Low-power mesh distributed radiation intelligent monitoring system based on adaptive fusion algorithm of double GM tubes

Abstract

The application belongs to the cross field of radiation safety monitoring and Internet of Things technology, and particularly relates to a low-power consumption Mesh distributed radiation intelligent monitoring system based on a double GM tube adaptive fusion algorithm. In order to solve the defects of the wireless radiation monitoring system, such as limited communication distance, limited node quantity, poor network reliability and the like, the application adopts a low-power consumption Bluetooth Mesh network (BLE Mesh) architecture, integrates a double-channel Geiger-Muller (GM) tube radiation detector, a sliding window CPM algorithm, an adaptive range selection and weighted fusion algorithm, an intelligent multi-level alarm mechanism and a remote dynamic configuration function, and realizes large-range, multi-node, self-organizing network, low-power consumption distributed ionizing radiation real-time monitoring and intelligent early warning.

Description

Technical Field

[0001] This invention belongs to the intersection of radiation safety monitoring and Internet of Things technology, specifically involving a low-power Mesh distributed intelligent radiation monitoring system based on a dual-GM tube adaptive fusion algorithm. Background Technology

[0002] With the rapid development of fields such as nuclear energy, medical radiation, and industrial flaw detection, radiation safety monitoring has become increasingly important. Traditional radiation monitoring systems have many problems, including limitations in wired connections (traditional systems mostly use wired connections to connect monitoring points, resulting in complex wiring, high costs, and poor flexibility); limitations in single-point monitoring (a single monitoring device can only monitor a local area, unable to achieve large-scale distributed monitoring); data silos (data from each monitoring point is independent, lacking a unified data aggregation and analysis platform); delayed alarm response (traditional systems have fixed alarm thresholds that cannot be dynamically adjusted according to actual conditions, and alarm responses are not timely enough); and high maintenance costs, making system expansion and maintenance difficult, requiring on-site operation by professional personnel. While existing wireless radiation monitoring systems have solved the wiring problem, most use a star topology, which has drawbacks such as limited communication distance, limited number of nodes, and poor network reliability. Therefore, there is an urgent need for a new type of distributed intelligent radiation monitoring system that can achieve large-scale, multi-node, self-organizing, low-power radiation monitoring, and has functions such as remote configuration, intelligent alarm, and data visualization. Summary of the Invention

[0003] To address the aforementioned technical issues, this invention provides a low-power mesh distributed radiation intelligent monitoring system based on a dual-GM tube adaptive fusion algorithm. It employs a Bluetooth Low Energy Mesh (BLE Mesh) network architecture and integrates a dual-channel Geiger-Miller (GM) tube radiation detector, a sliding window CPM algorithm, an adaptive range selection and weighted fusion algorithm, an intelligent multi-level alarm mechanism, and remote dynamic configuration functionality. This enables large-scale, multi-node, self-organizing, and low-power distributed real-time monitoring and intelligent early warning of ionizing radiation.

[0004] A low-power mesh distributed intelligent radiation monitoring system based on a dual-GM tube adaptive fusion algorithm includes a control platform, a central gateway, and multiple radiation monitoring nodes. These nodes upload real-time data to the control platform via the central gateway. The platform displays the data from each node on a screen. Clients can set threshold alarms for radiation and temperature / humidity for each node through the control platform, and also manage data and access historical data. The system is suitable for applications requiring large-scale, multi-point, real-time monitoring of ionizing radiation levels, such as perimeter monitoring of nuclear facilities, environmental supervision of medical radiology departments, safety protection of industrial irradiation workshops, and monitoring of radioactive material storage sites.

[0005] The multiple radiation monitoring nodes consist of one master node and multiple slave nodes. The master node and slave nodes communicate bidirectionally. The master node sends various commands and instructions to the slave nodes, and the slave nodes feed back various monitoring data they have collected to the master node. At the same time, information is transmitted between the slave nodes.

[0006] The host node integrates a first main control chip, an HMI touchscreen, an intelligent alarm module, a first BLE Mesh communication module, and a data upload interface. The first main control chip is used for system control and data processing; the HMI touchscreen is used for human-machine interaction, data display, and system configuration; the intelligent alarm module is used for intelligent alarm analysis; the first BLE Mesh communication module is used for wireless communication with slave nodes; and the data upload interface is used to upload aggregated data to an external platform.

[0007] The slave node integrates a second master control chip, a dual GM tube radiation detector, a temperature and humidity sensor, a buzzer alarm module, and a BLE Mesh communication module. The second master control chip is used for node control and data processing. The dual GM tube radiation detector includes a high-sensitivity GM tube and a large-range GM tube for radiation detection at different dose rates. The temperature and humidity sensor is used to collect ambient temperature and humidity data. The buzzer alarm module is used for local sound alarms. The second BLE Mesh communication module is used for data reporting and receiving configuration commands.

[0008] Furthermore, both the first and second BLE Mesh communication modules adopt a multi-hop Mesh topology and follow the Bluetooth Mesh Protocol. Both the first and second BLE Mesh communication modules enable relay functionality, supporting self-organizing networks, self-healing, and multi-hop transmission.

