Electric leakage detection structure adaptive to fire fighting helmets of various specifications

Abstract

The invention discloses an electric leakage detection structure adapted to fire fighting helmets of various specifications, and belongs to the technical field of fire fighting instruments, the structure comprises a helmet, an inner separation belt, an electric leakage detection structure detachably mounted in the helmet, and an auxiliary support structure for enhancing the mounting firmness, the electric leakage detection module adopts an anti-interference zero sequence current transformer and a filter circuit, can accurately identify leakage current not lower than 5mA in a high-temperature and strong electromagnetic interference environment, and has a power frequency interference suppression rate of not less than 95%; a fire-fighting scene electric leakage intelligent grading algorithm is built in the signal processing unit, electric leakage danger can be divided into three levels based on current amplitude, frequency and duration, the signal processing unit has pre-alarm and fault-tolerant processing functions, the signal processing unit, a warning lamp and a buzzer form linked acousto-optic warning logic, and through modular design and standardized installation, debugging and operation and maintenance processes, the electric leakage danger can be classified into three levels. The fire-fighting helmet detection device can adapt to fire-fighting helmets of various specifications, and is high in detection precision, strong in anti-interference capability and stable in installation.

Description

Technical Field

[0001] The invention discloses a leakage detection structure suitable for use with fire helmets of various specifications. The invention belongs to the technical field of fire-fighting equipment, and specifically relates to the technical field of leakage detection structures suitable for use with fire helmets of various specifications. Background Art

[0002] During firefighting and rescue operations, electrical fires frequently occur, and leakage hazards pose a serious threat to the lives of firefighters. Traditional fire helmets mainly focus on basic protection such as impact protection and heat radiation protection, and lack effective adaptive structures for leakage detection. In existing technologies, some solutions that attempt to integrate leakage detection functions have obvious defects: first, poor adaptability, making it difficult to be compatible with fire helmets of different brands and specifications, which limits their promotion and application; second, insufficient detection accuracy, and susceptible to interference in the high temperature and strong electromagnetic interference environment of the fire scene, leading to false alarms and missed alarms; third, unreasonable structural design and poor installation stability, making them unable to withstand vibrations and collisions during the rescue process, and the lack of auxiliary functions such as heat dissipation and battery life, affecting the long-term stable operation of the detection system. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to overcome the existing defects and provide a leakage detection structure that is suitable for use with fire helmets of various specifications, thereby solving the problems in the existing technology of some solutions that attempt to integrate leakage detection functions, such as poor adaptability, insufficient detection accuracy and unreasonable structural design.

[0004] To achieve the above object, the present invention provides the following technical solutions: A leakage detection structure suitable for use with fire helmets of various specifications includes a helmet and an inner partition strip arranged at the top end thereof. The leakage detection structure is detachably installed inside the helmet above the inner partition strip, and an auxiliary support structure is arranged on the side of the leakage detection structure to increase its installation firmness.

[0005] As a preferred technical solution of the present invention, the leakage detection structure includes a mounting shell, which is configured as an arc-shaped structure. The mounting shell is provided with a leakage detection module, a battery pack and an electrical control box. An arc-shaped connecting plate 1 is provided at the bottom end of one side of the mounting shell. The arc-shaped connecting plate 1 is fixed to the inner wall of the helmet by gluing, and a charging interface is provided on the side of the arc-shaped connecting plate 1.

[0006] As a preferred technical solution of the present invention, the leakage detection structure also includes an arc-shaped connecting plate 2, the top of which is fixed to the helmet by gluing, and the bottom of which is installed with a warning light and a switch button, and the electric control box is respectively connected to the warning light and the switch button by wires.

[0007] As a preferred technical solution of the present invention, the auxiliary support structure includes an inner plate, and a clamping plate that cooperates with the inner plate is provided on the other side of the mounting shell, and clamping holes are distributed on the clamping plate, and clamping columns that cooperate with the clamping holes are distributed on the inner plate. An arc-shaped connecting plate three is provided at the bottom end of the clamping column, and the arc-shaped connecting plate three is fixed to the inner wall of the helmet by gluing.

[0008] As a preferred technical solution of the present invention, the electric control box is connected to a buzzer via a connecting wire, and the back of the buzzer is fixed to the inside of the helmet via an adhesive plate.

[0009] As a preferred technical solution of the present invention, heat dissipation fins are provided at positions corresponding to the leakage detection module, the battery pack and the electric control box in the installation shell, and the heat dissipation fins are integrally formed with the installation shell.

[0010] As a preferred technical solution of the present invention, the signal acquisition unit of the leakage detection module is integrated with an anti-interference zero-sequence current transformer. The iron core of the transformer is made of nanocrystalline alloy material and is combined with a filtering circuit. It can accurately identify leakage currents of not less than 5mA in high temperature and strong electromagnetic interference environments in fire scenes, and the suppression rate of power frequency interference signals is ≥95%.

[0011] As an optimal technical solution of the present invention, the signal processing unit of the leakage detection module has a built-in intelligent classification algorithm for leakage in fire scenarios. The algorithm is based on a feature database of building electrical leakage and outdoor cable leakage. It divides the leakage hazard into three levels through multi-dimensional analysis of the current amplitude, frequency, and duration of the collected signal. It also supports updating the algorithm feature parameters on demand through the debugging interface of the electrical control box to adapt to the leakage risk patterns in different regions and scenarios.

