, and less susceptibility to environmental factors.

[0017] By applying Bluetooth and sensor technologies to acquire and process digital data such as human body data and environmental status perception, and then making comprehensive logical judgments to intelligently control the fan, intelligent fan control is achieved to meet user requirements. Attached Figure Description

[0018] To better understand the above and other objects, features, advantages, and functions of the present invention, reference can be made to the embodiments shown in the accompanying drawings. The same reference numerals in the drawings refer to the same parts. Those skilled in the art should understand that the drawings are intended to schematically illustrate preferred embodiments of the invention and do not limit the scope of the invention in any way; the parts in the drawings are not drawn to scale.

[0019] Figure 1 The diagram shown is a block diagram of a shieldless fan structure according to an embodiment of this application;

[0020] Figure 2 The diagram shown is a frameless positional schematic of the DTOF sensor of the shawl-less fan according to an embodiment of this application.

[0021] Figure 3 The diagram shows the framed position of the DTOF sensor for the hoodless fan according to an embodiment of this application. Detailed Implementation

[0022] The exemplary embodiments of this disclosure are described below with reference to the accompanying drawings, including various details of the embodiments to aid understanding, and should be considered merely exemplary. Therefore, those skilled in the art will recognize that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of this disclosure. Similarly, for clarity and brevity, descriptions of well-known functions and structures are omitted in the following description.

[0023] The term "comprising" and its variations as used herein signify open inclusion, i.e., "including but not limited to". Unless otherwise stated, the term "or" means "and / or". The term "based on" means "at least partially based on". The terms "one example embodiment" and "one embodiment" mean "at least one example embodiment". The term "another embodiment" means "at least one additional embodiment". The terms "first", "second", etc., may refer to different or the same objects. Other explicit and implicit definitions may also be included below.

[0024] To at least partially address one or more of the aforementioned problems and other potential issues, embodiments of this disclosure propose an embodiment of the present invention providing a shieldless fan, including a controller, a DTOF (direct time of flight) sensor, a temperature sensor, a humidity sensor, and a Bluetooth module. The controller receives target distance information via the DTOF sensor, ambient temperature via the temperature sensor, ambient humidity via the humidity sensor, and user physiological data via the Bluetooth module. The controller executes an active protection method for the shieldless fan based on the received target distance information, ambient temperature, ambient humidity, and user physiological data. When the blades are transparent, the DTOF sensor is positioned behind the blades; when the blades are opaque, the DTOF sensor is positioned in front of the blades.

[0025] Specifically, such as Figure 2 As shown, the installation location of the DTOF sensor is determined based on the fan structure and the coverage range of the sensor signal. Within the sensor's detectable distance range (not less than 2 meters), for frameless fans without a cover, when the blades are transparent, the DTOF sensor is installed in a fixed position behind the blades (e.g., Figure 2 (Point A in the middle). When the blade is not transparent, the DTOF sensor is installed on the underside of the blade in a non-rotating position (e.g., point A in the middle). Figure 2 (Point B in the diagram). This installation location is for illustrative purposes only; the actual number needs to be determined based on the sensor coverage angle and fan blade length. For example, a shadeless fan may include multiple DTOF sensors; when the blades are transparent, multiple DTOF sensors... Figure 2 The DTOF sensors are evenly distributed on the circumference where point A is located. The number of multiple DTOF sensors can be 2, 3, 4, etc.

[0026] like Figure 3 As shown, for a frameless fan without a cover, when the blades are transparent, the DTOF sensor is installed in a fixed position behind the blade (e.g., Figure 3 (Point A in the middle). When the blade is non-transparent, the DTOF sensor is mounted in a fixed position on the frame (e.g., ...). Figure 3 (Point B in the middle). This installation location is for illustrative purposes only; the actual number needs to be determined based on the sensor coverage angle and fan blade length.

[0027] like Figure 1As shown, the shadeless fan also includes a power module, which provides power and voltage conversion for the entire fan system. For example, when the external power supply voltage is AC 220V, the power module can output low-voltage DC power to supply other control modules. The DTOF sensor integrates the DTOF sensor and necessary control circuitry, calculating the distance / speed information of the detected object by measuring the phase difference between the emitted and received light rays. The fan controller receives external control signals (wired or wireless signals) to control the fan motor speed and direction. The motor controls the fan rotation; a brushless DC motor is commonly used. This patent does not limit the type of motor. Environmental sensors include temperature and humidity sensors for detecting ambient temperature and humidity. The detected object represents a person or other object that may be close to the fan.

