A wireless ad hoc network system and control method for mine underground emergency communication

Abstract

The application discloses a wireless self-organizing network system and a control method for mine underground emergency communication, and relates to the technical field of communication. The wireless self-organizing network system comprises: a plurality of emergency self-organizing network nodes integrated in mine lamps, safety helmets or portable detectors and configured with low-power dual-mode communication modules; the emergency self-organizing network nodes automatically activate and build a mesh self-organizing network based on ultra-wideband when detecting that a main communication network is interrupted or a preset vibration threshold is triggered; at least one main control node performs route selection to optimize network topology; a ground receiving terminal is used for receiving data converged by the mesh self-organizing network and issuing rescue instructions; wherein the emergency self-organizing network nodes further collect the position, heart rate and surrounding gas concentration of a wearer; voice intercom communication is supported between the emergency self-organizing network nodes. The application quickly establishes a reliable temporary network without relying on fixed infrastructure after the main communication in the mine is interrupted.

Description

Technical Field

[0001] This application relates to the field of communication technology, and in particular to a wireless self-organizing network system and control method for emergency communication in underground mines. Background Technology

[0002] In the underground mining environment, the reliability of communication systems is directly related to personnel safety and emergency rescue efficiency. Currently, underground operations mainly rely on wired communication or wireless communication networks based on Wi-Fi / 4G for daily communication and data transmission.

[0003] However, in the event of sudden disasters such as landslides, gas explosions, or strong earthquakes, the main communication lines are easily interrupted, causing underground personnel to lose contact with the ground command center. Although some solutions have attempted to introduce self-organizing network technology to achieve local communication restoration, existing systems generally suffer from problems such as reliance on manual intervention for startup, slow network setup speed, low positioning accuracy, and limited coverage, making it difficult to quickly build a stable and high-precision emergency communication network within the "golden rescue time."

[0004] Crucially, existing underground emergency communication solutions struggle to quickly establish reliable temporary networks that do not rely on fixed infrastructure after the main communication is interrupted. They also generally suffer from problems such as delayed network response and insufficient positioning accuracy, failing to meet the comprehensive needs for real-time personnel positioning and efficient collaborative communication in disaster scenarios. This severely restricts the timeliness and accuracy of underground emergency response. Summary of the Invention

[0005] To address the shortcomings of existing technologies and to rapidly establish a reliable temporary network without relying on fixed infrastructure after the main communication in underground mines is interrupted, thus meeting the comprehensive needs for real-time personnel positioning and efficient collaborative communication in disaster scenarios, this application provides a wireless self-organizing network system and control method for emergency communication in underground mines.

[0006] Firstly, the objective of this invention is achieved through the following technical solution: A wireless self-organizing network system for emergency communication in underground mines includes: Multiple emergency self-organizing network nodes are integrated into mining lamps, safety helmets, or portable detectors, and are equipped with low-power dual-mode communication modules. When the emergency self-organizing network node detects an interruption of the main communication network or a preset vibration threshold is triggered, it automatically activates and constructs a mesh self-organizing network based on ultra-wideband. At least one master control node is located in an underground refuge chamber and equipped with a satellite communication module; the master control node performs routing to optimize the network topology; The ground receiving terminal is connected to the main control node via a satellite link and is used to receive personnel location information, vital sign data and environmental parameters gathered by the mesh self-organizing network, and to issue rescue instructions. The emergency self-organizing network nodes are equipped with sensor modules to collect the wearer's location, heart rate, and surrounding gas concentration; the emergency self-organizing network nodes support two-way voice communication.

[0007] By adopting the above technical solution, this invention integrates emergency self-organizing network nodes into personal devices such as mine lamps, safety helmets, or portable detectors, and configures them with low-power dual-mode communication modules (such as LoRa+UWB). This enables fully automatic, zero-latency activation when the main communication network is interrupted or a preset vibration threshold is detected. Utilizing ultra-wideband (UWB) technology for high-precision ranging and neighbor discovery between adjacent nodes, a stable mesh self-organizing network can be quickly constructed, achieving centimeter-level positioning accuracy, thus significantly improving networking speed and positioning accuracy. The main control node is deployed in the refuge chamber, possessing both satellite communication capabilities and intelligent routing functions. Simultaneously, each emergency self-organizing network node integrates multi-mode sensors to collect key safety parameters such as personnel location, heart rate, and surrounding gas concentration in real time during disaster scenarios. It also supports two-way voice communication between emergency self-organizing network nodes, enabling the ground receiving terminal to not only promptly grasp the status of personnel underground and environmental risks but also remotely issue precise rescue commands. This invention solves the core problem that existing underground emergency communication systems cannot autonomously, quickly, and with high precision rebuild reliable communication links after a disaster, significantly improving the survival rate and rescue efficiency in mine accidents.

[0008] In a preferred embodiment of this application: the main control node selects a relay node according to a routing algorithm that prioritizes distance and weights remaining power. In the routing algorithm, the distance priority uses the physical distance between adjacent nodes as the first weight, and the remaining power weight uses the percentage of remaining power of the relay node as the second weight. The preset vibration threshold corresponds to the vibration intensity reaching a preset level and the duration of the main communication network interruption reaching a preset time threshold.

[0009] By adopting the above technical solution, the emergency self-organizing network node automatically activates and builds a mesh self-organizing network when it detects that the main communication network is interrupted or the preset vibration threshold is triggered. The main control node establishes a connection with the ground receiving terminal, so as to realize the rapid start of emergency communication without manual intervention.

[0010] Secondly, the objective of this invention is achieved through the following technical solution: A control method for a wireless ad hoc network system for emergency communication in underground mines, the method comprising: At multiple emergency self-organizing network nodes, which are respectively integrated into mining lamps, safety helmets or portable detectors, the status of the main communication network and the intensity of environmental vibration are continuously monitored through low-power dual-mode communication modules. Monitor the status of the main communication network and the intensity of environmental vibration. When the duration of the main communication interruption reaches a preset time threshold or the vibration intensity reaches a preset level, the emergency self-organizing network node will be automatically activated. Each active node uses ultra-wideband communication technology to discover neighbors and measure distances accurately, forming an ultra-wideband mesh ad hoc network; The master control node collects distance and power information of each active node, calculates the optimal routing path based on a network topology strategy that prioritizes distance and weights the remaining power, and dynamically adjusts the relay node layout. The self-organizing network nodes continuously collect data on personnel location, heart rate, and gas concentration, and transmit it to the main control node. The main control node uploads the aggregated data to the ground receiving terminal via satellite communication and receives rescue instructions issued by the ground receiving terminal. It also supports voice communication between self-organizing network nodes and between self-organizing network nodes and the ground receiving terminal.

[0011] By adopting the above technical solutions, an end-to-end automated emergency response closed loop is formed, ensuring that the system can quickly self-organize and continue to operate after a disaster. Through centralized scheduling of the main control node and satellite backhaul, the efficient convergence of underground situation information to the ground command center is realized, while supporting the downlink communication of rescue commands and voice intercom, and building a two-way collaborative rescue communication channel.

[0012] In a preferred embodiment of this application, the dynamic adjustment of relay node layout includes the following closed-loop control steps: Each of the aforementioned emergency self-organizing network nodes periodically collects local communication performance indicators and reports them to the main control node; the local communication performance indicators include at least UWB link quality, signal strength, and the number of neighboring nodes; The master control node aggregates all reported local communication performance indicators and calculates global network performance indicators; the global network performance indicators include at least network connectivity, end-to-end average latency, and critical area coverage. The master control node compares the global network performance metrics with preset performance thresholds; if at least one global network performance metric is lower than the corresponding performance threshold, then: a) Identify weak communication areas based on the spatial distribution of performance indicators; b) Send a node scheduling instruction to the emergency self-organizing network node located around the weak communication area and meeting the first preset condition, instructing the emergency self-organizing network node to move to the weak communication area; c) Send a mode switching command to the emergency self-organizing network node located inside the weak communication area and meeting the second preset condition, so as to switch from normal communication mode to high-power relay mode; Upon receiving the instruction, the emergency self-organizing network node performs the corresponding movement guidance or working mode switching operation and returns an execution confirmation to the main control node. Return to the performance metric acquisition step and proceed to the next control cycle.

