Intelligent mine safety production monitoring equipment internet of things control system and method

Abstract

This application relates to the fields of Internet of Things (IoT) and safety monitoring technology, and discloses an IoT control system and method for smart mine safety production monitoring equipment. In the system, IoT monitoring nodes collect environmental parameters according to a basic sleep-wake cycle under normal conditions. When the currently collected environmental parameters are determined to meet trend warning conditions, the node is designated as the event source node. The event source node calculates the wake-up delay time of the downstream target node based on the physical distance between the downstream target node and the event source node, and the equivalent propagation speed of the environmental parameters in the mine roadway. This invention utilizes the time difference in parameter propagation in physical space to achieve tiered wake-up of nodes, effectively reducing the overall network energy consumption while eliminating parameter acquisition lag.

Description

Technical Field

[0001] This invention relates to the fields of Internet of Things (IoT) and safety monitoring technology, specifically to an IoT control system and method for smart mine safety production monitoring equipment. Background Technology

[0002] In mine safety monitoring, IoT monitoring nodes are typically battery-powered, and node power consumption directly affects the lifespan of the monitoring network. To reduce overall system energy consumption, existing IoT monitoring nodes generally employ fixed sleep / wake cycles to collect environmental parameters.

[0003] This fixed-cycle control mechanism has limitations in dealing with sudden changes in environmental parameters. When an anomaly in environmental parameters occurs in the roadway and spreads outward, if nodes maintain low-frequency sampling, it is difficult to capture the out-of-limit changes in parameters during the interval between two wake-ups, easily leading to missed data and delayed alarms. To address this issue, some existing systems, after a local node triggers an early warning, will use network commands to synchronously switch all nodes in the network to high-frequency sampling. Due to the time delay in the propagation of environmental parameters in the physical space of the mine roadway, downstream nodes far from the anomaly source may prematurely enter high-frequency sampling before the parameters have spread and arrived, generating redundant sensor data and uplink communication traffic. This global synchronous wake-up mechanism causes nodes in non-out-of-limit areas to consume excess power, reducing the node's operating life and the available bandwidth of the communication network. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides an IoT control system and method for smart mine safety production monitoring equipment. It solves the problem that existing mine roadway IoT monitoring systems typically use a fixed sleep / wake cycle when collecting environmental parameters, making it difficult to balance overall node energy consumption with the real-time capture of abnormal parameters. Furthermore, maintaining a basic sleep state leads to data omissions and alarm delays when environmental parameters change abruptly.

[0005] To address the above problems, the present invention provides the following technical solution:

[0006] The first aspect of this invention provides an Internet of Things (IoT) control system for a smart mine safety production monitoring device, comprising multiple IoT monitoring nodes deployed in mine roadways; each IoT monitoring node includes a data acquisition module, a processing module, and a communication module.

[0007] The acquisition module is used to acquire environmental parameters according to the basic sleep-wake cycle under normal conditions.

[0008] The processing module is used to, when it is determined that the currently collected environmental parameters meet the preset trend warning conditions, take the current IoT monitoring node as the event source node, determine the theoretical arrival time of the environmental parameters spreading to the downstream target node based on the physical distance between the downstream target node and the event source node, and the equivalent propagation speed of the environmental parameters in the mine roadway, and determine a wake-up delay time less than the theoretical arrival time based on the theoretical arrival time.

[0009] The communication module is used to send a cascaded wake-up frame containing the wake-up delay time to the downstream target node;

[0010] The processing module is further configured to, when the current IoT monitoring node, as the downstream target node, receives the cascaded wake-up frame through the communication module, compensate for the communication processing delay caused by receiving and processing the cascaded wake-up frame based on the wake-up delay time, determine the local remaining waiting time, and after the local remaining waiting time has elapsed, control the acquisition module to switch the basic sleep-wake cycle to a high-frequency sampling cycle for acquiring the environmental parameters, so that the current IoT monitoring node switches to the high-frequency sampling cycle before the environmental parameters are expected to arrive; wherein, the duration of the high-frequency sampling cycle is less than the duration of the basic sleep-wake cycle.

[0011] This invention calculates the time it takes for environmental parameters to diffuse to downstream nodes by combining the propagation speed of environmental parameters with the physical distance between nodes. After detecting an anomaly in the environmental parameters, the event source node sends a cascaded wake-up frame containing a wake-up delay time, instructing downstream nodes to switch sampling frequencies only after this delay. Simultaneously, the waiting logic of the nodes compensates for the latency caused by communication and data processing. This design prevents downstream nodes from prematurely entering high-frequency sampling and consuming extra power, and avoids missed detections of anomalies caused by maintaining the basic sampling period, ensuring that the node state switching process matches the actual physical diffusion progress of the environmental parameters.

[0012] Furthermore, when the processing module determines that the currently collected environmental parameters meet the preset trend warning conditions, the specific operation performed is as follows: calculating the rate of change of the environmental parameters based on the environmental parameters collected at adjacent sampling times and the time interval between the adjacent sampling times; converting the rate of change according to the dangerous change direction corresponding to the environmental parameters to obtain the dangerous direction change rate; determining whether the dangerous direction change rate of the most recent consecutive preset number of times is greater than or equal to the rate of change threshold; if so, it is determined that the trend warning conditions are met.

[0013] Furthermore, the logic of the processing module in determining the theoretical arrival time and the wake-up delay time is as follows: dividing the physical distance by the equivalent propagation speed to obtain the theoretical arrival time of the environmental parameter diffusion to the downstream target node; multiplying the theoretical arrival time by a preset early wake-up margin coefficient to obtain the wake-up delay time; wherein, the early wake-up margin coefficient is a value greater than 0 and less than 1.

[0014] Furthermore, the logic of the processing module to compensate for the communication processing delay and determine the local remaining waiting time is specifically as follows: subtract the preset communication processing delay compensation time from the wake-up delay time to obtain the local remaining waiting time; when the local remaining waiting time is greater than zero, start the internal local timer, and control the acquisition module to continue to maintain the basic sleep-wake cycle during the local timer's timing period; when the local timer's timing duration reaches the local remaining waiting time, switch the acquisition module to the high-frequency sampling cycle; when the local remaining waiting time is equal to or less than zero, immediately switch the acquisition module to the high-frequency sampling cycle.

[0015] Furthermore, the processing module is also used to execute cascading forwarding logic: when the cascading wake-up frame is received, it determines whether the hop count limit parameter in the cascading wake-up frame is greater than zero; if the hop count limit parameter is greater than zero, it determines the next-hop associated node from the locally stored set of downstream topology associated nodes, identifies the next-hop associated node as the target node for the next-hop transmission, and decrements the hop count limit parameter by one; based on the physical distance between the current IoT monitoring node and the next-hop associated node, it recalculates the wake-up delay time corresponding to the next-hop associated node, and sends the updated cascading wake-up frame to the next-hop associated node through the communication module, the updated cascading wake-up frame including the hop count limit parameter decremented by one and the wake-up delay time corresponding to the next-hop associated node; if the hop count limit parameter is equal to zero, it no longer forwards the cascading wake-up frame to the next-hop associated node.

[0016] Furthermore, the cascaded wake-up frame includes an event identifier and at least one local hop target node wake-up entry. Each local hop target node wake-up entry includes at least a local hop target node identifier and a wake-up delay time corresponding to the local hop target node identifier. The processing module is used to extract the event identifier and the local hop target node identifier from each local hop target node wake-up entry after receiving the cascaded wake-up frame, and to match and verify the node network identifier of the current node with each local hop target node identifier. If the node network identifier of the current node matches any local hop target node identifier, the wake-up delay time in the successfully matched local hop target node wake-up entry is read, the current IoT monitoring node is determined to be the local hop target node corresponding to the current hop of the cascaded wake-up frame, and the current node is executed as the downstream target node with the delayed wake-up logic corresponding to the event identifier.

[0017] Furthermore, the system also includes an edge gateway that is communicatively connected to each of the IoT monitoring nodes; the edge gateway is used to obtain the current airflow velocity of the mine roadway, calculate the equivalent propagation velocity by combining the propagation correction coefficient corresponding to the environmental parameters, and periodically send it to each of the IoT monitoring nodes for the processing module to call.

[0018] Furthermore, the IoT control system also includes a central controller; the edge gateway further includes a bit-domain dynamic encoding module and an Ethernet unit communicatively connected to the bit-domain dynamic encoding module. The bit-domain dynamic encoding module includes a monitoring unit and a reassembly unit. The monitoring unit is used to monitor the wireless control channel and, upon detecting the cascaded wake-up frame, transmits the cascaded wake-up frame to the reassembly unit. The reassembly unit is used to extract the event identifier, the event source node identifier, and each local hop target node identifier from one or more cascaded wake-up frames corresponding to the same event identifier, and, based on the event source node identifier, each local hop target node identifier, and the node status information of each IoT monitoring node, determine the event path node set and the non-event path node set corresponding to the event identifier. The reassembly unit is also used to generate an uplink bit-domain encoded status frame corresponding to the event identifier, and allocate a first-length bit-domain code to the nodes in the event path node set, and allocate a second-length bit-domain code to the nodes in the non-event path node set, wherein the first length is greater than the second length. The Ethernet unit is used to transmit the uplink bit-domain encoded status frame generated by the reassembly unit to the central controller.

[0019] Furthermore, the environmental parameter is gas concentration; the processing module is also used to determine the over-limit hazard level corresponding to the current gas concentration according to at least one of the over-limit amplitude of the current gas concentration exceeding the preset over-limit alarm threshold and the rate of change of the current gas concentration along the concentration increase direction, according to a preset over-limit hazard level determination rule; determine the sampling frequency multiplication factor corresponding to the over-limit hazard level according to the preset mapping relationship between the over-limit hazard level and the sampling frequency multiplication factor, and determine the ratio of the basic sleep wake-up period to the sampling frequency multiplication factor as the high-frequency sampling period; wherein, the sampling frequency multiplication factor corresponding to the higher over-limit hazard level is not less than the sampling frequency multiplication factor corresponding to the lower over-limit hazard level, and the sampling frequency multiplication factor is a positive integer greater than 1.

[0020] A second aspect of the present invention provides an Internet of Things (IoT) control method for a smart mine safety production monitoring device, used to implement the aforementioned IoT control system for a smart mine safety production monitoring device, the method comprising the following steps:

[0021] Under normal conditions, multiple IoT monitoring nodes collect environmental parameters according to the basic sleep-wake cycle.

[0022] When any of the IoT monitoring nodes determines that the currently collected environmental parameters meet the preset trend warning conditions, it will act as the event source node.

[0023] The event source node determines the theoretical arrival time of the environmental parameters to the downstream target node based on the physical distance between the event source node and the downstream target node, and the equivalent propagation speed of the environmental parameters in the mine roadway, and determines a wake-up delay time that is less than the theoretical arrival time based on the theoretical arrival time.

[0024] The event source node sends a cascaded wake-up frame containing the wake-up delay time to the downstream target node;

[0025] The downstream target node receives the cascaded wake-up frame, compensates for the communication processing delay caused by receiving and processing the cascaded wake-up frame according to the wake-up delay time, determines the local remaining waiting time, and after the local remaining waiting time has elapsed, switches the basic sleep-wake cycle to a high-frequency sampling cycle to collect the environmental parameters, so that the downstream target node switches to the high-frequency sampling cycle before the environmental parameters are expected to arrive; wherein, the duration of the high-frequency sampling cycle is less than the duration of the basic sleep-wake cycle.

[0026] This invention provides an Internet of Things (IoT) control system and method for intelligent mine safety monitoring equipment. It has the following beneficial effects:

[0027] 1. This invention calculates the wake-up delay time based on physical distance and equivalent propagation speed by the event source node, and controls downstream nodes to switch to a high-frequency sampling period after this delay time. This feature allows downstream nodes to maintain a basic sleep state by utilizing the time difference in the propagation of environmental parameters in physical space, avoiding invalid communication and energy consumption caused by all nodes in the network concurrently switching to high-frequency sampling. At the same time, it ensures that the sampling frequency switch is completed before the environmental parameters actually arrive, solving the data omission and lag problems that are easily caused by fixed-period sleep.

