Fire door linkage intelligent control method based on multi-sensor fusion

Abstract

The present application relates to the technical field of fire door control, in particular to a multi-sensor fusion fire door linkage intelligent control method, a plurality of sensors are installed in an underground garage to collect state data of the environment and fire door body in real time, the collected data is divided into an early warning stage, an early confirmation stage, a medium spreading stage and a late isolation stage according to fire conditions, when the collected data is identified as the early warning stage, the door body multi-dimensional sensor is switched to a high-frequency sampling mode, and the pre-tightening force of the door closer of the fire door around the fire source is adjusted, the timing of "smoke evacuation prior to door closing" is adopted in the early stage, the "allowed passing direction" is dynamically adjusted according to the real-time smoke concentration and personnel distribution in the medium stage, the vehicle and pedestrian are hard isolated by controlling the opening angle (full opening / half opening / micro opening) of the fire door, the mixed traffic congestion is prevented, and the risk of trampling is reduced.

Description

Technical Field

[0001] This invention relates to the field of fire door control technology, and more specifically, to a multi-sensor fusion-based intelligent control method for fire door linkage. Background Technology

[0002] Fire doors, as critical facilities for isolating smoke and fire during a fire, have their linkage control methods directly impacting evacuation efficiency and the safety of life and property. Existing fire door control systems primarily rely on zone signals from fire alarm controllers, implementing a single strategy of immediately closing all relevant fire doors upon fire confirmation. However, in actual fire scenarios, this rigid control method suffers from the following technical shortcomings:

[0003] Traditional methods lack precise identification and response to the various stages of a fire's evolution. From smoldering and initial open flames to smoke spread and full-blown combustion, evacuation needs and fire door control strategies should differ at each stage. Existing systems often close fire doors prematurely before personnel have evacuated, causing blockages in evacuation routes; or they leave doors open even when the fire is out of control, leading to rapid smoke diffusion. In densely populated areas (such as underground parking garages and hospitals), normally closed fire doors are frequently forced open or obstructed, while normally open fire doors are difficult to close reliably during a fire. More critically, existing systems cannot adjust doors to fully open, half-open, or slightly open angles to accommodate the mixed traffic of vehicles and pedestrians, leading to congestion and increased risk of stampedes.

[0004] Therefore, there is an urgent need for a fire door linkage intelligent control method based on multi-sensor fusion, which can adaptively adjust the passage direction and opening angle of the fire door according to the stage of fire evolution, and make dynamic adjustments based on the fire situation to improve the safety and efficiency of personnel evacuation during a fire. Summary of the Invention

[0005] The purpose of this invention is to provide a multi-sensor fusion-based intelligent control method for fire door linkage, to improve upon the problems of existing systems that often close fire doors prematurely before personnel have evacuated, causing obstruction of evacuation routes; or keep doors open even when the fire is out of control, leading to rapid smoke diffusion. In densely populated areas (such as underground parking garages and hospitals), normally closed fire doors are frequently forcibly opened or obstructed by people, while normally open fire doors are difficult to close reliably during a fire. More importantly, existing systems cannot adjust the doors to different angles such as fully open, half open, or slightly open according to the mixed traffic needs of vehicles and pedestrians, leading to congestion and increased risk of trampling.

[0006] To achieve the above objectives, the embodiments of this application provide the following technical solutions:

[0007] This application provides a multi-sensor fusion-based intelligent control method for fire door linkage, applied to an underground parking garage. The control method includes: installing multiple sensors in the underground parking garage to collect real-time environmental and fire door status data; dividing the collected data into early warning, early confirmation, mid-stage spread, and late-stage isolation phases based on the fire situation; the multiple sensors include an air quality sensor, a multispectral flame detector, a smoke concentration sensor, a carbon monoxide sensor, a thermal imaging camera, a visible light camera, a millimeter-wave radar, a geomagnetic sensor, and a multi-dimensional sensor for the door; when the collected data identifies the early warning phase, switching the multi-dimensional sensor for the door to a high-frequency sampling mode and adjusting the pre-tightening force of the door closers around the fire source; when the collected data identifies the early confirmation phase, first activating the smoke exhaust fan in the fire compartment where the fire source is located, and monitoring the negative pressure at the smoke exhaust vents in real time. After the negative pressure stabilizes, the fire doors are closed, closing the fire doors in the corresponding zones and adjusting the fire doors in adjacent zones to a semi-locked state. When the collected data identifies the intermediate spread stage, a real-time thermal map and movement direction of personnel are constructed based on millimeter-wave radar and thermal imaging cameras. Combined with the smoke concentration inside each fire door, the passage direction and opening angle of each fire door are dynamically adjusted. Based on the identification of geomagnetic sensors and visible light cameras, for passages shared by vehicles and pedestrians, some fire doors are fully opened for vehicle passage, and the fire doors on adjacent pedestrian passages are adjusted to a semi-open mode. When the collected data identifies the late isolation stage, the fire doors are closed one by one in order of distance from the fire source, with a preset time interval between each closure. After each fire door is closed, the sealing strip pressure is detected by a multi-dimensional sensor on the door. If the pressure is lower than a preset threshold, a secondary closing action is triggered.

[0008] Optionally, the criteria for classifying the collected data into early warning stage, early confirmation stage, mid-stage spread stage, and late isolation stage based on the fire situation are as follows:

[0009] Obtain the highest temperature of battery cells in the charging station area. and the rate of temperature rise of battery cells ,when This was determined to be an early sign of thermal runaway; the concentration of total volatile organic compounds (VOCs) measured by the air quality sensor was obtained. ,when If the emission persists for more than 3 seconds, it is determined that the battery is releasing combustible gas; the smoke concentration is then obtained from the smoke concentration sensor. ,when However, if the early confirmation threshold has not yet been reached, it is determined to be the initial stage of smoldering; when any of the above determination conditions are met, the confirmation timer is started. If the condition disappears within 5 seconds, the warning stage is exited; if it continues for 5 seconds, it is determined to be the early warning stage.