[0013] By adopting the above technical solutions, the limitations of passive adaptation in traditional ad hoc networks are overcome, enabling proactive intervention and self-healing of network topology. By filling coverage gaps through spatial scheduling and enhancing local links through function switching, the communication performance of key areas is dynamically maintained, significantly improving the resilience of the wireless ad hoc network system for emergency communication in mines under extreme disturbances such as roadway collapse or node disconnection.

[0014] In a preferred embodiment of this application, the first preset condition includes: the remaining power of the emergency self-organizing network node is higher than a first power threshold, and the distance from the current location to the center of the weak communication area is less than a preset distance threshold; The second preset condition includes: the emergency self-organizing network node is currently in an idle state or the data load is lower than the load threshold; The calculation method for the coverage rate of the key areas is as follows: The underground escape routes and work areas in the mine are divided into multiple grid units; if there is at least one emergency self-organizing network node in a certain grid unit or its corresponding neighborhood, and the signal strength reported by the emergency self-organizing network node is higher than the signal strength threshold, then the grid unit is determined to be covered. Critical area coverage = number of covered critical grid cells / total number of critical area grid cells.

[0015] By adopting the above technical solutions, the executability of scheduling instructions and the rationality of resources are ensured, and scheduling failures due to insufficient power or path congestion are avoided; idle nodes are converted into relays to maximize the use of idle communication capabilities; and the quantitative assessment of grid coverage focuses on risk avoidance routes and work areas, so that network optimization goals and safety requirements are precisely aligned.

[0016] In a preferred embodiment of this application: the calculation of global network performance metrics includes: The downhole operation area is divided into multiple communication assessment units; For each communication assessment unit, the communication interruption risk index is calculated based on the historical link interruption frequency, current vibration intensity change rate, and gas concentration gradient within the communication assessment unit; the communication service vulnerability index is calculated based on the number of personnel wearing emergency self-organizing network nodes, the average heart rate abnormality rate, and the average remaining power of the nodes within the communication assessment unit. The communication interruption risk index and the communication service vulnerability index are weighted and fused to obtain the emergency communication priority of the communication assessment unit; The calculation of the critical area coverage rate is performed only for communication evaluation units whose emergency communication priority is higher than the priority threshold.

[0017] By adopting the above technical solution, the underground area is divided into communication assessment units, and the communication interruption risk index and communication service vulnerability index are calculated separately to establish a two-dimensional risk assessment model, realizing a paradigm shift from "uniform coverage" to "on-demand support". High-risk areas reflect the risk of sudden environmental changes, and high-vulnerability areas reflect the vulnerability of personnel. The integration of the two allows communication resources to be prioritized for the most critical and needed areas, improving the efficiency of rescue resource allocation.

[0018] In a preferred embodiment of this application: the identification of weak communication areas prioritizes communication evaluation units with high emergency communication priority but current network connectivity rates below a preset connectivity threshold; the calculation formula for the communication interruption risk index D is: in, For the preset weighting coefficients, satisfy ; This is the normalized value of the rate of change of vibration intensity; This is the normalized value of the gas concentration gradient; This is the normalized value of the number of historical link interruptions.

[0019] By adopting the above technical solution, high-priority but low-connectivity communication assessment units are identified as weak areas, and a normalized multi-factor weighted formula is used to calculate the communication interruption risk index D, ensuring that repair actions are focused on "high-value but failed" areas and avoiding resource waste.

[0020] In a preferred embodiment, this application further includes: After receiving the execution confirmation, the main control node collects the local network performance indicators of the communication-weak area again. The local network performance metrics are compared a second time with the corresponding performance thresholds. If the local network performance indicators still do not reach the performance threshold, a communication degradation strategy instruction is triggered, instructing relevant emergency ad hoc network nodes to enable low-bandwidth voice coding or reduce the frequency of sensor data reporting; at the same time, the weak area identification and instruction generation steps are re-executed to generate a secondary adjustment instruction containing more emergency ad hoc network nodes or higher power.

[0021] By adopting the above technical solution, a secondary performance verification is performed after the instruction is executed. If the performance still fails to meet the standard, a communication degradation strategy is triggered. This invention constructs a hierarchical fault-tolerant mechanism that maintains a minimum level of communication capability even under extreme resource constraints (such as power depletion or sparse nodes). The degradation strategy ensures the accessibility of core voice commands, and the secondary adjustment attempts stronger intervention, forming a dual resilience architecture of "best effort + bottom-line guarantee".

[0022] In a preferred embodiment of this application, the weighted fusion of the communication interruption risk index and the communication service vulnerability index includes dynamically adjusting the weighting: For each communication evaluation unit, dynamic environmental parameters, including the rate of change of methane concentration, are collected in real time. and the rate of change of the proportion of abnormal heart rate ; Calculate the weight adjustment factor based on environmental dynamic parameters: Where α is the weight adjustment factor. These are preset coefficients that reflect the sensitivity to changes in gas concentration and heart rate, respectively. Dynamically update weighted weights: Weighting of the communication interruption risk index , Weights of the vulnerability index of communication services , in The initial fixed weights.

[0023] By adopting the above technical solution, the fusion weight of the hazard and vulnerability indices is dynamically adjusted according to the rate of change of gas concentration and the rate of change of the proportion of abnormal heart rate; the priority assessment is given dynamic adaptive capability; when gas suddenly increases, the hazard weight is automatically increased to strengthen the response to environmental risks; when the abnormal heart rate of the group intensifies, the vulnerability weight is increased to highlight the urgency of life rescue.

[0024] In a preferred embodiment of this application: before generating node scheduling instructions or mode switching instructions, the main control node further receives rescue mission area information sent from the ground receiving terminal; The main control node integrates the rescue mission area information with the emergency communication priorities of each communication assessment unit to generate a fused priority. If a communication assessment unit is located within the rescue mission area, then the communication assessment unit applies a preset priority gain coefficient to the emergency communication priority. The identification of weak communication areas and subsequent node scheduling and mode switching operations are all performed based on the fusion priority.

[0025] By adopting the above technical solution, the master control node integrates the rescue mission area information issued by the ground terminal, applies priority gain to the communication assessment unit in the mission area, and subsequent scheduling is executed based on the integrated priority; the ground command intention (such as the location of trapped personnel) is directly converted into the underground communication resource allocation strategy; the priority gain ensures that key rescue areas receive the highest level of communication support, opens up the decision-making and execution link, and significantly improves the accuracy and efficiency of the overall rescue operation.

[0026] In summary, this application includes at least one of the following beneficial technical effects: 1. This invention integrates an emergency self-organizing network node in a miner's lamp, safety helmet, or portable detector, a main control node in a refuge chamber, and a ground receiving terminal. The emergency self-organizing network node automatically activates and constructs a mesh self-organizing network when it detects an interruption in the main communication network or when a preset vibration threshold is triggered. The main control node establishes a connection with the ground receiving terminal through a satellite communication module and performs route selection to optimize the network topology. Emergency communication can be quickly initiated without manual intervention, achieving seamless integration of information exchange and rescue dispatch after the main communication network is interrupted. At the same time, the network topology can be optimized to maintain network stability. 2. Emergency self-organizing network nodes collect personnel location coordinates, heart rate data, and environmental gas concentration information in real time. Each node supports two-way voice communication, enabling personnel location sharing and multi-device collaboration, improving rescue efficiency, and ensuring that in emergency situations, distressed personnel can be quickly located and rescue operations can be carried out in a timely manner. Attached Figure Description

[0027] Figure 1 This is a system framework diagram of a wireless self-organizing network system for emergency communication in underground mines, according to one embodiment of this application. Figure 2 This is a flowchart of a control method for a wireless self-organizing network system for emergency communication in underground mines, according to one embodiment of this application. Figure 3 This is a flowchart of step S4 in the control method of a wireless self-organizing network system for emergency communication in a mine, according to an embodiment of this application. Detailed Implementation

[0028] The present application will be further described in detail below with reference to the accompanying drawings.