[0009] Furthermore, the dual-GM tube radiation detector employs a dual-GM tube adaptive range selection and weighted fusion algorithm, based on the reference dose rate D. ref The final dose rate D is output using a piecewise function within the specified interval. out :

[0010] When D ref < D low At that time, D out = D1, select high-sensitivity GM tube data;

[0011] When D low ≤ D ref ≤ D high At that time, D out = w(D ref )·D1+w(Dref )]·D2, using weighted fusion, where w(D ref ) = (D high -D ref ) / (D high -D low );

[0012] When D ref > D high At that time, D out = D2, select large-range GM tube data;

[0013] D1 and D2 represent the radiation dose rates of the high-sensitivity GM tube and the large-range GM tube, respectively.

[0014] Furthermore, the radiation dose rate is calculated using the sliding window CPM algorithm, with the following specific steps:

[0015] The GM transistor pulse signal is captured via GPIO interrupt, and the pulse count N is performed every 6 seconds. 6s ;

[0016] Maintain a circular buffer with 10 six-second windows and calculate the 60-second CPM value: CPM 60s = Σ(i=0 to 9) N 6s [i];

[0017] The radiation dose rate is calculated using the dose rate conversion formula: D(μSv / h) = CPM 60s ×K, where K is the calibration coefficient for the GM tube.

[0018] Furthermore, the sliding window CPM algorithm employs a circular buffer data structure and updates the CPM value through a recursive relationship: CPM(n) = CPM(n-1) - N old + N new , where N old For the old data that is overwritten, N new For newly acquired data, the dose rate data is updated every 6 seconds.

[0019] Furthermore, the buzzer alarm module includes a dual-mode threshold judgment and a delayed alarm anti-false triggering mechanism. The dual-mode threshold judgment is OR mode and AND mode. In OR mode, the buzzer alarm module triggers an alarm when it detects that the radiation monitoring value of any GM tube exceeds a preset threshold. In AND mode, the buzzer alarm module triggers an alarm only when it detects that the radiation monitoring values ​​of both GM tubes exceed the preset threshold simultaneously. The delayed alarm anti-false triggering mechanism is that the buzzer alarm module has a built-in delay counter, and the buzzer alarm is triggered only when the radiation monitoring values ​​collected N times consecutively exceed the preset threshold.

[0020] Furthermore, the intelligent alarm module realizes intelligent alarm based on historical data patterns, radiation cloud map area assessment, active radiation source trajectory prediction and multi-parameter cross-validation. Specifically, it includes: dynamic threshold alarm based on historical data patterns, radiation cloud map drawing and area risk assessment alarm, active radiation source trajectory tracking and prediction alarm, and a false alarm filtering mechanism based on multi-parameter fusion.

[0021] The dynamic threshold alarm based on historical data patterns: The host node stores historical radiation monitoring data of each slave node under different time periods and different temperature and humidity environments through the HMI touch screen, constructs a multi-dimensional analysis model, automatically calculates the time-based and scenario-based fluctuation range of radiation values ​​of each node, and generates a dynamic baseline; when the real-time radiation monitoring value exceeds the preset standard deviation of the corresponding scenario dynamic baseline, or when the continuous sampling value shows a step-like increase and the slope exceeds the preset threshold, a first-level warning is triggered; if the upward trend continues and is accompanied by sudden changes in temperature and humidity, it is upgraded to a second-level alarm, and a historical data comparison report is pushed.

[0022] The radiation cloud map drawing and regional risk assessment alarm are as follows: Combining the distributed deployment location information of the slave nodes, an interpolation algorithm is used to convert the real-time radiation monitoring data of each slave node into a dynamic radiation cloud map covering the monitoring area. Different colors are used to mark different radiation levels, and the map is displayed in real time on the HMI touch screen. When a preset number of adjacent nodes in the radiation cloud map are at a high radiation level, and the area of ​​the high radiation block exceeds a preset value, it is marked as a risk area and a regional alarm is triggered. If the risk area continues to expand, the buzzer alarm modules of the surrounding slave nodes are linked, and the buzzer volume is adjusted according to the principle of stronger sound near and weaker sound far, and the direction of risk spread is marked.

[0023] The active radiation source trajectory tracking and prediction alarm: By analyzing the time sequence of radiation value changes, communication timestamps and node spacing of adjacent slave nodes, the movement path, movement speed and movement direction of the active radiation source are fitted, and the trajectory curve is drawn in real time on the HMI touch screen; Based on historical trajectory data, a linear prediction model is used to predict the possible location of the radiation source in the future within a preset time. If the predicted path passes through a preset sensitive area, an early warning is triggered and a reminder message is pushed.

[0024] The multi-parameter fusion false alarm filtering mechanism works as follows: when a single slave node detects that the radiation value exceeds the threshold, it first checks whether the temperature and humidity data of the node are within the normal working range, and at the same time checks the communication status between the node and the surrounding nodes; if the temperature and humidity exceed the normal range or only the node exceeds the threshold in isolation while the data of the surrounding nodes are normal, the delay alarm count is extended; if multiple nodes exceed the threshold at the same time, the time difference and spatial distance of each node exceeding the threshold are compared to perform cross-verification, and an alarm is triggered after eliminating independent false alarm factors.

[0025] Furthermore, the host node remotely and dynamically configures the slave node through the first BLE Mesh communication module and the second BLE Mesh communication module, including three methods: broadcast configuration, unicast configuration, and real-time query.

[0026] The broadcast configuration is that all slave nodes receive the configuration command simultaneously.

