Mine return air lane self-power generation wireless multi-parameter sensor and working method thereof

Abstract

This invention discloses a self-generated wireless multi-parameter sensor for mine return airways and its operating method, addressing the problems of restricted deployment of explosion-proof equipment in return airways, difficulties in long-distance wiring, short battery life of passive devices, and poor wireless transmission stability. The core of this invention's technical solution lies in: converting wind energy in the return airway into electrical energy through a low-wind-speed adaptive impeller; after intrinsically safe rectification and voltage regulation, the electrical energy is stored by a supercapacitor and solid-state lithium battery composite energy storage system to achieve fluctuation smoothing and long-term power supply; driving intrinsically safe sensors such as differential pressure, temperature, and humidity sensors to collect data through an intermittent wake-up mechanism of an ultra-low-power main controller; and achieving self-organizing networking and low-power data upload through a LoRa wireless module. This invention is mainly used for all-weather, wire-free, passive online monitoring in confined areas such as coal mine return airways and return air corners.

Description

Technical Field

[0001] This invention relates to the technical field of intelligent monitoring in underground coal mines, and in particular to a self-generated wireless multi-parameter sensor for mine return airway and its working method. Background Technology

[0002] Coal mine return airways are the core channels for exhausting ventilation gases and are key areas for coal mine safety management, requiring comprehensive monitoring of environmental parameters across the entire roadway and section. However, current industry-standard monitoring solutions face the following long-standing unresolved on-site technical challenges: 1) The return airway is a high-risk explosion-proof control area, and the deployment of a large number of explosion-proof electrical devices is strictly prohibited. Traditional sensors and power supplies with explosion-proof enclosures cannot be densely installed in the return airway, resulting in a large number of blind spots in the monitoring coverage.

[0003] 2) The return airway is long, with complex support structures, prone to deformation, and susceptible to roof and wall collapse. Traditional intrinsically safe sensors require long-distance laying of power and communication cables, resulting in extremely high material, construction, and inspection and maintenance costs. Furthermore, roadway compression can easily cause cable damage, leakage, and breakage, posing electrical safety hazards. Simultaneously, long-distance cables suffer from severe signal attenuation and poor monitoring stability.

[0004] 3) Most existing passive wireless sensors are powered by a single battery. However, in the underground environment, batteries cannot be replaced frequently, resulting in insufficient battery life and monitoring interruption. This makes it difficult to meet the safety supervision requirements of 24-hour uninterrupted monitoring in coal mines.

[0005] 4) Ordinary WiFi, Bluetooth and other wireless modules have weak penetration and diffraction capabilities and high power consumption. They cannot adapt to the narrow, long, obstructed, and dusty tunnel environment underground. They also have high packet loss rates over long distances and insufficient network stability.

[0006] 5) Existing underground micro wind power devices are mostly designed for high wind speed scenarios in the intake airway. They have high start-up wind speeds, no dustproof and anti-clogging structures, and are not intrinsically safe. They cannot adapt to the special working conditions of low wind speed, high coal dust, and explosion-proof restrictions in the return airway. Summary of the Invention

[0007] This invention proposes a self-generated wireless multi-parameter sensor for mine return airway and its working method. It adopts an architecture of low wind speed adaptive wind energy acquisition, intrinsically safe composite energy storage, ultra-low power intermittent wake-up and LoRa wireless networking to achieve wire-free, intrinsically safe and uninterrupted environmental parameter monitoring in the return airway.

[0008] According to an embodiment of the present invention, a self-generated wireless multi-parameter sensor for mine return airway includes an intrinsically safe, dustproof, and corrosion-resistant housing, a low-wind-speed adaptive wind energy harvesting mechanism, an intrinsically safe power conversion composite energy storage system, an ultra-low-power main control and management system, a mine multi-parameter sensing unit, and a LoRa low-power roadway adaptive wireless networking transmission unit. The housing is an integrated enclosed structure, and a wall-mounted quick-installation structure is fixed to the outer wall of the housing. The low-wind-speed adaptive wind energy harvesting mechanism includes a seven-bladed arc-shaped thin-walled lift impeller, an integrated arc-shaped flow guide dust cover, a omnidirectional adaptive base, and a miniature permanent magnet brushless generator. The impeller is mounted on the rotor shaft of the generator. The dust cover is installed outside the impeller and fixedly connected to the base. The base is installed outside the housing to allow the impeller to passively rotate under the action of wind flow to face the mainstream wind direction. The intrinsically safe power conversion composite energy storage system includes a rectifier. The voltage regulator circuit, supercapacitor, and intrinsically safe solid-state lithium battery are all housed inside the casing. The input terminal of the rectifier and voltage regulator circuit is electrically connected to the output terminal of the generator, and the output terminal of the rectifier and voltage regulator circuit is electrically connected to the supercapacitor and the intrinsically safe solid-state lithium battery, respectively. The ultra-low power main control management system includes an industrial-grade ultra-low power MCU, housed inside the casing. The power supply terminal of the MCU is electrically connected to the output terminal of the intrinsically safe power conversion composite energy storage system. The mining multi-parameter sensing unit includes at least one of differential pressure, temperature and humidity, and absolute pressure monitoring modules, housed inside or on the casing. The signal output terminal of the sensing unit is electrically connected to the signal input terminal of the MCU. The LoRa low-power tunnel adaptive wireless networking transmission unit includes a LoRa RF module and an antenna, housed inside the casing. The LoRa RF module is bidirectionally electrically connected to the MCU, and the antenna is electrically connected to the output terminal of the LoRa RF module.