[0012] As a preferred technical solution of the present invention, the fire scene leakage intelligent grading algorithm is based on the three-level danger division and has a pre-alarm mechanism for the third-level serious leakage situation. When it is detected that the leakage current increases by more than 10mA within 1 second, the third-level warning is triggered 0.5-1 second in advance, so as to buy time for firefighters to avoid danger.

[0013] As a preferred technical solution of the present invention, the fire scene leakage intelligent grading algorithm forms a linkage logic with the warning light and the buzzer. When the leakage is at level one, only the warning light flashes green at a frequency of times / second; when the leakage is at level two, the warning light flashes yellow at a frequency of 5 times / second, and the buzzer emits a prompt sound at intervals of 1 second; when the leakage is at level three, the warning light flashes red at a frequency of 8 times / second, and the buzzer emits a continuous beep, and the sound and light parameters of each level of warning can be customized through the electrical control box. The fire scene leakage intelligent grading algorithm has a fault-tolerant processing function. When the leakage signal detected for three consecutive times has abnormal fluctuations (such as the instantaneous current exceeds the threshold but the duration is less than 0.1 second), a secondary check will be automatically started. By comparing with historical similar interference signals, it is determined whether it is a false alarm. If it is determined to be a false alarm, the alarm will not be triggered, and the characteristics of such signals will be recorded to optimize subsequent recognition accuracy.

[0014] Compared with the prior art, the present invention has the following beneficial effects: 1. Breakthrough in adaptability: compatible with multiple specifications of helmets, lowering the application threshold Cross-model compatibility: Through the curved surface adaptation design of the arc-shaped mounting shell, the flexible bonding solution of the multiple connecting plates ( / / ) and the adjustable snap-in mechanism of the auxiliary support structure, it can be adapted to more than five types of mainstream fire helmets (covering Type A / B / C), including European, American, and national standards, without the need for destructive modifications such as drilling and cutting on the helmet body. After installation, the original protective performance (impact resistance, temperature resistance) of the helmet is retained at a rate of ≥ 98%. Scenario scalability: Through the customizable algorithm feature parameters, the leakage detection logic can be optimized for more than 10 special scenarios, including commercial buildings, chemical parks, and subway tunnels. For example, in new energy vehicle fire scenarios, it can accurately identify the battery pack's unique DC leakage signal (which traditional equipment is prone to misjudging), solving the pain point that a single detection solution is difficult to adapt to complex firefighting environments. 2. Improved detection performance: high precision and anti-interference, more reliable early warning Detection accuracy in extreme environments: Using nanocrystalline alloy iron core mutual inductor and π-type filter network, the recognition error of 5mA leakage current is ≤0.2mA in an environment with high temperature of 80°C and strong electromagnetic interference of 1000V / m, which is 5 times higher than the accuracy of traditional electromagnetic sensors (error ±1mA). The power frequency interference suppression rate is ≥95%, which can effectively filter out electromagnetic interference from equipment such as welding machines and walkie-talkies (the false alarm rate is controlled below 0.5%). Intelligent classification and pre-alarm: The classification algorithm based on three-dimensional feature analysis can complete the leakage hazard level determination within 0.3 seconds, and trigger the pre-alarm mechanism for level 3 severe leakage (such as phase line grounding). When the current increase exceeds 10mA within 1 second, an early warning will be issued 0.5-1 second in advance. Compared with the traditional threshold-triggered alarm system (response delay ≥ 1 second), this system buys critical avoidance time for firefighters. After actual combat simulation verification, it can reduce the risk of electric shock by more than 60%. 3. Enhanced structural reliability: both stable installation and environmental tolerance are equally important Shock resistance and durability: The triple-fixing structure of "adhesion + buckle + snap connection" ensures that the relative displacement between the detection structure and the helmet is ≤0.5mm in a 5-500Hz vibration environment (simulating firefighting and demolition operations), which is four times more stable than a single-adhesion fixation solution (displacement ≥2mm). After 1,000 plug-in and pull-out installation tests, the snap connection strength retention rate is ≥75%, meeting the practical needs of frequent helmet replacement. Adaptability to extreme environments: The combined design of heat sink fins and titanium-aluminum alloy mounting shell can control the operating temperature of internal electronic components within 60°C (the peak temperature of traditional plastic shell equipment is ≥85°C). Combined with the lithium iron phosphate battery (normal operation between -30°C and 60°C), it can still maintain stable operation in severe cold of -30°C or short-term high temperature shocks of 150°C, solving the industry problems of low-temperature endurance degradation and high-temperature component failure. 4. User experience optimization: balance between low burden and easy maintenance Lightweight and comfortable: The overall structure weight is controlled within 120g (only 1 / 3 of traditional external detection equipment). Through the center of gravity optimization design, the pressure on the top of the head when wearing the helmet is ≤25kPa (traditional equipment ≥40kPa). There is no obvious sense of pressure when wearing it for a long time, which meets the ergonomic needs of firefighters on duty. Convenient Operation and Maintenance: A hot-swappable battery pack design (replacement time ≤ 2 minutes), a component-level maintenance system (module replacement requires no specialized tools), and cloud-based automatic upgrade capabilities reduce annual maintenance time per device to ≤ 4 hours, a three-fold improvement over traditional equipment (≥12 hours). Automatic storage and traceability of maintenance records facilitates full lifecycle management of equipment by firefighters. 5. Significant industrial value: Promoting the intelligent upgrade of firefighting equipment Through the "hardware modularization + algorithm programmability" architecture, this invention provides a universal interface for the expansion of fire helmet functions (such as reserved integration space for gas detection and positioning modules), lowering the research and development threshold of multi-functional firefighting equipment; its standardized installation and operation and maintenance process can increase batch assembly efficiency by more than 50%, significantly reducing the procurement and training costs of fire brigades, and has important demonstration significance for promoting the transformation of firefighting equipment from "passive protection" to "active warning". In summary, the present invention has achieved technological breakthroughs in adaptability, detection accuracy, structural reliability and user experience, effectively solving the problems of poor adaptability, easy false alarms, and unstable installation of existing fire helmet leakage detection equipment, and providing a systematic solution for the safety protection of firefighters in electrical fire scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention; Figure 2 It is a schematic diagram of the first cross-sectional structure of the present invention; Figure 3 It is a schematic diagram of the second cross-sectional structure of the present invention; Figure 4 Schematic diagram of the detection structure of the present invention; Figure 5 It is a schematic diagram of the bottom end of the detection structure of the present invention; 1-Helmet; 2-Inner spacer; 3-Leakage detection structure; 31-Mounting shell; 32-Leakage detection module; 33-Battery pack; 34-Electric control box; 35-Arc-shaped connecting plate 1; 36-Charging port; 37-Arc-shaped connecting plate 2; 38-Warning light; 39-Switch button; 4-Auxiliary support structure; 41-Inner plate; 42-Cardboard; 43-Card hole; 44-Card column; 45-Arc-shaped connecting plate 3; 46-Connecting wire; 47-Buzzer; 48-Adhesive plate; 310-Heating fins. DETAILED DESCRIPTION

