Research On The Problem Of Emergency Relief Of Virtual Guided Train

For a long time,in order to relieve traffic pressure and achieve sustainable development,China has vigorously promoted the construction of public transportation and advocated the green travel lifestyle.In the Outline of the 14 th Five-Year Plan of China,the goal of building a transportation power is defined.In the field of public transportation,it is proposed to develop a new intelligent transportation industry that ADAPTS to the urban economy and urban governance,so as to realize the long-term goal of "people enjoy their travel" for a transportation power.As a new intelligent transportation method of urban public transportation system,virtual guided train can guarantee residents’ travel and improve the coverage rate of public transportation service.However,in the development and construction of the virtual guided train,the safety problems brought by emergencies cannot be ignored.Therefore,it is necessary to study the operation safety problems of the virtual guided train,a new intelligent transportation.In this paper,the problem of emergency relief of virtual guided train is studied.The main research contents are as follows:(1)the virtual orientation under the emergency transport system security features has carried on the detailed analysis,build the virtual orientation train accidents emergency relief scene,put forward to evacuate traffic flow distribution,and then based on the evacuation traffic flow distribution results intersection signal timing optimization strategy of two phase of emergency relief The evacuation traffic flow under the emergency of the virtual guided train can pass quickly and reduce the adverse effect of the emergency of the virtual guided train on the road network.(2)In the distribution of evacuation traffic flow,BPR function is selected as the road resistance function.With the help of VISSIM simulation software,evaluation files are configured and the input traffic volume is continuously increased to obtain simulation data.The relevant parameters in BPR function are demarcated for the general road section,the road section where the virtual guide train runs and the road section where the virtual guide train has an emergency.The optimal traffic flow allocation model of the system was used to allocate the evacuation traffic flow,and Frank Wolfe algorithm was chosen to solve the problem.(3)After evacuation traffic allocation,the flow direction of nodes changes,so it is necessary to optimize the timing of intersection signals.Firstly,a single-point signal timing optimization model is established to improve the ability of vehicles to pass through the intersection and reduce the average delay of vehicles.Then,the coordinated control among intersections was considered,and the correlation degree model of traffic volume,intersection spacing and cycle was established to carry out line coordination control for the intersections with strong correlation degree,so as to further improve the evacuation efficiency of the network and enhance the safety attribute of the system.(4)The case study of Tianyuan District of Zhuzhou,where the A1 line of the virtual guide train runs,shows that when the virtual guide train has an emergency,the evacuation traffic flow allocation is carried out to achieve the equilibrium at the network level,and the total travel time in the system is reduced by 4.5%;The signal timing of single-point intersection based on evacuation traffic flow allocation reduces the delay of No.5 intersection affected by emergencies by 87.81%,and increases the capacity by 51.94%.In line coordination control,the delay of No.5 intersection participating in coordination control is further reduced.