Study On Modeling And Control Of T-CPS Cooperative Vehicle Infrastructure System For Traffic Efficiency

Traffic congestion is becoming more and more serious,which greatly restricts the efficiency of road traffic operation.In fact,the problem of vehicle running efficiency is partly caused by the problem of vehicle road coordination and Traffic evolution.Therefore,the modeling and control of vehicle-road cooperative driving will be helpful to further study the internal principle.and effective methods of improving traffic efficiency.Using the new information technology and control technology,taking the deep integration of information system and physical system as the breakthrough point,and making full use of the seamless integration of traffic information to traffic physical system,the interactive feedback between traffic information system and traffic physical system can be realized,which is expected to provide a new perspective and effectiveness for solving the problem of improving traffic efficiency.From the perspective of Transportation Cyber Physical Systems(T-CPS),this paper focuses on the traffic modeling and control strategy for improving the efficiency of super highway,Expressway and urban road.Aiming at the automated platooning used in super highway,the dynamic modeling of T-CPS vehicle and the control strategy of automated platooning considering fault-tolerant control are studied.Aiming at the car-car cooperative car-following system used in expressway,the car-car cooperative car-following model considering the information of continuous historical speed difference is studied.Aiming at the problem of vehicle-road cooperative control in the near-signal area of urban roads,a model predictive control(MPC)based variable speed control strategy is proposed.The research work of the paper is mainly carried out in the following three aspects:(1)The operation mechanism and control strategy of vehicle-vehicle cooperative automated platooning system used in expressway are studied.From the point of view of physical fusion of traffic information,a T-CPS vehicle dynamic model considering physical factors of vehicle information is established.The model is used to build an automated platooning and a fuzzy PI controller is designed for the following vehicle.Considering the influence of vehicle fault factors on vehicle platoon,a fault tolerant control strategy for automated platooning vehicles is designed.The simulation results show that the T-CPS vehicle dynamic model can easily reproduce the internal and external running rules of the vehicle after fault.At the same time,the fault-tolerant control strategy of automated platooning based on this model has good fault suppression ability to ensure the platoon running stably in case of vehicle failure.Under the condition of ensuring safety,we can shorten the distance between cars and improve the efficiency of road traffic.(2)Aiming at the car-car cooperative car-following system applied in expressway,the influence mechanism of continuous historical speed difference information on car-car cooperative car-following is studied.From the view of T-CPS,a vehicle cooperative following model considering the information of vehicle historical speed difference is proposed.By analyzing the linear stability of the model,the vehicle flow stability condition of the model is deduced.In addition,by nonlinear analysis of the model near the equilibrium point,the dynamic evolution behavior of vehicle flow described by mKdV equation is obtained,and the model is simulated.Through theoretical analysis and simulation experiments,it is found that the stability region of sensitivity space can be enlarged by increasing the time length of considering historical velocity difference information.Considering the longer the historical speed difference,the better the stability of road traffic flow.(3)Aiming at the problem of traffic efficiency in the near signal area of urban roads,the strategy of vehicle road cooperative variable speed limit control is studied.From the perspective of T-CPS,the Intelligent Driving Model(IDM)of near signal control area is introduced.By taking full account of the road information set and vehicle dynamics constraints,a variable speed limit control strategy is designed using nonlinear model predictive control technology to achieve near-signal control area vehicle dynamic speed guidance.The simulation results show that the control strategy can improve the traffic flow in the signal control area under high traffic density.Combining with the measured communication performance parameters,the simulation results show that extending the wireless communication distance can increase fuel economy.In the case of low traffic density and high traffic density,extending the wireless communication distance can improve road traffic efficiency.