[0027] The unicast configuration specifies a specific target node ID, and only the corresponding slave node receives the configuration instruction.

[0028] The real-time query allows the host node to query the current configuration parameters and operating status of any slave node at any time.

[0029] Furthermore, the specific process of the remote dynamic configuration is as follows:

[0030] The master node sends a threshold configuration message, which is transmitted to the slave node via the first BLE Mesh communication module and the second BLE Mesh communication module. After receiving the message, the slave node updates the configuration parameters and saves them to the Flash memory. Then, it sends a threshold status response back to the master node. The configuration parameters are not lost when power is off.

[0031] Furthermore, the HMI touchscreen has functions such as data visualization display, threshold parameter configuration, multi-level user permission management, operation log recording and password protection, and displays the connection status of each slave node, the fused radiation data, temperature and humidity data and historical data curves in real time.

[0032] Furthermore, the system adopts an all-round low-power design, is based on the BLE 5.0 low-power protocol, the sensor adopts a periodic intermittent sampling method, and supports sleep mode.

[0033] Compared with the prior art, the present invention has significant technical advantages and practical value, as follows:

[0034] In terms of monitoring coverage, the system relies on a BLE Mesh multi-hop network architecture, with a single node communication distance of up to 100 meters. Through multi-hop relay functionality, it can achieve wide-area coverage ranging from hundreds of meters to several kilometers. It supports flexible configuration of 1-255 slave nodes, fully meeting the distributed monitoring needs of large venues. Furthermore, the network possesses self-organizing and self-healing characteristics; the failure of a single node will not affect the stable operation of the overall network. At the deployment and application level, the system uses wireless communication, eliminating the need for additional cabling, significantly reducing installation costs and construction difficulty. Node locations can be flexibly adjusted, adapting to complex and difficult-to-cable environments and facilitating the rapid deployment of temporary monitoring points, thus meeting the usage requirements of different scenarios.

[0035] In terms of measurement accuracy, the system innovatively adopts dual GM tube dual-channel detection technology, forming complementary advantages to cover wide-range monitoring needs. Combined with a sliding window algorithm, the acquired data is smoothed, effectively reducing data fluctuations. Simultaneously, temperature and humidity sensors are integrated to collect environmental parameters, providing real-time calibration data for radiation, achieving a data accuracy of 0.1 μSv / h and ensuring the accuracy of measurement results. The intelligent alarm function responds promptly, with slave nodes enabling local real-time detection. Alarm delay is less than 6 seconds, and a delayed alarm mechanism avoids false alarms caused by instantaneous pulse interference. An intermittent buzzer mode is also designed to reduce system power consumption while ensuring alarm effectiveness. Even if disconnected from the host, the slave can still independently trigger the alarm, improving the reliability of safety assurance.

[0036] In terms of system management and user experience, the host node supports remote configuration of slave devices via BLE Mesh network, covering three methods: broadcast configuration, unicast configuration, and real-time query. Configuration parameters can be persistently stored in Flash memory, and will not be lost when power is off. Maintenance tasks such as threshold adjustment can be completed without on-site operation, significantly reducing management costs. The host-integrated HMI touch screen adopts a graphical interactive interface, which can display the monitoring data, operating status, and historical data curves of all nodes in real time. It supports touch input of threshold parameters, selection of alarm mode, setting of delay count and beep interval, etc. It also has multi-level permission management, operation log recording, and password protection functions, ensuring both intuitive and convenient operation and system security.

[0037] In terms of battery life and expandability, the system adopts a comprehensive low-power design based on the BLE 5.0 low-power protocol. It features intermittent sensor sampling, timed data reporting, and intermittent buzzer alarm modes, and supports sleep mode. It can operate continuously for several months using battery power, ensuring long-lasting and stable battery life. The system adopts a modular design concept, which facilitates functional expansion. It supports firmware OTA upgrades and can integrate additional functions such as GPS positioning and 4G upload according to actual needs. It is also compatible with the standard BLE Mesh protocol, has good interoperability, and provides ample space for subsequent system upgrades and functional expansion. Attached Figure Description

[0038] Figure 1 This is a network topology diagram of a distributed intelligent radiation monitoring system.

[0039] Figure 2 Schematic diagram of high-voltage power supply and signal conditioning circuit for node dual-tube detector.

[0040] Figure 3 This is a schematic diagram of a node pulse signal shaping and isolation circuit.

[0041] Figure 4 This is for the control platform display page and the slave control page. Detailed Implementation

[0042] The technical solution of this application will be described in detail below with reference to the accompanying drawings.

[0043] like Figure 1 and Figure 4 As shown in the figure, a low-power Mesh distributed radiation intelligent monitoring system based on a dual-GM tube adaptive fusion algorithm in this embodiment includes a control platform, a central gateway, and multiple radiation monitoring nodes. The multiple radiation monitoring nodes upload real-time data to the control platform through the central gateway. The multiple radiation monitoring nodes consist of a master node and multiple slave nodes. The master node and slave nodes communicate bidirectionally. The master node sends various commands and instructions to the slave nodes, and the slave nodes feed back various monitoring data they have collected to the master node. At the same time, information is transmitted between the slave nodes.

[0044] The control platform consists of a central gateway and monitoring nodes. The nodes exchange data via BLE mesh, and each node can also transmit data to the gateway independently.

