Research On Collaborative Design Of Heterogeneous Sensors Network For Highway Network Operation And Management

Highway network is one of the most important infrastructures,which supports social economic,personal travels,and national security.In the end of 2014,the total length of Chinese highway has exceeded 112,000 km and preliminarily constructed the planned network system,on which more than 30%of road passenger transport and freight transport were carried.Meanwhile,the increasing of travel safety needs,social mobility,cross-regional passenger travels,as well as adverse weather frequency has raised higher requirements towards extensiveness highway network management and services,and this has merged the traditional highway construction and management to traffic monitoring and emergency responses.In order to fulfill these new demands of management and operation,such as integrated transportation network service,advanced highway network service,and emergency coordination and response,the highway operation agencies need to have:1)reliable network status assessment and prediction;2)rational design of traffic monitoring and control network;3)proactive incident area avoid guidance.Thus a rational design of highway traffic sensors network which could support regional network monitoring,emergency response and public service is eagerly in need.At the same time,with the development of information communication technology,traffic monitoring and surveillance technology have less relying on traditional segment detectors.The expressway vehicle-to-infrastructure communication platform with Dedicated Short Range Communication(DSRC)technique has been developed rapidly.With the development of Unmanned Aerial Vehicle(UAV)technique and gradual opening of low-altitude airspace,the mobile sensors such as UAV have been applied in network management.To rationally design and distribute a multi-source heterogeneous traffic sensor system with the new generation of traffic monitoring technology is the main objective of this study,this thesis is expected to fulfill the new demand of highway network management and operation,support highway coordinative control,as well as provide reliable public travel services.This study started with the Optimization Planning Theory and the Traffic Assignment Theory,considered the improvement of network control and management and service as main goal.This thesis studied critical segment identification method based on equilibrium traffic assignment,proposed optimal DSRC network design method with network observability and controllability,developed a UAV dynamic routing planning model towards network status detecting.In detail,this study includes:(1)Applicability of multi-source heterogeneous sensors analysis.This paper analyses the main requirements of road network management and monitoring elements.Through analyzing the detecting parameters,data quality,costs and the applicability of network management requirement of multi-source heterogeneous sensors,which lay the groundwork for optimal design of multi-source heterogeneous sensors.(2)Research on critical segments set identification based on equilibrium traffic assignment.This paper develops the critical segments assessment model based on K-shortest path and user equilibrium traffic assignment by considering network structure,traffic demand,and travel behavior impacts.In order to investigate the combine effects of multi-segments failure,a critical road segment identification model is proposed based on failure probability distribution of road segment.Further study by introducing road segment invulnerability or rescue recovery costs and capacity constraints,this paper constructs a critical road segment identification model based on recoverability,which has been verified by using different networks.(3)Research on DSRC network optimization based on network observability and controllability.DSRC has two-direction communication function which can realize the network status information collecting and routing information pushing simultaneously.Based on the network surveillance and management requirements,this paper proposes a framework of network observability and controllability to minimize network travel time uncertainty and minimize total travel time which is verified by highway corridor.By using this model,the optimal DSRC network could be constructed for different control and management strategies.(4)Research on UAV dynamic route planning for network state detection.Considering network physical topology structure and space-time propagation of incidents,this paper proposes an UAV route planning model by introducing time geography theory and requirements of combine fast incident detection and general inspection.The objective of this model is minimize delay detection cost of UAVs and fixed sensors on space-time network,and the flying cost of UAVs and construction cost of fixed sensors are considered as budget constraints.The Lagrangian relaxation solution framework is developed to solve this model for fixed sensors known and unknown conditions.For the fixed sensor known case,this model will be simplified as the typical time-dependent shortest path problem.This model is verified by using different scales of network.