[0009] According to one embodiment of the present invention, in the low wind speed adaptive wind energy harvesting mechanism, the impeller adopts a large curvature and low wind resistance airfoil structure; the dust cover has a forward-inclined guide slope, and there is a gap between the inner wall of the dust cover and the outer edge of the impeller. When the airflow passes through, a directional blowing airflow is formed to automatically blow the impeller surface and the impeller gap; the base is a passive mechanical structure, including a vertical rotating shaft, a horizontal rotating shaft and a tail rudder plate. The vertical rotating shaft is installed outside the housing, the horizontal rotating shaft connects the vertical rotating shaft and the impeller, and the tail rudder plate is fixed to the rear of the impeller.

[0010] According to one embodiment of the present invention, in an intrinsically safe power conversion composite energy storage system, the rectifier and voltage regulator circuit is a current-limiting and voltage-limiting circuit; the supercapacitor is connected in parallel with the intrinsically safe solid-state lithium battery, and the charging and discharging response speed of the supercapacitor is faster than that of the intrinsically safe solid-state lithium battery; the system also integrates an overcharge protection circuit, an over-discharge protection circuit, an overcurrent protection circuit, a short-circuit protection circuit, a temperature protection circuit, and a reverse current-feeding protection circuit, and the detection terminal of each protection circuit is electrically connected to the corresponding protected device.

[0011] According to one embodiment of the present invention, in the ultra-low power main control management system, the MCU has a built-in multi-level sleep wake-up and dynamic power consumption adjustment mode, which is used to automatically switch between three modes: deep sleep, standby monitoring, and working acquisition, according to the energy storage capacity, and adaptively adjust the acquisition and reporting frequency according to the power generation. In the deep sleep mode, the static power consumption of the whole machine is at an extremely low level, and only the voltage detection unit inside the MCU remains working. In the standby monitoring mode, the MCU waits for the wake-up signal. In the working acquisition mode, the MCU drives the sensing unit and the LoRa radio frequency module to complete the acquisition and transmission.

[0012] According to one embodiment of the present invention, each sensor in the sensing unit is provided with a power switch circuit. The control terminal of the power switch circuit is electrically connected to the I / O port of the MCU, which is used to power on and collect data at the moment of operation and to power off immediately after the data collection is completed. The MCU has a built-in digital filtering module, an outlier rejection module and a temperature compensation module, which are used to process the collected data and package it for transmission.

[0013] According to one embodiment of the present invention, in the transmission unit, the LoRa radio frequency module is equipped with an ultra-low sleep mode, a strong diffraction penetration mode, and an adaptive frequency hopping mode, which enables long-distance reliable transmission in underground coal mine roadways; the MCU is equipped with a power consumption linkage transmission mode: when the energy storage is sufficient, the LoRa radio frequency module is controlled to upload data in real time, and when the energy storage is low, the LoRa radio frequency module is controlled to adopt a batch packet delayed upload mode.

[0014] According to one embodiment of the present invention, the housing is integrally formed from corrosion-resistant and flame-retardant engineering materials and has a dustproof and waterproof protection rating; the wall-mounted quick-installation structure includes a self-locking fixing buckle, which is fixedly connected to the back of the housing.

