A mine respiratory protection equipment air supply safety early warning method and system

Abstract

This invention relates to the field of air supply control technology and discloses a method and system for air supply safety early warning of mining respiratory protective equipment. The method includes: collecting breathing pressure data and battery voltage data, and performing respiratory cycle identification to obtain a wearing confirmation result. When effectively worn, the inspiratory negative pressure amplitude and expiratory recovery amplitude are extracted to obtain the basic air supply level. When the battery voltage data meets the undervoltage warning condition, air supply is rechecked during the expiratory stabilization phase, and rechecked air supply data is collected. The rechecked air supply data, inspiratory negative pressure amplitude, and expiratory recovery amplitude are used to determine the cause of air supply limitation. Based on the battery voltage data and the rechecked air supply data, the remaining air supply is determined to obtain the evacuation air supply result. A safe air supply disposal result is generated based on the air supply limitation cause determination result and the evacuation air supply result. This invention achieves necessary breathing assistance and protection of remaining air supply time, improving the respiratory protection safety of the wearer during evacuation from a dusty environment.

Description

Technical Field

[0001] This invention relates to the field of air supply control technology, and more specifically, to a method and system for early warning of air supply safety for mining respiratory protective equipment. Background Technology

[0002] Mining respiratory protective equipment is used for individual respiratory protection in dusty environments underground in coal mines. It typically uses filter components to block coal dust particles and air supply components to reduce the wearer's inhalation resistance. With the increasing intensity of underground operations such as tunneling, coal mining, and material handling, relying solely on self-priming dust masks can easily lead to a feeling of stuffiness, and wearers risk removing or improperly fitting them during prolonged work. To increase the willingness to wear them continuously, existing technology has developed intelligent air-supply masks that can detect breathing pressure and provide auxiliary air supply. This type of equipment can improve breathing comfort to a certain extent and reduce the risks of discontinuous wear in high-dust environments.

[0003] In existing technologies, for example, Chinese invention patent application CN119925846A discloses an intelligent air-supply mask. This mask uses a pressure sensor to detect the gas pressure within the breathing space, and a control device controls the air-supply component based on the gas pressure data. This solution can provide auxiliary air supply according to breathing conditions, but the focus is on reducing inhalation resistance and improving wearing comfort. In actual use in coal mines, changes in breathing space pressure can also be affected by changes in work intensity, filtration resistance, wearing conditions, fan operation, and battery power. If air supply is adjusted solely based on changes in breathing pressure, it is difficult to distinguish between changes in normal breathing needs and a decrease in the equipment's air supply capacity. Furthermore, when battery power is insufficient, continued high-load air supply may shorten the effective air supply time, thus affecting the wearer's safe evacuation from dusty environments.

[0004] Therefore, it is necessary to design a safety early warning method and system for ventilation of mine respiratory protective equipment to solve the problems existing in the current technology. Summary of the Invention

[0005] In view of this, the present invention proposes a method and system for early warning of ventilation safety for mining respiratory protective equipment, which aims to solve the problem that it is difficult to distinguish between increased working load, increased filter resistance, wear leakage and fan abnormality when adjusting ventilation based solely on changes in breathing pressure under low-pressure conditions in coal mines.

[0006] This invention proposes a method for safety early warning of air supply in mining respiratory protective equipment, comprising: Collect respiratory pressure data and battery voltage data, identify the respiratory cycle from the respiratory pressure data, and obtain a wearing confirmation result; When the wearing confirmation result is effective wearing, the inspiratory negative pressure amplitude and expiratory recovery amplitude of the breathing pressure data are extracted to obtain the basic air supply level, and air is supplied according to the basic air supply level; When the battery voltage data meets the undervoltage warning condition, a verification air supply is performed during the expiratory stabilization phase, and verification air supply data is collected. The verification air supply data includes fan operating status data and respiratory pressure response data. The air supply data, inhalation negative pressure amplitude and exhalation recovery amplitude are reviewed to determine the cause of air supply limitation, and the result of the air supply limitation determination is obtained. The result of the air supply limitation determination is the result of increased workload, increased filter resistance, wear leakage or abnormal fan. Based on the battery voltage data and the verified air supply data, the remaining air supply is determined to obtain the evacuation air supply result; A safe air supply handling result is generated based on the determination result of the air supply limitation cause and the evacuation air supply result; when the evacuation air supply result is that the air supply can be maintained, normal air supply is carried out according to the determination result of the air supply limitation cause; when the evacuation air supply result is that the air supply is limited, continuous high-level air supply is prohibited, and evacuation air supply is carried out according to the determination result of the air supply limitation cause.

[0007] Furthermore, the undervoltage warning conditions include: the battery voltage data is not higher than the undervoltage warning voltage, or the rate of decrease of the battery voltage data is not less than the undervoltage decrease rate threshold.

[0008] Furthermore, determining the expiratory stabilization phase includes: Identify the pressure stabilization segment after expiratory recovery based on the respiratory pressure data; When the pressure fluctuation amplitude of the pressure stabilization segment is less than the stabilization amplitude threshold and continues to reach the stabilization duration threshold, it is determined to be the exhalation stabilization stage and the air delivery is rechecked.