[0028] 2. This invention obtains the current airflow velocity in the mine roadway through an edge gateway to dynamically calculate the equivalent propagation velocity, and periodically sends this data to each IoT monitoring node for processing module access. This feature allows the node's wake-up delay calculation to adapt to the dynamically changing ventilation environment within the roadway, avoiding time prediction deviations caused by relying on static parameters, and improving the control accuracy and environmental adaptability of the node's timed wake-up mechanism.

[0029] 3. This invention incorporates a dynamic bit-field encoding module in the edge gateway, allocating asymmetric-length bit-field encodings to the event path node set and the non-event node set to generate reporting status frames. This feature, while maintaining monitoring of the status of all nodes in the network, specifically compresses the data byte length of nodes in normally operating areas, reducing the uplink communication bandwidth usage between the edge gateway and the central controller. Attached Figure Description

[0030] Figure 1 This is a diagram of the overall architecture of the control system of the present invention;

[0031] Figure 2 This is a flowchart of the control method of the present invention;

[0032] Figure 3 This is a schematic diagram of the spatial topology initialization and parameter synchronization principle of the present invention;

[0033] Figure 4 This is a logic diagram of the local feedforward early warning determination of the present invention;

[0034] Figure 5 This is a timing diagram of the directional cascaded wake-up scheduling of the present invention;

[0035] Figure 6 This is a schematic diagram of the edge data frame reconstruction principle of the present invention;

[0036] Figure 7 This is a schematic diagram of the closed-loop linkage control principle of the present invention;

[0037] Figure 8 This is a schematic diagram comparing the effects of high-frequency sampling switching and peak capture in an embodiment of the present invention;

[0038] Figure 9 This is a schematic diagram comparing the total network energy consumption of the system in an embodiment of the present invention. Detailed Implementation

[0039] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] See attached document Figure 1 The present invention provides an Internet of Things (IoT) control system for a smart mine safety production monitoring device. The IoT control system includes sensor nodes, edge gateways, central controllers, and actuators.

[0041] Sensor nodes are deployed within mine roadways, and each sensor node forms a wireless sensor network via wireless communication. Each sensor node includes a sensing unit, a processing unit, and a first communication unit.

[0042] The sensing unit is used to collect environmental parameters to be measured. These parameters include at least one of the following: gas concentration, ambient temperature, dust concentration, and wind speed. The processing unit is connected to the sensing unit and is used to receive and buffer the environmental parameter values ​​at adjacent sampling times, and to calculate the first-order differential rate of change of the environmental parameters according to the sampling time interval.

[0043] The first communication unit is connected to the processing unit and is used to switch the working state according to the sleep-wake cycle determined by the processing unit, and to send or receive communication frames in the wireless control channel. When the processing unit determines that the sensor node is in a trend warning state or an over-limit alarm state based on the measured environmental parameter value and its first-order differential rate of change, the first communication unit broadcasts the corresponding node status information and directional cascaded wake-up frame in the wireless control channel.

[0044] The edge gateway connects to both the wireless sensor network and the industrial Ethernet backbone network. The edge gateway includes a second communication unit, a bit-domain dynamic coding module, and an Ethernet unit. The bit-domain dynamic coding module includes a monitoring unit and a reassembly unit.

[0045] The second communication unit is used to establish wireless communication with each sensor node and to send topology configuration data and segment equivalent propagation speed parameters to the sensor nodes.

[0046] The monitoring unit is used to monitor the wireless control channel and receive directional cascaded wake-up frames sent by the sensor nodes, and transmit the received directional cascaded wake-up frames to the reassembly unit.

[0047] The reassembly unit is used to extract the event identifier, event source node identifier, event source status code, topology direction identifier, and local hop target node identifier from the directional cascade wake-up frame, and, in conjunction with the node status information reported by each sensor node, determine the event path node set and non-event path node set corresponding to the corresponding abnormal event.

[0048] The reassembly unit is also used to arrange and encode the status bits of each sensor node according to the preset node arrangement order and status bit field encoding rules, and generate uplink bit field encoded status frames corresponding to the corresponding abnormal events.

[0049] In this context, the status bit fields of event path nodes are arranged in the event path node status area of ​​the uplink bit field encoded status frame, and the status bit fields of non-event path nodes are arranged in the non-event path node status area; event path nodes are encoded using bit field of a first length, and non-event path nodes are encoded using bit field of a second length, with the first length being greater than the second length.

[0050] The Ethernet unit is connected to the reassembly unit in the bit-domain dynamic coding module. It is used to receive the uplink bit-domain coding status frame generated by the reassembly unit and send the uplink bit-domain coding status frame to the central controller through the industrial Ethernet backbone network.

[0051] The central controller is located on the ground control side and includes a logic unit and a command issuing unit.

[0052] The logic unit receives the uplink bit-domain encoded status frame sent by the edge gateway, and parses the status bit fields of different nodes according to the bit-domain mapping table corresponding to the uplink bit-domain encoded status frame. The parsing result is converted into a unified node status table arranged according to the node network identifier. The unified node status table includes at least the node network identifier, communication connection status, environmental status, and topology location information.

[0053] The logic unit detects the current dangerous state of a node based on the current unified node status table and compares the current unified node status table with the unified node status table of the previous communication cycle to determine whether the node status has changed. When a node is detected to have entered a trend warning state, an over-limit alarm state, or an offline state requiring safety linkage or a sensor self-test fault state, the logic unit generates a status trigger signal.

[0054] The instruction issuing unit receives the status trigger signal output by the logic unit, and determines the actuator address and control instruction word corresponding to the corresponding sensor node or roadway area according to the preset topology linkage mapping table, and then generates the action instruction to be sent to the corresponding actuator.

[0055] The actuator is deployed on the downhole electrical equipment side and communicates with the central controller via a fieldbus. After receiving the action command from the command issuing unit, the actuator drives the relays, contactors, or other switching devices connected to it to change the energized or de-energized state of the connected electrical equipment.

[0056] After completing the action command, the actuator detects the actual operating status of the corresponding switching devices and returns the action result feedback to the central controller via the fieldbus. The action result feedback includes at least the corresponding information from the action command sequence number, action success status, action failure status, and actuator fault status. The central controller confirms the execution result of the action command based on the action result feedback, thus forming a closed-loop linkage control consisting of environmental parameter acquisition, status judgment, action command issuance, and action result feedback.

[0057] See attached document Figure 2 This invention provides an IoT control method for smart mine safety production monitoring equipment, comprising the following steps:

[0058] S100: The edge gateway sends topology configuration data to the sensor nodes and periodically sends segment equivalent propagation speed entries corresponding to different roadway segments through downlink beacon frames.

[0059] The topology configuration data should include at least the node network identifier of downstream associated nodes, the physical distance between adjacent nodes, the roadway segment identifier, and the propagation direction identifier. The segment equivalent propagation speed entry should include at least the roadway segment identifier, the type of environmental parameter being measured, the equivalent propagation speed, the data generation time, and the validity period.

[0060] The sensor node receives downlink beacon frames, extracts the matching equivalent propagation velocity and its validity period information based on the locally stored roadway segment identifier and the type of environmental parameter being measured, and updates the local velocity register. When the equivalent propagation velocity of a segment exceeds its validity period or fails the validity check, the sensor node uses a pre-stored conservative upper limit propagation velocity to calculate the subsequent wake-up delay time.

[0061] S200, the sensor node collects the measured environmental parameters according to the basic sleep-wake cycle, and calculates the first-order differential rate of change of the measured environmental parameters based on the current sampled value, the previous sampled value, and the time interval between adjacent sampling times.

[0062] The sensor node performs a sign transformation on the first-order differential rate of change based on the direction of hazard change of the measured environmental parameter, obtaining the hazard direction rate of change. For parameters where an increase in the measured value indicates an increase in the degree of danger, the hazard direction coefficient is set to 1; for parameters where a decrease in the measured value indicates an increase in the degree of danger, the hazard direction coefficient is set to −1. The hazard direction rate of change is the product of the hazard direction coefficient and the first-order differential rate of change.

[0063] When the current measured environmental parameter value has not yet reached the corresponding over-limit alarm threshold, and the rate of change of the dangerous direction for a consecutive preset number of sampling cycles has reached or exceeded the preset rate of change threshold, the sensor node determines that the current measured environmental parameter has a continuous trend of changing in the dangerous direction and enters the trend warning state.

[0064] For environmental parameters under test with an upper limit alarm threshold, the sensor node enters an over-limit alarm state when the current measured value reaches or exceeds the upper limit alarm threshold; for environmental parameters under test with a lower limit alarm threshold, the sensor node enters an over-limit alarm state when the current measured value reaches or falls below the lower limit alarm threshold.

[0065] S300: When a sensor node enters a trend warning state or an over-limit alarm state, the sensor node acts as an event source node, broadcasts a directional cascaded wake-up frame in the wireless control channel, and sets a long preamble sequence in the frame header of the directional cascaded wake-up frame.

[0066] The directional cascaded wake-up frame carries directional cascaded wake-up control information. The directional cascaded wake-up control information includes at least the event identifier, the event source node identifier, the event source status code, the topology direction identifier, at least one local hop target node identifier, the wake-up delay time corresponding to each local hop target node, the frame sequence number, the hop count limit parameter, and the event hold duration.

[0067] The downstream associated sensor node detects the energy characteristics of the long preamble sequence within the channel detection window. When the detection result meets the preset conditions, the downstream associated sensor node pauses and enters a sleep state while maintaining radio frequency reception until the reception and parsing of the directional cascaded wake-up frame is completed.

[0068] Downstream associated sensor nodes compare their own node network identifier with the local target node identifier in the directional cascade wake-up control information. When they belong to the local target node, the downstream associated sensor node uses the moment when the directional cascade wake-up control information parsing is completed as the local timing start point, and starts local timing according to the wake-up delay time corresponding to itself.

[0069] After the local timing period ends, the downstream associated sensor nodes will switch their sampling period from the basic sleep / wake-up period to a high-frequency sampling period. The high-frequency sampling period is shorter than the basic sleep / wake-up period.

[0070] Downstream associated sensor nodes also determine whether the received directional cascade wake-up control information has been processed based on the event identifier and frame sequence number. When the directional cascade wake-up control information is being received for the first time or the frame sequence number has been updated, and the hop count limit parameter is greater than zero, the downstream associated sensor node reads the locally stored set of downstream topology associated nodes, determines the next-hop associated node, recalculates the wake-up delay time corresponding to each next-hop associated node, decrements the hop count limit parameter by one, and forwards the new directional cascade wake-up frame to the next-hop associated node.

[0071] The S400 edge gateway listens to the wireless control channel, receives directional cascade wake-up frames sent by sensor nodes, and extracts the event identifier, event source node identifier, event source status code, topology direction identifier, local hop target node identifier, and frame sequence number from the directional cascade wake-up control information.

[0072] The edge gateway also receives node status messages sent by each sensor node, and establishes or updates the node status table based on the node network identifier, event identifier, current status code, status sampling time and message sequence number in the node status message.

[0073] The edge gateway aggregates all levels of directional cascaded wake-up frames belonging to the same event identifier, determines the event source node and the target node of the current hop recorded in each level of directional cascaded wake-up frame as the event path node of the corresponding abnormal event, and establishes or updates the event path node set accordingly.

[0074] The edge gateway performs bit-field encoding on the status of each sensor node based on the event path node set and node status table, generating an uplink bit-field encoded status frame corresponding to the corresponding abnormal event.

[0075] In the uplink bit-field encoded status frame, the edge gateway arranges the status bit fields of the event path nodes according to the priority of the event source node, the path order along the propagation direction, and the node network identifier order, and writes the arranged status bit fields continuously into the event path node status area; the status bit fields of non-event path nodes are written into the non-event node status area after the event path node status area.

[0076] The edge gateway writes the event identifier, frame layout sequence number, bit field mapping version number, data frame sequence number, and payload length into the frame header control field of the uplink bit-field encoded status frame. Each uplink bit-field encoded status frame corresponds to one abnormal event; when multiple abnormal events exist simultaneously, the edge gateway generates a corresponding uplink bit-field encoded status frame for each abnormal event.