[0045] The host node serves as the data aggregation and configuration management center for the entire system. It integrates a first main control chip (nRF52832), an HMI touchscreen, an intelligent alarm module, a first BLE Mesh communication module, and a data upload interface. The first main control chip is used for system control and data processing; the HMI touchscreen is used for human-machine interaction, data display, and system configuration; the intelligent alarm module is used for intelligent alarm analysis; the first BLE Mesh communication module is used for wireless communication with slave nodes; and the data upload interface is used to upload aggregated data to the control platform.

[0046] The slave node integrates a second master control chip (nRF52832 master control chip), a dual GM tube radiation detector, a temperature and humidity sensor, a buzzer alarm module, and a BLE Mesh communication module. The second master control chip has built-in Mesh network functionality, allowing stable access to the system's BLE Mesh network for node control and data processing. The dual GM tube radiation detector features differentiated characteristics, including a high-sensitivity GM tube (suitable for low dose rate monitoring) and a large-range GM tube (suitable for high dose rate monitoring). These two types of gamma counters adapt to different environments and are used for radiation detection across different dose rate ranges. The temperature and humidity sensor (SHT31) collects ambient temperature and humidity data, performing real-time calibration on the radiation data detected by the GM tubes to ensure the accuracy of radiation monitoring data and improve measurement precision, achieving a measurement accuracy of 0.1 μSv / h. The buzzer alarm module provides local audible alarms. The second BLE Mesh communication module is used for data reporting and receiving configuration commands.

[0047] In this embodiment, the system adopts a master-slave architecture, consisting of one master node and multiple slave nodes. The number of slave nodes can be flexibly configured within the range of 1-255. The master node and slave nodes can achieve bidirectional communication. The master can send various commands to the slaves, and the slaves can feed back various monitoring data they have collected to the master. At the same time, the slave nodes can transmit information to each other, ensuring the flexibility and reliability of data transmission.

[0048] The second BLE Mesh communication module adopts a multi-hop mesh topology and follows the Bluetooth Mesh Protocol. Both the first and second BLE Mesh communication modules enable relay functionality. The BLE Mesh communication network corresponds to the BLE Mesh communication modules and possesses core network characteristics such as self-organizing, self-healing, and multi-hop relay. It has also been specifically optimized for radiation monitoring applications. All nodes enable relay functionality to achieve multi-hop transmission and expand network coverage. Combined with an automatic routing mechanism, it improves communication reliability, supports group address communication for efficient one-to-many interaction, and sets slave nodes to automatically report data every 30 seconds to keep synchronized with the sensor sampling cycle, effectively reducing network load and saving system power consumption.

[0049] The BLE Mesh communication network uses a custom Vendor Model data transmission protocol, implemented based on the BLE Mesh Access Layer. The slave nodes automatically report data every 30 seconds to keep synchronized with the sensor sampling period.

[0050] The ambient temperature and humidity data collected by the SHT31 temperature and humidity sensor is used to calibrate the radiation data detected by the GM tube in real time, improving the measurement accuracy to 0.1 μSv / h.

[0051] This system employs a dual-GM tube adaptive range selection and weighted fusion algorithm. Traditional single-GM tube radiation monitoring systems have inherent contradictions. High-sensitivity GM tubes offer advantages such as high signal-to-noise ratio and good measurement accuracy at low dose rates, but are prone to saturation at high dose rates and suffer from dead-time effects. Large-range GM tubes, on the other hand, offer good linearity and are less prone to saturation at high dose rates, but suffer from insufficient sensitivity and large statistical errors at low dose rates. The innovative dual-tube complementary design concept utilizes a complementary configuration of two GM tubes: a high-sensitivity tube and a large-range tube. It leverages the advantageous measurement ranges of different GM tubes, and an intelligent algorithm selects the optimal data source. Weighted fusion is performed in the overlapping range to achieve high-precision measurement across the entire range. This algorithm intelligently selects the optimal measurement channel or performs data fusion by analyzing the measurement data from two GM tubes with different characteristics in real time, achieving high-precision radiation dose rate measurement across the entire range.

[0052] The dual-GM tube radiation detector employs a dual-GM tube adaptive range selection and weighted fusion algorithm, based on the reference dose rate D. ref The final dose rate D is output using a piecewise function within the interval of the (initial count rate) data. out :

[0053] When D ref < D low At that time, D out = D1, select high-sensitivity GM tube data;

[0054] When D low ≤ D ref ≤ D high At that time, D out = w(D ref )·D1+w(D ref )]·D2, using weighted fusion, where w(D ref ) = (D high -D ref ) / (D high -D low );

[0055] When D ref > D high At that time, D out = D2, select large-range GM tube data;

[0056] D1 and D2 represent the radiation dose rates of the high-sensitivity GM tube and the large-range GM tube, respectively.

[0057] In the dual GM tube adaptive range selection and weighted fusion algorithm, the low dose threshold D low =1.0 μSv / h, high dose threshold D high =10.0 μSv / h, and a linear weighting function is used in the transition interval to achieve a smooth transition and avoid data abrupt changes.

[0058] In the dual GM tube radiation detector, the high-sensitivity GM tube is type M4011, with an operating voltage of 400V and an effective range of 0.01-100 μSv / h; the large-range GM tube is type J613Y, with an operating voltage of 500V and an effective range of 0.05-500 μSv / h.