[0028] The controller includes an active protection module, which controls the fan for active protection. The active protection levels are as follows: Level 1 protection: If the DTOF sensor detects an object rapidly approaching within the protection range (running state), the fan immediately stops and the power is cut off; if an object is detected approaching within 30cm, the fan immediately stops and the power is cut off (based on distance and running speed); Level 2 protection: If the DTOF sensor detects an object approaching within 50cm, the fan motor speed is reduced to level 1 and an alarm sounds; Level 3 protection: If the DTOF sensor detects an object approaching within 100cm, the fan motor speed is reduced to level 2 and a light alarm sounds; Level 4 protection: If the DTOF sensor fails, the fan motor outputs a fixed level 1, and a light alarm sounds. The active protection module detects that an object that entered the protection area has left via the DTOF sensor, maintains a safe time (software set), and then resumes its original operating state.

[0029] The controller also includes an environmental pattern recognition module, which identifies the current environmental pattern based on sensor data and generates corresponding environmental pattern commands. Comfortable environmental conditions include an ambient temperature of 22-26℃, humidity of 40%-60%, body temperature of 36.0-37.2℃, and heart rate of 60-90 beats / minute, maintained for a certain period (e.g., 5 seconds), which is determined to be a "comfortable state" and the current operating state is maintained. Overheating environmental conditions include: temperature > 26℃, humidity > 60%, body temperature > 37.2℃, and heart rate > 90 beats / minute, maintained for a certain period (e.g., 5 seconds), which is determined to be a "cooling-required state" and requires increasing the fan speed by one level.

[0030] The controller also includes a user status recognition module, used to identify the user's status and adjust the fan mode accordingly. For example, if the DTOF sensor reading is stable (±2cm) and the Bluetooth feedback indicates the target acceleration is stationary, it is determined that the user is sitting still, and the fan is oscillating at a certain angle around the user. If the DTOF sensor reading is stable (±2cm) and the Bluetooth feedback indicates the target is moving, it is determined that the user is exercising indoors, and the fan is directed to a specific point around the user. If the DTOF sensor reading is stable (±2cm) and the distance to the fan is less than 30cm, it is determined that the user is using the physical buttons to adjust the fan. After the user completes the physical button setting, the motor remains stationary within 30cm. Once the system detects the user moving away and reaches a safe distance of 100cm, the fan outputs according to the user's set speed.

[0031] The aforementioned unshielded fan undergoes system initialization via steps 1-6.

[0032] Step 1: Power on and perform self-test on the hardware.

[0033] After the fan controller is powered on, it automatically initializes the controller MCU, all sensors, Bluetooth module, motor drive, and alarm devices (buzzer / LED).

[0034] The self-test includes: testing the phase difference output of the DTOF sensor to verify the distance measurement function; verifying the validity of the measurement range by having the temperature and humidity sensor return initial environmental data; scanning and binding devices with the Bluetooth module to attempt to establish a connection; detecting the button level of the physical buttons to eliminate jamming faults; and verifying the motor response by having the motor drive output a small PWM signal.

[0035] Self-test result processing: When any of the DTOF sensor, Bluetooth module, temperature sensor, humidity sensor, physical button and motor drive malfunctions, a level 4 protection command is generated and the fault light is kept on.

[0036] When the self-test result is normal, the parameter loading process begins.

[0037] Step 2, load configuration parameters.

[0038] Read the pre-stored parameters from the EEPROM. The pre-stored parameters include: gear-speed mapping, time / threshold parameters, swing angle parameters, and the working status (gear / swing angle) before the last shutdown.

[0039] When powered on for the first time without any pre-stored parameters, the default parameters are loaded (initial setting 2, full swing angle ±60° air supply).

[0040] Step 3, initial state settings.

[0041] Motor speed: Initial gear (can be set according to user needs).

[0042] Swing angle mode: Default is full swing angle.

[0043] Alarm status: No alarm, LED gear indicator shows the current gear (2nd gear, green light is always on).

[0044] Record the initial state as "original working state" (for recovery after exiting protection mode).

[0045] Step 4: Bluetooth connection and data synchronization.

[0046] The Bluetooth module continuously scans for and binds to devices, successfully connecting within 30 seconds. It simultaneously receives heart rate, body temperature, and acceleration data, as well as Bluetooth level adjustment commands. Devices bound to the Bluetooth module include wearable devices such as wristbands and smart glasses, as well as smart mobile terminals such as smartphones and tablets.

[0047] If the connection fails within 30 seconds, the blue LED will flash as a warning (this does not affect the basic operation of the fan; the environmental condition is determined solely by temperature and humidity).

[0048] Step 5: Wait for the power-on command.

[0049] If the device was previously powered off, the fan will be in standby mode, with only the LED power indicator remaining on, and the motor will not start.

[0050] After receiving a power-on command via physical button or Bluetooth, start the motor (running in the initial gear / the gear before the last power-off).