[0077] Before adopting the new status bit field arrangement for the first time, the edge gateway sends the corresponding bit field mapping table and its bit field mapping version number to the central controller. The bit field mapping table is used to indicate at least the node network identifier, arrangement order, encoding type, status bit field start offset, and status bit field length of each node.

[0078] S500: The central controller receives the uplink bit-domain encoded status frame sent by the edge gateway, and obtains the bit-domain mapping table corresponding to the uplink bit-domain encoded status frame according to the frame layout sequence number and bit-domain mapping version number in the frame header control field.

[0079] The central controller parses the state bit fields in the event path node state area and non-event node state area according to the bit field mapping table, and converts the parsing results into a unified node state table arranged according to the node network identifier. The unified node state table includes at least the event identifier, node network identifier, communication connection status, environmental status, and topology location information.

[0080] The central controller compares the unified node status table of the current communication cycle with the unified node status table of the previous communication cycle to determine whether the node status has changed. At the same time, it detects whether each node is currently in a trend warning state, an over-limit alarm state, a sensor device self-test fault state that requires safety linkage, or an offline state.

[0081] When a change in node status is detected or a current dangerous state persists, the central controller generates a status trigger signal. The status trigger signal includes at least an event identifier, a node network identifier, the node's current state, and topology location information.

[0082] The central controller queries the preset topology linkage mapping table based on the status trigger signal to determine the actuator address and control command word of the actuator to be controlled, generates an action command with an action command sequence number, and sends the action command to the corresponding actuator through the fieldbus.

[0083] The actuator changes the energized or de-energized state of the connected electrical equipment according to the action command and returns the action result feedback to the central controller. The central controller matches the action result feedback with the corresponding action command according to the action command sequence number to confirm whether the action command was executed successfully, thus forming a closed-loop linkage control consisting of environmental parameter acquisition, status judgment, action command issuance, and action result feedback.

[0084] See attached document Figure 3 In this embodiment, the edge gateway first sends topology configuration data to each sensor node, and then periodically synchronizes the equivalent propagation velocity parameters of each roadway segment. The sensor nodes determine downstream associated nodes and calculate the corresponding wake-up delay time based on the locally stored topology configuration data and the currently valid equivalent propagation velocity parameters.

[0085] Before performing network initialization, the edge gateway receives a network topology table from the central controller. The network topology table is generated by the central controller based on the mine roadway construction drawings, ventilation direction, and the on-site deployment location of sensor nodes. It records at least the node network identifier of each sensor node, the connection relationship between nodes, the physical distance, the roadway section identifier, and the propagation direction identifier.

[0086] After the sensor nodes are deployed in the field, the second communication unit of the edge gateway sends a topology configuration message to the wireless sensor network under its jurisdiction via a wireless channel. The topology configuration message includes at least the identifier of the configured target node and the set of downstream topology associated nodes corresponding to the configured target node identifier. After receiving the topology configuration message, the sensor node extracts the corresponding set of downstream topology associated nodes based on its own node network identifier and writes it to its local non-volatile memory.

[0087] The downstream topology associated node set is used to record downstream associated nodes that are on the same measured environment parameter propagation path as the current sensor node. Each associated entry in the downstream topology associated node set includes at least the node network identifier of the downstream associated node, the physical distance between the current sensor node and the downstream associated node, the road segment identifier between them, and the propagation direction identifier.

[0088] To clarify the hierarchical relationship between different node terms, in this specification, a downstream associated node refers to a candidate node that establishes a downstream topological association with the current sensor node based on the roadway connection relationship and the propagation direction of the measured environmental parameters, and is recorded in the downstream topological associated node set; a downstream target node refers to a node that the current sensor node determines from one or more downstream associated nodes based on the propagation direction corresponding to the abnormal event, and that needs to receive cascade wake-up control and perform delayed wake-up; and a current hop target node refers to a downstream target node that is written into the current hop target node wake-up entry and is directly received by the current cascade wake-up frame during the current hop transmission of the cascade wake-up frame.

[0089] The same sensor node can have different node relationships with different sending nodes or different cascaded transmission hops. When the target node of the current hop receives the cascaded wake-up frame and continues to forward it downstream, it redetermines its downstream target node as the current forwarding node; the redetermined downstream target node constitutes the target node of the current hop in the next hop transmission.

[0090] In mine ventilation networks, hazardous gases, dust, or heat typically propagate along roadways and in the direction of airflow. Therefore, the downstream topological associated node set is determined according to roadway connections and airflow direction, indicating one or more downstream associated nodes corresponding to the current sensor node along the propagation direction of the measured environmental parameters. In areas with roadway branches, the same sensor node can correspond to multiple downstream associated nodes.

[0091] For any sensor node i, its downstream topologically associated node set Represented as:

[0092] ;

[0093] in, The node network identifier representing the downstream associated node j; This represents the physical distance between sensor node i and its downstream associated node j. The physical distance is determined based on the measurement results during on-site deployment. This represents the tunnel segment identifier between sensor node i and its downstream associated node j, used to match the equivalent propagation speed of the corresponding tunnel segment; This indicates the propagation direction from sensor node i to its downstream associated node j; This represents the set of downstream associated nodes of sensor node i, and its number of nodes is expressed as... .

[0094] After the sensor node saves the set of downstream topology associated nodes locally, it can determine the next-hop associated node based on the propagation direction identifier, and calculate the wake-up delay time corresponding to each next-hop associated node based on the physical distance and the road segment identifier, without having to query the topology relationship from the central controller every time a directional cascade wake-up frame is forwarded.

[0095] The edge gateway also obtains the segment equivalent propagation speed of each lane section and encapsulates the segment equivalent propagation speed into the downlink beacon frame.

[0096] The airflow velocity and propagation conditions of the measured environmental parameters within the mine may change with the operating status of ventilation equipment, roadway operation conditions, and variations in local resistance. The Ethernet unit of the edge gateway periodically receives the section environmental parameters sent by the propagation velocity parameter providing subsystem. The propagation velocity parameter providing subsystem serves as an external data source for the IoT control system, providing airflow velocities for each roadway section, or providing equivalent propagation velocities corresponding to the types of measured environmental parameters.

[0097] The equivalent propagation velocity of a section is expressed in meters per second and is represented by a scalar value greater than zero. The propagation direction of the measured environmental parameter is indicated separately by the propagation direction indicator and is not indicated by the sign of the equivalent propagation velocity of the section.

[0098] As a specific implementation method, the equivalent propagation velocity of a section can be determined in any of the following ways: directly using the airflow velocity detected by the wind speed sensor in the corresponding roadway section; multiplying the airflow velocity by a propagation correction coefficient pre-set according to the type of environmental parameter being measured; or establishing a correspondence table between roadway section identifiers, types of environmental parameters being measured, and equivalent propagation velocities based on historical calibration data, and querying the corresponding equivalent propagation velocity of the section according to the current roadway section identifier and type of environmental parameter being measured.

[0099] The edge gateway obtains the corresponding equivalent propagation speed for each lane segment based on the lane segment identifier and the type of environmental parameter being measured. This is to ensure that different roadway sections adopt velocity parameters corresponding to their ventilation conditions and the type of environmental parameters being measured.

[0100] Before transmitting the equivalent propagation speed of the segment, the edge gateway performs integrity checks, validity period checks, and value range checks on the acquired speed parameters. The preset valid speed range is expressed as follows: ,in, .

[0101] When the equivalent propagation speed data for a segment is missing, data verification fails, data expires, or the speed value is not within the preset valid speed range, the edge gateway will set the equivalent propagation speed for the segment used for distribution to a pre-configured conservative upper limit propagation speed. .

[0102] Conservative upper limit of propagation speed The wake-up delay time should not be less than the maximum equivalent propagation speed that the corresponding environmental parameter under test is expected to reach within the corresponding roadway section. Since the wake-up delay time is inversely proportional to the equivalent propagation speed of the section, the wake-up delay time calculated using the conservative upper limit propagation speed should not be later than the time calculated based on the expected maximum propagation speed. This avoids division-by-zero errors or delayed wake-up of downstream related nodes due to abnormally small or zero speed parameters.

[0103] The second communication unit will verify the equivalent propagation speed of the segment. The code is encoded as a fixed-length field, and the tunnel segment identifier, the type identifier of the measured environmental parameter, the equivalent propagation speed of the segment, the data generation time and the validity period are encapsulated into a segment propagation speed entry.

[0104] The second communication unit writes one or more segment propagation speed entries into the payload of the downlink heartbeat beacon frame and broadcasts the downlink heartbeat beacon frame within its jurisdiction's wireless sensor network according to a preset transmission period. The downlink heartbeat beacon frame also includes control fields for frame synchronization, frame type identification, and data verification.

[0105] The sensor node periodically opens its receiving window according to a preset communication duty cycle. The first communication unit receives the downlink heartbeat beacon frames broadcast by the edge gateway within the receiving window and transmits the downlink heartbeat beacon frames to the processing unit.

[0106] The processing unit parses the payload of the downlink heartbeat beacon frame according to the preset frame format and field offset, and then analyzes the tunnel segment identifiers of each associated entry in the locally stored downstream topology associated node set. In addition to the types of environmental parameters monitored by this node, one or more segment propagation speed entries that match are extracted.

[0107] The processing unit writes the extracted roadway segment identifier, the type of the measured environmental parameter, the equivalent propagation velocity of the segment, the data generation time, and the validity period into the local velocity parameter table. The local velocity parameter table includes velocity register entries corresponding to different roadway segments and different types of measured environmental parameters. Newly received and verified velocity parameters are used to update the corresponding velocity register entries.

[0108] Before calculating the wake-up delay time of downstream associated nodes, the sensor node checks the validity period of the corresponding velocity register entry again. If the velocity parameter is still valid, the processing unit uses the equivalent propagation speed for that segment for calculation; if the velocity parameter has expired, the corresponding velocity register entry does not exist, or the parameter verification fails, the processing unit uses a locally pre-stored conservative upper limit propagation speed. Perform the calculation.

[0109] Through the above processing, the sensor node can save the current effective velocity parameters corresponding to each of its downstream roadway sections, and use a conservative upper limit propagation speed to calculate the wake-up delay time when the velocity parameters are missing or invalid.

[0110] See attached document Figure 4 This embodiment further explains the process by which sensor nodes collect environmental parameters and determine trends for early warning. The process includes collecting environmental parameters, filtering sampled data, calculating the first-order differential rate of change, handling dangerous directions, and determining the node status.

[0111] The sensor node operates in low-power mode, and the processing unit's timer is configured with a basic sleep-wake cycle. As one specific implementation method, The time can be set from 1 to 10 seconds depending on the rate of change of the measured environmental parameters, the sensor response time, and the node power consumption requirements.

[0112] After each basic sleep-wake cycle The processing unit wakes up the sensing unit. The sensing unit collects the measured environmental parameters at the current moment and obtains the raw measurement values. The original measurement values ​​are then sent to the processing unit. This indicates the discrete sampling number corresponding to the current sampling time.

[0113] To reduce the impact of electromagnetic interference, momentary sensor obstruction, or transient anomalies caused by sampling circuit fluctuations on state determination, the processing unit performs digital filtering on the raw measurement values. As one specific implementation, the processing unit uses a moving average method to filter continuous... The original measurements are processed to obtain the measured environmental parameters at the current sampling time. :

[0114] ;

[0115] in, This represents the filtered measurement value of the environmental parameter at the t-th sampling time. Indicates the first The original measurement value obtained at each sampling time; t represents the discrete sampling sequence number corresponding to the current sampling time; m represents the historical sampling offset sequence number of the original measurement value within the filtering window relative to the current sampling time, m=0 indicates the current sampling time. Indicates the earliest sampling time within the filtering window; This indicates the number of raw measurements included in the filter window, and It is a positive integer not less than 2.

[0116] The processing unit includes a processor, RAM, non-volatile memory, and timers. The processing unit processes the filtered environmental parameters measured... The data is written sequentially to the circular buffer in the runtime memory.

