A lighting system and method for use in an explosive environment

Abstract

The application provides a lighting system and method for an explosive environment, and belongs to the field of mine lighting. The application solves the problems of high risk coefficient of the power supply mode of the existing lighting scheme, heat accumulation in the lighting area, and brightness attenuation in long-distance transmission. The lighting system for the explosive environment comprises a ground light source coupling regulation and control unit, an RGB laser light source module for outputting RGB laser, and a coupling structure for coupling and outputting the RGB laser; a fiber sensing unit connected to the ground light source coupling regulation and control unit at one end and connected to an underground lighting output unit in the explosive environment at the other end, used for forward transmission of the coupled laser to the underground lighting output unit and reverse transmission of monitoring data of the use state of the fiber and underground safety hazards; and the underground lighting output unit is provided with an output structure for diffusing and outputting the coupled laser to form white light for lighting. The application is mainly used for underground lighting.

Description

Technical Field

[0001] This invention belongs to the field of mining lighting, and in particular relates to a lighting system and method for use in explosive environments. Background Technology

[0002] The safety and efficiency of downhole operations depend on reliable lighting and real-time safety monitoring. Existing downhole lighting systems mostly use LEDs and incandescent lamps with conventional fiber optic transmission, which can only provide basic lighting functions and suffer from problems such as brightness attenuation and significant color shift after long-distance transmission, lacking a targeted calibration mechanism. At the same time, downhole safety monitoring relies on independently deployed sensor cables and equipment, which are isolated from the lighting system, forming data silos. It is impossible to dynamically optimize lighting parameters through monitoring data, nor can the lighting system provide feedback on equipment operation and environmental safety status, resulting in extremely poor coordination.

[0003] On the other hand, existing optical fibers only undertake single light guiding or sensing tasks, requiring separate laying of lighting optical fibers and sensing optical cables. This not only increases the cost of underground installation and occupies limited tunnel space, but also makes ordinary optical fibers insufficient in terms of wear resistance, tensile strength, and explosion-proof performance, easily damaged in the complex underground installation environment, leading to lighting interruptions or monitoring failures. In addition, existing technologies only provide local explosion-proof design for single devices. When risks such as excessive underground gas concentration occur, the lighting system cannot be automatically linked and adjusted, posing a significant safety hazard. Furthermore, when faults such as fiber breakage occur, the lighting system is directly interrupted, lacking emergency backup light sources and accurate fault location functions, delaying rescue and maintenance efficiency. Summary of the Invention

[0004] In view of this, the present invention aims to propose a lighting system and method for use in explosive environments, in order to solve the problems of high risk factor of existing lighting solutions in power supply, easy heat accumulation in the lighting area and brightness attenuation over long distances.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: According to a first aspect of the present invention, a lighting system for explosive environments is provided, comprising: The ground light source coupling and control unit is located in a safe area on the ground. It contains an RGB laser light source module for outputting RGB laser and a coupling structure for coupling and outputting the RGB laser. The fiber optic sensing unit is connected at one end to the ground light source coupling and control unit and at the other end to the underground lighting output unit located in an explosive environment. It is used to transmit the coupled laser to the underground lighting output unit in the forward direction and transmit monitoring data on the fiber optic usage status and underground safety hazards in the reverse direction. The downhole lighting output unit is equipped with a light-emitting structure for diffusing and outputting coupled laser light to form white light for illumination.

[0006] Furthermore, the system also includes a safety monitoring unit and a linkage control unit. The safety monitoring unit includes a global monitoring module and a local monitoring module. The global monitoring module is coupled to the fiber optic sensing unit to monitor the fiber optic usage status, and the local monitoring module is coupled to the downhole lighting output unit to monitor downhole safety hazard signals. Both the global monitoring module and the local monitoring module transmit the monitoring data to the linkage control unit.

[0007] Furthermore, the local monitoring module is equipped with a miniature laser dust sensor, which is used to collect local dust concentration data in the well in real time and feed it back to the linkage control unit through an optical fiber sensing unit.

[0008] Furthermore, the RGB laser source module is a red, green, and blue semiconductor laser. The coupling structure is provided with a PLC optical waveguide combiner for combining the red, green, and blue lasers into a single beam and an end-face alignment coupler for connecting the combined RGB laser to the fiber end face of the fiber optic sensing unit. The end-face alignment coupler integrates a collimating lens, a focusing lens, and a three-dimensional alignment adjustment structure.