[0009] Furthermore, processing the verified air supply data includes: The fan operating status data includes fan operating current and fan speed feedback, and the breathing pressure response data includes pressure increment and pressure drop time. The pressure during the stable expiratory phase before the start of the verification air supply is used as the verification reference pressure. The pressure increment is obtained based on the pressure rise relative to the verification reference pressure during the verification air supply period. The pressure drop duration is obtained based on the duration it takes for the pressure to return to the allowable range of the verification reference pressure after the verification air supply ends. Under the same verification air supply level, the air supply response is obtained based on the pressure increment, fan operating current, and fan speed feedback. The filter resistance characterization is obtained based on the increase in fan operating current and the decrease in air supply response. The leakage attenuation characterization is obtained based on the comparison between the pressure drop duration and the leakage duration threshold.

[0010] Furthermore, when determining the cause of air supply limitation, the following should be considered: If the fan speed feedback is lower than the speed feedback threshold, an abnormal fan result is obtained. If the fan speed feedback is not lower than the speed feedback threshold, the air supply response is lower than the response threshold, and the pressure drop time is shorter than the leakage time threshold, the wearing leakage result is obtained. If the fan speed feedback is not lower than the speed feedback threshold, the fan operating current increases, the air supply response decreases, and the pressure drop time is not shorter than the leakage time threshold, the result of increased filtration resistance is obtained. If the fan speed feedback is not lower than the speed feedback threshold, the inhalation negative pressure amplitude increases, the air supply response volume does not decrease, and the exhalation recovery amplitude does not decrease, the result of increased workload is obtained.

[0011] Furthermore, when determining the remaining air supply, the following should be considered: The evacuation descent speed threshold is determined based on the rate of decrease in battery voltage data, the fan operating current in the verified air supply data, and the minimum safe air supply level. When the rate of decrease of the battery voltage data is less than the evacuation rate threshold, the evacuation air supply result is that the air supply can be maintained. When the rate of decrease of the battery voltage data is not less than the evacuation rate threshold, the evacuation air supply result is restricted air supply.

[0012] Furthermore, the general air supply includes: allowing an increase in the air supply level as a result of increased workload, maintaining the basic air supply level and outputting a filter maintenance warning as a result of increased filter resistance.

[0013] Furthermore, the evacuation air supply includes: using the lowest safe air supply level as the basic air supply state, and prohibiting continuous high-level air supply based on the increase in work load.

[0014] Furthermore, the evacuation air supply also includes: When the workload increases and the suction negative pressure amplitude exceeds the safe negative pressure threshold, short-term suction compensation air supply is performed. When the filter resistance increases and the suction negative pressure amplitude exceeds the safe negative pressure threshold, continuous high-speed air supply is restricted and short-term suction compensation air supply is performed. If a leak occurs while wearing the garment, maintain minimum safe airflow and issue a re-wearing warning. If the fan malfunctions, stop normal air supply and issue a shutdown and evacuation warning.

[0015] Compared with existing technologies, the beneficial effects of this invention are as follows: By identifying the respiratory cycle and confirming the effective wearing status through respiratory pressure data, the basic air supply level is determined based on the inspiratory negative pressure amplitude and expiratory recovery amplitude, enabling the mining respiratory protective equipment to provide normal auxiliary air supply on the basis of effective wearing, reducing ineffective air supply when not worn or worn abnormally; after the battery voltage data meets the undervoltage warning condition, the air supply volume is no longer increased simply based on changes in respiratory pressure, but is rechecked during the expiratory stabilization phase, and the cause of air supply limitation is determined by combining the fan operating status data and respiratory pressure response data, thereby differentiating the working negative pressure. In different scenarios such as increased load, increased filter resistance, wear leakage, and fan malfunction, the system avoids misinterpreting increased filter resistance, wear leakage, or fan malfunction as normal increased breathing demand. At the same time, it obtains the evacuation air supply result based on battery voltage data and verified air supply data. When air supply can be maintained, normal air supply is provided. When air supply is limited, continuous high-speed air supply is prohibited and evacuation air supply is switched. In this way, it can balance necessary breathing assistance and remaining air supply time in underground operation scenarios with insufficient battery power, reduce the risk of air supply time shortening too quickly due to continuous high-load air supply, and improve the respiratory protection safety of the wearer during the evacuation process from the dusty environment.

[0016] On the other hand, this application also provides a ventilation safety early warning system for mining respiratory protective equipment, used to apply the ventilation safety early warning method for the aforementioned mining respiratory protective equipment, including: The acquisition unit is used to acquire respiratory pressure data and battery voltage data, identify the respiratory cycle from the respiratory pressure data, and obtain a wearing confirmation result. The first processing unit is used to extract the inspiratory negative pressure amplitude and expiratory recovery amplitude of the breathing pressure data when the wearing confirmation result is effective wearing, to obtain the basic air supply level, and to supply air according to the basic air supply level. The second processing unit is used to perform a re-verification of the air supply during the stabilization phase of the exhalation when the battery voltage data meets the undervoltage warning condition, and to collect the re-verification air supply data. The first judgment unit is used to determine the cause of air supply limitation based on the verified air supply data, inhalation negative pressure amplitude and exhalation recovery amplitude, and to obtain the result of the air supply limitation cause determination. The second judgment unit is used to judge the remaining air supply based on the battery voltage data and the verified air supply data, and obtain the evacuation air supply result. The output unit is used to generate a safe air supply handling result based on the determination result of the air supply limitation cause and the evacuation air supply result.