[0010] Acquire ultraviolet flame detection signals measured by a multispectral flame detector and infrared flame detection signal Open flame Confirmed, when A smoke concentration ≥0.7 is considered a confirmed open flame; this is based on the smoke concentration measured by the smoke concentration sensor. And the carbon monoxide concentration measured by the carbon monoxide sensor Double verification is performed to determine whether the gas is hazardous, based on the combined value of smoke and CO. When the concentration is ≥1.0, it is considered a flue gas hazard; if 0.7 or If the condition persists for more than 2 seconds, it is considered to be in the early confirmation stage.

[0011] ;

[0012] ;

[0013] in, , The dangerous threshold for smoke concentration. The CO hazard threshold, ;

[0014] Obtain the carbon monoxide concentration values ​​measured by carbon monoxide sensors in adjacent fire compartments to obtain the CO concentration difference between adjacent fire compartments. Based on the CO concentration difference between adjacent fire compartments CO concentration in adjacent fire compartments To determine whether flue gas has spread across zones, when and The system determines that smoke has significantly intruded into adjacent zones; it pre-marks the boundaries of fire compartments and calculates the highest and lowest temperature differences within 1 meter on both sides of the boundary; a temperature difference ≥15℃ indicates that the fire has approached or crossed the boundary; and it uses thermal imaging to determine the highest temperature within the fire source zone. and the rate of temperature rise obtained by differentiating the temperature values ​​of the time series. To determine whether the temperature rise in the fire source zone is out of control, when and If the temperature rise in the fire source zone is out of control, it is determined to be in the intermediate spread stage; if any of the above conditions are met, it is determined to be in the intermediate spread stage.

[0015] The fire zone and adjacent evacuation routes were confirmed to be free of any moving targets and stationary personnel through both thermal imaging cameras and millimeter-wave radar, confirming the evacuation of personnel. Vehicle identification was performed using geomagnetic sensors and visible light cameras to confirm the evacuation of vehicles. Once it is confirmed that the fire is no longer spreading rapidly, the final fire doors are closed in sequence. When all personnel and vehicles have been evacuated and the fire is no longer spreading rapidly, it is considered to be in the late isolation stage. If new personnel are detected entering during the fire door closure process, the process is immediately terminated and the process is reverted to the mid-spread stage.

[0016] Optionally, adjusting the pre-tightening force of the door closers around the fire source specifically includes:

[0017] Based on the location of the fire source, the fire source sensor installation point is used as the center, and all fire doors within a radius of 10m are used to divide the fire source area. If the fire source is located inside the fire compartment, all doors in that compartment and the doors of adjacent compartments that directly face the fire source need to have their door closers preload adjusted. The door closer is a stepper motor driven door closer, and a door closer spring is installed inside the door closer. The preload of the door closer spring is linearly adjusted by a control signal.

[0018] Optionally, when the collected data is identified as the early confirmation stage, the smoke exhaust fan of the fire compartment where the fire source is located is first started, the negative pressure of the smoke exhaust outlet is monitored in real time, and after the negative pressure stabilizes, the fire door closing operation is performed to close the fire door of the corresponding compartment and adjust the fire door of the adjacent compartment to a semi-locked state, specifically including:

[0019] The fire compartment where the fire source is located is determined. Based on the fire source compartment identification, the smoke exhaust fans of that compartment and adjacent compartments are automatically started. A differential pressure sensor is installed at the smoke exhaust outlet of the smoke exhaust fan. After the smoke exhaust fan start command is issued, the data of the differential pressure sensor is monitored in real time, and the negative pressure value of the smoke exhaust outlet is defined. During normal smoke exhaust, the negative pressure value changes with the fan speed and pipe resistance.

[0020] Continuously collect the negative pressure at the smoke exhaust outlet, calculate the fluctuation rate and rise rate within the sliding window. When the fluctuation rate is ≤0.1 and the rise rate is ≤5Pa / s, and the duration is ≥2s, record the negative pressure value at this time, and perform the fire door closing operation.

[0021] Based on the identified fire compartment, a closing command is sent to all fire doors within that compartment. During the closing process, graded torque control is used. The first 0.5 seconds are started with 50% of the rated torque to avoid impact. When the door angle θ≤5°, the torque is switched to 100% to ensure a seal. After closing, the door magnetic sensor verifies whether the latch is in place. If it is not in place, a local audible and visual alarm is triggered, and the door is closed again. The fire doors in the fire compartment adjacent to the fire compartment are adjusted to a semi-locked state. During the closing of the fire doors in the compartment, the negative pressure value of the smoke exhaust outlet is continuously monitored. If the negative pressure of the smoke exhaust outlet drops by more than 30Pa due to the closing of the door, the frequency of the smoke exhaust fan is automatically increased or the valve is opened to maintain the negative pressure value of the smoke exhaust outlet ≥ (0.8 * fluctuation rate) to ensure that the closing action does not significantly reduce the smoke exhaust efficiency. If the negative pressure cannot reach 20Pa within 10 seconds after the smoke exhaust fan starts, it is judged as a smoke exhaust system malfunction. At this time, the door closing operation is forcibly executed, and a "smoke exhaust failure" alarm is reported, prompting personnel to use other passages for evacuation.