[0051] Step 6: Enter the main loop.

[0052] After powering on, it enters the main loop of "data acquisition - logic judgment - action execution", with a loop period of 10ms (synchronized with the DTOF sampling frequency).

[0053] Step 7: Collect data synchronously from multiple sources and collect data at the set frequency.

[0054] The DTOF sensor samples at 100Hz, acquiring phase difference, detection area coordinates, and timestamps to calculate the original distance.

[0055] The temperature and humidity sensors sample at 1Hz, collecting ambient temperature (T_env) and relative humidity (H_env).

[0056] The Bluetooth module samples at 5Hz to collect user body temperature (T_user), heart rate (HR_user), acceleration (A_user), and Bluetooth mode adjustment commands.

[0057] The physical buttons are monitored in real time for button status (pressed / released), and the operation time is recorded.

[0058] Step 8, data preprocessing.

[0059] DTOF sensor data processing: Distance calculation, based on phase difference - raw distance - moving average filtering (average of 3 samples) - effective distance (D_eff, accurate to 1mm); Velocity calculation, instantaneous velocity V=|D_eff (n) - D_eff (n-1)| / 0.01s (Δt=10ms). Anomaly removal, removing invalid data where D_eff < 0cm or > 3m (maximum detection range of the sensor).

[0060] Physiological and environmental data processing: Body temperature / heart rate / temperature and humidity are averaged by three consecutive samples, and outliers are removed (e.g., body temperature >42℃ or <35℃, heart rate >150 or <40 beats / min).

[0061] Button handling includes physical button debounce protection (press and hold for 50ms before confirming) to prevent accidental touches;

[0062] Bluetooth commands are processed by verifying their integrity using the frame header and checksum, and invalid commands are discarded.

[0063] Step 9, Data Validation Marking.

[0064] Data is marked with a status, which includes whether the data is valid or invalid.

[0065] Invalid scenarios: DTOF has no data, physiological data is invalid when Bluetooth connection is lost, and button commands are invalid when the button is stuck.

[0066] Processing rule: Invalid data will not be included in the corresponding logical judgment (e.g., when there is no physiological data, the environmental state depends only on temperature and humidity).

[0067] An active protection method for a fan without a cover includes: a fan controller receiving target physiological data, including target height, via a Bluetooth module, and determining a protection level assessment threshold based on the target height; a DTOF sensor fixedly mounted on the fan body, and real-time acquisition of target distance information via the DTOF sensor, and calculation of target speed when the target distance is less than or equal to a boundary distance; the fan controller receiving target distance information and target speed via the DTOF sensor and assessing the protection level based on the protection level assessment threshold, including: when the real-time target distance information is interrupted for a duration greater than a first threshold, or when the number of consecutive times the target distance is less than zero is greater than or equal to a preset number, determining a sensor fault and generating a level four protection command, the level four protection command being used to control the fan to output a first-level speed and lock the fan speed, output a level four protection prompt message, and simultaneously store the state before protection; When the target distance is less than the boundary distance and the target speed is greater than the speed threshold, a Level 1 protection command is generated. The Level 1 protection command is used to cut off the main power supply of the fan motor, output a Level 1 protection prompt message, and store the pre-protection state. When the target distance is greater than the first distance and less than or equal to the second distance twice consecutively, a Level 2 protection command is generated. The Level 2 protection command is used to control the fan to output the first speed and lock the fan speed, output a Level 2 protection prompt message, and store the pre-protection state. When the target distance is greater than the second distance and less than or equal to the boundary distance twice consecutively, a Level 3 protection command is generated. The Level 3 protection command is used to control the fan to output the second speed and lock the fan speed, output a Level 3 protection prompt message, and store the pre-protection state. The controller evaluates the target distance information according to the preset level exit conditions. When the target distance information matches the preset level exit conditions, the controller controls the fan to execute the pre-protection state.

[0068] Specifically, the protection level assessment threshold includes a default protection level assessment threshold and a target protection level assessment threshold. When the target's height is less than or equal to the height threshold (e.g., 1.85m), the default protection level assessment threshold is used for protection level assessment. When the target's height is greater than the height threshold, the target protection level assessment threshold is used for protection level assessment. This achieves refined protection for the target user. When the fan controller does not access the target's physiological data via Bluetooth module, the controller uses the default protection level assessment threshold for protection level assessment.

[0069] The protection level assessment thresholds include boundary distance, first threshold, velocity threshold, first distance, and second distance. Among them, the boundary distance of the target protection level assessment threshold (e.g., 1.2m) is greater than the boundary distance of the default protection level assessment threshold (e.g., 1m); the velocity threshold of the target protection level assessment threshold (e.g., 0.2 m / s) is less than the boundary distance of the default protection level assessment threshold (e.g., 0.3 m / s).