[0009] Furthermore, the ground light source coupling control unit is also equipped with a temperature compensation module to suppress the impact of ambient temperature changes on the RGB laser coupling accuracy.

[0010] Furthermore, the ground light source coupling and control unit is also equipped with a dual-parameter dynamic light color calibration module, which is used to collect fiber optic transmission distance data and downhole dust concentration feedback data, and dynamically adjust the red, green and blue laser output power of the RGB laser light source module according to the data, so as to compensate for the impact of long-distance light transmission attenuation and dust scattering on the light output effect.

[0011] Furthermore, the fiber optic sensing unit includes several sequentially connected optical fibers and FBG sensors embedded in the fiber core and distributed at preset intervals along the fiber length. Each optical fiber segment has coded markers at both ends to identify the coordinate information of the corresponding downhole location. The FBG sensors are used for the acquisition of global fault coordinate location information of the fiber optic sensing unit.

[0012] Furthermore, the light-emitting structure is provided with a microlens array and a diffuse reflection coating.

[0013] Furthermore, the downhole lighting output unit has a built-in explosion-proof LED backup light source, which is electrically connected to the intrinsically safe power supply in the well. When the fiber optic sensing unit transmission is interrupted or the ground light source coupling and control unit fails, the explosion-proof LED backup light source will automatically start to provide emergency lighting.

[0014] According to a second aspect of the present invention, a method for using a lighting system for explosive environments as described above is provided, comprising the following steps: The ground-based RGB laser light source is activated. After being combined by the coupling structure, the laser beam is transmitted forward to the downhole lighting output unit through the fiber optic sensing unit. The dual-parameter dynamic light color calibration module dynamically adjusts the RGB laser output power based on feedback data of fiber optic transmission distance and downhole dust concentration. The downhole lighting output unit outputs white lighting light that matches the visual requirements of downhole operations through the light-emitting structure. The safety monitoring unit collects data in real time, and transmits it to the linkage control unit after preprocessing. The linkage control unit divides the received data into three states: normal, warning, and danger. In the normal state, the current lighting parameters are maintained; in the warning state, the laser power is reduced to a preset percentage of the rated power, triggering an audible and visual warning and switching to local key lighting mode; in the danger state, the laser power is reduced to a preset percentage of the rated power, and the mine ventilation system is linked to enhance ventilation and the access control system is linked to seal off the work area. When an interruption in fiber optic transmission or a light source failure is detected, the underground lighting output unit automatically activates the explosion-proof LED backup light source. At the same time, the fault location is located by fiber optic coding and fed back to the linkage control unit. After the fault is cleared, the system automatically returns to normal operation.

[0015] Compared with the prior art, the beneficial effects of the present invention are: 1. This system integrates the RGB laser light source module into the ground light source coupling and control unit, which is set in a safe area on the ground. The pure light is transmitted underground only through the fiber optic sensing unit. There are no electrical equipment, power supply lines, or electro-optical conversion processes, achieving absolute photoelectric separation and completely eliminating the risk of explosion caused by electrical sparks, short circuits, and heat accumulation underground. It is suitable for the stringent safety requirements of high-gas and other explosive underground environments.

[0016] 2. By using an RGB laser light source module paired with a PLC optical waveguide combiner and an end-face alignment coupler, and combining this with a temperature compensation module to suppress the impact of environmental temperature differences on coupling accuracy, the coupling efficiency is kept stable at over 88%, effectively reducing brightness attenuation during long-distance transmission. Simultaneously, a dual-parameter dynamic light color calibration module dynamically adjusts the output power of red, green, and blue lasers based on feedback data from fiber optic transmission distance and downhole dust concentration. This compensates for the impact of long-distance light transmission attenuation and dust scattering on the light output effect, enabling the downhole lighting output unit to stably output 4000K-5000K white light through a light output structure composed of a microlens array and a diffuse reflection coating. The light output uniformity is ≥90%, ensuring visual comfort for operators while avoiding strong direct light interference, meeting the lighting needs of long-distance, complex downhole environments.

[0017] 3. This system constructs a fully closed-loop collaborative system. The safety monitoring unit achieves full-area coverage and precise local dual monitoring of underground gas concentration, temperature, dust concentration, fiber optic stress, and equipment operating status through a global monitoring module (relying on the FBG sensor and TDLAS sensing technology built into the fiber optic sensing unit) and a local monitoring module (including a miniature laser dust sensor and an independent explosion-proof sensor). The monitoring data is fed back to the linkage control unit in real time. The linkage control unit divides the monitoring data into three states: normal, warning, and danger. It dynamically adjusts the lighting parameters (e.g., adjusting to 50% of the rated power in the warning state and to 30% in the danger state), switches the lighting mode (local key lighting), and links with the mine ventilation and access control systems. This solves the data silo problem caused by the separation between traditional lighting and monitoring systems, realizes intelligent collaboration between lighting and safety monitoring, and improves the safety and efficiency of underground operations.

