I. Introduction
In the construction of modern urban infrastructure, tunnels and utility tunnels undertake key functions such as transportation, energy transmission, and communication. However, due to the complex internal environment, there are many potential safety hazards and management challenges. As an emerging wireless communication technology, the UWB (Ultra-Wideband) module provides an innovative solution for the intelligent management of tunnel utility tunnels with its unique advantages, and is becoming the focus of industry attention.
II. Overview of UWB Module Technology
(1) Technical Principle
UWB technology communicates and locates by transmitting and receiving extremely narrow pulse signals in the nanosecond or even picosecond level. These pulse signals occupy an extremely wide frequency spectrum range from several hundred megahertz to several gigahertz. Its positioning is based on the measurement of the signal's time of flight (ToF, Time of Flight). The UWB tag and the base station transmit and receive UWB pulse signals to each other, and accurately calculate the distance between them according to the signal propagation time combined with the speed of light. By using the distance information of at least three base stations and the tag, the spatial position of the tag is determined through the triangulation algorithm to achieve high-precision positioning.
(2) Technical Characteristics
High-precision positioning: The UWB module can achieve centimeter-level positioning accuracy, which has significant advantages compared with positioning technologies such as Bluetooth and Wi-Fi. In the tunnel utility tunnel environment where the accuracy requirements for the positions of personnel and equipment are extremely high, it can accurately grasp the real-time positions, effectively avoiding safety accidents such as collisions and misoperations.
Strong anti-interference ability: The UWB signal has a unique waveform and an extremely wide frequency spectrum, and is not sensitive to channel fading phenomena such as multipath effects and non-line-of-sight propagation. The space in the tunnel utility tunnel is narrow and the structure is complex, and the signal is easily interfered by reflection and scattering. However, the UWB module can work stably to ensure the reliability of positioning and communication.
Low power consumption: The UWB module has low power consumption during operation, which is extremely important for the application scenarios of tunnel utility tunnels that require long-term continuous operation. For example, the UWB positioning tag can be powered by a battery. The low power consumption extends the battery life of the tag, reduces the trouble of frequent battery replacement, and lowers the maintenance cost.
Good penetrability: The UWB signal has a certain penetration ability and can penetrate obstacles such as concrete walls and metal pipes. Even if the signal strength attenuates after penetration, it can still maintain effective communication and positioning functions. In the tunnel utility tunnel, even if there is partial occlusion between the tag and the base station, positioning can be achieved to ensure the comprehensive coverage of the positioning system.
III. Application Scenarios of UWB Modules in Tunnel Utility Tunnels
(1) Personnel Positioning and Management
Real-time position monitoring: During the construction or operation and maintenance of the tunnel utility tunnel, UWB positioning tags are worn by the staff, and UWB positioning base stations are deployed inside, so that the accurate position information of the personnel can be obtained in real time. The management personnel can intuitively see the real-time position distribution of the personnel in the tunnel utility tunnel on the monitoring center platform, which is convenient for reasonable dispatching and improves work efficiency. For example, when urgently allocating personnel to perform tasks, the nearest personnel can be quickly found and given instructions.
Attendance management: The UWB positioning system automatically records the time when the personnel enter and exit the tunnel utility tunnel and the residence time inside, achieving accurate attendance. It helps enterprises accurately count the working hours of employees, avoid attendance loopholes, and can also trace the work trajectory of employees to understand their work status.
Safety early warning: With the help of the electronic fence function of the UWB positioning system, virtual fences are set up in dangerous areas of the tunnel utility tunnel (such as the construction area, near high-voltage equipment, etc.). When the personnel wearing UWB tags enter the dangerous area, the system will immediately issue an alarm to remind the personnel to pay attention to safety, and at the same time send a warning message to the management personnel to prevent accidents in a timely manner. When the personnel remain stationary in the utility tunnel for a long time (they may suddenly fall ill or encounter an emergency), the system can also detect and alarm in time for quick rescue.
(2) Equipment Positioning and Tracking
Construction equipment management: During the construction stage of the tunnel utility tunnel, large-scale equipment such as excavators, loaders, and transport vehicles operate frequently in a limited space. By installing UWB vehicle-mounted positioning devices on these equipment, the positions and operation trajectories of the equipment can be grasped in real time. This is not only conducive to the reasonable arrangement of the operation route to avoid equipment collisions, but also can count the usage of the equipment, such as working hours, idle time, etc., providing a data basis for the maintenance, repair, and dispatching management of the equipment.
Inspection equipment tracking: During the operation and maintenance of the tunnel utility tunnel, inspection personnel carry inspection equipment to check the facilities of the utility tunnel. By equipping the inspection equipment with UWB modules, its position can be tracked in real time to ensure that the inspection personnel work according to the predetermined route and avoid missing inspections. When the inspection equipment detects an abnormality, it can transmit the data to the management center in a timely manner through UWB communication and mark the abnormal position on the map for convenient subsequent processing.
(3) Safety Early Warning and Emergency Rescue
Collision early warning: There is a high risk of collisions between vehicles and vehicles, and between vehicles and personnel in the tunnel utility tunnel. The UWB module can realize the mutual distance measurement between vehicles and vehicles, and between vehicles and personnel. When the distance is too close, the vehicle-mounted positioning device or the positioning tag worn by the personnel will automatically trigger the collision early warning to remind the driver and relevant personnel to avoid, effectively reducing the probability of collision accidents. For example, in the narrow section of the tunnel utility tunnel, when the distance between two vehicles driving towards each other approaches the dangerous threshold, the system will issue an alarm in time to avoid a collision.
Rescue in case of emergencies such as fires: Once a fire occurs in the tunnel utility tunnel, smoke will quickly fill the space, seriously affecting the vision and escape routes of the personnel. At this time, the advantages of the UWB positioning system are highlighted. The positioning tags worn by the trapped personnel continuously send position signals in the smoky environment. The rescue personnel can receive the signals and quickly and accurately find the trapped personnel in the complex environment, improving the rescue efficiency and buying precious time for the safety of the personnel's lives.