[0017] It is understandable that the aforementioned ventilation safety early warning methods and systems for mine respiratory protective equipment have the same beneficial effects, and will not be elaborated upon here. Attached Figure Description

[0018] The accompanying drawings are used to illustrate the technical solutions of the present invention and do not constitute a limitation on the scope of protection of the present invention. The process nodes, regional relationships, and functional block diagrams in the drawings are used to illustrate the implementation methods of the embodiments of the present invention. In the drawings: Figure 1 A flowchart of a safety early warning method for air supply in mining respiratory protective equipment provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of a mine respiratory protective equipment provided in an embodiment of the present invention; Figure 3 A flowchart of the undervoltage verification air supply and evacuation air supply control for mining respiratory protective equipment provided in this embodiment of the invention; Figure 4 Functional block diagram of the air supply safety early warning system for mining respiratory protective equipment provided in this embodiment of the invention; The components include: 1. Mask body; 2. Filter box; 3. Air outlet valve; 4. Battery compartment; 5. Air supply chamber; 6. Fan; 7. Sound-transmitting area. Detailed Implementation

[0019] The specific embodiments of the present invention will now be described with reference to the accompanying drawings. These embodiments are used to illustrate the technical solutions of the present invention and do not limit the scope of protection of the present invention. Unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0020] In some embodiments of this application, see Figure 1 As shown, this application proposes a method for providing a safety early warning system for the air supply of mining respiratory protective equipment, comprising: S100: Collects respiratory pressure data and battery voltage data, identifies the respiratory cycle from the respiratory pressure data, and obtains a wearing confirmation result.

[0021] S200: When the wearing confirmation result is that the wearing is effective, the inspiratory negative pressure amplitude and expiratory recovery amplitude of the breathing pressure data are extracted to obtain the basic air supply level, and air is supplied according to the basic air supply level.

[0022] S300: When the battery voltage data meets the undervoltage warning conditions, the system performs a verification air delivery during the stabilization phase of exhalation, and collects verification air delivery data, which includes fan operating status data and respiratory pressure response data.

[0023] S400: Determine the cause of air supply limitation by reviewing the air supply data, inhalation negative pressure amplitude and exhalation recovery amplitude, and obtain the result of the air supply limitation cause determination. The result of the air supply limitation cause determination is the result of increased operating load, increased filter resistance, leakage of clothing, or abnormal fan.

[0024] S500: Determines the remaining air supply based on battery voltage data and verified air supply data to obtain the evacuation air supply result.

[0025] S600: Generates a safe air supply handling result based on the determination of the cause of air supply limitation and the result of evacuation air supply. When the evacuation air supply result indicates that air supply can be maintained, normal air supply is carried out according to the determination of the cause of air supply limitation. When the evacuation air supply result indicates that air supply is limited, continuous high-pressure air supply is prohibited, and evacuation air supply is carried out according to the determination of the cause of air supply limitation.

[0026] See Figure 2 As shown, Figure 2 This is a schematic diagram of the structure of a mining respiratory protective equipment provided in an embodiment of the present invention. The mining respiratory protective equipment may include a mask body 1, a filter cartridge 2, an exhaust valve 3, a battery compartment 4, an air supply chamber 5, a fan 6, and a sound-transmitting zone 7. The mask body 1 is used to cover the wearer's mouth and nose, forming a breathing space near the wearer's mouth and nose. The filter cartridge 2 is located on the air inlet side of the mask body 1 and is used to filter the external air entering the mask body 1. Dust accumulation or blockage in the filter cartridge 2 will affect the air supply resistance and breathing pressure response. The exhaust valve 3 is used to expel exhaled gas during exhalation and affects the pressure stabilization process after exhalation recovery. The battery compartment 4 is used to house the power supply battery, and the battery voltage data can be obtained from the terminal voltage of the power supply battery in the battery compartment 4. The air supply chamber 5 is connected to the breathing space inside the mask body 1, forming an air supply channel driven by the fan 6. The fan 6 is used to supply air to the air supply chamber 5 and the breathing space. The operating current and speed feedback generated by the fan 6 during operation can be used as fan operating status data. The sound-transmitting zone 7 is used to improve the voice transmission effect when wearing the mask. This embodiment does not limit the specific shape, installation angle, or connection structure of the above-mentioned components. Figure 2 The structure shown illustrates an execution carrier for the method of this application. By monitoring changes in breathing pressure within the mask body 1, voltage changes in the battery compartment 4, the operating status of the fan 6, and the pressure response within the air supply chamber 5, it is possible to complete the verification of air supply under under-voltage conditions, determine the cause of limited air supply, and handle the evacuation of air supply. Therefore, Figure 2 It can explain the actual source of the breathing pressure data, battery voltage data, fan operating status data and breathing pressure response data in this application, and can explain the physical meaning of the results of increased filter resistance, wear leakage and abnormal fan in the mining respiratory protective equipment.