[0070] The active protection method for unshaded fans is used to determine the protection mode of the operating unshaded fan, taking the default protection level evaluation threshold as an example.

[0071] Step 10, Level 4 protection (sensor failure) determination.

[0072] The first threshold is set to 30 seconds, and the preset number of times is 10. The trigger conditions for Level 4 protection include no valid data from the DTOF sensor for 30 consecutive seconds, and continuous abnormal DTOF data (such as sampling distance < 0 cm for 10 consecutive times).

[0073] If any condition is met, Level 4 protection is triggered, and Level 4 protection instructions are generated. If triggered: execute step 11; if not triggered: proceed to Level 1-3 protection judgment (step 12).

[0074] Step 11, Level 4 protection execution and exit.

[0075] In response to the Level 4 protection command, the controller executes the corresponding action, the motor outputs a fixed speed of 1, and the speed is locked (manual / intelligent adjustment is prohibited); the fault indication information also includes LED indication and buzzer indication, the fault LED (independent yellow light) is always on, and the buzzer has no alarm (only status indication).

[0076] The preset exit conditions include Level 4 protection exit conditions, which include the DTOF sensor recovering valid data for 10 seconds.

[0077] When the target distance information received by the controller through the DTOF sensor is valid and remains so for 10 seconds, the fourth-level protection is deactivated, the fault light goes out, the gear is unlocked, and the system returns to the working state before the fault (gear / swing angle).

[0078] Step 12, Level 1 Protection (Emergency Protection) Determination.

[0079] In some embodiments, when the target distance is less than a first distance, the current fan mode is evaluated. If the current fan mode is a non-physical button operation mode command, a level one protection command is generated. The first distance is 30cm. The first condition is met when the target approaches the fan at close range and the user is not in a non-physical button operation mode.

[0080] If the boundary distance is set to 1m and the speed threshold is 0.3 m / s, then the first condition is met when the target distance is less than 1m and the moving speed is greater than or equal to 0.3 m / s.

[0081] The controller generates a Level 1 protection command in response to the fulfillment of the first or second condition, triggering Level 1 protection and executing step 13.

[0082] If Level 1 protection is not triggered, proceed to Level 2 protection judgment (step 15).

[0083] Step 13, Level 1 protection implemented.

[0084] The controller responds instantly and performs Level 1 protection.

[0085] Immediately disconnect the main power supply to the motor, and the motor will stop rotating (without inertial delay).

[0086] The Level 1 protection alert includes a 3-second continuous buzzer (emergency alarm) and a constantly lit Level 1 protection LED (red light).

[0087] Record the fan's current operating status (including speed and oscillation angle) as "before protection".

[0088] Special handling: If the current situation is "physical button adjustment scenario" (D_eff < 30cm + button operation), the first level of protection will not be triggered for the time being, and step 35 (button adjustment logic) will be executed.

[0089] Step 14: Level 1 protection deactivated.

[0090] The preset exit conditions include Level 1 protection exit conditions, which include the target distance being greater than the boundary distance and the duration being greater than or equal to 10 seconds, i.e., D_eff≥1m (safe distance), and maintained for 10 seconds (protection exit safe time).

[0091] The steps to exit Level 1 protection include: stopping the buzzer alarm and turning off the red light; restoring the motor power and restarting in the "pre-protection state" (level 4 requires a step-by-step increase: 1→2→3→4, pausing for 1 second at each level); after exiting, return to step 7 to resume the main cycle.

[0092] Step 15, Level 2 protection (mid-range protection) determination.

[0093] The first distance is set to 30cm and the second distance to 50cm. The secondary protection trigger condition is that the target distance of two consecutive samples both satisfy 30cm<D_eff≤50cm. The controller generates a secondary protection command in response to the triggering of the secondary protection condition.

[0094] If triggered, proceed to step 16 according to the Level 2 protection instruction; if not triggered, proceed to Level 3 protection determination (step 18).

[0095] Step 16, Level 2 protection implemented.

[0096] The controller instantly responds to the secondary protection command and executes secondary protection, including: forcibly reducing the motor speed to level 1 (800 rpm) and locking the gear (prohibiting upshifting); the secondary protection prompt buzzer alarms intermittently (1 time / second, pauses after 5 seconds, repeats every 10 seconds if the object has not left); the secondary protection LED (yellow light) flashes (2 times / second); and records the "pre-protection status".

[0097] Step 17: Level 2 protection deactivated.

[0098] The preset exit conditions include the exit conditions for Level 2 protection, which include a target distance D_eff > 50cm and a duration of 10 seconds.