[0022] Optionally, when the collected data is identified as being in the mid-stage of the spread, a real-time thermal map and movement direction of personnel are constructed based on millimeter-wave radar and thermal imaging cameras. Combined with the smoke concentration inside each fire door, the passage direction and opening angle of each fire door are dynamically adjusted. Based on the identification data from geomagnetic sensors and visible light cameras, for passages shared by vehicles and pedestrians, some fire doors are fully opened for vehicle passage, and fire doors on adjacent pedestrian passages are adjusted to a half-open mode. Specifically, this includes:

[0023] Based on thermal imaging cameras, millimeter-wave radar, multispectral flame detectors, multidimensional door sensors, and carbon monoxide sensors, the carbon monoxide concentration on the fire zone and the safety zone is collected in real time. Temperature on the fire side Flame confirmation signal Density of people in front of the gate Actual opening angle of the door And the direction and speed of movement of people or vehicles, and determine an independent passage direction state for each fire door according to preset conditions;

[0024] when If the condition is met for a duration of ≥3 seconds, it is determined to be a two-way passage state;

[0025] when If any of the conditions in the fire door are met and the condition lasts for ≥2 seconds, the fire door is determined to be in a one-way passage state, and the dangerous side and the safe side are determined by comparing the carbon monoxide concentrations on both sides of the fire door.

[0026] when If no personnel or vehicles approach within 2 meters in front of the fire door for 10 consecutive seconds, or if the door's multi-dimensional sensor detects a serious mechanical failure, it is determined to be in a fully locked state.

[0027] The target opening angle is calculated every 0.2 seconds based on a preset priority. Among them, the full-open mode is Half-open mode is The door closer applies a holding torque of 30-50N, and adjusts the torque according to the width of the object being passed. and movement speed Dynamically adjusted; based on the actual angle feedback from the magnetic encoder. A PID controller is used to drive the door closer motor, so that... track The response time is less than 0.5 seconds.

[0028] The beneficial effects of this invention are as follows:

[0029] This invention, based on multi-sensor fusion and adaptive division of fire stages, achieves refined linkage control of fire doors from early warning to late-stage isolation: in the early stage, the "smoke exhaust takes priority over door closing" sequence is adopted; in the middle stage, the fire doors dynamically adjust the "permitted passage direction" according to the real-time smoke concentration and personnel distribution; and by controlling the opening angle of the fire doors (fully open / half open / slightly open), hard isolation between vehicles and pedestrians is achieved, preventing mixed traffic congestion and reducing the risk of trampling.

[0030] This invention integrates multi-sensor data in real time, achieving a fully closed-loop intelligent linkage from fire detection to fire door control. It proactively warns of potential hazards such as aging door closers at the very early stages, preventing door failure during a fire from the outset. Furthermore, innovative designs such as the coordinated timing of smoke exhaust fans and fire doors, sequential door closing and sealing pressure verification, and vehicle and pedestrian separation overcome the fragmented operation of existing subsystems, significantly improving the system's effectiveness in real fire environments.

[0031] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing embodiments of the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description and the accompanying drawings. Attached Figure Description

[0032] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 This is a schematic flowchart of the multi-sensor fusion intelligent control method for fire door linkage described in this embodiment of the invention. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0035] It should be noted that similar reference numerals or letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, in the description of this invention, terms such as "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0036] like Figure 1 As shown, this embodiment provides a multi-sensor fusion intelligent control method for fire door linkage, which is applied to an underground garage. The control method includes steps S1, S2, S3, S4 and S5.

[0037] Step S1: Install multiple sensors in the underground garage to collect real-time status data of the environment and fire doors. Divide the collected data into early warning stage, early confirmation stage, mid-term spread stage and late isolation stage according to the fire situation. The multiple sensors include air quality sensor, multispectral flame detector, smoke concentration sensor, carbon monoxide sensor, thermal imaging camera, visible light camera, millimeter wave radar, geomagnetic sensor and door multidimensional sensor.

[0038] Step S2: When the collected data is identified as an early warning stage, the multi-dimensional sensor of the door is switched to high-frequency sampling mode, and the pre-tightening force of the door closer of the fire door around the fire source is adjusted.

[0039] Step S3: When the collected data is identified as the early confirmation stage, first start the smoke exhaust fan of the fire compartment where the fire source is located, monitor the negative pressure of the smoke exhaust outlet in real time, and after the negative pressure stabilizes, perform the fire door closing operation, close the fire door of the corresponding compartment, and adjust the fire door of the adjacent compartment to a semi-locked state.

[0040] Step S4: When the collected data is identified as the mid-stage of the spread, a real-time thermal map and movement direction of personnel are constructed based on millimeter-wave radar and thermal imaging cameras. Combined with the smoke concentration inside each fire door, the passage direction and opening angle of each fire door are dynamically adjusted. Based on the identification of geomagnetic sensors and visible light cameras, for passages shared by vehicles and pedestrians, some fire doors are fully opened to allow vehicles to pass, and the fire doors on adjacent pedestrian passages are adjusted to a half-open mode.

[0041] Step S5: When the collected data is identified as the late isolation stage, the fire doors are closed one by one in order of distance from the fire source. The closing interval for each door is preset. After each fire door is closed, the sealing strip pressure is detected by the door body multi-dimensional sensor. If the pressure is lower than the preset threshold, a secondary closing action is triggered.

[0042] This invention, based on multi-sensor fusion and adaptive division of fire stages, achieves refined linkage control of fire doors from early warning to late-stage isolation: in the early stage, the "smoke exhaust takes priority over door closing" sequence is adopted; in the middle stage, the fire doors dynamically adjust the "permitted passage direction" according to the real-time smoke concentration and personnel distribution; and by controlling the opening angle of the fire doors (fully open / half open / slightly open), hard isolation between vehicles and pedestrians is achieved, preventing mixed traffic congestion and reducing the risk of trampling.

[0043] This invention integrates multi-sensor data in real time, achieving a fully closed-loop intelligent linkage from fire detection to fire door control. It proactively warns of potential hazards such as aging door closers at the very early stages, preventing door failure during a fire from the outset. Furthermore, innovative designs such as the coordinated timing of smoke exhaust fans and fire doors, sequential door closing and sealing pressure verification, and vehicle and pedestrian separation overcome the fragmented operation of existing subsystems, significantly improving the system's effectiveness in real fire environments.