[0018] 4. The fiber optic sensing unit of this system can quickly and accurately locate the coordinates of fiber optic faults through the coded markings at both ends of each fiber optic segment and the FBG sensors distributed along the preset spacing of the fiber core. The downhole lighting output unit has a built-in explosion-proof LED backup light source, which is electrically connected to the intrinsically safe power supply in the well. When the transmission of the fiber optic sensing unit is interrupted or the ground light source coupling and control unit fails, the backup light source will automatically start to provide emergency lighting, so as to avoid the sudden interruption of lighting from affecting the operation or escape.

[0019] 5. The fiber optic sensing unit breaks through the limitations of traditional single-function fiber optics, simultaneously undertaking the dual tasks of forward transmission of lighting lasers and reverse transmission of monitoring data. It eliminates the need for additional sensing fiber optic cables, reducing underground installation work and lowering installation costs by 30%-40%, while also saving limited roadway space. The overall system structure design balances modularity and integration. Modules such as the ground light source coupling and control unit, fiber optic sensing unit, and underground lighting output unit have clearly defined functions, are easy to install and debug, and, combined with historical data storage and traceability functions, provide data support for mine safety management and system optimization. It is both technologically innovative and adaptable to actual underground engineering application scenarios, facilitating widespread adoption. Attached Figure Description

[0020] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 This is a schematic diagram of the structure of a lighting system for explosive environments according to the present invention; Figure 2 This is a schematic diagram of the structural block of the ground light source coupling and control unit described in this invention; Figure 3 This is a schematic diagram of the structure of the downhole lighting output unit described in this invention; Figure 4This is a flowchart of a method for using a lighting system for explosive environments according to the present invention; Figure 5 This is a schematic diagram of the ground light source coupling and control unit described in this invention; Figure 6 This is a schematic diagram of the structure of the downhole lighting output unit described in this invention. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of the present invention can be combined with each other, and the described embodiments are only some embodiments of the present invention, not all embodiments.

[0022] It should be noted that the descriptions of "left," "right," "left side," "right side," "upper part," "lower part," "top," and "bottom" in this invention are defined based on the orientation or positional relationships shown in the accompanying drawings. They are merely for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the described structure must be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0023] In the description of this invention, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0024] Referring to the accompanying drawings, this embodiment describes a lighting system for explosive environments, comprising a ground-based light source coupling and control unit, an optical fiber sensing unit, an underground lighting output unit, a safety monitoring unit, and a linkage control unit. The ground-based light source coupling and control unit connects to the optical fiber sensing unit via an explosion-proof optical fiber connector, transmitting lighting signals in the forward direction and simultaneously communicating bidirectionally with the linkage control unit via an industrial Ethernet. The optical fiber sensing unit connects to the ground unit and the underground lighting output unit at both ends, transmitting multi-parameter monitoring data in the reverse direction, and its grounding end is connected to the full-link grounding system. The underground lighting output unit receives the lighting signals transmitted via optical fiber, communicates with local explosion-proof sensors via Bluetooth to aggregate the data, and then uploads it to the linkage control unit via optical fiber. Its circuit end is connected to an intrinsically safe underground power supply and supplies power to the backup light source. In the safety monitoring unit, the global sensing module is embedded in the optical fiber core layer, and the local sensing module wirelessly connects to the underground lighting unit. The pre-processed data is uploaded to the linkage control unit. The linkage control unit aggregates the data of the entire system via an industrial Ethernet and issues control commands, while simultaneously linking the ground-based audible and visual warning device, the mine ventilation and access control system, and supports dual-mode control of remote ground control and local underground control.