[0015] This invention also provides a method for operating a sensor, comprising the following steps: S1: The airflow in the return airway drives the impeller to rotate, and the generator converts wind energy into low-voltage electrical energy; S2: After being processed by a rectifier and voltage regulator circuit, the low-voltage electrical energy is stored in a composite energy storage system consisting of a supercapacitor and an intrinsically safe solid-state lithium battery; S3: The MCU monitors the energy storage status in real time and intelligently wakes up based on the power threshold; S4: The sensing unit intermittently collects differential pressure, absolute pressure, temperature, and humidity parameters, which are then calibrated by the MCU; S5: The LoRa radio frequency module completes data packaging and self-organizing networking, and uploads the data to the downhole monitoring substation via an antenna; S6: After the data is uploaded, the MCU controls the entire unit to immediately enter deep sleep mode, repeating the cycle; S7: Under conditions of wind stoppage or extremely low wind speed, the composite energy storage system provides backup power to ensure the equipment remains online.

[0016] The beneficial effects of this invention are that it addresses several technical bottlenecks in coal mine return airway monitoring scenarios. Through a novel structural design, intrinsically safe energy storage method, ultra-low power consumption control, and LoRa wireless networking architecture, compared to existing technologies, the specific technical effects are as follows: 1. This invention abandons the explosion-proof housing and explosion-proof power supply architecture of traditional sensors and adopts a pure intrinsically safe electrical design. The whole machine has no explosion-proof components, no high-voltage energy storage unit, and no risk of explosion failure. It fully meets the equipment deployment requirements for high-risk areas such as return airway and return air corner. For the first time, it realizes safe, legal and dense deployment monitoring of the entire section of the return airway and blind spots at the corners, filling the technical gap in the industry. 2. This invention adopts a wind-powered self-powered and fully wireless LoRa transmission architecture, completely eliminating long-distance power and communication cables. This fundamentally solves the safety hazards of cable damage, leakage, wire breakage, and electric sparks caused by deformation of the return airway and roof collapse squeezing the cables. At the same time, it saves the high costs of cable procurement, roadway hanging, manual laying, and daily inspection and maintenance, significantly reducing the construction and operation and maintenance costs of the ventilation and fire prevention monitoring system. The equipment installation does not require roadway construction and has no construction safety risks. 3. Through the use of low-wind-speed airfoil impellers, universal adaptive windward mechanism and self-cleaning dustproof and airflow guiding structure, the equipment can start generating electricity at ultra-low wind speeds of 0.7 m / s, adapting to the flow field characteristics of low wind speed, large wind speed fluctuations and turbulent wind direction in return airway; the airflow self-purification structure eliminates the problem of coal dust accumulation and blockage, realizing long-term maintenance-free and stable wind energy collection in harsh underground high-dust environments; 4. It adopts a composite energy storage architecture of supercapacitor and solid-state intrinsically safe lithium battery, combined with full-link intrinsically safe protection circuit and intelligent energy consumption management strategy; the supercapacitor quickly smooths the power fluctuation of wind power generation, and the lithium battery is responsible for long-term power supply, realizing stable voltage output in windy conditions, frequency reduction to ensure online operation in low wind speed conditions, and ultra-long endurance of more than 20 days in wind stop maintenance conditions, meeting the 24 hours × 365 days uninterrupted safety monitoring requirements of coal mines; 5. Compared with traditional wireless technologies such as WiFi and Bluetooth, this invention adopts LoRa mining-specific low-power networking technology, which has stronger diffraction, penetration and anti-dust attenuation capabilities in tunnels. It significantly reduces packet loss rate and extends transmission distance in environments with multiple steel frame obstructions and narrow tunnels. At the same time, it achieves precise matching between wireless transmission power consumption and self-powered system, supports automatic networking of multiple nodes and gateway-free access to existing coal mine monitoring systems. 6. Through multi-level sleep and wake-up methods and a linkage adjustment algorithm between power generation and acquisition frequency, dynamic adaptive balance between power generation, energy storage capacity and equipment power consumption is achieved; when energy storage is sufficient, the monitoring frequency and accuracy are increased, and when energy storage is insufficient, ineffective power consumption is reduced and the equipment is kept connected to the network, truly realizing passive, wireless, maintenance-free and routine intelligent monitoring. 7. The whole machine has an IP65 dustproof, corrosion-proof and waterproof rating, which is suitable for the harsh environment of dampness, corrosion and high dust in underground mines; it adopts a drilling-free wall-mounted quick installation structure, which can be flexibly deployed in blind spots such as roadway sides, roof, and return air corners that traditional equipment cannot cover. It is suitable for intelligent technology transformation scenarios of return air roadways in new and old mines, and has strong engineering implementation and versatility. Attached Figure Description

[0017] Figure 1 This is a functional architecture diagram of the mine return airway self-generated wireless multi-parameter sensor of the present invention; Figure 2 This is a flowchart of the working method of the self-generated wireless multi-parameter sensor for mine return airway according to the present invention. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] The following describes in detail, with reference to the accompanying drawings, an embodiment of the present invention: a self-generating wireless multi-parameter sensor for mine return airway and its working method.