[0059] The radiation dose rate is calculated using the sliding window CPM algorithm, and the specific steps are as follows:

[0060] 1. Capture the GM transistor pulse signal via GPIO interrupt, and count the pulses N every 6 seconds. 6s ;

[0061] N 6s= The total number of pulses detected by the GM tube during this time period;

[0062] Wherein: the sampling period is Δt = 6 seconds, and the counter is accumulated through GPIO interrupt.

[0063] 2. The counting algorithm adopts the sliding window algorithm. Every 6 seconds, the CPM (counts per minute) is calculated through the sliding window. A circular buffer of 10 6-second windows is maintained to calculate the CPM value over 60 seconds.

[0064] 60-second CPM calculation (sliding window method)

[0065] CPM 60s = Σ(i=0 to 9) N 6s [i]

[0066] Where: N 6s [i] represents the number of pulses in the i-th 6-second window; number of windows: 10; total time span: 60 seconds. Sliding window data structure:

[0067] Circular buffer: [N0, N1, N2, N3, N4, N5, N6, N7, N8, N9]

[0068] └────────────── 60-second total window ──────────────┘

[0069] Mathematical expression:

[0070] CPM at the nth update:

[0071] CPM(n) = Σ(i=0 to 9) N[(ni) mod 10]

[0072] Recurrence relation:

[0073] A circular buffer data structure is used to update the CPM value through a recursive relationship:

[0074] CPM(n) = CPM(n-1) - N old + N new

[0075] Where N old For the old data that is overwritten, N new For newly acquired data, the dose rate data is updated every 6 seconds.

[0076] 3. Dose rate conversion

[0077] Converting CPM values ​​to μSv / h (microsieverts per hour) allows users to intuitively understand their radiation dose. This is achieved by calculating the radiation dose rate using the dose rate conversion formula:

[0078] D(μSv / h) = CPM 60s ×K

[0079] Where: D is the radiation dose rate (µSv / hour); CPM 60s The total number of pulses within a 60-second sliding window is given by K, which is the calibration coefficient for the GM tube.

[0080] This system employs the CPM algorithm, an innovative radiation measurement method that successfully resolves the contradiction between real-time performance and accuracy inherent in traditional methods. By maintaining a 60-second statistical window and updating it every 6 seconds, the algorithm achieves characteristics such as rapid response, accurate measurement, low resource consumption, strong anti-interference, standard compatibility, and network friendliness. It is particularly suitable for distributed intelligent radiation monitoring and supervision systems requiring real-time monitoring and multi-point deployment, providing a reliable technical solution for scenarios such as nuclear facilities, medical institutions, and industrial irradiation.

[0081] Figure 2 This diagram illustrates the high-voltage power supply and signal conditioning circuit for a dual-transistor detector. Its core function is to provide a stable high-voltage bias for the two GM transistors and to perform preliminary processing of the detection signal. The PA6 pin of the main control MCU outputs a PWM signal, which, after DC blocking coupling via a 10μF capacitor, drives a push-pull structure composed of MMBT3904 transistors through a voltage divider network of 1kΩ and 100kΩ resistors. This controls the enable and output of the half-bridge gate driver chip. The output Y of U2 drives the power MOSFET MMBTA42. A multi-stage voltage multiplier rectifier circuit, consisting of a 1mH inductor, diodes D3-D7 (FR107), and 47nF capacitors C7, C8, C11, C12, and C13, boosts the input voltage to approximately 500V and 400V, providing high operating voltages for the two transistors. The feedback network, composed of 1MΩ and 51kΩ resistors and a high-voltage diode, monitors the high-voltage output. Closed-loop regulation is achieved through the feedback pin of U2 to ensure the stability of the high-voltage output. The input power supply is current-limited by a 2Ω resistor and filtered by a capacitor network to provide stable power to the entire circuit. C9 in the PWM signal path provides DC blocking coupling to prevent DC components from affecting the drive circuit, and R17 is pulled down to ground to ensure reliable shutdown of the drive stage when there is no PWM signal, protecting Q1 from false triggering. Diodes D3-D7 in the voltage multiplier circuit are FR107 fast recovery diodes, working with capacitors to achieve efficient voltage multiplication while suppressing high-voltage spikes. This circuit can be used to monitor the operating current of the high-voltage output circuit. This circuit, through a PWM-driven half-bridge voltage multiplier topology, efficiently generates dual high voltages. Simultaneously, through feedback voltage regulation and protection design, it provides a stable and reliable operating bias for the dual GM tube detector, forming a key hardware foundation for high-precision radiation detection.

[0082] Figure 3This is a schematic diagram of a node pulse signal shaping and isolation circuit. Its core function is to shape, filter, and level-convert the raw ionization pulse signal output from dual GM transistors to meet the interrupt acquisition requirements of the MCU. The circuit uses an SN74HC14PWR Schmitt trigger as its core. After current limiting by a 1kΩ resistor, the raw pulse signal output from the GM transistors is connected to an RC filter network composed of R1, R2, and C1 to filter out high-frequency noise and interference. Diode D11N4148WS is used to clamp overshoot voltage and protect the Schmitt trigger input pin. The raw signal is input through the 1A terminal of the Schmitt trigger, shaped at the 2Y terminal, and output as a standard digital pulse OV1. This pulse signal can be directly connected to the MCU's GPIO interrupt pin for pulse counting.