[0027] In one embodiment, the method proposed in this application is applied to a supplied-air respirator worn by underground coal mine workers. Before execution, the following parameters are preset: breathing pressure sampling frequency, battery voltage sampling interval, undervoltage warning voltage, undervoltage drop rate threshold, stable amplitude threshold, stable duration threshold, response threshold, leakage duration threshold, speed feedback threshold, safe negative pressure threshold, minimum safe air supply level, and various basic air supply levels. These thresholds can be obtained through factory calibration and adjustments based on the mine's usage scenarios. Specifically, the undervoltage warning voltage is determined based on the battery discharge curve, the minimum safe air supply level, and the reserved evacuation time. The stable amplitude threshold is determined based on the breathing pressure sampling noise and the normal exhalation end-pressure fluctuation range. The response threshold is determined based on pressure response data under clean filters, normal wearing conditions, and different verified air supply levels. The leakage duration threshold is determined based on the difference in pressure drop time between a normal, tightly fitted wearing condition and an intentionally loosened wearing condition. The speed feedback threshold is determined based on the lower limit of the normal fan speed at each verified air supply level. The above thresholds can be uniform factory values ​​in the same batch of equipment, or they can be updated after the first self-test or after replacing the filter.

[0028] In one embodiment, respiratory pressure data and battery voltage data are continuously collected in S100. Respiratory pressure data refers to the pressure change data of the breathing space near the wearer's mouth and nose relative to the ambient pressure, and battery voltage data refers to the battery terminal voltage and its change over time during air delivery. When identifying respiratory cycles from the respiratory pressure data, the pressure drop segment, pressure recovery segment, and pressure stabilization segment are first determined. The pressure drop segment characterizes the inhalation process, the pressure recovery segment characterizes the pressure rise process after exhalation, and the pressure stabilization segment characterizes the end of exhalation or the respiratory pause process. If multiple respiratory cycles are continuously identified within a preset wearing observation period, and each respiratory cycle includes both a pressure drop segment and a pressure recovery segment, a wearing confirmation result of effective wearing is obtained. If no continuous respiratory cycles are identified within the preset wearing observation period, or if the respiratory pressure data remains close to the ambient pressure for an extended period, a wearing confirmation result of ineffective wearing is obtained.

[0029] In one embodiment, during S200, the inspiratory negative pressure amplitude and expiratory recovery amplitude are extracted only after the wearing confirmation result is deemed effective. The inspiratory negative pressure amplitude refers to the magnitude of pressure drop during inhalation within the same respiratory cycle. The expiratory recovery amplitude refers to the magnitude of pressure recovery to the stable pressure at the end of exhalation after inhalation. When obtaining the baseline ventilation level, the inspiratory negative pressure amplitude is used as the primary criterion for judging the wearer's inspiratory needs, and the expiratory recovery amplitude is used as a secondary criterion for judging whether the respiratory cycle is complete. When the inspiratory negative pressure amplitude is in the low-load range, a low baseline ventilation level is obtained. When the inspiratory negative pressure amplitude is in the medium-load range, a medium baseline ventilation level is obtained. When the inspiratory negative pressure amplitude is in the high-load range and the expiratory recovery amplitude reaches the effective recovery range, a high baseline ventilation level is obtained. If the expiratory recovery amplitude does not reach the effective recovery range, the baseline ventilation level is not directly increased to avoid misinterpreting loose wearing or abnormal pressure as normal enhanced inhalation.

[0030] In one embodiment, during S300, it is continuously determined whether the battery voltage data meets the undervoltage warning condition. The undervoltage warning condition includes that the battery voltage data is not higher than the undervoltage warning voltage, or that the rate of decrease of the battery voltage data is not less than the undervoltage decrease rate threshold. The rate of decrease of the battery voltage data can be determined based on the battery voltage changes at multiple consecutive sampling times. After the undervoltage warning condition is met, the air delivery level is not immediately increased based on the inspiratory negative pressure amplitude, but instead, the air delivery is rechecked during the expiratory stabilization phase. When determining the expiratory stabilization phase, the pressure stabilization segment after expiratory recovery is identified based on the respiratory pressure data. When the pressure fluctuation amplitude of the pressure stabilization segment is less than the stabilization amplitude threshold and continues to reach the stabilization duration threshold, it is determined that the expiratory stabilization phase has been entered and the air delivery recheck begins. By rechecking during the expiratory stabilization phase, the interference of the rechecked air delivery on the inspiratory process can be reduced, and the pressure response obtained during the recheck is more suitable for judging the equipment's air delivery capacity.

[0031] When determining the expiratory stabilization phase, the pressure fluctuation amplitude of the stabilization phase can be the difference between the highest and lowest pressure values ​​within the stabilization phase, or the maximum deviation of consecutive sampling points from the average pressure of the stabilization phase. A stabilization duration threshold is used to limit the shortest time for the pressure fluctuation amplitude to continuously meet the stabilization threshold, avoiding misinterpreting short-term sampling jitter as the expiratory stabilization phase. The rate of decrease in battery voltage data can be obtained by dividing the difference between the first and last sampled voltages within the preset voltage observation window by the observation window duration; when a single-point jump exists within the observation window, the jump sampling point is removed before calculating the rate of decrease in battery voltage data. The preset voltage observation window can be determined based on the battery sampling interval and the airflow level switching response time, and should be kept consistent within the same implementation.

