Research On The Key Technology Of Traffic Guidance System For Fatal Emergency Evacuation

In recent years, it is frequently occurred of major disasters in the world, such as the,"9.11" terrorist attacks of United States, South Korea subway fire incident, bombings of London transit system, the Indian Ocean earthquake and tsunami disaster, "Katrina" hurricane of the United States, We chuan earthquake and the South snow and ice storms in china, which had a serious impact on the road traffic system, causing huge casualties and property losses. A variety of major disaster events is not only a test of emergency response capacity of Governments, but also put forward higher requirements for emergency response capacity of the road transport system.Road traffic is the most widely used for transport security, which have the significant disaster vulnerability. It often becomes the weak link when the evacuation and rescue. In the major disaster conditions, safety and unlocked of road is the important prerequisite for rescue and evacuation. Fast and effective emergency transport organizations can significantly reduce life and property losses, which can reduce the disaster losses to minimum. Therefore, the world's countries are active in emergency relief Theory and Technology for sudden accidents with major disasters, which need establishes a relatively perfect emergency system. Because of the complexity of major disasters Impact on the road transport system, traffic technology of emergency evacuation and rescue also can not meet the disposal needs of disaster events.As an important part of traffic organization under the major disaster conditions, the ability to respond to major disaster events of urban traffic guidance systems largely determined the implementation of traffic effects of emergency evacuation and rescue, the existing urban traffic guidance system respond to major disasters have the following problems:1) The comprehensiveness, timeliness, reliability difference of dynamic traffic information. Road travel time is the most intuitive traffic parameters reflected traffic state, which is the data basis for the emergency evacuation and rescue of traffic guidance system. Now the existing traffic guidance systems rely on detecting coil which extract the travel time. It is difficult to achieve the comprehensive road network throughout the layout of detecting coil; GPS floating car represented the car-based traffic information extraction equipment, whose precision strictly limited by the sample size. In the sections of dealing with the travel time,it is disadvantage of considering the data prediction and fusion technology.2) Navigation electronic map can not be updated real time. The occurrence of major disaster events will affect the urban road network or completely destroyed the basic functions of the road, or partly change the road. Current navigation map update cycle is too long (one year). It can not reflect the major disaster event in real-time changes of the road, which can easy guide the driver wrong road line, causing the chaotic traffic, traffic congestion, serious traffic safety hazards.3) Lack of technology support for emergency evacuation and rescue route optimization. The path optimization of existing traffic guidance system does not consider the need of emergency evacuation and rescue. Under the conditions of the major disaster, it has serious damage to the road traffic capacity .Also demand of emergency transportation surge will be explosion. If the method used in the normal state is still utilized for the evacuation and rescue plan moving vehicles line, it will delay the timeliness of evacuation and rescue, which lead to significant aggravation the consequences of disasters. Based on this background, Ministry of Science and Technology instituted thematic issues named 863 Program to research traffic security technology under a major disaster jointly by Jilin University, Wuhan University, Academy of Transportation Sciences and De Zhou Highway Survey and Design Institute. City Emergency Traffic Guidance System is the important part of traffic security technology under a major disaster, the crucial point of ensuring the effect for emergency evacuation and rescue, which the purpose is providing technical support for improving urban road traffic system's emergency response capacity and highly theoretical study and practical significance. Consequently, this article relies on the national "863 Program" topic(2009AA11Z218,2009AA11Z208 and 2007AA12Z242)to progress research and discussion throughout by researching City Emergency Traffic Guidance System under a major disaster. As the full-text is divided into six chapters, the chapter 2, 3, 4 and 5 researches focus of this article, of which the chapter 3, 4 and 5 are the core of this research. Chapters 1 and Chapter 6 respectively include research background, meaning and ideas introduced and the summary and outlook of the full text .This study focused on several key technologies including urban emergency traffic guidance system framework design, link travel time extraction, navigation map induced by the Method of Updating under emergency traffic conditions, emergency transport induced path optimization. It continued to:1)Construction design of urban emergency traffic guidance systemThis paper mainly introduces the concept, composition and application status of urban traffic guidance system. Combined with the impact analysis of major disasters on urban road transportation system, it put forward the system components, the physical framework, the logical framework, key technologies of emergency response capabilities, and the system functions of urban emergency traffic guidance system. 