[0016] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0017] See also Figure 1-5 , the present invention provides a technical solution: A leakage detection structure suitable for use with fire helmets of various specifications comprises a helmet 1 and an inner spacer band 2 arranged at the top end thereof; a leakage detection structure 3 is detachably installed inside the helmet 1 above the inner spacer band 2 using a quick-release connection structure such as an elastic snap-fit ​​limit groove or a magnetic auxiliary locking assembly, which is convenient for later maintenance and replacement and adapts to the flexible assembly requirements of helmets of different batches and specifications; an auxiliary support structure 4 for enhancing the installation rigidity and seismic resistance is provided on the side of the leakage detection structure 3, which offsets the effects of vibration and impact on the detection structure during firefighting operations through multi-dimensional mechanical compensation.

[0018] 1. Leakage detection structure 3 - core functional unit Arc-shaped mounting shell 31: space adaptation and heat dissipation enhancement The mounting shell is stamped into an arc shape using aviation-grade lightweight alloys such as titanium-aluminum alloys, precisely fitting the internal curved contours of the helmet. While minimizing the space occupied inside the helmet, it maximizes the contact area with the inner wall of the helmet, thereby improving the efficiency of heat conduction. Its inner wall corresponds to the heating area of ​​the leakage detection module 32, battery pack 33 and electronic control box 34. It is integrally molded with high-density heat dissipation fins 310, and the fin spacing is strictly controlled at 2-3mm, forming a "heat sink"-like structure. By simulating the thermal flow field of firefighting scenarios, the fin layout can be optimized with the help of CFD fluid mechanics simulation to ensure that heat is quickly transferred to the helmet shell. Through air convection and radiation heat dissipation, the operating temperature of the internal electronic components is effectively controlled within 60°C. Under the short-term high temperature impact of firefighting scenarios, the peak temperature does not exceed 85°C, ensuring the service life and stability of key components such as lithium batteries and integrated circuits.

[0019] Functional component integration: detection, power supply, and control integration Leakage Detection Module 32: As the core sensing unit, it utilizes an "anti-interference zero-sequence current transformer + high-precision signal conditioning circuit" architecture. The transformer core is made of a nanocrystalline alloy, such as the iron-based nanocrystalline alloy 1K101. A special heat treatment process increases the magnetic permeability to the order of 10^5. Combined with a customized filter circuit consisting of a π-type filter network composed of multilayer ceramic capacitors and high-frequency inductors, it can accurately identify leakage currents of 5mA or higher, even in the presence of strong electromagnetic interference (1000V / m) typical in firefighting scenarios, such as high-voltage cable leakage, electrical equipment short-circuit sparks, and high temperatures of 80°C. It also suppresses 50Hz power frequency interference signals by 95% or higher, ensuring the purity of the collected signal.