[0032] In one embodiment, during the verification air supply, air supply is driven according to a predetermined verification air supply level, and fan operating status data and respiratory pressure response data are collected. The verification air supply level can be the current base air supply level or a fixed verification level lower than the continuous high-level air supply; the same verification air supply level is used for comparison within the same under-pressure warning process. The duration of the verification air supply is greater than the response time required for the fan to reach the verification air supply level, but shorter than a complete respiratory cycle, preferably set between 0.5 seconds and 1.5 seconds. Fan operating status data includes fan operating current and fan speed feedback, and respiratory pressure response data includes pressure increment and pressure drop duration. When processing the verification air supply data, the pressure during the expiratory stabilization phase before the verification air supply begins is used as the verification reference pressure, and the pressure increment is obtained based on the pressure increase relative to the verification reference pressure during the verification air supply period. The pressure increase can be the difference between the highest pressure value during the verification air supply period and the verification reference pressure, or the difference between the average pressure of multiple sampling points after the verification air supply stabilizes and the verification reference pressure. After the retest air delivery is completed, record the time required for the respiratory pressure to recover to the allowable range of the retest baseline pressure, thus obtaining the pressure drop duration. The allowable range of the retest baseline pressure can be determined based on the respiratory pressure sampling error and normal end-expiratory fluctuations, avoiding misjudgments of pressure drop duration due to fluctuations at a single sampling point.

[0033] Specifically, under the same verified air supply level, the air supply response is obtained based on the pressure increment, fan operating current, and fan speed feedback. The air supply response can be determined according to the correspondence between the pressure increment and the fan speed feedback, or according to the correspondence between the pressure increment and the fan operating current; in the same implementation, the calculation method for the air supply response remains consistent. Judgments regarding changes such as increased fan operating current, decreased air supply response, increased inspiratory negative pressure amplitude, and no decrease in expiratory recovery amplitude are all based on the most recent valid verification data within the same under-pressure warning process or stable operating data before the under-pressure warning. To avoid misjudgments due to sampling errors, an increase, decrease, or increase is confirmed only when the difference between the data to be judged and the comparison benchmark exceeds the corresponding change confirmation margin; if the difference does not exceed the corresponding change confirmation margin, no decrease or increase is confirmed. The change confirmation margin can be determined based on the pressure sampling accuracy, fan current sampling accuracy, speed feedback accuracy, and the normal downhole breathing fluctuation range. After replacing the filter, restarting the device, or re-establishing the wearing confirmation results, a new comparison baseline should be established.

[0034] Furthermore, the filtration resistance and leakage attenuation metrics are used to determine the cause of air supply limitation. The filtration resistance metric reflects the state where the fan operating load increases but the breathing space pressure response decreases under the same verified air supply level; when the filtration resistance metric corresponds to an increase in fan operating current and a decrease in air supply response, the result is judged as an increase in filtration resistance. The leakage attenuation metric reflects the breathing space pressure maintenance capability after the verified air supply ends; when the pressure drop time corresponding to the leakage attenuation metric is shorter than the leakage duration threshold, the result is judged as a leak. Thus, the air supply response, filtration resistance, and leakage attenuation metrics correspond to air supply capacity, filtration resistance change, and wearing seal status, respectively, avoiding the direct increase of air supply level based solely on an increase in the suction negative pressure amplitude.

[0035] In one embodiment, when executing S400, the cause of limited air supply is determined according to a preset priority order. First, it is determined whether the fan speed feedback is lower than the speed feedback threshold. If it is lower than the speed feedback threshold, a fan abnormality result is obtained. If the fan speed feedback is not lower than the speed feedback threshold, it is then determined whether the air supply response is lower than the response threshold and whether the pressure drop time is shorter than the leakage time threshold. If both conditions are met, a wearing leakage result is obtained. If the fan speed feedback is not lower than the speed feedback threshold, the fan operating current increases, the air supply response decreases, and the pressure drop time is not shorter than the leakage time threshold, an increased filter resistance result is obtained. If the fan speed feedback is not lower than the speed feedback threshold, the inhalation negative pressure amplitude increases, the air supply response does not decrease, and the exhalation recovery amplitude does not decrease, an increased workload result is obtained. Through the above priority order, it is possible to avoid the same set of verified air supply data falling into multiple judgment results simultaneously. For example, abnormal fan speed first excludes insufficient mechanical air supply capacity, excessively rapid pressure drop first points to wearing leakage, and increased current and decreased pressure response then point to increased filter resistance.