[0020] See Figure 1 This invention provides a self-generated wireless multi-parameter sensor for mine return airways, comprising an intrinsically safe, dustproof, and corrosion-resistant housing, a low-wind-speed adaptive wind energy acquisition mechanism, an intrinsically safe power conversion and storage system, an ultra-low-power main control and management system, a mine-use multi-parameter sensing unit, and a LoRa low-power tunnel adaptive wireless networking transmission unit. The invention employs a fully passive closed-loop architecture integrating mechanical energy micro-wind acquisition, intrinsically safe voltage-stabilized energy storage, ultra-low-power intelligent main control, multi-parameter sensing acquisition, and LoRa tunnel self-organizing network transmission. The overall design consists of six parts: a low-wind-speed adaptive wind energy acquisition mechanism, an intrinsically safe power conversion and storage system, an ultra-low-power main control and management system, a mine-use multi-parameter sensing unit, a LoRa low-power tunnel adaptive wireless networking transmission unit, and an intrinsically safe, dustproof, and corrosion-resistant housing. The overall working logic is as follows: the continuous airflow in the return airway drives a micro low-speed impeller to generate electricity. After being regulated and rectified by an intrinsically safe power management circuit, the electricity is stored in a supercapacitor and intrinsically safe battery composite energy storage unit. The main control module adopts an ultra-low power consumption strategy of intermittent wake-up and time-sharing acquisition to drive sensors to collect environmental parameters. Finally, the data is uploaded to the underground monitoring substation through a self-organizing network of LoRa low-power wireless modules, realizing passive, wireless, and wire-free continuous monitoring.

[0021] The intrinsically safe, dustproof, and corrosion-resistant housing is a one-piece enclosed structure with a wall-mounted quick-installation mechanism fixed to its outer wall. The housing is integrally molded from corrosion-resistant and flame-retardant engineering materials, offering dustproof and waterproof protection, preferably IP65, effectively resisting the corrosive effects of damp, corrosive gases, and high-dust environments in underground mines on internal electrical components. The wall-mounted quick-installation mechanism includes self-locking clips fixed to the back of the housing. During installation, simply attach the housing to a pre-designed mounting surface on the sidewall, roof, or return air corner of the tunnel using the self-locking clips; no drilling, pre-embedded fasteners, or cable laying are required for rapid installation. All electrical components of the sensor are intrinsically safe, with voltage, current, and power parameters limited to mining intrinsically safe thresholds. The entire unit has no explosion-proof cavity or explosion-proof joint surface, fully complying with safety regulations for equipment deployment in high-risk areas of coal mine return airways.

[0022] The low-wind-speed adaptive wind energy harvesting mechanism includes a seven-bladed, arc-shaped, thin-walled, lift-type impeller, an integrated arc-shaped dust cover with airflow guides, a omnidirectional, adaptive base, and a miniature permanent magnet brushless generator. The impeller employs seven arc-shaped, thin-walled, lift-type blades with a high-curvature, low-drag airfoil structure. By optimizing the blade aspect ratio and angle of attack, the impeller achieves extremely low starting wind speeds. Preferably, the impeller diameter is 120mm–200mm, the blade aspect ratio is 4–6, and the blade angle of attack is 10°–20°. In this invention, the impeller can stably start generating electricity across the entire wind speed range of 0.7m / s to 6m / s, adapting to the normal wind flow environment of 1.0m / s to 3.5m / s in coal mine return airways. The impeller is mounted on the rotor shaft of the miniature permanent magnet brushless generator; when the impeller rotates, it drives the generator rotor to rotate, converting wind energy into electrical energy. Preferably, the rated power of the micro permanent magnet brushless generator is 0.5W to 3W, the rated output voltage is 5V to 12V, the brushless structure has no mechanical wear and no electrical sparks, and meets the intrinsically safe and explosion-proof requirements.

[0023] The dust cover is an integrated arc-shaped flow guide structure, installed outside the impeller and fixedly connected to the base. The dust cover has a forward-inclined flow guide slope, and there is a gap between the inner wall of the dust cover and the outer edge of the impeller, preferably 2mm to 5mm. When airflow passes through the dust cover, it forms a directional blowing airflow under the guidance of the forward-inclined flow guide slope, automatically blowing away the impeller surface and impeller gaps to prevent impeller jamming and power generation failure caused by coal dust accumulation and adhesion. Preferably, the axial angle between the forward-inclined flow guide slope of the dust cover and the impeller axis is 15° to 30°.

