Digital twin system for detecting and localizing natural gas leaks in integrated utility tunnels based on sound source localization.

Abstract

This system provides a digital twin system for detecting and localizing natural gas leaks in integrated utility tunnels based on sound source localization. [Solution] In this system, a methane sensor is placed inside the natural gas chamber of the integrated utility tunnel. When it detects that the methane concentration has reached a preset threshold, it sends an alarm signal to a mobile unit. Based on the alarm signal, the mobile unit autonomously moves to the natural gas leak area within the natural gas chamber and collects natural gas leak acoustic signals. The signal collection and positioning unit performs leak localization relative to the location of the natural gas leak source using a leak acoustic difference algorithm, and feeds back the localized location of the natural gas leak source to the mobile unit. The mobile unit autonomously moves to the location of the natural gas leak source and transmits the leak source location to the data aggregation unit of the integrated utility tunnel server. The twin system updates the localization results in a digital twin model in real time and virtually visualizes the integrated utility tunnel.

Description

Technical Field

[0001] The present invention relates to the field of digital twin technology, and particularly to a digital twin system for detecting and locating natural gas leakage in an integrated utility tunnel based on sound source localization.

Background Art

[0002] An integrated utility tunnel is a form of intensively utilizing urban underground space, which centrally lays municipal public pipelines (such as electricity, communication, water supply and drainage, natural gas, etc.) in the same space to achieve resource sharing and efficiency improvement in maintaining boundaries. However, when an accident, especially a natural gas leakage accident occurs in an integrated utility tunnel, it often brings extremely high risks.

[0003] Natural gas is a combustible and explosive gas. When it accumulates in a limited underground space, it is likely to cause explosions and fires, resulting in serious property losses and human casualties. Furthermore, natural gas leakage may also cause environmental pollution and secondary disasters, further increasing the scope and severity of the accident. Therefore, effective monitoring of integrated utility tunnels, especially the prevention and response to natural gas leakage accidents, is very important.

[0004] In an integrated utility tunnel, natural gas leakage may pose significant safety concerns. Many of the conventional natural gas leakage detection methods rely on direct detection by gas sensors. However, in a complex utility tunnel environment, the detection range of a single sensor is limited and it may be affected by interference from other factors, making it difficult to accurately locate the leakage source.

[0005] Therefore, it is urgent to provide a technical solution to address the above drawbacks of the prior art.

Summary of the Invention

[0006] The purpose of this application is to provide a digital twin system for detecting and localizing natural gas leaks in a combined utility tunnel based on sound source localization, in order to solve or mitigate the problems present in the prior art described above.

[0007] To achieve the above objective, this application provides the following technical solution.

[0008] This application provides a digital twin system for detecting and localizing natural gas leaks in a joint utility tunnel based on sound source localization, the system comprising a methane sensor located in the natural gas chamber of the joint utility tunnel, which is configured to monitor the methane concentration in the natural gas chamber in real time and to transmit an alarm signal when it is detected that the methane concentration in the natural gas chamber has reached a preset threshold, A mobile unit that receives an alarm signal transmitted from the methane sensor and autonomously moves to the natural gas leak area within the natural gas chamber based on the alarm signal, The signal acquisition and positioning unit is arranged in the mobile unit and is provided with a microphone array, wherein the microphone array is configured to acquire natural gas leak sound wave signals in the natural gas leak area, and in response to the natural gas leak sound wave signals, it uses a pre-constructed leak source positioning model to perform leak positioning to the location of the natural gas leak source in the natural gas leak area using a leak sound wave difference algorithm, and feeds back the positioned location of the natural gas leak source to the mobile unit so that the mobile unit autonomously moves to the corresponding location of the natural gas leak source, and transmits the location of the natural gas leak source to the data aggregation unit of the integrated utility tunnel server.

[0009] Preferably, the signal acquisition and localization unit is further configured to process the acquired natural gas leak sound wave signal based on the wavelet transform Kalman filter method to obtain spectral data of the natural gas leak sound wave signal, and to determine the location of the natural gas leak source within the natural gas leak area using the leak sound wave difference algorithm based on the obtained spectral data of the natural gas leak sound wave signal.