[0044] In this embodiment, the criteria for classifying the collected data into early warning stage, early confirmation stage, mid-stage spread stage, and late isolation stage according to the fire situation in step S1 are as follows:

[0045] Obtain the highest temperature of battery cells in the charging station area. and the rate of temperature rise of battery cells ,when This was determined to be an early sign of thermal runaway; the concentration of total volatile organic compounds (VOCs) measured by the air quality sensor was obtained. ,when If the emission persists for more than 3 seconds, it is determined that the battery is releasing combustible gas; the smoke concentration is then obtained from the smoke concentration sensor. ,when However, if the early confirmation threshold has not yet been reached, it is determined to be the initial stage of smoldering; when any of the above determination conditions are met, the confirmation timer is started. If the condition disappears within 5 seconds, the warning stage is exited; if it continues for 5 seconds, it is determined to be the early warning stage.

[0046] Acquire ultraviolet flame detection signals measured by a multispectral flame detector and infrared flame detection signal Open flame Confirmed, when A smoke concentration ≥0.7 is considered a confirmed open flame; this is based on the smoke concentration measured by the smoke concentration sensor. And the carbon monoxide concentration measured by the carbon monoxide sensor Double verification is performed to determine whether the gas is hazardous, based on the combined value of smoke and CO. When the concentration is ≥1.0, it is considered a flue gas hazard; if 0.7 or If the condition persists for more than 2 seconds, it is considered to be in the early confirmation stage.

[0047] ;

[0048] ;

[0049] in, , The dangerous threshold for smoke concentration. The CO hazard threshold, ;

[0050] Obtain the carbon monoxide concentration values ​​measured by carbon monoxide sensors in adjacent fire compartments to obtain the CO concentration difference between adjacent fire compartments. Based on the CO concentration difference between adjacent fire compartments CO concentration in adjacent fire compartments To determine whether flue gas has spread across zones, when and The system determines that smoke has significantly intruded into adjacent zones; it pre-marks the boundaries of fire compartments and calculates the highest and lowest temperature differences within 1 meter on both sides of the boundary; a temperature difference ≥15℃ indicates that the fire has approached or crossed the boundary; and it uses thermal imaging to determine the highest temperature within the fire source zone. and the rate of temperature rise obtained by differentiating the temperature values ​​of the time series. To determine whether the temperature rise in the fire source zone is out of control, when and If the temperature rise in the fire source zone is out of control, it is determined to be in the intermediate spread stage; if any of the above conditions are met, it is determined to be in the intermediate spread stage.

[0051] The fire zone and adjacent evacuation routes were confirmed to be free of any moving targets and stationary personnel through both thermal imaging cameras and millimeter-wave radar, confirming the evacuation of personnel. Vehicle identification was performed using geomagnetic sensors and visible light cameras to confirm the evacuation of vehicles. or Once it is confirmed that the fire is no longer spreading rapidly, the final fire doors are closed in sequence. When all personnel and vehicles have been evacuated and the fire is no longer spreading rapidly, it is considered to be in the late isolation stage. If new personnel are detected entering during the fire door closure process, the process is immediately terminated and the process is reverted to the mid-spread stage.

[0052] To avoid false jumps in stages caused by transient noise from the sensors, the system introduces an integral counter for each stage upgrade condition: The degree to which the trigger condition for the kth stage is satisfied (0 or 1).

[0053] System maintenance points:

[0054] ;

[0055] when At that time, we officially enter the kth stage.

[0056] Typical parameters: (Late stages require a longer period of stable observation).

[0057] In this embodiment, the step S2 of adjusting the pre-tightening force of the door closers of the fire doors around the fire source specifically includes:

[0058] Based on the location of the fire source, the fire source perimeter is divided within a 10m radius of all fire doors centered on the fire source sensor installation point. If the fire source is located within a fire compartment, all doors in that compartment and doors in adjacent compartments directly facing the fire source require adjustment of the door closer's preload force. The door closer is a stepper motor driven door closer with a closing spring inside. The preload force of the closing spring is linearly adjusted via a control signal, sending a preload command to the door closer driver to set the target preload force. :

[0059] ;

[0060] This indicates the minimum preload force required for the door to close normally on a daily basis (determined by door weight, wind pressure, etc.), with a typical value of 50~80N; This represents the additional preload, with a value of [value missing]. ,in: This is the preloading factor, with a default value of 0.3 (which increases the maximum capacity by 30%). This represents the current fatigue coefficient of the door, ranging from 0 to 1. The higher the fatigue level, the smaller the preload, to prevent overload damage. The maximum preload force that the door closer can provide (e.g., 150N).

[0061] Upon triggering an early warning, preloading is executed immediately, with a response time of <100ms; if the early warning is triggered within... If the alert is not upgraded to early confirmation within 60 seconds and all warning conditions disappear, release the preload and restore. If upgraded to early confirmation, the preload state is maintained, and the increased preload force is used directly in subsequent closing commands to quickly close the door.

[0062] The door's multi-dimensional sensors include a magnetic encoder, strain gauges, accelerometers, and Hall current sensors. The magnetic encoder is used to measure the door opening angle θ; the strain gauges are used to measure the door closer spring stress σ; the accelerometers are used to measure the door's angular acceleration α; and the Hall current sensors are used to measure the door closer motor current I. High-frequency sampling continues throughout the early warning stage and all subsequent stages, until a fire occurs.

[0063] sensor Measurement parameters Normal sampling rate Very early warning sampling rate Magnetic encoder Door opening angle θ 1 Hz 10 Hz strain gauge Door closer spring stress σ 0.5 Hz 10 Hz accelerometer Door angular acceleration α 1 Hz 20 Hz Hall current sensor Door closer motor current I 1 Hz 20 Hz

[0064] Transient noise is removed by using a sliding window mid-range filter (window length L=5), and then stored in a circular buffer (capacity N=1000, corresponding to 100 seconds of data).