[0083] The right-side channel structure is symmetrical to the left. The original pulse signal CP2 output from the GM transistor is current-limited by a 1kΩ resistor and then connected to an RC filter network composed of R7, R8, and C4. A diode is used for clamping protection. The original signal is input through the 4A terminal of a Schmitt trigger and shaped into a standard digital pulse OV2 by the 6Y terminal. This pulse signal can also be connected to another GPIO interrupt pin of the MCU to realize independent acquisition and counting of pulses from the two GM transistors. This circuit effectively eliminates noise and jitter in the GM transistor output signal through the hysteresis characteristic of the Schmitt trigger, shaping irregular ionized pulses into clear and stable digital signals. At the same time, the RC filtering and diode clamping design improve the signal's anti-interference capability, providing a reliable hardware foundation for high-precision pulse counting in subsequent dual-transistor fusion algorithms.

[0084] In terms of data transmission, the system implements a custom Vendor Model data transmission protocol based on BLE Mesh Access Layer to ensure the professionalism and adaptability of data transmission.

[0085] The buzzer alarm module includes a dual-mode threshold judgment and a delayed alarm anti-false triggering mechanism. The dual-mode threshold judgment is OR mode and AND mode. In OR mode, the buzzer alarm module triggers an alarm when it detects that the radiation monitoring value of any GM tube exceeds a preset threshold. In AND mode, the buzzer alarm module triggers an alarm only when it detects that the radiation monitoring values ​​of both GM tubes exceed the preset threshold simultaneously. The delayed alarm anti-false triggering mechanism is that the buzzer alarm module has a built-in delay counter. The buzzer alarm is only triggered when the radiation monitoring values ​​collected N times consecutively exceed the preset threshold, thereby avoiding false alarms caused by instantaneous pulse interference and ensuring alarm accuracy.

[0086] The intelligent alarm module breaks through the limitations of fixed thresholds and fixed logic, and realizes intelligent alarm based on historical data patterns, radiation cloud map area assessment, active radiation source trajectory prediction and multi-parameter cross-validation. Specifically, it includes: dynamic threshold alarm based on historical data patterns, radiation cloud map drawing and regional risk assessment alarm, active radiation source trajectory tracking and prediction alarm, and a false alarm filtering mechanism based on multi-parameter fusion.

[0087] Among them, the dynamic threshold alarm based on historical data patterns: the host node stores historical radiation monitoring data of each slave node under different time periods and different temperature and humidity environments through the HMI touch screen, builds a multi-dimensional analysis model, automatically calculates the time-based and scenario-based fluctuation range of radiation values ​​of each node, and generates a dynamic baseline; when the real-time radiation monitoring value exceeds the preset standard deviation of the corresponding scenario dynamic baseline, or when the continuous sampling value shows a step-like increase and the slope exceeds the preset threshold, a first-level warning is triggered; if the upward trend continues and is accompanied by sudden changes in temperature and humidity, it is upgraded to a second-level alarm and a historical data comparison report is pushed.

[0088] Radiation cloud map drawing and regional risk assessment alarm: Combining the distributed deployment location information of slave nodes, an interpolation algorithm is used to convert the real-time radiation monitoring data of each slave node into a dynamic radiation cloud map covering the monitoring area. Different colors are used to mark different radiation levels, which are displayed in real time on the HMI touch screen. When a preset number of adjacent nodes in the radiation cloud map are at a high radiation level and the area of ​​the high radiation block exceeds a preset value, it is marked as a risk area and a regional alarm is triggered. If the risk area continues to expand, the buzzer alarm modules of the surrounding slave nodes are linked, and the buzzer volume is adjusted according to the principle of stronger sound near and weaker sound far, and the direction of risk spread is marked.

[0089] Active radiation source trajectory tracking and prediction alarm: By analyzing the time sequence of radiation value changes, communication timestamps and node spacing of adjacent slave nodes, the movement path, speed and direction of the active radiation source are fitted, and the trajectory curve is drawn in real time on the HMI touch screen; Based on historical trajectory data, a linear prediction model is used to predict the possible location of the radiation source in the future within a preset time. If the predicted path passes through a preset sensitive area, an early warning is triggered and a reminder message is pushed.

[0090] Multi-parameter fusion false alarm filtering mechanism: When a single slave node detects that the radiation value exceeds the threshold, it first checks whether the temperature and humidity data of the node are within the normal working range, and at the same time checks the communication status between the node and the surrounding nodes; if the temperature and humidity exceed the normal range or only the node exceeds the threshold in isolation and the data of the surrounding nodes are normal, the delay alarm count is extended; if multiple nodes exceed the threshold at the same time, the time difference and spatial distance of each node exceeding the threshold are compared to perform cross-validation, and an alarm is triggered after eliminating independent false alarm factors.

[0091] The system also supports remote dynamic configuration technology. The master node performs remote dynamic configuration of the slave nodes through the first BLE Mesh communication module and the second BLE Mesh communication module, including three methods: broadcast configuration, unicast configuration and real-time query. Broadcast configuration means that all slave nodes receive the configuration command at the same time; unicast configuration means that a specific target node ID is specified, and only the corresponding slave node receives the configuration command; real-time query means that the master node can query the current configuration parameters and running status of any slave node at any time.