[0010] TIFF2026070449000002.tif21170

number

[0011] TIFF2026070449000004.tif28170

number

number

[0012] TIFF2026070449000007.tif24170

number

[0013] TIFF2026070449000009.tif59170

number

[0014] Preferably, the digital twin system further includes a physical simulation model of the integrated utility tunnel constructed according to the physical parameters of the integrated utility tunnel, The training dataset of the leakage source localization model is constructed based on the simulated positions of natural gas leakage sources and the corresponding time delay difference simulation data in the physical simulation model. The simulated positions of natural gas leakage sources and the corresponding time delay difference simulation data in the physical simulation model are obtained by using the physical simulation model to simulate the natural gas leakage acoustic signals at the positions of different natural gas leakage sources in the integrated utility tunnel, and determining the time delay difference simulation data of the simulation signals in the physical simulation model reaching any pair of microphone simulation sensors.

[0015] TIFF2026070449000011.tif40170

[0016] TIFF2026070449000012.tif44170

[0017] TIFF2026070449000013.tif37170

Number

Number

[0018] In the digital twin system for detecting and locating natural gas leakage in the comprehensive utility tunnel based on sound source localization according to an embodiment of the present application, the methane sensor is arranged in the natural gas chamber of the comprehensive utility tunnel, monitors the methane concentration in the natural gas chamber in real time, and when it detects that the methane concentration in the natural gas chamber has reached a preset threshold, it sends an alarm signal to the mobile unit. The mobile unit receives the alarm signal sent from the methane sensor, autonomously moves to the natural gas leakage area in the natural gas chamber based on the alarm signal, and a signal collection and localization unit is arranged in the mobile unit. A microphone array is provided in the signal collection and localization unit to collect the natural gas leakage sound wave signal in the natural gas leakage area, and according to the natural gas leakage sound wave signal, leakage localization is performed on the position of the natural gas leakage source in the natural gas leakage area by the leakage sound wave difference algorithm, and the position of the located natural gas leakage source is fed back to the mobile unit, and the mobile unit autonomously moves to the position of the corresponding natural gas leakage source and sends the position of the natural gas leakage source to the data aggregation unit of the comprehensive utility tunnel server. [[ID=E1]] [[ID=E2]]

[0019] [[ID=E3]] [[ID=E4]]Thereby, by using the monitoring of the natural gas leakage sound wave signal by the microphone array and accurately locating the natural gas leakage source from the sound wave difference, the problems that the detection range of the conventional gas sensor is limited and it is easily interfered in a complex environment are overcome, the natural gas leakage in the comprehensive utility tunnel can be detected timely, quickly and accurately, the accurate localization of the natural gas leakage source is supported, and the accident response time can be effectively shortened. [[ID=E5]] [[ID=E6]]

Brief Description of the Drawings

[0020] [[ID=E10]] [[ID=E11]]The drawings in the specification constituting a part of the present application are for providing a further understanding of the present application, and the exemplary embodiments and their descriptions of the present application are for interpreting the present application and do not unduly limit the present application. In the figures, [[ID=E12]] [[ID=E13]]

[0021] [[ID=E14]] [[ID=E15]] [Figure 1]This is a schematic diagram of a scenario for a digital twin system for detecting and localizing natural gas leaks in a combined utility tunnel based on sound source localization, according to some embodiments of this application. [Figure 2] This is a diagram illustrating the technical principle of a digital twin system for detecting and localizing natural gas leaks in a shared utility tunnel based on sound source localization, according to some embodiments of this application. [Figure 3] This is a flowchart illustrating the detection of natural gas leaks in a shared utility tunnel based on sound source localization according to some embodiments of this application. [Figure 4] These are design drawings of a digital twin-frame architecture according to several embodiments of this application. [Figure 5] These are two-dimensional spectral diagrams after wavelet transform according to some embodiments of this application. [Figure 6] These are one-dimensional spectral diagrams after wavelet transform according to some embodiments of this application. [Modes for carrying out the invention]

[0022] The present invention will be described in detail below with reference to the drawings and in conjunction with embodiments. Each example is provided by interpretation of this application and does not limit it. In fact, it will be apparent to those skilled in the art that modifications and variations can be made to this application as long as they do not deviate from the scope or spirit of this application. For example, features shown or described as part of one embodiment can be used in another embodiment to produce yet another embodiment. All other embodiments that can be obtained by those skilled in the art based on the embodiments of the present invention should all fall within the scope of protection of the present invention.