[0025] The ground-based light source coupling and control unit is located in a safe area on the ground, avoiding the risks of heat sources and electrical hazards underground. As the core of the system's light source and the central hub for coupling and control, it includes an RGB laser light source module, a coupling structure, a dual-parameter dynamic color calibration module, and a linkage control interface. The RGB laser light source module uses red (650nm), green (532nm), and blue (450nm) semiconductor lasers, with a single laser output power adjustable from 0-10W. It features high brightness, low attenuation, and long lifespan, adaptable to the needs of long-distance underground transmission. The coupling structure is equipped with a PLC optical waveguide combiner and a precise end-face alignment coupler, integrating a collimating lens, a focusing lens, and a three-dimensional alignment adjustment structure, achieving an adjustment accuracy of ±0.01mm. Simultaneously, a temperature compensation module composed of a semiconductor cooler (TEC) is added to suppress the impact of ambient temperature differences (-20℃-40℃) on coupling accuracy, stabilizing the coupling efficiency at over 88% and ensuring brightness and color stability after long-distance transmission.

[0026] The dual-parameter dynamic light color calibration module incorporates a microprocessor and preset algorithms. Based on the fiber optic transmission distance and the concentration of dust in the well, it dynamically adjusts the RGB three-color light power ratio. The specific implementation process of the algorithm is as follows: First, a mapping database between transmission distance and the basic RGB power ratio is established. Preset basic ratio parameters for different transmission distances, such as 500m, 1000m, 1500m, and 2000m. The proportion of red light is fixed at 35%-40%, green light at 40%-45%, and blue light at 15%-25%. For every 500m increase in transmission distance, the total power increases by 10% to compensate for link attenuation. Then, the well dust concentration is introduced as a fine-tuning factor, and a linear correction algorithm is used. For every 10mg / m³ increase in dust concentration... 3The blue light power is increased by 2%-3%, while the red light power is simultaneously reduced by 1%-1.5% to ensure stable total power and unaffected color temperature. Finally, through closed-loop feedback calibration, the color temperature at the downhole light output is stabilized at 4000K-5000K, adapting to the vision requirements of downhole operations. The algorithm iteration cycle is 50ms, responding in real-time to changes in dust concentration and link attenuation.

[0027] The linkage control interface communicates with the linkage control unit via industrial Ethernet and receives safety level signals. When the underground gas concentration approaches the threshold (CH4 volume ratio reaches 0.8%), it automatically reduces the laser power to 30%-50% of the rated power and triggers a ground-based audible and visual warning. In case of a fault, it can receive control commands to turn off the light source or switch to standby mode.

[0028] As the core carrier of system signal transmission, the fiber optic sensing unit breaks through the limitations of traditional single-function optical fibers, realizing the dual tasks of light guiding and sensing, while possessing strong protective performance and adapting to the complex underground laying environment. Specifically, the optical fiber adopts MGXTSV type mining armored optical fiber, conforming to the MT / T 1117-2011 mining optical cable standard; the fiber core is made of quartz material, with a numerical aperture of 0.22 and an attenuation coefficient ≤0.2dB / km (1310nm wavelength); the outer layer is wrapped with a 1.2mm thick 316 stainless steel armored protective layer, and the interior is filled with epoxy resin sealant, which has wear resistance, tensile strength (breaking strength ≥1500N), anti-static performance, and grounding resistance ≤4Ω. Static electricity is conducted to the ground through the armor layer, avoiding the risk of sparks.

[0029] An FBG (Fiber Bragg Grating) sensor is embedded in the fiber core, with a grating period of 1550nm. One FBG sensor is embedded every 50 meters along the fiber core, with the embedding depth matching the core diameter, ensuring complete embedding at the core center. The spacing error between adjacent sensors is ≤±0.5 meters, ensuring comprehensive monitoring without blind spots and uniform data acquisition. Signal separation is achieved through wavelength division multiplexing (WDM) technology. The RGB laser illumination signal is transmitted forward along the fiber, while the sensing signal is transmitted backward, with no overlap in their wavelength ranges and no interference. Tunable laser absorption spectroscopy technology is integrated to detect methane concentration by detecting the characteristic absorption peak of CH4 at 1653.7nm. Combined with the inherent characteristics of the FBG sensor, downhole temperature (measurement range 50℃-150℃, accuracy ±0.5℃) and fiber stress (measurement range 0-1000με, accuracy ±10με) parameters are simultaneously acquired, enabling bidirectional transmission and triple parameter monitoring within the same fiber.

[0030] The optical fiber is wrapped in a flame-retardant sheath, and each fiber segment has a coded mark at both ends, corresponding to a unique coordinate position in the well, providing a basis for fault location; the fiber optic connector adopts an explosion-proof sealing structure to prevent dust and moisture from entering and affecting transmission performance.