[0117] A circular buffer is used to store the measured values ​​of environmental parameters at multiple consecutive sampling times, and its storage depth is not less than [amount missing]. .in, The threshold for the number of times the continuous rate of change exceeds the limit. This is achieved by saving at least... Each measurement processing unit can calculate continuous The first-order difference rate of change corresponding to each sampling period.

[0118] After system startup or sensor node reinitialization, if the annular buffer does not yet contain sufficient measured values ​​to determine the continuous rate of change, the processing unit only updates the sampled data and does not perform trend warning determination. The process continues until the number of valid measured values ​​stored in the annular buffer reaches a certain threshold. Then, the subsequent status determination is performed.

[0119] The processing unit reads the measured values ​​of the environmental parameters at the current sampling time from the circular buffer. The measured values ​​of the environmental parameters at the previous sampling time And based on the basic sleep-wake cycle Calculate the first-order difference rate of change for the current sampling period. :

[0120] ;

[0121] in, This represents the change in the measured environmental parameter per unit time within the current sampling period. For sensor nodes using a fixed baseline sleep / wake cycle, the time interval between two adjacent measurements is... When the actual sampling time interval changes, the denominator uses the actual time interval corresponding to two adjacent measurements.

[0122] The processing unit performs sign processing on the first-order differential rate of change based on the hazard change direction of the measured environmental parameter. The processing unit pre-stores hazard direction coefficients corresponding to the types of measured environmental parameters. The hazard direction coefficient is determined according to the following formula:

[0123] ;

[0124] For example, when increases in methane concentration, carbon monoxide concentration, dust concentration, and ambient temperature indicate an increased level of danger, the hazard direction coefficient... Set to 1; when a decrease in oxygen concentration or wind speed requiring a minimum value indicates an increase in the degree of danger, the hazard direction coefficient is set to 1. Take -1.

[0125] The processing unit will use the hazard direction coefficient With first-order difference rate of change Multiply to obtain the rate of change of the dangerous direction. :

[0126] ;

[0127] After the above symbol processing, regardless of whether an increase or decrease in the measured environmental parameter indicates danger, the rate of change along the danger direction will be... All values ​​were positive.

[0128] The non-volatile memory of the processing unit pre-stores the over-limit alarm threshold and rate of change threshold corresponding to the type of environmental parameter being measured. Threshold for the number of times the continuous rate of change exceeds the limit and the hazard direction coefficient .

[0129] For upper limit type parameters where an increase in the measured value indicates an increased level of danger, configure an upper limit alarm threshold. For lower limit parameters where a decrease in the measured value indicates an increase in the degree of danger, a lower limit alarm threshold should be configured. For the same environmental parameter under test, configure the corresponding upper or lower alarm threshold according to its alarm type.

[0130] Rate of change threshold A positive value can be determined based on the sensor's measurement accuracy, the range of change rate under normal operating conditions, and the range of change rate from abnormal operating condition tests or historical monitoring data. Threshold for the number of consecutive rate of change exceeding the limit. It is a positive integer, and in one specific implementation, its value can be from 3 to 5.

[0131] The processing unit first determines whether the measured value of the current environmental parameter reaches the corresponding over-limit alarm threshold, and then determines whether the rate of change of the dangerous direction over multiple consecutive sampling periods reaches the rate of change threshold. The determination of the over-limit alarm state takes precedence over the trend warning state.

[0132] For upper limit type parameters, the processing unit determines that the sensor node enters the over-limit alarm state when the following conditions are met:

[0133] ;

[0134] For lower limit parameters, the processing unit determines that the sensor node enters an over-limit alarm state when the following conditions are met:

[0135] ;

[0136] When the measured value of the current environmental parameter has not yet reached the corresponding over-limit alarm threshold, the processing unit further determines the most recent continuous Whether the rate of change of the danger direction in each sampling period reaches or exceeds the rate of change threshold. .

[0137] For upper limit type parameters, the criteria for determining the trend warning status are:

[0138] ;

[0139] ;

[0140] For lower limit parameters, the criteria for determining the trend warning status are:

[0141] ;

[0142] ;

[0143] When the corresponding type of non-boundary condition is met, and the above The rate of change for each dangerous direction has reached or exceeded the rate of change threshold. At that time, the processing unit sets the node status to trend warning status.

[0144] When the measured value of the environmental parameter under test has not yet reached the over-limit alarm threshold, but the continuous rate of change condition is not met, the processing unit does not enter the trend warning state. This avoids directly judging an occasional increase in the rate of change within a single sampling period as a continuous abnormal trend.

[0145] When the measured value of the environmental parameter reaches the corresponding over-limit alarm threshold, the processing unit no longer uses the continuous rate of change condition as a prerequisite for entering the alarm state, but directly sets the node state to the over-limit alarm state. The processing unit updates the local node state flag according to the above determination result. The node state includes at least the normal state, the trend warning state, and the over-limit alarm state. After the node state changes, the processing unit controls the first communication unit to generate and send the corresponding node state message; when the node enters the trend warning state or the over-limit alarm state, it also triggers the subsequent directed cascading wake-up process.

[0146] See attached document Figure 5 This embodiment further illustrates the process of generating a directional cascaded wake-up frame, calculating the wake-up delay time, and hop-by-hop waking up downstream associated nodes after a sensor node enters a trend warning state or an over-limit alarm state.

[0147] When the processing unit of a sensor node determines that the node has entered a trend warning state or an over-limit alarm state, it identifies the node as the event source node for the corresponding abnormal event. The processing unit controls the first communication unit to prioritize sending node status messages and directional cascading wake-up frames.

[0148] Node status messages are used to report the current status information of the node to the edge gateway, while directional concatenated wake-up frames are used to notify downstream associated nodes in the propagation direction to adjust their sampling periods in advance. Complete measurement data is not carried in directional concatenated wake-up frames, but is cached by the sensor node in its local storage area and sent to the edge gateway in batches according to preset data reporting time slots, polling requests from the edge gateway, or network idle indications.

[0149] The processing unit generates directional cascaded wake-up control information and encapsulates it in the payload of the directional cascaded wake-up frame. The directional cascaded wake-up control information includes at least an event identifier field, an event source node identifier field, an event source status code field, a topology direction identifier field, at least one wake-up entry for the target node in this hop, a frame sequence number field, a hop count limit field, and an event hold duration field.

[0150] Each local hop target node wake-up entry includes a local hop target node identifier and a wake-up delay time corresponding to that local hop target node. The local hop target node is the downstream target node determined by the current sending node from its downstream topology associated node set, and is the direct receiving object of the current one-hop directional concatenated wake-up frame.

[0151] A directional cascading wake-up frame can include one or more local hop target node wake-up entries to notify downstream target nodes located in different roadway branches or different propagation directions. Other downstream associated nodes that are not identified as direct receivers of the current hop are not local hop target nodes of the current hop.

[0152] The event source node identifier indicates the sensor node that first detected the corresponding abnormal state and generated the abnormal event. The event source node identifier remains unchanged during hop-by-hop forwarding of the same abnormal event. The sensor node currently sending the directed concatenated wake-up frame is identified by the source address field of the communication frame's Media Access Control layer, thus distinguishing the event source node from the current forwarding node.

[0153] The event source status code indicates whether the event source node is in a trend warning state or an over-limit alarm state when generating an abnormal event. The self-test fault status of the sensing device is reported to the edge gateway through the node status message and is not used as the event source status for targeted cascading wake-up along the parameter propagation path of the tested environment.

[0154] Event identifiers are used to distinguish different abnormal events. An event source node generates a corresponding event identifier when it first enters a trend warning state or an over-limit alarm state. The event identifier is formed by combining the event source node's node network identifier and its local event count value.

[0155] The local event count is incremented before a new event is generated and written to non-volatile memory, enabling the sensor node to continue generating event identifiers based on the previous count after restarting. The node network identifier of the event source node and the local event count work together to reduce the possibility of duplicate event identifiers generated by different nodes or at different times.

[0156] The frame sequence number is used to identify directed concatenated wake-up frames repeatedly sent by the same sending node in the same abnormal event. The event source node and each forwarding node maintain a local sent frame sequence number for each valid event; when the corresponding node generates a new directed concatenated wake-up frame for the same event, it increments the corresponding local sent frame sequence number.

[0157] The hop count limit field limits the maximum number of hops a directional cascaded wake-up frame can continue to be forwarded. When the hop count limit parameter is zero, the receiving node still executes the wake-up delay timing and sampling period switching corresponding to its own node, but no longer forwards the directional cascaded wake-up frame to the next hop associated node.

[0158] The event retention duration limits the maximum time a receiving node can store the corresponding event record and maintain the event processing state. The event retention duration begins when the receiving node first completely parses the directional cascading wake-up control information for the corresponding event.

[0159] Topology direction identifiers are used to define the propagation direction of the directional cascaded wake-up frame. As one specific implementation, the topology direction identifier can be a directed topology edge identifier; when encoding using direction types such as downwind, upwind, or roadway branch direction, it should also be combined with the corresponding roadway branch identifier so that the receiving node can determine the corresponding next-hop associated node.

[0160] The topology direction identifier does not directly list specific receiving nodes. The direct receiving target of the current directional cascaded wake-up frame is determined by the local target node identifier in the wake-up entry of each local target node.

[0161] The processing unit of the event source node reads the locally stored set of downstream topology associated nodes and determines one or more downstream associated nodes set along the corresponding propagation direction. For the current node... any downstream associated node The processing unit calculates the wake-up delay time based on the physical distance between nodes, the equivalent propagation velocity of the corresponding roadway segment, and the early wake-up margin coefficient. :

[0162] ;

[0163] in, Indicates the current node downstream related nodes The physical distance between them; Indicates the current node downstream related nodes Lane section markings between; Indicates the identification of lane section markers Equivalent propagation speed of a segment that matches the type of environmental parameters being measured; This represents the early wake-up margin coefficient.

[0164] Early Awakening Margin Greater than zero and less than 1. As one specific implementation method, The value ranges from 0.5 to 0.8. Therefore, the wake-up delay time calculated according to the above formula is shorter than the propagation time calculated with the same physical distance and equivalent propagation speed of the segment.

[0165] The processing unit reads the roadway section identifier from the local speed parameter table. The equivalent propagation speed of the segment corresponding to the parameter type of the measured environment. When the corresponding speed parameter does not exist, expires, or fails verification, the processing unit uses the locally pre-stored conservative upper limit propagation speed. The equivalent propagation speed of the replacement segment is used in the calculation.

[0166] Conservative upper limit of propagation speed The propagation speed should not be less than the maximum equivalent propagation speed that the corresponding environmental parameter under test is expected to reach within the corresponding roadway section. When using a conservative upper limit propagation speed for calculation, the resulting wake-up delay time will not be later than the time calculated based on the expected maximum equivalent propagation speed.

[0167] The aforementioned wake-up delay time represents the local relative time during which the receiving node waits to switch to the high-frequency sampling period after fully parsing the current one-hop directional cascade wake-up control information. Each forwarding node calculates its corresponding wake-up delay time based on the physical distance between itself and its next-hop associated node. This time does not represent the cumulative propagation time of abnormal environmental parameters from the event source node to a downstream node.

[0168] After the processing unit completes the generation of the directional cascaded wake-up control information, it controls the first communication unit to switch to the preset wireless control channel and sets a long preamble sequence in the frame header of the directional cascaded wake-up frame.

[0169] In a wireless sensor network, each sensor node operates independently according to its own basic sleep / wake cycle, and the sleep / wake phases of each node are not required to maintain global synchronization. A long preamble sequence is used to enable downstream associated nodes at different sleep / wake phases to detect the presence of a directional cascaded wake-up frame to be received on the current control channel when periodically opening the receive window.