[0092] The specific process of remote dynamic configuration is as follows: the host node sends a threshold configuration message, which is transmitted to the slave node through the first BLE Mesh communication module and the second BLE Mesh communication module. After receiving the message, the slave node updates the configuration parameters and saves them to the Flash memory. Then, it sends a threshold status response back to the host node. The configuration parameters are not lost when the power is off.

[0093] In addition, the system as a whole adopts a comprehensive low-power design. In addition to the energy-saving design such as intermittent buzzing and timed sampling and reporting mentioned above, based on the BLE 5.0 low-power protocol, the sensor adopts a 30-second intermittent sampling method and supports sleep mode. Battery power can enable continuous operation for several months, further optimizing the system's power consumption performance and ensuring long-term stable operation of the system.

[0094] The specific functions of the HMI touchscreen also include: data visualization display (real-time display of radiation values, temperature and humidity data, node operating status, and historical data curves of all slave nodes), threshold setting interface (supports touch input of threshold parameters, selection of alarm mode (OR / AND), setting of delay count and beep interval), and user management functions (supports multi-level permission management, operation log recording, and password protection), comprehensively covering system operation and supervision needs, and displaying the connection status of each slave node, the merged radiation data, temperature and humidity data, and historical data curves in real time.

[0095] The number of slave nodes can be flexibly configured from 1 to 255, and the communication distance of a single node can reach 100 meters. Through the multi-hop relay function, a wide range of coverage from hundreds of meters to several kilometers can be achieved.

[0096] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application and are not intended to limit it. Although this application has been described in detail with reference to the embodiments, those skilled in the art should understand that modifications or equivalent substitutions to the technical solutions of this application do not depart from the spirit and scope of the technical solutions of this application, and should all be covered within the scope of the claims of this application.

Claims

1. A low-power mesh distributed radiation intelligent monitoring system based on a dual-GM tube adaptive fusion algorithm, characterized in that, It includes a control platform, a central gateway, and multiple radiation monitoring nodes. The radiation monitoring nodes upload real-time data to the control platform through the central gateway. The multiple radiation monitoring nodes consist of a master node and multiple slave nodes. The master node and slave nodes communicate bidirectionally. The master node sends various commands and instructions to the slave nodes, and the slave nodes feed back various monitoring data they have collected to the master node. At the same time, information is transmitted between the slave nodes. The host node integrates a first main control chip, an HMI touchscreen, an intelligent alarm module, a first BLE Mesh communication module, and a data upload interface. The first main control chip is used for system control and data processing; the HMI touchscreen is used for human-machine interaction, data display, and system configuration; the intelligent alarm module is used for intelligent alarm analysis; the first BLE Mesh communication module is used for wireless communication with slave nodes; and the data upload interface is used to upload aggregated data to the control platform. The slave node integrates a second master control chip, a dual GM tube radiation detector, a temperature and humidity sensor, a buzzer alarm module, and a second BLE Mesh communication module. The second master control chip is used for node control and data processing. The dual GM tube radiation detector includes a high-sensitivity GM tube and a large-range GM tube for radiation detection at different dose rates. The temperature and humidity sensor is used to collect ambient temperature and humidity data. The buzzer alarm module is used for local sound alarms. The second BLE Mesh communication module is used for data reporting and receiving configuration commands.

2. The low-power Mesh distributed radiation intelligent monitoring system based on a dual-GM tube adaptive fusion algorithm according to claim 1, characterized in that, The second BLE Mesh communication module adopts a multi-hop Mesh topology and follows the Bluetooth Mesh Protocol. Both the first and second BLE Mesh communication modules enable relay functionality, supporting self-organizing networks, self-healing, and multi-hop transmission.

3. The low-power Mesh distributed radiation intelligent monitoring system based on a dual-GM tube adaptive fusion algorithm according to claim 2, characterized in that, The dual-GM tube radiation detector employs a dual-GM tube adaptive range selection and weighted fusion algorithm, based on the reference dose rate D. ref The final dose rate D is output using a piecewise function within the specified interval. out : When D ref < D low At that time, D out = D1, select high-sensitivity GM tube data; When D low ≤ D ref ≤ D high At that time, D out = w(D ref )·D1+w(D ref )]·D2, using weighted fusion, where w(D ref )= (D high -D ref ) / (D high -D low ); When D ref > D high At that time, D out = D2, select large-range GM tube data; D1 and D2 represent the radiation dose rates of the high-sensitivity GM tube and the large-range GM tube, respectively.

4. The low-power Mesh distributed radiation intelligent monitoring system based on a dual-GM tube adaptive fusion algorithm according to claim 3, characterized in that, The radiation dose rate is calculated using the sliding window CPM algorithm, and the specific steps are as follows: The GM transistor pulse signal is captured via GPIO interrupt, and the pulse count N is performed every 6 seconds. 6s ; Maintain a circular buffer with 10 six-second windows and calculate the 60-second CPM value: CPM 60s = Σ(i=0 to 9) N 6s [i], N 6s [i] represents the number of pulses in the i-th 6-second window; The radiation dose rate is calculated using the dose rate conversion formula: D(μSv / h) = CPM 60s ×K, where K is the calibration coefficient for the GM tube.

5. A low-power mesh distributed radiation intelligent monitoring system based on a dual-GM tube adaptive fusion algorithm according to claim 4, characterized in that, The sliding window CPM algorithm uses a circular buffer data structure and updates the CPM value through a recursive relationship: CPM(n) = CPM(n-1) - N old + N new , where N old For the old data that is overwritten, N new For newly acquired data, the dose rate data is updated every 6 seconds.