[0020] Battery Pack 33: Utilizes a highly safe, high-energy-density, firefighting-specific lithium-ion battery pack, such as lithium iron phosphate (LiFePO4) batteries. Each cell has a capacity of 2000mAh, connected in series or parallel for a total capacity of 5000mAh. A built-in battery management system (BMS) monitors voltage, current, and temperature in real time, and provides overcharge, over-discharge, and short-circuit protection. A low-power circuit design maintains standby power consumption of ≤100μA, enabling continuous inspection operations for over 8 hours on a single charge, meeting the needs of firefighters during regular shifts. The charging port 36 is compatible with the USB-C fast-charging protocol, allowing the helmet to be fully charged to 80% in 30 minutes when returned to the charging cradle.

[0021] Electric Control Box 34: A 32-bit microcontroller based on the ARM Cortex-M4 core, such as the STM32L476RG, integrates signal acquisition, processing, storage, and communication functions. The built-in 256KB flash memory is used to store a database of leakage characteristics for fire protection scenarios, covering current waveforms, frequency, and amplitude characteristics for more than 10 typical fault modes, including building electrical leakage, outdoor cable leakage, and new energy vehicle battery leakage. A 12-bit ADC with a 10kHz sampling rate acquires signals from the leakage detection module. After processing using algorithms such as digital filtering and Fourier transform, the leakage current is analyzed in three dimensions: amplitude, frequency, and duration.

[0022] Installation connection design: dual redundant adhesive fixation + mechanical limit The curved connecting plate 35 at the bottom of one side of the mounting shell 31 is glued to the inner wall of the helmet using 3M fire-fighting high-temperature resistant adhesive model 55256, which operates at temperatures between -40°C and 150°C. The adhesive coating thickness is 0.2-0.3mm, and a dispensing robot precisely controls the width of the coating area to 15mm. The length is adapted to the curvature of the connecting plate, ensuring a bond strength of ≥2MPa in room temperature tensile tests. In a high-temperature environment of 80°C, the shear strength retention rate is ≥80%. Meanwhile, the curved connecting plate 37 at the top of the mounting shell uses a dual-redundancy "adhesion + snap" design for connection to the helmet: the top is fixed with the same type of adhesive, and the bottom is integrated with an elastic snap made of nylon 66, with a load capacity of ≥5N. This snap fits into the preset limit holes on the inner wall of the helmet, doubly limiting the displacement of the mounting shell in both the vertical axial direction and the horizontal circumferential direction of the helmet, thus resolving the problem of single adhesive fixation easily falling off under severe vibration. The warning light 38 integrated at the bottom of the arc-shaped connecting plate 2 37 adopts a high-brightness LED. The red, yellow and green colors can be independently controlled. The switch button 39 has an IP67 waterproof and dustproof rating and can withstand a 50N pressing impact force. It is connected to the electronic control box 34 through a flexible PCB cable to realize the "one-button start and stop + graded warning" interactive function.

[0023] 2. Auxiliary support structure 4 - mechanical strengthening system "Inner plate-clamping plate-clamping column-connecting plate" four-link support mechanism The auxiliary support structure consists of an inner plate 41, a clamping plate 42, a clamping column 44, and an arc connecting plate III 45. It is made of high-strength engineering plastics such as polycarbonate + glass fiber reinforced materials and is injection-molded with a bending strength ≥ 120 MPa. The inner plate 41 fits against the inner wall of the helmet. Through a pre-embedded metal insert made of stainless steel 304, it has an interference fit with the clamping column 44 (diameter 3 mm, length 10 mm, with a knurled surface) with a fit tolerance of H7 / k6. After the clamping column is inserted into the clamping holes 43 (diameter 3.2 mm, hole pitch 15 mm, distributed in a matrix) of the clamping plate 42, self-locking is achieved through the elastic deformation of the plastic, forming a "triangular stable support". The arc connecting plate III 45 is also pasted on the inner wall of the helmet with 3M55256 adhesive, forming a "pin" - shaped installation fulcrum with the arc connecting plate I 35 and II 37, increasing the installation stiffness of the leakage detection structure by more than 3 times. In the environment of a vibration frequency of 5 - 500 Hz and an acceleration of 2g during climbing a fire ladder and demolition operations, the relative displacement between the detection structure and the helmet is ≤ 0.5 mm, ensuring the relative position stability between the current transformer and the helmet and avoiding detection errors caused by mechanical deformation.

[0024] 3. Intelligent Algorithm and Linkage Control - Leakage Classification Warning System Intelligent Classification Algorithm for Leakage in Fire Scenarios The "Database of Electrical Leakage Characteristics of Buildings and Outdoor Cable Leakage" constructed based on big data covers more than 5000 real fire rescue leakage cases, including typical scenarios such as leakage in commercial building distribution boxes, leakage due to damaged municipal cables, and leakage in new energy vehicle charging piles. The algorithm conducts multi-dimensional weighted analysis on the collected signal current amplitude I, frequency f, and duration t (weight coefficients: I = 0.5, f = 0.3, t = 0.2), and divides the leakage risk into three levels: Level 1: Minor Leakage: I ∈ [5 mA, 30 mA), f = 50 Hz ± 2 Hz, t ≤ 5 s, determined as non - urgent hidden dangers such as "slight damage to the cable insulation layer, poor contact"; Level 2: Moderate Leakage: I ∈ [30 mA, 100 mA), f = 50 Hz ± 5 Hz or there is a 100 Hz harmonic component, t ∈ (5 s, 30 s], determined as "aging and breakdown of the insulation layer, precursor to short - circuit"; Level 3: Severe Leakage: I ≥ 100 mA, f has broadband fluctuations of 20 Hz - 1000 Hz, t > 30 s or the current increase rate ΔI / Δt > 10 mA / s, determined as life - threatening risks such as "phase - to - ground short circuit, electrical equipment fire".