[0170] The duration of a long preamble sequence is denoted as The basic sleep-wake cycle is denoted as... The time required for the RF receiving circuit to enter a stable receiving state from startup is denoted as . The duration of the channel detection window is denoted as In one specific implementation, the duration of the long preamble sequence satisfies:

[0171] ;

[0172] Setting the long preamble sequence according to the aforementioned duration allows downstream associated nodes time to complete RF receiver circuit startup and channel detection after opening the receive window within a basic sleep-wake cycle. When each downstream associated node forwards the directional concatenated wake-up frame hop-by-hop, it resets the long preamble sequence that meets the above conditions in the newly generated directional concatenated wake-up frame.

[0173] Downstream associated nodes periodically open their receiving windows according to their basic sleep-wake cycle and detect the radio frequency energy of the radio control channel within the receiving window. When the channel detection result reaches a preset energy threshold and the duration reaches a preset detection duration, the first communication unit pauses and enters a sleep state, while keeping the radio frequency receiving circuit in a receiving state to continue receiving the frame header and payload following the long preamble sequence.

[0174] To prevent interference signals from causing the RF receiving circuit to remain on, the first communication unit can also set a frame reception timeout. If a valid frame is not received within the frame reception timeout period, or if frame verification fails, the processing unit ends the current reception and resumes operation according to the original sleep-wake schedule.

[0175] After the downstream associated node fully receives the directional cascaded wake-up frame, the processing unit parses the event identifier, topology direction identifier, and wake-up entries of each local hop target node, and compares the node network identifier of this node with the identifiers of each local hop target node.

[0176] When the node network identifier of this node does not match any of the identifiers of the target nodes in this hop, the processing unit discards the directional cascaded wake-up frame and controls the first communication unit to restore the original sleep wake-up schedule.

[0177] When the node network identifier of this node matches one of the local target node identifiers, the processing unit reads the wake-up delay time in the wake-up entry of the corresponding local target node and queries the local processed event cache.

[0178] The processed event buffer records at least the event identifier, the previous hop node identifier, the maximum sequence number of frames processed, the event hold duration, the first reception time, and the event release status. The previous hop node identifier is determined based on the Media Access Control layer source address of the received directed cascading wake-up frame.

[0179] When the event identifier and the previous hop node identifier of the received directional cascade wake-up frame are the same as the records in the processed event buffer, and the frame sequence number is not greater than the corresponding maximum processed frame sequence number, the processing unit determines the frame as a duplicate frame and will not restart the timer or continue forwarding.

[0180] When the event identifier does not exist in the processed event cache, or when the event identifier is the same as the previous hop node identifier but the frame sequence number is greater than the maximum processed frame sequence number, the processing unit determines the frame as a valid frame and establishes or updates the corresponding event record.

[0181] For a valid frame, the processing unit reads the locally stored set of downstream topology associated nodes and determines the next-hop associated node that is downstream of the current node in the direction of propagation of the measured environment parameters, based on the topology direction identifier. The processing unit reads the physical distance and road segment identifier between the current node and each next-hop associated node, and calculates the wake-up delay time corresponding to each next-hop associated node.

[0182] The processing unit generates next-hop directional cascading wake-up control information. The next-hop directional cascading wake-up control information inherits the event identifier, event source node identifier, event source status code, topology direction identifier, and event hold duration of the current event, resets the wake-up entry of the target node for this hop, and adopts the local transmission frame sequence number maintained by the current forwarding node for this event.

[0183] When the hop count limit parameter in the current frame is greater than zero, the processing unit decrements the hop count limit parameter by one and writes the reduced value into the next-hop directional cascading wake-up control information. When the reduced hop count limit parameter is zero, the next-hop associated node receives the frame and performs local wake-up scheduling, but no longer forwards it.

[0184] The processing unit controls the first communication unit to set a long preamble sequence in the next-hop directional concatenated wake-up frame and broadcasts the directional concatenated wake-up frame to the next-hop associated node. When the local remaining waiting time of this node expires, the processing unit controls the first communication unit to send the next-hop directional concatenated wake-up frame to the next-hop associated node.

[0185] The sending of the next-hop directional cascade wake-up frame can be performed synchronously with the local node switching to high-frequency sampling state, or it can be performed within a preset short period of time before the switching operation, but hop-by-hop forwarding should not be completed in advance before the remaining local waiting time expires.

[0186] By executing the next-hop forwarding when the segment waiting time of each node expires, the timing start point of the next level node can be shifted backward in sequence, thereby forming a tiered wake-up sequence corresponding to the process of abnormal environmental parameters propagating segment by segment along the roadway.

[0187] Downstream associated nodes use the moment when they fully receive and parse the directional cascade wake-up control information as their local timing start point. Considering that long preamble reception, frame transmission, and message parsing have already taken up a certain amount of time, the processing unit deducts a preset communication processing delay compensation value from the corresponding wake-up delay time. Get the remaining local waiting time :

[0188] ;

[0189] Communication processing delay compensation value The time is determined based on the long preamble reception time, the directional cascaded wake-up frame transmission time, and the maximum preset parsing time of the processing unit. Setting the time limit to be no less than the estimated time limit for the communication and parsing process described above can prevent nodes from delaying the switching of the sampling period due to the time consumed by communication and parsing.

[0190] When the local remaining waiting time When the timeout is zero, the processing unit immediately switches the node to high-frequency sampling state; when the remaining local waiting time is greater than zero, the processing unit starts the local timer and switches to high-frequency sampling state after the timer expires.

[0191] The high-frequency sampling period in high-frequency sampling mode is denoted as It is determined by the following formula:

[0192] ;

[0193] in, This is the sampling frequency multiplication factor, and it is a positive integer greater than 1. As one specific implementation method, The value ranges from 2 to 4. Therefore, the high-frequency sampling period... Less than the basic sleep-wake cycle .

[0194] When the same sensor node receives valid directional cascaded wake-up frames corresponding to multiple different event identifiers, the processing unit saves the event identifier, event hold duration, first reception time, local remaining waiting time, and event release status for each event.

[0195] The processing unit compares the remaining local waiting time corresponding to each unresolved event and determines the moment when the node enters the high-frequency sampling state based on the minimum value among them. After the node enters the high-frequency sampling state, as long as there is still at least one valid event that has not been resolved, the processing unit maintains the high-frequency sampling cycle and does not immediately resume the basic sleep-wake cycle because one of the events has been resolved.

[0196] For each event, the processing unit clears the local event record corresponding to that event when both of the following conditions are met:

[0197] First, the sensor node has received the event cancellation signal sent by the edge gateway, which contains the corresponding event identifier, or the event holding time has been reached since the node first completely parsed the directional cascading wake-up control information of the corresponding event.

[0198] Second, sensor nodes are continuous. Each high-frequency sampling cycle detected that the measured values ​​of the environmental parameters under test were within the preset recovery range, and the rate of change in the dangerous direction was within the preset recovery range. Below the preset recovery rate threshold .in, The threshold for the number of consecutive recoveries. The rate of change threshold used for trend warning determination is less than or equal to .

[0199] After all locally stored event records are cleared, the processing unit will change the sampling period of this node from the high-frequency sampling period. Restore to basic hibernation-wake cycle .

[0200] See attached document Figure 6 This embodiment further illustrates the process by which the edge gateway receives directional concatenated wake-up frames and node status messages, establishes an event path node set, generates uplink bit-field encoded status frames, and caches and transmits complete measurement data back.

[0201] The edge gateway's listening unit operates in promiscuous reception mode to monitor directional cascaded wake-up frames transmitted by various sensor nodes within the wireless control channel. Promiscuous reception mode enables the listening unit to receive wireless communication frames whose destination address does not point to the edge gateway, but which can be correctly demodulated by the edge gateway.

[0202] The monitoring unit also detects long preamble sequences in the radio control channel. The duration of long preamble identification is denoted as... The maximum duration of the preamble used in a normal communication frame is denoted as . The duration of the long preamble of the directional cascaded wake-up frame is denoted as . The long preamble recognition time must satisfy:

[0203] ;

[0204] When the monitoring unit continuously detects a signal that conforms to the preset preamble modulation characteristics, and the duration of the signal reaches... At this time, the listening unit generates a frame reception notification and continues to receive the frame header and payload following the long preamble sequence. The frame reception notification can be sent to the reassembly unit in the form of a hardware interrupt or a software event.

[0205] After receiving a frame, the monitoring unit performs frame type verification and integrity verification on the received frame. Frame type verification is used to determine whether the received frame is a directed cascading wake-up frame, and integrity verification can use cyclic redundancy check. Frames that fail the verification do not participate in the establishment of subsequent event node sets.

[0206] When the payload of the directional cascaded wake-up frame is transmitted in encrypted form, the reassembly unit calls the network shared key corresponding to the corresponding sensor node or node group to decrypt the payload; when the payload is not encrypted, the reassembly unit directly parses the payload. The network shared key is written to the edge gateway and the corresponding sensor node during the network initialization phase and selected according to the preset key identifier.

[0207] The reassembly unit extracts the event identifier, event source node identifier, event source status code, topology direction identifier, target node identifier for this hop, frame sequence number, hop count limit parameter, and event hold duration from the directional cascade wake-up control information.

[0208] The edge gateway categorizes received directed concatenated wake-up frames according to their event identifiers and identifies duplicate frames based on their frame sequence number and the node network identifier of the sending node. For valid directed concatenated wake-up frames belonging to the same event identifier, the reassembly unit records the event source node and the target nodes for each hop listed in the directed concatenated wake-up frames, and establishes or updates the corresponding event path node set accordingly.

[0209] The event path node set includes at least the event source node and the target nodes for each hop that have been explicitly specified by the directional concatenated wake-up frame. When the edge gateway has not yet received the next-hop directional concatenated wake-up frame, it does not directly add unacknowledged downstream nodes to the event path node set. As the hop-by-hop forwarding process continues, the reassembly unit updates the event path node set incrementally based on subsequently received directional concatenated wake-up frames.

[0210] When multiple valid exception events exist within the same data frame generation period, the reassembly unit maintains an event identifier, event source node, event path node set, and current event state for each exception event, and generates a corresponding uplink bit-field encoded status frame. Each uplink bit-field encoded status frame corresponds to only one event identifier.

[0211] When the same sensor node belongs to the event path node set of multiple abnormal events, the state bit field of the sensor node can be written into the uplink bit field encoded state frame corresponding to each abnormal event. The node state encoding and event cancellation processing between each abnormal event are independent of each other.

[0212] The second communication unit receives node status messages periodically sent by each sensor node or triggered by events. Each node status message includes at least the node network identifier, event identifier, current status code, status sampling time, and message sequence number. When a node status does not correspond to a specific abnormal event, the event identifier field is filled with a preset empty value.

[0213] Under normal sampling conditions, the sending period of node status messages is denoted as: In high-frequency sampling mode, the sending period of node status messages is denoted as... .in, Not greater than the basic sleep-wake cycle Preset integer multiples, Not greater than the high-frequency sampling period The preset integer multiple.

[0214] The edge gateway sets corresponding communication timeout times for different sampling states. The communication timeout period meets the following requirements:

[0215] ;

[0216] in, Indicates the node status message transmission period under the corresponding sampling state; This indicates the time required to complete at least one message retransmission and corresponding channel backoff; This represents the time reserved for clock errors and wireless transmission fluctuations. Therefore, the edge gateway will not immediately classify a sensor node as offline based solely on the loss of a single node's status message.

[0217] The reassembly unit establishes or updates the local node status table based on the node status message verified by the message sequence number. The node status table records at least the node network identifier, the most recent valid status code, the associated event identifier, the most recent status sampling time, the most recent message reception time, the most recent message sequence number, and the communication connection status.

[0218] For duplicate messages whose sequence number is not greater than the sequence number already recorded in the node status table, the reassembly unit does not use the message to overwrite the newer node status record. In cases where the message sequence number wraps around, the reassembly unit determines the relationship between the old and new messages according to a preset cyclic sequence number comparison rule.

[0219] When a node status message indicates a self-test failure of the sensing device, or when the edge gateway determines that the sensor node is offline based on the communication timeout, and there is currently no valid event identifier corresponding to the node's abnormality, the edge gateway generates a node device abnormal event identifier.

[0220] The node device abnormal event identifier is formed by combining the edge gateway network identifier, the abnormal node network identifier, the abnormality type identifier, and the edge gateway-side event count value. The edge gateway-side event count value is incremented and written to non-volatile memory before a new node device abnormal event is generated.