[0065] Maintain the following health characteristics for each fire door:

[0066] Static baseline: After the system installation and debugging are completed, perform 3 normal door opening and closing tests and record the results:

[0067] Normal closing time (Time from fully open to fully closed, typically 3-5 seconds); Normal closing angular velocity curve Normal door closer motor current curve Door closer spring stiffness .

[0068] In high-frequency sampling mode, record five consecutive normal door opening and closing cycles (if no one opens the door during the early warning period, record the static stress value under the current state). Calculate the fatigue coefficient. :

[0069] ;

[0070] in, This represents the spring stress when the door closer is fully compressed. The stress is the stress at the time of manufacture or the most recent replacement; η close to 0 indicates healthy, and close to 1 indicates severe fatigue.

[0071] Friction coefficient increment Δμ: estimated by the angular acceleration decay rate during the door closing process.

[0072] ;

[0073] If η≥0.7 or Δμ≥0.5, the system immediately generates a "Fire Door Mechanical Failure" work order, indicating that the door closer needs to be replaced or the hinges need to be lubricated. This warning can trigger maintenance before a fire occurs, preventing the door from failing during a fire.

[0074] In this embodiment, when the collected data in step S3 is identified as the early confirmation stage, the smoke exhaust fan of the fire compartment where the fire source is located is first started, the negative pressure of the smoke exhaust outlet is monitored in real time, and after the negative pressure stabilizes, the fire door closing operation is performed to close the fire door of the corresponding compartment and adjust the fire door of the adjacent compartment to a semi-locked state, specifically including:

[0075] The fire compartment where the fire source is located is determined. Based on the fire source compartment identification, the smoke exhaust fans of that compartment and adjacent compartments are automatically started. A differential pressure sensor is installed at the smoke exhaust outlet of the smoke exhaust fan. After the smoke exhaust fan start command is issued, the data of the differential pressure sensor is monitored in real time, and the negative pressure value of the smoke exhaust outlet is defined. During normal smoke exhaust, the negative pressure value changes with the fan speed and pipe resistance.

[0076] Continuously collect the negative pressure at the smoke exhaust outlet, calculate the fluctuation rate and rise rate within the sliding window. When the fluctuation rate is ≤0.1 and the rise rate is ≤5Pa / s, and the duration is ≥2s, record the negative pressure value at this time, and perform the fire door closing operation.

[0077] The specific calculations for volatility and rate of rise within the sliding window are as follows:

[0078] (Window length Δt = 3s)

[0079] ;

[0080] The volatility within the sliding window; The negative pressure value at the smoke exhaust outlet is continuously collected by the system. The rate of increase.

[0081] Based on the identified fire compartment, a closing command is sent to all fire doors within that compartment. During the closing process, graded torque control is used. The first 0.5 seconds are started with 50% of the rated torque to avoid impact. When the door angle θ≤5°, the torque is switched to 100% to ensure a seal. After closing, the door magnetic sensor verifies whether the latch is in place. If it is not in place, a local audible and visual alarm is triggered, and the door is closed again. The fire doors in the fire compartment adjacent to the fire compartment are adjusted to a semi-locked state. During the closing of the fire doors in the compartment, the negative pressure value of the smoke exhaust outlet is continuously monitored. If the negative pressure of the smoke exhaust outlet drops by more than 30Pa due to the closing of the door, the frequency of the smoke exhaust fan is automatically increased or the valve is opened to maintain the negative pressure value of the smoke exhaust outlet ≥ (0.8 * fluctuation rate) to ensure that the closing action does not significantly reduce the smoke exhaust efficiency. If the negative pressure cannot reach 20Pa within 10 seconds after the smoke exhaust fan starts, it is judged as a smoke exhaust system malfunction. At this time, the door closing operation is forcibly executed, and a "smoke exhaust failure" alarm is reported, prompting personnel to use other passages for evacuation.

[0082] During smoke extraction and door closing, the semi-locked fire doors in adjacent zones remain open with a gentle push. The system uses door magnetic sensors to detect whether these doors are being opened frequently (e.g., more than 6 times per minute). If the threshold is exceeded, it is determined that there is a large number of people evacuating, and the door is automatically kept open for 10 seconds (normally 3 seconds) to avoid injury to evacuees due to frequent rebound.

[0083] In this embodiment, in step S4, when the collected data is identified as being in the mid-stage of the spread, a real-time thermal map and movement direction of personnel are constructed based on millimeter-wave radar and thermal imaging cameras. Combined with the smoke concentration inside each fire door, the passage direction and opening angle of each fire door are dynamically adjusted. Based on the identification data from geomagnetic sensors and visible light cameras, for passages shared by vehicles and pedestrians, some fire doors are fully opened for vehicle passage, and fire doors on adjacent pedestrian passages are adjusted to a half-open mode. Specifically, this includes:

[0084] Based on thermal imaging cameras, millimeter-wave radar, multispectral flame detectors, multidimensional door sensors, and carbon monoxide sensors, the carbon monoxide concentration on the fire zone and the safety zone is collected in real time. Temperature on the fire side Flame confirmation signal Density of people in front of the gate Actual opening angle of the door And the direction and speed of movement of people or vehicles, and determine an independent passage direction state for each fire door according to preset conditions;

[0085] when If the condition is met for a duration of ≥3 seconds, it is determined to be a two-way passage state;

[0086] when If any of the conditions in the fire door are met and the condition lasts for ≥2 seconds, the fire door is determined to be in a one-way passage state, and the dangerous side and the safe side are determined by comparing the carbon monoxide concentrations on both sides of the fire door.

[0087] when If no personnel or vehicles approach within 2 meters in front of the fire door for 10 consecutive seconds, or if the door's multi-dimensional sensor detects a serious mechanical failure, it is determined to be in a fully locked state.