[0029] In one embodiment, such as Figure 1As shown, this application discloses a wireless ad hoc network system for emergency communication in underground mines, including multiple emergency ad hoc network nodes, at least one master control node, and a ground receiving terminal. The emergency ad hoc network nodes are integrated into mine lamps, safety helmets, or portable detectors, while the master control node is located in an underground refuge chamber. The emergency ad hoc network nodes must cooperate with the master control node to successfully establish the ad hoc network. The master control node then establishes communication with the ground receiving terminal, thereby enabling emergency communication and ensuring information exchange and rescue dispatch between ground and underground personnel when the main communication network is interrupted.

[0030] Specifically, the emergency self-organizing network node includes a low-power dual-mode communication module. This module features low power consumption; in this embodiment, LoRa and UWB dual-mode communication are used. LoRa communication is suitable for long-distance, low-speed communication, while UWB ultra-wideband technology enables high-precision positioning and fast data transmission. For example, in some underground coal mine environments, LoRa can provide signal coverage over a large area, while UWB can accurately determine the location of adjacent nodes. The low-power dual-mode communication module is typically installed inside the emergency self-organizing network node and connected to other components of the node via wiring. It can exist in the form of an integrated circuit board and is manufactured using low-power chips to reduce energy consumption.

[0031] The emergency self-organizing network node also includes environmental sensors and vital sign monitoring devices. Environmental sensors are used to collect real-time information on ambient gas concentration; this embodiment uses gas sensors, such as semiconductor gas sensors. Environmental sensors are generally installed on the outside of the emergency self-organizing network node for easy access to the external environment. Vital sign monitoring devices are used to collect personnel's heart rate data; common types include photoelectric heart rate sensors. These devices are typically placed close to the body, such as inside a safety helmet near the forehead or on the side of a miner's lamp near the face. Data collected by the environmental sensors and vital sign monitoring devices is transmitted via lines to a low-power dual-mode communication module, and then through the mesh self-organizing network to the main control node. Alternatively, environmental sensors can be other types, such as catalytic combustion gas sensors, and vital sign monitoring devices can be replaced with piezoelectric heart rate sensors.

[0032] In one embodiment, the emergency self-organizing network node has a built-in replaceable battery pack and a power monitoring unit. The replaceable battery pack typically uses lithium batteries, which are high in energy density, lightweight, and easy to replace. The battery pack is installed in the emergency self-organizing network node via a battery holder, facilitating removal and installation. The power monitoring unit monitors the battery pack's power level in real time. It can employ a power metering chip connected to the battery pack via a circuit, and then feeds back the remaining power information to the main control node. If lithium batteries are unsuitable in certain special environments, other types of batteries, such as nickel-metal hydride batteries, can be used as replacements.

[0033] The low-power dual-mode communication module enables emergency self-organizing network nodes to communicate with other nodes and build a self-organizing network. Environmental sensors and vital sign monitoring devices can collect personnel and environmental data. The battery pack powers the nodes, and the power monitoring unit provides power reference for the routing algorithm, ensuring the normal operation of the nodes.

[0034] Specifically, the main control node includes a satellite communication module. This module enables the main control node to establish a satellite communication connection with the ground receiving terminal, maintaining communication even if the ground base station is damaged. It typically consists of a miniaturized satellite communication antenna and modem, installed on the main control node's casing or in a suitable internal location. Data transmission and reception are achieved through connections to other components of the main control node. In remote mountainous areas or mines with weak communication infrastructure, different models of satellite communication modules with stronger anti-interference capabilities can be used as replacements.

[0035] The main control node also includes a routing module, which selects relay nodes based on a distance-first and remaining power-weighted routing algorithm. The routing module consists of a microprocessor and corresponding software programs. The microprocessor calculates the optimal relay node based on received information such as the physical distance between adjacent nodes and the remaining power percentage of each node. The routing module is installed inside the main control node and connected to satellite communication modules via lines to process and transmit data. A more powerful and efficient routing module can also be used to improve network optimization capabilities. In this embodiment, the distance-first routing algorithm uses the physical distance between adjacent nodes as the first weight, and the remaining power-weighted algorithm uses the remaining power percentage of the relay node as the second weight. The preset vibration threshold corresponds to a vibration intensity reaching a preset level and the main communication network interruption duration reaching a preset time threshold. The preset level is ≥5; the preset time threshold is ≥30 seconds.

[0036] The master control node also dynamically adjusts the network topology based on the real-time status information of nodes within the ad hoc network. Utilizing embedded intelligent algorithms, it comprehensively analyzes factors such as node location, power consumption, and communication quality to optimize the network topology, ensuring stable network operation. For example, when a node's power decreases or it malfunctions, the master control node will replan the routing path and select other suitable nodes as relays. The satellite communication module ensures communication with the ground, the routing module optimizes the network structure, and the dynamic adjustment of the topology guarantees network stability, enabling stable and efficient data transmission between the ground and underground ad hoc networks.

[0037] Specifically, the master control node periodically (e.g., every 5 seconds) or event-triggered (e.g., upon receiving a node anomaly report) collects real-time status information from each emergency self-organizing network node in the mesh network. This real-time status information includes the node's remaining battery power, its three-dimensional location coordinates, link communication quality indicators, and node operational status flags. The remaining battery power is expressed as a percentage, and the node's three-dimensional location coordinates are calculated using UWB ranging and trilateration algorithms. Link communication quality indicators include RSSI value and bit error rate (BER). Node operational status flags include normal, low battery warning, communication failure, and offline. This real-time status information serves as input parameters for the dynamic routing algorithm, which uses a weighted scoring model to comprehensively evaluate each potential relay node. The expression for the weighted scoring model is: ,in The overall score for node i; Let i be the current remaining battery level of node i; This is the baseline value for a fully charged battery. Let be the Euclidean distance from node i to the master control node; This is the distance threshold corresponding to the maximum communication radius of the network; The normalized communication quality factor has a value range of [0, 1] and is obtained by jointly mapping RSSI value and BER. The preset weighting coefficients sum to 1, and in this embodiment, they are set to a default value of 1. It can be dynamically adjusted according to the mine depth or disaster level.

[0038] Based on the above scoring results, the master control node constructs an optimal forwarding path set. If a relay node's battery level drops below 15% or it fails to respond to heartbeat packets three times consecutively (indicating a fault), it is immediately removed from the current routing table, and the path search is re-executed: prioritizing the comprehensive score. The top three most reliable nodes located between the source node and the master control node are designated as new relays to rebuild the multi-hop transmission link. This process is completed by the routing module calling the topology optimization engine. The updated routing table is broadcast to all nodes in the network via control signaling, ensuring that subsequent data is efficiently uploaded along the new path. Simultaneously, the satellite communication module maintains a continuous L-band narrowband satellite link with the ground receiving terminal, encapsulates the aggregated data into standard JSON format messages for periodic upload, and receives rescue instructions from the ground, which are then parsed and broadcast to relevant nodes via the ad hoc network.

[0039] The ground receiving terminal receives aggregated data transmitted from the main control node, including personnel location coordinates, heart rate data, and environmental gas concentration information. The ground receiving terminal is typically a computer or dedicated receiving device equipped with a display screen and data processing software. It receives data from the main control node via a network interface and displays it on the screen. Simultaneously, personnel at the ground rescue command center can send rescue commands to the main control node through the ground receiving terminal. Once received by the main control node, these commands are transmitted to designated emergency self-organizing network nodes via a mesh network.