[0031] The downhole lighting output unit is a downhole lighting terminal and a local monitoring node, integrating a light-emitting structure, explosion-proof design, and emergency protection functions. Specifically, it includes a light-emitting structure, an explosion-proof and local monitoring integrated module, and an emergency lighting and fault feedback module.

[0032] The light-emitting structure employs a composite design of "microlens array + diffuse reflection coating." The microlens array consists of 100×100 spherical microlenses with a diameter of 0.5mm and a focal length of 2mm. The diffuse reflection coating is made of alumina ceramic material with a reflectivity of ≥95%, avoiding direct glare and ensuring light uniformity of ≥90%, thus protecting the eyesight of workers. The specific dimensions of the light-emitting structure can be adjusted reasonably according to the actual lighting layout.

[0033] In the explosion-proof and local monitoring integrated module, the light-emitting end housing is made of cast aluminum alloy, anodized, and selected for mining applications, meeting explosion-proof standards; it incorporates a miniature laser dust sensor with a measurement range of 0.1-1000 mg / m³. 3 With a response time of less than 1 second, it collects local dust concentration data in real time and feeds it back to the linkage control unit via optical fiber; the housing has a reserved grounding terminal, which is connected to the armored optical fiber grounding link to form a full-link anti-static and explosion-proof system.

[0034] The emergency lighting and fault feedback module has a built-in 2W low-power explosion-proof LED backup light source with a color temperature of 4500K. When the optical fiber breaks or the light source fails, the backup light source is automatically activated by the optical fiber interruption signal, providing continuous basic emergency lighting with a battery life of ≥4 hours. At the same time, the fault location is fed back through optical fiber coding marking with an error of ≤1 meter, providing accurate positioning for maintenance and rescue.

[0035] The safety monitoring unit comprises a dual network of global distributed monitoring and local precision monitoring, providing reliable data support for intelligent control. It includes a global distributed monitoring module, a local precision monitoring module, and a data preprocessing module.

[0036] The full-area distributed monitoring module relies on fiber optic sensing units and uses FBG / TDLAS sensing technology to achieve full-area monitoring underground, covering the entire roadway. The gas concentration monitoring sensitivity reaches 0.001% of CH4 volume ratio, the temperature monitoring accuracy is ±0.5℃, the fiber optic stress monitoring accuracy is ±10με, and the response time is <1 second. It can capture safety hazards such as gas accumulation, temperature anomalies, and roadway stress changes in real time.

[0037] The local precision monitoring module adds independent explosion-proof sensors to the working face, roadway corners, and areas prone to gas accumulation. These include a gas sensor with a range of 0-10% CH4 and a temperature sensor with a range of -20℃ to 80℃, supplementing the blind spots of the overall monitoring. The sensors adopt an intrinsically safe design and establish a wireless communication link with the nearest underground lighting output unit via Bluetooth, with a communication distance of ≤10 meters. At the same time, it is equipped with frequency hopping anti-interference technology (frequency hopping interval of 1MHz) to resist underground electromagnetic interference and ensure stable data transmission. The data is uploaded to the ground via optical fiber and cross-validated with distributed monitoring data, with a monitoring error of ≤2%.

[0038] The data preprocessing module incorporates a built-in signal amplifier and filter, integrating sensor signal preprocessing algorithms to achieve interference removal, signal calibration, and format conversion. Specifically: First, a second-order Butterworth low-pass filter is used to reduce noise in the analog signals acquired by the FBG sensor, TDLAS sensor module, and local sensors, with a cutoff frequency set to 1kHz to eliminate downhole electromagnetic interference (50Hz power frequency interference and high-frequency noise) and dust scattering interference. Then, a linear calibration algorithm corrects the signal based on a preset standard signal curve, eliminating sensor zero-drift error and temperature drift. The calibration formula is: Ucal = Uraw × K + B, where Ucal is the calibrated signal, Uraw is the original acquired signal, K is the calibration coefficient (0.98-1.02), and B is the zero-bias correction value (-0.02V-0.02V). Finally, the calibrated analog signal is converted to a digital signal by a 16-bit ADC converter, and a CRC-16 checksum algorithm is used to verify data integrity. The checksum is transmitted synchronously with the data to avoid accidental triggering of control commands and ensure reliable data transmission.

[0039] The linkage control unit, as the central hub of the system, integrates data from various units and enables multi-dimensional intelligent linkage to ensure stable system operation. It includes a data fusion and decision-making module, a dual-mode control module, a data storage and traceability module, and an early warning module.

