Research Of Highway Tunnel Vehicle Positioning System Based On WSN Technology

For the current highway tunnel fire prevention, the supervisory system are unable tocarry on the accident to forewarn effectively, and unable to locate the accident spot and thecondition accurately after the accident occurs, this article studied and designed a tunnelvehicles localization monitor system based on the wireless sensor network, in order to thereal-time monitoring of the tunnel vehicles running status. This system can forcus on thedangerous material carrier vehicle, make an early warning of fatal accidents by the dangerousmaterial vehicles, and may monitor the tunnel transportation condition in the real-time, whenthe accident occurs, this system may not only locate the accident spot and the conditionaccurately, but also follow up the rescue situation, providing a reliable basis for the successfulrescue of intelligence work to achieve comprehensive monitoring of highway tunnels.This paper built a wireless sensor network based on Zigbee technology, first analyzes thetransmission mechanism and characteristics of electromagnetic waves in a tunnel in space,according to the wave field intensity distribution in the tunnel were divided its propagationarea, and based on Fresnel theory validated region electromagnetic transfer characteristicsmeet the tunnel near field free space model conclusion on the basis of a function using the TRfield deduced RSSI-D model, and fitting the large amount of data collected according to thetunnel environment based on RSSI ranging function; then, for defects commonly positioningalgorithm, combined tunnel environment, is proposed based on the integration of RSSI-APITlocalization algorithm to improve system performance; Finally, depending on the condition ofexisting tunnel electromechanical systems, from the overall framework for the study of thesystem, combined with design algorithms, proposed a isosceles trapezoid sub-locationnetwork node layout mode, while the major software modules to build the hardware platformdesign and various nodes were studied.After the mathematical model of the system to simulate the distribution of nodes, thesystem for a number of simulation accuracy, fluctuations in the positioning error of3%to6%,and mainly in the traveling direction of the vehicle, can basically meet the positioning requirements.The system can be integrated into corrent communications, tunnel monitoring system as asubsystem of the tunnel electromechanical system to achieve the positioning of the tunnelvehicle tracking, real-time monitoring of potential risk factors, the existing monitoring, firealarm system is perfect, achieve accident warning, positioning and remote monitoringfollow-up accident rescue, to facilitate timely adjustment tunnel accident treatment strategyhas some practical value in the tunnel management.