[0025] The algorithm supports online updating of the feature database and classification thresholds through the debugging interface of the electronic control box 34, such as the Micro - USB interface, which is compatible with the fire - fighting handheld debugging terminal. For special scenarios such as chemical industrial parks and subway tunnels, the leakage current amplitude threshold and frequency characteristics can be customized to achieve precise adaptation of "one place, one policy" and "one disaster, one policy".

[0026] Early warning and fault tolerance mechanisms: Improving emergency response reliability For level 3 severe leakage, the algorithm has a built-in "current mutation prediction model" to monitor the current change rate dI / dt in real time. When it detects that the current increase exceeds 10mA within 1 second, such as in the early stage of a short-circuit fault, the current suddenly rises from 80mA to 120mA, triggering the pre-alarm logic. By adjusting the algorithm delay parameters 0.5-1 second in advance, the algorithm initiates the level 3 warning according to the response needs of different scenarios, thereby gaining a critical time window for firefighters to evacuate the dangerous area.

[0027] To prevent false alarms caused by electromagnetic interference and transient induced currents, the algorithm incorporates a three-level fault-tolerance verification mechanism. If three consecutive abnormal fluctuations are detected, such as a transient current I_max = 150mA but with a duration t < 0.1s, it is identified as electromagnetic pulse interference, and the "historical interference signal comparison - wavelet transform denoising - secondary acquisition verification" process is automatically initiated. By using the stored signatures of over 100 typical interference signals, such as welding sparks, electrostatic discharge, and electromagnetic radiation from two-way radios, the dynamic time warping (DTW) algorithm is used to perform a similarity match. If a match exceeds 80%, interference is identified. If a false alarm is identified, the audible and visual alarms are not triggered, and the interference signature is stored in the local database for optimization of subsequent recognition models. This results in a false alarm rate of less than 0.5% based on statistics from one million simulation tests.

[0028] Sound and light linkage logic: multi-modal warning output The electric control box 34 uses PWM pulse width modulation technology to accurately control the flashing frequency of the warning light 38 and the sound pattern of the buzzer 47 to achieve: Level 1 slight leakage: The warning light flashes green 3 times per second with a duty cycle of 30%, and the buzzer is silent to avoid interfering with the firefighters' routine communications; Level 2 moderate leakage: The warning light flashes yellow 5 times per second with a duty cycle of 50%, and the buzzer emits a "beep-beep" tone with a 1-second interval and a sound pressure level of 85dB and a frequency of 1kHz; Level 3 severe leakage: The warning light is solid red at a frequency of 8 times / second with a duty cycle of 100%. The buzzer emits a continuous beep of 95dB at a frequency of 2kHz. It has a sound level gradient function, linearly increasing from 85dB to 95dB to prevent sudden strong sounds from damaging the firefighters' hearing.

[0029] All sound and light parameters can be customized through the key combination of the electric control box 34, such as long pressing the switch button 39 + short pressing the adjustment key, or the external debugging terminal, such as adjusting the warning light color, flashing frequency, buzzer volume and tone, to meet the communication standards of different fire brigades and individual sensory needs.

[0030] 3.Buzzer integration: sound warning enhancement solution The electronic control box 34 is connected to the buzzer 47 via a high-temperature resistant shielded wire with silver-plated copper wire and Teflon insulation layer, which can withstand temperatures of 200°C. The buzzer adopts a "piezoelectric ceramic + resonance cavity" structure. The back of the buzzer is fixed to the earmuff area inside the helmet 1 via a fire-specific adhesive plate 48 with a silicone base and acrylic pressure-sensitive adhesive. The adhesive strength is ≥1.5N / cm². This ensures that the sound warning is ≥75dB at the firefighter's ear when the background noise in a noisy fire environment is ≥100dB. It is 10cm away from the buzzer, achieving "sound and light coordination and precise warning."

[0031] Three technical effect verifications - through simulated fire scene tests Adaptability test: Five different specifications of fire helmets covering European, American, and national standard Type A / B / C were selected. The structures were assembled and tested according to the installation process. The internal space occupancy rate of the helmet after installation was tested by a three-coordinate measuring instrument, and the wearing comfort was tested with a head mold pressure distribution test, with a peak pressure of ≤25kPa, verifying that the adaptability was good and did not affect the original protective performance and wearing experience of the helmet.

[0032] Detection accuracy test: In a fire electrical safety test chamber, a high temperature of 80°C, 1000V / m electromagnetic interference, and an adjustable leakage current of 5mA-500mA were simulated to test the leakage detection module's recognition error for leakage currents of different amplitudes and frequencies. The results showed that the recognition error of 5mA leakage current was ≤0.2mA, and the recognition error of 100mA leakage current was ≤1mA, meeting the requirements for accurate detection in fire scenarios.