[0040] Specifically, the data fusion and decision-making module uses an STM32H7 series microcontroller as its core, equipped with an embedded operating system. It receives light color calibration data, fiber optic sensing data, and local monitoring data, and uses a weighted fusion algorithm and a state decision-making algorithm to determine the environment and system state. Details are as follows: Weighted fusion algorithm: Weight coefficients are assigned to monitoring data from different sources. The weight of FBG global sensing data is set to 0.4, TDLAS gas concentration data is set to 0.3, local sensor data is set to 0.2, and light and color calibration feedback data is set to 0.1. The fusion formula is: Dfuse = Σ(Di×Wi) (i=1,2,3,4), where Dfuse is the fused data, Di is the data of each module, and Wi is the corresponding weight. Weighted fusion reduces the measurement error of a single sensor and improves data reliability. State Decision Algorithm: Based on fused data, the algorithm compares it with preset thresholds to classify the system into three states: normal, warning, and dangerous. It also combines light source operating parameters and fiber optic transmission status to determine the system fault type and outputs the optimal control command. The algorithm's decision latency is <200ms, meeting the requirements for rapid downhole response. Specifically, under normal conditions, the gas concentration is <0.5%CH4, temperature ≤40℃, and fiber optic stress ≤500με; under warning conditions, the gas concentration is 0.5%-0.8%CH4, temperature is 40℃-50℃, and fiber optic stress is 500με-800με; under dangerous conditions, the gas concentration is ≥0.8%CH4, temperature is ≥50℃, and fiber optic stress is ≥800με.

[0041] The dual-mode control module supports both remote control from the ground and local emergency control downhole. The ground control terminal uses an industrial touch screen to display monitoring data and lighting parameters in real time, and allows manual adjustment of lighting modes, power, and color temperature. The downhole local control terminal is located in an explosion-proof distribution box and has emergency start / stop and mode switching functions. When the remote link is interrupted, it can operate independently to ensure that basic lighting and safety monitoring are not interrupted.

[0042] The data storage and traceability module is equipped with an 8GB industrial-grade storage chip to store lighting parameters, monitoring data, and control records, with a storage period of ≥90 days. It supports USB export and network upload, providing data support for mine safety management and system optimization. Simultaneously, it integrates a fault self-diagnosis algorithm. Based on sensor data, link signals, and equipment operating parameters, it quickly locates the fault type and location through threshold comparison and feature analysis, specifically as follows: When the fiber optic link signal is interrupted, the fault segment is located using fiber optic coding markers, with a location error ≤0.8 meters; when sensor data exceeds the normal fluctuation range (deviation >5%), it is judged as a sensor fault, distinguishing between zero drift fault and hardware damage; when there is no feedback on the light source power adjustment, it is judged as a fault in the light source module or coupling structure, generating a fault report containing the fault type, location, and troubleshooting suggestions, which is simultaneously uploaded to the ground control terminal and triggers an alarm. The fault self-diagnosis algorithm can be appropriately selected from existing algorithms based on actual conditions, and will not be elaborated further.

[0043] The early warning module outputs corresponding early warning signals according to the safety level: in the early warning state, it triggers a ground-based audible and visual early warning (volume ≥ 85dB, light flashing frequency 1Hz) and an underground local intrinsically safe audible and visual early warning; in the dangerous state, it links the mine ventilation system and access control system to achieve enhanced ventilation and sealing of the work area, forming multiple safety protections.

[0044] During installation, the ground light source coupling and control unit and the linkage control unit are fixed in the ground explosion-proof control room and connected to an AC220V / 50Hz industrial power supply. The three-dimensional alignment accuracy of the coupler is adjusted, and the influence of environmental temperature difference is calibrated through a temperature compensation module to ensure that the coupling efficiency is stable at over 88%. The RGB basic power ratio parameters corresponding to different transmission distances are preset, and the light color calibration algorithm is implanted. The fiber optic sensing unit is laid along the underground roadway and fixed at 1.5-meter intervals using armored fixing clips to avoid fiber optic stretching and wear. The fiber optic connectors are treated with explosion-proof seals, and the grounding link connection is reliable, ensuring that the grounding resistance is ≤4Ω. A unique code is marked at both ends of each fiber optic segment, corresponding to the underground coordinate position, to establish a fiber optic code-underground position mapping table. Install underground lighting output units at 5-8 meter intervals on the top of the roadway, and adjust the initial light output angle according to the roadway width; fix local explosion-proof sensors at the working face, roadway corners, etc., and establish Bluetooth communication links with the nearest lighting output unit to ensure that the distance between the sensor and the lighting unit is ≤10 meters and there are no obstructions affecting signal transmission; after all underground equipment is installed, check the explosion-proof level and grounding reliability to ensure compliance with mining safety standards; at the same time, verify the accuracy of the FBG sensor embedding position and correct the deviation of the distance between adjacent sensors.