[0040] Emergency self-organizing network nodes automatically activate when they detect a main communication network outage or a preset vibration threshold (vibration intensity reaches a preset level, and the duration of the main communication network outage reaches a preset time threshold, e.g., vibration intensity ≥ level 5 and main communication network outage ≥ 30 seconds). They then use ultra-wideband technology to discover neighboring nodes and measure distances, forming a mesh-like self-organizing network. These nodes collect personnel and environmental data in real time, transmitting the data to the main control node via the self-organizing network. The main control node then aggregates and sends the data to the ground receiving terminal. Upon receiving the data, the ground receiving terminal allows personnel to formulate rescue plans and send rescue instructions, which are transmitted to designated emergency self-organizing network nodes via the main control node and the self-organizing network. Simultaneously, two-way voice communication is supported between emergency self-organizing network nodes, and voice signals are also transmitted to the main control node via the self-organizing network. Furthermore, the environmental gas concentration data collected by the emergency self-organizing network nodes and the data analyzed by the main control node form a closed-loop feedback loop, used to adjust the communication parameters of the self-organizing network nodes. Through the collaborative action of the main control node and the emergency self-organizing network nodes, the self-organizing network forms a communication area with a coverage area of ​​at least 500 meters × 500 meters.

[0041] The implementation principle of this embodiment of a wireless self-organizing network system for emergency communication in underground mines is as follows: Emergency self-organizing network nodes are integrated into commonly used mine lamps, safety helmets, or portable detectors for convenient carrying and use by underground personnel. In the event of a main communication network outage or a seismic disaster, the emergency self-organizing network nodes can automatically activate and construct a mesh self-organizing network, quickly initiating emergency communication without manual intervention. A routing algorithm of "distance priority + remaining power weighting" is adopted, prioritizing nodes with sufficient distance and power as relays, ensuring network coverage while rationally utilizing node power and improving network stability. By collecting real-time personnel location, vital signs, and environmental data, and enabling voice communication between personnel, the ground rescue command center can promptly grasp the underground situation, formulate more precise rescue plans, and improve rescue efficiency. Simultaneously, a closed-loop feedback mechanism can adjust communication parameters based on environmental data to adapt to complex underground environments, further ensuring communication reliability. Compared to existing technologies, this system solves the problems of difficult emergency communication after a main communication network outage, small coverage of portable devices, and lack of collaborative functions, providing a more effective solution for emergency communication in underground mines.

[0042] In another embodiment, such as Figure 2 As shown, this application also discloses a control method for a wireless ad hoc network system for emergency communication in underground mines. This control method for a wireless ad hoc network system for emergency communication in underground mines is applied to the aforementioned wireless ad hoc network system for emergency communication in underground mines. The control method for a wireless ad hoc network system for emergency communication in underground mines specifically includes the following steps: S1: At multiple emergency self-organizing network nodes, which are respectively integrated into mining lamps, safety helmets or portable detectors, the status of the main communication network and the intensity of environmental vibration are continuously monitored through a low-power dual-mode communication module.

[0043] In this embodiment, the emergency self-organizing network node refers to a miniature communication terminal integrated into the personal equipment (such as a miner's lamp, safety helmet, or portable detector) of underground workers, which integrates sensing, communication, and power supply units. The low-power dual-mode communication module refers to a hardware module that simultaneously supports two different wireless communication protocols; in this embodiment, it is a combination of LoRa and Ultra-Wideband (UWB) dual-mode chips. The main communication network status refers to the connectivity of existing wired or conventional communication links such as 4G / Wi-Fi underground; the environmental vibration intensity is collected in real time by the triaxial accelerometer built into the emergency self-organizing network node, reflecting whether impact events such as collapses or explosions have occurred.

[0044] Specifically, each emergency self-organizing network node is in a low-power listening mode under normal operating conditions. The LoRa submodule in its low-power dual-mode communication module periodically sends a heartbeat signal to the well-up main control server to confirm that the main communication link is unobstructed. At the same time, the triaxial accelerometer in the emergency self-organizing network node continuously collects environmental vibration data and converts the vibration amplitude into a digital signal.

[0045] S2: Monitor the status of the main communication network and the intensity of environmental vibration. When the duration of the main communication interruption reaches a preset time threshold or the vibration intensity reaches a preset level, the emergency self-organizing network node is automatically activated.

[0046] In this embodiment, the preset time threshold refers to the shortest period of continuous disconnection after the main communication is interrupted, such as 30 seconds; the preset level refers to the judgment standard of vibration intensity, usually corresponding to a "level 5" disaster event with earthquake intensity or peak acceleration (e.g., ≥0.5g). Automatic activation refers to the emergency self-organizing network node switching from low-power listening state to full-function operation state, starting UWB communication, sensor acquisition and networking protocol stack.

[0047] Specifically, the microcontroller of the emergency self-organizing network node continuously compares the current main communication status with historical records: if no response is received from the main control server for 30 consecutive seconds, it is determined that the main communication interruption duration has met the standard; simultaneously, if the vibration peak value output by the accelerometer exceeds a preset threshold, activation is triggered if either condition is met. After activation, the node immediately turns on the UWB RF front-end, initializes the self-organizing network protocol stack, and illuminates the status indicator light. The entire process requires no manual intervention, and the response delay is less than 1 second. The microcontroller of the emergency self-organizing network node uses an STM32L4 series microcontroller.

[0048] S3: Each active node uses ultra-wideband communication technology to discover neighbors and measure distances accurately, forming an ultra-wideband mesh self-organizing network.

[0049] In this embodiment, Ultra-Wideband (UWB) communication technology is a wireless communication method based on nanosecond-level pulses. Neighbor discovery refers to a node actively broadcasting probe frames to identify other active nodes in its vicinity; accurate ranging calculates the distance between nodes using a two-way time-of-flight (TWR) algorithm. Mesh ad hoc networking refers to a network topology where each node can act as a relay, forming a multi-hop, decentralized mesh network.

[0050] Specifically, each activated emergency self-organizing network node broadcasts a UWB beacon frame containing its own ID and timestamp at fixed intervals (e.g., every 200 milliseconds). Upon receiving a beacon frame from another node, it immediately sends back a response frame, and both parties complete TWR ranging to obtain the Euclidean distance between them. All ranging results are used to construct a local adjacency list, and nodes autonomously join existing networks or initiate new network clusters based on this local adjacency list. Finally, all activated nodes complete self-organization within 5 seconds, forming a connected mesh structure with a coverage radius of not less than 250 meters.

[0051] S4: The main control node collects distance and power information of each active node, calculates the optimal routing path based on a network topology strategy that prioritizes distance and weights the remaining power, and dynamically adjusts the relay node layout.

[0052] In this embodiment, the master control node is a core gateway device deployed in the underground refuge chamber, which has stronger computing and communication capabilities; the distance and power information includes the distance measurement results between nodes and the remaining battery power percentage reported by each node.

[0053] Specifically, after the ad hoc network is established, the master control node broadcasts a topology query request to the entire network via the UWB link. Each emergency ad hoc network node responds and reports its distance measurement to the master control node and its current battery level. The routing module of the master control node receives this information and scores each potential relay path: the fewer the total hops and the higher the average battery level of the relay node, the higher the priority. Subsequently, the master control node generates an optimal routing table and sends it to the relevant nodes via control signaling. If the battery level of a relay node subsequently drops below the warning threshold, the master control node will re-execute this policy and dynamically replace the relay node.

[0054] S5: Self-organizing network nodes continuously collect personnel location, heart rate, and gas concentration data, and transmit them to the main control node.

[0055] In this embodiment, the personnel location is obtained by simple triangulation estimation from UWB ranging results, with an accuracy better than 2 meters. Heart rate is obtained by detecting changes in blood flow using a photoelectric sensor; gas concentration is measured by a semiconductor gas sensor to measure the volume fraction of combustible gases such as methane; data transmission refers to the data being forwarded to the main control node in a multi-hop manner through the routing path determined by the self-organizing network in step S4.

[0056] Specifically, after the emergency self-organizing network nodes are established, they synchronously collect three types of data at a frequency of 1Hz: location information is calculated in real time by the UWB module, heart rate data is output by a PPG sensor attached to the skin, and gas concentration is read by an external gas probe. These three types of data are packaged into a unified data frame and uploaded along the optimal route via the UWB link. If a hop link is temporarily interrupted, the data will be temporarily stored at an intermediate node and forwarded again once the path is restored.