[0024] The base is a passive mechanical structure with omnidirectional rotation and self-adaptation, installed outside the housing. The base includes a vertical shaft, a horizontal shaft, and a tail rudder. The vertical shaft, installed outside the housing, allows the base to rotate freely in the vertical direction; the horizontal shaft connects the vertical shaft to the impeller, allowing the impeller to oscillate within a certain angle in the horizontal direction; the tail rudder is fixed to the rear of the impeller. When the airflow direction changes, the tail rudder generates a yaw torque under wind pressure, driving the impeller and dust cover to passively rotate around the vertical shaft, ensuring the impeller always faces the prevailing wind direction. In this invention, the omnidirectional adaptive base can automatically adjust its horizontal angle of attack according to turbulent flow and turning airflow in the tunnel. The horizontal shaft allows the impeller to oscillate slightly in the vertical direction to adapt to changes in the upward or downward angle of the airflow within the tunnel. Thus, the base achieves adaptive wind response under turbulent conditions, effectively improving wind energy utilization efficiency.

[0025] The intrinsically safe power conversion and energy storage system includes a rectifier and voltage regulator circuit, a supercapacitor, and an intrinsically safe solid-state lithium battery, all housed within the casing. The rectifier and voltage regulator circuit is a current-limiting and voltage-limiting circuit, with its input terminal electrically connected to the output terminal of a micro permanent magnet brushless generator. The pulsating AC power output from the generator first enters the rectifier and voltage regulator circuit, where it is rectified, filtered, and regulated before being converted into stable low-voltage DC power. The rectifier and voltage regulator circuit limits current and voltage throughout its operation, ensuring all electrical parameters are controlled within the intrinsically safe threshold for mining applications.

[0026] The supercapacitor and intrinsically safe solid-state lithium battery are connected in parallel, with the supercapacitor exhibiting a faster charge and discharge response than the intrinsically safe solid-state lithium battery. The energy storage system employs a dynamic complementary operating mode: under windy conditions, the generator's output power, after rectification and voltage regulation, prioritizes charging the supercapacitor. The supercapacitor utilizes its rapid charge and discharge characteristics to instantly store and replenish energy, quickly responding to wind speed fluctuations, smoothing out fluctuations in power generation, and ensuring a continuous and stable downstream power supply voltage. When the supercapacitor reaches saturation, excess energy automatically charges the intrinsically safe solid-state lithium battery. Under extremely low wind speeds or short-term wind stoppages, the supercapacitor discharges first, ensuring instantaneous power acquisition and transmission for the equipment. When the supercapacitor is depleted, the intrinsically safe solid-state lithium battery serves as a backup power source, continuously supplying power to the entire system. Preferably, the supercapacitor has a capacity of 10F to 100F, and the intrinsically safe solid-state lithium battery has a capacity of 1000mAh to 5000mAh. In this invention, the intrinsically safe solid-state lithium battery can achieve continuous standby monitoring for more than 20 days in windless conditions, fully covering the monthly maintenance and ventilation shutdown cycle of coal mines.

[0027] The system also integrates overcharge protection circuits, over-discharge protection circuits, overcurrent protection circuits, short-circuit protection circuits, temperature protection circuits, and reverse current sinking protection circuits, forming a full-link safety protection module. The detection terminals of each protection circuit are electrically connected to the corresponding protected device. When any parameter exceeds the limit, the corresponding protection circuit immediately latches off the power, ensuring that the entire unit is always in an intrinsically safe operating state from a hardware perspective.

[0028] The ultra-low power main control management system includes an industrial-grade ultra-low power MCU housed inside the casing. The MCU's power supply terminal is electrically connected to the output terminal of the intrinsically safe energy conversion and storage system. The MCU incorporates multi-level sleep / wake-up and dynamic power consumption adjustment modes, which automatically switch between three modes—deep sleep, standby monitoring, and active data acquisition—based on the stored energy level, and adaptively adjust the data acquisition and reporting frequency according to the power generation.

[0029] Specifically, in deep sleep mode, the overall static power consumption is at an extremely low level, with only the voltage detection unit inside the MCU remaining operational to monitor the energy storage voltage in real time. In this mode, peripheral circuits such as the sensing unit and LoRa RF module are all powered off, reducing the overall power consumption to the microampere level. The device is normally in this deep sleep mode. In standby monitoring mode, the MCU is in a low-power waiting state, and all peripheral circuits remain powered off, maintaining only necessary clock and interrupt detection functions. When the voltage detection unit detects that the energy storage capacity has reached a preset acquisition threshold, the MCU is awakened and enters the working acquisition mode. In working acquisition mode, the MCU drives the sensing unit and LoRa RF module to power on and complete sensor data acquisition, data processing, and wireless transmission tasks. After data transmission is complete, the MCU immediately controls the device to return to deep sleep mode, eliminating unnecessary power consumption.