[0099] The steps to exit Level 2 protection include: the buzzer stops sounding and the yellow light goes out; the gear is unlocked, restoring the "pre-protection state" (gear / angle).

[0100] Return to step 7 after exiting.

[0101] Step 18, Level 3 protection (long-distance protection) determination.

[0102] The trigger condition for Level 3 protection is that the target distance in two consecutive samples both meet the condition of 50cm < D_eff ≤ 100cm, and this is confirmed by two consecutive samples; the controller generates a Level 3 protection command in response to the trigger condition of Level 3 protection.

[0103] If triggered: execute step 19 according to the Level 3 protection instruction; if not triggered: proceed to manual adjustment judgment (step 26).

[0104] Step 19, Level 3 protection implemented.

[0105] The controller instantly responds to the Level 3 protection command by forcibly reducing the motor speed to level 2 (1200 rpm) and locking the gear (only level 3 is allowed at most, limiting strong winds); the Level 3 protection LED (green light) flashes (2 times / second); and the "pre-protection status" is recorded.

[0106] Step 20: Level 3 protection deactivated.

[0107] The preset exit conditions include the Level 3 protection exit condition: D_eff > 100cm, and maintained for 10 seconds;

[0108] The exit action includes turning off the green light, unlocking the gear restriction, and restoring the "pre-protection state".

[0109] Return to step 7 after exiting.

[0110] Step 21, Protection Mode Conflict Handling.

[0111] The controller determines the protection level of the target distance information according to the preset priority, which is level 4 protection > level 1 protection > level 2 protection > level 3 protection.

[0112] Processing rule: When multiple protection conditions are met simultaneously, only the highest priority protection will be executed, and low priority protections will not be triggered.

[0113] DTOF sensors differ from traditional distance sensors such as infrared and ultrasonic sensors. Considering the appearance and portability requirements of shaded fans, DTOF sensors are only a few millimeters in size, making them easy to install and not affecting the appearance. The latter two types of sensors are large, inconvenient to package, and affect the appearance, making them unsuitable for use in shaded fan products.

[0114] Since unshaded fans are typically used in everyday scenarios, higher precision and accuracy are required. DTOF (Direct Time-of-Flight) sensors offer millimeter-level precision, are resistant to external light and temperature interference, and have a picosecond-level response time, enabling simultaneous detection of multiple moving objects. This makes them ideal for scenarios requiring high-speed, high-precision responses, and more suitable for unshaded fans compared to the other two sensor types. Infrared sensors, on the other hand, have centimeter-level accuracy and are easily affected by light and color interference, leading to false alarms. Their applicability to everyday scenarios is low, making them unsuitable for unshaded fan products. Ultrasonic sensors are susceptible to temperature and material variations, have a response time of tens of milliseconds, and multiple sensors are prone to mutual interference. In everyday scenarios, this not only increases the risk of false alarms but also protector failures, making them unsuitable for the unshaded fans described in this method.

[0115] Step 26, Physical button adjustment determination.

[0116] The controller responds to the received physical button command to determine the physical button adjustment state, that is, the trigger condition is the detection of a physical button being pressed (confirmed after debounce).

[0117] If the controller determines that the physical button adjustment state is triggered, proceed to step 27; if not triggered, proceed to Bluetooth adjustment determination (step 30).

[0118] Step 27, Key Function Analysis

[0119] Power on / off button: Short press to power on (restores the previous gear), long press for 3 seconds to power off (motor stops, all LED lights turn off).

[0120] Gear + button: Current gear +1 (4 gears cycle through to 1 gear).

[0121] Gear - key: Current gear -1 (1st gear to 4th gear cycle).

[0122] Operation feedback: Each time the button is pressed, the LED gear indicator flashes once to confirm that the operation is valid.

[0123] Step 28, button handling in protection mode.

[0124] Specifically, in some embodiments, the controller locks the button gear command in response to the first-level protection command, stores the button gear command in response to the second-level protection command, the third-level protection command, and the fourth-level protection command, and executes the stored button gear command according to the preset level exit conditions.

[0125] During Level 1 protection (shutdown), the buttons only respond to "power on / power off" and do not respond to gear adjustment. That is, the controller only performs the corresponding operation when it receives the power on / power off button command.

[0126] When the protection level is 2 / 3 / 4 (locked), the button adjustment command is temporarily stored and executed immediately after the protection is exited; that is, in the protection level 2, 3 and 4 protection, the controller stores the button gear command received by the button and adjusts the fan speed according to the stored button gear command when the protection is exited. In other words, when there is no protection mode, the button adjustment takes effect immediately and the "current working status" is updated synchronously.

[0127] Step 29: Adjust the backswing angle using the buttons.

[0128] After pressing the button, the current sway mode (seated / fitness / default) is maintained, and only the gear is updated.