[0057] S6: The main control node uploads the aggregated data to the ground receiving terminal via satellite communication and receives rescue instructions issued by the ground receiving terminal. It supports voice communication between self-organizing network nodes and between self-organizing network nodes and the ground receiving terminal.

[0058] In this embodiment, satellite communication refers to the main control node establishing communication with the ground via an L-band narrowband satellite link (such as BeiDou short message service or Inmarsat); the aggregated data is a collection of location, heart rate, and gas concentration information from multiple emergency ad hoc network nodes. Rescue instructions include text commands or voice broadcasts; voice intercom information interaction refers to supporting real-time voice calls between any two nodes, or between the ground and a designated node.

[0059] Specifically, the main control node integrates various types of sensor data received by timestamp and uploads them to the ground receiving terminal every 10 seconds via satellite communication module. Simultaneously, it continuously monitors downlink commands from the ground. Upon receiving a rescue command, the main control node parses the target node ID and forwards it via the ad hoc network; if it is a voice command, it first performs low-bit-rate encoding (such as AMR-NB) and then transmits it in packets. Furthermore, any two emergency ad hoc network nodes can initiate a voice conversation by pressing the PTT button; the voice stream is relayed through the ad hoc network to the other node, enabling local coordination underground. The main control node can also act as a voice relay station, allowing ground personnel to communicate directly with specific personnel underground.

[0060] In one embodiment, such as Figure 3 As shown, in step S4, the global network performance metrics are calculated, including: S41: Each emergency self-organizing network node periodically collects local communication performance indicators and reports them to the main control node; local communication performance indicators include at least UWB link quality, signal strength and number of neighboring nodes.

[0061] In this embodiment, local communication performance indicators are a set of quantitative parameters reflecting the current communication capabilities of a single emergency ad hoc network node. UWB link quality can be characterized by the Channel Impulse Response (CIR) energy or Bit Error Rate (BER) returned by the UWB module; signal strength refers to Received Signal Strength Indication (RSSI), measured in dBm; and the number of neighboring nodes refers to the total number of neighboring nodes that successfully established bidirectional ranging connections within the most recent neighbor discovery period. These local communication performance indicators are collected and cached in real-time by the microcontroller inside the emergency ad hoc network node. A microcontroller such as the STM32L476RG is used.

[0062] Specifically, each active emergency self-organizing network node performs a local performance evaluation at a fixed interval (e.g., every 8 seconds): First, it reads the link quality value from the UWB transceiver register; second, it obtains the RSSI of the strongest neighbor node through the radio front end; finally, it counts the number of valid entries in its adjacency table as the number of neighbor nodes. These three metrics are packaged into a structured data frame and sent to the corresponding master control node. If the report fails, it retryes in the next cycle, with a maximum of 3 retries before being marked as a link anomaly.

[0063] S42: The master control node summarizes all reported local communication performance indicators and calculates global network performance indicators; global network performance indicators include at least network connectivity, end-to-end average latency, and critical area coverage.

[0064] In this embodiment, network connectivity is defined as the ratio of the number of nodes currently in a connected state to the total number of active nodes; end-to-end average latency refers to the average round-trip time (RTT) for sending data packets from any edge node to the main control node, calculated using timestamp differences. Critical areas specifically refer to areas in the mine that are crucial to personnel safety, including escape routes and high-risk work areas, such as entrances to escape chambers, main roadway intersections, mining faces, and gas drainage stations; a critical area is considered covered if at least one normally functioning emergency ad hoc network node exists within a 50-meter radius, and the coverage rate is the ratio of the number of covered critical areas to the total number of critical areas.

[0065] Specifically, at the beginning of each control cycle (e.g., every 30 seconds), the master control node collects all local performance data successfully reported within the last 15 seconds. Based on this data, its internal processor performs the following calculations: Network connectivity = (Number of nodes receiving valid reports) / (Total number of known active nodes); End-to-end average latency = Arithmetic mean of RTT values ​​in all reported data frames.

[0066] The calculation method for the coverage rate of key areas is as follows: The underground escape routes and work areas in the mine are divided into multiple grid cells. If there is at least one emergency self-organizing network node in a certain grid cell or its corresponding neighborhood, and the signal strength reported by the emergency self-organizing network node is higher than the signal strength threshold, then the grid cell is considered covered. The coverage rate of the critical area = the number of covered critical grid cells / the total number of grid cells in the critical area. That is, the coverage rate of the critical area = checking whether the coordinates of each preset critical point fall within ±50 meters of any node location, and then calculating the ratio after counting the number of cases that meet the condition.

[0067] Specifically, a grid cell is a two-dimensional or three-dimensional spatial unit that divides the aforementioned area according to a fixed size. During the system initialization phase, the ground configuration software, based on the mine CAD drawings, divides all critical areas into square grid cells with sides of 30 meters × 30 meters (voxel division can be used in complex three-dimensional tunnels). Each grid cell is assigned a unique ID and stored in the geographic information database of the main control node. When calculating the coverage rate of critical areas in step S42, the main control node executes the following process: Traverse all critical grid cells; for each grid cell, check if there is at least one emergency self-organizing network node that satisfies the following: a) The physical location of the node falls within the grid cell, or falls within the eight neighboring grids of the adjacent grids in the top, bottom, left, right and four diagonal directions; b) The RSSI value reported by the emergency self-organizing network node most recently is ≥-80 dBm (i.e. the signal strength threshold is set to -80 dBm), indicating that the link quality is good; If both of the above conditions are met, the grid cell is determined to be "covered". The total number of covered critical grid cells is counted and divided by the total number of grid cells in the critical area to obtain the critical area coverage rate. For example, if a certain evacuation route is divided into 50 critical grids, and 42 of them meet the coverage conditions, then the critical area coverage rate is 42 / 50 = 84%.

[0068] In one embodiment, calculating global network performance metrics includes: S421: Divide the downhole operation area into multiple communication assessment units.

[0069] In this embodiment, the communication assessment unit is a basic spatial unit used to uniformly assess communication risks and service needs. The division is based on factors including tunnel topology, functional zoning, and historical accident data. The underground working area encompasses all tunnels, mining faces, transportation routes, and escape paths where personnel may be active.

[0070] Specifically, during the system deployment phase, the main control node loads the underground 3D digital model provided by the Mining Geographic Information System (GIS). Based on the underground 3D digital model, an adaptive grid partitioning algorithm is used to divide the working area into several communication assessment units: in structurally regular areas such as main roadways and intersections, square grids with sides of 50 meters × 50 meters are used; in irregular areas such as mining faces and chambers, polygonal subdivisions are performed according to the roadway boundaries to ensure that the internal environment of each unit is relatively homogeneous. Each communication assessment unit is assigned a unique ID and associated with its geographic coordinate range, functional type, and historical accident records. Functional types include transport roadways, coal mining faces, and emergency escape routes. The partitioning results are stored in the local database of the main control node. Specifically, the grid unit is used for determining the communication coverage status; the grid boundary is completely static, and only the coverage status changes dynamically. The communication assessment unit is used for risk and service vulnerability assessment; the unit boundary is statically preset, but internal indicators such as vibration, gas, and personnel are dynamically updated.

[0071] S422: For each communication assessment unit, calculate the communication interruption risk index based on the historical link interruption frequency, current vibration intensity change rate, and gas concentration gradient within the communication assessment unit; calculate the communication service vulnerability index based on the number of personnel wearing emergency self-organizing network nodes, the average heart rate abnormality rate, and the average remaining power of the nodes within the communication assessment unit.

[0072] In this embodiment, the communication interruption risk index reflects the possibility that the communication assessment unit's communication link will fail due to external disasters; the communication service vulnerability index reflects the degree of impact on personnel safety once communication is interrupted.