[0030] The dynamic power consumption adjustment method is as follows: when the stored energy is higher than a preset high threshold, the MCU automatically increases the data acquisition and reporting frequency; when the stored energy is lower than a preset low threshold, the MCU automatically decreases the acquisition frequency and extends the sleep time to prioritize ensuring the device remains online. This achieves intelligent energy consumption adaptive matching for passive devices. Preferably, the data acquisition and reporting frequency is dynamically adjusted between 5 minutes / time and 2 hours / time.

[0031] The mining multi-parameter sensing unit includes at least one of a differential pressure monitoring module, a temperature and humidity monitoring module, and an absolute pressure monitoring module, housed inside or on the housing. The signal output terminal of the sensing unit is electrically connected to the signal input terminal of the MCU. The differential pressure monitoring module measures the ventilation differential pressure in the return airway, the temperature and humidity monitoring module measures the ambient temperature and relative humidity, and the absolute pressure monitoring module measures atmospheric pressure. All sensors adopt an intrinsically safe, low-power design suitable for mining, meeting the safety requirements for use in underground coal mines. Preferably, the differential pressure monitoring module has a measurement range of -5kPa to +5kPa and an accuracy of ±0.5%FS; the temperature and humidity monitoring module has a temperature measurement range of -20℃ to +80℃ and an accuracy of ±0.5℃, a humidity measurement range of 0 to 100%RH and an accuracy of ±3%RH; and the absolute pressure monitoring module has a measurement range of 80kPa to 120kPa and an accuracy of ±0.5%FS.

[0032] Each sensor is equipped with a power switch circuit, the control terminal of which is electrically connected to the MCU's I / O port. During non-operating periods, each sensor is completely powered off and in sleep mode, consuming no power. When the MCU enters the data acquisition mode, it controls the power switch circuit to turn on via the I / O port, momentarily powering on each sensor and completing data acquisition. After acquisition, the MCU immediately controls the power switch circuit to turn off, completely de-powering the sensors. This intermittent trigger acquisition mechanism significantly reduces the average power consumption of the entire device. The acquired raw data is filtered by the MCU's built-in digital filtering module to remove noise interference, and an outlier removal module removes abnormal data caused by occasional sensor malfunctions or external interference. Finally, a temperature compensation module corrects for temperature drift before generating valid monitoring data, which is then packaged and ready for transmission.

[0033] The transmission unit of the LoRa low-power adaptive wireless networking system for underground mine tunnels includes a LoRa RF module and an antenna, housed within a casing. The LoRa RF module is bidirectionally electrically connected to the MCU, and the antenna is electrically connected to the output of the LoRa RF module. This invention employs LoRa mining-specific low-power wireless networking technology. The LoRa RF module features an ultra-low sleep mode, a strong diffraction penetration mode, and an adaptive frequency hopping mode. In ultra-low sleep mode, the power consumption of the LoRa RF module is reduced to the microampere level, only requiring a brief wake-up under MCU control to complete data transmission. In strong diffraction penetration mode, the LoRa RF module uses a low spreading factor and low bandwidth configuration to enhance the diffraction and penetration capabilities of the signal in tunnel environments with obstructions. In adaptive frequency hopping mode, the LoRa RF module automatically switches its operating frequency based on channel quality to avoid interference bands and ensure communication reliability. In underground coal mine tunnels, the LoRa RF module has long-distance reliable transmission capabilities. Preferably, in a typical coal mine tunnel environment (12m² cross-section, steel support, dust concentration 50mg / m³), the reliable transmission distance can reach over 300m.

[0034] The MCU features a power consumption-linked transmission mode: when energy storage is sufficient, the MCU controls the LoRa RF module to upload data in real time after each data acquisition; when energy storage is low, the MCU controls the LoRa RF module to store multiple data acquisitions locally, then batch package and delay the upload to reduce the number of wireless transmissions and lower power consumption. After the device is powered on, the LoRa RF module automatically scans for nearby monitoring nodes on the same network segment and underground monitoring substations, autonomously completing network access, network formation, and clock synchronization without manual configuration or separate gateway setup, and can directly connect to mainstream coal mine monitoring systems such as KJ950 and KJ95x.