[0221] The edge gateway writes the node device abnormal event identifier into the corresponding node status record and generates an uplink bit-field encoded status frame for the node device abnormal event. For node device abnormal events involving only a single abnormal node, its event path node set must include at least the abnormal node; when the topology linkage configuration also specifies associated nodes that need to be monitored together, the associated nodes can also be added to the corresponding event path node set.

[0222] For each valid event, the edge gateway records the event source node, the set of event path nodes, the event status, and the continuous recovery count. Within each node status message update cycle, the edge gateway checks the current status of the event source node and all event path nodes.

[0223] When the edge gateway is continuous If, during each inspection cycle, the event source node and all event path nodes are confirmed to be free from trend warning, over-limit alarm, sensor self-test fault, or node offline status, the event is deemed to meet the release conditions.

[0224] The edge gateway generates an event cancellation signal containing the corresponding event identifier and cancellation status code, and sends it to the relevant sensor nodes according to the propagation path corresponding to the event. For abnormal events of node devices, the continuous recovery count value will only begin to accumulate after the abnormal node comes back online or its self-test status returns to normal.

[0225] The reassembly unit performs categorized variable-length bit-field encoding on the status of each sensor node based on the event path node set and the local node status table, and generates uplink bit-field encoded status frames.

[0226] For non-event nodes that do not belong to the current event path node set, the reassembly unit allocates a 1-bit status field. This status bit is used to indicate the communication connection status of the node, where a status bit of 1 indicates that the node is online, and a status bit of 0 indicates that the node is offline or that the node status message has exceeded the communication timeout period.

[0227] For each event path node belonging to the current event path node set, the reassembly unit allocates a 3-bit status field. The 3-bit status field includes a 1-bit communication connection status bit and a 2-bit environment status code bit.

[0228] The 3-bit status field of the event path node includes a 1-bit communication connection status bit and a 2-bit environment status encoding bit, and their encoding correspondence is shown in Table 1.

[0229] Table 1. Correspondence between the status bit field encodings of event path nodes:

[0230] 1 00 100 The measured environmental parameters are normal. 1 01 101 Trend warning status 1 10 110 Over-limit alarm status 1 11 111 Sensor self-test fault status 0 0 000 Node offline or status message timed out

[0231] When the communication connection status bit is 0, the environmental status code bit is used as an invalid placeholder field, and the central controller does not determine the status of the measured environmental parameter based on this environmental status code bit. Other environmental status code values ​​besides 00 can be reserved as reserved codes when the communication connection status bit is 0, but the transmitting end preferably sets them to 00.

[0232] When an event path node reports a sensor self-test fault and is still able to communicate with the edge gateway, the reassembly unit sets the communication connection status bit to 1 and the environment status code bit to 11. When the event path node exceeds the communication timeout period, the reassembly unit sets the communication connection status bit to 0 and the environment status code bit to 00.

[0233] The reassembly unit determines the arrangement position of each node's state bit field in the payload of the uplink bit field encoded state frame according to the preset state bit field arrangement rules.

[0234] Under normal operating conditions where there are no valid abnormal events, the edge gateway can arrange the status bit fields of each sensor node in ascending order according to the node network identifier and generate a normal status frame using a preset fixed layout.

[0235] When a valid abnormal event exists, the reorganization unit first arranges the node status bit fields in the corresponding event path node set, and then arranges the status bit fields of non-event nodes. The event path node status bit fields are written into the event path node status area at the start of the payload, and the non-event node status bit fields are written into the subsequent non-event node status areas.

[0236] For the same abnormal event, the event source node is listed first in the event path node status area. Apart from the event source node, the remaining event path nodes are arranged in ascending order of the cumulative directed path distance from the event source node to the corresponding node. If the cumulative directed path distances are the same, they are arranged in ascending order of node network identifier.

[0237] From event source node to event path node Cumulative directed path distance Determined by the sum of the physical distances between adjacent nodes along the event propagation path:

[0238] ;

[0239] in, This indicates the path from the event source node to the event path node. The directed propagation path, Indicates adjacent nodes in the path With nodes The physical distance between them. In the case of multiple directed propagation paths, the cumulative directed path distance is determined by the actual path traversed by the directional cascaded wake-up frames.

[0240] Non-event nodes are arranged in ascending order according to their node network identifiers, and the corresponding 1-bit communication connection status bit is written into the non-event node status area in sequence.

[0241] The frame header control field of the uplink bit-field encoded status frame includes at least the bit sequence mode flag, event identifier, frame layout sequence number, bit field mapping version number, data frame sequence number, and payload length.

[0242] The bit sequence mode flag indicates whether the current data frame uses a fixed node layout or a dynamic node layout. The frame layout sequence number identifies the event path node set and its order for the current abnormal event; when the event path node set or the node order changes, the edge gateway updates the frame layout sequence number.

[0243] The bit-field mapping version number is used to identify the specific encoding and bit-field offset configuration corresponding to the current frame layout. The edge gateway updates the bit-field mapping version number when the node encoding type, bit-field length, or bit-field start offset changes. The same frame layout sequence number can correspond to multiple revised bit-field mapping versions.

[0244] Before sending the first uplink bit-field encoded status frame with a new frame layout sequence number or a new bit-field mapping version number, the edge gateway generates a corresponding bit-field mapping table update message and sends it to the central controller.

[0245] Each bit field mapping table corresponds to at least one event identifier, one frame layout sequence number, and one bit field mapping version number. A bit field mapping table update message includes at least:

[0246] The frame layout sequence number, bit field mapping version number, total number of nodes in the data frame, node network identifier of each node, node arrangement order, encoding type, state bit field start offset, state bit field length, and the attribute of each node belonging to an event path node or a non-event node.

[0247] After receiving the bit-field mapping table confirmation message returned by the central controller, the edge gateway begins to send uplink bit-field encoded status frames using the corresponding frame layout sequence number and bit-field mapping version number.

[0248] Before the new bit-field mapping table is confirmed, the edge gateway sends an emergency status frame using a preset fixed field format. The emergency status frame includes at least an event identifier, node network identifier, communication connection status, environment status, data frame sequence number, and a checksum field.

[0249] The fixed field format does not rely on a dynamic bit-field mapping table, and the central controller can directly parse it according to the preset field offset. When using this fixed field format, the edge gateway prioritizes sending the status of nodes in over-limit alarm states and other nodes that require immediate security linkage.

[0250] If the edge gateway does not receive a bit-field mapping table acknowledgment message within a preset acknowledgment time, it retransmits a bit-field mapping table update message. After reaching the preset maximum number of retransmissions, the edge gateway continues to send status data using a fixed field format and reports the bit-field mapping table synchronization failure status to the central controller.

[0251] The Ethernet unit receives the uplink bit-field encoded status frame or emergency status frame generated by the reassembly unit and sends it to the central controller through the industrial Ethernet backbone network.

[0252] The complete measurement data collected by the sensor node is not written into the uplink bit-field encoded status frame sent in real time. Instead, the sensor node encapsulates the complete measurement data into a measurement data message that is independent of the node status message, and sends it to the edge gateway according to the edge gateway polling request, the preset batch reporting time slot, or the network idle indication.

[0253] When a sensor node is in high-frequency sampling mode, it continues to save the complete measurement data generated by high-frequency sampling. The measurement data message includes at least the node network identifier, the type of the measured environmental parameter, the sampling time, the data sequence number, the measured value, and the data verification field.

[0254] After receiving the measurement data packet, the edge gateway writes the complete measurement data into a local circular buffer stored in non-volatile memory. The local circular buffer stores the measurement data of each sensor node according to the sampling time or data sequence number.

[0255] When the local circular buffer reaches its storage capacity limit, the edge gateway overwrites the earliest measurement data that has not yet been transmitted back, in chronological order, and records the data overwrite flag, the node network identifier of the overwritten data, and the time range. The edge gateway then reports this data overwrite information along with subsequent data transmissions to the central controller.

[0256] The edge gateway monitors the link utilization of the industrial Ethernet backbone network. When the link utilization is lower than a preset load threshold, or when the edge gateway receives a historical data upload request from the central controller, it reads complete measurement data that has not yet been transmitted back from its local circular buffer.

[0257] The edge gateway encapsulates the complete measurement data it reads into independent historical measurement data packets and sends them to the central controller via the industrial Ethernet backbone network. The historical measurement data packet includes at least the node network identifier, the type of the measured environmental parameter, the start sampling time, the end sampling time, the data sequence number range, the measurement data sequence, and a data verification field.

[0258] After the central controller confirms successful reception of historical measurement data packets, the edge gateway marks the corresponding data as transmitted back. For data that has not received confirmation, the edge gateway retransmits it according to a preset number of retransmissions, and retains the corresponding data transmission failure record after reaching the maximum number of retransmissions.

[0259] See attached document Figure 7 This embodiment further illustrates the closed-loop linkage control process in which the central controller parses the node status, detects changes in the node status, generates action commands, and confirms the action results based on the actuator feedback.

[0260] The central controller's network interface receives uplink bit-field encoded status frames, emergency status frames, and bit-field mapping table update messages sent by the edge gateway. As a specific implementation, the network interface uses direct memory access to write the received data frames into a circular receive buffer in system memory, reducing the time spent by the processor performing data transfer.

[0261] Each frame record in the circular receive buffer includes at least the data frame content, reception time, transmitting edge gateway identifier, data frame type, and data frame sequence number. The logic unit reads the data frames in the reception order and first performs frame type, payload length, data frame sequence number, and data integrity checks.

[0262] When the circular receive buffer reaches its capacity limit, the central controller prioritizes retaining emergency status frames and the latest unprocessed status frames, clears historical status frames that have been confirmed as duplicate frames, and generates a receive buffer overflow record. Thus, the circular receive buffer is used to reduce the possibility of consecutive status frames overwriting unparsed data, but it is not stated that data loss will not occur under any communication load.

[0263] The logic unit reads the bit sequence mode flag, event identifier, frame layout sequence number, bit field mapping version number, data frame sequence number, and payload length from the control field of the uplink bit field encoded status frame header.

[0264] When the bit sequence mode flag indicates that the current data frame adopts dynamic node layout, the logic unit searches for a matching bit field mapping table in the local bit field mapping table storage area based on the event identifier, frame layout sequence number and bit field mapping version number.

[0265] The bit-field mapping table records at least the node network identifier, node arrangement order, encoding type, state bit field start offset, state bit field length, and whether the node belongs to an event path node or a non-event node for each node.

[0266] When the central controller has not yet saved a matching bit field mapping table, the logic unit temporarily stores the current data frame in the parsing buffer and sends a bit field mapping table retransmission request to the edge gateway. Before obtaining the corresponding bit field mapping table, the logic unit does not parse the data frame according to the unknown state bit field arrangement, nor does it generate action instructions based on the data frame.

[0267] The buffer to be parsed has a preset waiting time for each frame. After the central controller obtains the corresponding bit field mapping table within the preset waiting time, it re-parses the corresponding data frame; if the bit field mapping table is not obtained after the preset waiting time, the logic unit clears the data frame to be parsed and generates a bit field mapping table missing status record.

[0268] When the received data frame is an emergency status frame using a preset fixed field format, the logic unit does not rely on the dynamic bit field mapping table, but directly parses the event identifier, node network identifier, communication connection status, environment status and data frame sequence number according to the preset field offset.

[0269] When an emergency status frame indicates that the corresponding node is in an over-limit alarm state, or in a self-test fault state of a sensor device that is pre-configured in the topology linkage mapping table to perform safety linkage, or in an offline state, the logic unit directly generates the corresponding status trigger signal.

[0270] For uplink bit-field encoded state frames that pass verification and for which the corresponding bit-field mapping table can be obtained, the logic unit determines the position of each node's state bit field in the payload according to the bit-field mapping table, and converts the parsing result into a unified node state table.

[0271] A unified node status table can be implemented using a two-dimensional array or a structured record set. Each row corresponds to a sensor node, and each status field records the event identifier, node network identifier, communication connection status, environmental status, topology location information, status sampling time, and data validity flag.