[0073] Specifically, the main control node calculates the communication interruption risk index and the communication service vulnerability index in each evaluation cycle. For identifying weak communication areas, priority is given to communication evaluation units with high emergency communication priority but current network connectivity below a preset connectivity threshold. In this embodiment, weak communication areas do not simply refer to areas with weak signals or few nodes, but rather to areas with high potential disaster risk, high personnel dependence, but poor current communication connectivity. Therefore, when executing step S43, the main control node no longer triggers optimization solely based on a decline in global performance indicators, but first selects units from all communication evaluation units that meet the following two conditions as candidates: An emergency communication priority P > priority threshold (e.g., 0.7) indicates that the communication area has high risk or high population density; If the current network connectivity rate is less than the preset connectivity rate threshold (e.g., 85%), it indicates that although the communication area is important, the actual communication quality is poor.

[0074] In practical applications, the master control node iterates through all communication evaluation units in each control cycle and performs the following judgment for each unit: If the P of the communication evaluation unit is greater than 0.7 and the current network connectivity is less than 85%, it is marked as a "communication evaluation unit to be optimized" and proceeds to the next step of analysis. Otherwise, skip this step and do not participate in this weak area identification.

[0075] Specifically, when calculating the vulnerability index of communication services, the number of personnel... The number of active nodes currently located within the communication evaluation unit (one node per person) was statistically analyzed and normalized to [0, 1] using Min-Max; the average heart rate abnormality rate was also measured. This refers to the percentage of nodes with a heart rate exceeding the 60–100 bpm range, directly used as a [0, 1] value; the average remaining battery power of the nodes. This refers to the average percentage of power consumption of all nodes within the communication evaluation unit, after inverse mapping (1− / 100) is converted into vulnerability contribution.

[0076] The vulnerability index of communication services is calculated using a weighted formula. The weighting coefficient The sum is 1, and the values ​​are taken in sequence, such as 0.5, 0.3, and 0.2.

[0077] The formula for calculating the communication interruption risk index D is: in, For the preset weighting coefficients, satisfy The values ​​are successively taken as 0.4, 0.3, and 0.3, and can be dynamically adjusted according to the type of mine, such as increasing the value for high-gas mines. ; This is the normalized value of the rate of change of vibration intensity. Take the maximum vibration change rate of all nodes in the communication evaluation unit within the past specified time period (e.g., 10 seconds), and normalize it to the interval [0, 1] using Min-Max; This is the normalized value of the gas concentration gradient. It refers to the spatial variation rate of methane concentration in the space within the communication assessment unit. When calculating, the maximum value of the gas concentration difference between adjacent nodes in the communication assessment unit is divided by the distance and then normalized to [0, 1]. The normalized value of the number of historical link interruptions refers to the frequency of UWB link interruption events within the communication evaluation unit during a specified time period (e.g., 7 days). The calculation requires counting the number of interruptions and normalizing it according to the highest interruption frequency in the entire mine.

[0078] S423: The emergency communication priority of the communication assessment unit is obtained by weighted fusion of the communication interruption risk index and the communication service vulnerability index.

[0079] In this embodiment, the formula for calculating the emergency communication priority P is: Among them, the fusion weight =0.6 indicates that in emergency scenarios, the focus is more on the probability of disasters occurring rather than just the number of people. Ultimately, P∈[0,1], and the higher the value, the higher the priority.

[0080] S424: The calculation of critical area coverage is performed only for communication assessment units whose emergency communication priority is higher than the priority threshold.

[0081] In this embodiment, when calculating the critical area coverage rate in step S42, the main control node first traverses all communication evaluation units, retaining only units that satisfy P>0.7 (i.e., the priority threshold is set to 0.7) as "effective critical units". Subsequently, the grid coverage determination logic of step S42 is applied to these "effective critical units", that is, checking whether there are nodes with a signal strength ≥ -80 dBm in their neighborhood. Finally, the critical area coverage rate = (number of covered effective critical units / total number of effective critical units).

[0082] For example, if the entire mine is divided into 200 communication evaluation units, and 60 of them have a P>0.7 value, then 50 of these 60 units are effectively covered, resulting in a critical area coverage rate of 50 / 60≈83.3%. This value will be used to trigger the topology optimization action in S43.

[0083] S43: The master control node compares the global network performance metrics with preset performance thresholds; if at least one global network performance metric is lower than the corresponding performance threshold, then: a) Identify weak communication areas based on the spatial distribution of performance indicators; b) Send node scheduling instructions to emergency self-organizing network nodes located around the weak communication area and meeting the first preset condition, instructing the emergency self-organizing network nodes to move to the weak communication area; c) Send a mode switching command to emergency self-organizing network nodes located in areas with weak communication and meeting the second preset conditions, so as to switch from normal communication mode to high-power relay mode.

[0084] In this embodiment, the preset performance thresholds are empirical values ​​configured during system initialization, such as: a network connectivity threshold of 85%, an end-to-end average latency threshold of 500ms, and a critical area coverage threshold of 90%. Weak communication areas refer to the set of spatial locations corresponding to global metric degradation, obtained by clustering the geographical coordinates of low-performance nodes.

[0085] Specifically, the master control node compares the calculated three global metrics with their corresponding thresholds. If any metric fails to meet the threshold, it initiates weak area identification: all reported nodes with RSSI < -85 dBm or neighbor count < 2 are clustered using DBSCAN to form one or more weak area centers. Subsequently, the master control node traverses the entire network node list: For nodes located around the weak area (e.g., within 50-150 meters of the center), check whether they meet the requirement of "remaining power > 40% and having mobility". If the mobility is installed on a mobile robot or a person-guided device, and the requirement is met, generate a node scheduling instruction to instruct it to move towards the center of the weak area. For nodes located within the vulnerable area (≤50 meters from the center), check if they currently have "no high-priority data transmission tasks." If so, generate a mode switching command, instructing them to increase their UWB transmit power from the default 10 dBm to 16 dBm, entering high-power relay mode. Both types of commands are issued via a reliable transmission protocol.

[0086] In this embodiment, the first preset condition includes that the current remaining battery power of the emergency self-organizing network node is higher than a first power threshold, and the distance from the current location to the center of the weak communication area is less than a preset distance threshold; here, the distance is the Euclidean distance between the three-dimensional coordinates obtained through UWB positioning and the cluster center of the weak area. In this embodiment, the first power threshold is set to 35%; the preset distance threshold is set to 150 meters; the specific values ​​can be customized as needed. The second preset condition includes: the emergency self-organizing network node is currently in an idle state or the data load is lower than the load threshold.

[0087] Specifically, when the main control node executes step S43, it first extracts the remaining battery power and current location coordinates of each node from the global node status table. Then, it performs a double check on each node located in the vicinity of a weak communication area (e.g., within 50 to 200 meters of the center): If its remaining power is ≥35%, it indicates that it has enough energy to support the additional power consumption during movement; Furthermore, the distance from the center of the vulnerable area is ≤150 meters, indicating that the movement path is feasible and the response is timely.

[0088] An emergency self-organizing network node is marked as a "schedulable node" and included in the target list for sending node scheduling instructions only if both conditions are met simultaneously. For example, if a miner's safety helmet node has a battery level of 37% and the miner is 120 meters away from the weak point, then the conditions are met; if the battery level is 32% or the distance is 180 meters, then the node is excluded.

[0089] In this embodiment, the second preset condition is used to screen emergency self-organizing network nodes suitable for increasing transmission power to enhance local coverage; wherein, being in an idle state means that the node is not participating in any data forwarding, voice calls or high-frequency sensing acquisition tasks; data load is lower than the load threshold means that the number of data packets processed per unit time or the CPU utilization rate is lower than the set upper limit; in this embodiment, the data load is judged by the number of data packets processed, and the upper limit is set such that the load threshold is set to ≤3 frames / second of data frames processed per second.

[0090] S44: Upon receiving the instruction, the emergency self-organizing network node performs the corresponding mobile guidance or working mode switching operation and returns an execution confirmation to the main control node.