[0088] The target opening angle is calculated every 0.2 seconds based on a preset priority. Among them, the full-open mode is Half-open mode is The door closer applies a holding torque of 30-50N, and adjusts the torque according to the width of the object being passed. and movement speed Dynamically adjusted; based on the actual angle feedback from the magnetic encoder. A PID controller is used to drive the door closer motor, so that... track The response time is less than 0.5 seconds.

[0089] Thermal imaging cameras use human contour detection algorithms to obtain the location coordinates, contour area, and posture (standing / falling / crawling) of a person; millimeter-wave radar uses clustering tracking (DBSCAN + Kalman filtering) to obtain the target ID, velocity vector, and direction of movement angle; by providing static contours through thermal imaging and motion trajectories through radar, a unique identifier, real-time location, instantaneous speed, direction of movement, and whether a wheelchair / stroller is being carried (determined by the aspect ratio of the contour) can be obtained for each person.

[0090] Following step S4, the method further includes: based on the access status (two-way / one-way / locked) and opening angle (fully open / half open / slightly open) of each fire door, combined with the real-time distribution of personnel and vehicles, an escape route generation and notification scheme based on rules and visualization guidance is developed to solve the problem of emergency evacuation guidance in complex scenarios such as mixed traffic of people and vehicles, dense crowds, and dynamic changes in the fire situation.

[0091] The underground parking garage is divided into several evacuation grids (each grid corresponds to a fire compartment or a critical passage intersection). Based on the door status and sensor data updated in real time in step S4, the system dynamically assigns a safety level (green / yellow / red) to each exit direction in each grid, and generates the optimal escape route accordingly. Then, the route information is synchronously notified to vehicles and personnel through various means such as lights and sounds.

[0092] For any fire door (or passageway intersection), the system directly maps the security level for the four directions (east, south, west, and north) based on the status confirmed in S4:

[0093] Door status Opening angle Safety side smoke conditions grade Color Code meaning Two-way traffic any CO on both sides <50ppm green Green always on Two-way passage is possible and safe. One-way traffic (Danger → Safety) ≥45° CO ≥100ppm on the fire side, <100ppm on the safety side yellow Yellow flashing It's an exit-only road; you can pass, but you need to pass quickly. One-way traffic (Danger → Safety) <45° CO ≥100ppm on the fire side, <100ppm on the safety side orange Orange flashing Passable but narrow, please drive slowly. Fully locked 0° Safety side CO ≥ 150 ppm or high temperature red Red always on No passage allowed, danger. Half-open mode (pedestrian walkway) 45° Safety side CO < 100 ppm Green and yellow Green and yellow alternate Pedestrians may pass sideways; vehicles are prohibited. Full Open Mode (Vehicle) 90° Safety side CO < 100 ppm green Green always on Vehicles have priority

[0094] Note: Each fire door provides only two directions (in and out), but sensors determine which direction is safe. For example, in one-way traffic, the direction from the danger side to the safety side is yellow, and the opposite direction is red.

[0095] The system starts from the current location of each person or vehicle and performs the following breadth-first, grid-by-grid diffusion:

[0096] Get the neighboring grids of the current grid (through the building's predefined connection table).

[0097] Check the status of fire doors between adjacent grids:

[0098] If the door status is red, then the direction cannot be selected; if the door status is green, yellow, orange, or green-yellow, then the direction can be selected, and the safety weight of the direction is recorded (green=1, yellow=2, orange=3, green-yellow=1.5, the smaller the value, the safer); select the direction with the lowest safety weight as the next movement direction, repeat until the preset safety exit (stairwell, outdoor gate) is reached.

[0099] Example: A person is standing in grid A, with three adjacent grids B, C, and D:

[0100] The door to B is green → Weight 1

[0101] The door to C is yellow → Weight 2

[0102] The door to D is red → cannot be selected.

[0103] The system then recommends going to option B.

[0104] In scenarios with multiple people / vehicles: Instead of calculating paths individually for each individual (which would be computationally intensive), the system calculates an optimal exit direction for each grid cell, guiding all people and vehicles within that grid cell in the same direction. This is achieved by dynamically updating the "direction arrows".

[0105] When vehicles and pedestrians share the same space, the system generates different paths based on the grid type and the current gate status:

[0106] Vehicle-only grids (e.g., lanes): Only gates that are fully or partially open but allow vehicle passage (gates in green or green-yellow that allow vehicles) are considered. If a gate in a certain direction only allows pedestrians (e.g., half-open and less than 0.8m wide), then vehicles in that direction are hidden from view within that grid.

[0107] Pedestrian-only grids (such as sidewalks): Only doors with an opening angle of ≥15° and no toxic fumes on the safety side are considered, ignoring vehicle access doors.

[0108] Mixed grid: Displays two guidance messages simultaneously: one for vehicles and one for pedestrians, distinguished by different colors or icons.

[0109] In the same physical space, different modes of transportation can see different escape routes, preventing vehicles from blocking pedestrian exits or pedestrians from accidentally entering the driveway.

[0110] Notification methods for personnel:

[0111] equipment Deployment location Display content Features LED Directional Signs Above each fire door, at passageway intersections The green arrow points to the recommended exit, while the red cross indicates a prohibited direction. High brightness, penetrating smoke (using high-brightness LEDs) Voice broadcast system Zone broadcasting "Please evacuate in the direction of the green arrow, then turn right in 50 meters." The announcement plays in a loop, and the volume automatically adjusts according to ambient noise.

[0112] When the population density is greater than 1 person / m², the system automatically increases the flashing frequency of the arrows to guide the crowd to move in the direction of the flashing arrows; at intersections, a voice relay is set up so that the broadcast of the next area is automatically activated after the previous broadcast is completed, forming a "voice-controlled navigation chain".

