Design And Implementation Of Monitoring System For Fire-fighting Facilities In Expressway Tunnel

With the continuous development of highway construction scale,the number of highway tunnels in China has ranked first in the world.Tunnel is the most complex section of highway operation environment.In recent years,the number of tunnel fires is increasing.In the face of frequent tunnel fires,if we can use the fire-fighting facilities in the tunnel in time to put out the fire in the "golden 10 minutes" of fire-fighting,we can avoid greater economic losses and casualties.But on the one hand,due to the bad air environment in the tunnel,it is easy to cause the aging and damage of fire-fighting facilities.On the other hand,due to the variety and quantity of tunnel fire-fighting facilities,the efficiency of manual monitoring and inspection is low,it is easy to lead to missing or false detection.Both of the above two reasons will lead to the decline of the ability of tunnel fire-fighting facilities.Aiming at the low efficiency of manual monitoring of tunnel fire-fighting facilities,this paper combines embedded technology and data server technology into the development of tunnel fire-fighting facilities monitoring application,and designs a more open tunnel firefighting facilities monitoring system which can realize the layout of massive sensing nodes.The overall architecture of the system is divided into four parts: perception node,data gateway,data server and client software.The main work includes:(1)This thesis designs a sensing node suitable for the tunnel network environment.This part of the work is mainly completed in three steps.First,at the data link layer,a hardware circuit based on the Marvell 88W8801 chip is designed to realize the goal of sensing nodes to use Wi-Fi to access the wireless local area network;at the application layer,it is the basis for porting the TCP/IP protocol stack of LWIP The Modbus/TCP protocol is used to complete the data exchange between the sensing node and the data acquisition gateway to realize the reasonable access between multiple sensing nodes;secondly,the RS485 data acquisition interface is designed in terms of data acquisition,which realizes the realization of various types of sensors.Data collection;Finally,the software and hardware development work of the sensing node is completed.(2)In terms of data gateway,taking advantage of Modbus/TCP’s fast speed and strong consistency,a simple and efficient data exchange method is designed to cope with the access of massive sensing nodes.At the same time,using the My SQL database’s high availability and fast data query speed,a data table model is designed to realize large-scale data storage and high-speed data query.(3)In terms of data server and client software,the open source proxy server Nginx is used as the HTTP server,My SQL is used as the database,and the unified interface of the REST architecture and the characteristics of data resources as the center are used to provide unified data for multiple clients Interface service.Finally,the Python programming language is used to complete the development of data acquisition gateway,data server and client software.Through field tests and experiments,sensing nodes and data collection gateways can efficiently complete data collection,processing and storage.The data server and client software can display and monitor the health status of fire-fighting facilities in real time,and can provide timely feedback on non-health warnings in fire-fighting facilities.The whole system can effectively guarantee the fire-fighting response capability of the tunnel firefighting facilities,which proves that the highway tunnel fire-fighting facility monitoring system designed in this paper has certain use value.