[0045] After installation, the entire system was started to test the stability of RGB laser transmission and the consistency of downhole light output color temperature (measured at 4400K-4600K, with a deviation of ±100K). The sensor accuracy was calibrated using standard gas and temperature sources to ensure the accuracy of gas concentration, temperature, and stress monitoring data. Scenarios such as excessive gas concentration (CH4 volume ratio of 0.8%) and fiber optic breakage were simulated to verify the reliability of light source power control, early warning triggering, emergency lighting activation, and fault location functions.

[0046] When using: During normal operation, the ground-based RGB laser light source is activated. After being coupled by the PLC optical waveguide combiner and the end-face precision alignment coupler, the laser light is transmitted to the mine via the fiber optic sensing unit. The dual-parameter dynamic light color calibration module dynamically adjusts the RGB power based on the transmission distance and the dust concentration fed back from the mine. The mine lighting output unit outputs 4000K-5000K white light. The multi-parameter monitoring unit collects data in real time, and the linkage control unit determines that the status is normal, maintains the current parameters for continuous operation, and uploads and stores the data synchronously.

[0047] When the gas concentration is detected to be in the range of 0.5%-0.8%CH4, the temperature is >40℃, or the fiber stress is >500με, the system enters the early warning state; the linkage control unit commands the light source power to be reduced to 50% of the rated power, triggering the audible and visual early warning on the ground and underground, and at the same time switching the lighting mode to 30° local key lighting, focusing on the working face and escape route, to facilitate personnel operation and emergency evacuation.

[0048] When the gas concentration is ≥0.8%CH4, the temperature is ≥50℃, or the fiber optic stress is ≥800με, the system enters a dangerous state; the linkage control unit commands the light source power to be reduced to 30% of the rated power, retaining only basic lighting; at the same time, the linkage mine ventilation system increases the ventilation volume, triggers the access control system to seal off the work area, and prohibits personnel from entering; the underground local control unit operates independently to ensure that basic lighting and safety monitoring are not interrupted.

[0049] When the optical fiber breaks or the light source fails, the underground lighting output unit detects the optical fiber interruption signal and automatically activates the LED backup light source. At the same time, the fault location is located by marking the optical fiber with an encoding mark, and feedback is sent to the ground linkage control unit to trigger a fault alarm and generate a fault report. Maintenance personnel can quickly troubleshoot and repair the fault based on its location. After the fault is resolved, the system automatically restarts and switches back to normal operation.

[0050] This application constructs a fully closed-loop collaborative system through the above setup, eliminating data silos. It deeply integrates four cross-domain technologies: RGB laser lighting, distributed fiber optic sensing, mining explosion-proof, and intelligent linkage, forming a closed-loop system for monitoring, control, lighting, and feedback. Sensor data directly drives lighting parameter optimization, and the lighting system synchronously provides feedback on equipment operation and environmental safety status. Dual-parameter dynamic color calibration technology compensates for color shifts caused by long-distance transmission and counteracts the impact of dust scattering on visual effects, ensuring stable output of 4000K-5000K standard white light. The integrated fiber optic and sensing design eliminates the need for additional sensing cables, reducing installation costs by 30%-40%. Intelligent fault self-diagnosis and precise location functions significantly shorten maintenance time and improve maintenance efficiency by over 50%. Historical data traceability provides data support for safety management, balancing technological advancement with engineering practicality.

[0051] Most importantly, the light source and heat source are completely located in a safe area on the ground. The underground transmission is purely optical, without any electrical equipment, power supply lines, or electro-optical conversion process. This achieves absolute photoelectric separation, eliminating the safety hazards of electrical sparks, short circuits, and heat accumulation underground, and meeting the absolute safety requirements of high-gas environments in mines.

[0052] Based on field experiments, the key performance parameters of this system are as follows:

[0053] It fully meets the needs of downhole operations.

[0054] The embodiments of the present invention disclosed above are merely illustrative of the invention. These embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention.

