Research On Tunnel Monitoring System Key Technology

With the rapid development of the national highway and industrial automation technology, the digitization, visualization, networking and intelligent have been implemented gradually on the operation and management of the highway tunnel. Tunnel monitoring system can monitor tunnel traffic real-timely, dynamically and informationally. It can also manage and control all tunnel mechanical and electrical equipments centrally. Based on the tunnel monitoring system design project of the national Shi-Tian (Shiyan-Tianshui) highway, the key technology of tunnel monitoring system that the paper focuses on is to provide solutions for control strategy, using the upper configuration software and a lower programmable logic controller to solve the tunnel traffic, ventilation, lighting automatic control problems.First, the research status of tunnel monitoring system both at home and abroad is introduced. The overview of tunnel monitoring system is expounded on the basis, design principle and scale of the system. The overall goal, structure composition and control mode of the system are determined. Specific functional requirements of the system are analyzed in detail.Secondly, the upper configuration software subsystem and the lower programmable logic control subsystem in the system are introduced. The structure, function, hardware configuration and software development procedure are designed and completed in detail. Software user management and hardware redundancy are designed respectively for security and reliability.Finally, the software to human-computer interaction interface and its control strategy is completed in the traffic control, ventilation, lighting control and fire alarm linkage control subsystems. According to the tunnel traffic forecast analysis under different working conditions, the reasonable traffic induction control pre-arranged planning and fire escape strategy to abnormal traffic are established. The feedback intelligent ventilation control scheme based on tunnel ventilation design specification and standard is adopted to make the environmental parameters in a safe range, for example, CO density, visibility, wind speed and direction. According to the actual requirement of tunnel lighting and brightness sensor detection data, the manual control, automatic control and sequential control modes of tunnel lighting are implemented respectively to solve the lighting control problem under different status of climate and time. To meet control demand of the fire extinguishing system under fire,the fire alarm linkage control is realized, and the state of fire pool is displayed real-timely inthe monitoring system.The tunnel monitoring system of national Shi-Tian highway was operation in July2012.The system is running stably and reliably. The centralized management and control of tunnelmechanical and electrical equipment are implemented. The results show the advanced natureand rationality of the system solution.