[0113] For vehicle notification, LED guidance screens above the lanes are set up in segments (30 meters apart) in each lane. The LED guidance screens display "← Exit" or "↑ Exit Ahead," along with the estimated distance, to guide vehicles. When the queue length exceeds 50 meters, the system displays different information at the head and tail of the queue: the head vehicle is guided to turn left, and the tail vehicle is guided to go straight, achieving dynamic diversion and preventing all vehicles from crowding towards the same exit. When the system detects that a pedestrian and a vehicle are approaching a fire door simultaneously, it triggers an audible and visual alarm (pedestrian side: buzzer + red flashing; vehicle side: LED screen displays "Caution Pedestrian" + speed bump vibration reminder).

[0114] Context Sensor characteristics Response measures An exit was blocked by flue gas. Safety side CO > 150ppm Set all fire doors corresponding to this exit to red locked, and redirect the directional arrows upstream of this area to other exits. A certain passage was extremely crowded. Personnel density > 2 people / m², movement speed < 0.3m / s The voice announcement system broadcasts "Congestion ahead, please turn," and forcibly diverts traffic at the upstream intersection (directing some people to the other side door). Long queues of vehicles Vehicle queue length > 100m 50m upstream from the end of the queue, display "Next Exit, Turn Right" on an LED screen and temporarily open a normally closed vehicle access door (if available). The fire spread rapidly Thermal imaging shows a temperature gradient >15°C crossing the boundary. Immediately switch all fire doors on this boundary to one-way (exit only, no entry) and lock them in the opposite direction. At the same time, all upstream guide arrows should point away from the fire source. Smoke exhaust failure Negative pressure at the exhaust port <20Pa All fire doors were forced to be partially open (to limit the influx of smoke), and a voice prompt was activated to "Bend over, cover your mouth and nose." Door malfunction Door sensor error The gate's status will be forcibly set to red, and backup guidance signs (mobile fluorescent arrow signs will be manually placed by security personnel) will be added within a 10-meter radius in front of and behind it.

[0115] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A multi-sensor fusion-based intelligent control method for fire door linkage, applied to underground parking garages, characterized in that: The control method includes: Step S1: Install multiple sensors in the underground garage to collect real-time status data of the environment and fire doors. Divide the collected data into early warning stage, early confirmation stage, mid-term spread stage and late isolation stage according to the fire situation. Step S2: When the collected data is identified as an early warning stage, the multi-dimensional sensor of the door is switched to high-frequency sampling mode, and the pre-tightening force of the door closer of the fire door around the fire source is adjusted. Step S3: When the collected data is identified as the early confirmation stage, first start the smoke exhaust fan of the fire compartment where the fire source is located, monitor the negative pressure of the smoke exhaust outlet in real time, and after the negative pressure stabilizes, perform the fire door closing operation, close the fire door of the corresponding compartment, and adjust the fire door of the adjacent compartment to a semi-locked state. Step S4: When the collected data is identified as the mid-stage of the spread, a real-time thermal map and movement direction of personnel are constructed based on millimeter-wave radar and thermal imaging cameras. Combined with the smoke concentration inside each fire door, the passage direction and opening angle of each fire door are dynamically adjusted. Based on the identification of geomagnetic sensors and visible light cameras, for passages shared by vehicles and pedestrians, some fire doors are fully opened to allow vehicles to pass, and the fire doors on adjacent pedestrian passages are adjusted to a half-open mode. Step S5: When the collected data is identified as the late isolation stage, the fire doors are closed one by one in order of distance from the fire source. The closing interval for each door is preset. After each fire door is closed, the sealing strip pressure is detected by the door body multi-dimensional sensor. If the pressure is lower than the preset threshold, a secondary closing action is triggered.

2. The multi-sensor fusion intelligent control method for fire door linkage according to claim 1, characterized in that, The criteria for classifying the collected data into early warning stage, early confirmation stage, mid-stage spread stage, and late isolation stage in step S1 based on the fire situation are as follows: Obtain the highest temperature of battery cells in the charging station area. and the rate of temperature rise of battery cells ,when This was determined to be an early sign of thermal runaway; the concentration of total volatile organic compounds (VOCs) measured by the air quality sensor was obtained. ,when If the emission persists for more than 3 seconds, it is determined that the battery is releasing combustible gas; the smoke concentration is then obtained from the smoke concentration sensor. ,when However, if the early confirmation threshold has not yet been reached, it is determined to be the initial stage of smoldering; when any of the above determination conditions are met, the confirmation timer is started, and if the condition disappears within 5 seconds, the warning stage is exited. If it lasts for 5 seconds, it is determined to be the early warning stage; Acquire ultraviolet flame detection signals measured by a multispectral flame detector and infrared flame detection signal Open flame Confirmed, when A smoke concentration ≥0.7 is considered a confirmed open flame; this is based on the smoke concentration measured by the smoke concentration sensor. And the carbon monoxide concentration measured by the carbon monoxide sensor Double verification is performed to determine whether the gas is hazardous, based on the combined value of smoke and CO. When the concentration is ≥1.0, it is considered a flue gas hazard; if 0.7 or If the condition persists for more than 2 seconds, it is considered to be in the early confirmation stage. ； ； in, , The dangerous threshold for smoke concentration. The CO hazard threshold, ; Obtain the carbon monoxide concentration values ​​measured by carbon monoxide sensors in adjacent fire compartments to obtain the CO concentration difference between adjacent fire compartments. Based on the CO concentration difference between adjacent fire compartments CO concentration in adjacent fire compartments To determine whether flue gas has spread across zones, when and It was determined that the flue gas had significantly invaded the adjacent zone; Pre-mark the fire compartment boundary lines, calculate the highest and lowest temperature differences within 1 meter on both sides of the boundary, and determine that the fire has approached or crossed the boundary if the temperature difference is ≥15℃; based on the highest temperature in the thermal imaging within the fire source compartment... and the rate of temperature rise obtained by differentiating the temperature values ​​of the time series. To determine whether the temperature rise in the fire source zone is out of control, when and If the temperature rise in the fire source zone is out of control, it is determined to be in the intermediate spread stage; if any of the above conditions are met, it is determined to be in the intermediate spread stage. The fire zone and adjacent evacuation routes were confirmed to be free of any moving targets and stationary personnel through both thermal imaging cameras and millimeter-wave radar, confirming the evacuation of personnel. Vehicle identification was performed using geomagnetic sensors and visible light cameras to confirm the evacuation of vehicles. Once it is confirmed that the fire is no longer spreading rapidly, the final fire doors are closed in sequence. When all personnel and vehicles have been evacuated and the fire is no longer spreading rapidly, it is considered to be in the late isolation stage. If new personnel are detected entering during the fire door closure process, the process is immediately terminated and the process is reverted to the mid-spread stage.