[0033] Earthquake resistance and reliability testing: A fire helmet vibration test bench was used to simulate 5-500Hz swept frequency vibration, 2g acceleration, and duration of 30 minutes. After the test, the structure was inspected for loose or falling parts, electrical connections were normal, and leakage detection accuracy decreased by ≤3%. 1000 plug-in and installation tests were conducted to simulate the replacement of helmets from different batches. The adhesive strength retention rate was ≥75%, and the auxiliary support structure was reliably connected, verifying the installation stability and durability.

[0034] Actual scenario simulation: In a 1:1 building fire simulation training facility, including scenarios such as short-circuit fires, cable leakage, and electrical equipment failures, firefighters were organized to conduct actual combat drills wearing helmets with integrated detection structures. The results showed that the leakage classification warning response time was ≤0.3s, from the current mutation to the triggering of the sound and light warning. The pre-alarm mechanism effectively gained 0.8-1.2s of risk avoidance time for firefighters. The fault-tolerant mechanism successfully filtered out ≥98% of false alarm sources such as welding sparks and intercom interference, verifying the practicality and reliability of the system in real firefighting scenarios.

[0035] Standardization of the entire process from "installation-debugging-operation and maintenance" Installation process: modular step-by-step assembly to ensure accuracy and efficiency Preprocessing stage Using a dust-free cloth dampened with 99.5% anhydrous ethanol, wipe three times the 10 cm x 15 cm area above the spacer tape within the helmet's inner wall mounting area, the auxiliary support structure attachment area, and the buzzer mounting area to remove release agent, oil, and dust. After wiping, let the surface sit for 5 minutes to ensure it is completely dry. Use an infrared thermometer to confirm that the surface temperature is consistent with the ambient temperature to prevent residual moisture from affecting bond strength. Use a laser locator with an accuracy of ±0.1mm to mark the installation reference line on the inner wall of the helmet: based on the central axis of the top of the helmet, mark the adhesive area of ​​the arc-shaped connecting plate 35 with a width of 15mm and an arc that matches the inner wall of the helmet, and mark the positioning point of the card column 44 at the corresponding position of the auxiliary support structure to ensure that the concentricity error between the mounting shell 31 and the helmet is ≤1mm. Core component installation Leakage detection structure main body fixed: Curved connecting plate - 35 pasting: Use a dispensing gun to evenly apply 3M55256 adhesive at a rate of 0.05g / cm² to the back of the connecting plate, attaching it to the inner wall of the helmet along the reference line. Use a silicone pressing block with a hardness of 60ShoreA to apply 5N pressure for 30 seconds to ensure that the adhesive completely penetrates the contact surface. Fix the arc-shaped connecting plate 2 37: Apply the same type of adhesive on the top, align the elastic buckle at the bottom with the preset limit hole of the helmet with a diameter of 4mm, apply an axial force of 3N to complete the buckle locking, and use a tensile tester to test the buckle bonding force to be ≥5N. Auxiliary support structure assembly: Align the latching posts 44 of the inner plate 41 with the latching holes 43 of the latching plate 42. Press vertically with a force of 8-10N to complete the connection. Use a torque wrench to check that the torsional resistance is ≥ 0.5N·m after connection to ensure it does not loosen in a vibrating environment. The attachment process for the curved connecting plate 3 45 is the same as for the connecting plate 1. After attachment, use a level to calibrate the parallelism between the inner plate 41 and the mounting shell 31 to ensure the error is ≤ 0.5mm. Buzzer and cable layout: Buzzer 47 is secured to the inside of the helmet earcup via adhesive plate 48, 3-5 cm from the center of the ear canal. The shielded connecting cable is routed along the helmet's inner wall in a reserved cable trough and secured with high-temperature ties (rated at 150°C) at 5 cm intervals to prevent the cable from swaying and rubbing against the helmet, which can cause noise. The cable connector uses gold-plated terminals with a plug-in / plug-out life of 1000 or more, connecting to the electrical control box 34 to ensure reliable electrical contact. Special helmet adaptation treatment: For helmets with protrusions or irregular structures on some inner walls, a silicone gasket with a thickness of 0.5-1mm and a hardness of 40ShoreA can be installed between the curved connecting plate and the inner wall of the helmet. The deformation of the gasket compensates for the structural differences, ensuring that the adhesive surface fits tightly and the bonding strength is not less than 1.8MPa. Standardization of installation tools: Clearly list and specifications of tools required for installation. For example, the dispensing gun must be equipped with a needle with a diameter of 0.8mm to ensure uniform application of the adhesive. The silicone pressure block must have a contact surface with a curved fit to avoid damage to the helmet surface when pressing.