[0023] Currently, conventional gas sensors are susceptible to interference when monitoring natural gas leaks in complex utility tunnels, resulting in inaccurate localization of natural gas leak sources. To address this problem, this application proposes a digital twin system for detecting and localizing natural gas leaks in utility tunnels based on sound source localization. This system utilizes a microphone array and acoustic wave analysis technology to accurately localize the location of natural gas leaks, thereby enabling timely and accurate localization of natural gas leak sources in complex utility tunnel environments.

[0024] The digital twin system is hierarchically designed to consist of a physical layer, a data layer, an algorithmic layer, and a functional layer. The physical layer includes physical entities and logical rules. The physical entities are actual utility tunnel facilities and the natural gas transport pipelines contained within them, while the logical rules define the operating methods and behavioral rules for these physical objects in the digital twin system. The logical layer ensures that the system can accurately map the real-world physical state and forms the basis of the digital twin system data.

[0025] The data layer is responsible for collecting and managing fixed data from the physical space and real-time sensor data, including environmental data, methane sensor data, and leak detection data in the utility tunnel, ensuring that the algorithm layer can process and analyze data accurately and in a timely manner. The algorithm layer analyzes and computes the raw data provided by the data layer using techniques such as deep learning, signal processing, and noise reduction. Deep learning models are used to identify the characteristics of natural gas leaks, and combined with signal processing techniques, the accuracy of data analysis is improved, enabling precise localization of the leak source.

[0026] The functional layer specifically includes leak alarms, visualization of utility tunnel data, and localization of leak sources. By performing real-time monitoring and data analysis, the functional layer visually displays the status of natural gas in the utility tunnel, issues alarms when an anomaly is detected, and localizes the leak location, enabling timely action.

[0027] Specifically, the integrated utility tunnel server models the experimental modules and various sensors of the integrated utility tunnel using Blender, obtaining virtual models of various objects on the experimental platform. Then, materials are assigned to the virtual models using shaders, and finally, texture maps are obtained through a baking process. The virtual models and their corresponding texture maps are then imported into Unity3D. A digital twin system is constructed in Unity3D, and the model positions are set in Unity3D based on the geometric relationships of the various virtual models.

[0028] As shown in Figures 1 to 6, the digital twin system for detecting and localizing natural gas leaks in the integrated utility tunnel based on sound source localization includes a methane sensor, a mobile unit, and a signal acquisition and localization unit. The methane sensors are placed inside the natural gas chamber of the integrated utility tunnel, with one methane sensor placed every 15 meters according to the pipeline construction of the urban underground integrated utility tunnel, allowing for real-time monitoring of the methane concentration inside the natural gas chamber. The natural gas chamber is the space inside the integrated utility tunnel where the natural gas pipeline is located.

[0029] The process of detecting natural gas leaks in a joint utility tunnel based on sound source localization will be explained below with reference to Figure 3, in accordance with the configuration of the digital twin system.

[0030] In step S101, if a natural gas leak occurs in the pipeline, the methane sensor monitors that the methane concentration in the natural gas chamber has reached a preset threshold and transmits a natural gas leak alarm signal.

[0031] In step S102, the mobile unit receives an alarm signal transmitted from the methane sensor and autonomously moves to the natural gas leak area within the natural gas chamber based on the alarm signal. An autonomous navigation mobile robot is used as the mobile unit and is capable of autonomously moving within the utility tunnel. Specifically, the mobile robot is equipped with a wireless communication module connected to the internal network of the utility tunnel, and the alarm signal is rapidly transmitted to the mobile unit via internal network communication. The alarm signal also includes the number and coordinate information of the methane sensor that issued the alarm signal, indicating the area where a leak may be occurring.

[0032] The mobile robot has a built-in laser radar used for position synchronization, map building, and obstacle avoidance, with the corresponding driver package installed and the laser radar node rplidar_ros running. The mobile robot uses a Raspberry Pi as the master chip, communicates with ROS via a serial port, controls the robot's chassis using the rosserial or ros_control package, controls the robot's linear and angular velocities by issuing cmd_vel in ROS, provides the mobile robot with action-based path planning based on the move_base method, and enables path navigation for the mobile robot through global path planning and local real-time planning planners.