[0272] For non-event nodes using a 1-bit status field, the logic unit maps this status bit to the communication connection status field and sets the environment status field to the non-event node uncoded state. The non-event node uncoded state indicates that the current data frame does not provide the environment status of the node, but does not necessarily mean that the measured environment parameters of the node are normal.

[0273] For an event path node that uses a 3-bit status bit field, the logic unit maps the first bit to the communication connection status field and maps the remaining 2 bits to the environment status field according to the aforementioned event path node status bit field encoding correspondence.

[0274] When the communication connection status bit is 0, the logic unit sets the node to offline or status message timeout status and sets the environment status field to invalid status, without judging the status of the tested environment parameters of the node based on the subsequent 2-bit environment status encoding.

[0275] In the case of multiple roadway branch nodes at the same topological level, each sensor node corresponds to an independent record in a unified node status table, and its roadway segment, topological branch, and relationship with adjacent nodes are determined by the node network identifier and topological location information.

[0276] For each event identifier, the logic unit stores the unified node status table for the current communication cycle and the unified node status table for the previous valid communication cycle. When two consecutive communication cycles use different frame layout sequence numbers or bit field mapping version numbers, the logic unit performs parsing according to its respective bit field mapping table, and then aligns the two unified node status tables using the node network identifier as an index.

[0277] For a newly added node record in the current cycle, the logic unit sets the node's state in the previous cycle to an unknown state. For a node record that existed in the previous cycle but failed to be parsed correctly in the current data frame, the logic unit sets its current state to an unknown state. A node is only set to an offline state when the communication connection status bit explicitly indicates offline, or when the node exceeds a preset communication timeout.

[0278] The logic unit compares the communication connection state and environment state of the same node in two adjacent valid communication cycles and generates a state difference table. For any node i, its state change flag... It can be represented as:

[0279] ;

[0280] in, This indicates the communication connection status of node i in the current communication cycle. This indicates the environmental state of node i in the current communication cycle.

[0281] As a specific implementation, the logic unit can first convert the node states of the current cycle and the previous cycle into state codes of the same fixed width, and then perform a bitwise XOR operation on the fixed-width state codes of the same node. The XOR result is used to determine whether the state field of the node has changed.

[0282] The logic unit does not directly perform an XOR operation on the original variable-length state bit string that has not been parsed by the bit field mapping table, nor does it treat different bit changes in the same node state encoding as multiple independent node state changes.

[0283] When a non-event node enters the event path node set in the current cycle, the logic unit sets the environmental state of the node in the previous cycle to the uncoded state of a non-event node, and then compares it with the actual environmental state in the current cycle. When an event path node exits the event path node set in the current cycle, the logic unit retains its communication connection state and sets the current environmental state to the uncoded state of a non-event node.

[0284] The logic unit detects newly occurred dangerous states, changes in danger levels and persistent dangerous states that have not yet completed linkage processing according to the state difference table and the unified node state table of the current cycle.

[0285] Current dangerous states include trend early warning states, over-limit alarm states, as well as self-check fault states of sensing devices or node offline states that are configured in the topological linkage mapping table to require security linkage execution.

[0286] When a node changes from a normal state or the uncoded state of a non-event node to a trend early warning state, an over-limit alarm state, a self-check fault state of a sensing device requiring linkage or an offline state of a node requiring linkage, the logic unit generates a state change trigger signal.

[0287] When a node changes from a trend early warning state to an over-limit alarm state, or from another dangerous state to a state with higher security priority, the logic unit generates a danger level upgrade trigger signal.

[0288] For the first valid status frame received after the central controller is started, the logic unit does not stop processing due to the lack of the state of the previous cycle, but directly checks the dangerous state in the current unified node state table.

[0289] When the data frame of the previous communication cycle is lost, or the node maintains a dangerous state for multiple consecutive communication cycles, as long as the corresponding linkage action has not received an execution success confirmation, the logic unit continues to generate a dangerous state persistence trigger signal.

[0290] Therefore, node state change is used to identify newly occurred events or danger level upgrade events, but it is not the only condition for generating action commands. When the current dangerous state persists and the linkage action has not been completed, subsequent linkage processing can also be triggered.

[0291] The state trigger signals output by the logic unit include at least trigger type, event identifier, node network identifier, current communication connection state of the node, current environmental state of the node, node state of the previous cycle and topology position information. Trigger types include state change trigger, danger level upgrade trigger, dangerous state persistence trigger and unconfirmed linkage action trigger.

[0292] The instruction issuing unit receives the status trigger signal output by the logic unit and queries the pre-stored topology linkage mapping table.

[0293] The topology linkage mapping table records at least the node network identifier or topology area identifier of the triggering node, the trigger status type, the address of the actuator to be controlled, the control command word, the security priority, the action confirmation time, the maximum number of retries, and the backup linkage strategy identifier.

[0294] The actuators to be controlled may include explosion-proof power supply switches, fan control devices, audible and visual alarms, and other underground electrical equipment that establishes a linkage relationship with the corresponding roadway section.

[0295] The instruction issuing unit determines the actuator to be controlled and its control instruction word based on the event identifier, node network identifier, current status and topology location information in the status trigger signal, and generates action instructions.

[0296] An action instruction must include at least an event identifier, a trigger node network identifier, an executor address, a control instruction word, an action instruction sequence number, and a data verification field. The action instruction sequence number is used to uniquely identify a specific instruction transmission process and to match the action result feedback returned by the executor.

[0297] The instruction issuing unit establishes a linkage task record for each group of event identifiers, actuator addresses, and control instruction words. The linkage task record includes at least the current status of the linkage task, the sequence number of the most recent action instruction, the number of times it was sent, the most recent sending time, and the action confirmation status.

[0298] When the same abnormal event generates a state trigger signal targeting the same actuator with the same control command word again, the command issuing unit queries the corresponding linkage task record. If the corresponding action command is waiting for confirmation, or has already received successful action feedback and the actual state of the actuator has not changed, the same action command will not be generated again.

[0299] If no feedback is received after the confirmation time of the previous action command, or if action failure feedback is received, or if the actual state of the actuator is inconsistent with the expected action state, the command issuing unit resends the action command according to the retry rules. Therefore, the action command sequence number is used for feedback matching, and the event identifier, actuator address, and control command word are used to determine whether they belong to the same linkage task.

[0300] When multiple valid events simultaneously impose different control requirements on the same actuator, the command issuing unit compares the safety priorities of each control requirement. Control requirements that cut off power, stop hazardous equipment, activate alarms, or increase safety ventilation capacity take precedence over control requirements that connect power, restore equipment operation, or deactivate alarms.

[0301] When a dangerous event has not been resolved or the corresponding safety action has not been successfully confirmed, the instruction issuing unit will not send a recovery instruction that conflicts with the safety action. For actuators that require manual confirmation before recovery, a recovery action instruction will only be generated after receiving an event resolution signal and manual recovery permission.

[0302] The command issuing unit writes the action command into the corresponding bus transmit register through the fieldbus interface, and the fieldbus controller then sends it to the target actuator. The transmission of this action command does not require periodic polling by the upper-level application of the central controller.

[0303] Fieldbuses can be RS-485 buses, CAN buses, or other industrial communication buses capable of transmitting action commands and action result feedback.

[0304] After receiving an action command, the actuator drives the internal relay, contactor, or control output circuit to change the energized state, operating state, or alarm state of the connected electrical equipment.

[0305] The actuator detects the actual state after the action through relay auxiliary contacts, contactor feedback contacts, equipment operation feedback ports, or the actuator's internal status register, and returns the action result feedback to the central controller.

[0306] The action result feedback should include at least the action command sequence number, actuator address, action execution result, actuator actual status, and actuator fault code. The action execution result should include at least the action success and the target status achieved. When the action execution result is successful and the actuator actual status matches the target status, the central controller will set the corresponding linkage task to the execution completion status.

[0307] When the central controller receives a delayed action result feedback, it matches it to the corresponding historical transmission record based on the action command sequence number. Delayed feedback does not overwrite the status of action commands sent later in the same coordinated task, nor is it used as a basis for canceling subsequent safety actions.

[0308] When the central controller does not receive a successful action feedback within the preset action confirmation time, or receives a failed action feedback, the instruction issuing unit resends the action instruction according to the maximum number of retries configured in the topology linkage mapping table. Each resend is assigned a new action instruction sequence number, and the association between each resend is saved in the linkage task record.

[0309] When an action command fails to receive a successful confirmation after reaching the maximum number of retries, the central controller generates an actuator fault alarm and performs subsequent processing according to the backup linkage strategy recorded in the topology linkage mapping table.

[0310] Backup linkage strategies may include at least one of the following: sending a power-off command to the upper-level explosion-proof power supply switch of the corresponding area, activating a backup audible and visual alarm, sending a safety shutdown command to the adjacent control zone, or reporting the linkage failure status to the duty terminal.

[0311] The central controller forms a closed-loop linkage control from monitoring state input to confirming execution result through the above-mentioned node state analysis, state change detection, action command generation, actuator action, and action result feedback processing.

[0312] Scenario Setting: Assume that the IoT control system of this invention is deployed in the 101 return airway of a coal mine to monitor gas (upper limit parameter, danger direction coefficient). ).

[0313] Node deployment: Node A, Node B, and Node C are deployed sequentially along the windward direction of the tunnel.

[0314] Physical distance: The distance from node A to node B meters, the distance from node B to node C rice.

[0315] See attached document Figure 8 and reference appendix Figure 9 Network and environment parameters:

[0316] Basic sleep-wake cycle Seconds; high-frequency sampling period Seconds (multiplication factor) ).

[0317] The equivalent propagation speed of gas in this section issued by the edge gateway m / s (based on the current wind speed in the tunnel and the propagation correction factor).

[0318] Wake-up delay parameter configuration: Early wake-up margin factor Communication processing delay compensation Second.

[0319] Gas trend warning threshold: rate of change threshold Number of consecutive times exceeding the limit .

[0320] Step 1: Trend Early Warning Judgment (Node A):

[0321] 1. Node A according to Gas concentration is collected every second. , , , At time 1, the filtered measured values ​​were 0.30%, 0.60%, 0.90%, and 1.20% respectively (assuming the over-limit alarm threshold is 15%, and the current limit has not been exceeded).

[0322] 2. Calculate the first-order difference rate of change:

[0323] cycle: ;

[0324] cycle: ;

[0325] cycle: ;

[0326] 3. Because of continuity Rate of change of dangerous direction over a period of time ( All are greater than Node A determines that it has entered the trend warning state, generates an event identifier (Event_01), and serves as the event source node.

[0327] Step 2: Wake-up Delay Calculation and Cascaded Wake-up (Node A → Node B) 1. Node A calculates the wake-up delay time of downstream node B:

[0328] ;

[0329] 2. Node A broadcasts a directional concatenated wake-up frame with a long preamble on the control channel, specifying Node B as the target in the wake-up entry, with a delay of 80 seconds.

[0330] Step 3: Node B receives and timed switching (Node B) Node C):

[0331] 1. Node B receives the wake-up frame, confirms itself as the target node for this hop, and calculates its remaining local waiting time:

[0332] Second

[0333] 2. Node B starts a local timer to maintain the basic low-power mode for 78 seconds. At the end of the 78th second, it automatically switches to... The high-frequency sampling time of seconds perfectly captures the approaching gas wave peak.

[0334] 3. Simultaneously, when node B receives the wake-up frame, it decrements the hop count by one and calculates the wake-up delay of the target node C:

[0335] ;

[0336] And continue to broadcast cascade wake-up frames to node C.

[0337] Step 4: Uplink bit field dynamic encoding (edge ​​gateway):

[0338] The edge gateway listens to the above events and confirms that the "event path node set" contains {A,B,C}, and the non-event nodes are assumed to be {D,E}.

[0339] Packing status frame: A, B, and C are each allocated 3 bits (total 9 bits), and D and E are each allocated 1 bit (total 2 bits).

[0340] Assuming node B is connected (1) and in an early warning state (01), then the 3-bit code of node B is 101.