[0036] In one embodiment, during S500, the remaining air supply is determined based on battery voltage data and verified air supply data. Specifically, the evacuation descent rate threshold can be determined based on the rate of decrease in battery voltage data, the fan operating current in the verified air supply data, and the minimum safe air supply level. The minimum safe air supply level refers to the air supply level that can maintain basic breathing assistance after an undervoltage warning. The evacuation descent rate threshold can be determined by testing the battery voltage decrease under different filter resistance states at the minimum safe air supply level. When the fan operating current is within the normal current range, the evacuation descent rate threshold uses the calibrated value. The normal current range is determined based on the fan operating current under the minimum safe air supply level with the filter cleaned and in normal wearing condition. When the fan operating current is higher than the normal current range but has not reached the overcurrent protection range, the evacuation descent rate threshold is adjusted from the calibrated value to a first reduction threshold. The first reduction threshold is lower than the calibrated value, which is used to ensure that a faster battery voltage decrease is identified as a restricted air supply earlier. When the fan operating current reaches the overcurrent protection range, or when multiple consecutive verification air supply cycles show currents exceeding the normal range, the evacuation descent rate threshold is adjusted to the second reduction threshold. The second reduction threshold is lower than the first reduction threshold and is used to prioritize maintaining the minimum safe air supply time during the evacuation phase. The above calibration values, the first reduction threshold, and the second reduction threshold can be determined through factory discharge testing and recalibrated after changing battery or fan specifications. If the rate of decrease in battery voltage is less than the evacuation descent rate threshold, the evacuation air supply result is maintainable air supply. If the rate of decrease in battery voltage is not less than the evacuation descent rate threshold, the evacuation air supply result is restricted air supply.

[0037] The minimum safe airflow level refers to the airflow level used to maintain basic breathing assistance and reserve evacuation time after a low-voltage warning. The minimum safe airflow level can be determined through airflow tests under clean filter conditions, normal wearing conditions, and low-voltage battery conditions. Continuous high-level airflow refers to an airflow level exceeding the minimum safe airflow level, where the duration reaches a continuous airflow duration threshold. This threshold is determined based on the battery discharge curve and evacuation reserve time. Short-term inspiratory compensation airflow is not considered continuous high-level airflow; its duration is limited to the current inspiratory phase, and it reverts to the minimum safe airflow level after compensation.

[0038] In one embodiment, during S600, a safe air supply handling result is generated based on the air supply limitation cause determination result and the evacuation air supply result. When the evacuation air supply result indicates that air supply can be maintained, normal air supply is performed. In normal air supply, if the air supply limitation cause determination result is an increase in workload, the air supply level is allowed to be increased to meet the breathing needs of the wearer after the increase in workload. If the air supply limitation cause determination result is an increase in filter resistance, the basic air supply level is maintained and a filter maintenance warning is output to remind the wearer to maintain or replace the filter under safe conditions. If the air supply limitation cause determination result is a leak, the basic air supply level is maintained and a re-wearing warning is output. If the air supply limitation cause determination result is a fan malfunction, normal air supply is stopped and a shutdown evacuation warning is output. When the evacuation air supply result is a limited air supply, evacuation air supply is performed. Evacuation air supply uses the lowest safe air supply level as the basic air supply state, and it is prohibited to enter continuous high-level air supply based on the workload increase result to avoid shortening the available air supply time during the evacuation phase due to continuous high-load operation when the battery power is insufficient.

[0039] In one embodiment, the evacuation air supply is further processed based on the determination of the cause of air supply limitation. When the cause of air supply limitation is determined to be an increase in operating load and the suction negative pressure amplitude is greater than the safe negative pressure threshold, short-term suction compensation air supply is performed, and the minimum safe air supply is restored after the current suction phase ends. When the cause of air supply limitation is determined to be an increase in filter resistance and the suction negative pressure amplitude is greater than the safe negative pressure threshold, continuous high-level air supply is restricted and short-term suction compensation air supply is performed, and the minimum safe air supply is restored after the compensation ends. When the cause of air supply limitation is determined to be a leakage during wear, the minimum safe air supply is maintained and a re-wearing warning is issued. When the cause of air supply limitation is determined to be a fan malfunction, normal air supply is stopped and a shutdown evacuation warning is issued. The safe negative pressure threshold can be determined based on the maximum suction negative pressure acceptable to the wearer at the minimum safe air supply level. The duration of short-term suction compensation air supply does not exceed the current suction phase to avoid turning short-term compensation into continuous high-level air supply.

[0040] See Figure 3As shown, when the under-pressure warning conditions are not met, the mining respiratory protective equipment continues to supply air at the basic air supply level. When the under-pressure warning conditions are met, the system waits for the exhalation to stabilize before re-testing the air supply and collecting fan operation data and breathing pressure response data. Then, based on the re-tested air supply data, the cause of air supply limitation is determined, obtaining results for increased work load, increased filter resistance, leakage of protective gear, or fan malfunction. The remaining air supply is then assessed. If the evacuation air supply result indicates that air supply is sustainable, normal air supply is initiated. If the evacuation air supply result indicates limited air supply, continuous high-level air supply is prohibited, and evacuation air supply is initiated. During evacuation air supply, an increased work load triggers short-term inhalation compensation air supply; increased filter resistance triggers restriction of continuous high-level air supply and short-term inhalation compensation air supply; leakage of protective gear triggers minimum safe air supply and re-wearing warnings; and fan malfunction triggers a stop to normal air supply and a shutdown evacuation warning. Therefore, Figure 3 This corresponds to the undervoltage verification air supply and evacuation air supply control process in S300 to S600.