6. A low-power mesh distributed radiation intelligent monitoring system based on a dual-GM tube adaptive fusion algorithm according to claim 5, characterized in that, The buzzer alarm module includes a dual-mode threshold judgment and a delayed alarm anti-false triggering mechanism. The dual-mode threshold judgment is OR mode and AND mode. In OR mode, the buzzer alarm module triggers an alarm when it detects that the radiation monitoring value of any GM tube exceeds a preset threshold. In AND mode, the buzzer alarm module triggers an alarm only when it detects that the radiation monitoring values ​​of both GM tubes exceed the preset threshold simultaneously. The delayed alarm anti-false triggering mechanism is that the buzzer alarm module has a built-in delay counter. The buzzer alarm is only triggered when the radiation monitoring values ​​collected N times consecutively exceed the preset threshold.

7. A low-power mesh distributed radiation intelligent monitoring system based on a dual-GM tube adaptive fusion algorithm according to claim 6, characterized in that, The intelligent alarm module achieves intelligent alarm based on historical data patterns, radiation cloud map regional assessment, active radiation source trajectory prediction, and multi-parameter cross-validation. Specifically, it includes: dynamic threshold alarm based on historical data patterns, radiation cloud map drawing and regional risk assessment alarm, active radiation source trajectory tracking and prediction alarm, and a false alarm filtering mechanism based on multi-parameter fusion. The dynamic threshold alarm based on historical data patterns: The host node stores historical radiation monitoring data of each slave node under different time periods and different temperature and humidity environments through the HMI touch screen, constructs a multi-dimensional analysis model, automatically calculates the time-based and scenario-based fluctuation range of radiation values ​​of each node, and generates a dynamic baseline; when the real-time radiation monitoring value exceeds the preset standard deviation of the corresponding scenario dynamic baseline, or when the continuous sampling value shows a step-like increase and the slope exceeds the preset threshold, a first-level warning is triggered; if the upward trend continues and is accompanied by sudden changes in temperature and humidity, it is upgraded to a second-level alarm, and a historical data comparison report is pushed. The radiation cloud map drawing and regional risk assessment alarm are as follows: Combining the distributed deployment location information of the slave nodes, an interpolation algorithm is used to convert the real-time radiation monitoring data of each slave node into a dynamic radiation cloud map covering the monitoring area. Different colors are used to mark different radiation levels, and the map is displayed in real time on the HMI touch screen. When a preset number of adjacent nodes in the radiation cloud map are at a high radiation level, and the area of ​​the high radiation block exceeds a preset value, it is marked as a risk area and a regional alarm is triggered. If the risk area continues to expand, the buzzer alarm modules of the surrounding slave nodes are linked, and the buzzer volume is adjusted according to the principle of stronger sound near and weaker sound far, and the direction of risk spread is marked. The active radiation source trajectory tracking and prediction alarm: By analyzing the time sequence of radiation value changes, communication timestamps and node spacing of adjacent slave nodes, the movement path, movement speed and movement direction of the active radiation source are fitted, and the trajectory curve is drawn in real time on the HMI touch screen; Based on historical trajectory data, a linear prediction model is used to predict the possible location of the radiation source in the future within a preset time. If the predicted path passes through a preset sensitive area, an early warning is triggered and a reminder message is pushed. The multi-parameter fusion false alarm filtering mechanism works as follows: when a single slave node detects that the radiation value exceeds the threshold, it first checks whether the temperature and humidity data of the node are within the normal working range, and at the same time checks the communication status between the node and the surrounding nodes; if the temperature and humidity exceed the normal range or only the node exceeds the threshold in isolation while the data of the surrounding nodes are normal, the delay alarm count is extended; if multiple nodes exceed the threshold at the same time, the time difference and spatial distance of each node exceeding the threshold are compared to perform cross-verification, and an alarm is triggered after eliminating independent false alarm factors.

8. A low-power mesh distributed radiation intelligent monitoring system based on a dual-GM tube adaptive fusion algorithm according to claim 7, characterized in that, The host node remotely and dynamically configures the slave node through the first BLE Mesh communication module and the second BLE Mesh communication module, including three methods: broadcast configuration, unicast configuration and real-time query. The broadcast configuration is that all slave nodes receive the configuration command simultaneously. The unicast configuration specifies a specific target node ID, and only the corresponding slave node receives the configuration instruction. The real-time query allows the host node to query the current configuration parameters and operating status of any slave node at any time.

9. A low-power mesh distributed radiation intelligent monitoring system based on a dual-GM tube adaptive fusion algorithm according to claim 8, characterized in that, The specific process for remote dynamic configuration is as follows: The master node sends a threshold configuration message, which is transmitted to the slave node via the first BLE Mesh communication module and the second BLE Mesh communication module. After receiving the message, the slave node updates the configuration parameters and saves them to the Flash memory. Then, it sends a threshold status response back to the master node. The configuration parameters are not lost when power is off.

10. A low-power Mesh distributed radiation intelligent monitoring system based on a dual-GM tube adaptive fusion algorithm according to any one of claims 1-9, characterized in that, The system adopts an all-round low-power design, is based on the BLE 5.0 low-power protocol, uses a periodic intermittent sampling method for the sensor, and supports sleep mode.

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