[0341] This mechanism enables the status frame payload of a tunnel containing 100 nodes to be compressed to within tens of bytes when a local event occurs, achieving extremely low latency transmission to the central controller for coordinated power-off.

[0342] To verify the effectiveness of the present invention, the above-mentioned "physical-communication" collaborative wake-up mechanism was verified by hardware and software in-loop simulation.

[0343] 1. Comparison scheme setup:

[0344] Baseline1 (Fixed Sleep Cycle Method): All nodes remain active throughout the entire process. Seconds, without changing the sampling frequency based on events (traditional low-power WSN solution).

[0345] Baseline2 (Global Concurrent Wake-up Method): Once node A alarms, all nodes in the entire network are immediately woken up via flood broadcast. Seconds (traditional high-security solution).

[0346] The present invention (directional cascaded wake-up method) is based on equivalent propagation speed and physical distance, and performs advance margin timed wake-up along the airflow direction.

[0347] Core experimental indicators

[0348] Peak capture lead time: The time when a node actually starts high-frequency sampling is earlier than the time when the dangerous parameter actually arrives at the physical location of the node.

[0349] Total network power consumption: The total power consumption of the wireless sensor network within 4 hours after the disaster, measured in milliampere-hours (mAh) or joules (J).

[0350] Effect analysis and data evidence:

[0351] Effect 1: Improved accuracy of high-frequency sampling switching (solves the false negative problem in Baseline 1):

[0352] At a wind speed of 2.0 m / s, the time it takes for the gas wave crest to reach node B, which is 200 meters away, is 100 seconds.

[0353] Because Baseline1 maintains a low sampling frequency of 5 seconds, the sampling points are extremely sparse when the concentration changes abruptly. This causes node B to detect the gas over-limit alarm for the first time with an average delay of 3.8 seconds compared to the actual occurrence time.

[0354] This invention employs a feedforward early warning system, with node B switching to high-frequency sampling at 1 second per cycle after 80 seconds. Experimental data shows that the measurement curve of this scheme perfectly matches the actual physical diffusion curve, exhibiting zero lag in capturing dangerous peaks and providing invaluable golden time for coordinated power outages.

[0355] Effect 2: Spatial tiered power consumption characteristics (solving the power consumption pain point of Baseline2):

[0356] In a continuous disaster simulation (lasting 4 hours) in a 1000-meter tunnel (with 10 nodes spaced 100 meters apart):

[0357] Baseline2 (Global Wake-up) caused the 10th node, which is furthest from the source, to start high-frequency sampling and high-frequency communication nearly 10 minutes earlier, resulting in a large amount of ineffective energy consumption and a surge in the total system energy consumption to 4.5 times that of the normal state.

[0358] In this invention, the timer of node 10 is calculated. With a sleep time of up to 400 seconds, it remains in deep sleep for the initial 6 minutes or so. Experimental statistics show that the total network power consumption of this invention is only 32.5% of that of the global wake-up method, and slightly higher than that of the fixed sleep method, achieving the optimal solution between extreme security and extreme low power consumption.

[0359] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An Internet of Things (IoT) control system for a smart mine safety production monitoring device, characterized in that, This includes multiple IoT monitoring nodes deployed within mine roadways; each IoT monitoring node comprises a data acquisition module, a processing module, and a communication module. The acquisition module is used to acquire environmental parameters according to the basic sleep-wake cycle under normal conditions. The processing module is used to, when it is determined that the currently collected environmental parameters meet the preset trend warning conditions, take the current IoT monitoring node as the event source node, determine the theoretical arrival time of the environmental parameters spreading to the downstream target node based on the physical distance between the downstream target node and the event source node, and the equivalent propagation speed of the environmental parameters in the mine roadway, and determine a wake-up delay time less than the theoretical arrival time based on the theoretical arrival time. The communication module is used to send a cascaded wake-up frame containing the wake-up delay time to the downstream target node; The processing module is further configured to, when the current IoT monitoring node, as the downstream target node, receives the cascaded wake-up frame through the communication module, compensate for the communication processing delay caused by receiving and processing the cascaded wake-up frame according to the wake-up delay time, determine the local remaining waiting time, and after the local remaining waiting time has elapsed, control the acquisition module to switch the basic sleep wake-up cycle to a high-frequency sampling cycle to acquire the environmental parameters, so that the current IoT monitoring node switches to the high-frequency sampling cycle before the environmental parameters are expected to arrive; The duration of the high-frequency sampling period is shorter than the duration of the basic sleep-wake period.

2. The IoT control system for the smart mine safety production monitoring equipment according to claim 1, characterized in that, When the processing module determines that the currently collected environmental parameters meet the preset trend warning conditions, the specific operation performed is as follows: The rate of change of the environmental parameters is calculated based on the environmental parameters collected at adjacent sampling times and the time interval between adjacent sampling times; Based on the direction of danger change corresponding to the environmental parameters, the rate of change is reversed to obtain the rate of change of danger direction; Determine whether the rate of change of the dangerous direction for the most recent consecutive preset number of times is greater than or equal to the rate of change threshold; if so, determine that the trend warning condition is met.

3. The IoT control system for the smart mine safety production monitoring equipment according to claim 1, characterized in that, The logic by which the processing module determines the theoretical arrival time and the wake-up delay time is as follows: Dividing the physical distance by the equivalent propagation speed yields the theoretical arrival time of the environmental parameter diffusion to the downstream target node; Multiply the theoretical arrival time by a preset early wake-up margin coefficient to obtain the wake-up delay time; The early wake-up margin coefficient is a value greater than 0 and less than 1.

4. The IoT control system for the smart mine safety production monitoring equipment according to claim 1, characterized in that, The logic by which the processing module compensates for the communication processing delay and determines the remaining local waiting time is as follows: The local remaining waiting time is obtained by subtracting the preset communication processing delay compensation time from the wake-up delay time. Start an internal local timer, and control the acquisition module to continue maintaining the basic sleep-wake cycle during the local timer's countdown. When the local timer reaches the local remaining waiting time, the acquisition module is automatically switched to the high-frequency sampling period; The local remaining waiting time is obtained by subtracting the preset communication processing delay compensation time from the wake-up delay time. When the remaining local waiting time is greater than zero, the internal local timer is started, and during the local timer's counting period, the acquisition module is controlled to continue to maintain the basic sleep-wake cycle. When the local timer reaches the remaining local waiting time, the acquisition module is switched to the high-frequency sampling period. When the local remaining waiting time is equal to zero, the acquisition module is immediately switched to the high-frequency sampling period.

5. The IoT control system for the smart mine safety production monitoring equipment according to claim 1, characterized in that, The processing module is also used to execute cascade forwarding logic: When the cascaded wake-up frame is received, it is determined whether the hop count limit parameter in the cascaded wake-up frame is greater than zero; If the hop count limit parameter is greater than zero, then the next hop associated node is determined from the locally stored set of downstream topology associated nodes, the next hop associated node is determined as the target node of the next hop transmission, and the hop count limit parameter is decremented by one. Based on the physical distance between the current IoT monitoring node and the next-hop associated node, the wake-up delay time corresponding to the next-hop associated node is recalculated, and an updated cascaded wake-up frame is sent to the next-hop associated node through the communication module. The updated cascaded wake-up frame includes the hop count limit parameter reduced by one and the wake-up delay time corresponding to the next-hop associated node. If the hop count limit parameter is equal to zero, the cascade wake-up frame will not be forwarded to the next associated node.

6. The IoT control system for the smart mine safety production monitoring equipment according to claim 1, characterized in that, The cascaded wake-up frame includes an event identifier and at least one wake-up entry for the target node in the local hop. Each wake-up entry for the target node in the local hop includes at least a target node identifier for the local hop and a wake-up delay time corresponding to the target node identifier for the local hop. The processing module is used to extract the event identifier and the local target node identifier in each local target node wake-up entry after receiving the cascaded wake-up frame, and to match and verify the node network identifier of the local node with each local target node identifier respectively. If the node network identifier of this node matches any of the target node identifiers of the current hop, then the wake-up delay time in the wake-up entry of the matched target node is read, the current IoT monitoring node is determined to be the target node of the current hop of the cascade wake-up frame, and the delayed wake-up logic corresponding to the event identifier is executed as the downstream target node.

7. The IoT control system for the smart mine safety production monitoring equipment according to claim 1, characterized in that, It also includes an edge gateway that communicates with each of the IoT monitoring nodes; The edge gateway is used to obtain the current airflow velocity in the mine roadway, calculate the equivalent propagation velocity by combining the propagation correction coefficient corresponding to the environmental parameters, and periodically send it to each of the IoT monitoring nodes for the processing module to call.

8. The IoT control system for the smart mine safety production monitoring equipment according to claim 7, characterized in that, The IoT control system also includes a central controller; The edge gateway further includes a bit-domain dynamic encoding module and an Ethernet unit that is communicatively connected to the bit-domain dynamic encoding module. The bit-domain dynamic encoding module includes a monitoring unit and a reassembly unit. The monitoring unit is used to monitor the wireless control channel, and after detecting the cascaded wake-up frame, it transmits the cascaded wake-up frame to the reassembly unit. The reorganization unit is used to extract the event identifier, the event source node identifier, and the identifiers of each local hop target node from one or more cascaded wake-up frames corresponding to the same event identifier, and to determine the event path node set and non-event path node set corresponding to the event identifier based on the event source node identifier, the identifiers of each local hop target node, and the node status information of each IoT monitoring node. The reassembly unit is further configured to generate an uplink bit-field encoded status frame corresponding to the event identifier, and to allocate a bit-field code of a first length to the nodes in the event path node set, and to allocate a bit-field code of a second length to the nodes in the non-event path node set, wherein the first length is greater than the second length. The Ethernet unit is used to transmit the uplink bit-field encoded status frame generated by the reassembly unit to the central controller.

9. The Internet of Things control system for the smart mine safety production monitoring equipment according to claim 1, characterized in that, The environmental parameter is the methane concentration; The processing module is also used to determine the over-limit hazard level corresponding to the current gas concentration according to at least one of the over-limit amplitude of the current gas concentration exceeding the preset over-limit alarm threshold and the rate of change of the current gas concentration along the direction of concentration increase, in accordance with the preset over-limit hazard level determination rules. Based on the preset mapping relationship between the over-limit danger level and the sampling frequency multiplication factor, the sampling frequency multiplication factor corresponding to the over-limit danger level is determined, and the ratio of the basic sleep-wake cycle to the sampling frequency multiplication factor is determined as the high-frequency sampling cycle. Wherein, the sampling frequency multiplication factor corresponding to the higher limit hazard level is not less than the sampling frequency multiplication factor corresponding to the lower limit hazard level, and the sampling frequency multiplication factor is a positive integer greater than 1.

10. An Internet of Things (IoT) control method for a smart mine safety production monitoring device, used to implement the IoT control system for a smart mine safety production monitoring device as described in any one of claims 1-9, characterized in that, The method includes the following steps: Under normal conditions, multiple IoT monitoring nodes collect environmental parameters according to the basic sleep-wake cycle. When any of the IoT monitoring nodes determines that the currently collected environmental parameters meet the preset trend warning conditions, it will act as the event source node. The event source node determines the theoretical arrival time of the environmental parameters to the downstream target node based on the physical distance between the event source node and the downstream target node, and the equivalent propagation speed of the environmental parameters in the mine roadway, and determines a wake-up delay time that is less than the theoretical arrival time based on the theoretical arrival time. The event source node sends a cascaded wake-up frame containing the wake-up delay time to the downstream target node; The downstream target node receives the cascaded wake-up frame, compensates for the communication processing delay caused by receiving and processing the cascaded wake-up frame according to the wake-up delay time, determines the local remaining waiting time, and after the local remaining waiting time has elapsed, switches the basic sleep wake-up cycle to a high-frequency sampling cycle to collect the environmental parameters, so that the downstream target node switches to the high-frequency sampling cycle before the environmental parameters are expected to arrive. The duration of the high-frequency sampling period is shorter than the duration of the basic sleep-wake period.

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