Research On Extension Control Method Based On Regional Road Network MFD

The development of society makes the use of cars increase rapidly,however,the congestion problem of urban road network which is mostly regional traffic congestion is becoming more and more serious.Therefore,the research of macroscopic road network control is particularly important.As an effective means to study the regional road network,the study of the macroscopic fundamental diagram(MFD)has also been gradually deepened.At present,the research of MFD is relatively fixed.Mostly regard the MFD of fixed area as the research object,however,the boundary of regional road network varies with time,especially at traffic congestion area.Taking the urban congestion area road network as the research object,based on the MFD theory,this paper studies the dynamic selection at the road network boundary in urban congested area,and the extension control based on the MFD curve characteristics.The research of this paper mainly includes the following aspects:(1)Based on VISSIM simulation software,the simulation experiment is carried out with the actual road network with an area of about 20 km~2.The variation characteristics of congested area scope with time and the change trend of MFD in different regional road networks are discussed.(2)According to the changing characteristics of the regional congested scope,the extension theory is applied to evaluate and select the links connected to the congested area,and the extension evaluation selection model of the congestion area is designed to select the boundary of the congestion area.The PI control method is used to control the boundary of the changing regions.It is called the external PI control,called EPI.(3)According to the characteristics to the characteristics of the volatility of MFD,choose the difference between the actual completion rate and the center curve as the characteristic quantity,and divide the wave area into two regions,the classical domain and the extension domain,and set up the internal extension controller based on the PI control.(4)Finally,the internal extension control and external PI control are combined,called EPIE,and carry out it in urban road network.An actual road network in Hefei is selected to carry out an example analysis,and compares the PI control with the EPI control and the EPI control and the EPIE control method respectively.The experimental results show the effectiveness of the EPI control and EPIE control methods.