[0035] See Figure 2 The present invention also provides a method for operating the above-mentioned sensor, comprising the following steps: S1: The airflow in the return airway drives the impeller to rotate, and the miniature permanent magnet brushless generator converts wind energy into low-voltage electrical energy. Specifically, the continuous airflow in the return airway acts on a seven-bladed arc-shaped thin-walled lift impeller. Preferably, the wind speed range is 0.7m / s to 6m / s. Under the action of lift, the impeller begins to rotate and drives the generator rotor to rotate. The generator converts mechanical energy into low-voltage pulsating AC electrical energy.

[0036] S2: Low-voltage electrical energy is processed by a rectifier and voltage regulator circuit and then stored in a composite energy storage system consisting of a supercapacitor and an intrinsically safe solid-state lithium battery. Specifically, the pulsating AC power output from the generator is rectified, filtered, and regulated by the rectifier and voltage regulator circuit to convert it into stable low-voltage DC power. Under windy conditions, the supercapacitor is charged first, and excess electrical energy is charged to the intrinsically safe solid-state lithium battery. Under windless or low-wind-speed conditions, the composite energy storage system supplies power to the downstream circuit.

[0037] S3: The MCU monitors the energy storage status in real time and intelligently wakes up based on the power threshold. Specifically, the voltage detection unit inside the MCU continuously monitors the energy storage voltage; when the energy storage voltage reaches the preset high wake-up threshold, the MCU switches from deep sleep mode to working acquisition mode; when the energy storage voltage is lower than the preset low sleep threshold, the MCU maintains or switches to deep sleep mode.

[0038] S4: The sensing unit intermittently collects differential pressure, absolute pressure, temperature, and humidity parameters, which are then calibrated by the MCU. Specifically, the MCU controls the power switch circuit to turn on, instantly powering on each sensor; after the sensor completes data acquisition, the MCU controls the power switch circuit to turn off, immediately de-energizing the sensor; the collected raw data is processed by the MCU's built-in digital filtering, outlier removal, and temperature compensation algorithms to generate valid monitoring data.

[0039] S5: The LoRa RF module completes data packaging, self-organizing the network, and uploading it to the downhole monitoring substation via the antenna. Specifically, the MCU packages the calibrated monitoring data according to a predetermined protocol format and sends it to the LoRa RF module via the SPI interface; the LoRa RF module performs spread spectrum modulation on the data and transmits it via the antenna; during the data upload process, the LoRa RF module automatically selects the optimal frequency and transmission power based on the channel quality.

[0040] S6: After data upload, the MCU immediately puts the entire device into deep sleep mode, repeating this cycle. Specifically, after confirming successful data upload, the MCU immediately powers off the sensing unit and LoRa RF module, switches itself to deep sleep mode, and only keeps the voltage detection unit working, waiting for the next wake-up cycle.

[0041] S7: In the event of wind stoppage or extremely low wind speed, the composite energy storage system provides backup power to ensure the equipment remains online. Specifically, when the return airway is shut down due to maintenance or other reasons, or when the wind speed remains below the impeller startup speed, the micro permanent magnet brushless generator stops generating electricity; the supercapacitor prioritizes releasing the stored electrical energy to maintain short-term operation of the equipment; when the supercapacitor is depleted, the intrinsically safe solid-state lithium battery automatically takes over power supply, ensuring continuous standby monitoring of the equipment in windless conditions.

[0042] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A self-generated wireless multi-parameter sensor for mine return airway, characterized in that, include: The intrinsically safe, dustproof, and corrosion-resistant housing is an integrated, enclosed structure, and the outer wall of the housing is fixed with a wall-mounted, quick-installation structure. A low-wind-speed adaptive wind energy harvesting mechanism includes a seven-bladed, arc-shaped, thin-walled, lift-type impeller, an integrated arc-shaped dust cover, a omnidirectional, adaptive base, and a miniature permanent magnet brushless generator. The impeller is mounted on the rotor shaft of the generator. The dust cover is placed over the impeller and fixedly connected to the base. The base is installed outside the housing to allow the impeller to passively rotate under the influence of wind flow to face the mainstream wind direction. The intrinsically safe power conversion and energy storage system includes a rectifier and voltage regulator circuit, a supercapacitor, and an intrinsically safe solid-state lithium battery, all housed inside the casing. The input terminal of the rectifier and voltage regulator circuit is electrically connected to the output terminal of the generator, and the output terminal of the rectifier and voltage regulator circuit is electrically connected to the supercapacitor and the intrinsically safe solid-state lithium battery, respectively. The ultra-low power main control management system includes an industrial-grade ultra-low power MCU, which is housed inside the housing; the power supply terminal of the MCU is electrically connected to the output terminal of the intrinsically safe power conversion composite energy storage system. A multi-parameter sensing unit for mining applications includes at least one of differential pressure, temperature and humidity, and absolute pressure monitoring modules, which is disposed inside or on the housing; the signal output terminal of the sensing unit is electrically connected to the signal input terminal of the MCU. The transmission unit for LoRa low-power lane adaptive wireless networking includes a LoRa radio frequency module and an antenna, which are disposed inside the housing. The LoRa RF module is bidirectionally electrically connected to the MCU, and the antenna is electrically connected to the output terminal of the LoRa RF module.