[0129] In some embodiments, the controller locks the key command and outputs a key failure message when the duration of the key command exceeds a key dead time threshold.

[0130] For example, if the button freeze time threshold is set to 10 seconds, when a button is detected to be pressed continuously for more than 10 seconds, the controller will lock the button command, ignore button command input caused by the button freeze, and output a fault message. The fault message is indicated by a flashing fault light. Normal operation resumes after the button is released.

[0131] Step 30, Bluetooth adjustment determination.

[0132] The controller responds to instructions received from the Bluetooth-tagged device to determine the Bluetooth adjustment status. The received gear adjustment instructions from the Bluetooth-tagged device include power on, power off, gear position, and ±.

[0133] Execute step 31; Not triggered: Enter user status recognition (step 35).

[0134] Step 31, Bluetooth command parsing and execution.

[0135] Command verification: Verify the source of the command (only respond to the bound device) and the integrity of the command.

[0136] Execution logic: Consistent with the physical button functions (power on / power off / gear cycle).

[0137] Operation feedback: After execution, a "Adjustment successful" command is returned to the device via Bluetooth, and the LED gear indicator flashes twice.

[0138] Step 32, Bluetooth processing in protection mode.

[0139] Consistent with the rules for physical buttons, Level 1 protection only responds to power on / off commands, while other protection modes temporarily store commands and execute them upon exiting. In some embodiments, the controller receives Bluetooth commands via the Bluetooth module, locks the Bluetooth mode command in response to Level 1 protection commands, stores the Bluetooth mode command in response to Level 2, Level 3, and Level 4 protection commands, and executes the Bluetooth mode command according to preset exit conditions.

[0140] In some embodiments, when the target distance is less than a first distance and the continuous still time is greater than or equal to a second threshold, a physical button operation mode instruction is generated. The physical button operation mode instruction allows the user to control the fan to stop swinging and the motor to stop. In response to the target distance being greater than the boundary distance and the target distance increasing three times consecutively by a distance greater than or equal to the distance threshold, the motor is started and the swing angle is restored according to the button position input by the user.

[0141] Specifically, step 35 involves determining the physical button operation scenario.

[0142] The first distance is set to 30cm and the second threshold is 4s. When the target distance D_eff < 30cm (the distance is stable for 4 consecutive seconds) and no protection mode is triggered, it is determined to be a physical button operation state. The controller generates a physical button operation mode command to execute the physical button operation mode.

[0143] If the physical button operation mode is triggered, proceed to step 36; otherwise, proceed to the normal user status recognition (step 38).

[0144] Step 36, execute the button operation scenario.

[0145] The physical button operation modes include motor status, immediate stop of swing angle, motor maintaining current speed for 3 seconds (stationary waiting time), and confirmation that the user operation is complete.

[0146] The physical button operation mode exit condition is when the user is detected to be moving away (D_eff increases by ≥5cm for 3 consecutive samples) and D_eff≥100cm (safe distance).

[0147] The actions to exit the physical button operation mode include starting the motor at the gear set by the user and restoring the previous swing angle mode.

[0148] Step 37, move away from unmet trend conditions.

[0149] If the user's target is still within 30cm after 3 seconds, the motor remains stationary, and the moving away trend is detected every 3 seconds until D_eff≥100cm.

[0150] In some embodiments, when the maximum difference in target distance within a third threshold is less than or equal to a steady-state threshold, the target acceleration is calculated. If the target acceleration is less than the sedentary acceleration, the swivel motor is controlled to execute a sedentary mode. If the target acceleration is greater than the fitness acceleration, the swivel motor is locked to execute a fitness mode; otherwise, a full swivel mode is executed. In another embodiment, the controller receives the target acceleration via a Bluetooth module. If the maximum difference in target distance within a third threshold is less than or equal to a steady-state threshold, and the target acceleration is less than the sedentary acceleration, the swivel motor is controlled to execute a sedentary mode. If the target acceleration is greater than the fitness acceleration, the swivel motor is locked to execute a fitness mode; otherwise, a full swivel mode is executed.

[0151] Specifically, step 38, regular user status recognition (non-button scenario).

[0152] The stability of the target distance is determined based on the target distance. The third threshold is set to 4s. If the target distance D_eff fluctuates by ≤±2cm within 4 consecutive seconds, it is determined that the distance is "stable"; otherwise, it is "unstable" (step 40).

[0153] Step 39: Acceleration state determination.

[0154] If the target acceleration data within 4 consecutive seconds is judged and the target acceleration A_user≤0.1g, it is judged as "acceleration stationary". At this time, the target is "sitting and working", and the sitting mode is executed by starting the swing angle motor and swinging back and forth within ±15° of the center.