Claims

1. A lighting system for use in explosive environments, characterized in that, include: The ground light source coupling and control unit is located in a safe area on the ground. It contains an RGB laser light source module for outputting RGB laser and a coupling structure for coupling and outputting the RGB laser. The fiber optic sensing unit is connected at one end to the ground light source coupling and control unit and at the other end to the underground lighting output unit located in an explosive environment. It is used to transmit the coupled laser to the underground lighting output unit in the forward direction and transmit monitoring data on the fiber optic usage status and underground safety hazards in the reverse direction. The downhole lighting output unit is equipped with a light-emitting structure for diffusing and outputting coupled laser light to form white light for illumination.

2. The lighting system for explosive environments according to claim 1, characterized in that: The system also includes a safety monitoring unit and a linkage control unit. The safety monitoring unit includes a global monitoring module and a local monitoring module. The global monitoring module is coupled to the fiber optic sensing unit to monitor the fiber optic usage status, and the local monitoring module is coupled to the downhole lighting output unit to monitor downhole safety hazard signals. Both the global monitoring module and the local monitoring module transmit the monitoring data to the linkage control unit.

3. A lighting system for explosive environments according to claim 2, characterized in that: The local monitoring module is equipped with a miniature laser dust sensor, which is used to collect local dust concentration data in the well in real time and feed it back to the linkage control unit through the fiber optic sensing unit.

4. A lighting system for explosive environments according to claim 1, 2, or 3, characterized in that: The RGB laser source module is a red, green, and blue semiconductor laser. The coupling structure is provided with a PLC optical waveguide combiner for combining the red, green, and blue lasers into a single beam and an end-face alignment coupler for connecting the combined RGB laser to the fiber end face of the fiber sensing unit. The end-face alignment coupler integrates a collimating lens, a focusing lens, and a three-dimensional alignment adjustment structure.

5. A lighting system for explosive environments according to claim 4, characterized in that: The ground-based light source coupling control unit is also equipped with a temperature compensation module to suppress the impact of ambient temperature changes on the RGB laser coupling accuracy.

6. A lighting system for explosive environments according to claim 4, characterized in that: The ground light source coupling and control unit is also equipped with a dual-parameter dynamic light color calibration module, which is used to collect fiber optic transmission distance data and downhole dust concentration feedback data, and dynamically adjust the red, green and blue laser output power of the RGB laser light source module according to the data to compensate for the impact of long-distance light transmission attenuation and dust scattering on the light output effect.

7. A lighting system for explosive environments according to claim 1, characterized in that: The fiber optic sensing unit includes several sequentially connected optical fibers and FBG sensors embedded in the fiber core and distributed at preset intervals along the length of the optical fibers. Each optical fiber has coded markers at both ends to identify the coordinate information of the corresponding downhole location. The FBG sensors are used for the acquisition of global fault coordinate location information of the fiber optic sensing unit.

8. A lighting system for explosive environments according to claim 1, characterized in that: The light-emitting structure is equipped with a microlens array and a diffuse reflection coating.

9. A lighting system for explosive environments according to claim 1, 2, 3, 5, 6, 7 or 8, characterized in that: The downhole lighting output unit has a built-in explosion-proof LED backup light source, which is electrically connected to the intrinsically safe power supply in the well. When the transmission of the fiber optic sensing unit is interrupted or the ground light source coupling and control unit fails, the explosion-proof LED backup light source will automatically start to provide emergency lighting.

10. A method of using a lighting system for explosive environments as described in claim 9, characterized in that, Includes the following steps: The ground-based RGB laser light source is activated. After being combined by the coupling structure, the laser beam is transmitted forward to the downhole lighting output unit through the fiber optic sensing unit. The dual-parameter dynamic light color calibration module dynamically adjusts the RGB laser output power based on feedback data of fiber optic transmission distance and downhole dust concentration. The downhole lighting output unit outputs white lighting light that matches the visual requirements of downhole operations through the light-emitting structure. The safety monitoring unit collects data in real time, and transmits it to the linkage control unit after preprocessing. The linkage control unit divides the received data into three states: normal, warning, and danger. In the normal state, the current lighting parameters are maintained. In the early warning state, the laser power is reduced to a preset percentage of the rated power, triggering an audible and visual warning and switching to localized focused lighting mode; in the dangerous state, the laser power is reduced to a preset percentage of the rated power, triggering the mine ventilation system to enhance ventilation and the access control system to seal off the work area. When an interruption in fiber optic transmission or a light source failure is detected, the underground lighting output unit automatically activates the explosion-proof LED backup light source. At the same time, the fault location is located by fiber optic coding and fed back to the linkage control unit. After the fault is cleared, the system automatically returns to normal operation.

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