[0041] To facilitate understanding, a specific example is given below. During a certain underground tunneling face operation, the breathing pressure sampling frequency was 50Hz, the observation period was 10s, and after continuously identifying three breathing cycles including pressure drop and recovery phases, a valid wearing confirmation result was obtained. The undervoltage warning voltage was set to 3.45V, and the undervoltage drop rate threshold was set to 0.04V per minute. When the battery voltage dropped to 3.44V, the undervoltage warning condition was triggered. Subsequently, a verification air supply was performed during the stabilization phase of exhalation. The pressure fluctuation amplitude during the stabilization phase was less than 8Pa and lasted for 0.8s, meeting the stabilization phase condition. The pressure during the stabilization phase before the verification air supply began was used as the verification reference pressure. The pressure increment during the verification air supply was 18Pa, the fan operating current was 190mA, the fan speed feedback was not lower than the speed feedback threshold, and the pressure drop time after the verification air supply ended was 1.6 seconds. If the pressure increase was 25 Pa and the fan operating current was 160 mA under the same air supply level during the previous review, and the current pressure drop time is not shorter than the leakage time threshold, then it is determined to be a result of increased filter resistance. If the evacuation descent speed threshold is determined to be 0.03 V per minute based on the minimum safe air supply level and the current fan operating current, and the current battery voltage data shows a decrease speed of 0.04 V per minute, then the evacuation air supply result is limited air supply. If the current suction negative pressure amplitude is greater than the safe negative pressure threshold, then continuous high-level air supply is restricted, and short-term suction compensation air supply is only performed during the current suction phase, and the minimum safe air supply is restored after the suction phase ends.

[0042] Understandably, this embodiment does not simply reduce the airflow when the battery is low, nor does it continuously increase the airflow level due to increased inhalation negative pressure. Instead, it utilizes the airflow verification during the stabilization phase of exhalation to obtain the relationship between the fan's operating status and the breathing pressure response. This allows for separate handling of increased workload, increased filter resistance, wear leakage, and fan malfunction. This embodiment makes the airflow control during the under-pressure evacuation phase no longer rely on a single pressure change for judgment. It can actively suppress continuous high-level airflow when filter resistance increases and the battery level drops rapidly, while retaining short-term auxiliary capabilities during high inhalation loads. This balances breathing comfort, fault warning, and remaining airflow time during evacuation.

[0043] Based on another preferred embodiment described above, see [link to preferred embodiment]. Figure 4 As shown, this embodiment provides a ventilation safety early warning system for mining respiratory protective equipment, used in applying the aforementioned ventilation safety early warning method for mining respiratory protective equipment, including: The data acquisition unit is used to collect respiratory pressure data and battery voltage data, identify the respiratory cycle from the respiratory pressure data, and obtain a wearing confirmation result.

[0044] The first processing unit is used to extract the inspiratory negative pressure amplitude and expiratory recovery amplitude of the breathing pressure data when the wearing confirmation result is effective, obtain the basic air supply level, and deliver air according to the basic air supply level.

[0045] The second processing unit is used to perform a re-verification of the air supply during the stabilization phase of exhalation when the battery voltage data meets the undervoltage warning conditions, and to collect the re-verification air supply data.

[0046] The first judgment unit is used to determine the cause of air supply limitation by reviewing the air supply data, inhalation negative pressure amplitude and exhalation recovery amplitude, and to obtain the result of the air supply limitation cause determination.

[0047] The second judgment unit is used to judge the remaining air supply based on the battery voltage data and the verified air supply data, and obtain the evacuation air supply result.

[0048] The output unit is used to generate safe air supply handling results based on the determination of the cause of air supply limitation and the results of evacuation of air supply.

[0049] When the above system executes the aforementioned method, it can achieve the same technical effect as the aforementioned method.

[0050] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the protection scope of the present invention.

Claims

1. A method for early warning of ventilation safety in mining respiratory protective equipment, characterized in that, include: Collect respiratory pressure data and battery voltage data, identify the respiratory cycle from the respiratory pressure data, and obtain a wearing confirmation result; When the wearing confirmation result is effective wearing, the inspiratory negative pressure amplitude and expiratory recovery amplitude of the breathing pressure data are extracted to obtain the basic air supply level, and air is supplied according to the basic air supply level; When the battery voltage data meets the undervoltage warning condition, a verification air supply is performed during the expiratory stabilization phase, and verification air supply data is collected. The verification air supply data includes fan operating status data and respiratory pressure response data. The air supply data, inhalation negative pressure amplitude and exhalation recovery amplitude are reviewed to determine the cause of air supply limitation, and the result of the air supply limitation determination is obtained. The result of the air supply limitation determination is the result of increased workload, increased filter resistance, wear leakage or abnormal fan. Based on the battery voltage data and the verified air supply data, the remaining air supply is determined to obtain the evacuation air supply result; A safe air supply handling result is generated based on the determination result of the air supply limitation cause and the evacuation air supply result. When the evacuation air supply result is that the air supply can be maintained, normal air supply is carried out according to the determination result of the air supply limitation reason; When the evacuation air supply result is restricted air supply, continuous high-level air supply is prohibited, and evacuation air supply shall be carried out according to the determination result of the reason for the restricted air supply.