[0155] When the target acceleration A_user > 0.3g, it is determined to be "acceleration exercise". At this time, the target is "indoor fitness" and the fitness mode is to lock the user's area with the oscillating motor and deliver air to a fixed point.

[0156] If the target acceleration is between the two values, it is determined that "acceleration is uncertain" and proceeds to step 40.

[0157] Step 40: No clear user status.

[0158] If the target distance is unstable or the target acceleration is uncertain, the oscillating motor will execute the default full oscillating mode, which is to reciprocate the airflow at a full oscillating angle of ±60°.

[0159] In some embodiments, the controller receives temperature and humidity information by connecting to a temperature sensor and a humidity sensor, receives physiological data via a Bluetooth module, and generates environmental mode instructions based on the temperature, humidity, and physiological data. The environmental mode instructions include a comfortable environmental mode instruction, an overheated environmental mode instruction, and an overcooled environmental mode instruction. The comfortable environmental mode instruction is used to maintain the current fan speed and oscillation angle, the overheated environmental mode instruction is used to increase the speed by one level, and the overcooled environmental mode instruction is used to decrease the speed by one level.

[0160] Specifically, the controller adjusts the fan settings according to the user's condition and the current environment based on data from various sensors.

[0161] Step 41, Determine the comfortable environment.

[0162] The controller performs a mode check based on the temperature information T_env, humidity information H_env, and physiological data T_user and HR_user received within 5 consecutive seconds. If the following conditions are met: 22℃≤T_env≤26℃; 40%≤H_env≤60%; 36.0℃≤T_user≤37.2℃; 60≤HR_user≤90 times / minute, the check is set to a comfortable environment mode. In another embodiment, if no physiological data is available, the controller determines the environment mode based on the temperature and humidity information.

[0163] The Comfort Mode command maintains the current gear and current steering angle mode (step 46).

[0164] Step 42, Determine the overheated environment.

[0165] If any of the following sensor data conditions are met for more than 3 seconds: T_env > 26℃; H_env > 60%; T_user > 37.2℃ (ignore if no physiological data is available); HR_user > 90 times / min (ignore if no physiological data is available), then the system is determined to enter overheating environment mode. Proceed to step 43.

[0166] Step 43, overheat setting adjustment.

[0167] The overheating environment mode command controls the current gear +1 (up to gear 4). In fitness mode, it responds to the overheating environment mode command by increasing the gear by two levels, and locks the gear when the protection level is level 2 or level 4, and sets the highest gear to level 3 RPM when the protection level is level 3.

[0168] Regarding protection mode restrictions, the maximum upgrade level is 3 in the Level 3 protection mode (Level 2); the upgrade level is prohibited in the Level 2 and Level 4 protection modes (Level 1) (priority safety / fault protection).

[0169] If the fitness scene is also identified as "indoor fitness", the level will be increased by 1 level (up to 4 levels).

[0170] Step 44, Determine if the environment is too cold (supplementary logic).

[0171] If the sensor data T_env < 22℃ and T_user < 36.0℃ (only T_env is considered when there is no physiological data) lasts for 3 seconds, the controller determines that it is in supercooled environment mode and generates a supercooled environment mode command.

[0172] In response to the overcooled environment mode command, the current gear is reduced by 1 (lowest gear 1), and the sway mode is maintained.

[0173] Step 45, Status Update and Storage.

[0174] After intelligent adjustment, the "current working status" (gear / slewing angle) is updated and stored in EEPROM (not lost when power is off).

[0175] Step 46, return to the main loop.

[0176] After completing all judgments and executions, return to step 7 and repeat the "data acquisition → logic judgment → action execution" process.

[0177] In some similar embodiments, the controller performs motor fault inventory based on the motor speed. When the motor speed deviates from the set gear by more than 200 rpm (after 5 consecutive samplings), or when the motor drive module feeds back an overcurrent or overtemperature signal, the motor power supply is immediately cut off, the fault light (red + yellow + green flashing alternately) and the buzzer sounds continuously; manual power-off and restart are required to restore the motor.

[0178] If the protection mode or manual adjustment is triggered in the loop, the current process will be interrupted immediately, and the process will jump to the corresponding module.

[0179] The various embodiments of this disclosure have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or technical improvements to the embodiments in the market, or to enable others skilled in the art to understand this document.

