Design And Realization Of Shandong Expressway Monitoring-Guidance System

At present, china's rapid economic and sustainable developments produce a large number of transport demands for the road, especially the expressway. In order to enhance the effective use of the expressway, reduce and prevent the traffic jams and traffic accidents or traffic chaos on the highway, and to achieve efficient and automatic traffic control and guidance is very necessary. The traffic guidance information issued to the highway traffic induced an important part of the traffic guidance system to achieve. In the information obtained by establishing the basis of the highway traffic guidance information dissemination system, reduce traffic jams and other traffic events; raise the utilization of roads and traffic management efficiency.This paper analyzes the current status of traffic guidance system, and then based highway monitoring system in Shandong, according to the distribution of total high-speed management center and sub-centers, design the total, sub-center monitoring system of the upper, the underlying communication service system of systems architecture. In detail the function of each system partition is presented after in a detailed analysis of their needs.In the underlying communication server, through the design of a field device class, so the main thread according to the actual field device is set to dynamically generate multiple field device class object, a good solution to the communication server on a number of field devices polling the key issues. Shorten the polling hours, to avoid failure in the polling in the other special reasons for the deadlock situation. Another class of command messages through the design, so that field device class object implements the control command in the poll with the top handle on the scheduling algorithm.In the upper monitor screen, using MapInfo plug-in implements the electronic map display, and the design and implementation of the optical band and other electronic display screen shows the effect of simulation. End-use serial communication technology, computer network technology, database technology and digital maps, such as design and implementation of the system.Currently, the system has been in Shandong Highway Information Management Center to run successfully, is responsible for the section of Beijing-Shanghai high-speed Shandong Dezhou, Jinan, Tai'an, Zaozhuang part of the four sub-centers in the variable information and intelligence panels, variable speed limit signs, light bands variable information board, and other field equipment, monitoring and management work, and has good scalability.