2. The method for safety early warning of air supply in mining respiratory protective equipment according to claim 1, characterized in that, The undervoltage warning conditions include: the battery voltage data is not higher than the undervoltage warning voltage, or the rate of decrease of the battery voltage data is not less than the undervoltage decrease rate threshold.

3. The method for safety early warning of air supply in mining respiratory protective equipment according to claim 1, characterized in that, Determining the expiratory stabilization phase includes: Identify the pressure stabilization segment after expiratory recovery based on the respiratory pressure data; When the pressure fluctuation amplitude of the pressure stabilization segment is less than the stabilization amplitude threshold and continues to reach the stabilization duration threshold, it is determined to be the exhalation stabilization stage and the air delivery is rechecked.

4. The method for safety early warning of air supply in mining respiratory protective equipment according to claim 1, characterized in that, Processing the aforementioned verification air supply data includes: The fan operating status data includes fan operating current and fan speed feedback, and the breathing pressure response data includes pressure increment and pressure drop time. The pressure during the stable expiratory phase before the start of the verification air supply is used as the verification reference pressure. The pressure increment is obtained based on the pressure rise relative to the verification reference pressure during the verification air supply period. The pressure drop duration is obtained based on the duration it takes for the pressure to return to the allowable range of the verification reference pressure after the verification air supply ends. Under the same verification air supply level, the air supply response is obtained based on the pressure increment, fan operating current, and fan speed feedback. The filter resistance characterization is obtained based on the increase in fan operating current and the decrease in air supply response. The leakage attenuation characterization is obtained based on the comparison between the pressure drop duration and the leakage duration threshold.

5. The method for safety early warning of air supply in mining respiratory protective equipment according to claim 4, characterized in that, When determining the cause of air supply limitation, the following should be included: If the fan speed feedback is lower than the speed feedback threshold, an abnormal fan result is obtained. If the fan speed feedback is not lower than the speed feedback threshold, the air supply response is lower than the response threshold, and the pressure drop time is shorter than the leakage time threshold, the wearing leakage result is obtained. If the fan speed feedback is not lower than the speed feedback threshold, the fan operating current increases, the air supply response decreases, and the pressure drop time is not shorter than the leakage time threshold, the result of increased filtration resistance is obtained. If the fan speed feedback is not lower than the speed feedback threshold, the inhalation negative pressure amplitude increases, the air supply response volume does not decrease, and the exhalation recovery amplitude does not decrease, the result of increased workload is obtained.

6. The method for safety early warning of air supply in mining respiratory protective equipment according to claim 5, characterized in that, When determining the remaining air supply, the following should be included: The evacuation descent speed threshold is determined based on the rate of decrease in battery voltage data, the fan operating current in the verified air supply data, and the minimum safe air supply level. When the rate of decrease of the battery voltage data is less than the evacuation rate threshold, the evacuation air supply result is that the air supply can be maintained. When the rate of decrease of the battery voltage data is not less than the evacuation rate threshold, the evacuation air supply result is restricted air supply.

7. The method for safety early warning of air supply in mining respiratory protective equipment according to claim 6, characterized in that, The general air supply includes: allowing an increase in the air supply level when the workload increases, maintaining the basic air supply level and outputting a filter maintenance warning when the filter resistance increases.

8. The method for safety early warning of air supply in mining respiratory protective equipment according to claim 7, characterized in that, The evacuation air supply includes: using the lowest safe air supply level as the basic air supply state, and prohibiting continuous high-level air supply based on the increase in work load.

9. The method for safety early warning of air supply in mining respiratory protective equipment according to claim 8, characterized in that, The evacuation air supply also includes: When the workload increases and the suction negative pressure amplitude exceeds the safe negative pressure threshold, short-term suction compensation air supply is performed. When the filter resistance increases and the suction negative pressure amplitude exceeds the safe negative pressure threshold, continuous high-speed air supply is restricted and short-term suction compensation air supply is performed. If a leak occurs while wearing the garment, maintain minimum safe airflow and issue a re-wearing warning. If the fan malfunctions, stop normal air supply and issue a shutdown and evacuation warning.

10. A ventilation safety early warning system for mining respiratory protective equipment, used to apply the ventilation safety early warning method for mining respiratory protective equipment as described in any one of claims 1-9, characterized in that, include: The acquisition unit is used to acquire respiratory pressure data and battery voltage data, identify the respiratory cycle from the respiratory pressure data, and obtain a wearing confirmation result. The first processing unit is used to extract the inspiratory negative pressure amplitude and expiratory recovery amplitude of the breathing pressure data when the wearing confirmation result is effective wearing, to obtain the basic air supply level, and to supply air according to the basic air supply level. The second processing unit is used to perform a re-verification of the air supply during the stabilization phase of the exhalation when the battery voltage data meets the undervoltage warning condition, and to collect the re-verification air supply data. The first judgment unit is used to determine the cause of air supply limitation based on the verified air supply data, inhalation negative pressure amplitude and exhalation recovery amplitude, and to obtain the result of the air supply limitation cause determination. The second judgment unit is used to judge the remaining air supply based on the battery voltage data and the verified air supply data, and obtain the evacuation air supply result. The output unit is used to generate a safe air supply handling result based on the determination result of the air supply limitation cause and the evacuation air supply result.

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