2)Extraction technology of road travel timeThe paper introduces and analyzes the research status of road travel time extraction, including the collection, forecasting, and integration of road travel time. Then it pointed out the shortcoming of the existing road travel time extraction technology applied to the area of major disaster events, giving the corresponding solution method. First, based on the analysis of foundation traffic information type and vehicle-based traffic information collection device type of road travel time estimation methods, using remote sensing Images"wide coverage " features, we combined with traffic flow theory and proposed the road travel time estimation based on space-based sections device. It realizes the wide range of travel time data's comprehensive collection. Then combined with the information need of emergency traffic guidance system ,we developed the road travel time short-term multi-step prediction technology based on multi-model integration, which improve the road travel time data availability. Finally, based on the analysis of different sources of data accuracy of road travel time, considering the major disaster events impact on traffic information collection technology, we apply the neural network and proposed the rapid integration of technology based on the reliability of the road travel time, providing for urban emergency traffic guidance system high-quality data base. Changchun measured data validation results show that the technology and method has good accuracy and effectiveness.3)Navigation electronic map quick updating method of urban emergency traffic guidance systemThis paper analyzes the major disasters impact on the urban road network and introduced the space-time navigation data model and navigation electronic map updating mode research. First, guiding by the concept of object-oriented, we analyze the objects of GIS-T and objects of dynamic traffic information on the temporal characteristics, built road network and dynamic traffic information integrated with the spatial and temporal data concepts modal, utilizing the UML standard modeling language to set up the road network and the integration of space-time dynamic traffic information data logic model. And then, based on the analysis of navigation data on the partial renewal of the timeliness, we proposed the sub-regional organizations method with the spatial data of road network and topology data and established the road block network data storage structure; Finally, by fitting judgments of nodes, sections intersection processing methods to realize the incremental data and sections of the road network to add, delete, modify operation of the intelligent interface, we designed quick way to update the map process.4)Route optimization technology of emergency traffic guidanceIn the article from the emergency evacuation route optimization technology aspect, analyzing the particularity of the behavior under the Disaster Environment Vehicle Route to make a choice。established based on the route order of complexity and the evacuation time double goal emergency dispersal way optimization model, under background of total time in evacuation process needs is minimum , consider minimum complexity of evacuation routes as one of as optimized goals; In the emergency transportation rescue route optimization techniques aspect, Broke the erroneous zone of equate the emergency transportation rescue way to optimize with the shortest distance calculate graph theory, established based on the reliability of travel time , the reliability of the route connection, securely of the route the emergency transportation multi-objective way optimization model.The aim of this traffic guidance systems is to enhance emergency response capacities, to a major disaster under the conditions of transportation emergency guidance system for the study, used mathematical statistics, artificial intelligence, GIS technology and other advanced technology and methods as a means to study, including link travel time extraction, emergency traffic conditions induced rapid updating electronic map, emergency transport induced traffic path optimization, including emergency guidance system core and key technologies, validation results showed that: the above techniques all have a good effect, is easy to operate, greatly enriched under significant disaster condition the Transportation organization of Traffic technological achievements.In recent years, with the rapid social and economic development, concentration degree of population, construction, production, wealth relative increased. Emergency major disasters in China have not only increased the frequency, but also increased the damage degree. The most cities generally established the traffic information platform, and on this basis to develop the urban traffic guidance, control, simulation core subsystems of ITS. If we can apply the article's technology to Transportation Guidance System of major cities, it will greatly improve the system's emergency response capacity. Also under the conditions of disaster, it can give full play of the existing traffic infrastructure, which can ensure the evacuation and rescue safety, fast, efficiency, smooth, reduce the loss of life and property and so to control hazards to the minimum.