[0091] In this embodiment, the movement guidance node guides the wearer to move in a designated direction through sound and light prompts or a vibration motor; the working mode switching node modifies the RF front-end configuration register to increase the output power; and the execution confirmation is a receipt message containing the operation result (success / failure) and the current status.

[0092] For example, upon receiving a scheduling command, the node immediately activates the guidance module: for instance, the LED array integrated into the safety helmet flashes in the direction of the arrow, while a buzzer emits intermittent beeps, guiding the miner to move towards the target coordinates. If it is an automated moving platform, the path planning algorithm is initiated to drive towards the target point. Upon receiving a mode switching command, the node calls the UWB driver API to write the power level parameters to the chip registers and disables unnecessary peripherals to compensate for increased power consumption. After the operation is complete, the node generates an acknowledgment frame and sends it back to the master control node.

[0093] After executing step S44, return to the performance metric acquisition step and enter the next control cycle.

[0094] In this embodiment, the next control cycle refers to the repeated execution of the closed-loop control process. The cycle length can be dynamically adjusted according to network stability, such as 30 seconds by default.

[0095] In one embodiment, a control method for a wireless ad hoc network system for emergency communication in underground mines further includes: S51: After receiving the execution confirmation, the master control node collects the local network performance indicators of the weak communication area again.

[0096] Specifically, execution confirmation refers to the successful acknowledgment returned by the emergency self-organizing network node after completing the movement guidance or working mode switch. After the master control node sends the scheduling or mode switch command to the target node, a verification waiting window (e.g., 15 seconds) is initiated. During this period, if execution confirmations are received from at least 80% of the target nodes, step S51 is immediately triggered. The master control node sends a local performance probe request to all nodes in the communication vulnerability area (including the original node and newly entered nodes), requiring them to report the following local indicators within 5 seconds: Average UWB link RSSI within the region, in dBm; The average number of neighbors between nodes within the region; End-to-end latency from the edge node to the master control node, in milliseconds (ms). The percentage of valid connected nodes in the region is calculated as: (Number of nodes that can successfully transmit data back) / (Total number of nodes in the region).

[0097] S52: Perform a secondary comparison between the local network performance metrics and the corresponding performance thresholds.

[0098] Specifically, the corresponding performance thresholds are acceptance criteria set for local areas and are more stringent than the global thresholds. For example, the master control node compares the collected local metrics with the preset local performance thresholds one by one. Typical thresholds include: average RSSI ≥ -75 dBm (better than the global -80 dBm); average number of neighbors ≥ 3; end-to-end latency ≤ 400 ms; and effective connected node ratio ≥ 90%. If any metric fails to meet the standard, it is determined that "the local network performance still does not meet the requirements," and the process proceeds to step S53.

[0099] S53: If the local network performance indicators still do not reach the performance threshold, a communication degradation strategy instruction is triggered, instructing relevant emergency ad hoc network nodes to enable low-bandwidth voice coding or reduce the frequency of sensor data reporting; at the same time, the weak area identification and instruction generation steps are re-executed to generate a secondary adjustment instruction containing more emergency ad hoc network nodes or higher power.

[0100] In this embodiment, the communication degradation strategy is a quality of service (QoS) compromise mechanism that sacrifices some functions to preserve core communication capabilities.

[0101] Specifically, the communication degradation strategy includes: the master control node broadcasting degradation instructions to all nodes within the communicationally vulnerable area, including optional actions such as enabling low-bandwidth voice coding and reducing the sensor data reporting frequency. Enabling low-bandwidth voice coding means that the emergency ad hoc network nodes switch their voice codec from the default AMR-WB (12.65 kbps) to G.729 (8 kbps) or Speex narrowband mode (2.15 kbps), significantly reducing the bandwidth usage of the voice stream. Reducing the sensor data reporting frequency involves lowering the original 1Hz heart rate / gas concentration acquisition frequency to 0.2 Hz.

[0102] The secondary adjustment command indicates that the master control node will not rely on the current optimization result, but will re-execute the weak area identification process in S43, but with a more aggressive strategy, including the following optional actions: Expand the range of candidate nodes: for example, relax the first preset condition "distance ≤ 150 meters" to "≤ 250 meters" to include nodes that are farther away but have sufficient power; Increased power limit: For the second preset condition node, the UWB transmit power is allowed to be increased to 20 dBm (originally 16 dBm), even if power consumption is increased; Forced multi-node collaboration: Generate joint scheduling instructions containing at least 3 relay nodes to build redundant paths.

[0103] For example, the first time only one node is moved, which is not effective; the second instruction will schedule three nodes to enter the vulnerable area from different directions and all of them will be turned on in high power mode to form a multi-hop backup link.

[0104] In one embodiment, in step S423, the communication interruption risk index and the communication service vulnerability index are weighted and fused, including dynamically adjusting the weighting: S4231: For each communication evaluation unit, real-time acquisition of dynamic environmental parameters, including the rate of change of gas concentration. and the rate of change of the proportion of abnormal heart rate .

[0105] In this embodiment, the originally fixed weighting coefficient (e.g., γ=0.6) is changed to be adjusted in real time according to dynamic environmental changes. Dynamic environmental parameters are key indicators reflecting the speed of disaster development and the rate of change in people's physiological state, used to quantify the urgency of the current situation. The methane concentration change rate is the change in methane concentration per unit time, expressed as %CH4 / s, reflecting the rate of methane accumulation or release. In this embodiment, the difference between the average concentration value of all gas sensors in the unit over the past 30 seconds and the average concentration value of the previous period is divided by the time interval. The average heart rate abnormality ratio change rate is the rate of change in the proportion of people with abnormal heart rates per unit time. An abnormal heart rate is defined as an average heart rate abnormality >100 bpm or <60 bpm. The average heart rate abnormality ratio change rate is the difference between the current abnormality ratio in the unit and the ratio of the abnormality ratio in the previous period, divided by the time interval.

[0106] S4232: Calculate the weighting adjustment factor based on environmental dynamic parameters. Where α is the weight adjustment factor. These are preset coefficients, reflecting the sensitivity to changes in gas concentration and heart rate, respectively. In this embodiment, we take... That is, under the same change, the impact of gas change is greater.

[0107] S4233: Dynamically update weighted weights: Weighting of the communication interruption risk index , Weights of the vulnerability index of communication services , in The initial fixed weight is set to 0.6.

[0108] In one embodiment, before generating node scheduling instructions or mode switching instructions, the master control node further receives rescue mission area information from the ground receiving terminal; S401: The main control node integrates the rescue mission area information with the emergency communication priorities of each communication assessment unit to generate a fused priority. If a communication assessment unit is located within the rescue mission area, the communication assessment unit applies a preset priority gain coefficient to the emergency communication priority.

[0109] In this embodiment, the rescue mission area information is a key instruction proactively issued by the ground receiving terminal based on the on-site disaster situation assessment, used to indicate the current key rescue areas. The main control node must prioritize processing the rescue mission area information before generating any scheduling or switching instructions.

[0110] Specifically, when the ground rescue command center identifies a certain area (such as the "east side tunnel of mining face No. 3") as the primary search and rescue target, the operator selects the area on the GIS interface of the ground receiving terminal and clicks "Issue Rescue Mission". The system automatically converts the area into a set of geographic coordinate boundaries and / or communication assessment unit IDs, and sends them to the main control node in JSON format via satellite link. The preset priority gain coefficient, such as 0.1 to 0.3, indicates that the priority of units within the area is increased.

[0111] After receiving the message, the main control node parses the message content and caches it as a currently valid rescue mission. The validity period is 30 minutes by default, and it can be renewed or canceled by the ground.

[0112] S402: The identification of weak communication areas and subsequent node scheduling and mode switching operations are all performed based on fusion priority.

[0113] In this embodiment, the fusion priority is the final priority after integrating the system's autonomous assessment and the intention of human command.