2. The sensor according to claim 1, characterized in that, In the low-wind-speed adaptive wind energy harvesting mechanism, the impeller adopts a large-curvature, low-drag airfoil structure; the dust cover has a forward-inclined guide slope, and there is a gap between the inner wall of the dust cover and the outer edge of the impeller, so that when the airflow passes through, a directional blowing airflow is formed to automatically blow the impeller surface and the impeller gap; the base is a passive mechanical structure, including a vertical rotating shaft, a horizontal rotating shaft and a tail rudder plate, the vertical rotating shaft is installed outside the housing, the horizontal rotating shaft connects the vertical rotating shaft and the impeller, and the tail rudder plate is fixed to the rear of the impeller.

3. The sensor according to claim 1, characterized in that, In the intrinsically safe power conversion composite energy storage system, the rectifier and voltage regulator circuit is a current-limiting and voltage-limiting circuit; the supercapacitor is connected in parallel with the intrinsically safe solid-state lithium battery, and the charging and discharging response speed of the supercapacitor is faster than that of the intrinsically safe solid-state lithium battery; the system also integrates overcharge protection circuit, over-discharge protection circuit, overcurrent protection circuit, short circuit protection circuit, temperature protection circuit and reverse current charging protection circuit, and the detection terminal of each protection circuit is electrically connected to the corresponding protected device.

4. The sensor according to claim 1, characterized in that, In the ultra-low power main control management system, the MCU has a built-in multi-level sleep / wake-up and dynamic power consumption adjustment mode, which is used to automatically switch between three modes: deep sleep, standby monitoring, and working acquisition, according to the energy storage capacity, and adaptively adjust the acquisition and reporting frequency according to the power generation. In the deep sleep mode, the static power consumption of the whole machine is at an extremely low level, and only the voltage detection unit inside the MCU remains active. In the standby monitoring mode, the MCU waits for a wake-up signal. In the working acquisition mode, the MCU drives the sensing unit and the LoRa radio frequency module to complete the acquisition and transmission.

5. The sensor according to claim 1, characterized in that, Each sensor in the sensing unit is equipped with a power switch circuit. The control terminal of the power switch circuit is electrically connected to the I / O port of the MCU, which is used to power on and collect data at the moment of operation and to power off immediately after the data collection is completed. The MCU has a built-in digital filtering module, an outlier removal module, and a temperature compensation module, which are used to process the collected data and package it for transmission.

6. The sensor according to claim 1, characterized in that, In the transmission unit, the LoRa RF module is equipped with an ultra-low sleep mode, a strong diffraction penetration mode, and an adaptive frequency hopping mode, providing reliable long-distance transmission capability in underground coal mine roadways. The MCU is equipped with a power consumption-linked transmission mode: when the energy storage is sufficient, it controls the LoRa RF module to upload data in real time; when the energy storage is low, it controls the LoRa RF module to adopt a batch packet delayed upload mode.

7. The sensor according to claim 1, characterized in that, The housing is integrally molded from corrosion-resistant and flame-retardant engineering materials and has a dustproof and waterproof protection rating; the wall-mounted quick-installation structure includes a self-locking fixing buckle, which is fixedly connected to the back of the housing.

8. The method of operating the sensor according to any one of claims 1 to 7, characterized in that, Includes the following steps: S1: The airflow in the return airway drives the impeller to rotate, and the generator converts wind energy into low-voltage electrical energy; S2: The low-voltage electrical energy is processed by the rectifier and voltage regulator circuit and then stored in the composite energy storage system composed of the supercapacitor and the intrinsically safe solid-state lithium battery. S3: The MCU monitors the energy storage status in real time and intelligently wakes up based on the power threshold; S4: The sensing unit intermittently collects differential pressure, absolute pressure, temperature and humidity parameters, which are then calibrated by the MCU; S5: The LoRa radio frequency module completes data packaging and self-organizing network, and uploads it to the downhole monitoring substation through the antenna; S6: After the data is uploaded, the MCU controls the entire machine to immediately enter deep sleep mode, and repeats this cycle. S7: Under conditions of wind stoppage or extremely low wind speed, the backup power supply equipment of the composite energy storage system remains online.

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