[0036] System debugging: hierarchical verification to adapt to scenario requirements Basic function self-test Pressing the on / off button 39 causes the system to enter self-test mode. Warning lights 38 illuminate red, yellow, and green for one second each, and the buzzer emits a three-step "beep-beep-beep" tone, completing the hardware function check. If a component is malfunctioning, such as the warning light not illuminating, the LED indicator built into the electronic control box 34 flashes red, indicating the corresponding component failure, facilitating quick troubleshooting. Parameter calibration and algorithm update Connect the fire-fighting dedicated debugging terminal running Windows CE system through the Micro-USB debugging interface, read the device firmware version, and confirm that it matches the latest algorithm version, such as V2.3.1, which supports leakage feature recognition of new energy vehicles. Leakage threshold calibration: In a laboratory environment, connect a standard current source with an accuracy of ±0.1mA, input currents of 5mA, 30mA, and 100mA in sequence, and calibrate the thresholds of each level through the terminal software to allow an error of ±2mA to ensure accurate first / second / third level leakage determination. Algorithm feature parameter update: For chemical park scenarios, import the "Chemical Equipment Leakage Feature Package" through the terminal and customize the frequency feature threshold. For example, adjust the harmonic component ratio threshold from 10% to 15% to adapt to the leakage patterns of motors and pump equipment in this scenario. Customized sound and light parameters According to the fire department's communication specifications, the following settings were set through the debugging terminal: the first-level warning green light flashes 3 times / second, the second-level warning yellow light has a duty cycle of 50%, and the third-level warning red light has a brightness of 800cd / m²; the second-level buzzer tone interval is 1 second, and the third-level continuous buzzer sound pressure level is 95dB. After the settings were set, the terminal simulated leakage signals to verify that the sound and light outputs met expectations. Interference source simulation test: During debugging, dedicated equipment can be used to simulate common interference signals in firefighting scenarios, such as electromagnetic radiation from 800MHz walkie-talkies and transient pulses generated by welding sparks, to verify whether the fault-tolerant processing function can effectively filter out interference and ensure detection accuracy in complex electromagnetic environments. Multi-scenario algorithm switching demonstration: Detailed explanation of how to quickly switch algorithm modes for different scenarios through the debugging terminal. For example, when switching from the "building electrical scenario" to the "new energy vehicle scenario", the terminal interface provides operation steps and parameter change feedback to facilitate actual operation.

[0037] Operation and maintenance system: full life cycle management to ensure reliability Daily maintenance before daily duty Appearance inspection: Visually confirm that the connection plates are not warped, the gap between the adhesive edges is ≤0.2mm, the snap-on structure is not loose, the cables are not damaged, and there is no dust accumulation on the heat sink fins. Clean them with a soft brush. Functional test: Short-press the switch button 39 to start a quick test for 3 seconds to verify that the warning light and buzzer respond normally. Use the power indicator integrated in the switch button to confirm that the battery pack 33 has a charge level of ≥ 80%. If the charge level is insufficient, use a matching fast charger with a 5V / 2A output to replenish the battery. Environmental adaptability check: Before working in a high temperature and high humidity environment such as a garage in summer, use an infrared thermometer to check the surface temperature of the installation shell to be ≤40°C to prevent premature degradation of the battery pack due to high temperature. Regular maintenance every 3 months Performance calibration: The equipment is sent to the fire equipment testing station and tested for anti-interference performance in the standard electromagnetic compatibility laboratory GB / T17626.2-2018 to ensure that the power frequency interference suppression rate is ≥ 95%. The equipment is also tested in a high and low temperature chamber with a cycle test of -30°C to 80°C for 10 cycles to verify that the leakage detection error is ≤ 5% under extreme temperatures. Structural strength re-inspection: Use a tensile gauge to test the bonding strength of each connecting plate to be ≥1.5MPa. If it is lower than the threshold, replace the adhesive and re-paste it; after passing the 10-500Hz sweep frequency test on the vibration test bench, check that the snap-on structure has no plastic deformation and the electrical connection resistance is ≤0.1Ω. Algorithm iteration: Connect to cloud servers to support 4G / NB-IoT communications, automatically update the leakage feature database with ≥50 real cases added each month, and ensure the algorithm's ability to identify leakage patterns of new electrical equipment such as hydrogen-powered fire trucks. Fault repair emergency response A "component-level replacement" maintenance system has been established: When the leakage detection module 32 fails, the M2.5×8mm fixing screws of the mounting housing 31 are removed using a dedicated Allen wrench, and the module is replaced and recalibrated. When the battery pack 33 reaches the end of its lifespan after 500 or more charge and discharge cycles, it can be directly replaced with a hot-swappable spare battery pack in 2 minutes or less, ensuring rapid restoration of the equipment to operational status. Maintenance records are automatically stored in the electronic control box's storage module, with a capacity of 100 or more entries, facilitating historical equipment status tracing.

[0038] Emergency maintenance in extreme environments: If a temporary equipment failure occurs at a high-temperature fire scene or in a cold environment, a spare heating plate with an operating temperature of 50-60°C can be used to auxiliary heat the battery pack, or the installation shell can be wrapped with an insulating sleeve to reduce the impact of heat, ensuring normal operation of the equipment in a short period of time and buying time for evacuation. Calibration process after component replacement: Clarify the calibration steps after replacing core components such as leakage detection modules and battery packs. For example, after replacing a module, it is necessary to reconnect the standard current source for three-level threshold calibration. The calibration data must be uploaded to the management system through the debugging terminal for archiving to ensure that the performance meets the standards after replacement.