3. The multi-sensor fusion intelligent control method for fire door linkage according to claim 2, characterized in that, Step S2, which involves adjusting the pre-tightening force of the door closers of the fire doors surrounding the fire source, specifically includes: Based on the location of the fire source, the fire source sensor installation point is used as the center, and all fire doors within a radius of 10m are used to divide the fire source area. If the fire source is located inside the fire compartment, all doors in that compartment and the doors of adjacent compartments that directly face the fire source need to have their door closers preload adjusted. The door closer is a stepper motor driven door closer, and a door closer spring is installed inside the door closer. The preload of the door closer spring is linearly adjusted by a control signal.

4. The multi-sensor fusion intelligent control method for fire door linkage according to claim 2, characterized in that, In step S3, when the collected data is identified as the early confirmation stage, the smoke exhaust fan of the fire compartment where the fire source is located is first started, and the negative pressure at the smoke exhaust outlet is monitored in real time. After the negative pressure stabilizes, the fire door closing operation is performed, closing the fire door of the corresponding compartment and adjusting the fire door of the adjacent compartment to a semi-locked state, specifically including: The fire compartment where the fire source is located is determined. Based on the fire source compartment identification, the smoke exhaust fans of that compartment and adjacent compartments are automatically started. A differential pressure sensor is installed at the smoke exhaust outlet of the smoke exhaust fan. After the smoke exhaust fan start command is issued, the data of the differential pressure sensor is monitored in real time, and the negative pressure value of the smoke exhaust outlet is defined. During normal smoke exhaust, the negative pressure value changes with the fan speed and pipe resistance. Continuously collect the negative pressure at the smoke exhaust outlet, calculate the fluctuation rate and rise rate within the sliding window. When the fluctuation rate is ≤0.1 and the rise rate is ≤5Pa / s, and the duration is ≥2s, record the negative pressure value at this time, and perform the fire door closing operation. Based on the identified fire compartment, a closing command is sent to all fire doors within that compartment. During the closing process, graded torque control is used. The first 0.5 seconds are started with 50% of the rated torque to avoid impact. When the door angle θ≤5°, the torque is switched to 100% to ensure a seal. After closing, the door magnetic sensor verifies whether the latch is in place. If it is not in place, a local audible and visual alarm is triggered, and the door is closed again. The fire doors in the fire compartment adjacent to the fire compartment are adjusted to a semi-locked state. During the closing of the fire doors in the compartment, the negative pressure value of the smoke exhaust outlet is continuously monitored. If the negative pressure of the smoke exhaust outlet drops by more than 30Pa due to the closing of the door, the frequency of the smoke exhaust fan is automatically increased or the valve is opened to maintain the negative pressure value of the smoke exhaust outlet ≥ (0.8 * fluctuation rate) to ensure that the closing action does not significantly reduce the smoke exhaust efficiency. If the negative pressure cannot reach 20Pa within 10 seconds after the smoke exhaust fan starts, it is judged as a smoke exhaust system malfunction. At this time, the door closing operation is forcibly executed, and a "smoke exhaust failure" alarm is reported, prompting personnel to use other passages for evacuation.

5. The multi-sensor fusion intelligent control method for fire door linkage according to claim 2, characterized in that, In step S4, when the collected data is identified as being in the mid-stage of the spread, a real-time thermal map and movement direction of personnel are constructed based on millimeter-wave radar and thermal imaging cameras. Combined with the smoke concentration inside each fire door, the passage direction and opening angle of each fire door are dynamically adjusted. Based on the identification data from geomagnetic sensors and visible light cameras, for passages shared by vehicles and pedestrians, some fire doors are fully opened for vehicle passage, and fire doors on adjacent pedestrian passages are adjusted to a half-open mode. Specifically, this includes: Based on thermal imaging cameras, millimeter-wave radar, multispectral flame detectors, multidimensional door sensors, and carbon monoxide sensors, the carbon monoxide concentration on the fire zone and the safety zone is collected in real time. Temperature on the fire side Flame confirmation signal Density of people in front of the gate Actual opening angle of the door And the direction and speed of movement of people or vehicles, and determine an independent passage direction state for each fire door according to preset conditions; when If the condition is met for a duration of ≥3 seconds, it is determined to be a two-way passage state; when If any of the conditions in the fire door are met and the condition lasts for ≥2 seconds, the fire door is determined to be in a one-way passage state, and the dangerous side and the safe side are determined by comparing the carbon monoxide concentrations on both sides of the fire door. when If no personnel or vehicles approach within 2 meters in front of the fire door for 10 consecutive seconds, or if the door's multi-dimensional sensor detects a serious mechanical failure, it is determined to be in a fully locked state. The target opening angle is calculated every 0.2 seconds based on a preset priority. Among them, the full-open mode is Half-open mode is The door closer applies a holding torque of 30-50N, and adjusts the torque according to the width of the object being passed. and movement speed Dynamically adjusted; based on the actual angle feedback from the magnetic encoder. A PID controller is used to drive the door closer motor, so that... track The response time is less than 0.5 seconds.

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