[0033] Furthermore, two types of cost maps, gloable_costmap and local_planner, can be introduced to the mobile robot to represent the weights of obstacles and paths. Sensors can detect the surrounding environment in real time, and the direction of travel can be dynamically adjusted to avoid obstacles. Multiple cruising points are set, and a single ROS node is created that sequentially accesses these cruising points through the ROS navigation stack and repeatedly sends multiple target points to move_base. After receiving an alarm signal, the mobile robot activates automatic navigation and quickly travels to the area where a leak may have occurred. However, in the event of a natural gas leak, multiple methane sensors may emit alarm signals simultaneously. Based on the alarm signals, it is only possible to confirm that a natural gas leak has occurred in the area where the methane sensors are located, and the exact location of the natural gas leak cannot be determined.

[0034] In step S103, the signal acquisition and positioning unit installed on the autonomous navigation mobile robot detects sound waves generated by the natural gas leak after the mobile robot moves to the leak-prone area based on an alarm signal, and collects the natural gas leak sound wave signal. Specifically, the signal acquisition and positioning unit is equipped with a microphone array to collect the natural gas leak sound wave signal in the natural gas leak area. By collecting the natural gas leak sound wave signal using a microphone array arranged in a circular structure, the spatial resolution of the natural gas leak sound wave signal is improved, the omnidirectional sensing capability of the natural gas leak sound wave signal in the utility tunnel is enhanced, and sound wave signals transmitted from different directions in a complex environment can be effectively captured.

[0035] In step S104, the signal acquisition and localization unit localizes the location of the natural gas leak source through sound wave difference.

[0036] TIFF2026070449000016.tif30170

number

[0037] TIFF2026070449000018.tif19170

[0038] TIFF2026070449000019.tif33170

[0039] TIFF2026070449000020.tif40170

[0040] TIFF2026070449000021.tif17170

[0041] TIFF2026070449000022.tif32170

number

[0042] TIFF2026070449000024.tif19170

number

[0043] TIFF2026070449000026.tif47170

[0044] TIFF2026070449000027.tif64170

[0045] TIFF2026070449000028.tif19170

number

[0046] TIFF2026070449000030.tif49170

[0047] TIFF2026070449000031.tif32170

number

[0048] This application utilizes the acoustic simulation tool Roomsimove to define the propagation path of natural gas leakage sound waves, including multipath reflection and sound wave absorption characteristics, based on the physical parameters of the utility tunnel (e.g., wall material, size, etc.). It also enables the placement of natural gas leakage sound sources at different locations and the generation of acoustic signals from these different sources. The sound source signals include pulse signals and noise and are used to simulate sound sources in a real environment. Specifically, a physical simulation model of the utility tunnel is constructed based on the physical parameters of the utility tunnel, and natural gas leakage sound wave signals are simulated at different locations of natural gas leakage sources within the utility tunnel.

[0049] Next, the time delay difference simulation data for the simulation signals in the physical simulation model reaching any pair of microphone simulation sensors is determined, and a training dataset for the leak source localization model is constructed based on the simulation location of the natural gas leak source in the physical simulation model and the corresponding time delay difference simulation data. Specifically, the arrival time delay difference when the simulation signals reach each pair of microphone simulation sensors is calculated, and this time delay difference simulation data is recorded as an input feature for training the leak source localization model. The simulation location of the natural gas leak source corresponding to each simulation signal is recorded as an output label for training the leak source localization model.

[0050] TIFF2026070449000033.tif56170

[0051] TIFF2026070449000034.tif35170

[0052] The convolutional layer is connected to a max pooling layer after processing to reduce the dimensionality of the data and highlight key features. Next, the feature sequence extracted by the convolutional layer is transmitted to a recurrent neural network (LSTM), which captures temporal dependencies in the time series through the recurrent layer. This allows the LSTM unit to learn the relationships between data across multiple frames, further improving localization accuracy.

[0053] TIFF2026070449000035.tif19170

[0054] TIFF2026070449000036.tif36170

[0055] Here, the mean squared error loss function is given by equation 6 below.

number

[0056] The detection and evaluation index for the leak source localization model is determined according to Equation 7 below.

number

[0057] TIFF2026070449000039.tif58170

[0058] TIFF2026070449000040.tif62170

[0059] TIFF2026070449000041.tif10170

number

[0060] TIFF2026070449000043.tif91170

[0061] TIFF2026070449000044.tif38170

[0062] In step S105, the mobile unit autonomously moves to the location of the specific natural gas leak source.

[0063] Specifically, when the signal acquisition and positioning unit positions a natural gas leak source within the utility tunnel, it feeds back the position of the positioned natural gas leak source to the mobile unit, which then autonomously moves to the corresponding natural gas leak source location.