[0039] Through the above-mentioned standardized process, full-chain quality control from installation to operation and maintenance is achieved, ensuring that the leakage detection structure maintains stable and reliable working performance throughout the entire life cycle of firefighting and rescue, and providing firefighters with continuous and effective leakage safety warnings.

[0040] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A leakage detection structure adapted for use with fire helmets of various specifications, comprising a helmet (1) and an inner spacer (2) arranged at the top end thereof, characterized in that: A leakage detection structure (3) is detachably installed inside the helmet (1) above the inner spacer (2), and an auxiliary support structure (4) for increasing the installation firmness of the leakage detection structure (3) is provided on the side surface.

2. The leakage detection structure adapted for use with fire helmets of various specifications according to claim 1, characterized in that: The leakage detection structure (3) includes a mounting shell (31), the mounting shell (31) is configured as an arc-shaped structure, and the mounting shell (31) is provided with a leakage detection module (32), a battery pack (33), and an electric control box (34). An arc-shaped connecting plate (35) is provided at the bottom end of one side of the mounting shell (31), and the arc-shaped connecting plate (35) is fixed to the inner wall of the helmet (1) by gluing. A charging interface (36) is provided on the side of the arc-shaped connecting plate (35).

3. The leakage detection structure adapted for use with fire helmets of various specifications according to claim 2, characterized in that: The leakage detection structure (3) further includes an arc-shaped connecting plate (37) having a top end fixed to the helmet (1) by gluing, a warning light (38) and a switch button (39) being mounted on the bottom end of the arc-shaped connecting plate (37), and the electric control box (34) being connected to the warning light (38) and the switch button (39) respectively by wires.

4. The leakage detection structure adapted for use with fire helmets of various specifications according to claim 2, characterized in that: The auxiliary support structure (4) includes an inner plate (41), and a clamping plate (42) matching the inner plate (41) is provided on the other side of the mounting shell (31), and clamping holes (43) are distributed on the clamping plate (42), and clamping columns (44) matching the clamping holes (43) are distributed on the inner plate (41), and an arc-shaped connecting plate (45) is provided at the bottom end of the clamping column (44), and the arc-shaped connecting plate (45) is fixed to the inner wall of the helmet (1) by gluing.

5. The leakage detection structure adapted for use with fire helmets of various specifications according to claim 2, characterized in that: The electric control box (34) is connected to a buzzer (47) via a connecting line (46), and the back of the buzzer (47) is fixed to the inside of the helmet (1) via an adhesive plate (48).

6. The leakage detection structure adapted for use with fire helmets of various specifications according to claim 2, characterized in that: Positions in the installation shell (31) corresponding to the leakage detection module (32), the battery pack (33), and the electric control box (34) are all provided with heat dissipation fins (310), and the heat dissipation fins (310) are integrally formed with the installation shell (31).

7. The leakage detection structure adapted for use with fire helmets of various specifications according to claim 1, characterized in that: The signal acquisition unit of the leakage detection module (32) is integrated with an anti-interference type zero-sequence current transformer. The iron core of the transformer is made of nanocrystalline alloy material. In combination with a filter circuit, it can accurately identify a leakage current of not less than 5 mA in a high temperature and strong electromagnetic interference environment in a fire scene, and the suppression rate of the power frequency interference signal is ≥95%.

8. The leakage detection structure adapted for use with fire helmets of various specifications according to claim 1, characterized in that: The signal processing unit of the leakage detection module (32) has a built-in intelligent classification algorithm for leakage in fire scenarios. The algorithm is based on a feature database of building electrical leakage and outdoor cable leakage. Through multi-dimensional analysis of the current amplitude, frequency, and duration of the collected signal, the leakage hazard is divided into three levels. The algorithm also supports updating the algorithm feature parameters on demand through the debugging interface of the electric control box (34) to adapt to the leakage risk patterns of different regions and scenarios.

9. The leakage detection structure adapted for use with fire helmets of various specifications according to claim 8, characterized in that: The fire scene leakage intelligent grading algorithm is based on the three-level danger classification and has a pre-alarm mechanism for the third-level serious leakage situation. When it is detected that the leakage current increases by more than 10mA within 1 second, the third-level warning is triggered 0.5-1 second in advance, buying time for firefighters to avoid danger.

10. The leakage detection structure adapted for use with fire helmets of various specifications according to claim 9, characterized in that: The fire scene leakage intelligent grading algorithm forms a linkage logic with the warning light (38) and the buzzer (47). When the leakage is at level one, only the warning light (38) flashes green at a frequency of 3 times / second; when the leakage is at level two, the warning light (38) flashes yellow at a frequency of 5 times / second, and the buzzer (47) emits a prompt sound at intervals of 1 second; when the leakage is at level three, the warning light (38) flashes red at a frequency of 8 times / second, and the buzzer (47) emits a continuous buzzing sound. The sound and light parameters of each level of warning can be customized through the electric control box (34). The fire scene leakage intelligent grading algorithm has a fault-tolerant processing function. When the leakage signal detected for three consecutive times has abnormal fluctuations, a secondary check will be automatically started to determine whether it is a false alarm by comparing it with the historical similar interference signal. If it is determined to be a false alarm, the alarm will not be triggered, and the characteristics of this type of signal will be recorded to optimize the subsequent recognition accuracy.

Images