[0114] Specifically, after executing S423 (calculating the original priority P) and before S43 (weak area identification), the master control node inserts step S401: First, traverse all communication assessment units; for each communication assessment unit, determine whether its geometric center coordinates fall within the polygonal boundary of the rescue mission area. The determination method can be the ray cross method. If so, then apply a gain to its original priority P: =min(P+ΔP, 1.0), where ΔP = the preset priority gain coefficient, such as 0.2, with an upper limit of 1.0 to prevent overflow; otherwise, then =P.

[0115] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0116] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A wireless self-organizing network system for emergency communication in underground mines, characterized in that, include: Multiple emergency self-organizing network nodes are integrated into mining lamps, safety helmets, or portable detectors, and are equipped with low-power dual-mode communication modules. When the emergency self-organizing network node detects an interruption in the main communication network or a preset vibration threshold is triggered, it automatically activates and constructs a mesh self-organizing network based on ultra-wideband. At least one master control node is located in an underground refuge chamber and equipped with a satellite communication module; the master control node performs routing to optimize the network topology; The ground receiving terminal is connected to the main control node via a satellite link and is used to receive personnel location information, vital sign data and environmental parameters gathered by the mesh self-organizing network, and to issue rescue instructions. The emergency self-organizing network nodes are equipped with sensor modules to collect the wearer's location, heart rate, and surrounding gas concentration; the emergency self-organizing network nodes support two-way voice communication.

2. The wireless self-organizing network system for emergency communication in underground mines according to claim 1, characterized in that, The main control node selects a relay node based on a routing algorithm that prioritizes distance and weights the remaining power. In the routing algorithm, the distance priority uses the physical distance between adjacent nodes as the first weight, and the remaining power weight uses the percentage of the remaining power of the relay node as the second weight. The preset vibration threshold corresponds to the vibration intensity reaching a preset level and the duration of the main communication network interruption reaching a preset time threshold.

3. A control method for a wireless ad hoc network system for emergency communication in underground mines, characterized in that the method... include: At multiple emergency self-organizing network nodes, which are respectively integrated into mining lamps, safety helmets or portable detectors, the status of the main communication network and the intensity of environmental vibration are continuously monitored through low-power dual-mode communication modules. Monitor the status of the main communication network and the intensity of environmental vibration. When the duration of the main communication interruption reaches a preset time threshold or the vibration intensity reaches a preset level, the emergency self-organizing network node will be automatically activated. Each active node uses ultra-wideband communication technology to discover neighbors and measure distances accurately, forming an ultra-wideband mesh ad hoc network; The master control node collects distance and power information of each active node, calculates the optimal routing path based on a network topology strategy that prioritizes distance and weights the remaining power, and dynamically adjusts the relay node layout. The self-organizing network nodes continuously collect data on personnel location, heart rate, and gas concentration, and transmit it to the main control node. The main control node uploads the aggregated data to the ground receiving terminal via satellite communication and receives rescue instructions issued by the ground receiving terminal. It also supports voice communication between self-organizing network nodes and between self-organizing network nodes and the ground receiving terminal.

4. The control method for a wireless self-organizing network system for emergency communication in underground mines according to claim 3, characterized in that, The dynamic adjustment of relay node layout includes the following closed-loop control steps: Each of the aforementioned emergency self-organizing network nodes periodically collects local communication performance indicators and reports them to the main control node; the local communication performance indicators include at least UWB link quality, signal strength, and the number of neighboring nodes; The master control node aggregates all reported local communication performance indicators and calculates global network performance indicators; the global network performance indicators include at least network connectivity, end-to-end average latency, and critical area coverage. The master control node compares the global network performance metrics with preset performance thresholds; if at least one global network performance metric is lower than the corresponding performance threshold, then: a) Identify weak communication areas based on the spatial distribution of performance indicators; b) Send a node scheduling instruction to the emergency self-organizing network node located around the weak communication area and meeting the first preset condition, instructing the emergency self-organizing network node to move to the weak communication area; c) Send a mode switching command to the emergency self-organizing network node located inside the weak communication area and meeting the second preset condition, so as to switch from normal communication mode to high-power relay mode; Upon receiving the instruction, the emergency self-organizing network node performs the corresponding movement guidance or working mode switching operation and returns an execution confirmation to the main control node. Return to the performance metric acquisition step and proceed to the next control cycle.

5. The control method for a wireless self-organizing network system for emergency communication in underground mines according to claim 4, characterized in that, The first preset condition includes: the remaining power of the emergency self-organizing network node is higher than the first power threshold, and the distance from the current location to the center of the weak communication area is less than the preset distance threshold; The second preset condition includes: the emergency self-organizing network node is currently in an idle state or the data load is lower than the load threshold; The calculation method for the coverage rate of the key areas is as follows: The underground escape routes and work areas in the mine are divided into multiple grid units; if there is at least one emergency self-organizing network node in a certain grid unit or its corresponding neighborhood, and the signal strength reported by the emergency self-organizing network node is higher than the signal strength threshold, then the grid unit is determined to be covered. Critical area coverage = number of covered critical grid cells / total number of critical area grid cells.

6. The control method for a wireless self-organizing network system for emergency communication in underground mines according to claim 5, characterized in that, The calculation of global network performance metrics includes: The downhole operation area is divided into multiple communication assessment units; For each communication assessment unit, the communication interruption risk index is calculated based on the historical link interruption frequency, current vibration intensity change rate, and gas concentration gradient within the communication assessment unit; the communication service vulnerability index is calculated based on the number of personnel wearing emergency self-organizing network nodes, the average heart rate abnormality rate, and the average remaining power of the nodes within the communication assessment unit. The communication interruption risk index and the communication service vulnerability index are weighted and fused to obtain the emergency communication priority of the communication assessment unit; The calculation of the critical area coverage rate is performed only for communication evaluation units whose emergency communication priority is higher than the priority threshold.

7. The control method for a wireless self-organizing network system for emergency communication in underground mines according to claim 6, characterized in that, The identification of weak communication areas prioritizes communication assessment units with high emergency communication priority but current network connectivity rates below a preset connectivity threshold; the calculation formula for the communication interruption risk index D is as follows: in, For the preset weighting coefficients, satisfy ; This is the normalized value of the rate of change of vibration intensity; This is the normalized value of the gas concentration gradient; This is the normalized value of the number of historical link interruptions.

8. The control method for a wireless self-organizing network system for emergency communication in underground mines according to claim 7, characterized in that, The method also includes: After receiving the execution confirmation, the main control node collects the local network performance indicators of the communication-weak area again. The local network performance metrics are compared a second time with the corresponding performance thresholds. If the local network performance indicators still do not reach the performance threshold, a communication degradation strategy instruction is triggered, instructing relevant emergency ad hoc network nodes to enable low-bandwidth voice coding or reduce the frequency of sensor data reporting; at the same time, the weak area identification and instruction generation steps are re-executed to generate a secondary adjustment instruction containing more emergency ad hoc network nodes or higher power.

9. The control method for a wireless self-organizing network system for emergency communication in underground mines according to claim 6, characterized in that, The weighted fusion of the communication interruption risk index and the communication service vulnerability index includes dynamically adjusting the weighting: For each communication evaluation unit, dynamic environmental parameters, including the rate of change of methane concentration, are collected in real time. and the rate of change of the proportion of abnormal heart rate ; Calculate the weight adjustment factor based on environmental dynamic parameters: Where α is the weight adjustment factor. These are preset coefficients that reflect the sensitivity to changes in gas concentration and heart rate, respectively. Dynamically update weighted weights: Weighting of the communication interruption risk index , Weights of the vulnerability index of communication services , in The initial fixed weights.

10. The control method for a wireless ad hoc network system for emergency communication in underground mines according to claim 6, characterized in that, Before generating node scheduling instructions or mode switching instructions, the main control node further receives rescue mission area information from the ground receiving terminal. The main control node integrates the rescue mission area information with the emergency communication priorities of each communication assessment unit to generate a fused priority. If a communication assessment unit is located within the rescue mission area, then the communication assessment unit applies a preset priority gain coefficient to the emergency communication priority. The identification of weak communication areas and subsequent node scheduling and mode switching operations are all performed based on the fusion priority.

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