Claims

1. A method of active protection of a fan without a cover, characterized in that, The application relates to a fan safety protection method and device. The DTOF sensor is fixed on the body of the fan, and real-time target distance information is collected by the DTOF sensor, and the target speed is calculated when the target distance is less than or equal to the boundary distance; The controller of the fan receives the target distance information and the target speed through the DTOF sensor and carries out protection level evaluation, including: When the real-time target distance information interruption duration is greater than a first threshold value, or the number of times that the target distance is less than zero is greater than or equal to a preset number of times, the sensor is judged to be faulty, and a fourth protection instruction is generated, the fourth protection instruction is used for controlling the fan to output a first speed and lock the fan gear, outputting a fourth protection prompt information, and storing the state before protection at the same time; When the target distance is less than the boundary distance and the target speed is greater than a speed threshold value, a first protection instruction is generated, the first protection instruction is used for cutting off the main power supply of the fan motor, outputting a first protection prompt information, and storing the state before protection; When the target distance is greater than a first distance and less than or equal to a second distance for two times, a second protection instruction is generated, the second protection instruction is used for controlling the fan to output a first speed and lock the fan gear, outputting a second protection prompt information, and storing the state before protection; When the target distance is greater than the second distance and less than or equal to the boundary distance for two times, a third protection instruction is generated, the third protection instruction is used for controlling the fan to output a second speed and lock the fan gear, outputting a third protection prompt information, and storing the state before protection; The controller evaluates the target distance information according to a preset level exit condition, and controls the fan to execute the state before protection when the target distance information matches the preset level exit condition.

2. The method of claim 1, wherein, The controller locks the key gear instruction in response to the first protection instruction, stores the key gear instruction in response to the second protection instruction, the third protection instruction and the fourth protection instruction, and executes the stored key gear instruction according to the preset level exit condition.

3. The method of claim 2, wherein, The controller locks the key instruction when the duration of the key instruction is greater than a key jamming time threshold value, and outputs a key fault prompt information.

4. The method of claim 3, wherein, When the target distance is less than the first distance and the continuous stationary time is greater than or equal to a second threshold value, a physical key operation mode instruction is generated, the physical key operation mode instruction is used for controlling the fan to stop the swing angle and the motor to be stationary, and in response to the target distance being greater than the boundary distance and the target distance increasing distance being greater than or equal to an away threshold value for three times, the motor is started and the swing angle is restored according to the key gear input by the user.

5. The method of claim 4, wherein, When the target distance is less than the first distance, the current mode of the fan is evaluated, and the first protection instruction is generated when the current mode of the fan is a non-physical key operation mode instruction.

6. The method of claim 1, wherein, The controller receives a Bluetooth instruction through a Bluetooth module, and locks the Bluetooth gear instruction in response to the first protection instruction, stores the Bluetooth gear instruction in response to the second protection instruction, the third protection instruction and the fourth protection instruction, and executes the Bluetooth gear instruction according to the preset level exit condition.

7. The method of claim 1, wherein, When the maximum difference of the target distance within a third threshold value is less than or equal to a stable state threshold value, the target acceleration is calculated, and the swing motor is controlled to execute a sitting mode when the target acceleration is less than a sitting acceleration, the swing motor is locked to execute a fitness mode when the target acceleration is greater than a fitness acceleration, otherwise, a full swing mode is executed.

8. The method of claim 7, wherein, The controller receives temperature information and humidity information through the connection of the temperature sensor and the humidity sensor, receives physiological data through the Bluetooth module, and generates an environment mode instruction according to the temperature information, the humidity information and the physiological data, the environment mode instruction including a comfortable environment mode instruction, an overheated environment mode instruction and an overcooled environment mode instruction, the comfortable environment mode instruction being used for maintaining the current gear and swing angle of the fan, the overheated environment mode instruction being used for increasing one gear, and the overcooled environment mode instruction being used for decreasing one gear, two gears being increased in response to the overheated environment mode instruction in the fitness mode, and the gear being locked when the protection level is the second protection and the fourth protection, and the highest gear being set as the third rotation speed when the protection level is the third protection.

9. The method of claim 1, wherein, The step of the controller of the fan receiving target distance information and target speed through the DTOF sensor and performing protection level evaluation according to the protection level evaluation threshold value further includes: the controller of the fan receiving target physiological data through the Bluetooth module, the target physiological data including target height, and determining the protection level evaluation threshold value according to the target height; and the controller of the fan receiving target distance information and target speed through the DTOF sensor and performing protection level evaluation according to the protection level evaluation threshold value.

10. A hooded fan characterized by, The fan includes a controller, a DTOF sensor, a temperature sensor, a humidity sensor and a Bluetooth module, the controller receiving target distance information through the DTOF sensor, receiving environment temperature through the temperature sensor, receiving environment humidity through the humidity sensor, and receiving user physiological data through the Bluetooth module, and the controller performing the active protection method of the fan without a cover according to the received target distance information, environment temperature, environment humidity and user physiological data, the DTOF sensor being arranged behind the blade when the blade is transparent, and the DTOF sensor being arranged in front of the blade when the blade is opaque.

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