[0064] Each integrated utility tunnel server may be equipped with a data aggregation unit and a fire alarm unit. When the signal collection and positioning unit positions a natural gas leak source within the utility tunnel, it further transmits the location of the natural gas leak source to the data aggregation unit and fire alarm unit of the integrated utility tunnel server, allowing for timely countermeasures to be taken.

[0065] This application ensures stability, real-time performance, and strong interference resistance for data transmission in complex utility tunnel environments by using a Bluetooth module for data transmission. After the location of the natural gas leak source is determined, location information and natural gas sensor data are rapidly transmitted via the Bluetooth module to the data aggregation unit of the integrated utility tunnel server, i.e., the control center server, and recorded in a MySQL database. This not only ensures the completeness and accuracy of the data but also significantly reduces the response time for accident processing and lowers the possibility of secondary disasters.

[0066] Data collected by all sensors within the utility tunnel is transmitted to a data aggregation unit, stored in a MySQL database, and then transmitted to a digital twin system. The digital twin system dynamically constructs leak source localization by acquiring and processing this data in real time. Throughout this process, a high degree of synchronization is maintained between the virtual model and physical devices in the digital twin system. If the location of the leak source in the physical system changes, the virtual model is updated in real time to ensure consistency in leak source prediction and monitoring.

[0067] The digital twin system can further include an output unit that can visually output the location of the predicted leak source and issue a leak alarm.

[0068] In step S106, the output unit of the digital twin system can visualize the leak localization process, display the location of the leak source, and issue an alarm.

[0069] As an example, the predicted leak source location is visually displayed through the Unity3D platform. Data transmitted via Bluetooth is accessed in Unity3D, enabling real-time access to Bluetooth data based on the installation of InTheHand.Bluetooth via the NuGet package manager, and then communication with the Bluetooth device is performed using the SerialPort class. The data fed back from Bluetooth (location of the natural gas leak source) is analyzed and the corresponding mobile robot's position in Unity is updated.

[0070] By dragging and dropping a UI-Text object into the positionText field using the Canvas tool, the mobile robot's position data is displayed in real time. In other words, the UI-Text component in the Canvas tool is used to update the leak source coordinate information in real time, allowing system operators to clearly see the leak source's location and movement trajectory in three-dimensional space. By combining the Xcharts graphics component with a MySQL database, the digital twin system can display the data inside the utility tunnel in a graphical format. Leak data in the database is visually displayed by calling Mysql.Connector and the Xcharts API.

[0071] Through the Xcharts plugin, various digital charts are built within Unity3D, connected to database data using dynamic linking, Mysql.Data.dll is imported into the Unity Assets folder, then a C# script is created to connect the chart's data source to real-time data in MySQL using the MySQL Connector and APIs provided by Xcharts, SQL queries are performed using command.CommandText, database information is retrieved using the render.Read() method, and finally the chart's data source is changed to real-time data in the MySQL database using data.Add(serial Data) to form a natural gas detection digital twin system.

[0072] In this description of the present invention, terms such as "one embodiment," "several embodiments," "example," "specific example," or "several examples" mean that the specific features, structures, materials, or characteristics described in relation to the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the general expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in an appropriate manner in any one or more embodiments or examples.

[0073] The foregoing are merely preferred embodiments of this application and are not intended to limit it, and those skilled in the art can make various modifications and alterations to this application. Any modifications, equivalent substitutions, improvements, etc., that do not deviate from the spirit and principles of this application should all be within the scope of protection of this application.

Claims

【Request Item 1】 【Number】 [Math 1] [Math 2] [Math 3] 【Number 4】 [Math 5]

2. The system further includes a physical simulation model of the joint utility tunnel constructed according to the physical parameters of the joint utility tunnel, The training dataset for the leak source localization model is constructed based on the simulated location of natural gas leak sources and corresponding time delay difference simulation data in the physical simulation model, and the simulated location of natural gas leak sources and corresponding time delay difference simulation data in the physical simulation model are obtained by using the physical simulation model to simulate natural gas leak sound wave signals at different natural gas leak source locations in the integrated utility tunnel and determining the time delay difference simulation data at which the simulated signals in the physical simulation model reach any pair of microphone simulation sensors, characterized in that the digital twin system for detecting and localizing natural gas leaks in an integrated utility tunnel based on sound source localization according to claim 1.

3.

4. 【Request Item 5】 【Number】 [Math 6]

Images